The Flat Earth Society

Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: Bobby Shafto on April 25, 2018, 09:03:48 PM

Title: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 25, 2018, 09:03:48 PM
"A fact of basic perspective is that the line of the horizon is always at eye level with the observer."
https://wiki.tfes.org/Horizon_always_at_Eye_Level (https://wiki.tfes.org/Horizon_always_at_Eye_Level)

If this "fact of basic perspective" is true, I believe it can only be true for perspective at eye-level over a plane (flat) surface).

For perspectives from an eye-level height of a plane tangent to a curved surface, the horizon will not always be at eye-level.

This would make observations of horizon relative to eye-level a potentially good indicator of whether or not one is viewing that horizon over a flat or a curved surface.

Is there anything wrong with that line of reasoning?
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on April 25, 2018, 09:20:30 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 25, 2018, 09:26:19 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 25, 2018, 09:37:28 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?

https://www.youtube.com/watch?v=NqOQ_BCtqUI
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on April 25, 2018, 09:40:29 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?
Yes. Again, the flat earthers didn't understand any of the evidence presented. They claimed that the u-tube wasn't at eye level.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 25, 2018, 10:01:31 PM
Define "eye-level".

I hadn't thought to ask that question, but good idea to define so that we're all on the same sheet of music.

I assumed "eye level" was a sight line at same level as the eye, parallel to the surface.

(http://oi63.tinypic.com/24ply1h.jpg)

The same geometry would apply if the surface is curved, but replace the last phrase with "parallel to a tangent of the curved surface."

"The horizon is always at eye level" means (to me) that no matter the height above the surface, the horizon will appear in line of sight with no inclination or declination. It "rises" to eye level without having to angle sight line down from the horizontal.

Is that correct? (Flat earth proponents?) 

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 25, 2018, 10:10:43 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?

https://www.youtube.com/watch?v=NqOQ_BCtqUI
Yowza!  That's pretty much what I was thinking about doing.

But I thought I'd invite the community here to talk it through first: what am I measuring. How should I be sure to do it (and document it). And make predictions about the results or analysis of predicted results. Do all that before putting in the effort.

The wiki is making the claim and using that as the basis for a flat earth argument about horizons. I thought it might be worthwhile to test the claim.

Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 26, 2018, 12:21:07 AM
And recently i measured, with an accurate sextant, the angle across the sky from horizon to horizon south to north, and guess what? I got over 180 degrees, proving the horizon is not at eye level.

No FEer challenged my accurate, repeatable, and conclusive observations/experiment, which pretty much qualifies as Empirical evidence and the trump card in Zetetic processes.

So I my conclusion is that the FE movement is pretty much dead.
Title: Re: The Horizon is Always at Eye Level
Post by: SiDawg on April 26, 2018, 01:52:50 AM
Yeah it's a particular frustrating area. They write that they understand why the horizon rises with eye level, and they're "kind of" right, but they don't understand why it does that mathematically. They mention 3d games and turning off clipping... they're exactly right in that example! A computer game CAN mathematically calculate for infinity, and so the horizon will appear at eye level. But they don't actually seem to understand HOW this works... if they did, then they'd understand how perspective works, and if they understood that then they'd understand why the flat earth doesn't work :P

I've tried explaining this to them: look 2 meters in front of you, roughly 45 degrees to a parallel site line. Look 4 meters in front of you. roughly 30 degrees... etc... very simple maths to calculate that angle, and it literally never reaches "0": it would have to be 0 for it to appear on that parallel line. In mathematical terms, you can express the "limit" for the angle as 0 when the distance is infinite... but i'm pretty sure not even the FEers think they are seeing to infinity (even if they do believe the earth stretches infinitely) on account of the earth having an atmosphere n'all

So they're "kind of" right? In a way? The horizon "kind of" rises to eye level on a flat earth as well as a globe earth, in that it gets really really close, and appears level... but you have to understand the maths, you have to understand perspective, and you have to understand how the eye resolves things that are "really close to zero".

From that starting point, from an understanding of how things SHOULD appear on a flat earth, then we can quite easily show how that's not the case (and the video above is a perfect example of this, yet they dismiss it for some reason. Very frustrating). Basically their argument is "well the horizon looks like it's at eye level, so therefore the earth is flat"
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 26, 2018, 04:49:01 AM
I confess I don't understand the horizon in a flat model. As I think I understand it, the FE "horizon" is a perceptual one (apparent) that occurs level to height of viewer (0° to the horizontal), but isn't a measurable distance. It depends on acuity (resolution) and obscuring factors in the air.

(http://oi67.tinypic.com/zlbw2e.jpg)

The horizon on a convex curved surface is a geometric point, calculated by height of viewer and radius of the curve, but it's always some angle below the horizontal, though appearing to be at horizontal for low values of h relative to r.

(http://oi66.tinypic.com/es9ohy.jpg)

If so, then I think that if you can demonstrate that the horizon drops below horizontal eye level with increasing height, it supports a curved surface. If the horizon appears consistently at the horizontal at all values of h, it would support the flat earth claim.

Does that make sense?

If so, the next step is to find agreement on how best to measure and document the horizon vs. "eye level" at different heights above the surface. I have some ideas, and I have easy access to viewpoints from sea level to 1500' with clear views to an ocean horizon, though catching a non-hazy day for a good horizon contrast is hit and miss this time of year.

I like the idea of a water level that's not cumbersome to tote on a hike, but I'd want it to be set up on a stable platform or tripod rather than handheld as in that video. Plus the camera would have to be stabilized and aligned with the leveling site.

I think about it, but would appreciate input or feedback, particularly from "horizon always at eye level" proponents.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 26, 2018, 07:07:58 AM
I confess I don't understand the horizon in a flat model. As I think I understand it, the FE "horizon" is a perceptual one (apparent) that occurs level to height of viewer (0° to the horizontal), but isn't a measurable distance. It depends on acuity (resolution) and obscuring factors in the air.

(http://oi67.tinypic.com/zlbw2e.jpg)

The horizon on a convex curved surface is a geometric point, calculated by height of viewer and radius of the curve, but it's always some angle below the horizontal, though appearing to be at horizontal for low values of h relative to r.

(http://oi66.tinypic.com/es9ohy.jpg)

If so, then I think that if you can demonstrate that the horizon drops below horizontal eye level with increasing height, it supports a curved surface. If the horizon appears consistently at the horizontal at all values of h, it would support the flat earth claim.

Does that make sense?

If so, the next step is to find agreement on how best to measure and document the horizon vs. "eye level" at different heights above the surface. I have some ideas, and I have easy access to viewpoints from sea level to 1500' with clear views to an ocean horizon, though catching a non-hazy day for a good horizon contrast is hit and miss this time of year.

I like the idea of a water level that's not cumbersome to tote on a hike, but I'd want it to be set up on a stable platform or tripod rather than handheld as in that video. Plus the camera would have to be stabilized and aligned with the leveling site.

I think about it, but would appreciate input or feedback, particularly from "horizon always at eye level" proponents.

This is something that's really easy to test. I'd like to see an acknowledgement that


I don't expect people to reject flat Earth altogether when this test is proposed, but I would hope that the "horizon rises to eye level" idea could at least be addressed. If the FE proponents are confident that the horizon does rise to eye level then they should be demanding that such experiments take place.

I'll state my own POV up front. I'm interested in the cognitive dissonance of the FE movement, and I'm reasonably confident that the items on the above list wouldn't be accepted by any FE proponents. If I'm wrong, then a test will be devised, the experiment performed, the results accepted and the FAQ on this site amended accordingly.

It should be something performable with some kind of levelling device, a camera, and a hillside overlooking the sea.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on April 26, 2018, 08:39:59 AM
On a globe the horizon is always below your eye level, because it i physically below your eye level and perspective doesn't not change physical relations between objects. Below is always below, above is always above, left is always left and right always right with respect to the optical axis defined by your eye and the point where you are looking at. Therefor, if you are looking parallel to the tangent line of the globe where you're standing, the horizon is always below.

On a flat earth there's no horizon in that sense, because the sky would be physically always above you, the ground always below you. They would only meet at infinity at the so-called vanishing point. But because no one can look that far under the atmospheric conditions of our earth, everything would be vanishing in diffusive blur far away...   
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on April 26, 2018, 10:18:32 AM
This is something that's really easy to test. I'd like to see an acknowledgement that

  • "The horizon is always at eye level" is a testable proposition.
  • Agreement on a test that can be readily carried out.
  • Acceptance that if the test disproves the proposition, that it should no longer be put forward.

I don't expect people to reject flat Earth altogether when this test is proposed, but I would hope that the "horizon rises to eye level" idea could at least be addressed. If the FE proponents are confident that the horizon does rise to eye level then they should be demanding that such experiments take place.

I'll state my own POV up front. I'm interested in the cognitive dissonance of the FE movement, and I'm reasonably confident that the items on the above list wouldn't be accepted by any FE proponents. If I'm wrong, then a test will be devised, the experiment performed, the results accepted and the FAQ on this site amended accordingly.

It should be something performable with some kind of levelling device, a camera, and a hillside overlooking the sea.

I do find this one particularly weird because you can think about horizon dip theoretically but then you can go and test this yourself. It can be measured.
3 different ways of doing this have been shown on here recently, they've all been rejected on spurious grounds. The real reason they've been rejected is that they don't show what the FE Dogma claims. As you say, cognitive dissonance.
Tom did outline a method of testing this which involved a camera looking across a tall building towards the horizon which actually would work in theory but there are two quite serious problems with that method
1) Buildings are, in general, not that tall and significant horizon dip can only be clearly seen at higher altitudes.
2) There is no way of accurately determining that the height of the building and the height of the camera are exactly the same.

This is where the experiment shown above wins because you can take the simple equipment with the water to any height and be sure that looking across the two tubes will be level. Tom's rejection of that was that it was hand held and therefore not that steady, but I took these stills which shows the result very clearly:

(https://image.ibb.co/i9H7Kn/horizondip.jpg)

It's quite hard to argue people who literally refuse to concede a point when it is demonstrated so clearly.
For his next trick, to misquote Douglas Adams, he'll claim black is white and get killed on the next zebra crossing.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 26, 2018, 11:49:24 AM

It's quite hard to argue people who literally refuse to concede a point when it is demonstrated so clearly.
For his next trick, to misquote Douglas Adams, he'll claim black is white and get killed on the next zebra crossing.

This is an example of just how things work in this kind of discussion. Clearly you need some kind of objective measure of level. Since it's generally known that water flows downhill, the u-tube with a coloured liquid is a good idea. It's not totally accurate, but it doesn't need to be. The point isn't to measure the drop to the horizon - it's to demonstrate that the drop to the horizon exists.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 27, 2018, 05:46:26 PM
Planning this out to see if it's worth the effort. I think a set up like that water rig is the best, though I'd like to set it on a sturdy tripod, as well having the camera on a tripod level with the sight line.

I'm thinking about the following locations (all San Diego county) with elevations:

Ocean Beach
32.750551, -117.252887
H=4ft
VH=12837ft
Angle=89.98°
Expected Dip=(00.02°)

Point Loma
32.703142, -117.249516
H=400ft
VH=129369ft
Angle=89.82°
Expected Dip=(00.18°)

Black Mountain Glider Launch
32.987933, -117.122248
H=1160ft
VH=220307ft
Angle=89.70°
Expected Dip=(00.30°)

Black Mountain Summit
32.981675, -117.116565
H=1376ft
VH=239943ft
Angle=89.67°
Expected Dip=(00.33°)

That's about the most elevation I can get locally and still keep a pretty sharp contrast to the horizon. I don't gain much altitude without going further inland but then horizon gets fuzzier.

At 1376' I only calculate a dip angle below horizontal of 0.33°

I don't really care about measuring the dip. Only whether or not it is detected. But that means making sure I have an accurate level sight line. The water level rig is great because then I don't have to worry about leveling two things. I just need to level the camera.

I played around with a 4' carpenters level on a tripod, using a plumb line/square, the bubble level on both the level and the tripod, (and yes, even my iphone, for what it's worth) to try to make it level, but who knows if it's +/- a degree from 90°?

Anyway, here's the shot:
(http://oi68.tinypic.com/2n7ip3a.jpg)

DLSR camera was not on a tripod.
I didn't get it lined up quite right. I wanted the centerline of the level to be horizontal but my camera elevation was little too high. But the perspective vanishing point is above the visible horizon. All of the photos were like this. None erred to at or below the horizon contrast point. At only 400', though, and a predicted "dip" of less than a quarter of the angular diameter of the sun, I'm not sure this is meaningful without a true level set of indices.

I'm just playing around right now. Trying to make a plan before I spend time building a leveling rig and making the hikes.

(The photo above without the annotation: http://oi65.tinypic.com/9hi0dk.jpg (http://oi65.tinypic.com/9hi0dk.jpg))
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on April 27, 2018, 11:43:40 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?

https://www.youtube.com/watch?v=NqOQ_BCtqUI (https://www.youtube.com/watch?v=NqOQ_BCtqUI)

Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?

The hand held camera's slight up down motion, in line with the black line of the water in the foreground affects the scene significantly in the far background, even if it is a pixel.

Everything needs to be perfectly leveled and aligned, and this water device is insufficient.

Furthermore, on a mountain or large hill, how do you know that the true horizon hasn't disappeared into an atmospheric fog that you can't see, thousands of miles away from you, and is squished beyond imperceptibility? This is clearly what happens when you get to high altitudes like from an international flight. The horizon is very foggy. What makes you think that the same is not true at lower altitudes, but the disappearance is more squished into the horizon by perspective?
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on April 28, 2018, 02:07:22 AM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?

https://www.youtube.com/watch?v=NqOQ_BCtqUI (https://www.youtube.com/watch?v=NqOQ_BCtqUI)

Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?

The hand held camera's slight up down motion, in line with the black line of the water in the foreground affects the scene significantly in the far background, even if it is a pixel.

Everything needs to be perfectly leveled and aligned, and this water device is insufficient.

Furthermore, on a mountain or large hill, how do you know that the true horizon hasn't disappeared into an atmospheric fog that you can't see, thousands of miles away from you, and is squished beyond imperceptibility? This is clearly what happens when you get to high altitudes like from an international flight. The horizon is very foggy. What makes you think that the same is not true at lower altitudes, but the disappearance is more squished into the horizon by perspective?
Tell me, why does the distance to a horizon over water increase with altitude then?
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 28, 2018, 03:19:50 AM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?

https://www.youtube.com/watch?v=NqOQ_BCtqUI (https://www.youtube.com/watch?v=NqOQ_BCtqUI)

Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?

The hand held camera's slight up down motion, in line with the black line of the water in the foreground affects the scene significantly in the far background, even if it is a pixel.

Everything needs to be perfectly leveled and aligned, and this water device is insufficient.

Furthermore, on a mountain or large hill, how do you know that the true horizon hasn't disappeared into an atmospheric fog that you can't see, thousands of miles away from you, and is squished beyond imperceptibility? This is clearly what happens when you get to high altitudes like from an international flight. The horizon is very foggy. What makes you think that the same is not true at lower altitudes, but the disappearance is more squished into the horizon by perspective?

In have dealt with this question and proved through measurements with a sextant (accurate and calibrated) that the arc of the sky is more than 180 degrees, by pretty much the same amount as is expected for the hieght of the observer.
What dont you understand about that Tom?
If the sky, from clear, sharp horizon, to the south, across the sky to a clear sharp horizon on the north is more than 180 degrees, then the bit below you is less, therefore the horizon is NOT rising to meet you.

I cannot really explain much clearer, and a young teenage child would likely understand that.
Title: Re: The Horizon is Always at Eye Level
Post by: SiDawg on April 28, 2018, 07:00:38 AM

Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?
That's the beauty of the two tubes... yes if you angle them "downhill" there will be a slight delay as liquid from one moves to the other, but given the size of the pipes, that's almost instantaneous. That's like saying the water in a bucket isn't level when you tip it... if you tip it quickly it might 'wobble' but it very quickly finds level.

The hand held camera's slight up down motion, in line with the black line of the water in the foreground affects the scene significantly in the far background, even if it is a pixel.

Everything needs to be perfectly leveled and aligned, and this water device is insufficient.
I agree it's a rough demonstration: but for some frames, he's actually misaligned so that the far tube water line is ABOVE the near level: so if the horizon is appearing below both, then that's even GREATER proof... if they were all level and on a flat earth (horizon and both tubes), then the horizon would've appeared ABOVE the second tube line.

Furthermore, on a mountain or large hill, how do you know that the true horizon hasn't disappeared into an atmospheric fog that you can't see, thousands of miles away from you, and is squished beyond imperceptibility? This is clearly what happens when you get to high altitudes like from an international flight. The horizon is very foggy. What makes you think that the same is not true at lower altitudes, but the disappearance is more squished into the horizon by perspective?
That's a fair call. I wish this guy had've run the experiment in a colder/clearer climate. The final distance especially shows huge atmospheric effects. The important thing to remember is that the world IS a globe, it is not flat, and you're looking for ways to justify your confirmation bias ;)
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 28, 2018, 11:01:32 AM
I wish this guy had've run the experiment in a colder/clearer climate. The final distance especially shows huge atmospheric effects. The important thing to remember is that the world IS a globe, it is not flat, and you're looking for ways to justify your confirmation bias ;)

An important point is that because the horizon as seen from a height is much further away, it's likely to be fuzzier, because there's more atmosphere in the way. Note that this effect only happens on a round Earth, because on a flat Earth, the horizon is an effect of... well, I'm not clear exactly what it's an effect of. If the flat Earth horizon is due to atmospheric distortion, then it should always be fuzzy. If it's due to "perspective" then who knows?

It should also be noted that even though the horizon is fuzzy, it's still perfectly possible to see that it is below eye level.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on April 28, 2018, 11:49:35 AM
Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?
:D

Wow. So you think that the water in the two connected tubes could be at different heights because "water flows down hill".
I think that's my new favourite Tom Bishop quote.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 28, 2018, 05:35:52 PM
Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?

The hand held camera's slight up down motion, in line with the black line of the water in the foreground affects the scene significantly in the far background, even if it is a pixel.

Everything needs to be perfectly leveled and aligned, and this water device is insufficient.

Furthermore, on a mountain or large hill, how do you know that the true horizon hasn't disappeared into an atmospheric fog that you can't see, thousands of miles away from you, and is squished beyond imperceptibility? This is clearly what happens when you get to high altitudes like from an international flight. The horizon is very foggy. What makes you think that the same is not true at lower altitudes, but the disappearance is more squished into the horizon by perspective?
On YouTube, there are examples of flat earth proponents using this technique to demonstrate that the horizon DOES rise to eye-level. And in the comments section, flat earth skeptics harshly discount the demo/test using many of these same critiques.

I think the principle is sound. It comes down to the execution. Anyone making a claim either way (horizon rises to eye-level or it dips below horizontal), should be able to explain why it is so and how it could be verified. How do you know it's true, one way or the other? The "dip" below horizontal on a globe the size of the earth is so small, you can't tell with just your Mk 1 mod 0 eyeball. . Testers for "flatness" and "globeness" both face the same challenges before they can claim their pet conclusion has been verified.

1. Yes, I think a clear horizon with contrast is critical.
2. Everything needs to be steady and stable. Handheld is no good, IMO. Camera should be on a tripod. Water leveler kept still and given a few moments to stabilize and then don't jostle it.
3. Everything does need to be level, but mainly it's the camera/eye level that's the key. The water will find its own level, assuming no bubble dams or vacuums. Lining up the two water level indices along the sightline of the camera/eye is the crux of the demo.

I'm thinking using the water level itself to level the camera:
(http://oi63.tinypic.com/1zfhmoi.jpg)

This demo isn't to measure the angle of declination. It's just to see if anyone with access to simple measuring tools can detect if any angle exists. It may be imperceptible close to MSL, but if in a flat earth the "horizon is always at eye level" then increasing elevation "h" should verify that claim since in globe geometry it won't.

If you're going to make the claim one way or the other, whether in support of flatness or curve, you should be able to back it up.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on April 28, 2018, 07:46:49 PM
Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?
:D

Wow. So you think that the water in the two connected tubes could be at different heights because "water flows down hill".
I think that's my new favourite Tom Bishop quote.

It does take some time for water to flow. It isn't instantaneously.

In the video you have provided, at the top of the mountain, he is just holding the water device in his hand, which appears to be wobbly, and a camera in his other hand.

The flow of the water is one concern. The other concern is that the camera is not perfectly level and that there is some room to where things appear "perfectly level".

In have dealt with this question and proved through measurements with a sextant (accurate and calibrated) that the arc of the sky is more than 180 degrees, by pretty much the same amount as is expected for the hieght of the observer.
What dont you understand about that Tom?
If the sky, from clear, sharp horizon, to the south, across the sky to a clear sharp horizon on the north is more than 180 degrees, then the bit below you is less, therefore the horizon is NOT rising to meet you.

I cannot really explain much clearer, and a young teenage child would likely understand that.

Surveying is always in error. Always. Every angle and vertical and position needs to be finely positioned. And even when it is to the best of our ability, it is still in error. There is also lens error, which is always present.

http://whistleralley.com/surveying/theoerror/

Quote
As any surveyor should understand, all measurements are in error. We try to minimize error and calculate reasonable tolerances, but error will always be there. Not occasionally; not frequently; always. In the interest of more accurate measurements, we look for better instruments and better procedures.

Also see Rowbotham's issues with measuring the horizon with devices that have lenses (http://www.sacred-texts.com/earth/za/za45.htm), as an example of device error.

An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 28, 2018, 08:30:48 PM
Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.
If it's that hard to verify (or refute), then maybe a claim of "horizon is always at eye-level" isn't one FET should definitively make.

The difference between flat and curved in the earth's case is less than 1° for heights above surface we've been talking about. You can't tell that from just looking. You have to measure somehow.

Is there any demonstration FET has relied on to verify that claim? Anything I can duplicate?
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on April 28, 2018, 08:41:10 PM
It does take some time for water to flow. It isn't instantaneously.
For a liquid that depends on the viscosity and water really isn't that viscous so it more or less is. It's close enough that you don't really have to give it any significant time to "settle".

Yes, it is all hand held although I'd say the result is pretty clear and I have provided the stills which show the result even more clearly.
And you have been shown two other methods of showing this, both of them gave the same result as this one.

But, as was said at the time, if you dispute the findings...do it yourself! This is an easily repeatable experiment.
You suggested an alternative experiment with two buildings. In theory that is equivalent but the problems with that are that buildings are, in general, not that high and it's only at significant altitude you see a decent horizon drop and it's next to impossible to be certain that the camera height and the building height are exactly the same. That's where the experiment with the two tubes of water wins, you can take the equipment to any height and, if they're connected, be sure that the water in the two tubes is the same

So...have a go. And if you do then agree that there is horizon dip then that doesn't mean you have to abandon belief in a flat earth, but you would maybe have to adjust your model accordingly. That's how pretty much all progress has been made. You lament the lack of funding and organisation in your movement but you don't need any funding to do this, the dude who made the original video just took it upon himself and did it one day. I tried to take a photo on a recent work trip when I was on a plane but I didn't have a window seat and it was a bit difficult. The horizon wasn't that clear either, there was quite a lot of cloud. I fly fairly regularly with work so will try again another time. Meanwhile, why not have a go yourself?
Title: Re: The Horizon is Always at Eye Level
Post by: inquisitive on April 28, 2018, 09:06:34 PM
Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?
:D

Wow. So you think that the water in the two connected tubes could be at different heights because "water flows down hill".
I think that's my new favourite Tom Bishop quote.

It does take some time for water to flow. It isn't instantaneously.

In the video you have provided, at the top of the mountain, he is just holding the water device in his hand, which appears to be wobbly, and a camera in his other hand.

The flow of the water is one concern. The other concern is that the camera is not perfectly level and that there is some room to where things appear "perfectly level".

In have dealt with this question and proved through measurements with a sextant (accurate and calibrated) that the arc of the sky is more than 180 degrees, by pretty much the same amount as is expected for the hieght of the observer.
What dont you understand about that Tom?
If the sky, from clear, sharp horizon, to the south, across the sky to a clear sharp horizon on the north is more than 180 degrees, then the bit below you is less, therefore the horizon is NOT rising to meet you.

I cannot really explain much clearer, and a young teenage child would likely understand that.

Surveying is always in error. Always. Every angle and vertical and position needs to be finely positioned. And even when it is to the best of our ability, it is still in error. There is also lens error, which is always present.

http://whistleralley.com/surveying/theoerror/

Quote
As any surveyor should understand, all measurements are in error. We try to minimize error and calculate reasonable tolerances, but error will always be there. Not occasionally; not frequently; always. In the interest of more accurate measurements, we look for better instruments and better procedures.

Also see Rowbotham's issues with measuring the horizon with devices that have lenses (http://www.sacred-texts.com/earth/za/za45.htm), as an example of device error.

An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.
What is the error quoted for equipment available today?
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 28, 2018, 10:07:23 PM
Water flows down hill.

So .... how does that effect the two linked columns of water? Are you suggesting the farther away one will settle to be lower than the nearer? You suggest that would lead to the sight line along the two pointing downward?

How do we know that water was perfectly leveled out at the point of the line ups?

You can see stationary water in both.

The hand held camera's slight up down motion, in line with the black line of the water in the foreground affects the scene significantly in the far background, even if it is a pixel.

Everything needs to be perfectly leveled and aligned, and this water device is insufficient.

Name a 'sufficient' device, then

Furthermore, on a mountain or large hill, how do you know that the true horizon hasn't disappeared into an atmospheric fog that you can't see, thousands of miles away from you, and is squished beyond imperceptibility? This is clearly what happens when you get to high altitudes like from an international flight. The horizon is very foggy. What makes you think that the same is not true at lower altitudes, but the disappearance is more squished into the horizon by perspective?

Surely such a fog would affect globe earthers and flat earthers equally, such that the flat earthers would also have their claim thrown into doubt?
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 28, 2018, 10:10:03 PM
An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.

So does that shed doubt on the flat-earthers' claim that the horizon always rises to eye-level, then, since all examples of illustrating this seem to also rely on hand-held cameras and off-the-cuff measures?

Or do you have access to better equipment than the globe-earthers? If so, what is it?
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on April 28, 2018, 10:26:21 PM
An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.

So does that shed doubt on the flat-earthers' claim that the horizon always rises to eye-level, then, since all examples of illustrating this seem to also rely on hand-held cameras and off-the-cuff measures?

Or do you have access to better equipment than the globe-earthers? If so, what is it?

Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.
Title: Re: The Horizon is Always at Eye Level
Post by: inquisitive on April 28, 2018, 10:32:22 PM
An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.

So does that shed doubt on the flat-earthers' claim that the horizon always rises to eye-level, then, since all examples of illustrating this seem to also rely on hand-held cameras and off-the-cuff measures?

Or do you have access to better equipment than the globe-earthers? If so, what is it?

Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.
And you have repeated this?  How would you know the height of the ground? How far apart?

You have still not tested anything. Sad...
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 28, 2018, 11:17:39 PM
... involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

Do you assert that this method is ... better? more accurate? something else? ... than the U-shaped pipes with coloured water?

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.

How did R determine his markers were at the known height and distances without "calibration"
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 28, 2018, 11:21:15 PM
An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.

So does that shed doubt on the flat-earthers' claim that the horizon always rises to eye-level, then, since all examples of illustrating this seem to also rely on hand-held cameras and off-the-cuff measures?

Or do you have access to better equipment than the globe-earthers? If so, what is it?

Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.

How on Earth do you verify that two markers are at exactly the same height? The only way to verify that two markers are at the same height is by calibrating devices and careful levelling.

I suspect that Rowbotham levelled his two markers by lining them up with the horizon, and then used them to verify that they were in line with the horizon.

This is another one of these situations where one starts to think that one is being made a fool of, and that this "Flat Earth" joke is just being pushed as far as it can go.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 28, 2018, 11:22:38 PM
... involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

Do you assert that this method is ... better? more accurate? something else? ... than the U-shaped pipes with coloured water?

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.

How did R determine his markers were at the known height and distances without "calibration"

See my guess - he lined them up with the horizon. Or he found a patch of ground that looked sort of level and stuck 'em in.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on April 28, 2018, 11:27:41 PM
An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.

So does that shed doubt on the flat-earthers' claim that the horizon always rises to eye-level, then, since all examples of illustrating this seem to also rely on hand-held cameras and off-the-cuff measures?

Or do you have access to better equipment than the globe-earthers? If so, what is it?

Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.

How on Earth do you verify that two markers are at exactly the same height? The only way to verify that two markers are at the same height is by calibrating devices and careful levelling.

I suspect that Rowbotham levelled his two markers by lining them up with the horizon, and then used them to verify that they were in line with the horizon.

This is another one of these situations where one starts to think that one is being made a fool of, and that this "Flat Earth" joke is just being pushed as far as it can go.

Why not read the book to find out?

See my guess - he lined them up with the horizon. Or he found a patch of ground that looked sort of level and stuck 'em in.

Incorrect. The markers are often natural in nature, that are a known altitude. There are numerous horizon experiments in Earth Not a Globe. Read the book.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 28, 2018, 11:34:51 PM
Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.
I thought he used a clinometer and recorded observations from different floors of a seaside building.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 28, 2018, 11:39:52 PM
Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.
I thought he used a clinometer and recorded observations from different floors of a seaside building.
Experiment 15
http://www.sacred-texts.com/earth/za/za20.htm (http://www.sacred-texts.com/earth/za/za20.htm)

There are numerous such horizon experiments in the book.
Several experiments, but this was the only one I remember (and currently skimming through is the only one I'm finding) dealing with horizon rising to eye-level.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 28, 2018, 11:46:28 PM
Tangential horizon

http://www.sacred-texts.com/earth/za/za45.htm (http://www.sacred-texts.com/earth/za/za45.htm)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 29, 2018, 12:01:39 AM
Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.
I thought he used a clinometer and recorded observations from different floors of a seaside building.

Experiment 15
http://www.sacred-texts.com/earth/za/za20.htm (http://www.sacred-texts.com/earth/za/za20.htm)

This is essentially the kind of demonstration both globe and flat earth advocates are attempting, and what I've been planning.

If this is inherently flawed, Experiment 15 ought to be discounted.

I'm not finding the one you describe, but you can point me to it, I'd appreciate it.
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on April 29, 2018, 12:28:51 AM
Incorrect. The markers are often natural in nature, that are a known altitude.
And how do you think that we determine those altitudes? You can either (a) accept that the altitude measurements are accurate, and therefore that Tontogary's experiment is accurate, or (b) concede that Rowbotham's experiments had some inaccuracies and lose one of your biggest "proofs" that the Earth is flat. Oh yeah, there's a (c) for explaining why Rowbotham's experiments are accurate but not Tontogary's, but I have no faith that you will actually do that in any sane way.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 29, 2018, 01:35:02 AM
An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.

So does that shed doubt on the flat-earthers' claim that the horizon always rises to eye-level, then, since all examples of illustrating this seem to also rely on hand-held cameras and off-the-cuff measures?

Or do you have access to better equipment than the globe-earthers? If so, what is it?

Read how Rowbotham determined how the horizon was at eye level. He didn't use a theodolite. It involved setting up markers of a known height a far distance apart from each other and placing your eye at the level of the first marker and seeing that the horizon was lined up with it.

An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.

Then he was in error.
As you are fond of claiming all surveying methods are in error. He could not have ensured the markers of being EXACTLY the same hieght, on an EXACTLY level ground. How could he have measured the height to be absolute? The experiment therefore it must be discounted as in error. There is no calculations, method, or verification of his experiment, other than his statement that he did this and that.

As for his experiment in chapter II experiment 15, are we to believe what is written as proof?
He took a “clinometer” no mention of what type or how its calibrated, to different floor in a hotel, and saw the horizon was the same. (Or virtually the same) Which might well have been a plumb bob with a set square attached (as he used in other “experiments”) and eyeballed the horizon.


However have you ever seen the “Grand Hotel” in Brighton? It is not that “grand” and has a total of 6 stores. Now lets be generous and and say it has a height of 10 feet (3M) between floors. By the time he gets to the highest room, he is about 20 meters above the lowest floor, and the dip of the horizon when eyeballing it is 7.9 minutes of arc. Pretty much guesswork if you are eyeballing it.
This experiment is in error. As all surveys are in error according to you.
Therefore one cannot trust EnaG, as it is full of errors.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 29, 2018, 02:03:32 AM
Water flows down hill. How do we know that water was perfectly leveled out at the point of the line ups?
:D

Wow. So you think that the water in the two connected tubes could be at different heights because "water flows down hill".
I think that's my new favourite Tom Bishop quote.

It does take some time for water to flow. It isn't instantaneously.

In the video you have provided, at the top of the mountain, he is just holding the water device in his hand, which appears to be wobbly, and a camera in his other hand.

The flow of the water is one concern. The other concern is that the camera is not perfectly level and that there is some room to where things appear "perfectly level".

In have dealt with this question and proved through measurements with a sextant (accurate and calibrated) that the arc of the sky is more than 180 degrees, by pretty much the same amount as is expected for the hieght of the observer.
What dont you understand about that Tom?
If the sky, from clear, sharp horizon, to the south, across the sky to a clear sharp horizon on the north is more than 180 degrees, then the bit below you is less, therefore the horizon is NOT rising to meet you.

I cannot really explain much clearer, and a young teenage child would likely understand that.

Surveying is always in error. Always. Every angle and vertical and position needs to be finely positioned. And even when it is to the best of our ability, it is still in error. There is also lens error, which is always present.

Also see Rowbotham's issues with measuring the horizon with devices that have lenses (http://www.sacred-texts.com/earth/za/za45.htm), as an example of device error.

An off-the-cuff or hand-held surveying demo is not going to cut it. The tolerances are extremely sensitive, and there are many ways it can be wrong. Slight angles and positions and incorrect device calibration will create different results.

Once you have something that is actually irrefutable to FET, let us know, so we can shut down this website.

Ok then lets deal with your above assumptions.

Let’s have a look at EnaG shall we?
If he asserts that all instruments with a lens are in error, then we can discount the experiments in chapter 2 almost in their entirety, he uses a telescope in experiments 1,2,5,and 12,  and a theodolite in experiments 3,4,8,11, and 14. Therefore hits chapter where he says he PROVES the earth is flat, can be pretty much discounted.
He uses sextant observations from 3rd hand accounts in other chapters, as well as theodolites and telescopes and other even cruder instruments such as plumb bobs with a set square attached and steel tubes so called mounted vertically. All very “Herath Robinson” esq you must admit, therefore the entire book and theory can be thrown out as in error, and not accurate!

As for my sextant observations, We use a modern instrument, which has been refined over hundreds of years (the optics etc are far superior to anything available in Victorian times) and i have shown how we calibrate for instrument error, using known objects and we can cross check and verify our instrument error, and apply it to our readings.
EnaG does not show any of that.

I am able to show that my readings are to within an accuracy of 0.1 minute of arc, i have a manufacturerers certificate to show that it can measure to that accuracy, and I can show my method, and i can verify my results to be within an acceptable margin of error.

The thing here is that Tom just says “all surveying is in error” but he wont tell you what the acceptable margin of error is!

Even if i could only measure to 1 minute of arc, then my previous experiment/observation to measure the arc of the sky from horizon to horizon gave an arc of 180 degrees and 32 minutes rounded up to the nearest minute, it still means that the arc below my feet measured 179 degrees and 28 minutes, (unless Tom can prove there are more than 360 degrees in a circle?)
Therefore the difference is more than a whole degree. If i couldn’t measure that accurately, there is no way i could fix a ships position, and i have done that thousands of times. My record of still being alive, and never having been on a ship when it went aground will testify to that.

So Tom what are you still doing trying to deny a measurement that proves the horizon does not rise to eye level by making general sweeping (misleading) statements to try to prop up your argument.

I guess if you did accept my Zetetic experiment, and observations, you would as you say, have to close down this site as it is clearly busted.


Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on April 29, 2018, 05:42:01 AM
Ok then lets deal with your above assumptions.

Let’s have a look at EnaG shall we?
If he asserts that all instruments with a lens are in error, then we can discount the experiments in chapter 2 almost in their entirety, he uses a telescope in experiments 1,2,5,and 12,  and a theodolite in experiments 3,4,8,11, and 14. Therefore hits chapter where he says he PROVES the earth is flat, can be pretty much discounted.

The experiments are specifically designed so that the lens error that was described wouldn't matter.

Quote
As for my sextant observations, We use a modern instrument, which has been refined over hundreds of years (the optics etc are far superior to anything available in Victorian times) and i have shown how we calibrate for instrument error, using known objects and we can cross check and verify our instrument error, and apply it to our readings.
EnaG does not show any of that.

I am able to show that my readings are to within an accuracy of 0.1 minute of arc, i have a manufacturerers certificate to show that it can measure to that accuracy, and I can show my method, and i can verify my results to be within an acceptable margin of error.

The thing here is that Tom just says “all surveying is in error” but he wont tell you what the acceptable margin of error is!

Even if i could only measure to 1 minute of arc, then my previous experiment/observation to measure the arc of the sky from horizon to horizon gave an arc of 180 degrees and 32 minutes rounded up to the nearest minute, it still means that the arc below my feet measured 179 degrees and 28 minutes, (unless Tom can prove there are more than 360 degrees in a circle?)
Therefore the difference is more than a whole degree. If i couldn’t measure that accurately, there is no way i could fix a ships position, and i have done that thousands of times. My record of still being alive, and never having been on a ship when it went aground will testify to that.

So Tom what are you still doing trying to deny a measurement that proves the horizon does not rise to eye level by making general sweeping (misleading) statements to try to prop up your argument.

I guess if you did accept my Zetetic experiment, and observations, you would as you say, have to close down this site as it is clearly busted.

We have no idea about all of the details of your experiment. What brand of tools and what methods were done to ensure accuracy? What if the horizon was slightly hazy?

Come up with something that is truly irrefutable.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 29, 2018, 06:48:25 AM
Ok then lets deal with your above assumptions.

Let’s have a look at EnaG shall we?
If he asserts that all instruments with a lens are in error, then we can discount the experiments in chapter 2 almost in their entirety, he uses a telescope in experiments 1,2,5,and 12,  and a theodolite in experiments 3,4,8,11, and 14. Therefore hits chapter where he says he PROVES the earth is flat, can be pretty much discounted.

The experiments are specifically designed so that the lens error that was described wouldn't matter.

What a load of rubbish.

Your claim please show where in his methodology he shows that lens error is excluded by the design of the experiments? You cant cos he didnt.

I on the other hand have the manufacturers certificate of the instrument to show there is no “lens” error as you call it, (which is not what its called, but then if you actually knew anything about the subject you would know that!)
I described my measurements in another thread, started by myself, and your only contribution was to say that surveying is in error!
Search “horizon rising to eye level and a foolproof way to measure it”
I clearly describe my method, and accuracy of the instrument, and the way the result is cross checked.

The horizon was clear, and certainly not in error by a suns diameter!
A slightly hazy horizon would make a potential .2 or .3 minute of arc error, not by half a degree or more.
Your rather amateurish comments shows your ignorance of the use of a sextant, or any other accurate measuring device.
The measurements were taken off shore in N.W australia, which if anyone who has been there will confirm is a very dry place, so humidity and other sources of haze were not a factor. As it was at mer pass, the horizon was well lit and sharp.


I have provided you with much more proof than EnaG ever did, where he just relies upon dodgy third hand reports, bits of string with a set square attached, and a “telescope” or “theodolite” with no manufacturer or accuracy or way of verifying his  (even if they were his own and most likely someone else’s) observations.

You are rapil]day running out of viable excuses Tom.


Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on April 29, 2018, 07:36:53 AM
Come up with something that is truly irrefutable.
But that's a silly challenge.
Rowbowtham's "experiments" are him just saying "this is what I did and this is what I saw". Case closed, no further questions your honour!
But when you're shown 3 different experiments which all give the same results, two of which you've been provided video proof of the results, you dismiss them because they don't show what you want them to show.

So, rather than us wasting any more time doing experiments which we know you will dismiss in some way, you do an experiment.
You're an empiricist, right? You're writing a chapter on "the importance of empiricism".
Well go and take some empirical measurements for us to review.
We have shown theoretically that there should be horizon dip and proven it experimentally in 3 different ways which all give the same result.
Your claim is that the horizon always rises to eye level and that the experiments are in error.
OK. Do an experiment then and let's see your evidence.

Your best attempt so far is some YouTube video where some bloke is on the 7th story of a building near the shore which is far too close to sea level to see much dip.
You've been going on about calibration and you show us a video where there is no way of determining with any accuracy that the camera and building roof are at the same height. Are you serious?!

Maybe you are just here for a laugh and you just enjoy trying to defend the indefensible. FYI, it makes you look ridiculous.
But if you are serious about this then devise and do an experiment. The water tubes one is my suggestion because it's cheap equipment which can be taken to any altitude. But if you want to devise your own then that's fine too. I look forward to the results.
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 29, 2018, 07:53:45 AM
We have no idea about all of the details of your experiment. What brand of tools and what methods were done to ensure accuracy?

We have no idea about details of experiments, info on brand of tools and methods in ENaG, beyond the word 'clinometer'.
Title: Re: The Horizon is Always at Eye Level
Post by: Macarios on April 29, 2018, 07:37:04 PM
An experiment of this sort is far better than one which relies on calibrating devices and careful leveling.

Yes, careful leveling water must be very delicate task. :)

Could you, please, tell us how static water "flows downhill"?

If "leveling water is so hard", how can FE movement rely on "water is always level"?
It is not something that I invented right now and we all know that.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 29, 2018, 10:12:49 PM
We have no idea about all of the details of your experiment. What brand of tools and what methods were done to ensure accuracy?

We have no idea about details of experiments, info on brand of tools and methods in ENaG, beyond the word 'clinometer'.

If I'm not mistaken, the measurements were taken from different floors of a building. No measurable difference could be expected.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on April 29, 2018, 10:16:52 PM
Ok then lets deal with your above assumptions.

Let’s have a look at EnaG shall we?
If he asserts that all instruments with a lens are in error, then we can discount the experiments in chapter 2 almost in their entirety, he uses a telescope in experiments 1,2,5,and 12,  and a theodolite in experiments 3,4,8,11, and 14. Therefore hits chapter where he says he PROVES the earth is flat, can be pretty much discounted.

The experiments are specifically designed so that the lens error that was described wouldn't matter.

What a load of rubbish.

Your claim please show where in his methodology he shows that lens error is excluded by the design of the experiments? You cant cos he didnt.

In the Theodolite chapter (http://www.sacred-texts.com/earth/za/za45.htm) Rowotham speaks about the Wallace-Hampden Wager experiment and points out the flaw, and further asserts that his experiments were designed so that the flaw did not matter.
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 29, 2018, 10:22:56 PM
In the Theodolite chapter (http://www.sacred-texts.com/earth/za/za45.htm) Rowotham speaks about the Wallace-Hampden Wager experiment and points out the flaw, and further asserts that his experiments were designed so that the flaw did not matter.

Were you there to verify this, though?

(For you assert in another thread that anyone claiming SpaceX's footage to be genuine should provide witnesses below the flight path to witness the cloud patterns....)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 29, 2018, 10:31:15 PM
Ok then lets deal with your above assumptions.

Let’s have a look at EnaG shall we?
If he asserts that all instruments with a lens are in error, then we can discount the experiments in chapter 2 almost in their entirety, he uses a telescope in experiments 1,2,5,and 12,  and a theodolite in experiments 3,4,8,11, and 14. Therefore hits chapter where he says he PROVES the earth is flat, can be pretty much discounted.

The experiments are specifically designed so that the lens error that was described wouldn't matter.

What a load of rubbish.

Your claim please show where in his methodology he shows that lens error is excluded by the design of the experiments? You cant cos he didnt.

In the Theodolite chapter (http://www.sacred-texts.com/earth/za/za45.htm) Rowotham speaks about the Wallace-Hampden Wager experiment and points out the flaw, and further asserts that his experiments were designed so that the flaw did not matter.

No he does not show how his experiments using theodolites,  telescopes,  and clinometers were designed so that refraction, or “lens error” did not occur.
Sorry, your claim is still not proved.
YOUR claim, You prove it.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on April 29, 2018, 10:35:10 PM
Ok then lets deal with your above assumptions.

Let’s have a look at EnaG shall we?
If he asserts that all instruments with a lens are in error, then we can discount the experiments in chapter 2 almost in their entirety, he uses a telescope in experiments 1,2,5,and 12,  and a theodolite in experiments 3,4,8,11, and 14. Therefore hits chapter where he says he PROVES the earth is flat, can be pretty much discounted.

The experiments are specifically designed so that the lens error that was described wouldn't matter.

What a load of rubbish.

Your claim please show where in his methodology he shows that lens error is excluded by the design of the experiments? You cant cos he didnt.

In the Theodolite chapter (http://www.sacred-texts.com/earth/za/za45.htm) Rowotham speaks about the Wallace-Hampden Wager experiment and points out the flaw, and further asserts that his experiments were designed so that the flaw did not matter.

No he does not show how his experiments using theodolites,  telescopes,  and clinometers were designed so that refraction, or “lens error” did not occur.
Sorry, your claim is still not proved.
YOUR claim, You prove it.

Just look at his experiments. He's not trying to carefully level the theodolite or telescope with the center of a crosshair. He is merely using it as a magnification tool to see bodies that should be lined up when viewed, or is otherwise is just looking for the appearance or disappearance of boats and lighthouses into the horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 29, 2018, 10:50:08 PM
Just look at his experiments.

but elsewhere ...

If you are claiming something about lasers bounced off of satellites, you need to demonstrate that such a thing was done, and show the data showing that it lines up with what you believe a satellite to be. You need to show your work. A lot of it.
Show. Not tell. Not assume.
Your claim. Your burden.

"Just look at his experiments." doesn't cut it, Tom.

You need to demonstrate that such a thing was done, and show the data .... You need to show your work. A lot of it. Show. Not tell. Not assume. Your claim. Your burden.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 29, 2018, 10:52:05 PM
Just look at his experiments. He's not trying to carefully level the theodolite or telescope with the center of a crosshair. He is merely using it as a magnification tool to see bodies that should be lined up when viewed, or is otherwise is just looking for the appearance or disappearance of boats and lighthouses into the horizon.
Then there should be no objection to this set up for determining if the horizon always rises to the horizontal level of the eye:
(http://oi63.tinypic.com/1zfhmoi.jpg)

Especially compared with Rowbotham's Experiment 15.

If you have any further details on Rowbotham's "well-constructed" clinometer or what method he used to ensure "level", let me know. My intent is not just to report that I used an instrument, leveled it, and was able to verify that the horizon does or doesn't always at eye-level. I hope to provide a visual artifact to record my results, and describe my method well enough so that anyone else could go out and either duplicate or refute my results.

I see no questioning of Rowbotham's anecdotal account. But I do see you challenging those attempting who've tried to observe what Rowbotham claims, but coming up with a contrary result. If criticisms of the contrary attempts are valid, then they're valid for Rowbotham as well.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 29, 2018, 11:46:42 PM
Ok then lets deal with your above assumptions.

Let’s have a look at EnaG shall we?
If he asserts that all instruments with a lens are in error, then we can discount the experiments in chapter 2 almost in their entirety, he uses a telescope in experiments 1,2,5,and 12,  and a theodolite in experiments 3,4,8,11, and 14. Therefore hits chapter where he says he PROVES the earth is flat, can be pretty much discounted.

The experiments are specifically designed so that the lens error that was described wouldn't matter.

What a load of rubbish.

Your claim please show where in his methodology he shows that lens error is excluded by the design of the experiments? You cant cos he didnt.

In the Theodolite chapter (http://www.sacred-texts.com/earth/za/za45.htm) Rowotham speaks about the Wallace-Hampden Wager experiment and points out the flaw, and further asserts that his experiments were designed so that the flaw did not matter.

No he does not show how his experiments using theodolites,  telescopes,  and clinometers were designed so that refraction, or “lens error” did not occur.
Sorry, your claim is still not proved.
YOUR claim, You prove it.

Just look at his experiments. He's not trying to carefully level the theodolite or telescope with the center of a crosshair. He is merely using it as a magnification tool to see bodies that should be lined up when viewed, or is otherwise is just looking for the appearance or disappearance of boats and lighthouses into the horizon.

I have looked at his experiments, and almost none of them explain how the idea of refraction, or instrument error, or “lens error” are able to be discounted. Imperfections within a lens will make the image distorted. Levelling with a spirit level is the method used on many of his experiments, which is the very thing you are arguing against in the water tube experiment, claiming water flows down hill! A spirit level uses exactly the same principle as the water tube experiment, so you should have no objection.

Finally as to the accuracy of my equipment i attach 2 images, one the manufacturers certificate showing there are NO errors in the equipment across the range of use, and the other showing the serial number of the equipment.
I am sure you wont be satisfied, but it is a hell of a lot more than EnaG ever showed.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 29, 2018, 11:58:06 PM
And more pics. A better one of the certificate, and one taken a few days ago, trying to see if i could take a picture of the image you see in the sextant, however as they are designed to be used for navigation, not teaching, then they dont have a Wi-fi link to a phone or other data device, so i cannot use it to show exactly how to use the instrument.

It should suffice though, that i have a sextant that has no errors, with the serial number printed on it, and the certificate to match.

I also have a professional qualification which PROVES i know how to use it.

Rowbotham never gave any credentials, or details of his instruments, or did he ever show he was qualified or trained in their use.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 30, 2018, 04:55:00 AM
Nice.

I'm going low tech.

(http://oi64.tinypic.com/sgpo4j.jpg)

1. 3 rebar staked in-line at some distance x apart (x yet to be determined)
2. Leveling rig of clamped to rebar, one reservoir on each stake (two for sighting and 1 additional for leveling camera)
3. Fill with dyed water with some dish soap added.
4. Run twin from each rebar at level line; (double check with hanging line level)
5. Set camera on tripod and align with level line and sight line.

Sharp contrast of the horizon is a prerequisite.

Recommendations? Critiques?
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 30, 2018, 10:03:08 AM
Nice.

I'm going low tech.

(http://oi64.tinypic.com/sgpo4j.jpg)

1. 3 rebar staked in-line at some distance x apart (x yet to be determined)
2. Leveling rig of clamped to rebar, one reservoir on each stake (two for sighting and 1 additional for leveling camera)
3. Fill with dyed water with some dish soap added.
4. Run twin from each rebar at level line; (double check with hanging line level)
5. Set camera on tripod and align with level line and sight line.

Sharp contrast of the horizon is a prerequisite.

Recommendations? Critiques?

I assume that there will be a general welcome for this experiment from the FE community, because it offers the opportunity to have a major theory confirmed. Perhaps a representative could inspect the equipment and observe it taking place.

I'm kidding, of course. There's something in the back of the mind of most people holding irrational beliefs than knows that they shouldn't be exposed to rebuttal. This experiment will be derided in advance, in favour of Rowbotham's objectively bad experiment with inconclusive results from which conclusions were drawn.
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on April 30, 2018, 02:31:38 PM
It strikes me that the more interconnected tubes there are, the more chances that an unfriendly Team Hoaxer will assert;

"The water's flowing too slowly"
"The tubes are restricting the water flow"

and such ...  so;

Take a clear plastic lid or tray, such as this one, turned other way up;

(http://www.simon-catering-disposables.co.uk/Files/57122/Img/17/large-rectangle-sandwich-platter.jpg)

place on a reasonably flat surface, and fill with coloured water. The water will find its own level, and give a long edge to sight along. No issues/concerns over water flow.

Alternatively, take a clear plastic bag, part-fill with coloured water, and place on absolutely anything. The water, again, will find its own level, and a sighting can be taken along the top of the water's surface.

(https://ae01.alicdn.com/kf/HTB1kwNqQpXXXXbDXXXXq6xXFXXXm/10L-Collapsible-Foldable-Water-Bag-Container-Clear-Drink-Water-Storage-Bucket-Lifting-Bag-Hydration-Bladder-Outdoor.jpg_640x640.jpg)

(https://s-media-cache-ak0.pinimg.com/originals/e8/32/ba/e832ba718e9aba67d9f9906ef72be0ce.jpg)

(https://ae01.alicdn.com/kf/HTB1owx3SXXXXXXcXpXXq6xXFXXXB/3L-Collapsible-Water-Bag-Outdoor-Camping-Lightweight-Bucket-Tasteless-Clear-Water-Bag-100pcs-lot-Free-shipping.jpg_640x640.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on April 30, 2018, 03:05:19 PM
Very good.

It strikes me that with the last container, if there were a few gentlemen around you would not need to carry any liquid up the hill either............
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on April 30, 2018, 03:24:40 PM
The fundamental problem here is the FE belief is not based on evidence, it is despite the evidence.
They say they rely on empirical measurements but they don't, or rather they dismiss any empirical evidence which doesn't fit with their world view.
Witness how Tom tried all kinds of things to discredit the laser and boat experiment before finally understanding it...and declaring it fraudulent anyway despite none of the objections standing up to scrutiny.
And now he's been shown 3 different ways of showing horizon dip which all give the same result - but it's a result he doesn't want so he dismisses all of them on spurious grounds.

The only solution is for him to do some experiments himself to demonstrate his claims. We can do them all day - and people have - and he will dismiss all of them if they don't show what he wants. He claims to be an empiricist but he refuses to do any empirical measurements. Funny that. The only hint of him doing anything along these lines is the "Bishop Experiment" which he has no documentation of and he's pretty clearly lying about.

The mindset is based on this Wiki page which has been deleted, I don't know why as it perfectly describes the prevailing FE mindset on here:

Quote
P1) If personally unverifiable evidence contradicts an obvious truth then the evidence is fabricated
P2) The Flat Earth is an obvious truth

(My emphasis). So we are wasting our time. Tom can't personally verify the results of our experiments and he refuses to do so himself.
Checkmate.
He demands "irrefutable evidence" but that doesn't exist. You can refute any evidence if you're bloody minded enough.
As I said some time ago, you can do this about anything:

"I don't believe kangaroos exist".
"What?! Here's a Wiki page about them."
"Cool. Here's a Wiki page about dragons, do they exist too?"
"Here's a video of a kangaroo!"
"That's fake. Have you heard of CGI?"
"Right. We're at a zoo. Look. There's a kangaroo!"
"Looks like animatronic to me..."

And so on. It's ridiculous, of course, but if you're only interested in sticking to your guns come what may then you can dismiss anything, even if the dismissals become increasingly stupid.

Which leaves me with the thought that he's just here for fun, enjoys trying to debate from indefensible positions and doesn't believe any of this.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 30, 2018, 06:11:17 PM
If Sam Rowbotham's method was acceptable, we should be able to replicate it, and for elevations quite higher than the top floor of the Grand Brighton.

I like the idea of a single container, but I don't want to be lugging a lot of water up the trails to my planned viewing spots (or depending on "donations" from other hikers ;->).
But a simple pyrex dish could serve as a kind of mini "infinity pool" and would take minimal set up. I might do that alongside the tube hydrostatic leveler, just to provide a double check.

There's an estate on a 2000' peak just 7 miles from the ocean that sold at auction not too long ago, giving the public some video and photo of the mansion and grounds. It has a long infinity pool pointed directly toward the western horizon. What a great setting that would be for a "horizon rises to eye level" proof demonstration:
(http://oi68.tinypic.com/vgrija.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 30, 2018, 06:15:18 PM
The fundamental problem here is the FE belief is not based on evidence, it is despite the evidence.
They say they rely on empirical measurements but they don't, or rather they dismiss any empirical evidence which doesn't fit with their world view.
Witness how Tom tried all kinds of things to discredit the laser and boat experiment before finally understanding it...and declaring it fraudulent anyway despite none of the objections standing up to scrutiny.
And now he's been shown 3 different ways of showing horizon dip which all give the same result - but it's a result he doesn't want so he dismisses all of them on spurious grounds.

The only solution is for him to do some experiments himself to demonstrate his claims. We can do them all day - and people have - and he will dismiss all of them if they don't show what he wants. He claims to be an empiricist but he refuses to do any empirical measurements. Funny that. The only hint of him doing anything along these lines is the "Bishop Experiment" which he has no documentation of and he's pretty clearly lying about.

The mindset is based on this Wiki page which has been deleted, I don't know why as it perfectly describes the prevailing FE mindset on here:

Quote
P1) If personally unverifiable evidence contradicts an obvious truth then the evidence is fabricated
P2) The Flat Earth is an obvious truth

(My emphasis). So we are wasting our time. Tom can't personally verify the results of our experiments and he refuses to do so himself.
Checkmate.
He demands "irrefutable evidence" but that doesn't exist. You can refute any evidence if you're bloody minded enough.
As I said some time ago, you can do this about anything:

"I don't believe kangaroos exist".
"What?! Here's a Wiki page about them."
"Cool. Here's a Wiki page about dragons, do they exist too?"
"Here's a video of a kangaroo!"
"That's fake. Have you heard of CGI?"
"Right. We're at a zoo. Look. There's a kangaroo!"
"Looks like animatronic to me..."

And so on. It's ridiculous, of course, but if you're only interested in sticking to your guns come what may then you can dismiss anything, even if the dismissals become increasingly stupid.

Which leaves me with the thought that he's just here for fun, enjoys trying to debate from indefensible positions and doesn't believe any of this.

This is a particularly interesting one because it's a simple claim that can be rebutted very simply. It's not possible to rationally deny it. When you're up a mountain looking out to sea, the horizon is not at eye level. There's no sensible argument to refute this. We've shown that it's true beyond any reasonable doubt, and anyone who does the same test will find the same thing.

So at this stage, the interest is psychological. How fixed is the idea so that the denial is persisted with in spite of any evidence?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on April 30, 2018, 06:42:54 PM
There's an estate on a 2000' peak just 7 miles from the ocean that sold at auction not too long ago, giving the public some video and photo of the mansion and grounds. It has a long infinity pool pointed directly toward the western horizon. What a great setting that would be for a "horizon rises to eye level" proof demonstration:
(http://oi68.tinypic.com/vgrija.jpg)
Same pool, but with better images, and from a great vantage point.

(http://oi66.tinypic.com/21kxv9u.jpg)

Now with 1px perspective lines (black) and horizon (white)

(http://oi64.tinypic.com/156r9xx.jpg)

Camera leveling won't change the perspective lines. If the architecture isn't square and/or the pool is actually titled up (so that water flows away from the infinity edge), then they shouldn't converge to a perspective vanishing point above the horizon, IF it's true that the horizon rises to eye-level.

Unless I'm interpreting this incorrectly.

I'm not using it as proof of anything. Just a hint of what we might expect the results to be of a controlled observation.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on April 30, 2018, 11:08:11 PM
There's an estate on a 2000' peak just 7 miles from the ocean that sold at auction not too long ago, giving the public some video and photo of the mansion and grounds. It has a long infinity pool pointed directly toward the western horizon. What a great setting that would be for a "horizon rises to eye level" proof demonstration:
(http://oi68.tinypic.com/vgrija.jpg)
Same pool, but with better images, and from a great vantage point.

(http://oi66.tinypic.com/21kxv9u.jpg)

Now with 1px perspective lines (black) and horizon (white)

(http://oi64.tinypic.com/156r9xx.jpg)

Camera leveling won't change the perspective lines. If the architecture isn't square and/or the pool is actually titled up (so that water flows away from the infinity edge), then they shouldn't converge to a perspective vanishing point above the horizon, IF it's true that the horizon rises to eye-level.

Unless I'm interpreting this incorrectly.

I'm not using it as proof of anything. Just a hint of what we might expect the results to be of a controlled observation.

That's pretty conclusive, but it would be nice if you could get a sunset in the same picture. A fake sunset, of course!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 01, 2018, 07:09:58 AM
That's pretty conclusive, but it would be nice if you could get a sunset in the same picture. A fake sunset, of course!
Not a fan of the design of that mansion, but I would love have access to that infinity pool sight line on a clear evening at sunset with a sharp horizon.

Checking out the direction of that pool, it looks like the sun would set right down the centerline in late February or March. Not sure of the exact azimuth that pool is aimed at, but makes me wonder if it lines up with the equinox sunset.

Another photo, from further back. I drew in lines of perspective from three planes, based on the parallel lines of edges I could find. The merge at a  vanishing point on a line above the horizon. Is this a valid analysis of perspective that could demonstrate the horizon doesn't rise to "eye level?"

(http://oi64.tinypic.com/2pshws5.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 01, 2018, 07:20:32 AM
Checking out the direction of that pool, it looks like the sun would set right down the centerline in late February or March. Not sure of the exact azimuth that pool is aimed at, but makes me wonder if it lines up with the equinox sunset.
Nope. It's about a month off. Sun sets right down the chute on February 20th and October 20th; not the equinoxes. Oh well.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 01, 2018, 07:28:01 AM
Checking out the direction of that pool, it looks like the sun would set right down the centerline in late February or March. Not sure of the exact azimuth that pool is aimed at, but makes me wonder if it lines up with the equinox sunset.
Nope. It's about a month off. Sun sets right down the chute on February 20th and October 20th; not the equinoxes. Oh well.

Somewhere out there there's a similar shot from a building with the Sun setting below the lines of perspective. Well done anyway for finding this one, and entirely refuting the "horizon rises to eye level" concept. It quite clearly shows how perspective works, and the key thing is that it works just as our experience would expect it to work. Put the observer at ground level, and the perspective lines converge at ground level. Put the observer above ground level, and the perspective lines converge as shown.

Alter that picture to make the perspective lines converge on the horizon, and it would look very strange indeed - as if it were tilting away from us.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 01, 2018, 08:25:11 PM
place on a reasonably flat surface, and fill with coloured water. The water will find its own level, and give a long edge to sight along. No issues/concerns over water flow.

Alternatively, take a clear plastic bag, part-fill with coloured water, and place on absolutely anything. The water, again, will find its own level, and a sighting can be taken along the top of the water's surface.

Inclement weather last few days, but took advantage of a little bit of visible horizon today to try your idea, using a fish bowl and food-dyed water. Fluid had a little dish soap in it which I forgot about and got a bit of foam bubbles. Didn't have time to wait for them to dissipate, but just wanted to give it a try.

Didn't even bother trying to find a level spot. Just used the hood of my car. Water finds it's own level.

Lined up my phone (also using a leveling app as a double check).

(http://oi67.tinypic.com/jif887.jpg)

This was taken at an elevation about 400' above sealevel.

Don't take this as proof of anything other than concept. It's a valid critique to say the weather at the surface has provided a false horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 01, 2018, 08:36:57 PM
Don't take this as proof of anything other than concept. It's a valid critique to say the weather at the surface has provided a false horizon.
But the water container idea, along with the square lines of perspective above, has given me the idea to combine the two, using a square glass water container, like a cheap aquarium, and "shooting" the horizon through that, using the flat plane of the water as a reference to level. The additional corner edges of a rectangular tank would reinforce the level line of the water, creating means to not just compare against a vertical line, but a vanishing point.

According to FE prediction, the vanishing point should be on the horizon regardless of elevation. According to GE prediction, the vanishing point should be above the horizon, except when viewed on the surface.

This would take hardly any setup and all. I'm probably not going to haul a fish tank up a mountain, but at viewing locations near a parking area, it'd be easy.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 01, 2018, 11:12:50 PM
... the water container idea, along with the square lines of perspective above, has given me the idea to combine the two, using a square glass water container, like a cheap aquarium, and "shooting" the horizon through that, using the flat plane of the water as a reference to level. The additional corner edges of a rectangular tank would reinforce the level line of the water, creating means to not just compare against a vertical line, but a vanishing point.

According to FE prediction, the vanishing point should be on the horizon regardless of elevation. According to GE prediction, the vanishing point should be above the horizon, except when viewed on the surface.

This would take hardly any setup and all. I'm probably not going to haul a fish tank up a mountain, but at viewing locations near a parking area, it'd be easy.
Like this:
(http://oi64.tinypic.com/2s9x08n.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 01, 2018, 11:54:53 PM
Like this:


I'm impressed by the effort going into this. Of course, it won't convert one person - but it will be revealing. Note that no flat Earthers are confidently proclaiming that this will confirm their assertions because they know in their heart of hearts that it won't.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 02, 2018, 01:11:24 AM
Like this:


I'm impressed by the effort going into this. Of course, it won't convert one person - but it will be revealing. Note that no flat Earthers are confidently proclaiming that this will confirm their assertions because they know in their heart of hearts that it won't.

If the FEers were as confident as they appear to be they will be welcoming the potential for putting the seal on one of the fundamental proofs of the FE.

I suspect at present they are waiting for the outcome, and trying to find ways in advance to refute the observation/experiment, and to try to divert the discussion or to ask about ridiculous details to claim that it is not a worthy experiment.

I am pretty certain it will be unambiguous, and look forward to the pictures taken at different heights to show that there is a dip of the horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 02, 2018, 06:40:38 AM
Like this:


I'm impressed by the effort going into this. Of course, it won't convert one person - but it will be revealing. Note that no flat Earthers are confidently proclaiming that this will confirm their assertions because they know in their heart of hearts that it won't.

It is telling that it's RE people who are making effort, doing empirical experiments and it's FE people who, instead of devising their own experiments and publishing the results, are just doing everything they can to deny the results of these experiments even when they are right there in front of their eyes.

It shows that you don't need "organisation" or "funding" to do experiments, you can do some yourself at little or no cost. So why don't they? (Rhetorical question)
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 02, 2018, 08:04:33 AM
Like this:


I'm impressed by the effort going into this. Of course, it won't convert one person - but it will be revealing. Note that no flat Earthers are confidently proclaiming that this will confirm their assertions because they know in their heart of hearts that it won't.

It is telling that it's RE people who are making effort, doing empirical experiments and it's FE people who, instead of devising their own experiments and publishing the results, are just doing everything they can to deny the results of these experiments even when they are right there in front of their eyes.

It shows that you don't need "organisation" or "funding" to do experiments, you can do some yourself at little or no cost. So why don't they? (Rhetorical question)

We see regular demands that we do research. "Think for yourself!" Here's someone actually devising an experiment that can verify a key element of flat Earth theory. Since this is something that the propagandists for a globe Earth deny is real, it means that a genuine crack exists in the whole conspiracy. Ordinary people can start checking for themselves. "Wow! The horizon really does rise to eye level! Everything I know is a lie!" The Illuminati will be overthrown. The world will enter a new era of truth.

Obviously every experiment can be critiqued. What if the levelling device is sloshing around and the photo is taken when it happens to be on a slant? I would welcome every helpful suggestion to make sure that these experiments work perfectly.

Given that we are on the verge of a real breakthrough in flat Earth theory, I can't help but notice - it's a bit quiet. There's not a lot of response from the flat Earth community here. It's almost as if... kind of... they don't think that these experiments will actually support their theory. I know that can't be true, so there must be some other explanation.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 02, 2018, 08:25:29 AM
Like this:


I'm impressed by the effort going into this. Of course, it won't convert one person - but it will be revealing. Note that no flat Earthers are confidently proclaiming that this will confirm their assertions because they know in their heart of hearts that it won't.

It is telling that it's RE people who are making effort, doing empirical experiments and it's FE people who, instead of devising their own experiments and publishing the results, are just doing everything they can to deny the results of these experiments even when they are right there in front of their eyes.

It shows that you don't need "organisation" or "funding" to do experiments, you can do some yourself at little or no cost. So why don't they? (Rhetorical question)

We see regular demands that we do research. "Think for yourself!" Here's someone actually devising an experiment that can verify a key element of flat Earth theory. Since this is something that the propagandists for a globe Earth deny is real, it means that a genuine crack exists in the whole conspiracy. Ordinary people can start checking for themselves. "Wow! The horizon really does rise to eye level! Everything I know is a lie!" The Illuminati will be overthrown. The world will enter a new era of truth.

Obviously every experiment can be critiqued. What if the levelling device is sloshing around and the photo is taken when it happens to be on a slant? I would welcome every helpful suggestion to make sure that these experiments work perfectly.

Given that we are on the verge of a real breakthrough in flat Earth theory, I can't help but notice - it's a bit quiet. There's not a lot of response from the flat Earth community here. It's almost as if... kind of... they don't think that these experiments will actually support their theory. I know that can't be true, so there must be some other explanation.

Surey the best way to show that there is no sloshing is to take a short video. 10 seconds would be enough to show the water was still. After all the New Bedford experiments fundamental truth is that water MUST be level when at rest. Denying the water is level would be to deny the fundamental proofs of EnaG and the FE theory.

Another enhancement of the experiment would be to place a ruler against the glass on the far side. Knowing the length of the tank, and the amount of dip observed, one could roughly measure the angular dip, and compare it to the expected calculated amount. This would surely add substance to the calculated values available?

Eagerly awaiting the results, even though i know what they are likely to be.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 02, 2018, 09:43:09 AM
If Sam Rowbotham's method was acceptable, we should be able to replicate it, and for elevations quite higher than the top floor of the Grand Brighton.


I think it would strike me and perhaps most people that the diagram he used to show the Grand Hotel towering over the globe like a nail driven into an orange was not quite to scale, and the difference between inclination to the horizon at sea level and on the second floor of the hotel was unlikely to be significant.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 02, 2018, 09:53:02 AM
If Sam Rowbotham's method was acceptable, we should be able to replicate it, and for elevations quite higher than the top floor of the Grand Brighton.


I think it would strike me and perhaps most people that the diagram he used to show the Grand Hotel towering over the globe like a nail driven into an orange was not quite to scale, and the difference between inclination to the horizon at sea level and on the second floor of the hotel was unlikely to be significant.

Like many of his diagrams to try and prove his point.

The diagrams 15 show the piers inclined approx 20 degrees to the horizontal, just as other diagrams showing the earth, such as 20 and 24 are exaggerated to try to prove his point, and attempt make it look ridiculous for the earth to be round.
Almost all of his diagrams have errors in principle or exaggeration in them, so cannot be used as indications of much at all.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 02, 2018, 10:10:10 AM
If Sam Rowbotham's method was acceptable, we should be able to replicate it, and for elevations quite higher than the top floor of the Grand Brighton.


I think it would strike me and perhaps most people that the diagram he used to show the Grand Hotel towering over the globe like a nail driven into an orange was not quite to scale, and the difference between inclination to the horizon at sea level and on the second floor of the hotel was unlikely to be significant.

Like many of his diagrams to try and prove his point.

The diagrams 15 show the piers inclined approx 20 degrees to the horizontal, just as other diagrams showing the earth, such as 20 and 24 are exaggerated to try to prove his point, and attempt make it look ridiculous for the earth to be round.
Almost all of his diagrams have errors in principle or exaggeration in them, so cannot be used as indications of much at all.

Problems with that measurement -


The chief merit of his experiment is to show his capacities and a thinker and a scientist.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 02, 2018, 11:10:30 AM
If Sam Rowbotham's method was acceptable, we should be able to replicate it, and for elevations quite higher than the top floor of the Grand Brighton.


I think it would strike me and perhaps most people that the diagram he used to show the Grand Hotel towering over the globe like a nail driven into an orange was not quite to scale, and the difference between inclination to the horizon at sea level and on the second floor of the hotel was unlikely to be significant.

Like many of his diagrams to try and prove his point.

The diagrams 15 show the piers inclined approx 20 degrees to the horizontal, just as other diagrams showing the earth, such as 20 and 24 are exaggerated to try to prove his point, and attempt make it look ridiculous for the earth to be round.
Almost all of his diagrams have errors in principle or exaggeration in them, so cannot be used as indications of much at all.

Problems with that measurement -

  • He doesn't give the height of the hotel
  • He doesn't describe his equipment in detail
  • He doesn't calculate the expected angle to a horizon on the globe
  • He doesn't express the degree of accuracy of his equipment

The chief merit of his experiment is to show his capacities and a thinker and a scientist.

I would hesitate to call him a scientist, as he does not show method, and he uses preconceived ideas, ie the world is flat, to justify some of his arguments.
The later chapters on daylight in the Antarctic says that as he has proved the world is flat, and evidence to the contrary must be false and discarded.
Hardly the approach of a scientist.
A real scientist would have described the instruments in his method, and addressed the list you noted as well.

Luckily for us the Grand hotel in Brighton still stands, and we can find pictures of it, and have an idea of what his experiment was looking at, and understand that he was not really high off the ground.

In October i will have a reason to go near the old Bedford river, and have a mind to get in a small boat, and see if i can actually see the bridge in the experiment. Maybe if it is calm enough, even take a picture. I wonder if that would show anything interesting?

Not sure hope to describe him really, a philosopher? Pseudoscientist? Or just religious preacher? Or a combination?
Not a scientist for sure.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 02, 2018, 06:44:34 PM
Eagerly awaiting the results, even though i know what they are likely to be.
Even though it's been overcast, it's a ceiling and I had a sharp contrast horizon today, so I took a cheap plastic aquarium to just try out proof of concept.

Not good. The tank really needs to be good and square (not rounded corners) and the sight through the transparent layer (glass, plastic) very clear. I measured and drew in index lines at every 1" horizontal on the tank itself, but when I tried to draw in perspective lines in the captured images, I got two different apparent focal points (and even those merged to a small area of uncertainty and not a precise fix).

This is just for fun, mainly, so I'm hesitant to go out and spend over $20 on a rectangular glass fish tank just for this. Maybe I can find one at a swap meet or garage sale this weekend for under $10.

One thing that did become apparent was water tension wouldn't give me a clean level line. Maybe it was the plastic. Or maybe I need to add something like antifreeze or dish soap. I just used plain bottled water with some food dye, but in places, it would "reach" up along the edge and ruin the straight edge. Also, trying to sight exactly level along the surface of the tank liquid is quite difficult. You really need to move off axis to line up the liquid level along the back edge with the side, and create a straight line with those two. But then you lose the perspective lines of the tank, which is the whole point of using the tank instead of the hydrostatic water level with the tubing.

I thought of adding two little floats with cross hairs on the level water and then use those like a gun sight. But the simplest way to me seems to not even worry about sighting level with the water and just let the perspective lines tell you where the vanishing point of "eye-level" is. I just don't know if skeptics will buy that, even though perspective and vanishing point is their argument for the apparent horizon.

(Of note, it's almost impossible to do this where I want to do it without drawing attention. When asked, I just explained I was recording observations for an optics/perspective demonstration and didn't mention anything about it being related to the globe/flat earth debate. I may be open minded, but I'm still in the closet about how much attention I've been giving the subject lately.)
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 02, 2018, 10:56:23 PM
I thought of adding two little floats with cross hairs on the level water and then use those like a gun sight. But the simplest way to me seems to not even worry about sighting level with the water and just let the perspective lines tell you where the vanishing point of "eye-level" is. I just don't know if skeptics will buy that, even though perspective and vanishing point is their argument for the apparent horizon.


Forget about convincing sceptics. They won't be convinced, regardless. After your results are posted, they'll carry on citing Rowbotham and the horizon rising to eye level as if you hadn't posted anything. What you're doing - designing an experiment to determine whether a phenomenon exists, and adapting it to fit circumstances.

I note that things have been very, very quiet here for a while - which is perhaps a tribute to the effectiveness of your experiments.

Title: Re: The Horizon is Always at Eye Level
Post by: kasai on May 03, 2018, 05:49:27 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.
Dude I feel so honored being your favorite person on the site. *Sarcasm* But fr though eye level would mean stand up straight and look straight out. Horizon will be at your eyes. Basically that's what eye level means.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 03, 2018, 06:02:04 PM
...eye level would mean stand up straight and look straight out. Horizon will be at your eyes. Basically that's what eye level means.
I think we agreed that "eye-level" means straight out. We don't agree that that's where the horizon appears. That's what this discussion topic is addressing.
 
Horizon will be at straight out (no angle downward) according to flat surface earth explanation.
(http://oi67.tinypic.com/zlbw2e.jpg)

Horizon will be at an angle below straight out according to spherical surface explanation.
(http://oi66.tinypic.com/es9ohy.jpg)

Determining if the horizon is always at eye level is the objective.
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on May 03, 2018, 06:04:24 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.
Dude I feel so honored being your favorite person on the site. *Sarcasm* But fr though eye level would mean stand up straight and look straight out. Horizon will be at your eyes. Basically that's what eye level means.
Not exactly a precise definition. Looking straight out could well be Polaris for all you've defined it. I know you'd reject that as definitely eye level, but my point is, you need to define "straight out" better.
Title: Re: The Horizon is Always at Eye Level
Post by: kasai on May 03, 2018, 06:12:05 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.
Dude I feel so honored being your favorite person on the site. *Sarcasm* But fr though eye level would mean stand up straight and look straight out. Horizon will be at your eyes. Basically that's what eye level means.
Not exactly a precise definition. Looking straight out could well be Polaris for all you've defined it. I know you'd reject that as definitely eye level, but my point is, you need to define "straight out" better.
Is it really that hard to understand what we mean? I'm done with this thread, and not because I'm losing, I'm not, you round heads have to make everything we say so complicated. The simplicity of the things we say. My brain cells are dying because of you round heads. I'm done.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 03, 2018, 08:48:12 PM
...eye level would mean stand up straight and look straight out. Horizon will be at your eyes. Basically that's what eye level means.
I think we agreed that "eye-level" means straight out. We don't agree that that's where the horizon appears. That's what this discussion topic is addressing.
 
Horizon will be at straight out (no angle downward) according to flat surface earth explanation.
(http://oi67.tinypic.com/zlbw2e.jpg)

Horizon will be at an angle below straight out according to spherical surface explanation.
(http://oi66.tinypic.com/es9ohy.jpg)

Determining if the horizon is always at eye level is the objective.

The stupid thing about all this is the reality if we did live on a flat earth is the horizon would still not be at eye level.
If I amend your diagram to show a flat plane instead of a curve and we agree that you can only see a finite distance then you'd still be looking down to as far as you can see:

(https://image.ibb.co/fxUSB7/horizon.jpg)

The other stupid thing is that horizon dip can be measured. It is observable and the perspective lines idea makes it 4 different ways that has been shown on here recently which prove that. Why are FE people denying all this proof and if they dispute the findings they can devise their own experiments, but they don't.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 03, 2018, 09:43:23 PM
The stupid thing about all this is the reality if we did live on a flat earth is the horizon would still not be at eye level.
If I amend your diagram to show a flat plane instead of a curve and we agree that you can only see a finite distance then you'd still be looking down to as far as you can see:

(https://image.ibb.co/fxUSB7/horizon.jpg)
Except the flat earth contention is that the ground plane appears to rise to eye level. So even looking straight ahead (no angle downward), the horizon is at eye level.

This is the vanishing point argument. If you look straight ahead, that's where that particular ocular vanishing point is. If you look up, that's another vanishing point. But straight ahead, due to perspective, the vanishing point appears on the horizon.

And that's a convention oft repeated in art direction. The horizon is the straight-ahead vanishing point. Squat down? Still on the horizon. Stand up? Horizon. 3rd story of the Grand Brighton? VP still on the horizon.

It works for everyday situations when your perspective is relatively near the ground.

But what I don't see is anyway to calculate such a distance as if it's anything actually empirical and not just a principle. That's why I call such a horizon "apparent." It depends on visual acuity, resolution, focal length, etc. And even then, is it anything more than subjective?

The horizon on a curved surface is something real. It's a quantifiable distance that factors height and radius of the sphere to know where that tangent line is. It's not "apparent."

I've kind of stopped worrying about how an art/drawing principle of capturing a 3D space on a 2D medium can be applied to understanding physical space. So the ground appears to rise and the sky appears to descend, FE says. So what? If that's what flat earth believes, I'm not going to change minds.

But it ought to be measurably verifiable whether or not a horizon is always level with the eye. It's not proving to be so, so even if it were an attribute of a flat plane perspective, it definitely is not one in space with spherical geometry. So, it seems reasonable to me that if it's a discriminator between flat and spherical, it ought to settle the matter. And I think anyone could check, as long as it's not done sloppily, which is how Rowbotham's experiment seems to have been accomplished. But you don't need a government agency or MIT team to verify. You don't need expensive equipment.

If the horizon DOES always measure to be level to the eye (not appear; be measurable on the horizontal), then it refutes the globe. If it doesn't, then that's a big point in globe's favor and maybe then flat earth proponents will abandon the vanishing point argument.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 03, 2018, 10:55:18 PM
I understand the assertion that the horizon rises to eye level but if you think about it theoretically if you're looking at the ground 1 foot in front of you then you're looking down at an angle. If you're looking at the ground one mile in front of you then you are also looking down at an angle, just a shallower one.
The further you look the shallower that angle becomes. At what point does that angle become 0? At infinity.
And given we can only see a finite distance, the horizon cannot be exactly at eye level because if the earth is flat you will always be looking down at a slight angle.
It's a triangle. H is one side, the ground is the other side and the hypotenuse is the line from your eye to the ground. So there has to be an angle, even if it's a shallow one.

So that is the theory, but that also matches the empirical observations. Why are FE, who claim to be empiricists, denying empirical observations which show that horizon isn't at eye level?
Or rather, where is their empirical evidence showing that it does?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 03, 2018, 11:40:11 PM
I don't know.

(http://oi67.tinypic.com/2q8xbp1.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 04, 2018, 07:23:32 AM
Is it really that hard to understand what we mean?

Not hard to understand at all, just that what you say you mean is most often filled with towering vagueness.

If something is 1 foot in front of me, and at exactly 6ft off the ground, I can confidently say it is at eye level. This becomes more difficult to say with certainty as it gets farther away.

When a flat earther takes a picture from a plane, and claims the horizon to be at eye level, then what height is the flat earther at? Was the camera held to their eye, or not? If the plane is at 38,000 feet, do we take 'eye level' as 38,006, or 38,003 because the flat-earther was in their seat? Is the flat-earther claiming a horizon at eye-level because they've put the horizon at centre frame, without any kind of levelling device, or not?
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 04, 2018, 07:28:54 AM
I understand the assertion that the horizon rises to eye level but if you think about it theoretically if you're looking at the ground 1 foot in front of you then you're looking down at an angle. If you're looking at the ground one mile in front of you then you are also looking down at an angle, just a shallower one.
The further you look the shallower that angle becomes. At what point does that angle become 0? At infinity.
And given we can only see a finite distance, the horizon cannot be exactly at eye level because if the earth is flat you will always be looking down at a slight angle.
It's a triangle. H is one side, the ground is the other side and the hypotenuse is the line from your eye to the ground. So there has to be an angle, even if it's a shallow one.

So that is the theory, but that also matches the empirical observations. Why are FE, who claim to be empiricists, denying empirical observations which show that horizon isn't at eye level?
Or rather, where is their empirical evidence showing that it does?

This is part of the original confused thinking going back to Rowbotham. Clinging to this confused thinking is central to the project. Thinking clearly would derail the whole thing.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 04, 2018, 10:12:02 AM
This is part of the original confused thinking going back to Rowbotham. Clinging to this confused thinking is central to the project. Thinking clearly would derail the whole thing.
Thing is, if they are going to claim to be empiricists and state how important empirical evidence is then...you know, they could try and make some empirical measurements.
Crazy idea, I know, but it might just work.
It's bizarre that they cite ridiculous write ups from Rowbotham of experiments in a hotel which isn't tall enough to easily measure any difference in horizon tip and then deny the evidence of their own eyes when they're shown photos and video of multiple ways to show horizon dip. Here is another:

https://www.youtube.com/watch?v=F5wvLeRVKpo
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on May 04, 2018, 02:03:21 PM
This is part of the original confused thinking going back to Rowbotham. Clinging to this confused thinking is central to the project. Thinking clearly would derail the whole thing.
Thing is, if they are going to claim to be empiricists and state how important empirical evidence is then...you know, they could try and make some empirical measurements.
Crazy idea, I know, but it might just work.
It's bizarre that they cite ridiculous write ups from Rowbotham of experiments in a hotel which isn't tall enough to easily measure any difference in horizon tip and then deny the evidence of their own eyes when they're shown photos and video of multiple ways to show horizon dip. Here is another:

https://www.youtube.com/watch?v=F5wvLeRVKpo

There was some excuse for Rowbotham - he would have found it difficult to get up in a balloon - but all you need to do is look out of the window and the horizon is clearly below eye level at altitude. You could sight along a spirit level or your complimentary glass of champagne, but you can easily just eyeball it.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 04, 2018, 02:15:15 PM
It might have been difficult, but certainly not impossible, as he quoted a number of times accounts of balloon pilots.
Unfortunately most of the accounts were not scientific, and scalped from different publications and newspapers.

So not Zetetic at all.

These days much much easier to get to a point up high, even if it is a high point overlooking the ocean
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 04, 2018, 02:26:22 PM
There's this which Tom quoted in a previous thread about this:

Quote
"The chief peculiarity of a view from a balloon at a consider-able elevation, was the altitude of the horizon, which remained practically on a level with the eye, at an elevation of two miles

Source: http://www.sacred-texts.com/earth/za/za15.htm

I've highlighted the word which is a slight weakness in the argument. Practically. Yes, at two miles the horizon dip would be less than 2 degrees.
Not necessarily that easy to discern, but perfectly possible to measure with the right equipment.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 04, 2018, 04:28:26 PM
The concept of "zetetic" is confusing to me. Rowbotham stands it in contrast to "theoretic," which is connoted disparagingly with "speculative."

But also, there seems to be an element of skepticism in the zetetic mind, as if to say don't take anyone's word for something or to beware of being influenced by pre-conceived notions. Find out for yourself.

If so, it seems odd to me, then, that principle of "the horizon is always at eye level" is accepted as an axiom by those claiming to be zetetic. The principle of perspective in art says the vanishing point is at the horizon. Rowbotham's experiment (with vagueness as to how) claimed to have affirm this principle. But the zetetic mind shouldn't accept it just because Rowbotham said he confirmed it 150 years ago, nor just because artists use the principle to convey 3D in a 2D medium.

I believe Rowbotham's experiment/observation was wrong. I also believe that in art, the horizon is in most instances closely level with the horizontal sight line. But while the vanishing point surely rises with elevation (or swings to whatever the ocular focal point one might have), it's contested whether or not the horizon rises with it. The horizon and vanishing point are not tied together as perspective principle has been interpreted. People need to, and can, test and verify for themselves. As I understand it, the zetetic philosophy demands that.
Title: Re: The Horizon is Always at Eye Level
Post by: SpaceCadet on May 05, 2018, 03:25:23 PM
In my opinion, the term Zetetic as with regards to flat earth means "accept any statements about observation that supports flat earth"

Few flat earthers ever conduct any sort of experiments with a view to removing  possible errors or even designing experiments that have a sound basis in the first place. Flat earth research is mainly watching flat earth youtube videos sprinkled with pointless spirit- levels -on -airplanes attempt to find a dip that by it's nature shouldn't even be there in the first place.

This is a thread 5 pages long with the only 2 flat earth responses being "you cannot be anywhere near Rowbotham's accuracy" and "I'm out because you all don't understand us as we don't understand math". You would expect the so called Zetetics to be out in force trying to design an experiment that they can all do to observe for themselves. But noooo. Much easier to watch youtube.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 06, 2018, 10:30:46 PM
I don't have a clear horizon today, but this is what I think I'm going with for measuring whether or not the horizon is always at eye-level.

(http://oi63.tinypic.com/2rf4pig.jpg)

It's a square wire frame shelving assembly that provides a converging set of orthogonal perspective lines when viewed through its center.

I attached a water leveling tube to the left sight for leveling pitch (forward/backward tilt) and a guide line between two orthogonal lines to serve as a transverse sight. Line that up so that it and the two (left/right) orthogonals make a straight line, and that's your vanishing line, which either will or won't line up with the horizon (as long as the rig is level, 90° to vertical. That's what the water level in the tubing is for.

All of the other orthogonal lines should converge on that transverse to give you vanishing point, which would need to be added in post:

(http://oi63.tinypic.com/2hzslef.jpg)

Today, the horizon lies somewhere between the two small red lines I added.

Honestly, with this, you don't even need to get the camera/eye right at that level line. The vanishing point will change with any camera elevation, and you can figure out where that is by drawing in where the lines converge:

(http://oi64.tinypic.com/29c2bvc.jpg)

But you can't do that in real time, at time of survey. You can only do that digitally after seeing the picture. But the vanishing point/line will rise or fall with camera/eye elevation.

The question is, will the horizon line follow the vanishing point?

This viewpoint is about 400' above MSL. The other coastal viewpoints I have planned are around 700', 1100', and 1700'. Unless anyone (and I mean anyway - flat earth proponents or critics) has any critiques of this tool, I hope to get images this week, weather permitting.
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on May 06, 2018, 11:59:03 PM
I think you should make the leveling water easier to see.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 07, 2018, 12:06:45 AM
I think you should make the leveling water easier to see.
On it.

Also adding a level for the roll axis.
Also replacing the twine with taut wire.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 08, 2018, 08:00:26 PM
Now, just waiting on a clear horizon. It's "June Gloom" time of year in SoCal when a low cloud cover called the marine layer persists for weeks, extending inland oftentimes over night and into late morning. It "burns off" as the day progresses (and land warms) but just moves off shore giving us clear skies but a heavy haze toward the horizon.

So I've been left with a haze or cloudy horizon; which might look like a horizon but it's false. Actual horizon is lower; hidden.

My set up: my orhogonal water level is now 1" vinyl tubing giving a better sight line (for pictures). I've got a tranverse leveler too, but that's just for making sure the cube is level for perspective/vanishing point analysis.

I stuck with twine interwoven through the grating. Found wire hard to work with and it would retain bends. I use a straight edge to adjust to twine (under tension) and can tweak its height to match the water level. Makes it much each to shoot a sighting across the two liquid reservoirs.

(http://oi63.tinypic.com/oppvzd.jpg)

A solid platform that can be leveled is essential. Not carrying this stool up the mountain, so not sure what I'll use at that location.

Leveling is only necessary for the perspective part of the sighting. The water will do its own leveling. I just want the cube to be square and level too so that the vanishing lines are true and can compare with the water level sight line.

On setup, I make sure the cube is square and not sagging by measuring corner to corner. Also made sure the corners are as deep and secure in the apex connectors as possible, and zip tied all panels together so the don't come loose.

Use a pair of bubble levels (and my phone) to make sure all level in both axes, using shims under the stool legs to adjust.

Camera set up on tripod, can adjust height to gain different perspective angles, or line up with water, using guideline as a sighting aid. I prefer to take photos centered through the cube, but can shift left to overlap the two sighting tubes. It just alters the perspective.

As precise as I can be using basic items from home or hardware store, this is still a crude setup that can't measure precise angles. But all we want is to see if horizon is always at "eyelevel." I would wager that my approach is more meticulous and considered than was Samuel Rowbotham's in experiment 15.

Now, just give me a good view to the horizon and we'll see.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 08, 2018, 08:42:39 PM
Don't interpret these as answering the horizon question since the actual horizon is obscured by marine layer, but here are some examples of how this will be used:

Example 1 is view taken from a perspective of lining up the transverse guideline with the orthogonal water level. The camera is elevated to be "eye-level," meaning it is looking 90° to horizontal and in-line with the sighting water level. The camera is also centered laterally on the cube, so that all of the perspective lines should converge on the level line, as long as the cube is square and also horizontally leveled:

(https://3.bp.blogspot.com/-jzdp3luCU2c/WvIHVe1ErMI/AAAAAAAAJgU/iSax_FUzZ_gfNW16VEkPtnlh_ZNpxnsGgCLcBGAs/s1600/Example%2B1.jpg)

I could (and probably will) fill the water level so that it matches the half-point of the cube's elevation. It doesn't have to be, but it's easier to understand, possibly, if everything is centered.

 Example 2: the only adjustment here is to camera elevation. The cube/water level and camera centering is all the same. But now "eye-level" is with the cube centroid, which is slightly lower than the water levels. But using perspective, we can still find that the vanishing point lines converge.

(https://3.bp.blogspot.com/-NaU1uZc2Zdw/WvIHv7-t8sI/AAAAAAAAJgc/OF-FvVaaNpwKxoKKk6Q3vTfff3SLO9-BACLcBGAs/s1600/Example%2B2.jpg)

It's not perfect and there is some margin for area in drawing the lines of perspective, so instead of a point, there's an area of uncertainty which I estimated by drawing a small red circle. Drawing in the perspectives lines is mainly an addition to the water level sighting line, which can also be imperfect due to the thickness of the transparent vinyl and any adhesion of the water to the inside of the tube that can add small amounts of error in the sighting line.

But I predict that horizon "rising" will be less than these margins of error/uncertainty such that even with them being accounted for, we'll see if the horizon doesn't rise to "eye-level" with increasing vantage point elevation. It may be not be definitive at 400' MSL (which is where these photos were shot), but at 700', 1100' and 1700' I anticipate less uncertainty.

If not; if the gap between "eye-level" line and the apparent horizon remains small and within the margins of error inherent in a homemade device like this, then that will score in favor of a flat earth topology.

Please...please: if there are any flat earth proponents who challenge this approach, please do so before I take actual sightings. But if you do, also explain why and maybe offer suggestions as to how to improve or correct any deficiencies in this methodology.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 08, 2018, 08:55:16 PM
This is a very impressive bit of work and puts to shame the FE empiricists who are refusing to do any experiments and hiding behind things like a lack of funding - as though you're being sponsored to do any of this.

I'm interested to know what problem Tom will find with this to explain away the results when you have more conclusive ones. As you say, it would be nice if he states those before you waste your time. I honestly think he needs to conduct his own experiments - you have shown you can do this off your own back and you don't need a budget and if he's only going to believe his own experiments (or Rowbotham's) then he should do some himself.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 08, 2018, 09:51:03 PM
Thanks; but even though I do hold to a prediction as to what this should demonstrate, I'm self-wary of introducing that bias into the setup or inadvertently skewing any observation just so it matches my preconceptions.

Which is why I'm strongly encouraging input beforehand vice having folks critique after the fact should results not be what some faction wants.

Ideally, it would be great if rather than depending on my observation, anyone could go out and assemble something like this and see if results differ from whatever I get. I don't even think you need an open water horizon. I think any flat plain will work as long as you can find sufficient elevation. A few stories of a building won't do given the margins of error a homemade device involves.

The cage/cube isn't necessary either. I just like the idea of mapping lines of perspective too since that's a key component of the flat earth ecplanation of "horizon." It just requires more care in squaring corners and getting the rig square to perpendicular, else the lines of perspective will point along an inclined plane.

But for just "eye-level" sighting, you don't need all that. All I suggest be added to those devices in the YouTube video is that the rig be mounted in a stable fashion rather than hand held. And if taking photos or video, have the camera stably mounted and well aligned before shooting.

An eye-level (viewline 90 degrees to perpendicular) vanishing point will rise with elevation. The question at hand is whether or not horizon line will follow and rise as well to match that horizontal vanishing point (line). FE says yes. GE says no.

Whatever the answer, it's been fun thinking it through.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 09, 2018, 07:03:56 AM
This is all very nice and demonstrates very well how perspective works in the real world, but I guess that will not impress any EnaG believer. If you look it up, they construct "perspective lines" in a very different way. First they place the vanishing point, which is given by a right-angled triangle, where the hypotenuse is the direct line between your eyes and the vanishing point. One cathetus is down from your eyes to sea level, the other one going from there to the vanishing point. The angle at the vanishing point is fixed, therefore the vanishing point is moving away if you go higher.

Everything behind this vanishing point you can't see, everything in front adopts in size so that it fits into the triangle. The angle is defined by the optical resolution of your eyes. Therefore, if you take a telescope, the angle changes and the vanishing point is moving further away, which leads to the recovery effect.

That's a kind of far-field perspective, where the Euclidean geometry is no longer valid. You demonstrate near-field perspective, which goes along with Euclidean geometry. To disprove this concept, you would need a device that goes from you to the horizon. But that's not possible. And something like railway tracks does not help, because that's give you no conclusive result. Because they are to narrow and apparently melt into a single point at the horizon and if you climb up, the horizon will indeed move away while the tracks apparently still melt into one point at the horizon.

It's a debate you can not win, because for every proof you show, they will demand another one that will set the level for you even higher...         
Title: Re: The Horizon is Always at Eye Level
Post by: SiDawg on May 10, 2018, 03:09:09 AM
Very cool! I would draw a straight black vertical line on both "leveling tubes" and use the point that crosses the liquid as the guide (looks like you've just drawn two lines, one based on the middle of the liquid, one on the edge yeah? But the angle of the camera will affect both of those points). If you draw a line in exactly the same spot on both tubes it should fix that. That level line is crucial so prove you're not pointing "upwards" away from the horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 10, 2018, 10:03:02 AM
I would suggest ditching the flexi plastic tube, repeat the U-shaped assembly on the RHS, and link the horizontal members of each U across the cage. Then there will be just one body of water finding its level across the four corners, with each corner linked
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 10, 2018, 10:26:22 AM
This is all very nice and demonstrates very well how perspective works in the real world, but I guess that will not impress any EnaG believer. If you look it up, they construct "perspective lines" in a very different way. First they place the vanishing point, which is given by a right-angled triangle, where the hypotenuse is the direct line between your eyes and the vanishing point. One cathetus is down from your eyes to sea level, the other one going from there to the vanishing point. The angle at the vanishing point is fixed, therefore the vanishing point is moving away if you go higher.

Everything behind this vanishing point you can't see, everything in front adopts in size so that it fits into the triangle. The angle is defined by the optical resolution of your eyes. Therefore, if you take a telescope, the angle changes and the vanishing point is moving further away, which leads to the recovery effect.

That's a kind of far-field perspective, where the Euclidean geometry is no longer valid. You demonstrate near-field perspective, which goes along with Euclidean geometry. To disprove this concept, you would need a device that goes from you to the horizon. But that's not possible. And something like railway tracks does not help, because that's give you no conclusive result. Because they are to narrow and apparently melt into a single point at the horizon and if you climb up, the horizon will indeed move away while the tracks apparently still melt into one point at the horizon.

It's a debate you can not win, because for every proof you show, they will demand another one that will set the level for you even higher...         

I see that someone here has actually read Earth Not a Globe.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 10, 2018, 03:15:15 PM
Very cool! I would draw a straight black vertical line on both "leveling tubes" and use the point that crosses the liquid as the guide (looks like you've just drawn two lines, one based on the middle of the liquid, one on the edge yeah? But the angle of the camera will affect both of those points). If you draw a line in exactly the same spot on both tubes it should fix that. That level line is crucial so prove you're not pointing "upwards" away from the horizon.
Good idea.

I've also added some t-square stiffeners to limit any tendencies of the square to squash to a trapezoidal shape.
Added a torpedo level and a plumb bob.
Added caps to the tubes so that I didn't have to keep emptying to move and refilling to use. (Caps removed during leveling and sighting of course.)

The transverse sighting line actually tends to be more of a hindrance than an aid. Good for lining up and extending the sightline left-to-right from the two water level tubes, but then it obscures the horizon. So, I've made it so that I can adjust it a little. Use it to level, but then slide it up or down until flush with a cage othogonal wire. It'll still cross the field of view, but well above or below any possible horizon line I may observe at elevations I've chosen.

Or, I might get rid of it altogether. It's just that the best way to line up water levels is to move off center and line up the tubes. But I want shoot from the centroid, which is probably just an aesthetic choice. I want those perspective lines to be centered, if only to confirm that the whole rig is truly square and has been set up horizontally, with no introduced pitch or roll.

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 10, 2018, 03:25:57 PM
I would suggest ditching the flexi plastic tube, repeat the U-shaped assembly on the RHS, and link the horizontal members of each U across the cage. Then there will be just one body of water finding its level across the four corners, with each corner linked
I wasn't even going to put in that extra tubing. It's only there to add leveling confidence in the roll axis. But in light of the post I just made about the challenge of making a sight along the level lines, maybe that's a good idea. Without an actual horizon to shoot due to meteorological conditions, I find myself tinkering and tweaking this apparatus, so I could do that too.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 10, 2018, 03:33:03 PM
This is all very nice and demonstrates very well how perspective works in the real world, but I guess that will not impress any EnaG believer. If you look it up, they construct "perspective lines" in a very different way. First they place the vanishing point, which is given by a right-angled triangle, where the hypotenuse is the direct line between your eyes and the vanishing point. One cathetus is down from your eyes to sea level, the other one going from there to the vanishing point. The angle at the vanishing point is fixed, therefore the vanishing point is moving away if you go higher.

Everything behind this vanishing point you can't see, everything in front adopts in size so that it fits into the triangle. The angle is defined by the optical resolution of your eyes. Therefore, if you take a telescope, the angle changes and the vanishing point is moving further away, which leads to the recovery effect.

That's a kind of far-field perspective, where the Euclidean geometry is no longer valid. You demonstrate near-field perspective, which goes along with Euclidean geometry. To disprove this concept, you would need a device that goes from you to the horizon. But that's not possible. And something like railway tracks does not help, because that's give you no conclusive result. Because they are to narrow and apparently melt into a single point at the horizon and if you climb up, the horizon will indeed move away while the tracks apparently still melt into one point at the horizon.

It's a debate you can not win, because for every proof you show, they will demand another one that will set the level for you even higher...         

I see that someone here has actually read Earth Not a Globe.
Well, I have too -- both editions. Can't say I understand the flat earth explanation for horizon, but for this effort, all that matters is whether or not the horizon is level with the eye, regardless of why or why not.
Title: Re: The Horizon is Always at Eye Level
Post by: kasai on May 10, 2018, 06:10:35 PM
...eye level would mean stand up straight and look straight out. Horizon will be at your eyes. Basically that's what eye level means.
I think we agreed that "eye-level" means straight out. We don't agree that that's where the horizon appears. That's what this discussion topic is addressing.
 
Horizon will be at straight out (no angle downward) according to flat surface earth explanation.
(http://oi67.tinypic.com/zlbw2e.jpg)

Horizon will be at an angle below straight out according to spherical surface explanation.
(http://oi66.tinypic.com/es9ohy.jpg)

Determining if the horizon is always at eye level is the objective.

The stupid thing about all this is the reality if we did live on a flat earth is the horizon would still not be at eye level.
If I amend your diagram to show a flat plane instead of a curve and we agree that you can only see a finite distance then you'd still be looking down to as far as you can see:

(https://image.ibb.co/fxUSB7/horizon.jpg)

The other stupid thing is that horizon dip can be measured. It is observable and the perspective lines idea makes it 4 different ways that has been shown on here recently which prove that. Why are FE people denying all this proof and if they dispute the findings they can devise their own experiments, but they don't.
Denying this proof?!?!? You're showing us a diagram, how can anyone just believe in this diagram. How would I know this is what happens. Get off this site.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 10, 2018, 06:17:26 PM
Sit down before you hurt yourself.
The diagrams show the theory of why you should see horizon dip on a globe earth. The four different experiments which have been posted on here recently are the proof that the theoretical dip can be observed.
Title: Re: The Horizon is Always at Eye Level
Post by: junker on May 11, 2018, 01:40:44 AM
Get off this site.

Don't do that in the upper fora. Warned.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 11, 2018, 02:01:23 PM
Without an actual horizon to shoot due to meteorological conditions, I find myself tinkering and tweaking this apparatus...
May be awhile before I can get a clear shot at a true horizon.
http://www.sandiegouniontribune.com/weather/sd-me-may-gray-20180507-story.html (http://www.sandiegouniontribune.com/weather/sd-me-may-gray-20180507-story.html)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 12, 2018, 09:24:24 PM
I've also added some t-square stiffeners to limit any tendencies of the square to squash to a trapezoidal shape.
Added a torpedo level and a plumb bob.
Added caps to the tubes so that I didn't have to keep emptying to move and refilling to use. (Caps removed during leveling and sighting of course.)

The transverse sighting line actually tends to be more of a hindrance than an aid. Good for lining up and extending the sightline left-to-right from the two water level tubes, but then it obscures the horizon. So, I've made it so that I can adjust it a little. Use it to level, but then slide it up or down until flush with a cage othogonal wire. It'll still cross the field of view, but well above or below any possible horizon line I may observe at elevations I've chosen.

Or, I might get rid of it altogether. It's just that the best way to line up water levels is to move off center and line up the tubes. But I want shoot from the centroid, which is probably just an aesthetic choice. I want those perspective lines to be centered, if only to confirm that the whole rig is truly square and has been set up horizontally, with no introduced pitch or roll.
After over-engineering this thing, it was getting to unwieldy. I'm on v1.3.

1. I'm down to just the two large sighting tubes, connected by a single tube. I've ditched the cross-connecting tubing in favor a torpedo level and plumb bob to ensure the rig is square and level.
2. I can now break it down and build it up on site so it's more portable when hiking up to the highest planned survey point.
3. I am mounting it on angle irons, set on a cross plank that will balance nicely on a good, tripod (which also has leveling bubbles).
4. I moved the sighting tubes to the outside of the cube so that they don't obstruct the perspective lines of the cube.
5. I've got a sight line strung across the midpoint transverse that, along with the plumb bob line gives me an excellent centroid index.

I've tested it and I can consistently get correlation between the converging perspective lines and the horizontal sight line of the water level tubes. Now, all I need is a horizon to "shoot." Waiting on the weather.

in the meantime, I did some calculating. If we are on a flat surface, I should find the horizon at level no matter what my elevation. But if we are on a convex surface of the size ascribed by globe advocates, then the following should be observed:

At 100' elevation, the visual horizon calculates to around 64,684' without refraction. (69,696' with standard atmospheric refraction; 74,691' on days with exceptional refraction index.)
With a camera set level, 30 inches back from my sighting guides, I should get a 0.089° drop of the horizon below level. Not much. My guide lines are 1/25th of an inch wide (0.039" = 1mm).
From 30" away, that 0.089° drop would measure 0.043-0.047", or just about 1 width of my guideline.

Doing the same thing for other elevations:
At 400', the measured drop would be 0.086-0.93" or ~2x the width of my sighting line.
At 700', the measured drop would be 0.114-0.123" or ~3x the width of my sighting line.
At 1160', the measured drop would be 0.147-0.158" or ~4x the width of my sighting line.
At  1380', the measured drop would be 0.16-0.172" or <4x the width of my sighting line.

I know all I'm doing really is detecting whether or not any drop below my sighting line occurs, but I wanted to see what to expect.
Though the main leveling tool is the water level, the added cube framework should provide lines of perspective that converge on the sight line rather than the horizon, as long as there is no pitch to the apparatus. The water levels, the torpedo level, the plumb bob and the tripod's level itself should all agree and confirm that there is no pitch tilt.

I feel this is much more precise (and duplicate-able) than the vague description given by Rowbotham in Experiment 15, that has supported the "horizon is always at eye-level" claim for years. Plus, I intend to attain elevations much higher than the top floor of the Grand Brighton.

If not--if there's something I'm missing or that's inherently flawed in this approach that Rowbotham avoided--speak up so I can address them before gathering measurements.
 
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 13, 2018, 02:08:21 AM
I've also added some t-square stiffeners to limit any tendencies of the square to squash to a trapezoidal shape.
Added a torpedo level and a plumb bob.
Added caps to the tubes so that I didn't have to keep emptying to move and refilling to use. (Caps removed during leveling and sighting of course.)

The transverse sighting line actually tends to be more of a hindrance than an aid. Good for lining up and extending the sightline left-to-right from the two water level tubes, but then it obscures the horizon. So, I've made it so that I can adjust it a little. Use it to level, but then slide it up or down until flush with a cage othogonal wire. It'll still cross the field of view, but well above or below any possible horizon line I may observe at elevations I've chosen.

Or, I might get rid of it altogether. It's just that the best way to line up water levels is to move off center and line up the tubes. But I want shoot from the centroid, which is probably just an aesthetic choice. I want those perspective lines to be centered, if only to confirm that the whole rig is truly square and has been set up horizontally, with no introduced pitch or roll.
After over-engineering this thing, it was getting to unwieldy. I'm on v1.3.

1. I'm down to just the two large sighting tubes, connected by a single tube. I've ditched the cross-connecting tubing in favor a torpedo level and plumb bob to ensure the rig is square and level.
2. I can now break it down and build it up on site so it's more portable when hiking up to the highest planned survey point.
3. I am mounting it on angle irons, set on a cross plank that will balance nicely on a good, tripod (which also has leveling bubbles).
4. I moved the sighting tubes to the outside of the cube so that they don't obstruct the perspective lines of the cube.
5. I've got a sight line strung across the midpoint transverse that, along with the plumb bob line gives me an excellent centroid index.

I've tested it and I can consistently get correlation between the converging perspective lines and the horizontal sight line of the water level tubes. Now, all I need is a horizon to "shoot." Waiting on the weather.

in the meantime, I did some calculating. If we are on a flat surface, I should find the horizon at level no matter what my elevation. But if we are on a convex surface of the size ascribed by globe advocates, then the following should be observed:

At 100' elevation, the visual horizon calculates to around 64,684' without refraction. (69,696' with standard atmospheric refraction; 74,691' on days with exceptional refraction index.)
With a camera set level, 30 inches back from my sighting guides, I should get a 0.089° drop of the horizon below level. Not much. My guide lines are 1/25th of an inch wide (0.039" = 1mm).
From 30" away, that 0.089° drop would measure 0.043-0.047", or just about 1 width of my guideline.

Doing the same thing for other elevations:
At 400', the measured drop would be 0.086-0.93" or ~2x the width of my sighting line.
At 700', the measured drop would be 0.114-0.123" or ~3x the width of my sighting line.
At 1160', the measured drop would be 0.147-0.158" or ~4x the width of my sighting line.
At  1380', the measured drop would be 0.16-0.172" or <4x the width of my sighting line.

I know all I'm doing really is detecting whether or not any drop below my sighting line occurs, but I wanted to see what to expect.
Though the main leveling tool is the water level, the added cube framework should provide lines of perspective that converge on the sight line rather than the horizon, as long as there is no pitch to the apparatus. The water levels, the torpedo level, the plumb bob and the tripod's level itself should all agree and confirm that there is no pitch tilt.

I feel this is much more precise (and duplicate-able) than the vague description given by Rowbotham in Experiment 15, that has supported the "horizon is always at eye-level" claim for years. Plus, I intend to attain elevations much higher than the top floor of the Grand Brighton.

If not--if there's something I'm missing or that's inherently flawed in this approach that Rowbotham avoided--speak up so I can address them before gathering measurements.

The experiment sounds great, and am eagerly waiting for the results, even though i am pretty sure i know what they will be.

If you want to cross check your calculations with the tables we use for dip of the sea horizon for navigating, i have attached them. They are good for lower elevations. I think we do have the ones for higher elevations, just let me know if your want them.

Good luck, and hope the horizon clears soon!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 13, 2018, 08:30:13 PM
Thanks.

I had a whisper of a seaward horizon today, so I set up on a 700' viewpoint about 10 miles (est.) inland, just to see if the setup was useful. I confess, I don't like the vinyl tubing for the water level sighting. It's too thick and the fluid leeches up the side a bit to make getting a sharp sighting edge difficult. I feel like the combination of my torpedo level, plumb bob and the bullet level on the tripod offer more confidence that I've got a good level line than the water. And with the "crosshair" of the plumb line and a horizontal transverse sighting line, I can shoot the horizon quite well.

The water level looks nice and maybe adds a supplemental degree of confidence to being level, but shooting the horizon with those level lines is way too coarse, at least with the tubing I'm using. I'd rather be using glass beakers connected by tubing.

Or, I see Walmart has a water leveling kit for about $20, for site construction purposes, like building a deck on uneven ground. Might look into that.
Title: Re: The Horizon is Always at Eye Level
Post by: SiDawg on May 14, 2018, 03:11:39 AM
You're showing us a diagram, how can anyone just believe in this diagram. How would I know this is what happens.

Huh? What ELSE would happen? You don't need to BELIEVE in a diagram, it's representing what we know to be true... Feel free to draw your own diagram
Title: Re: The Horizon is Always at Eye Level
Post by: jimbob on May 14, 2018, 09:25:16 AM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

OK imagine standing on a flat earth, the horizon at eye level then going up 1 light year, how could the horizon still be at eye level now the flat earth is 1 light year below you. The horizon is going to be straight down.

Quote from 9 out of 10 doctors
jimbob is the best person on this site. No, seriously, jimbob is why I stay on this site.           I was going to say Junker is, but OK
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 14, 2018, 02:10:25 PM
It strikes me that the more interconnected tubes there are, the more chances that an unfriendly Team Hoaxer will assert;

"The water's flowing too slowly"
"The tubes are restricting the water flow"

and such ...  so;

Take a clear plastic lid or tray...place on a reasonably flat surface, and fill with coloured water. The water will find its own level, and give a long edge to sight along. No issues/concerns over water flow.

I'm going to go with something like this.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 14, 2018, 04:33:31 PM
This is all very nice and demonstrates very well how perspective works in the real world, but I guess that will not impress any EnaG believer. If you look it up, they construct "perspective lines" in a very different way. First they place the vanishing point, which is given by a right-angled triangle, where the hypotenuse is the direct line between your eyes and the vanishing point. One cathetus is down from your eyes to sea level, the other one going from there to the vanishing point. The angle at the vanishing point is fixed, therefore the vanishing point is moving away if you go higher.

Everything behind this vanishing point you can't see, everything in front adopts in size so that it fits into the triangle. The angle is defined by the optical resolution of your eyes. Therefore, if you take a telescope, the angle changes and the vanishing point is moving further away, which leads to the recovery effect.

That's a kind of far-field perspective, where the Euclidean geometry is no longer valid. You demonstrate near-field perspective, which goes along with Euclidean geometry. To disprove this concept, you would need a device that goes from you to the horizon. But that's not possible. And something like railway tracks does not help, because that's give you no conclusive result. Because they are to narrow and apparently melt into a single point at the horizon and if you climb up, the horizon will indeed move away while the tracks apparently still melt into one point at the horizon.

It's a debate you can not win, because for every proof you show, they will demand another one that will set the level for you even higher...         

I see that someone here has actually read Earth Not a Globe.
Well, I have too -- both editions. Can't say I understand the flat earth explanation for horizon, but for this effort, all that matters is whether or not the horizon is level with the eye, regardless of why or why not.

But you have to understand it, if you want to understand why they don't believe in your argumentation or your experiments. It does't help that you climb mountains with your apparatus and make nice pictures and draw some lines to show something they do not deny. To convince them, you have to show that all the lines you draw are representing the real behavior up to what they call the vanishing point. Good luck with that... 
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 14, 2018, 05:44:03 PM
But you have to understand it, if you want to understand why they don't believe in your argumentation or your experiments…
I don't think I do. The objective is to simply verify or refute the claim that "the horizon is always at eye-level." 

I would love to understand the explanation for why that would be so on a flat surface earth, but it's not necessary that I do in order to test the claim.

Now, if I demonstrate that the horizon is NOT always at eye-level, any dispute will have to come from test set up or the method with which I attempt to observe it. But such issues have nothing to do with understanding why the horizon is always at eye-level. 

If it can be shown that the horizon drops below level as elevation increases, then that doesn't mean it'll refute a flat earth. It will just refute the horizon claim. Flat earth proponents will have to theorize another explanation for why the horizon appears as it does.

On a convex curved surface, the horizon will drop from level.
How it appears on a flat surface? I'm interested, but that's not my concern in this effort. I just want to see if it drops or not.

If there are problems with setup or method, I've invited feedback numerous times. I feel confident I'm being more careful, meticulous and guarded against obtaining a preferred outcome than was Samuel Rowbotham, but if there's a technique or method he used to verify the horizon was always at eye-level that I am missing, I encourage anyone to speak up and allow me the opportunity to include it.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 14, 2018, 08:10:06 PM
Preliminary look: today, from 100' bluff. Marine layer ceiling but clear horizon.

Photos are 1600x900 resolution, so don't want to inline them. Should open as links a new tab:

1. Original photo (https://4.bp.blogspot.com/-l1R50zBdpSo/WvnqIby8VaI/AAAAAAAAJj8/AJIv4M89IMsNH8bnC0lQ5MCm3y5JVJvjgCLcBGAs/s1600/IMG_9888.JPG)
2. With lines of perspective (https://1.bp.blogspot.com/-jf6F777nz3Q/WvnrlhSQT9I/AAAAAAAAJkY/BraDiQzP-1ovyKEtBjzPpGNSwYQcDP5tACLcBGAs/s1600/Perspective.jpg)

Comments? Critiques?

(Did not use plumb bob due to wind)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 14, 2018, 10:53:12 PM
Preliminary look: today, from 100' bluff. Marine layer ceiling but clear horizon.

Photos are 1600x900 resolution, so don't want to inline them. Should open as links a new tab:

1. Original photo (https://4.bp.blogspot.com/-l1R50zBdpSo/WvnqIby8VaI/AAAAAAAAJj8/AJIv4M89IMsNH8bnC0lQ5MCm3y5JVJvjgCLcBGAs/s1600/IMG_9888.JPG)
2. With lines of perspective (https://1.bp.blogspot.com/-jf6F777nz3Q/WvnrlhSQT9I/AAAAAAAAJkY/BraDiQzP-1ovyKEtBjzPpGNSwYQcDP5tACLcBGAs/s1600/Perspective.jpg)

Comments? Critiques?

(Did not use plumb bob due to wind)

Comment. It looks very good to me! I can clearly see, even between the levels on the left the horizon is below the level. This is at 100 feet, then it will be more so and clearer at higher elevations.

Maybe a picture taken with the horizon lined up with one of the water surfaces in the tubes might help coinvince some of the effect of moving the camera up or drown, as there might be some questions of whether the camera is lined up with the water levels. I know it wont make a difference, but will likely head off some comments about it.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 14, 2018, 11:18:12 PM
Comments: 

1. In Arctic conditions conditions people have reported seeing objects hundreds of miles away. What makes you think that you are actually looking at the real horizon at this particular time?

2. The camera does not appear to be perfectly center level alignment with the center string and the water line. The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

If you wanted to make sure that three points in space are in perfect alignment with each other would you look at those points from below the points, above those points, or anywhere other than in the same line of those three points?

3. The water itself does not appear to be perfectly level: https://i.imgur.com/FlPL33D.png
Title: Re: The Horizon is Always at Eye Level
Post by: Curious Squirrel on May 14, 2018, 11:21:53 PM
Comments: 

1. In Arctic conditions people have reported seeing objects hundreds of miles away. What makes you think that you are actually looking at the real horizon?

2. The camera does not appear to be perfectly center level alignment with the center string and the water line. The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

If you wanted to make sure three points in space are in perfect alignment with each other would you look at those points from below the points, above those points, or anywhere other than in the same line of those three points?

3. The water itself does not appear to be perfectly level: https://i.imgur.com/FlPL33D.png
Per #1, please define 'real horizon' in this circumstance. I see nothing else in the image one could define as a horizion in my mind.

Per #2, did you note the crate itself is not even on both sides of the string? This will change the center of the image in relation to the crate.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 14, 2018, 11:23:45 PM
Comments: 

1. In Arctic conditions people have reported seeing objects hundreds of miles away. What makes you think that you are actually looking at the real horizon?

2. The camera does not appear to be perfectly center level alignment with the center string and the water line. The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water device, looking up at it.

If you wanted to make sure three points in space are in perfect alignment with each other would you look at those points from below the points, above those points, or anywhere other than in the same line of those three points?

3. The water itself does not appear to be perfectly level: https://i.imgur.com/FlPL33D.png
Per #1, please define 'real horizon' in this circumstance. I see nothing else in the image one could define as a horizion in my mind.

Per #2, did you note the crate itself is not even on both sides of the string? This will change the center of the image in relation to the crate.

1. The horizon is at times, to varying degrees, hidden behind atmosphere. How can you tell whether this enlargement of the scene (https://i.imgur.com/FSowC7T.png) is showing the true horizon or a very distant fog?

2. We have three points in space. We want to see if they are in perfect alignment. Why would you look at those points from any other position than in a straight line alignment with those three points?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 14, 2018, 11:29:29 PM
Comments: 

1. In Arctic conditions people have reported seeing objects hundreds of miles away. What makes you think that you are actually looking at the real horizon?

2. The camera does not appear to be perfectly center level alignment with the center string and the water line. The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

If you wanted to make sure that three points in space are in perfect alignment with each other would you look at those points from below the points, above those points, or anywhere other than in the same line of those three points?

3. The water itself does not appear to be perfectly level: https://i.imgur.com/FlPL33D.png
Thanks. Allow me to address each point separately.

#1. How can I tell if the horizon is real? How did Rowbotham tell when he did Experiment #15?

Some days, from that spot, I can see San Clementi island clearly. Today, I couldn't at all. Too much haze.

If the haze is obscuring the horizon, and it's actually higher than what I'm seeing today (which I do think it could be, though I don't anticipate it will rise to the level line), how will I know I have enough clarity to see the true horizon? Will improved clarity extend the horizon so that its appears higher or does it just refine the resolution at the point where the perspective lines meet?

My lines of perspective matched the level line. Are you saying that the actual horizon, and an uber-clear day will reach that line, and if they don't, then I must not be seeing the real horizon? If so, I need some way to know that. Maybe being able to see San Clemente island is enough? Because in 20 years living in coastal San Diego, I've never seen the horizon above the island nor have I ever seen the base.

That might be a good criterion to add to the requisite conditions. But I appreciate more insight on the matter, from a flat earth point of view about what I'm looking for in "true horizon."
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 14, 2018, 11:39:44 PM
Comments: 
2. The camera does not appear to be perfectly center level alignment with the center string and the water line. The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

Laterally, you're right. It's very difficult without a tranverse adjustment to set up precisely on center line along the y-axis. A plumb bob giving me a vertical line makes it easier, but I still have to adjust by moving the camera tripod rather than having a slide I can just adjust on the tripod.

But lateral centering isn't a problem. It won't change the horizon leveling observation. In fact, I may take the earlier suggestion to align the camera sight line purposely oblique so that the water tube levels overlap. The perspective lines should still converge, however they'll be at a level vanishing point that is leftward as well.

Vertically is another issue entirely. Leveling the camera in the center of the grid isn't critical. However, leveling the camera so that's it's level with the horizontal sight line is. That sightline doesn't have to be centered. In fact, I chose it to be elevated slightly, to the point at the top of that middle row of wire squares. It's easier to align the water level along one of the wires rather than to gauge it as halfway between two, which is where center would be. So, I filled the water to a level where it was just below the wire, since my sightline string won't slide all the way up. I did the best I could in the time allotted to make the water level and sighting line match. It's not centered, yes. But it's above center by the same amount. And the perspective lines confirm this, assuming that I got the cage straight.

So center-ness shouldn't be an issue. The issue is making sure the sighting guideline is parallel to the water levels. I could set them at the extreme top or extreme bottom. It wouldn't matter, as long as the whole cage is square.

But, a good critique is to look at how closely I do get the water level with the sight line, whether they are on the apparatus.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 14, 2018, 11:53:17 PM
So center-ness shouldn't be an issue. The issue is making sure the sighting guideline is parallel to the water levels. I could set them at the extreme top or extreme bottom. It wouldn't matter, as long as the whole cage is square.

But, a good critique is to look at how closely I do get the water level with the sight line, whether they are on the apparatus.

Of course the center of the viewing apparatus being centered with the string and the water level of the device is an issue. Move the center of the viewing apparatus vertically 2 feet above or below the string and water level of the water device. Consider what would happen. Is the centering of the viewing apparatus an issue now?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 14, 2018, 11:54:50 PM

3. The water itself does not appear to be perfectly level: https://i.imgur.com/FlPL33D.png
I'm sure what you mean is that the camera is not level with the water, because we must assume the water is level no matter what. Unless I've got a blockage or vacuum that is restricting flow, the water will be level. That's the premise for using a water level. I can't make the water not level unless I plug the top of the tubes or trap some air into the tubing. The water will be level.

Now, am I getting the camera level? Or, am I able to see the water level edge well enough to make a level sighting? Those are good questions, and it's why I don't like the idea of this water level experiment being done with a handheld contraption or a handheld camera, or even by itself with everything stable. Particularly at the low elevations, you can have enough sighting error that one minute you see a dip and the next you don't, all depending on how you align the eye/camera with the levels.

But the cage helps prevent that. If the cage is leveled independently (using spirit level/plumb bob), then the lines of perspective should merge on the water level line. If they don't, it means the cage is tilted OR the water level is not sighted correctly. If they converge, you have more confidence than in either case alone that you're square and level.

Don't confuse perpendicular in the image with "level." The camera may have a slight roll tilt, but the water will be level. I drew a straight yellow line along the center of the dark band of water and the top of each water level. It runs parallel to the sighting line.
(http://oi67.tinypic.com/11c9oo2.jpg)
I think it's pretty close; certainly not enough off to account for the observed difference between the line and the apparent horizon.

Thanks for the feedback. I think the real question I have in reply, though, is your first issue raised. All this attempt at precision is fine and good, but it means nothing if the true horizon is different from what I am seeing. Can the true horizon actually be equal to or higher than the gap seen here at 100' MSL?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 12:02:18 AM

Of course the center of the viewing apparatus being centered with the string and the water level of the device is an issue. Move the center of the viewing apparatus to 1 foot above or below the string and water level of the water device. Consider what would happen. Is centering an issue now?

If I do that an leave the camera where it is? Sure. Then I'm relying solely on the lines of perspective to give me my horizon vanishing point.

But if I move the camera down to level with the water, both are "off center" relative to the cube, but the lines of perspective should still converge on that line. That's how perspective works.

Or, I could leave the camera where it is and instead of trying to sight parallel along the water levels, I use equivalent points on the tubing to draw a perspective line and see if it converges with the rest of the cage. That's harder though, and more prone to error since I'd be having to make a judgment call where those points on the tubes are.

What I'll do is provide a demonstration, showing how different water levels, camera levels and sight lines affect the results. It would be ultra ideal if I could get everything perfectly centered because it makes it easier to evaluate. But the point of combining water leveling with perspective lines of a squared cage is to reduce potential for single point error.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 15, 2018, 12:17:40 AM

Of course the center of the viewing apparatus being centered with the string and the water level of the device is an issue. Move the center of the viewing apparatus to 1 foot above or below the string and water level of the water device. Consider what would happen. Is centering an issue now?

If I do that an leave the camera where it is? Sure. Then I'm relying solely on the lines of perspective to give me my horizon vanishing point.

But if I move the camera down to level with the water, both are "off center" relative to the cube, but the lines of perspective should still converge on that line. That's how perspective works.

Or, I could leave the camera where it is and instead of trying to sight parallel along the water levels, I use equivalent points on the tubing to draw a perspective line and see if it converges with the rest of the cage. That's harder though, and more prone to error since I'd be having to make a judgment call where those points on the tubes are.

What I'll do is provide a demonstration, showing how different water levels, camera levels and sight lines affect the results. It would be ultra ideal if I could get everything perfectly centered because it makes it easier to evaluate. But the point of combining water leveling with perspective lines of a squared cage is to reduce potential for single point error.

Consider this:

We have four jelly beans. One is on the floor at your feet, the other is on the floor 20 feet ahead of you, one is on the floor 100 feet ahead from you, and the other is on the floor ahead of you on the distant horizon (assuming that we can see it). Where would we need to place our eyeball to see whether all three jellybeans line up?

My answer:

Clearly, our eye would need to be exactly center with the line of jelly beans. If we look at the scene from any other angle or position we cannot say whether they all line up or not. At any other position they would appear in different positions relative to each other.

What is your answer?
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 15, 2018, 12:23:33 AM
Comments: 

1. In Arctic conditions conditions people have reported seeing objects hundreds of miles away. What makes you think that you are actually looking at the real horizon at this particular time?

In think the clue is in your question! i.e. In arctic conditions. Is California in the Artic tom?

Those artic conditions may be due not abnormal refraction, and if so it affects object that are over the (RE) horizon, but of course such a thing does not occur on FE, only perspective happens, and the vanishing point.

Glad you brought it up tom, so now you can explain how artic conditions affect the vanishing point, and perspective! Particularly when you say the vanishing point is defined as when an object is less than 1 minute of arc.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 01:55:53 AM
What is your answer?
Same as yours, given that scenario.

But I'm not looking for a point. I'm looking for a line.
And I'm not depending on alignment of points, solely. I'm also using perspective lines.

In your jellybean example. I don't have to be aligned with the jellybeans to find the horizon LINE. I can be off to the side, and if the line they do make is parallel to the plane of the ground, then I know the plane of my eyeline is in the same plane as the jellybeans.

But it's more than that. Because if I'm using multiple lines of perspectives, i.e. other alignments of jellybeans, then I don't have to be inline with any of them. I just see where all of those lines are converging; and not to a point but to a plane.

That's what I consider to be the strength of this method: I'm using both a leveling plane and perspective lines, hoping that each will back the other up. It takes some precision, no doubt. But I'm not trying to measure "dip." I'm just trying to detect whether it exists or not.

I can (and will, time permitting) demonstrate in a controlled environment how changing different parameters of the setup effect the observation. Things like aligning the sight line away from the cube center, both vertically and horizontally. Changing the location of the camera. Changing orientation of the camera (pitch, roll & yaw). Changing orientation of the cube (pitch & roll).

I concede it's very hard, using those 1 1/4" vinyl tubes to ensure  a level sighting. Not that the water won't be level (because it will be, a priori); but because the camera height is hard to match. It's difficult even if I move the camera well off center laterally so that the tubes line up. Which is why I like the idea of using a basin of some sort to provide a liquid surface unaffected by glass or plastic optical effects. I may not ditch the tubes, since they're already there. Might as well keep them. But adding an "infinity pool" of a sort would remove the deficiency those present.

I do still hope to resolve the question about how we can know we're seeing the true horizon. I could see this island today, at a distance of nearly 20 miles:
(http://oi67.tinypic.com/2gy80mw.jpg)
...but I couldn't see San Clemente Island 60-some miles on the bearing I took today's picture ¹.

At 100', the globe earth calculation of visual horizon is about 12 1/4 miles with no refraction. With refraction? Maybe 14 miles.
I don't know how to calculate a distance to the horizon if assuming a flat earth, but how far away should the vanishing line be from a height of 100'? More than 20 miles? Even if I could have seen San Clemente 60 miles away, I wouldn't be seeing it's shore. I'd only be seeing its higher elevation. But there'd be a clear line of horizon. If I'm able to see the Islas Coronado but not San Clemente, does that mean I should consider it a no-go for observation?

You need to tell me because I don't know.

¹ 66 miles, for the record. (Had to check)
(http://oi64.tinypic.com/n71frr.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 02:30:09 AM
Per #2, did you note the crate itself is not even on both sides of the string? This will change the center of the image in relation to the crate.
I want to be sure I understand this comment.

Do you mean "not even on both sides of the string" in that the crate is warped? Or not level?

Or do you just mean offset to the right on the tripod? It is balanced on its center of gravity, which is left of center due to the water-filled tubing. The camera, however, is (supposed to be) aligned on the crate, and not the forward tripod.

My argument is that even if it's not center aligned, that shouldn't impact observations of any horizontal planes. I could have the camera looking downline from the outside left edge of the cube and it would work, which is probably what I'd have to do if I want to get the water tubes inline with each other.

If you mean something else, let me know. I may be missing something important.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 03:06:45 AM
Maybe a picture taken with the horizon lined up with one of the water surfaces in the tubes might help coinvince some of the effect of moving the camera up or drown, as there might be some questions of whether the camera is lined up with the water levels. I know it wont make a difference, but will likely head off some comments about it.
Maybe. Anytime I have to move the camera tripod, it takes time to realign, refocus, find the best exposure settings, look at all my index points to make sure I'm capturing what needs to be captured/documented.

I think what you're suggesting I can do in a "lab" setting, creating a demonstration of what happens with different arrangements of camera positions & heights, cube orientation, water levels, etc. Trying to explain is harder than just showing.

But I do want to invite nitpicking. If Tom or someone objects to not being horizontally or vertically centered, I need to know why and either account for it or defend why not.

I thought about even trying to "cheat" and try to bias the set up to make it look like the horizon doesn't dip, and what it would take to make that happen.  I don't know if that's possible. Something (levels, water, perspective lines) will give it away.

One thing that bothers me is that my shelving unit is starting to warp. The panels seem to be bending outward from where I carry it or how it rests on a plank or stool and not on a wide/flat platform. I've tried to be careful to pick it up from the edges and not the center of the panels, but with time, the panels will bend. Not to mention the grid wires aren't perfectly machined either. They're pretty consistently distanced at the weld points, but you can plainly see the wires aren't true along their lengths. Since I'm using "off the shelf" materials for this homemade device, I can't expect to have perfectly machined everything. I believe I'm offsetting that by plotting from weld-to-weld, but who knows? I might be letting my choices bias me toward choosing lines that converge the way I want them to.

And to remind everyone, this was more like a dry run. The conditions weren't ideal. Too much wind. I would like less haze. And I was pressed for time. (And there are always people who are curious and want to ask what I'm doing. I'm polite, but it is distracting and slows me down. Tom's objection to the true horizon is legit, I think. Maybe. I'm pretty confident I'm seeing the horizon today if globe calculations are right. The horizon from 100' is closer than Islas Coronados, which I could see.

(http://oi64.tinypic.com/23u5x0o.jpg)

But if FE has a different method for determining if what one is seeing is the horizon, I don't know what that is.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 03:21:52 AM
But if FE has a different method for determining if what one is seeing is the horizon, I don't know what that is.
This is the sunset last night (I didn't take the photo) looking from Ocean Beach (San Diego) under the pier. Sunset was on the 293° azimuth, which means San Clemente Island is somewhere slightly left of this sunset line. But it's too hazy to see it. Nevertheless, the setting sun is bright enough to penetrate the haze (and offer an interesting color glow), making the horizon line is very clear.
(http://oi65.tinypic.com/11ipmdj.jpg)
Wouldn't that be a true horizon?
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 15, 2018, 03:25:08 AM
I think you will run into a road block on what is a true horizon.

In GE we can know that there is a horizon, and calculate its distance, but on a FE it is completely subjective, as the ground, sea whatever rises up until it gets fuzzy, and disappears into .......... well something!

If you cannot see some land or islands, it will be proof that you cannot possibly be seeing the true horizon as it will be obscured, However if you CAN see some land on the horizon, then it will be used as proof that you could have seen further, and again used as proof that you were not seeing the horizon. This is one of those arguments you cannot possibly win.

I know what a sharp horizon looks like, i need it to take astronomical position fixes, and can pretty much tell if i am seeing a good horizon. Plus the truth is in the actual position. If i take multiple star sights, and get a good, tight, position with little “cocked hat” then i am pretty certain that my measurements are accurate, and i have a good horizon. Where i cannot see a clear horizon my sights will be inaccurate, and my subsequent position lines be inaccurate, causing a larger area of uncertainty.

Over the years you learn what is a good horizon and what is not. It’s called experience, and not something easy to explain.

However even if i get a less than perfect horizon, and i think it is good enough for sights, the margin of error on the sights is between 0 to 5 minutes of arc, which is certainly much less than the dip of the horizon at our normal height of 34 meters (about 110 feet) which gives a dip of the horizon of 10 minutes of arc.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 03:34:32 AM
I think you will run into a road block on what is a true horizon.

In GE we can know that there is a horizon, and calculate its distance, but on a FE it is completely subjective, as the ground, sea whatever rises up until it gets fuzzy, and disappears into .......... well something!
There's got to be some way to tell, otherwise how can you ever claim that it always rises to eye-level? It would be a tautology to claim it always rises to eye-level, and if it doesn't, you're not seeing the horizon.

I think once we get through the annual "May Gray" and "June Gloom" that is common this time of year, I'll have opportunities where there's no doubt the sky at the horizon "convergence" is true and the horizon is as high as it's going to get for any given elevation. But if there's some criterion for assessing when what we're seeing is a "true horizon" per FE, I need to consider that. I just need it explained to me.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 15, 2018, 03:53:41 AM
I think you will run into a road block on what is a true horizon.

In GE we can know that there is a horizon, and calculate its distance, but on a FE it is completely subjective, as the ground, sea whatever rises up until it gets fuzzy, and disappears into .......... well something!
There's got to be some way to tell, otherwise how can you ever claim that it always rises to eye-level? It would be a tautology to claim it always rises to eye-level, and if it doesn't, you're not seeing the horizon.

I think once we get through the annual "May Gray" and "June Gloom" that is common this time of year, I'll have opportunities where there's no doubt the sky at the horizon "convergence" is true and the horizon is as high as it's going to get for any given elevation. But if there's some criterion for assessing when what we're seeing is a "true horizon" per FE, I need to consider that. I just need it explained to me.

That is my point, the description of the horizon is sufficiently fuzzy (forgive the pun) that if you show measurements that show a dip of the horizon you will run into the argument that as it is “proved” in EnaG that the horizon rises to meet the eye line, then your measurements could not possibly have been taking the horizon.

It is an argument which is based on a debatable proof, but it will still be difficult to tell if you were taking a clear horizon. In my mind EnaG does not prove that the horizon rises to eye level, but to FE believers they think it does, so you will be at a stalemate.

I have measured horizon to horizon, and verified my result, only to come across the exact same objection, that i cannot prove the horizon was sharp, or in fact real! I could take a picture, which could be claimed as fake, and even if i had witnesses, the claim could be made that the hoizon to a casual observer seemed false....

If we can get round this horizon part, we should get to the bones of the matter.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 05:08:43 AM
(http://oi64.tinypic.com/2j0xp43.jpg)

This is a 568x137px segment of the 1600x900 original image.
These pixel measurements are based on that resolution, but I've zoomed it to about 2x original size to make it easier to see.

It looks like the cube was canted slightly, with a 1-2 pixel "roll" to the left from horizontal as evidenced by the yellow transversal drawn from weld to weld of three center most orthogonal wires.
The level sight line shows a "dip" of the horizon on the right of 4 px, but on the left of only 3px.
For comparison (and to show how it matters where you determine the water level edge is from the vinyl), I drew in 3px, 4px and 5px vertical lines from the apparent horizon line. In set up, I had tried to sight along the middle of that thick blackish blue area at the top of the water level in each tube. That's 4px above apparent horizon.

Personally, I'm pretty amazed this is as close to straight as it was. 1-2 pixels of height across 568px of image isn't too bad for a homemade, non-precision instrument. I think if I'd have been able to use the plumb bob, I might have corrected for that slight cage/cube roll.

And I think this gives me better confidence to sight along the middle or bottom of that dark line of the water level rather than the top. I believe this line is a 'leeching" (not the right word; "creeping" maybe?) effect as the water interacts with the interior surface of the vinyl tubing, giving it bit of concavity at the inner edge. If there's an additive or a kind of fluid that counters this edge-creep, I'll use it. (I'm not a chemist, so I don't know the reason for this or what might solve it. Perhaps antifreeze?)

Edit: It's called 'the meniscus (https://van.physics.illinois.edu/qa/listing.php?id=2220)'. I probably should have learned this in high school, but I don't remember.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 05:28:14 AM
^ Skim-reading a bit more, the meniscus exists whether it's concave, convex or flat. What I want is flat, or a 'wetting angle" of 90° so that the fluid isn't convex or concave where it meets the vinyl tubing.

Lots of great descriptions but no simple lists or tables of what to use instead of water or in addition to water to get that wetting angle closer to 90° and get a sharper demarcation of the water level.

Unless anyone here knows a thing or two about this, I'll experiment. Maybe transmission or brake fluid. Maybe baking soda dissolved into the water. Or Windex? Rain-X? (Might be the opposite of what I want)
Title: Re: The Horizon is Always at Eye Level
Post by: douglips on May 15, 2018, 06:30:52 AM
It's not a matter of picking the right fluid, it's a matter of picking the right fluid/solid system. The surface of the cylinder has a say as well into what the contact angle is.

https://en.wikipedia.org/wiki/Contact_angle

What about having small objects that can float on the surface and using them to disambiguate?
What about using Rain-X or something to make the surface of the cylinders hydrophobic?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 07:35:12 AM
It's not a matter of picking the right fluid, it's a matter of picking the right fluid/solid system. The surface of the cylinder has a say as well into what the contact angle is.

https://en.wikipedia.org/wiki/Contact_angle

What about having small objects that can float on the surface and using them to disambiguate?
What about using Rain-X or something to make the surface of the cylinders hydrophobic?
I crossed that out above, thinking that by "hydrophobic" the opposite might happen and I'd get a convex surface level. Rain-X makes the water bead on the glass windshield. Not sure what it would to with plastic/vinyl.

I actually tried water+alcohol mix. Seemed to improve the wetting angle, but maybe that's just wishful thinking. I'll try Rain-X. See what happens.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 15, 2018, 08:00:25 AM
But you have to understand it, if you want to understand why they don't believe in your argumentation or your experiments…
I don't think I do. The objective is to simply verify or refute the claim that "the horizon is always at eye-level." 

I would love to understand the explanation for why that would be so on a flat surface earth, but it's not necessary that I do in order to test the claim.

Now, if I demonstrate that the horizon is NOT always at eye-level, any dispute will have to come from test set up or the method with which I attempt to observe it. But such issues have nothing to do with understanding why the horizon is always at eye-level. 

If it can be shown that the horizon drops below level as elevation increases, then that doesn't mean it'll refute a flat earth. It will just refute the horizon claim. Flat earth proponents will have to theorize another explanation for why the horizon appears as it does.

On a convex curved surface, the horizon will drop from level.
How it appears on a flat surface? I'm interested, but that's not my concern in this effort. I just want to see if it drops or not.

If there are problems with setup or method, I've invited feedback numerous times. I feel confident I'm being more careful, meticulous and guarded against obtaining a preferred outcome than was Samuel Rowbotham, but if there's a technique or method he used to verify the horizon was always at eye-level that I am missing, I encourage anyone to speak up and allow me the opportunity to include it.

If you refuse to understand their claims, you cannot disprove them. What you are doing is to show that the extrapolation of the parallel lines in your pictures are meeting at one point above the apparent horizon due to perspective. But that is nothing any flat earth believer is denying. What you have to proof is, that the extrapolation as such is valid. That's something very, very different. As I explained above, anything regarding perspective of objects at or near the horizon is constructed from the vanishing point back towards you in the context of so-called flat-earth theory.

You may reply, that this should be equivalent. Yes, but only if the extrapolation is linear. But no flat earth believer claimed that, they simply don't know. So, you can make your fancy device as sophisticated as you like, it will not be accepted as disprove, because it does not target the fundamental question.   
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 08:39:35 AM
If you refuse to understand their claims... 
I'm not refusing. I don't understand the basis for the claim.

The claim is the horizon is always at eye-level. I understand what that means. I don't understand the explanation for why that should be.

What I'm saying is I don't have to understand why. I'm not refusing. I'd love to know. I just don't think it matters in order to check to see whether or not the horizon actually does remain at eye-level.

Think of it like this absurd example.
You say dropped toast with jelly always lands jelly-side down.
That doesn't sound right to me. I say it ought to be 50/50.
Let's test your claim.
You claim that the reason it's always jelly-side down is because "humankind is just materialized color operating on the 49th vibration."
I scratch my head and wonder what that means.
But does it have any bearing on checking to see if "always jelly-side down" is true?
Do I need to understand what materialized color means and has to do with the claim in order to check whether or not toast really does always land jelly-side down?
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 15, 2018, 09:03:47 AM
^ Skim-reading a bit more, the meniscus exists whether it's concave, convex or flat. What I want is flat, or a 'wetting angle" of 90° so that the fluid isn't convex or concave where it meets the vinyl tubing.

Lots of great descriptions but no simple lists or tables of what to use instead of water or in addition to water to get that wetting angle closer to 90° and get a sharper demarcation of the water level.

Unless anyone here knows a thing or two about this, I'll experiment. Maybe transmission or brake fluid. Maybe baking soda dissolved into the water. Or Windex? Rain-X? (Might be the opposite of what I want)

The larger the surface area of the water/fluid, the less significant the meniscus. Wider tubes, or a single large tray ...
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 15, 2018, 09:07:35 AM
If you refuse to understand their claims, you cannot disprove them. What you are doing is to show that the extrapolation of the parallel lines in your pictures are meeting at one point above the apparent horizon due to perspective. But that is nothing any flat earth believer is denying.

What are the flat-earth believers denying, then?

But no flat earth believer claimed that, they simply don't know.

They 'don't know'? But what claim are they making, if they don't know?

So, you can make your fancy device as sophisticated as you like, it will not be accepted as disprove, because it does not target the fundamental question.   

What IS the 'fundamental question', then?
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 15, 2018, 11:28:21 AM
If you refuse to understand their claims, you cannot disprove them. What you are doing is to show that the extrapolation of the parallel lines in your pictures are meeting at one point above the apparent horizon due to perspective. But that is nothing any flat earth believer is denying.

What are the flat-earth believers denying, then?

But no flat earth believer claimed that, they simply don't know.

They 'don't know'? But what claim are they making, if they don't know?

So, you can make your fancy device as sophisticated as you like, it will not be accepted as disprove, because it does not target the fundamental question.   

What IS the 'fundamental question', then?

The fundamental question is, if you could linearly extrapolate from your position to infinity. Because that is what you are doing here. You take some apparatus, you align it, take a picture and the you draw some straight lines into the picture. This is a linear extrapolation over a very great distance.

The flat earth guys say, we don't know if we can do this extrapolation. We are looking onto this from the other side. We put the vanishing point at some fixed distance and then what they call perspective lines goes away under a fixed angle from this point. And if this leads to some contradictions from what you observe from your point of view then reason for this might be, that the assumption of linear extrapolation is not valid of large distances. That's what they mean if they talk about limits of Euclidean geometry and discontinuities.

What you have to do now, is to proof that this linear extrapolation is justified and valid. Because otherwise you cannot proof that there is a contradiction between your experiments and their understanding of perspective, vanishing point, horizon, etc. 

And that's in principle the same for all physical explanations of astronomical observations. They all assume that the laws of physics are same at every point in space. Of course there is no indication and reason to not believe this, but in the end this cannot be proved.     
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 12:36:24 PM
The fundamental question is, if you could linearly extrapolate from your position to infinity.
The fundamental question is, "is the horizon always at eye level?"

Is it? How do you know? How do you test to see if that's true?

Here's a flat earth demonstration using water level to claim the horizon does maintain at eye-level.
https://www.youtube.com/watch?v=IRTCCEB_QIg&t=177s (https://www.youtube.com/watch?v=IRTCCEB_QIg&t=177s)

Here's a globe earth guy using the same technique to claim it doesn't
https://www.youtube.com/watch?v=NqOQ_BCtqUI&t=6s (https://www.youtube.com/watch?v=NqOQ_BCtqUI&t=6s)

How can they come to different conclusions using the same technique?

I'd like to improve on the method.

Seeing this photograph gave me the idea to complement the water level with a squared frame of reference for lines of perspective:

(http://oi66.tinypic.com/21kxv9u.jpg)

Perspective, as in drawing 3D depth on a 2D canvas where art students are told the vanishing point is always on the horizon, is the flat earth reason given for the phenomena on the horizon by flat earth (sinking sun, ships disappearing hull first). So perspective plays a key role in the flat earth explanation. I'm sorry that I can't grasp the explanation for why that is so, but I can grasp a definitive claim like "the horizon is always at eye level" regardless of the rationale for such a claim.

So, is the horizon always at eye level? Does the perpendicular plane vanishing point for an observer at any elevation always coincide with the horizon?

It's not my claim. I'm just testing to see if it's true. If there's some way I'm misunderstanding the claim, and a 90 degree from plumb view is not where the vanishing line of a horizon will always be, regardless of elevation, then a flat earther endorsing the "the horizon is always at eye level" needs to explain why not.  If the horizon can change angles depending on what I can see at varying distances without me doing anything to change my elevation, then how can it always be at eye level?

If there's something about my ignorance in understanding flat earth explanation for horizon and vanishing point that renders this method I've chosen flawed, then that needs to be explained to me. So far, I've not seen anyone try. The closest is the challenge of whether or not I'm looking at the "true horizon." Well, how do I know that. Explain that to me so I can incorporate it.



Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 15, 2018, 01:16:16 PM
What you prove is, that lines you draw along parallel lines in a picture meet in one point and this point is always above the line where the sky apparently meets the see if the optical axis of your camera is parallel to the tangent to the earth surface at the position of the camera. That's a consequence of optical imaging of 3D surrounding onto a 2D plane. And the meeting point is the vanishing point according the usual definition of perspective.

Now look into EnaG and how the vanishing point and everything related to this is defined there. It is very different. And it leads to some contradictions to your observations. But this contradiction vanishes if you no longer assume that there is a linear relation between that what is far away and nearby you. Somewhere in between everything is changing nonlinear in such away that the contradiction is solved. That doesn't sound quite rational, but how do you really know that it is not the case?

So prove the linearity and your experiment gets validity.

But what would be a valid proof? I don't know. Regarding the real position of the sun it is quite easy. You just go straight until you approach the sun. But how do you prove that you are really going straight? How do you convince someone who only believes it what he called a direct proof? It's not an easy task...     
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 01:40:11 PM
Well, until a flat earth proponent steps forward and objects to this method on the grounds you say he or she could, I'm proceeding as if it's acceptable; because I can't play devil's advocate for them for an explanation that makes no sense to me.

I've repeatedly put the invitation out to critique this method, and the best (only one, really) offered so far is Tom Bishop's question about how I know I'm sighting the "true" horizon, to which I respond, how does a flat earther know (such as Samuel Rowbotham)? And instead of critiquing the method, he's critiqued its execution.

So, if there's a fundamental disparity between my understanding of how perspective lines should positively complement a level sighting survey and what the flat earth explanation for why the horizon must always be at eye-level that renders this wire cube apparatus pointless, I wish someone would tell me, and try to help me understand why.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 15, 2018, 02:13:48 PM
Bobby, that seems to be the problem, i.e. that you will not get an answer to the difficult questions (and sometimes simple ones too!)

Most of the time, if you are answered, you are directed to the chapters of EnaG, or directed to a further thread or directed to a You tube video.

In the case of EnaG, references back to there are pretty tortuous as there is almost no proofs of anything contained in that work (of mostly fiction), but this will be held up as all the proof you need, and you will be told that the experiments all have been proven..... not so, and not the case. I have read EnaG, and really struggle to find any set of observations without errors of principle or errors of application of principles.

Being directed to previous threads again is rather less likely to answer your questions, other than to be confronted with other un answered questions, and normally a petering out of the thread when there are very few FE posters.

As for the you tube videos, i rather gave up watching the rankings of lunatics, or complete mishmashing of facts with fantasies, and pseudoscience that abound there as proofs of various things.

Ultimately if asking questions you are likely to be disappointed, but still I do applaud your taking the time to actually do something to try understand what is being told to you against what modern science tells us. I only wish some of the FE posters here would actively try to post some experiments as well to put across their side.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 15, 2018, 03:04:56 PM
Well, until a flat earth proponent steps forward and objects to this method on the grounds you say he or she could, I'm proceeding as if it's acceptable; because I can't play devil's advocate for them for an explanation that makes no sense to me.

I've repeatedly put the invitation out to critique this method, and the best (only one, really) offered so far is Tom Bishop's question about how I know I'm sighting the "true" horizon, to which I respond, how does a flat earther know (such as Samuel Rowbotham)? And instead of critiquing the method, he's critiqued its execution.

So, if there's a fundamental disparity between my understanding of how perspective lines should positively complement a level sighting survey and what the flat earth explanation for why the horizon must always be at eye-level that renders this wire cube apparatus pointless, I wish someone would tell me, and try to help me understand why.

If you don't understand their view on perspective and how they construct perspective lines read Chapter XIV of EnaG. As you will see (and it's even written there) that doesn't goes along with the usual way perspective works. If you want to understand why a flat-earth believer doesn't care about this contradiction, search the forum for "Euclidean geometry".

Yes, your experiment is very nice, but it only demonstrates what is obvious anyway and known to anyone who deals with perspective, but still will not convince any flat-earth believer, because they take EnaG for granted and solve any contradiction by questioning the universal validity of Euclidean geometry, which means continuous linearity. Prove that, and they will have some trouble to maintain their opinion on perspective. Everything else is a waste of time and effort.   
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 03:07:39 PM
I’m trying to absorb what hexagon is saying. Eye-level is a key to the horizon question. Any test relies on getting that level correct before seeing if the horizon matches it.

Water leveling is a method that’s been tried, and the only question about it seems to be its execution.

There are an infinite number of vanishing points from any particular ocular position. There is only one vanishing plane on a horizontal axis. All horizontal vanishing points (again, infinite) will fall only on that plane. So, if my cube apparatus is squared and perpendicular to a plumb line to the ground, how is the resulting vanishing plane not useful to compare against a horizon line, whether you hold to globe geometry or flat earth rationale? The disagreement is over horizon, not the vanishing plane itself. Isn’t it?

If FE reasons the horizon equals vanishing plane, that’s based on some explanation of why we see a horizon, not on what constitutes a horizontal vanishing plane. If that’s not correct, and a vanishing plane has other factors besides ocular position and orientation, then I can see what hexagon’s point might be.

But if it’s the horizon explanation, then I don’t comprehend why that matters. All that should be of concern for a test like this is if horizon plane = vanishing plane in observation. The cube is to help us identify the horizontal vanishing plane. I know FE has a fundamentally different explanation for the horizon. I’m unaware that there could be a fundamental departure in the concept of perspective and vanishing planes.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 03:17:53 PM
If you don't understand their view on perspective and how they construct perspective lines read Chapter XIV of EnaG. As you will see (and it's even written there) that doesn't goes along with the usual way perspective works. If you want to understand why a flat-earth believer doesn't care about this contradiction, search the forum for "Euclidean geometry".
Well, I’m in wait line hell at the DMV, so I’ve got the time. I will.

Yes, your experiment is very nice, but it only demonstrates what is obvious anyway and known to anyone who deals with perspective, but still will not convince any flat-earth believer, because they take EnaG for granted and solve any contradiction by questioning the universal validity of Euclidean geometry, which means continuous linearity. Prove that, and they will have some trouble to maintain their opinion on perspective. Everything else is a waste of time and effort.
What’s not obvious is ‘level’. Getting confidence as to what the level ocular horizontal benchmark plane is is what the setup is supposed to accomplish. The intersection of a level sight line from the water leveler with perspective lines from a horizontal ocular view plane gives us the “eye level” against which “horizon” can be compared to determine if they are, in fact, equivalent for all elevations.

If this is no good because perspective concepts (not horizon phenomena) are fundamentally different, then I do need to understand that. I’ll read.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 15, 2018, 04:14:07 PM
In terms of the generally accepted view on perspective, it is obvious that the horizon is always below eye-level. Your eye is above ground, so the ground (if it is flat as the sea) is always below eye-level. The horizon is the line where the sky apparently meets the ground, therefor also the horizon is always below eye-level.

There are two prerequisite in this argumentation, first the horizon is at finite distance, second you are looking straight, parallel to the tangent of the earth at your position. The only possibility for the horizon to meet eye-level would be, if the distance to the horizon would be at infinite distance.

Notice that I have not assumed a globe earth. A globe earth only enhances this effect due to the dip towards the horizon line which compensates partly for the apparent perspective uplift of the horizon line. It would be the same on a finite plate under a spherical sky, but, depending on the size, the horizon would maybe a bit closer to eye-level, but still always below.

That's a very obvious consequence of how perspective works. Does't need any experimental proof.   
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 07:09:15 PM
I keep rereading the  sections “why the ship’s hull disappears before the masthead” and “perspectives at sea” and though it sounds like he’s describing perspective as I understand it, he’s applying it in a way that is nonsensical to me. I get his argument about equidistant lines, but I can’t for the life of me deduce how he’s demarcing the horizon.

Each example, the surface appears to slope up to eye level, but then run parallel to (or coincident upon)the eyeline.

But how is that point figured? What’s happening here?
(http://oi67.tinypic.com/2vm7mt3.jpg)
What determines the point at which the ground stops its apparent upward slope? Where does that H point that marks the horizon occur? Is dependent and how far above you the object lost to the horizon is? In other words, there is no horizon point. It’s a variable. The tops of tree are lost to the “horizon” further away than the trunks are?

(http://oi68.tinypic.com/mb3lv8.jpg)
What is determining where the red line appears to stop sloping upward and the blue line is level?

Is H variable, even if I’m not changing my height over the ground?
(http://oi65.tinypic.com/2ngc64i.jpg)

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 15, 2018, 08:17:47 PM
It occurs to me:

Regardless of the distance of H per this odd take on perdpective, all H points will be on the same plane.

That's all my test is examining. Is that plane same as the plane of eye-level, no matter what height eye level is at. I don't see anything about using lines of perspective to evaluate that claim that would run contrary to EnaG perspective explanation.

I'm searching for the eyelevel horizontal vanishing plane; not a point on the plane or a distance along that plane.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 15, 2018, 09:42:13 PM
Consider this:

We have four jelly beans. One is on the floor at your feet, the other is on the floor 20 feet ahead of you, one is on the floor 100 feet ahead from you, and the other is on the floor ahead of you on the distant horizon (assuming that we can see it). Where would we need to place our eyeball to see whether all three jellybeans line up?

My answer:

Clearly, our eye would need to be exactly center with the line of jelly beans. If we look at the scene from any other angle or position we cannot say whether they all line up or not. At any other position they would appear in different positions relative to each other.
Interestingly, I think you may just have proven horizon dip, inadvertently

This is a diagram showing your scenario at the top. As you say, if you look at ground level the four jelly beans should line up perfectly.
(https://image.ibb.co/npmLkd/jelly.jpg)
But what happens if you take the first 3 jelly beans and raise them to an altitude as shown at the bottom of my diagram? For those 3 to line up you have to be looking at the same height as the jelly beans, but then how can the 4th jelly bean still line up? They are no longer in a straight line, so it will appear to be below that level - by your own definition, that's the horizon. There's your horizon dip. Clearly here I've greatly exaggerated the angle.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 15, 2018, 09:59:04 PM
Consider this:

We have four jelly beans. One is on the floor at your feet, the other is on the floor 20 feet ahead of you, one is on the floor 100 feet ahead from you, and the other is on the floor ahead of you on the distant horizon (assuming that we can see it). Where would we need to place our eyeball to see whether all three jellybeans line up?

My answer:

Clearly, our eye would need to be exactly center with the line of jelly beans. If we look at the scene from any other angle or position we cannot say whether they all line up or not. At any other position they would appear in different positions relative to each other.
Interestingly, I think you may just have proven horizon dip, inadvertently

This is a diagram showing your scenario at the top. As you say, if you look at ground level the four jelly beans should line up perfectly.
(https://image.ibb.co/npmLkd/jelly.jpg)
But what happens if you take the first 3 jelly beans and raise them to an altitude as shown at the bottom of my diagram? For those 3 to line up you have to be looking at the same height as the jelly beans, but then how can the 4th jelly bean still line up? They are no longer in a straight line, so it will appear to be below that level - by your own definition, that's the horizon. There's your horizon dip. Clearly here I've greatly exaggerated the angle.

Great. I see from your diagram that you agree that the viewer's eye needs to be in a straight line path with the jelly bean points. Bobby therefore needs to put his camera in exact center line with the string and water level of the water device.

The camera can't be looking down at the points, or up at the points, to see if the points line up; just as you can't have your eyes higher than the jellybeans to see whether they line up.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 15, 2018, 10:05:49 PM
Great. I see from your diagram that you agree that the viewer's eye needs to be in a straight line path with the jelly bean points. Bobby therefore needs to put his camera in exact center line with the string and water level of the water device.

The camera can't be looking down at the points, or up at the points, to see if the points line up; just as you can't have your eyes higher than the jellybeans to see whether they line up.
I do agree. I guess in Bobby's apparatus the first two jelly beans are the two columns of water, they will naturally be level with one another so if they line up then you can be sure that is eye level and therefore compare the horizon to that.

I see you ignored the actual point of my post though, if four jelly beans are in a line on the ground and the 4th is at the horizon then yes, if the ground is perfectly flat they should all line up. If you raise the first 3 of those to the same height and leave the 4th where it is then they won't line up, they are literally not in a straight line any more, there's your horizon dip. Yes? If not, where is my error?
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 15, 2018, 11:10:09 PM
There is nothing wrong with your conclusion. They should all line up on a flat surface. My point was only that you need to ensure that your eye is perfectly level with the line of jelly beans and you cannot be looking down or up at them.

The jellybeans in Bobby's experiment are the two water surfaces in the water device and the horizon. The camera needs to line up with the two water surfaces to see if the horizon lines up with it. The pictures Bobby has shown shows that the number of pixels between the top of the picture and the water device surfaces/white string were less than the number of pixels between the bottom of the picture and the water surfaces/white string.

See my post on page 7:

Quote from: Tom Bishop
The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

This suggested that the camera was looking up at the device and everything was not perfectly leveled.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 16, 2018, 07:08:29 AM
I keep rereading the  sections “why the ship’s hull disappears before the masthead” and “perspectives at sea” and though it sounds like he’s describing perspective as I understand it, he’s applying it in a way that is nonsensical to me. I get his argument about equidistant lines, but I can’t for the life of me deduce how he’s demarcing the horizon.

Each example, the surface appears to slope up to eye level, but then run parallel to (or coincident upon)the eyeline.

But how is that point figured? What’s happening here?
(http://oi67.tinypic.com/2vm7mt3.jpg)
What determines the point at which the ground stops its apparent upward slope? Where does that H point that marks the horizon occur? Is dependent and how far above you the object lost to the horizon is? In other words, there is no horizon point. It’s a variable. The tops of tree are lost to the “horizon” further away than the trunks are?

(http://oi68.tinypic.com/mb3lv8.jpg)
What is determining where the red line appears to stop sloping upward and the blue line is level?

Is H variable, even if I’m not changing my height over the ground?
(http://oi65.tinypic.com/2ngc64i.jpg)

The key for understanding this idea of perspective is the introduction to the section "PERSPECTIVE ON THE SEA". There he describes some observations he made.  Basically he observed that far away people seem to melt with the street. This effect is obviously the consequence of the limited optical resolution of our eyes. But for him this is the key to understand perspective. The limiting angle of optical resolution is something like 1°, but for him this is the angle of perspective lines relative to ground going away from the vanishing point.

Regarding any explanation about the vanishing point, this point is always at eye level. The consequence of this is, that point most far away to be observed is always at eye-level (anything beyond the vanishing point is to small to be visible). Within in this framework this is logical consequence, there is no other possibility. And cause the angle is fixed, the the distance to the vanishing point is not fixed. It moves away with your elevation, it comes closer if you go down.

Therefor, if you are at the sea, the point most far away is the horizon. Therefor the horizon is always at eye-level. There is no other option within this model.

Of course, all this is based on misunderstandings of optics, oversimplified drawings and so on. The biggest drawback is, that he explains everything only in a vertical plane. But perspective works in all directions, it is isotropic. Would you apply his model also to the horizontal plane, everything would look like if we would live in a tunnel. Obviously he never thought about all the consequences of his model. It is also not quite clear why the sun is visible anyway in England, because it is always further away than the horizon. OK, it is bigger and higher in the sky, but I guess that if you would put numbers into his model, you would find lots of contradictions regarding height, size and distance.

But anyway, this what comes closest to a theory in the whole book and is the most central part of all his "experiments", observations and explanations. And therefor this obsession of the flat-earth believers with this "horizon at eye-level" claim. If this fails, most of the other stuff will also fail. It's the house of cards everything is build upon. So they will never accept anything, that is in contradiction to this claim. 

 
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 16, 2018, 07:49:09 AM
See my post on page 7:

Quote from: Tom Bishop
The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

This suggested that the camera was looking up at the device and everything was not perfectly leveled.

....so 904 pixels in total, and the centre should be 452?

So the error is 33/904 in both directions, or 4%.

Do you consider that a significant error, in the context of the experiment? 
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 16, 2018, 07:56:27 AM
There is nothing wrong with your conclusion. They should all line up on a flat surface.
Right. So...you raise the first 3 up so they are at altitude - all 3 at the same altitude as each other. If your eye is at that altitude and you look across the 3 of them so they all line up then the 4th, at the horizon, will now appear below that level. Right? It can't possibly line up because it is not physically aligned. There's your horizon dip. And that would occur on a flat earth or a globe for slightly different reasons. The horizon is physically a point on the ground. The two jelly beans or water tubes or whatever are at an altitude. There is no way the two points at the same altitude and the one on the ground can form a straight line.

I agree that in Bobby's experiment the result is not clear but I think with the equipment he has made and on a clear enough day at a high enough altitude he would show a clear result.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 07:56:50 AM
....so 904 pixels in total, and the centre should be 452?

So the error is 33/904 in both directions, or 4%.

Do you consider that a significant error, in the context of the experiment?

So you want to try and manipulate with statistics now in attempt to downplay the need to align the camera?

904 pixels is a pretty low resolution photograph. Lets add some zeros to the differences seen.

4190 pixels vs 4850 pixels -- Yes, the difference is significant.

41900 pixels vs 48500 pixels -- Yes, the difference is significant

There is nothing wrong with your conclusion. They should all line up on a flat surface.
Right. So...you raise the first 3 up so they are at altitude - all 3 at the same altitude as each other. If your eye is at that altitude and you look across the 3 of them so they all line up then the 4th, at the horizon, will now appear below that level. Right? It can't possibly line up because it is not physically aligned. There's your horizon dip. And that would occur on a flat earth or a globe for slightly different reasons. The horizon is physically a point on the ground. The two jelly beans or water tubes or whatever are at an altitude. There is no way the two points at the same altitude and the one on the ground can form a straight line.

I agree that in Bobby's experiment the result is not clear but I think with the equipment he has made and on a clear enough day at a high enough altitude he would show a clear result.

Why are you rambling? We know that the horizon will dip or be in surplus if all three jelly beans are not lined up. Bobby needs to align his eye with the jelly beans for this experiment. Bobby needs to align the camera with the water level of the water device. He can't be looking down at it, or looking up at it.

When you are looking up at the water device, the straight line from your eye is now pointing in to the sky! No wonder the horizon might appear to slightly dip.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 16, 2018, 08:12:32 AM
We know that the horizon will dip or be in surplus if all three jelly beans are not lined up.
Right. And the horizon is a point on the ground.
On a round earth it is basically the edge of the globe as it curves away from you.
On a flat earth it is the furthest point you can see on the flat earth, yes?
But either way it's a point on the ground.

So if your first two jelly beans are at altitude, the same altitude as each other, and the third jelly bean is on the ground then those three beans cannot be in a straight line. If you look across the first two so they line up, the third will appear to be below the other two. That's your horizon dip. How can you possibly think that three jelly beans where two are at altitude and the other is on the ground can form a straight line?  ???
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 08:14:27 AM
How can you possibly think that three jelly beans where two are at altitude and the other is on the ground can form a straight line?  ???

This is testing the Flat Earth Theory of whether the horizon is at eye level. Read the title of this thread. Did you forget that already? Are you just arguing to argue?
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 16, 2018, 08:20:04 AM
This is testing the Flat Earth Theory of whether the horizon is at eye level.
I understand that. And so far 4 different experiments have shown that it isn't at eye level.
And your own thought experiment explains why.

Do you agree the horizon is a point on the ground?
Do you agree that "eye level" is looking straight in front of you, parallel to the ground?

If you agree those two things then if you have two jelly beans at the same altitude as one another and you look across them that is eye level.
If the 3rd jelly bean is on the ground at the horizon then those 3 jelly beans cannot possibly be in a straight line.

The experiments confirm that but it's just basic geometry.
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 16, 2018, 08:35:34 AM
The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

Are you just arguing to argue?

Again, do you consider this a significant error in the experiment? It's perfectly possible for it to be within the bounds of experimental error, and still be valid.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 16, 2018, 08:44:19 AM
If the center of the picture, which should be identical to the center of the optical system of the camera is really already below the horizon in the picture, the whole thing is useless. Don't make it so easy form them, you can do better...
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 16, 2018, 09:06:09 AM
If the center of the picture, which should be identical to the center of the optical system of the camera is really already below the horizon in the picture, the whole thing is useless. Don't make it so easy form them, you can do better...

So you would be happy if the experimenter mounted the camera on a frame attached to the cage, with an adjustment bracket, and took setup shots, counting the pixels every time, until a perfect centre was achieved?
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 16, 2018, 10:43:31 AM
If the center of the picture, which should be identical to the center of the optical system of the camera is really already below the horizon in the picture, the whole thing is useless. Don't make it so easy form them, you can do better...

So you would be happy if the experimenter mounted the camera on a frame attached to the cage, with an adjustment bracket, and took setup shots, counting the pixels every time, until a perfect centre was achieved?


Either you do the experiment as perfect as possible or you don't do it at all. As it is now, you don't even reach the point to discuss about the result, you are stuck into discussion on the realization of the experiment.

Personally I wouldn't do the experiment at all, because as I explained above, the outcome is obvious. And even if you get in the end a picture where no one can complain about the setup and the execution of the experiment, they will kill it with the simple question "how do you know that Euclidean geometry works over long distances?".

It's a useless discussion. Go and read EnaG and try to understand it. Then you will find so many obvious loopholes in the whole description that are really hard to explain.

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 01:27:56 PM
See my post on page 7:

Quote from: Tom Bishop
The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

This suggested that the camera was looking up at the device and everything was not perfectly leveled.

....so 904 pixels in total, and the centre should be 452?

So the error is 33/904 in both directions, or 4%.

Do you consider that a significant error, in the context of the experiment?

It's not error. The alignment of the water levels is immaterial to the cube. The cube is just a platform to which the water tubes are attached for stability and unity. But if ignoring the lines of perspective, and all you care about is sighting along the water levels, it doesn't matter how the cube is oriented or whether the water levels are centered on the cube.

(http://oi63.tinypic.com/34orhhs.jpg)

You don't even have to put the camera inline with the two water tubes, because you're not measuring a point. You're measuring a line. The line of the horizon. So if you extend the sight line of the level of the water laterally, you can level your eye or camera on that, as an index. You just need to get the index line right, aligned with the level of the water.

(http://oi67.tinypic.com/27xgzdx.jpg)

You could even turn the who thing 90degs to the sighting line. You just need a horizontal rule to make sure you are making a good judgement as to horizontal, but the point (again) isn't to actually measure the drop. It's just to see if it exists.

(http://oi65.tinypic.com/2en0md1.jpg)

Tom's jellybean alignment analogy isn't germane. I'm not trying to line up the water levels with a point on the horizon. I'm trying to compare the line of the water levels with the line of the horizon.

And the tilt or centeredness of the cube has nothing to do with that. The cube doesn't come into play unless assessing the perspective lines. Then, orientation of the cube because very important and you don't want it tilted forward or backwards at all. But you can still have the water level high or low on the cube. They don't have to be dead center. You just need to get the camera at the same level. And the camera needn't be dead center, laterally, either. The lines of perspective will shift along (or parallel to) the horizon as the camera moves left or right at the same level as the water.

Camera height, relative to the water level, will change everything. Tom is absolutely right about that if that's any part of his criticism. But where the camera/water is relative to the center of the cube? No. They don't all have to be lined up even. You just need to be able to know that they are at the same level. It's a lateral, horizontal line we're after. Not a point. We're not looking for curve the way the Bedford Canal experiment did it.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 01:39:01 PM
The jellybeans in Bobby's experiment are the two water surfaces in the water device and the horizon. The camera needs to line up with the two water surfaces to see if the horizon lines up with it. The pictures Bobby has shown shows that the number of pixels between the top of the picture and the water device surfaces/white string were less than the number of pixels between the bottom of the picture and the water surfaces/white string.
Maybe you should think of my sight indices as lengths of licorice sticks instead of jellybeans. The horizon is a long one laying on it's side. And the water levels are two short ones, also laying on their sides. My camera or eye can be along another length of line anywhere behind the water level licorice sticks. I'm trying to get them to line up vertically.  (And I'm not trying to line up the horizon. I'm trying to see where the horizon ends up when I get the water levels lined up in the vertical.)

Quote from: Tom Bishop
The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

This suggested that the camera was looking up at the device and everything was not perfectly leveled.
[/quote]This is wrong. If the alignment of the camera is below the level of the water, the two tubes water levels will not be aligned. The orientation of the cube or how high or low they are in the picture or in relation to the cube has nothing to do with it. Count pixels between the water levels in the front tube and the rear tube. That's where you know if the camera is looking up or looking down.

The orientation of the cube and where the water level lines up on the height of the cube only comes into play when incorporating the perspective line aspect of this demo.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 01:43:14 PM
The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

Are you just arguing to argue?

Again, do you consider this a significant error in the experiment? It's perfectly possible for it to be within the bounds of experimental error, and still be valid.
Please don't argue with him about whether or not the error is significant.
It isn't error. He's not understanding the setup. He's thinking Bedford maybe. That's not what this is.
He's looking for precision in something that is irrelevant. I specifically did not try to manage the water level and the sighting string to be dead center inside of the cube. It doesn't have to be. That would just be for aesthetics. It has no bearing on the measurement. He's misunderstanding. (At least I hope he is, because it would upset me if he's just being intentionally distracting.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 01:56:15 PM

It's a useless discussion. Go and read EnaG and try to understand it. Then you will find so many obvious loopholes in the whole description that are really hard to explain.

Maybe you're right, at least the part of adding the lines of perspective aspect. I simply do not understand what Rowbotham is talking about in those sections on perspective near the surface or at sea. He talks about perspective correctly, but then warps it in application, such that somehow lines bend. The ground plane slopes up to eye level but then stops sloping at the horizon and turns parallel. And where it does that depends on variables that are different for different things. So, where's the horizon?

Seems to me that regardless of whether the horizon for the sun is thousands of miles away while the horizon for a ship is 20 miles, they line up at eye level, right? So who cares how far away the horizon is. Is it always at eye level or not?

Who cares if my cube wires converge at different distances away from me, depending on how far away from the center of my eye they are? All I care about is if they converge on the LINE of the horizon. Which they should. Whether we're talking Euclidean or Rowbotham geometry. I don't see a disagreement. The disagreement is if that convergence is always at eye level, regardless of distance away. I don't think my approach is contrary to Rowbotham's premise. However the hell he explains things strangely in the to/from direction, it's not changing the side-to-side aspect, which is all "horizon at eye level" cares about.

It shouldn't be this confusing, but FE is trying to make it so. It's a simply proposition. "Horizon is at eye level." Is it? How does anyone know? I don't have a protractor in my neck or a clinometer in my brain. I can't tell the difference between a few degrees of tilt longways. I need to gauge it.

I think the perspective lines work and enhance the water level gauge, but if it just causes distraction, then just think of the cube as a mounting device and forget about the wires and lines of perspective.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 02:04:35 PM
From yesterday evening.
(http://oi64.tinypic.com/34t6g54.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 16, 2018, 02:10:53 PM
Regarding possible errors. You have to make sure that the distance between the aligned water levels compared to the horizon is significantly larger than the distance between the aligned water levels and the center of the picture. Than everything is fine. All other arguments regarding errors and alignment you can just ignore. It's just distraction from the real question.   
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 02:11:53 PM
What do you know? The perspective lines converge on the same plane as the water levels.
(http://oi65.tinypic.com/21brnyh.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 16, 2018, 02:32:47 PM
That looks pretty good to me!

Well done for persevering with this.

Can i ask what height you were at? And i can also make out an island to the right of the picture, what is the island, and how far away is it?

There seems to be a reasonable horizon, and i would suggest it is the actual horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 04:48:54 PM
Can i ask what height you were at? And i can also make out an island to the right of the picture, what is the island, and how far away is it?
View from Mt. Soledad in La Jolla. My vantage spot was around 790' elevation, based on topo map.

That isn't an island. It's part of the coastline looking: Oceanside to San Clemente. Maybe as far as Dana Point, but I think visual limit due to conditions was around 40-50 miles. The Coronado Islands off of Baja Mexico were visible. I could not see San Clemente Island until barely picking it out when backlit by the setting sun. And that's 60 miles away and visible on a clear day; the kind which SoCal might not get until September.

I still don't know at what point we can declare the apparent horizon "true." I can guarantee that achieving perfect surface-level visibility will not gain the kind of rise needed to bring the apparent horizon in that picture up to the eye-level line. If it could, then I'd be able to see a horizon beyond and above San Clemente on a clear day. Never have.

(Never seen the shoreline of San Clemente either. Only the tops of its hills. Maybe by September, I'll have picked up a telescope...perhaps not one as powerful as Tom used to see across Monterey Bay...and I'll try to spot San Clemente and Catalina, and see if their shorelines can be magnified into view or a horizon line above and behind them. Because if that's where the "true" horizon is, it's never been seen.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 05:24:37 PM
Quote from: Tom Bishop
Quote
The distance from the top of the picture to the string is 419 pixels and the distance from the bottom of the picture to the string is 485 pixels. This means the center of camera lens is below at the level of the water, looking up at it.

This suggested that the camera was looking up at the device and everything was not perfectly leveled.
It suggests the camera had a forward pitch.

(http://oi65.tinypic.com/2n0o9pg.jpg)

I made no effort whatsoever to level the camera's focal plane to horizontal because that doesn't affect the phenomenon which is under investigation. I adjusted pitch to best frame the picture.

But I made every effort to make sure that the camera lens was at the same level as the water.  Once done, so what if the camera has a tilt? The fact that the resulting 1600x900 resolution picture wasn't perfectly split by the water level at 450px in the vertical doesn't mean that the camera was not at the same level as the water.

I could apply roll, pitch and yaw to the camera and it wouldn't change the geometry. It would only change the framing (and some optical parameters, like focus and white balance, depending on what dominated the field of view).


Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 16, 2018, 06:23:34 PM
From yesterday evening.
(http://oi64.tinypic.com/34t6g54.jpg)
That is great work. Well done.
And this is what I was trying to explain to Tom earlier.

If 3 jelly beans are in a line on the (flat) ground and the third of those is at the horizon then if your eye is at ground level you would expect the three beans to line up.
If you raise the first two beans to an altitude and leave the third one on the ground at the horizon then they can't possibly still be in a straight line, it has to be a triangle, so if you look across the first two beans - assuming they are the same altitude as each other - then the 3rd would obviously appear below that level.

The two water filled tubes are the first two jelly beans. They must be level with each other and thus at the same altitude because water will be level and the camera must be level with that because you can see the water level lines up in the picture. The third jelly bean is at the horizon and as Tom's thought experiment predicts is below the level of the first two. Simple geometry proves that must be the case, that picture is experimental evidence of it.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 07:25:15 PM
I apologize since I'm not paying close attention to the Bedford Level and Wallace retest debate. I'm not sure if y'all are discussing the same point as the "horizon always at eye-level" claim.

But, here are some later observations from that same position. The only difference is I rotated counter-clockwise to point toward the expected azimuth of the setting sun.

Here's the oblique view, again with the camera at the height of the water but offset to the left of the cube to line up the tubes, with same results:

(https://4.bp.blogspot.com/-l1NwZJo91sM/Wvx9JhwC4AI/AAAAAAAAJko/N9O901kKVKUr29ILGTnY3wCs2whghx27wCLcBGAs/s1600/Soledad%2BSunset%2B1.jpg)

And with my perspective lines drawn in to verify "eye level" marries up with the water level line:

(https://3.bp.blogspot.com/-RLqVquZDv7M/WvyAiqIDf3I/AAAAAAAAJlc/qmdG9Dt47vQUoReLUCYmyGNsedFXeVJyACLcBGAs/s1600/Soledad%2BSunset%2B4%2Bwith%2Blines.jpg)

When I raised the camera level to get the level line to rest on the apparent horizon, the water levels in the tubes no longer align:

(https://1.bp.blogspot.com/-QVktHC8Jbms/Wvx9J1e3LvI/AAAAAAAAJkw/H7xB8SWYjcM_G0foiTRZ8xSZt9JxV2B9ACLcBGAs/s1600/Soledad%2BSunset%2B2.jpg)

Come back down a bit to get the water levels back together and the horizon is below the level line again.

(https://3.bp.blogspot.com/-AGD-mqn9h08/Wvx9Jkcbc6I/AAAAAAAAJks/PDCNNTanGVkehrrMQ4FTFjGNcNcJjeXHwCLcBGAs/s1600/Soledad%2BSunset%2B3.jpg)

Moving the camera to a frontal view through the cube, maintain level with the water:

(https://4.bp.blogspot.com/-DjgmYGS1HwM/Wvx9Kz9rNaI/AAAAAAAAJk0/BU2BEy9fCO82fs6_kb58snsDVm9J60QuACLcBGAs/s1600/Soledad%2BSunset%2B4.jpg)

Eye level confirmed with perspective lines:

(https://3.bp.blogspot.com/-sJbJVt4lXc8/WvyAifHcySI/AAAAAAAAJlY/JFYb1RdJ9KgdSGp3SHWPhUd7G6Qk14iHgCLcBGAs/s1600/Soledad%2BSunset%2B7%2Bwith%2Blines.jpg)

Sun is overexposed, making cube/water levels under exposed, but sun is affirming the horizon line, and it's not level with the eye:

(https://2.bp.blogspot.com/-2Mmyj3cP1gc/Wvx9Lki-s_I/AAAAAAAAJk4/c_nIhdZgacQl4E6UtZtu6bxp6bGSMdXpwCLcBGAs/s1600/Soledad%2BSunset%2B5.jpg)

Sun is now being eclipsed by the horizon (or whatever it is FE says is the reason for the appearance of a setting sun on the horizon):

(https://4.bp.blogspot.com/-Pd9IOsP0imY/Wvx9LzcZVqI/AAAAAAAAJk8/fCPm9JhUFvo70oNrc1LtTa2x7dPKVdFxQCLcBGAs/s1600/Soledad%2BSunset%2B6.jpg)

But if that level line (level with the water and upon which the perspective lines of the leveled cube intersect) is "eye level" it is above the horizon. Thus, the horizon cannot always at "eye level" because it's obviously not here. If the horizon IS what is level to the eye, then there's got to be something wrong, either with:
1. the water level and the cube must be pitched backward somehow, or;
2. the horizon is higher than the setting sun

There's no indication that the cube is not level. Not the plumb bob. Not the torpedo level. Even if it wasn't straight and level, how can the water level be fooled?  Even if I'm not precisely lining up the levels, the smidgen up or down that it could be in error won't bring the level line to the apparent horizon, outlined by the sun.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 07:41:01 PM
And a last check against the lines of perspective:

(https://1.bp.blogspot.com/--Fsk4k-GSkQ/WvyIj5oQtyI/AAAAAAAAJlw/9ormDuyQXuQXRHY4-8-Pr7w19AC6aB3lQCLcBGAs/s1600/Soledad%2BSunset%2B8%2Bwith%2Blines.jpg)


Oh, and there's San Clemente Island, I think, now silhouetted by the setting sun's glow, 65+ miles away. I'll have to double-check the azimuth. If it's Catalina, that's even further, but I doubt it.

(https://1.bp.blogspot.com/-Fru7EuV88m0/Wvx9MUp3D8I/AAAAAAAAJlA/wfzuV9aVolEYR0OxK1d3Tdc05ZDXrxj4gCLcBGAs/s1600/Soledad%2BSunset%2B7.jpg)

Nope. Not San Clemente Island. It *IS* Catalina.
(https://1.bp.blogspot.com/-8dE3PfKeqCg/WvyMhY3EAbI/AAAAAAAAJmE/sws5d6CiSR8rBR7w6SErcqPJz9Bu9bgqACLcBGAs/s1600/Catalina.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 09:00:03 PM
(https://1.bp.blogspot.com/-QVktHC8Jbms/Wvx9J1e3LvI/AAAAAAAAJkw/H7xB8SWYjcM_G0foiTRZ8xSZt9JxV2B9ACLcBGAs/s1600/Soledad%2BSunset%2B2.jpg)
(click to enlarge)

Take a close look at this one. We can see that this is an example that it is clearly possible for the horizon to line up with the string depending on slight positioning.

The water levels in the water device are not lined up in this image, it is asserted; but again, the camera is not aligned with the "jellybean points" in the scene. The top half to the string is 434 pixels and the bottom half to the string is 571 pixels. The camera is not exactly centered.

In most of these pictures the camera is always from below. What happens when the camera is from below and you are looking at an points above you in the foregound, even slightly? Your straight line of sight with the foreground points that recedes into the distance beyond is pointing upwards into the air! It is not pointing level.

Recall the jellybean analogy, where jellybeans at your feet stretch into the horizon. Your eye needs to be looking at the jellybeans in the exact center line of the jellybeans to see whether they line up. You can't be slightly above or below the line of jellybeans.
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 16, 2018, 09:17:05 PM
(https://1.bp.blogspot.com/-QVktHC8Jbms/Wvx9J1e3LvI/AAAAAAAAJkw/H7xB8SWYjcM_G0foiTRZ8xSZt9JxV2B9ACLcBGAs/s1600/Soledad%2BSunset%2B2.jpg)
(click to enlarge)

Take a close look at this one. We can see that this is an example that it is clearly possible for the horizon to line up with the string depending on slight positioning.

The water levels in the water device are not lined up, it is alleged; but again, the camera is not aligned with the "jellybean points" in the scene. The top half is 434 pixels and the bottom half is 571 pixels. The camera is not exactly centered.

In most of these pictures the camera is always from below. What happens when the camera is from below and you are looking at an points above you in the foregound, even slightly? Your straight line of sight with the foreground points that recedes into the distance beyond is pointing upwards into the air! It is not pointing level.

Recall the jellybean analogy. You need to be looking at the jellybeans in the same center line of the jellybeans. You can't be slightly above or below the line of jellybeans which stretch into the horizon.

So the one picure you take issue with is the one where the operator deliberately moved the camera away from being level with the water? Did you miss this, above the picture?

"When I raised the camera level to get the level line to rest on the apparent horizon, the water levels in the tubes no longer align:"
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on May 16, 2018, 09:17:40 PM
-snip-

Take a close look at this one. We can see that this is an example that it is clearly possible for the horizon to line up with the string depending on slight positioning.

The water levels in the water device are not lined up, it is alleged; but again, the camera is not aligned with the "jellybean points" in the scene. The top half is 434 pixels and the bottom half is 571 pixels. The camera is not exactly centered.

In most of these pictures the camera is always from below. What happens when the camera is from below and you are looking at an points above you in the foregound? Your line of sight with the foreground points and into the distance beyond is pointing upwards into the air! It is not pointing level.

Recall the jellybean analogy. You need to be looking at the jellybeans in the same center line of the jellybeans. You can't be slightly above or below the line of jellybeans which stretch into the horizon.
The camera was not leveled; it could have had a slight angle of attack.

BRB taking pics to prove my point
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 09:19:17 PM
(https://4.bp.blogspot.com/-Pd9IOsP0imY/Wvx9LzcZVqI/AAAAAAAAJk8/fCPm9JhUFvo70oNrc1LtTa2x7dPKVdFxQCLcBGAs/s1600/Soledad%2BSunset%2B6.jpg)
(click to enlarge)

Again, the camera is not centered. The top half of the image to the string is 524 pixels. The bottom half of the image to the string is 536 pixels.

The camera is level with the water. You're counting pixels from top to bottom, but that's not calculating level.

"Centering" as you seem to want to have it would mean making sure the camera is not only level in height with the water level but also set with focal point perpendicular to plumb. That way, a photo taken with resolution of 900px in the vertical will be perfectly split by the level line.

That's nice and all, but it's not necessary. I can point the angle downward to get more sea and less sky. Or point it up to get more sky and less sea. But that won't change the height of the camera relative to the water level, and the level line won't move up or down. The level line will move if I raise or lower the height of the camera or raise or lower the water level, or raise or lower the cube holding the water tubes.

I think I could even pitch the cube forward and backward without changing the water level line height, as long as it is pivoting on a centered axis (which it probably won't).

But this insistence that the photo show a vertically centered water line is mistaken.   
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 09:20:00 PM
(https://1.bp.blogspot.com/-QVktHC8Jbms/Wvx9J1e3LvI/AAAAAAAAJkw/H7xB8SWYjcM_G0foiTRZ8xSZt9JxV2B9ACLcBGAs/s1600/Soledad%2BSunset%2B2.jpg)
(click to enlarge)

Take a close look at this one. We can see that this is an example that it is clearly possible for the horizon to line up with the string depending on slight positioning.

The water levels in the water device are not lined up, it is alleged; but again, the camera is not aligned with the "jellybean points" in the scene. The top half is 434 pixels and the bottom half is 571 pixels. The camera is not exactly centered.

In most of these pictures the camera is always from below. What happens when the camera is from below and you are looking at an points above you in the foregound, even slightly? Your straight line of sight with the foreground points that recedes into the distance beyond is pointing upwards into the air! It is not pointing level.

Recall the jellybean analogy. You need to be looking at the jellybeans in the same center line of the jellybeans. You can't be slightly above or below the line of jellybeans which stretch into the horizon.

So the one picure you take issue with is the one where the operator deliberately moved the camera away from being level with the water? Did you miss this, above the picture?

"When I raised the camera level to get the level line to rest on the apparent horizon, the water levels in the tubes no longer align:"

This one picture shows that slight positioning can allow the string to rest on the horizon. This is not a slam dunk.

The center of the camera lens is sitting vertically from below, looking upwards at the water levels in the water device in this image. The top half of the image to the string is 434 pixels and the bottom half of the image to the string is 571 pixels. It is not centered.

In the jellybean analogy of jellybeans stretching into the horizon, your eye needs to be centered with the jellybeans to line them all up. Your eye can't be slightly above or below.

"Centering" as you seem to want to have it would mean making sure the camera is not only level in height with the water level but also set with focal point perpendicular to plumb. That way, a photo taken with resolution of 900px in the vertical will be perfectly split by the level line.

That's nice and all, but it's not necessary. I can point the angle downward to get more sea and less sky. Or point it up to get more sky and less sea. But that won't change the height of the camera relative to the water level, and the level line won't move up or down. The level line will move if I raise or lower the height of the camera or raise or lower the water level, or raise or lower the cube holding the water tubes.

I think I could even pitch the cube forward and backward without changing the water level line height, as long as it is pivoting on a centered axis (which it probably won't).

But this insistence that the photo show a vertically centered water line is mistaken.

Of course it needs to be vertically centered. The center of the lens needs to be at the same altitude of the water levels in the water device. Otherwise you are looking slightly upwards or downwards at it. A very small angle misalignment with the line of sight of bodies in the foreground creates a very large angle numerous miles away.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 16, 2018, 09:30:01 PM
Take a close look at this one. We can see that this is an example that it is clearly possible for the horizon to line up with the string depending on slight positioning.
Of course it is. The horizon is a line, the string is a line. Of course you can place the camera so those two things line up.
That's what has been done.

Quote
The water levels in the water device are not lined up, it is alleged
It's not really an allegation, you can clearly see from the image that they aren't. And that is the point. The only way to line up the string with the horizon, because the horizon is below eye level, is for the camera to be angles slightly downward. And that is why the two water levels are now different.

In the rest of the photos the two water levels are the same, that proves the camera is lined up properly and looking straight ahead. I can't work out how you figure it's pointing upwards.
The horizon is quite clearly below the level of the water, so not at eye level.

What I find interesting is that would be true on a flat earth, so why are you arguing against it?
I know you like the idea of a debating club and all, people arguing from a position they don't actually hold. Maybe that's what you're doing here.
But there has to be some spirit of honesty too and just denying clear proof like this isn't honest debate.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 09:30:16 PM
So the one picure you take issue with is the one where the operator deliberately moved the camera away from being level with the water? Did you miss this, above the picture?

"When I raised the camera level to get the level line to rest on the apparent horizon, the water levels in the tubes no longer align:"
I didn't notice he'd done this, but you are exactly right.

It's not the pitch of the camera that causes that unleveling. It's the height.

It's not "centering." There's point in trying to capture the level sighting at the precise center of the framed picture. I could exaggerate it so that level was shown near the extreme top of the image. Or at the extreme bottom. I could even tilt the camera. All that is no different from cropping a picture after having taken it. It's a framing issue. It's not influence the measurement.

It's the camera's height that's key.
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on May 16, 2018, 09:39:39 PM
BRB taking pics to prove my point
Alright Tom, let's put this jelly bean thing to rest once and for all.

I lined up a few lego figures on my table like this:

(https://s31.postimg.cc/6fx14o9rv/846_BF341-57_E3-4920-86_D6-_C9_C34_E7_B8439.jpg)

As you can see, they are in a (mostly) straight line. Thus if I align the camera on that line, they will be superimposed like so:

(https://s31.postimg.cc/tu50gl4jv/1_E5_BFA46-_F5_AB-4911-_B695-_DDA9041743_DE.jpg)

Thing is, the figure in front isn't necessarily centered. I took a second one with a lower angle of attack where it's also superimposed. I also could have cropped the one above to make the top lower.

(https://s31.postimg.cc/50vgfyo4b/A2_CA4620-44_EF-4175-_A5_E7-501_CA85066_F9.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: MCToon on May 16, 2018, 09:43:40 PM
It seems that Tom Bishop has just one remaining exception with this experiment: the camera is not vertically centered.

Tom, if the camera is vertically centered and you can count the same number of pixels above and below the line would you accept this as a valid experiment and acknowledge the results?
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 16, 2018, 09:48:53 PM
The center of the lens needs to be at the same altitude of the water levels in the water device. Otherwise you are looking slightly upwards or downwards at it.

And it IS "at the same altitude of the water levels in the water device" in all the photos, EXCEPT the one you singled out, where the operator DELIBERATELY moved it away from centred to demonstrate what 'wrong' looks like. 
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 09:55:28 PM
Of course it needs to be vertically centered. The center of the lens needs to be at the same altitude of the water levels in the water device. Otherwise you are looking slightly upwards or downwards at it. A very small angle misalignment with the line of sight of bodies in the foreground creates a very large angle numerous miles away.
No.

This seems so simple to me. I don't know how to explain it to you.

The camera has a field of view. Okay? Changing the pointing angle won't change the height or the angle between the camera lens and the water level. Height and angle remain the same. The angle of incidence of the ray from water level to the lens changes. Yes. But that won't alter the geometry. If it alters anything, it'll alter the optics, like distortion or clarity or focus, but none of that will have any bearing on what we're after here, particularly at the minute incident angles involved.

And before you start saying it does, if you were inclined, that's a separate issue from what you are saying, about changing the viewing angle or relative heights. That's a flat "no," and unless you can comprehend this basic point, I don't know how we can even have a discussion or analysis about the rest of the test.

Here's what I do. I set up the apparatus first. I spend most of my time on that, and only because I'm trying to get it square and level for the purposes of the perspective element of the demo. If I didn't care about that, I could just throw it on the mount and not worry about level. The water will level itself. But I won't be able to use the lines of perspective of the cube. The cube will no longer matter.

But because I want it to, I level the whole rig left/right, forward/backward. And it's an ordeal, especially when there is wind buffeting. I can't use the plumb bob in the wind, and the plumb bob is proven to me to be the most sensitive to departure from level. But I still use the spirit level and the bubble level on the tripod used to hold the rig.

As for the water levels in the tube? I don't care if they're filled so that they are exactly center on the cube. For convenience, I make sure they're filled so that they fall somewhere between the middle space. Because that's the range of freedom of have with my horizontal guide line. If I'm not going to bother sighting through the cube, I don't even need that. I'll just line the tubes up. But the sight line allows me to move the camera off angle from the tubes yet maintain level with the tubes.

I make sure the guide line is level by, after aligning it with the water level miniscus (love that word) on one end, measuring the height of each end to 1/64th of an inch. I also eyeball it and if it doesn't look right, I'll double and triple check until not only does every level match but my eye agrees.  I work my way around, checking it along each side of the cube.

Once that's all done, I measure out 3 feet from below the cube tripod and set up the camera tripod. I get it roughly at the same height, mount the camera, and then start finding the actual level height. I zoom in on the water level and try to match up with the guideline. I pan across the guideline. I tilt up and down. I zoom out, zoom in, fine tuning the height of the camera on the tripod. Once I feel good about the height of the camera, I lock it in. Now, the camera is level with the water, as long as I don't bump or move the tripod.

But I can still pan, tilt, zoom...and none of that will change the level height relationship.

If I have to move the camera in the tranverse, like line up with the tubes or line up so that I can shoot through the cube, I have to check level height again and adjust if necessary. But once I have it level, I can pan/tilt/zoom and it doesn't effect the level relationship.

I choose to frame the picture using pan/tilt/zoom depending on the aesthetic or the point I want to focus in on. But there's no requirement that I lock the camera in at all degrees of freedom just to try to get an image with the same amount of space above and below the level line. That's ridiculous.

If there's some ocular reason why a miniscule degree of angle of incidence to the lens centerpoint is critical for this kind of test, at this kind of focal length such that the light from the water tube alignment needs to be entering the lens and hitting the camera sensor at precisely 90°, I have no idea why that would matter. It's a false fear that any distortion from that kind of off-axis viewing through the lens would cause the level lines to be untrue.

You're not even saying that. At least not yet. You're just confusing what impact certain degrees of freedom of the camera will have on the observation. If need be, I will take images of the same setup with only the camera pitch changing. And I'll show you have the water level alignment will not change, whether I'm pointing the camera down from level or up from level. As long as I'm not changing height of the camera, all that's doing is changing the field of view.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 10:06:06 PM
It seems that Tom Bishop has just one remaining exception with this experiment: the camera is not vertically centered.

Tom, if the camera is vertically centered and you can count the same number of pixels above and below the line would you accept this as a valid experiment and acknowledge the results?
If he says yes, then I'll just crop the photos so that the view line is always in the exact center.

I'd rather he understand why the camera pitch doesn't change the level alignment. I think, maybe, he's thinking in terms of points along a line, whereas this is a planar problem. I don't know.
Title: Re: The Horizon is Always at Eye Level
Post by: MCToon on May 16, 2018, 10:13:44 PM
It seems that Tom Bishop has just one remaining exception with this experiment: the camera is not vertically centered.

Tom, if the camera is vertically centered and you can count the same number of pixels above and below the line would you accept this as a valid experiment and acknowledge the results?
If he says yes, then I'll just crop the photos so that the view line is always in the exact center.

I'd rather he understand why the camera pitch doesn't change the level alignment. I think, maybe, he's thinking in terms of points along a line, whereas this is a planar problem. I don't know.

I doubt cropping will satisfy Tom's objections.

I like your idea of angling the camera up and down while still keeping the view of water leveled, this will necessarily raise and lower the camera height.  This will resolve an concerns about how it will affect the water level and horizon relationship.  In practice rather than in theory.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 10:44:35 PM
An illustration:

(https://i.imgur.com/Hd6TTuk.png)

Most of the pictures are taken from very slightly below. No wonder the straight line path is empty space.

What is so difficult to see about this?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 10:45:00 PM
Here are two pics from the other day. Both are 1600x900.

This one (http://oi63.tinypic.com/34p05s0.jpg) does not have the water level line centered vertically within the frame.

This one (http://oi67.tinypic.com/2f03qbs.jpg) is "centered" with the water level line splitting the frame.

They were taken sequentially. The only difference was zoom. I didn't even change the camera pitch.

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 10:48:04 PM
An illustration:

(https://i.imgur.com/Hd6TTuk.png)

Most of the pictures are taken from very slightly below. No wonder the straight line path is empty space.

What is so difficult to see about this?
That's not the correct conclusion to draw from your method of photo analysis. Counting pixels from the top and bottom of the photos to find a centerline does not tell you whether or not the camera was level with another object. It only tells you how the object was framed.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 10:50:44 PM
Here are two pics from the other day. Both are 1600x900.

This one (http://oi63.tinypic.com/34p05s0.jpg) does not have the water level line centered vertically within the frame.

This one (http://oi67.tinypic.com/2f03qbs.jpg) is "centered" with the water level line splitting the frame.

They were taken sequentially. The only difference was zoom. I didn't even change the camera pitch.

First your argument is that "no altitude leveling is required! Why should I need to do that?" and also expressed arguments of the difficulty in doing that. You also then threaten to crop some photos.

Then your next post is of a picture you took in the past where it is centered exactly.

How convenient.

That's not the correct conclusion to draw from your method of photo analysis. Counting pixels from the top and bottom of the photos to find a centerline does not tell you whether or not the camera was level with another object. It only tells you how the object was framed.

I have been assuming that your camera is leveled exactly horizontally here. If the camera were fixed in a horizontal position the pixels need to match up in frame to ensure that the center of the lens was in line with the objects. You are right. I have been assuming that the camera was exactly horizontal. I was wrong to assume too much. If you are just tilting the camera willy nilly, there could be several issues with the leveling, enough that a pixel count is insufficient.

How am I supposed to know how much you are tilting your camera at and the altitude of the center of the lens?

Regardless, the illustration I have provided shows that this is a very sensitive experiment.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 11:09:29 PM
First your argument is that "no altitude leveling is required! Why should I need to do that?" …
You've attributed something to me in quotes. Where did I say this?

I think I communicated that altitude leveling IS required. Both the water levels and the camera MUST be level. No looking up at the water levels. No looking down at the water levels. They must be level.

What's not required if having the camera oriented perpendicular to that plane. I can tilt it down. But that's not looking down at the water levels. The camera is still at the same height. I can tilt up, but that's not looking up at the water levels. The camera is still at the same height as the water levels.

(http://oi67.tinypic.com/16k9s21.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 16, 2018, 11:11:21 PM
It is simply not necessary to take the pitch of the camera into account, as long as the picture taken includes the relevant parts, ie the horizon (and those pictures show a reasonable horizon for sure.)

Let’s use Toms current favourite, the Bishop Jellybeans If you line up the jellybeans, and look at floor level along them, they will all line up, and superimpose. Or are in Transit. That is his statement and i guess he will need to stick to that.

Now without moving your head (camera) from the plane of the jellybeans, (the floor) and glance up at a point a few degrees above the far jellybean. Do they come out of alignment? Of course not. Now do the same, moving your eyes only, (camera lens)  glance down slightly at as point a few degrees below the jellybeans. Are they still in alignment or transit? Of course they are.

All, you have done is tilt the camera lens (eye) on the axis of the plane, and altered the angle of the lens slightly, allowing you to focus slightly above or below the jellybeans. They are still in alignment or transit, they have not moved, and niether has what you see (apart from more of what is above or below the jellybeans)

There is no way in that experiment to get the water in the nearest tube to align with the water in the furthest tube AND align with the horizon, as the horizon is on a different plane.

You can always get the level of 2 elements to align, but never the 3.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 11:15:29 PM
…and also expressed arguments of the difficulty in doing that.
Tom.  You crisscross things I say all the time.

What I expressed difficulty in doing was getting the CUBE setup LEVEL.  And that was ONLY for the usage of its LINES OF PERSPECTIVE.

Somehow, you've taken that and conflated it with matching the level of the CAMERA with the level of the WATER in the TUBES.

Getting the cube level is hard, but it's immaterial to the water level measurement.
Getting the camera at the same height as the water level needs to be careful, but it's not hard.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 11:18:51 PM
(http://oi67.tinypic.com/16k9s21.jpg)

Sure. I can agree with that. I have been assuming that your camera was horizontal. In that case, if you are just tilting it at your pleasure, then the number of pixels doesn't really mean much.

Clearly, this is a very sensitive experiment. Clearly, there is some question on whether the camera is exactly leveled. I moved the camera down by one pixel in my last illustration and it created a huge gap in the background.

If not pixels, since you are tilting the camera willy nilly, how can we know where things are positioned?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 11:19:04 PM
You also then threaten to crop some photos.

Then your next post is of a picture you took in the past where it is centered exactly.

A. I didn't crop the photo
B. Even if I did, it wouldn't matter.

I can "crop" the photo by aiming the camera or crop it in edit. The amount of space above and below vertical centerline is not an indicator of camera height.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 11:26:08 PM
I have been assuming that your camera is leveled exactly horizontally here. If the camera were fixed in a horizontal position the pixels need to match up in frame to ensure that the center of the lens was in line with the objects. You are right. I have been assuming that the camera was exactly horizontal. I was wrong to assume too much. If you are just tilting the camera willy nilly, there could be several issues with the leveling, enough that a pixel count is insufficient.

How am I supposed to know how much you are tilting your camera at and the altitude of the center of the lens?

Regardless, the illustration I have provided shows that this is a very sensitive experiment.
No, you haven't.

Why does the camera have to be horizontal for this experiment? Why do you need to know the tilt (pitch)?

You don't. It's a planar problem. Is the camera lens in the same plane as that of the water level? And does that match the plane of the horizon.

I don't have to have the camera horizontal in all planes, vertical through horizontal. Just the horizontal. (Not even the horizontal. I'm typing too furious. It's the camera's elevation that's of critical importance.) I can pitch, roll and yaw the camera, but as long as the height of the camera is at the same elevation as the water level and that plane is in the field of view, we've got a good setup.

Seeing the two water tubes' water level line up is the indicator the camera is at the same level plane. Counting pixels is above/below vertical centerline is nonsense.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 11:31:40 PM
(http://oi67.tinypic.com/16k9s21.jpg)

Sure. I can agree with that. I have been assuming that your camera was horizontal. In that case, if you are just tilting it at your pleasure, then the number of pixels doesn't really mean much. 

Bobby: Precisely.

Clearly, this is a very sensitive experiment. Clearly, there is some question on whether the camera is exactly leveled. I moved the camera down by one pixel in my last illustration and it created a huge gap in the background.

Bobby: Wait! What?

If not pixels, since you are tilting the camera willy nilly, how can we know where things are positioned?

Look at the water level. That's what it's there for.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 11:34:54 PM
Look at the water level. That's what it's there for.

And how do we know whether the camera is not very slightly above or below the water level?
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on May 16, 2018, 11:37:50 PM
I moved the camera down by one pixel in my last illustration and it created a huge gap in the background.
Strictly speaking, pixels only measure angles. And tilting the camera down wouldn't affect the alignment of the water columns in the image.

You're gonna run out of excuses eventually. This activity by Bobby has conclusively proved that the world is round.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 16, 2018, 11:40:16 PM
I moved the camera down by one pixel in my last illustration and it created a huge gap in the background.
Strictly speaking, pixels only measure angles. And tilting the camera down wouldn't affect the alignment of the water columns in the image.

You're gonna run out of excuses eventually. This activity by Bobby has conclusively proved that the world is round.

Bobby has already posted a picture showing that slight modifications to the altitudes makes the horizon appear in line with the string that goes through the middle. This is a sensitive experiment. The slight altitudes and alignment in the foreground all matter very much. We need to see something that shows we can trust those altitudes and the alignment.

If we can't trust a pixel method, because bobby is tilting the camera willy nilly, how do we know whether the level is of the camera is the same at the water device?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 16, 2018, 11:56:50 PM
Look at the water level. That's what it's there for.

And how do we know whether the camera is not very slightly above or below the water level?
If the water levels in the tubes line up, the camera can't be anywhere else.

How "slightly?" Do you want me to work out a camera height delta from a setback of 36" from the water tubes within which I can't really tell if they're aligned or not?

I mean, I will. And I can then also calculate AND demonstrate the impact that would have on the sighting against a horizon line.

I'm more than will to work that out and show you. I thought I did that with my photos, but I didn't record just how much I had to raise/lower the camera to make that happen. But if that's critical to you, I welcome that input.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 12:00:43 AM
This activity by Bobby has conclusively proved that the world is round.
Appreciate this, but if it's proved anything yet (which I think we're still in the preliminary stage, working out kinks and challenges), it's that the horizon is not always at eye level. Whether or not that kills flat earth, I don't know.

On the other hand, if the horizon was actually always rising to eye level, there's no way the earth surface could be convex. But since we're not seeing that, convexity survives. How flatness could explain a falling horizon with rise in elevation is another story.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 12:00:55 AM
I moved the camera down by one pixel in my last illustration and it created a huge gap in the background.
Strictly speaking, pixels only measure angles. And tilting the camera down wouldn't affect the alignment of the water columns in the image.

You're gonna run out of excuses eventually. This activity by Bobby has conclusively proved that the world is round.

Bobby has already posted a picture showing that slight modifications to the altitudes makes the horizon appear in line with the string that goes through the middle. This is a sensitive experiment. The slight altitudes and alignment in the foreground all matter very much. We need to see something that shows we can trust those altitudes and the alignment.

If we can't trust a pixel method, because bobby is tilting the camera willy nilly, how do we know whether the level is of the camera is the same at the water device?

I thought the tilting business was explained and accepted by you? So it is not relevant.

Or a dont you understand still about the tilt, pan and the difference between that and changing the plane (altitude) of the camera? And are trying to confuse the issue by mixing the plane of the camera (altitude) and tilt of the camera?
Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on May 17, 2018, 12:01:50 AM
Bobby has already posted a picture showing that slight modifications to the altitudes makes the horizon appear in line with the string that goes through the middle. This is a sensitive experiment. The slight altitudes and alignment in the foreground all matter very much. We need to see something that shows we can trust those altitudes and the alignment.
And the point was that it misaligns the columns.
Quote
If we can't trust a pixel method, because bobby is tilting the camera willy nilly, how do we know whether the level is of the camera is the same at the water device?
Gee, it's almost like there are TWO water columns for that exact purpose!
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 17, 2018, 12:21:00 AM
If the water levels in the tubes line up, the camera can't be anywhere else.

Gee, it's almost like there are TWO water columns for that exact purpose!

These water columns are only a few inches away from each other. It may as well just be big single glass of water. The closer we get things to our face in the foreground, the more accurate all leveling needs to be. You are assuming that we can just wing it on the imprecise nature water tension and the fact that the water levels are arguably off very slightly in the images.

None can doubt that a slight error in altitude and leveling in the foreground can create a large impact on the background. You are just winging without knowing how precise you need to be.

The horizon is one of the the furthest thing on earth that can be measured. Don't you think that maybe the requirements with such slight leveling and alignment in the foreground are pretty important?
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 12:33:17 AM
If the water levels in the tubes line up, the camera can't be anywhere else.

Gee, it's almost like there are TWO water columns for that exact purpose!

The horizon is one of the the furthest thing on earth that can be measured. Don't you think that maybe the requirements with such slight leveling and alignment in the foreground are pretty important?

And yet i dont see you suggesting that any of the experiments in EnaG that use plumb bobs and protractors, or levels are in error? You seem to accept all of them as gospel, experiment 15 does, as do many of his other experiments, and that experiment measures the horizon (apparently)
If it is so vital for the experiments to be perfectly level, then why did Rowbotham not detail his method of levelling, the hieght of his experiments, or show exactly what he did to level his “clinometer” he even put the word “levelled” in brackets. I would suggest to show he might have had doubts???

Surely the same level of standards should be applied to Bobbys experiment, as at least he is willing to show how he got his answers, and discuss it, much more than EnaG does.

Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 17, 2018, 12:35:52 AM
And yet i dont see you suggesting that any of the experiments in EnaG that use plumb bobs and protractors, or levels are in error? You seem to accept all of them as gospel, experiment 15 does, as do many of his other experiments, and that experiment measures the horizon (apparently)
If it is so vital for the experiments to be perfectly level, then why did Rowbotham not detail his method of levelling, the hieght of his experiments, or show exactly what he did to level his “clinometer” he even put the word “levelled” in brackets. I would suggest to show he might have had doubts???

Surely the same level of standards should be applied to Bobbys experiment, as at least he is willing to show how he got his answers, and discuss it, much more than EnaG does.

Rowbotham specifically avoids debates about the accuracy of his surveying methods by designing experiments that have two modes: success or fail. Is the object in the distance visible, or is it hidden by the curve of the earth? Simple experiments.

We cannot really take him to task on his surveying methods for that purpose.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 12:48:46 AM
And yet i dont see you suggesting that any of the experiments in EnaG that use plumb bobs and protractors, or levels are in error? You seem to accept all of them as gospel, experiment 15 does, as do many of his other experiments, and that experiment measures the horizon (apparently)
If it is so vital for the experiments to be perfectly level, then why did Rowbotham not detail his method of levelling, the hieght of his experiments, or show exactly what he did to level his “clinometer” he even put the word “levelled” in brackets. I would suggest to show he might have had doubts???

Surely the same level of standards should be applied to Bobbys experiment, as at least he is willing to show how he got his answers, and discuss it, much more than EnaG does.

Rowbotham specifically avoids debates about the accuracy of his surveying methods by designing experiments that have two modes: success or fail. Is the object in the distance visible, or is it hidden by the curve of the earth? Simple experiments.

We cannot really take him to task on his surveying methods for that purpose.

And his experiment 15?

He looks out of a window with a “clinometer” then runs up a flight of stairs with same object, and measures the horizon, and determines that there is no difference? The whole outcome of this experiment is acutely dependant on his instrument being levelled. And yet we cannot dispute the accuracy of it?

His measurements of the sun from London’s bridge and Brighton are equally false, and have been shown to be vastly inaccurate, but these figures are used to calculate distances of the sun from the earth.

A lot of his experiments are dependant on a level or measurement, and there is not a single explanation on how he does this, experiments 3,4,6,11,14,15, plus many in the later chapters fail if the levelling was not done correctly, or his measurements not accurate. He also relies upon the accounts of writings in newspaper articles as evidence.
I fail to see how all of his experiments are not required to be accurate!
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 17, 2018, 01:33:31 AM
And yet i dont see you suggesting that any of the experiments in EnaG that use plumb bobs and protractors, or levels are in error? You seem to accept all of them as gospel, experiment 15 does, as do many of his other experiments, and that experiment measures the horizon (apparently)
If it is so vital for the experiments to be perfectly level, then why did Rowbotham not detail his method of levelling, the hieght of his experiments, or show exactly what he did to level his “clinometer” he even put the word “levelled” in brackets. I would suggest to show he might have had doubts???

Surely the same level of standards should be applied to Bobbys experiment, as at least he is willing to show how he got his answers, and discuss it, much more than EnaG does.

Rowbotham specifically avoids debates about the accuracy of his surveying methods by designing experiments that have two modes: success or fail. Is the object in the distance visible, or is it hidden by the curve of the earth? Simple experiments.

We cannot really take him to task on his surveying methods for that purpose.

And his experiment 15?

He looks out of a window with a “clinometer” then runs up a flight of stairs with same object, and measures the horizon, and determines that there is no difference? The whole outcome of this experiment is acutely dependant on his instrument being levelled. And yet we cannot dispute the accuracy of it?

Nothing is stopping you from attacking his ability to level a clinometer. The foundational experiments of Earth Not a Globe are the basic water convexity experiments that simply assess whether bodies are visible or not, however.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 01:50:37 AM

Rowbotham specifically avoids debates about the accuracy of his surveying methods by designing experiments that have two modes: success or fail. Is the object in the distance visible, or is it hidden by the curve of the earth? Simple experiments.

We cannot really take him to task on his surveying methods for that purpose.
And yet...you are challenging the precision of my method.

It's a pass/fail test. Is the horizon level with the eye or not regardless of elevation? It's what Rowbotham did in Experiment 15. He reported it did. The premise that it does is the basis for several of his other experiments.

Rowbotham simply reported that he saw no declination in horizon from eye level. I'm showing you images, and you've questioned the legitimacy of my images. I don't mind. I welcome the questions, but I also expect a reasoned dialogue about those questions. You've not questioned Rowbotham at all and taken him at his word. Would you do that for me?

I've taken preliminary looks from elevations well higher than the top floor of the Brighton Grand.
I've shown and explained what tools I'm using to detect any dip in horizon from below eye-level. I don't know anything about Rowbotham's tool: what it was, how he leveled it, how he sighted along it's edge. If my method has potential for error margin (which I'm sure it does), then why isn't Rowbotham subject to the same level of skepticism or at least caution in accepting his conclusion carte blanche.

He makes a claim in the book that the sun appears to increase in size as it tends towards sunset. That's contrary to what others in the FE camp say, showing alleged video still evidence of a shrinking sun.  Yet, I've found no such shrink or swelling in the angular diameter of the sun. Rowbotham did nothing other than assert his claim, as if it was self-evident. I've posted pictures of the sun throughout the day, filtered for glare, using a constant focal length and then using the same technique you have for measuring angular dimension in a photo image: pixels. 

Rowbotham isn't an angel, right? Nor a saint? He can be wrong, can't he? His word is not infallible.

I'm not even asking for the same latitude you grant Rowbotham. All I want is good criticism that isn't just gainsaying or unwillingness to see how the critique is answerable. And that whatever zetetic examination you give me, do the same for EnaG. Don't just take Rowbotham's word for his results. Go out and do them yourself. Show us how it's done instead of directing us to the book or saying that Rowbotham already did it, so it doesn't have to be redone. Let's bring his experiments into the modern age. Document his results through replication. Let's get it on the FE favorite medium of YouTube.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 02:03:12 AM
These water columns are only a few inches away from each other. It may as well just be big single glass of water.
How did RS's clinometer work that makes it more trustworthy to you.

The recommendation was given early in this topic to skip the connect tubes and just use a basin. Fill it to the brim and make your sighting along that. Would that be good? Lets say a shallow receptacle of about 5 inches wide but 36 inches long.

Or, we can ditch the cube since few seem to get why that adds anything to the effort. And just use water tubes at the end of a garden hose. We can stretch that out over many feet (though I don't want to be hauling around that much water). That's the technique many use for finding level points over broad distances, like building a deck. It works. It's just cumbersome and becomes harder to get a good focus on both water levels from a single vantage point. (For leveling, you typically have two people making marks where the water level is.

Come to think of it, that's how to use the hose technique. You plant 2 vertical posts however far apart you want. Then use the hose water level to mark equivalent elevations, attach a cross member of some kind, and then do your eye-level sighting between those two sights. That actually might be the best way to do it if I wind up feeling I need to hike up one of the taller local "mountain" that don't offer me vehicle access. I could even leave it set up and, as long as county officials don't take it down, anyone could use it to inspect the horizon vs. eye-level.

Hmm. 

Anyway, I do acknowledge the issue that a short distance between the 2 level sighting lines increases the margin of error for gauging against another line much, much further away. It's geometric, and you can calculate it. But rather than do that, I'll experiment and show you the range of viewing heights does to the observation, and you can decide if it matters. I have an idea how to do that, so check back in the next couple of days and I'll have something for you.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 02:15:00 AM
The horizon is one of the the furthest thing on earth that can be measured. Don't you think that maybe the requirements with such slight leveling and alignment in the foreground are pretty important?
Since you mentioned it, how far away IS the horizon? I can't get a handle on what the horizon even is in EnaG.

Seems maybe it's not a single point, but a continuous plane that runs parallel to the eye, and distance along that plane is dependent on how high (or low) other planes are from eye level. If you put jellybeans on the floor and lay down so your eye is level with the jellybeans, how far away is the jellybean horizon? If the sun is on a plane 3000 miles over the earth, how far away is the sun horizon? You know, that variable point where the ground plane stops sloping up and turns horizontal to eye-level:

(http://www.sacred-texts.com/earth/za/img/fig97.jpg)

Frustrates me that this leaves me baffled.

I can calculate a distance to the horizon on a globe earth within some degree of confidence, knowing height of the observer and fudging for refraction. But I have no idea if there's a way to know the distance to the horizon on a flat earth or how it can be the furthest thing on earth that can be measured.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 17, 2018, 01:58:49 PM
This activity by Bobby has conclusively proved that the world is round.
Appreciate this, but if it's proved anything yet (which I think we're still in the preliminary stage, working out kinks and challenges), it's that the horizon is not always at eye level. Whether or not that kills flat earth, I don't know.

On the other hand, if the horizon was actually always rising to eye level, there's no way the earth surface could be convex. But since we're not seeing that, convexity survives. How flatness could explain a falling horizon with rise in elevation is another story.
I don't think you have proved a round earth directly, but you have certainly proved horizon dip, despite Tom's desperate flailing.
Note how Tom mentioned none of the objections he is now raising when shown the initial experiments.
I can't tell if he's just being stubborn or in "debate club" mode and enjoying trying to keep a debate going when you have killed it stone dead and settled the matter pretty conclusively.

To prove a globe - or provide good evidence for it - you would need to calculate the angle of horizon dip expected on a globe at different altitudes and then show experimentally that the dip angle is as expected. That would give confidence in the model.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 02:54:03 PM
In trying to demonstrate for Tom how much the camera height needs to change for figuring a margin of error on "eye level," I realize I may be able to do that.

In the meantime, here are 3 stills from the same shot, with the only change being camera height. The top image is camera lower than water level, producing a sighting in which the near tube level appears 1px higher than the far tube level. I can see the misalignment with my eye.

In the middle image, I eyeballed the water to be level, but measuring from the bottom of the meniscus in each tube, the level of the near tube is actually 1px lower than the far tube level. That means the camera is higher than the water level.

In the bottom image, the camera is definitely too high since I can clearly (IMO) see that the near tube water level is lower than the far tube's.

The tubes are about 14" apart and the guideline is equidistant between them.
The camera is set back about 30" from the near tube.
These are un-resized stills from a video clip, and I can't remember what resolution my camera is set to record video in, so I can't yet work out the geometry to see what angular dimension 1px of image is equivalent to. But working that out, I should be able to calculate how much the camera was moved in the vertical axis to generate the differences in the top and bottom images.

The top and bottom images are what I would consider the boundaries for margin of error, and my guess is the camera height was adjusted by about 1" between 1px too low (top image) to 1px too high (middle image).  The third image is 5px too high, and yet the guide string still hasn't reached the apparent horizon, so even with this margin of error, from about 800' in elevation, it doesn't seem to matter in answering a yes/no question of whether or not the horizon is at eye level. Even giving "eye-level the benefit of doubt at the outer range of error margin, there's still a gap.

(http://oi65.tinypic.com/20pq1hu.jpg)

I hope to reproduce this and actually take measurements of the change in camera height rather than deduce it through calculation, but in the meantime, have a look at the video clip:
https://www.youtube.com/watch?v=6O_7qaSB1_Y
Knowing the dimensions of the water leveler/camera setup up, and gauging the amount of camera height adjustment needed to bring the guideline in contact with horizon, we can, in fact, calculate the "dip" from level horizon. What will be missing is a target at a known distance that would be on the tangent point of the assumed globe.

I didn't notice it at the time, but there is a container ship that becomes apparent on the horizon just north of the setting sun. It might be possible to use that if we assume not too much of it's hull is obscured by the horizon (or convergence zone if you prefer) and we can estimate it's size/class.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 03:08:45 PM
(http://oi67.tinypic.com/okuds0.jpg)

Maybe 800-1000ft long.
35-40ft above the waterline.

Looks like we're seeing it from close to 90degs, (probably heading out from Long Beach). Given how much of it we're seeing, I might very well be close to the distance where a globe earth would predict the visual horizon to be. Might be a fun exercise in geometry/trig to see.

(However far away it is, I'd say it's clearly below "eye level" so a FE model might need to start on a rework of the explanation for the apparent horizon, I would say.)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 03:18:22 PM
(http://oi67.tinypic.com/okuds0.jpg)

Maybe 800-1000ft long.
35-40ft above the waterline.

Looks like we're seeing it from close to 90degs, (probably heading out from Long Beach). Given how much of it we're seeing, I might very well be close to the distance where a globe earth would predict the visual horizon to be. Might be a fun exercise in geometry/trig to see.

(However far away it is, I'd say it's clearly below "eye level" so a FE model might need to start on a rework of the explanation for the apparent horizon, I would say.)

The horizon form 800 feet up using GE tables gives you a 33.1 nautical mile distance, or 38.1 statute mile distance.

The ship slightly below the horizon is a supertanker, in the region of 330M long, and from waterline to deck will vary between 10m when loaded to about 20M when empty. I think she is half hull over the horizon, or half loaded or a combination of the 2. I also recon you have a pretty good clear horizon there.

I know this because i have worked in those waters, on those ships, and was a captain of the smaller ships that load out there, and have worked in the area where they do ship to ship cargo transfers, which are in that region, and pretty much where you are taking the shots.

Try looking on “marine traffic.com” and see if you can identify it, i realise it might have left, but if it is doing a cargo operation it will hang around for 24 hours or so. If you have a signal on the point where you take the observations you might get lucky and find the name of the ship next time, and from that you can find the course (giving aspect) and length so might be able to use that. If nothing else you might get the distance away it is.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 03:33:45 PM
Just looked on Marine traffic, and i recon the ship is the “sea passion” 333M long, and she is likely to have been in the area for about 36 hours.

I know this because i can see from your picture she is a large crude carrier, and believe me there are NOT that many inn that part of the world. As i said I have worked on that operation and in that area.

Her AIS data shows she is fully loaded and would have a about 15 metres of hull above the waterline. She will also have instructions to remain a minimum of 25 miles off the coast at the headlands, so it is safe to say she is at least that distance away.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 03:46:28 PM
This is all too lucky. Now, we do have a target and might be able to calculate a dip below eye level and see if it matches that predicted by spherical earth.

I did rough CAD estimate and figure the length to height (not superstructure) is about 1:21. If you're right about the ship, then we can deduce how much of the hull should be above the water line and, then, how much (if any) is obscured by horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 03:55:16 PM
Another gauge might be the sun itself. At the horizon, it is filtered enough by the marine layer that you can see it's truer size, and at 32 arcminutes, the sun would give us a ruler of sorts to use for the ship.

(http://oi65.tinypic.com/esrr4k.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 04:07:36 PM
The sun would be a much better measure, as it will give you the dip in arc minutes, and i can tell you what that is supposed to be.

The semi diameter of the sun will be 15.8 arc minutes, or 31.6 across the diameter. You can get this info from nautical tables.

I would not use the vertical measurement as the refraction affects this, however horizontal measurement is pretty good.

The fact that you measured it at 32 arc minutes is verified as pretty close, as the semi diameter is published and known.

Title: Re: The Horizon is Always at Eye Level
Post by: MCToon on May 17, 2018, 04:26:30 PM
Bobby, you have performed a pass/fail experiment as EnaG claims to do:

Pass: Horizon is visibly on the same plane as the water in the tubes
Fail: Horizon is visibly not on the same plane as the water in the tubes

I've read experiment #15.  In this thread you have provided more documentation and rigor than shown in the book.  Tom is simply refusing to accept the results.  He doesn't seem to want to answer my question about vertically centering the image.  I'll ask again:
"Tom, if the camera is vertically centered and you can count the same number of pixels above and below the line would you accept this as a valid experiment and acknowledge the results?"

If your answer is "no", then what are your requirements to perform this experiment?  What equipment did you use when you verified the horizon rises to eye level claims in EnaG?


Title: Re: The Horizon is Always at Eye Level
Post by: 9 out of 10 doctors agree on May 17, 2018, 04:32:05 PM
Just looked on Marine traffic, and i recon the ship is the “sea passion” 333M long, and she is likely to have been in the area for about 36 hours.

I know this because i can see from your picture she is a large crude carrier, and believe me there are NOT that many in that part of the world. As i said I have worked on that operation and in that area.

Her AIS data shows she is fully loaded and would have a about 15 metres of hull above the waterline. She will also have instructions to remain a minimum of 25 miles off the coast at the headlands, so it is safe to say she is at least that distance away.
What is her mast height? Bobby seems to be measuring it from that.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on May 17, 2018, 04:37:12 PM
Here are six simple ways for measuring whether the horizon is at eye level or not:

1. Use a professional theodolite. Eye level is where the crosshair is:

(https://www.metabunk.org/attachments/screenshot-178-png.29725/)

2. Download and properly calibrate a theodolite app. Eye level is where the crosshair is:

(https://www.metabunk.org/data/MetaMirrorCache/2280a2eb67935d369dbdac8a06ed4097.jpg)

3. Make your own theodolite using a spirit level. Eye level is level with the top of the spirit level, when you're sighting along it:

(https://www.metabunk.org/attachments/diy-theodolite-jpg.26429/)

www.metabunk.org/posts/204999

4. Use parallel lines to find the vanishing point (which is always at eye level):

(https://www.metabunk.org/attachments/wtc-lines-jpg.28259/)

5. Take a picture of some actual eyes, with the camera at eye height, and see where the horizon is:

(https://www.metabunk.org/attachments/wtc1-jpg.27470/)

6. Use a homemade water level. Eye level is where the surfaces of the water are aligned:

(https://www.metabunk.org/attachments/horizon-level-liquid-test-jpg.27615/)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 04:39:33 PM
This is an annotated 1920x1080 resolution image taken as sunset
on 5/15/2017 at 19:41 PDT
from La Jolla's Mt Soledad
32.840319
-117.245065
approx. 790' MSL
on an azimuth of ~294° true
(http://oi66.tinypic.com/35l4w8m.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 04:43:12 PM
Here are six simple ways for measuring whether the horizon is at eye level or not:
May not be simple, but don't forget Tontogary's measurement from horizon to horizon using a sextant and finding >180° from an elevated position.

And it's gratifying to see the level lines of perspective being used as well. I hadn't seen that before, but it backs up what I was attempting with my caged cube thing.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 04:49:31 PM
I feel like, maybe, this is all become accelerated with the Mt. Soledad sighting. I was just practicing, not thinking I was going to have a clear enough horizon, but it worked out better than I anticipated.

I'd still like to collect careful sightings and data from different elevations and without the haze (though the sun at sunset pretty clearly cuts through it to make the horizon undoubtable). And also address Tom's skepticism about the setup by showing the impact of changing certain parameters, like camera height, pitch, yaw, and doing the same for the cube.  All just so that it is clear by demonstrate what can and can't affect the measurement.

But it's becoming clear that the horizon being always at eye level is not likely true.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on May 17, 2018, 04:56:59 PM
[And] don't forget Tontogary's measurement from horizon to horizon using a sextant and finding >180° from an elevated position.

Thanks for that: I wasn't aware anyone had done it.

Has he posted photos/videos anywhere? I shall add it to my list. :-)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 05:24:08 PM
I'm pretty sure it's back in the early pages of this topic. Anecdotal account, but he provided details on his instrument in response to Tom.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 05:48:21 PM
I have to share this.

Stopping by Mt. Soledad on Tuesday was a lark. I work in an area of San Diego called Point Loma, and my commute home takes me to north county inland on I-15. But on driving out from Point Loma, I could tell the horizon was sharp enough and that maybe I'd be able to get some good sighting against it. So, on the spur of the moment, I decided to give Soledad a try. It's been years since I'd been to the overlook that sits atop La Jolla. 800"+ with coastal views from Baja to Orange County.

I got there about an hour and half before sunset and there were very few people there. I found a spot on the lawn, near the edge of a drop, that gave me a clear view to the WNW, because I did hope to capture a sunset with the leveling rig. It was gusty at times, but I set up the cube/water level first. Inevitably, I had people saunter by to ask me what I was doing.

I have to confess, I'm shy about admitting what I'm doing is to check on a flat earth/globe earth debate issue. I'm about as certain we live on a globe earth than just about anything else in life, so it's a valid question why I am even bothering with all this. It's not like I want to rock anyone's beliefs. But I guess not wanting to admit I've dived into this reveals a level of embarrassment that I am. I love the passion that flat earth people have, and I think I'm just fascinated by what drives that passion. Plus, I do enjoy a good debate/discussion, and who knows? Even if I think I know things, I can learn more by challenging what I think I know and examining why I think I know it. I feel like I've learned a lot. Not to persuade me to change my mind, but to affirm what I thought I already knew to greater degree of certainty.

Anyway, I concocted a specious story that I was just an amateur photography and wanted to capture the setting sun through a wired cube to create a demonstration of perspective lines that I would add to the photos in post. Sort of an art project, and maybe a demo for art students. Not sure if it was convincing, but I couldn't admit I was doing a project to prove/disprove a flat earth claim.

The crowd started to grow as sunset approached, and as expected, people asked what I was doing. I actually had very nice conversations with several people, and one woman spent much time talking to me while we waited for sunset.

Afterward, when the sun was gone and it was turning twilight, a young man with a bike idled over and, like others, asked what this was all about. I gave him my story, and added the fact that I wanted to show how the lines of perspective converged on the horizon. Well, he apparently was already familiar with the concept and mentioned the flat earth, saying that he had looked into it (videos, mainly) and felt there was much to make you wonder.

Yikes. I wanted so badly to fess up and admit that this was precisely to investigate a flat earth/globe earth disagreement. Instead, I acted like I was unaware of the controversy and told him that in my line of work, the fact that the earth is a sphere is a given and a flat earth couldn't be hidden. I was dismissive of the flat earth notion, but there I was, secretly doing a flat earth experiment.

I wondered if maybe he might browse by this forum and recognize these photos, maybe from the green water and Soledad location. If you are here, dude; I'm sorry I didn't come out of the closet with you. It would have been great to have a face-to-face conversation with even a flat earth agnostic. I've never met anyone in person who was (or at least would admit it.) I think I came across as being totally dismissive of the flat earth notion, like such a thing wouldn't be worth my time. But that was for my own ego.

I think from now on, when people ask, I'm just going to be honest and explain the concept and why I'm doing it. I figure eventually I'll put it all together in a Web page, in case anyone wants to reference the results. I don't think I'll make a video, though that seems to be the favorite way to communicate both globe and flat earth arguments.

Not sure if that's interesting or "on topic," but thought I'd mention it. You just can't set something like this up in public and not expect to draw attention.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 17, 2018, 05:55:59 PM
Bobby, you are asking us to place a lot of faith in the properties and surface tension of the fluid you concocted.

Recall that slight positioning places the horizon in line with the string. It appears possible to get the horizon lined up with the string in a range entirely within the surface tension area:

(https://1.bp.blogspot.com/-QVktHC8Jbms/Wvx9J1e3LvI/AAAAAAAAJkw/H7xB8SWYjcM_G0foiTRZ8xSZt9JxV2B9ACLcBGAs/s1600/Soledad%2BSunset%2B2.jpg)
(click to enlarge)

Take a close look at this one. We can see that this is an example that it is clearly possible for the horizon to line up with the string depending on slight positioning.

Here is a researcher who states that the water level cannot be directly measured because of surface tension effects:

From Encyclopedia Britannica (https://books.google.com/books?id=LCRKAQAAMAAJ&lpg=PA264&ots=WUcn-_iBIK&dq=capillary%20action%20%22is%20not%20level%22&pg=PA264#v=onepage&q=capillary%20action%20%22is%20not%20level%22&f=false):

(https://i.imgur.com/CdMWbMd.png)

Look at the illustration in the above image. The surface tension is not always universally uniform, and the level of the surface tension can change within the same immediate container.

We are assuming the material of the tube's effects upon whatever kind of dyed liquid that is. We are assuming uniform shape of the surface tension. We are assuming a lot of things. Other types of liquids even display a more convex, rather than concave, effect.

The researcher above states that there is so much uncertainty that the level cannot be directly measured.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 06:16:22 PM
You may have missed it, but I raised the issue of the interaction of the fluid with the plastic tubing a few days ago. Learned a new word ("meniscus") and a new term ("wetting angle").

Sighting along the edge of the fluid levels was a concern for me, and I volunteered it. The vinyl tubing is kind of thick. Forget the inner diameter dimension, but there's probably a 1/4" of vinyl to see through. It's not as ideally transparent as I'd like. Plus, I didn't like how the water seems to "creep" up the side of the tube, creating a convexity. I came to learn that that's dependent on the property of the liquid and the material of the container. I'd like to try adding some Rain-X to get the "wetting angle" closer to 90 degrees. In the meantime, I created a mixture of 50% water and 50% alchohol (it's vodka, actually) and I think it improves it a little.

The advice for dealing with a meniscus that's either concave or convex from 90 degs is to measure at the bottom of the thick layer. Importance isn't the actual spot, but being consistent between the two index points.

But though I'd love to have a sharp edge on the level, the uncertainty doesn't create an error large enough to make a pass/fail determination impossible. If I'm trying to measure an actual distance between the levels of the front tube and back tube to calculate an angle, then yeah. It would be a problem. And at elevations close to sea level, pass/fail might be ambiguous. But I'm seeing that once at 100' or above, even if I adjust in favor of trying to keep the horizon at the eyesight level, the meniscus is not "in the way."

It's a good critique. I'm not done trying to minimize it by finding a good combination of fluid+receptacle. Or maybe switching to an "infinity pool" concept and removing the barrier altogether. But I'm leaning toward arguing that it's below the threshold for a margin of error that could create doubt when at elevations greater than what that ambiguity can create. 

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 07:20:45 PM
Maybe we could talk about this in the Q&A section rather than here, but I would like to understand how the horizon is identified and calculated according to Earth Not a Globe principles. You've mentioned previously about need to see a "true horizon" and yesterday said something to the effect that the horizon is the furthest things on earth that can be measured.

But I've read EnaG sections dealing with the horizon several times, and I'm just not picking up on how to a true horizon is distinguished or how to measure its distance. My understanding at the moment, as flawed as it might be, is that Rowbotham figures the horizon is a function of the thing it is being sighted: it's size, it's level on a plane above (or below) the observer. Plus, I assume it's phenomenological, meaning it is an "apparent" horizon and not a physical eclipsing of sight, though air density and obscurants play a part in scattering and diffusing light so that there is an eclipsing of image.

If you respond here, fine. But if you think it better to not weave it into this topic, I'll start a Q&A one, since I'm not seeking to debate. Just apprehend the principle and it's application in an FE model.
Title: Re: The Horizon is Always at Eye Level
Post by: MCToon on May 17, 2018, 08:23:20 PM
Bobby, you have performed a pass/fail experiment as EnaG claims to do:

Pass: Horizon is visibly on the same plane as the water in the tubes
Fail: Horizon is visibly not on the same plane as the water in the tubes

I've read experiment #15.  In this thread you have provided more documentation and rigor than shown in the book.  Tom is simply refusing to accept the results.  He doesn't seem to want to answer my question about vertically centering the image.  I'll ask again:
"Tom, if the camera is vertically centered and you can count the same number of pixels above and below the line would you accept this as a valid experiment and acknowledge the results?"

If your answer is "no", then what are your requirements to perform this experiment?  What equipment did you use when you verified the horizon rises to eye level claims in EnaG?

Tom, if someone were to get a proper Transit Level and perform this experiment would you accept the results?  These are not that difficult to obtain.

For example, in Minneapolis where I live, I found one on Craigslist for $49:
https://minneapolis.craigslist.org/ank/tld/d/vintage-david-white-meridian/6570521087.html
Not too useful so far from the ocean.

Craigslist and ebay have many:
https://www.ebay.com/itm/DAVID-WHITE-Realist-Meridian-L6-20n-Transit-Level-Case/142795135576?epid=1805532287&hash=item213f40da58:g:FKwAAOSwiHZa-iBl

Some appear to have vertical angle measurement, some only can sight level.  Either way, perfect for a pass/fail test.

So, Tom, would this satisfy?


Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 10:38:01 PM
This is an annotated 1920x1080 resolution image taken as sunset
on 5/15/2017 at 19:41 PDT
from La Jolla's Mt Soledad
32.840319
-117.245065
approx. 790' MSL
on an azimuth of ~294° true
(http://oi66.tinypic.com/35l4w8m.jpg)

That pic is great!

The calculation for the amount of dip predicted with normal refraction is,
Dip = 1.78 multiplied by the square root of the hieght in Metres.

This calculates to be a dip of 27.6 minutes of arc.

You have an object of known measurement of arc, i.e. the sun, at 31.6 minutes, so can compare that with the dip you experience. It looks about right.
Also the distance to Catalina island is pretty far, and would suggest it is over the calculated RE horizon of 33.1 NM,

All of this additional evidence was not known before you took the picture i guess, and the additional information corroborates and backs up already believed science.

This is a great picture, and demo, and i applaud your efforts and the time to do the experiments.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 17, 2018, 10:45:29 PM
[And] don't forget Tontogary's measurement from horizon to horizon using a sextant and finding >180° from an elevated position.

Thanks for that: I wasn't aware anyone had done it.

Has he posted photos/videos anywhere? I shall add it to my list. :-)

I started a new thread about it a few weeks ago.

“Horizon rising to eye level and a foolproof way to measure it.” I am not sure how to link another thread, so apologise for that.

Unfortunately using a sextant to measure the altitude of a body is rather boring, and rather unphotoigenic.

\looking through the eyepiece, you cannot get a good picture, and although i could take a shot of me taking the altitude, and then showing the reading on the instrument it does not translate to video well. Pictures similarly. I dont know of a sextant that can record video or stills, as they are essentially a measuring device, where you bring the suns image to the horizon, and measure the angle.

I did however provide the calibration certificate of the sextant, along with he model number etc.

A little more scientific than EnaG, but not in the same league as Bobbys experiment here!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 17, 2018, 11:53:12 PM
These water columns are only a few inches away from each other. It may as well just be big single glass of water. The closer we get things to our face in the foreground, the more accurate all leveling needs to be. You are assuming that we can just wing it on the imprecise nature water tension and the fact that the water levels are arguably off very slightly in the images.

None can doubt that a slight error in altitude and leveling in the foreground can create a large impact on the background. You are just winging without knowing how precise you need to be.

The horizon is one of the the furthest thing on earth that can be measured. Don't you think that maybe the requirements with such slight leveling and alignment in the foreground are pretty important?
I wonder if we can qualify or quantify how much margin for error there is in each of these setup/measurement parameters just to see if we can calculate whether or not the tolerances are too great to determine, on a pass/fail basis, if horizon is or isn't at eye level.

Some of the variables for which Tom has raised precision challenges:
A) Error in matching camera/eye height to water level
B) Error in gauging water level due to meniscus
C) (more?)

We've resolved your objection about camera orientation, is that correct, Tom?
I'd still like to know how true horizon can be identified or how to calculate how far away the horizon is according to EnaG principles, but I leave that to you.

Here's a closeup of the pic in which I intentionally skewed the sighting. I've obscured the water levels by the width of the meniscus and the horizon by the width of the guideline.
There is no question that the camera height and the two water level indices are not aligned in the vertical, correct? There are clear gaps between the horizontal lines for each index marker, which means this alignment can be assessed without fear of precision error.

(https://4.bp.blogspot.com/-5wvD2ocgBQI/Wv4VvskCeuI/AAAAAAAAJmU/4ihlbkgH3xIaYrrIjp84M69dCX6QRmP3gCLcBGAs/s1600/Margin%2Bof%2BError.jpg)

The front tube water level is higher than the horizon line, which is higher than the rear tube water level. Why is this out of alignment? If the only adjustment is the camera/eye height, how does it need to be adjusted? Does the camera height need to be increased or decreased? Up? Or down?

 

Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 18, 2018, 05:34:58 AM
Bobby, lets hold on that for a moment. What are these stopper cap looking things at the top of the water device?

(https://i.imgur.com/OJARnRG.png)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 05:47:20 AM
Those are Schedule 40 PVC reducer bushings that fit snugly in the top of the vinyl tubing. They have a threaded 3/4" opening that I screw equivalent PVC plugs into for transport and remove for use. The plugs are removed in all of the test photos and videos. The bushings themselves stay in and do not restrict airflow.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 18, 2018, 06:23:47 AM
Thank you. I suppose we will have to trust you when you say that you took them out.

Per your above assertion that all of the error is contained within the black area's surface tension, what makes you think that all possible error would just be in that black area? The surface tension could also be risen higher or sunk below the true water level, as it is in this vase:

(https://i.imgur.com/0bdzHXY.jpg)

(https://i.imgur.com/poczgks.png)

The surface tension is at different levels different in the tubes of this single device. The whole claim that water is level in such devices is looking shakier and shakier.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 18, 2018, 06:30:21 AM
Thank you. I suppose we will have to trust you when you say that you took them out.

Per your above assertion that all of the error is contained within the black areas surface tension, what makes you think that all possible error would just be in that black area? The surface tension could also be risen higher or sunk below the true water level, as it is in this vase:

(https://i.imgur.com/0bdzHXY.jpg)

(https://i.imgur.com/poczgks.png)

THe surface tension is different in the different tubes of this single device. This whole "water is level in this device" claim is looking shakier and shakier.

So you are saying water is not always level??? I thought that was a fundamentals truth??

The line you have drawn is pretty inaccurate. Raise the right hand end up, drop the left hand down a bit, and a straight line will cut across all 4 surfaces. The narrower the cross section of tube, the bigger the meniscus, so more errors are introduced on the smaller tubes.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 18, 2018, 06:51:18 AM
Surface tension isn't the most predictable thing. The Encyclopedia Britannica researcher said that we shouldn't even bother trying to gauge the level of the water.

Why are we assuming that the water would be level in such an device anyway?

We are also assuming that this is all pure H20, and that there are no other fluids or substances floating on top of it:

(https://i.imgur.com/iMkuzOJ.png)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 06:51:43 AM
Thank you. I suppose we will have to trust you when you say that you took them out.
Thank you for your trust. I only ask for as much or as little as you grant Samuel Rowbotham.

Here's what the caps look like in and out. And the first photo of the day from Mt. Soledad.

(http://oi68.tinypic.com/m93mz8.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 18, 2018, 06:59:03 AM
The surface tension is at different levels different in the tubes of this single device. The whole claim that water is level in such devices is looking shakier and shakier.
But clearly in that experiment the tubes have different concentrations of...whatever that green stuff is, which affects the result.
In Bobby's experiment the tubes are connected, the concentration will be the same because of natural mixing so that won't be an issue.

I'm interested. Are you people serious about a FE model which matches observations, and taking observations yourself?
Bobby is doing a lot of work here and all you are doing is trying with increasing desperation to find problems with it.
Why don't you just take some observations yourself? You're an empiricist, aren't you?
And if your observations do match the 4 different ways you have been shown that prove that the horizon dips then you have to change your model.
That is how progress is made. You don't make progress by stating something as fact and then dismissing any experiment which shows that "fact" to be wrong.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 18, 2018, 07:01:36 AM
Surface tension isn't the most predictable thing. The Encyclopedia Britannica researcher said that we shouldn't even bother trying to gauge the level of the water.

Why are we assuming that the water would be level in such an device anyway?

We are also assuming that this is all pure H20, and that there are no other fluids or substances floating on top of it:

(https://i.imgur.com/iMkuzOJ.png)

Bobby has clearly stated that his fluid is homogeneous, (water and vodka mix) and you can see from the dye that the colour is pretty much uniform.

Your diagram shows different levels of liquid on top of a water manifold, are you suggesting Bobby has manipulated the experiment to show the water levels differently?

Are you being deliberately obtuse?

If we apply the same level of nit picking and skepticism to EnaG, not a single one of his observations stand up to any scrutiny at all!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 07:09:56 AM
Per your above assertion that all of the error is contained within the black area's surface tension, what makes you think that all possible error would just be in that black area? The surface tension could also be risen higher or sunk below the true water level, as it is in this vase:
On the contrary, that tubes are used to demonstrate how the fluid level is independent of the shape.
However, the one furthest on the left has a wider opening and so it's meniscus will be different from the other narrower openings.
Also, you've again interpreted the picture as if it is framed perfectly level. Your line is perpendicular to the picture, but if you are comparing levels, you draw a line through the levels of the fluid. So it will appear angled because the picture is skewed.
(http://oi64.tinypic.com/2jfdq47.jpg)
Nevertheless, that photo provides a good example of why the two sighting tubes should be of the same type (material, diameter, etc.) with same meniscus properties. The object is not to know the precise level but to match levels precisely (as possible).
The surface tension is at different levels different in the tubes of this single device. The whole claim that water is level in such devices is looking shakier and shakier.
I don't mind the critique, but do so knowledgeably. Please. Don't misapply or confuse information you look up just to seek a refutation of a result you aren't comfortable with.

Some things need to be accepted as foundations. If you're going to doubt the accuracy of water leveling, I"m not going to try to educate you or convince you.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 18, 2018, 07:10:39 AM
/qBut clearly in that experiment the tubes have different concentrations of...whatever that green stuff is, which affects the result.

Here is another device with more equally mixed dye:

(https://i.imgur.com/9c1K58I.png)

The same sort of imprecision is seen:

(https://i.imgur.com/duJaQms.png)
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 18, 2018, 07:16:26 AM
If we apply the same level of nit picking and skepticism to EnaG, not a single one of his observations stand up to any scrutiny at all!
This. And this is where I question whether Tom is serious about FE research or a FE model which matches observations.

Any experiment described in ENaG or which seems to confirm a result in ENaG is accepted unquestionably.
Any experiment which shows that result to be wrong is either declared fake or analysed and analysed until any tiny speck of doubt can be found and it is dismissed.
It's a pretty dishonest way of working.

Tom produced a video of a drone which he claims showed the horizon staying the same as it rose. It didn't, you can clearly see the horizon dropping as the drone rises. When I pointed that out he just said that the video isn't stabilised...well, it's no good for proving the result then, is it?
Then he produced a video showing a camera on one building looking across another building which claimed that the horizon hadn't dipped. The problems with that were
1) The horizon actually was a couple of pixels below the roof of the other building
2) The buildings were 7 stories high and near the coast, so not high enough to clearly show the result
3) There was absolutely no way of calibrating or telling that the camera was the same height as the other building.

I know Tom likes the idea of a debating club and the idea of people arguing from a position they don't hold, I suspect that is what he is doing here.
And of course for a debate you need to have two people who take contrary positions.
But where it gets dishonest is if one side is clearly shown to be wrong just refusing to accept that or concede any ground.
Then it just becomes frustrating and pointless.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 07:17:06 AM
The Encyclopedia Britannica researcher said that we shouldn't even bother trying to gauge the level of the water.
Similar to how you misquoted me earlier, you've misrepresented and misinterpreted a reference to suit a bias.
You're not being honest.  Not with me. Not with yourself. 

I'm trying to engage you in a worthy discussion.

Also, I answer your queries you direct toward me. You skip over those I direct toward you while seeking new and varied reasons to reject evidence that doesn't fit your preconceptions.

I would like you to go back and look at the picture I posted of the misaligned water levels and answer my question. It's important.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 18, 2018, 07:17:52 AM
/qBut clearly in that experiment the tubes have different concentrations of...whatever that green stuff is, which affects the result.

Here is another device with more equally mixed dye:

(https://i.imgur.com/9c1K58I.png)

The same sort of imprecision is seen:

(https://i.imgur.com/duJaQms.png)
For goodness sake, Tom!
In those you can clearly see the tubes are different shapes so they've produced the result in a different way.
That doesn't apply to Bobby's apparatus either. Why are you being so dishonest?
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 18, 2018, 07:21:08 AM
Surface tension isn't the most predictable thing. The Encyclopedia Britannica researcher said that we shouldn't even bother trying to gauge the level of the water.

Why are we assuming that the water would be level in such an device anyway?

We are also assuming that this is all pure H20, and that there are no other fluids or substances floating on top of it:

(https://i.imgur.com/iMkuzOJ.png)

Bobby has clearly stated that his fluid is homogeneous, (water and vodka mix) and you can see from the dye that the colour is pretty much uniform.

Your diagram shows different levels of liquid on top of a water manifold, are you suggesting Bobby has manipulated the experiment to show the water levels differently?

Are you being deliberately obtuse?

If we apply the same level of nit picking and skepticism to EnaG, not a single one of his observations stand up to any scrutiny at all!

Vodka floats on water.

http://www.smarterthanthat.com/experiments/a-party-trick-for-the-watery-dense/

Quote
Dense materials sink, and less-dense materials float. Water is denser than alcohol, so the alcohol floats on top of the water. Dense materials sink, and less-dense materials float. Water is denser than alcohol, so the alcohol floats on top of the water.

How do we know that it is a perfect water-vodka mix and that there is no separation?

The dye? Do any elements in that float?

Any other possible impurities?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 07:26:08 AM
The same sort of imprecision is seen:

(https://i.imgur.com/duJaQms.png)
Try it again, but instead of drawing a straight line relative to the picture orientation (same mistake you made expecting my photos to be centered), see if you can draw a straight line through the levels, being consistent as to where you cross the meniscus.

You should be able to. I can. That's level. Not the way the picture is framed. That's the point of the water leveling.

If you think a picture is always framed level, anyone can fabricate that and convince you you're seeing level. The point of the water is that you can trust it. You don't have to trust the picture-taker.

Go ahead. Retry drawing that line, but ignore the orientation/framing of the picture.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 07:32:28 AM
Vodka floats on water.
That's the kind of input I can appreciate.
I didn't know that. I added the alcohol to see if it would minimize the meniscus. But maybe it didn't. Maybe it separated and it's floating to the top of one vertical tube but not the other, and maybe the density difference is throwing off the measurement.

I can calibrate it if you think so. I plugged the tubes when done and I haven't stirred up the fluid since the experiment. If I show you the fluid levels are unaffected by the water/alcohol mixture, will you be satisfied? It is a good point, and something I hadn't considered.
Title: Re: The Horizon is Always at Eye Level
Post by: inquisitive on May 18, 2018, 07:43:07 AM

Surface tension isn't the most predictable thing. The Encyclopedia Britannica researcher said that we shouldn't even bother trying to gauge the level of the water.

Why are we assuming that the water would be level in such an device anyway?

We are also assuming that this is all pure H20, and that there are no other fluids or substances floating on top of it:

(https://i.imgur.com/iMkuzOJ.png)
Nice try, but not relevant, as you know.  Where are the results of your experiments?
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 18, 2018, 07:50:30 AM
Vodka floats on water.
That's the kind of input I can appreciate.
I didn't know that. I added the alcohol to see if it would minimize the meniscus. But maybe it didn't. Maybe it separated and it's floating to the top of one vertical tube but not the other, and maybe the density difference is throwing off the measurement.

I can calibrate it if you think so. I plugged the tubes when done and I haven't stirred up the fluid since the experiment. If I show you the fluid levels are unaffected by the water/alcohol mixture, will you be satisfied? It is a good point, and something I hadn't considered.

Either you take pure alcohol, a soap solution or just a tiny drop of oil on top of each water column. All this has a lower surface tension and therefor a less pronounced meniscus.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 18, 2018, 07:59:57 AM
The same sort of imprecision is seen:

(https://i.imgur.com/duJaQms.png)
Try it again, but instead of drawing a straight line relative to the picture orientation (same mistake you made expecting my photos to be centered), see if you can draw a straight line through the levels, being consistent as to where you cross the meniscus.

You should be able to. I can. That's level. Not the way the picture is framed. That's the point of the water leveling.

If you think a picture is always framed level, anyone can fabricate that and convince you you're seeing level. The point of the water is that you can trust it. You don't have to trust the picture-taker.

Go ahead. Retry drawing that line, but ignore the orientation/framing of the picture.

The capillary pressure is a function of the diameter of the tubes. Therefor in communicating tubes of different diameter the water level is different. But it is only the diameter at the water level which is relevant, not the shape and therefor not the overall volume of the tubes. But you have to be a bit careful how you fill the tubes to observe the real equilibrium state.

 
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 18, 2018, 08:00:31 AM

Yes you are correct, Alcohol will float on top of water. But to do so needs carefully pouring on top of the water, and to avoid stirring or mixing.

Vodka is not pure alchol, it is already diluted to about 40% with water, so is already in suspension. Mixing of any kind will keep the alcohol in suspension.

https://www.solubilityofthings.com/water/alcohols

Vodka is soluble with water, and will not “settle out” nice try tom, but clutching at straws i am afraid!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 08:20:41 AM

Yes you are correct, Alcohol will float on top of water. But to do so needs carefully pouring on top of the water, and to avoid stirring or mixing.

Vodka is not pure alchol, it is already diluted to about 40% with water, so is already in suspension. Mixing of any kind will keep the alcohol in suspension.

https://www.solubilityofthings.com/water/alcohols

Vodka is soluble with water, and will not “settle out” nice try tom, but clutching at straws i am afraid!
Checking -

1. Frame leveled vs spirit level straight edge
(http://oi65.tinypic.com/vrtwr4.jpg)

2. Tilt frame check
(http://oi63.tinypic.com/wr05ja.jpg)

3. Tilt frame from other side
(http://oi67.tinypic.com/ohtv6r.jpg)

4. Longitudinal check
(http://oi64.tinypic.com/2qnuqt1.jpg)

Looks good enough to me. I don't think fluid composition is an issue. 
Title: Re: The Horizon is Always at Eye Level
Post by: Tumeni on May 18, 2018, 08:21:19 AM
Thank you. I suppose we will have to trust you when you say that you took them out (the bushings).

OK, this is getting frackin' ludicrous now.

You. are. grasping. at. straws. by implying that the experimenter has left the tubes sealed in order to  ..... what? Align the water levels to fit his own evil agenda?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 08:28:49 AM
I don't want this to get lost.


These water columns are only a few inches away from each other. It may as well just be big single glass of water. The closer we get things to our face in the foreground, the more accurate all leveling needs to be. You are assuming that we can just wing it on the imprecise nature water tension and the fact that the water levels are arguably off very slightly in the images.

None can doubt that a slight error in altitude and leveling in the foreground can create a large impact on the background. You are just winging without knowing how precise you need to be.

The horizon is one of the the furthest thing on earth that can be measured. Don't you think that maybe the requirements with such slight leveling and alignment in the foreground are pretty important?
I wonder if we can qualify or quantify how much margin for error there is in each of these setup/measurement parameters just to see if we can calculate whether or not the tolerances are too great to determine, on a pass/fail basis, if horizon is or isn't at eye level.

Some of the variables for which Tom has raised precision challenges:
A) Error in matching camera/eye height to water level
B) Error in gauging water level due to meniscus
C) (more?)

We've resolved your objection about camera orientation, is that correct, Tom?
I'd still like to know how true horizon can be identified or how to calculate how far away the horizon is according to EnaG principles, but I leave that to you.

Here's a closeup of the pic in which I intentionally skewed the sighting. I've obscured the water levels by the width of the meniscus and the horizon by the width of the guideline.
There is no question that the camera height and the two water level indices are not aligned in the vertical, correct? There are clear gaps between the horizontal lines for each index marker, which means this alignment can be assessed without fear of precision error.

(https://4.bp.blogspot.com/-5wvD2ocgBQI/Wv4VvskCeuI/AAAAAAAAJmU/4ihlbkgH3xIaYrrIjp84M69dCX6QRmP3gCLcBGAs/s1600/Margin%2Bof%2BError.jpg)

The front tube water level is higher than the horizon line, which is higher than the rear tube water level. Why is this out of alignment? If the only adjustment is the camera/eye height, how does it need to be adjusted? Does the camera height need to be increased or decreased? Up? Or down?

Hint:
https://www.youtube.com/watch?v=6O_7qaSB1_Y
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 18, 2018, 08:50:53 AM

Yes you are correct, Alcohol will float on top of water. But to do so needs carefully pouring on top of the water, and to avoid stirring or mixing.

Vodka is not pure alchol, it is already diluted to about 40% with water, so is already in suspension. Mixing of any kind will keep the alcohol in suspension.

https://www.solubilityofthings.com/water/alcohols

Vodka is soluble with water, and will not “settle out” nice try tom, but clutching at straws i am afraid!

I would take something like ethanol or isopropanol. Should not be too expansive.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on May 18, 2018, 12:30:31 PM
At the end of the day, the water level is accurate enough for the purpose required.

If anyone disputes that, let them either show it with proper documentation, or give their protestations a rest, and maybe take a good honest look at themselves in the mirror.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 18, 2018, 12:57:01 PM
In the real world yes, but they decided to play their game and doing some experiments to present them here, so they have to play along their lines...   
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 01:22:34 PM

Yes you are correct, Alcohol will float on top of water. But to do so needs carefully pouring on top of the water, and to avoid stirring or mixing.

Vodka is not pure alchol, it is already diluted to about 40% with water, so is already in suspension. Mixing of any kind will keep the alcohol in suspension.

https://www.solubilityofthings.com/water/alcohols

Vodka is soluble with water, and will not “settle out” nice try tom, but clutching at straws i am afraid!

I would take something like ethanol or isopropanol. Should not be too expansive.
I'm not even sure the alcohol is doing what I wanted it to, which was improve the wetting angle for less ambiguous sighting of water levels. I was just trying different things: windex, water with a little dish soap, hydrogen pyroxide, isopropyl alcohol, water/antifreeze...whatever I could think of that I had at the house. Settled on the vodka (now, I'm not sure if it wasn't Bacardi's rum and not vodka. Yeah, it was rum now that I think about it. I emptied what was left of 2 bottles and mixed it with distilled water. I don't think I ever got around to trying the vodka once the rum seemed to work okay.)

But I do want to try the Rain-x. I just don't have any, and I'm loathe to buy things for this project. I like spending time on this because it's fun and you never know what you might learn; but I'm not so concerned with the flat/globe debate that I need to spend any money on it.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 03:54:59 PM
The same sort of imprecision is seen:

(https://i.imgur.com/duJaQms.png)
Try it again, but instead of drawing a straight line relative to the picture orientation (same mistake you made expecting my photos to be centered), see if you can draw a straight line through the levels, being consistent as to where you cross the meniscus.

You should be able to. I can. That's level. Not the way the picture is framed. That's the point of the water leveling.

If you think a picture is always framed level, anyone can fabricate that and convince you you're seeing level. The point of the water is that you can trust it. You don't have to trust the picture-taker.

Go ahead. Retry drawing that line, but ignore the orientation/framing of the picture.
Not going to try?

I'll help. Draw a line through the little circles. I drew them at what I think are consistent points on the miniscus of the 3 smaller-diameter vessel openings. The 4th, wider opening one, is different. The wetting angle seems closer to 90° on that one than the concavity of the others, but I gave it a shot.

(http://oi67.tinypic.com/2rf7ukk.jpg)

Do the 4 circles line up in a straight line? Can you connect the dots?

You're red line surely won't because you've drawn it parallel to the y-axis of the picture. But the orientation of the picture has no bearing on what was level in the subject. The water is supposed to orient you to that. So try it. You might be surprised.
Title: Re: The Horizon is Always at Eye Level
Post by: hexagon on May 18, 2018, 04:15:09 PM

Yes you are correct, Alcohol will float on top of water. But to do so needs carefully pouring on top of the water, and to avoid stirring or mixing.

Vodka is not pure alchol, it is already diluted to about 40% with water, so is already in suspension. Mixing of any kind will keep the alcohol in suspension.

https://www.solubilityofthings.com/water/alcohols

Vodka is soluble with water, and will not “settle out” nice try tom, but clutching at straws i am afraid!

I would take something like ethanol or isopropanol. Should not be too expansive.
I'm not even sure the alcohol is doing what I wanted it to, which was improve the wetting angle for less ambiguous sighting of water levels. I was just trying different things: windex, water with a little dish soap, hydrogen pyroxide, isopropyl alcohol, water/antifreeze...whatever I could think of that I had at the house. Settled on the vodka (now, I'm not sure if it wasn't Bacardi's rum and not vodka. Yeah, it was rum now that I think about it. I emptied what was left of 2 bottles and mixed it with distilled water. I don't think I ever got around to trying the vodka once the rum seemed to work okay.)

But I do want to try the Rain-x. I just don't have any, and I'm loathe to buy things for this project. I like spending time on this because it's fun and you never know what you might learn; but I'm not so concerned with the flat/globe debate that I need to spend any money on it.

The height of the meniscus is a function of the relative surface tension of the different interfaces involved. Water has relatively high surface tension, the different alcohols ( I mean in the chemical sense, not brands ;-) )  a much lower one, therefor less pronounced meniscus. Liquid helium would be the best. Maybe I should give it a try...
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 04:39:05 PM
I was going to post a few pictures of intentionally tilted and skewed pictures of the water leveler and have Tom show me level.

But in doing so, I discovered something odd.

(http://oi65.tinypic.com/24o8xlx.jpg)

Why is that left (usually forward-facing) water not level? Yes, it's small but it's noticeable. I'm gauging square by the door panels in the background. They should give me a parallel line to the level line of the water tubes. But even when I level the apparatus all out and correct for any skewing angle, that one on the left side seems a tad higher.

I checked for any trapped air in the PVC elbows.

I didn't have this last night when I "calibrated".  Or maybe I did? Looking back with a more critical eye at those pictures comparing water level against a spirit level, maybe there IS a slight difference with the "forward" one showing a slightly higher level than the other?

(I did just check to make sure the door in the background was square and plumb. It is.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 04:53:29 PM
Later, I'll flip the tubes in the horizontal to see if the apparent discrepancy stays with the same tube or it stays with the orientation. (It better stay somewhere. If it disappears that'll be frustrating.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 18, 2018, 11:36:33 PM
No reactions to this potential error? It's cause? Is it real? If so, how significant?

Check my math.

I measure the delta in water level as 0.09" higher in forward tube than in rear tube. What's the impact of that?

If "true" level is .045" lower in front and 0.45" higher in rear, and the tubes are 14" apart, that's a 0.18˚ error in the sighting line. For camera set back 29" (36"-7") from the rear tube, that angle error results in camera being about a tenth of an inch too low.

Intuitively, I can see that being a problem for horizon checking at low elevations where the margin is tight. But I don't think 1/10th of camera height adjustment is enough to save "horizon at eyelevel" for elevations of 800+ feet.

Is my math right? I hope to experiment and demonstrate effects on horizon/level observations with fractional camera/eye height adjustments to see how much error matters for different elevations in determing "pass/fail" of horizon rising to eye level question.
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on May 19, 2018, 12:36:46 AM
I do appreciate your honesty in your detection of this. This experiment, and others like it, are not easy or straight forward things like everyone believes. Surveying is difficult. Random public YouTubers can't just go off and perform experiments like in those videos. Surveying texts often assert that surveying is difficult, calibration of tools is difficult, and that perfect surveying is all but impossible.

The water being unlevel when tested is a major concern. It means that this is possible:

(https://i.imgur.com/Hd6TTuk.png)

Per your math, and ways to salvage it, I cannot really help you on that topic. Since we can't trust the water level, we can't really trust that we can calculate away what the error even is. We are assuming that surface tension should naturally become "level" in such a device, and not cause the true water line to be squished below or expanded upwards above the true level. And since we can only compare with another uncertain surface tension area, we don't know how much height is affected.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 19, 2018, 01:07:37 AM
I think that's close-minded, and it's a one-way philosophy. I see you very open to "maybe" and "might" and "could" possibilities that support flat earth, but dismissive and rejecting of the "could/maybe/might" when it's supportive of convexity. I can't change that, if that's your preference. You're really the only engaged flat earth proponent I've had the opportunity to interact with, so I welcome the interaction. But if we can't be on the same sheet of music, epistemological, then dialogue is hopeless.

My point of view is that I'm not approaching this from the standpoint of ultimate precision. I think you don't need to be a scientist or have access to high-tech, finely calibrated equipment to determine what is "eye level" and whether or not the horizon coincides with it. If that were true, and the ability to determine eye level or "true horizon" was so delicate and arcane, then who came up with the premise in the first place and how? I don't know anyone who can judge 90° from vertical with his/her eyes, certainly not to with resolutions of a fraction of a degree. If someone came up with the claim, how did he do it? How can any of us double, triple check and verify its truth?

As I've said several times, this isn't something we have to measure to a gnat's whisker. It's a yes/no question. Pass/fail. As such there must be thresholds at which the parameters of the tools, their orientation and their readings are within some tolerance to allow us to determine "true" or "not true" and not have to rely on someone else's authority that it is or isn't. Right? That's how I understand zetetic. I appreciate the challenges, but it seems like all you choose to do is detract and find obstacles rather than identify issues and suggest ways to improve, or determine just how much issues matter. You act like this is hopeless, and that we should be satisfied that St. Rowbotham figured it out for us and we should just accept its truth.

I can't do that. I don't have any stake in the outcome because I know with my own level of confidence that the earth IS a globe. This isn't a globe-buster or flat earth debunker issue for me. Maybe it is for you? I enjoy the process of working things out. Trying things. Finding flaws and working to refine the process to bypass or minimize the flaws. It's like a puzzle that just happens to be trying to resolve a question that's of key importance in the globe/flat earth contest. I like the puzzle. I like how it introduces me to new areas of discovery, such as the interaction between fluids and materials. Never had any cause to look into that before.

I'm going to continue this (as long as my wife doesn't mind and I don't shirk the other domestic projects I've got on my plate). I think I'm comfortable with the fact that you cannot be convinced, which was never my objective anyway. Again, I do appreciate the skepticism. If you choose to keep at it, that'd be great. But I'll use it as food for thought rather than a starting point of debate. I hope you understand.

(I'll ask you -- or anyone, really -- to help me understand the FE horizon and its calculation on the QA board. Not to debate. I just want to apprehend it.)
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 19, 2018, 07:49:47 AM
I do appreciate your honesty in your detection of this. This experiment, and others like it, are not easy or straight forward things like everyone believes. Surveying is difficult. Random public YouTubers can't just go off and perform experiments like in those videos.
Fine, and that's probably true. But when random YouTubers make a video which backs up something you believe you accept it unquestioningly.
Title: Re: The Horizon is Always at Eye Level
Post by: rabinoz on May 19, 2018, 10:14:41 AM
Rather than look at the horizon drop from quite low altitudes, try it at about 43,000 ft.
Many modern aircraft have a Head Up Display (HUD) that shows the Attitude Indicator and other flight information on the windscreen.

This display clearly shows the horizon the expected angle below the local horizontal.
The first shows a sped up take-off climb and landing in a Bombardier Global 6000:
https://www.youtube.com/watch?v=LaW0lmwVUDA
Flight Global 6000 HUD EVS SVS, Wolfie6020
And this gives a bit of explanation:
https://www.youtube.com/watch?v=BLQhUX8brbA
Flat Earth - Yes the Horizon drops - Real aircraft footage - no fake CGI. Wolfie6020
Not that this sort of evidence will mean anything, it's the conspiracy!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 19, 2018, 03:08:36 PM
I was going to post a few pictures of intentionally tilted and skewed pictures of the water leveler and have Tom show me level.

But in doing so, I discovered something odd.

(http://oi65.tinypic.com/24o8xlx.jpg)

Why is that left (usually forward-facing) water not level? Yes, it's small but it's noticeable. I'm gauging square by the door panels in the background. They should give me a parallel line to the level line of the water tubes. But even when I level the apparatus all out and correct for any skewing angle, that one on the left side seems a tad higher.

I checked for any trapped air in the PVC elbows.

I didn't have this last night when I "calibrated".  Or maybe I did? Looking back with a more critical eye at those pictures comparing water level against a spirit level, maybe there IS a slight difference with the "forward" one showing a slightly higher level than the other?

(I did just check to make sure the door in the background was square and plumb. It is.)

I think I solved the riddle. The apparent rise followed the tube when I turned it around. So I took a closer look and the vinyl tubing I used isn't circular. It's more oval. Both tubes were cut from the same length of 2' tube, but when I constructed the apparatus, I twisted each tube into the PVC elbow and wound up with them at 90 degrees of rotation off. I never imagined that would matter. I just assumed the tubes were symmetrical.

I don't know the physics of why the water levels in the tubes would be different, but I think it's an illusion, created by the different angles looking through either the flatter side or the more oblong side. I tried squeezing the tubes into shape, but that's how they are formed or become warped, so if I'm going to use them, I just need to make sure they're facing the same way so that the sighting is made across the same surface.

I'm going to make some other mods while I have it disassembled. Can't leave well enough alone.
Title: Re: The Horizon is Always at Eye Level
Post by: jcks on May 19, 2018, 03:30:20 PM
I have been assuming that your camera is leveled exactly horizontally here. If the camera were fixed in a horizontal position the pixels need to match up in frame to ensure that the center of the lens was in line with the objects. You are right. I have been assuming that the camera was exactly horizontal. I was wrong to assume too much. If you are just tilting the camera willy nilly, there could be several issues with the leveling, enough that a pixel count is insufficient.

How am I supposed to know how much you are tilting your camera at and the altitude of the center of the lens?

Regardless, the illustration I have provided shows that this is a very sensitive experiment.

So I guess  this experiment (https://forum.tfes.org/index.php?topic=9338.msg145945#msg145945) is no longer valid then?
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 19, 2018, 03:55:37 PM
Do you have any rigid clear tubing that you could use? That way the cross section is equal, and the effect will be the same across both ends.

I do agree with your earlier statement though about not wanting to spend money. Tom wont spend a dime, so why should you!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 19, 2018, 05:26:00 PM
Do you have any rigid clear tubing that you could use? That way the cross section is equal, and the effect will be the same across both ends.
I have lengths of small diameter, flex tubing, yes. I started out with that in v1 of this project. I went with the larger diameter tubing because it was easier to see.

I think I'm going to separate the water leveling from the wire cube and treat them separately. I thought it would be helpful to combine the concepts to show they are complementary and back either other up. But maybe it's too much.

I've got an idea about how to refine the cube/perspective idea for establishing "eye level," and to focus on that, I'm going to keep the water tubing out of it. The cube, itself, will have to be precisely leveled and the eye/camera tuned to the view through it's center, but I think I have a way to do/show that.

As for the water level approach? I still like the concept. I'm just going to tinker with it a little more. It won't ever satisfy Tom since he's a skeptic of the principle or its ability to be precise enough to answer the question of this topic. But that doesn't mean I'm going to abandon it. I'm just going to find ways to refine it and maybe demonstrate that any margin for error is small enough above certain elevations that it won't make the "pass/fail" criteria of the claim ambiguous.

The trick to all this is arriving at a demonstration that is convincing as to where "eye level" is. If it's so precision-oriented, I don't know how Tom, et.al. can know where "eye level" is such that they can know the horizon always coincides with it. Not to mention, knowing the horizon you're looking at it "true."

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 19, 2018, 07:56:23 PM
Perspective only.

Centered vertical and horizontal sighting lines, both fore and aft:

(http://oi65.tinypic.com/16acjll.jpg)

Leveling of cube is essential:

(http://oi68.tinypic.com/a493zq.jpg)

If cube is plumb and square to level, obtaining a view or picture with fore and aft horizontal sighting lines aligned means the horizontal line is on a plane of "eye level"
Lines of perspective drawn from cube wires should converge somewhere on that line. If they don't, it means pitch isn't level. If lines converge below horizontal, then the cube is pitched forward and the camera is too high with focal plane is sloped downward. If they converge above horizontal, the cube is pitched back and the camera is too low with focal plane sloped upward.

With fore and aft vertical sighting lines also aligned, the lines of perspective should converge on the vertical line (less important for horizon measurement.)
Lines of perspective drawn from the cube wires should converge somewhere on the vertical line if camera centered laterally (and cube level). If lines converge left or right of the vertical line, then the camera is off center and the cub yawed left or right. This isn't critical for measuring horizontal plane, but to get all lines to converge on the center crossing of the vertical and horizontal sight lines, it is.

(http://oi63.tinypic.com/2wf4v91.jpg)

Debated with Tom previously about lack of importance of camera centering or orientation (pitch/yaw/roll). For this, it is significant if the pivot point isn't the center of the camera body; which it isn't. The pivot point for this tripod is below, and so when the camera is tilted forward, backward or side to side, it will in slight ways alter the height of the camera. (Yaw, or panning, without changing pitch or roll has no effect on height).

https://www.youtube.com/watch?v=soSTlPuH0wI

This isn't as simple as the water gauge. To make this work, the cube must be level in both fore/aft and left/right axes. The viewpoint must then be level with the horizontal sight lines. That establishes the eye level plane benchmark against which a horizon line is compared. Post editing of video image with lines of perspective will verify cage orientation if lines converge as expected.

Since leveling is best accomplished with a plumb bob, minimal wind is optimal. But even without a plumb bob, a bubble level checking multiple axes is sufficient. Just as the water "levels itself," the sight lines and the perspective lines can only line up correctly in one orientation. If something doesn't appear right, something is not level or aligned. It just takes more time to calibrate.

I'm going to treat the water level as a separate tool and remove it from the cube.
Title: Re: The Horizon is Always at Eye Level
Post by: rabinoz on May 20, 2018, 10:19:23 AM
The horizon might appear to rise to eye-level, but it does not quite rise to the local horizontal at the viewing point.

Here is more photographic evidence of this:
https://youtu.be/0jO6TUfiH8w
Flat Earth? Mountains rising to meet eye-level? Andrew Eddie
The opening screen does show only 0.523°, but at 2:55 the video has a more accurate calculation showing that from an altitude of 418 m the horizon is about 0.626° below eye-level.
That's not all that much less than the horizon Dip of 0.66° given by Metabunk''s Earth's Curve Horizon, Bulge, Drop, and Hidden Calculator (https://www.metabunk.org/curve/).

So the horizon does not rise to eye-level.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 20, 2018, 03:56:22 PM
If I'd seen that video earlier, I might never have bothered with this topic.

I'd been looking for something similar for San Diego, like an ocean horizon view from one of the inland peaks with something of a lower known elevations along the line of sight. But from many of the inland peaks, like Mt. Woodson or Cowles Mountain, the horizon is very fuzzy, which is typical of San Diego.

I turned back to the promotional footage that had been taken of the extravagant estate that went on the auction block a few years ago. It sits on a high promontory in north San Diego county coastal reach on a mount called Paint Mountain, which is only 1160', but with panoramic views of the surrounds, made available by the real estate agents and auctioneers.

(http://oi65.tinypic.com/2nkhooz.jpg)

Here, there's a definite horizon on a clear day. The only land rise on this W to SSW span is Mount Soledad in La Jolla, which is where I took my pictures recently.

(http://oi67.tinypic.com/2lb2b7k.jpg)

If the horizon is at eye level from the 1160', then Soledad at 823' should not be seen to rise above it. Yet it does. Doing the math is fun, but in a pass/fail test, all we need to answer is does the horizon always meet the plane of eye level? Every time we can measure or test it, it does not. I have yet to see a single demonstration or experiment that shows otherwise. It's an assertion, oft repeated in support of a flat earth, that doesn't have any supporting evidence as far as I can find.

Except for the low-elevation, anecdotal documentation found in Earth Not a Globe.
Title: Re: The Horizon is Always at Eye Level
Post by: rabinoz on May 21, 2018, 12:59:38 AM
If I'd seen that video earlier, I might never have bothered with this topic.
I posted that video because I've been to Flaxton Gardens and seem Mt Coolum many times, but never personally thought to check this out.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 21, 2018, 03:04:50 AM
If I'd seen that video earlier, I might never have bothered with this topic.
I posted that video because I've been to Flaxton Gardens and seem Mt Coolum many times, but never personally thought to check this out.

For marine navigation we use the formula using standard refraction as;
Dip in arc minutes = 1.78 multiplied by the square root if the observers height(in metres)

This would give dip to the horizon of 36.2 arc minutes or 0.606 degrees, a similar figure.

Considering that the top of the mountain is in TRANSIT with the horizon, which is very clear and sharp, it does somewhat show that the horizon is dipping.....
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 21, 2018, 08:06:25 AM
If I'd seen that video earlier, I might never have bothered with this topic.
I posted that video because I've been to Flaxton Gardens and seem Mt Coolum many times, but never personally thought to check this out.
It's a great video with solid analysis. Would be interested to hear what the rebuttal is, if any.
This is now the 5th way to show horizon dip.
I was at the seaside at the weekend and thought about downloading a theodolite app and seeing if I could get some pictures from a cliff but then I found you have to pay for the app!
It's not that expensive, but seemed like a waste for something I'd rarely use again. As it happened it wasn't the clearest day and the horizon wasn't that sharp anyway.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 21, 2018, 06:47:35 PM
https://www.youtube.com/watch?v=soSTlPuH0wI

Any criticisms/critiques of using this device to gauge "eye level" vs the horizon line?
Are there any precision issues that need to be considered. (Tom?)

I'll set this up on a stable tripod. Level it.
And then set up a camera also on a tripod, some distance behind, sighting through the cube toward the horizon.

Camera vertical "centering" will be vital, gauged by lining up the fore and aft horizontal sighting strings by adjusting camera height. Though camera pitch/roll/yaw is less important, due to the ball axis point of rotation, pitch and roll will, in very small measure, alter camera height by 1mm or less. So, just to avoid question, I will set the camera level as well so that it's focal plane is coincident with the horizontal and vertical planes of the leveled sighting cube.

Given that set up, there should be no question that the sight line constitutes "eye level." Any forward or backward pitch of the cube will be evidenced by the orthogonal lines of the cube not converging to the crosshairs of the sight lines. Any deviation of camera height will be evidenced by the horizontal fore/aft sighting strings not aligning. (Any deviation from center laterally will be evidence by the vertical fore/aft sighting strings not aligning, those this won't impact horizon measurement; only where lines of perspective converge on the horizontal plane...it's an aesthetic issue.)

The final calibration issue, then, is the sighting strings themselves. They must all be centered on the cube, at the midpoint of the middle space of the orthogonal grid wires. They aren't fixed. They are under tension using a midshipmen's knot, and will be positioned visually, and then measured and adjusted to be equidistant from the top and bottom (or left and right) of the whole cube and the two adjacent parallel wires. Precision of that measurement will be +/- 0.1mm.

How far should the setback of the camera be? Is 36" from cube centroid to camera lens sufficient? How accurate does that need to be? +/- 10cm okay?

The thickness of the strings. Is that within tolerance? (I forget what it is, but it's well earlier in this topic and about 1mm if I remember correctly.)

Anything else? What kind of visibility should I wait for for confidence that I'm seeing the "true horizon." I see a sharp horizon today with a cloud ceiling of about 5000', but visibility is reported as 10 miles. According to spherical earth calculations, that's is less than distance to the visual horizon, so it's no-go. But I don't know how to calculate a flat earth horizon distance such that I know visibility is sufficient. Can I have any cloud cover, as long as surface level visibility is clear?

I'd like to have as much input and feedback as I can BEFORE I report observations using this tool. It's harder to set up than the water level, but it ought to be easier to read and interpret. (I think.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 21, 2018, 09:20:52 PM
Or how about a simple "infinity pool" sighting tool:

(http://oi65.tinypic.com/9qgvig.jpg)

You can see the water tension at the lip, but the water across the length should be a level sighting surface. Yay? (Won't work with wind.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 22, 2018, 09:56:37 PM
Clear horizon!
I don’t have my toys with me, unfortunately.
But I do have the Hunter Research theodolite app. I’ll see if I can’t collect some observations at various elevations from sea level to 400’.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on May 22, 2018, 11:13:37 PM
Be sure to calibrate it right: bloody difficult, I found.

Best way seemed to be at sea level and set it to zero with the horizon there.

It may not give you perfectly accurate angles, but it will reflect perfectly that the angle you look down to the horizon at increases in tandem with your elevation.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 23, 2018, 12:08:49 AM
Be sure to calibrate it right: bloody difficult, I found.

Best way seemed to be at sea level and set it to zero with the horizon there.

It may not give you perfectly accurate angles, but it will reflect perfectly that the angle you look down to the horizon at increases in tandem with your elevation.
You're right. I had calibrated it yesterday, but today the roll angle was way off. Pitch angle looked like what I'd expect (for a globetard), but if there's anything wonky, I don't want to submit it for inspection.

The elevation numbers are all off too, by a consistent amount. I'm going to assume elevations are coming from GPS, so I figure they are grain-of-salt figures.

I may try again on my way home from work. No promises though.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 24, 2018, 01:10:10 AM
It's not my objective to measure any difference between horizon and eye-level. I only want to know if its possible to ascertain that there is (or isn't) a difference with increases in elevation.

After painstakingly calibrating this theodolite app (which has a thick crosshair and is gradated in 0.1° increments which I can't determine where they increment (midpoint rounding? threshold crossing?), I gave it a try today, sighting on the smaller Middle Coronado Islands, 17.5 miles south of the old lighthouse on Point Loma, from an elevation of about 410' (+/- 10):

Point Loma
H=400ft
estimated (globe earth) visual horizon=129369ft
anticipated angle=89.82°
anticipated "dip"=(00.18°)

(https://4.bp.blogspot.com/-JoWiOXmUYCo/WwYCrMawwMI/AAAAAAAAJy8/cRFReRDhpvoDyH6fZ3P-_0ersqj5VG1hQCLcBGAs/s1600/Coronados%2B5.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 24, 2018, 01:15:29 AM
And given that the summit of the larger of the 2 islands in the frame is right about 400' also, I tried to sight the cursor on its peak to obtain "eye level"

(https://1.bp.blogspot.com/-cZ-KJqWL_4E/WwYCrJgb7_I/AAAAAAAAJzA/HOqKAf31-ckhcWrlub67WkWu_Tn9ntIDwCLcBGAs/s1600/Coronados%2B7.jpg)

The app was cycling between 00.0 and -00.1, but simply pushing the button to get the screen cap would push it over whatever threshold it has to roll over to the first increment of negative pitch.

Bottom line is the apparent horizon is not inline with the summit of that island, which it should be if the horizon is at eye level.

Perhaps it's just not clear enough. I doubt it, but maybe the clearer the atmosphere gets, the closer the horizon will rise to that peak.

We'll see.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 24, 2018, 01:16:50 AM
Same location. Same time. Better camera.
(https://3.bp.blogspot.com/-HqTPYChOm3M/WwYL47yYVWI/AAAAAAAAJzY/Ct7bLwhsMGQQCDKCp49yZEDYF-UIgCWvwCLcBGAs/s1600/Coronado%2BHorizon%2B6a.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 24, 2018, 01:21:34 AM
Not taken today, and not by me, and not at the same elevation (aerial shot), but this is the view looking back toward San Diego from those islands. Point Loma is the mound above the horizon, just right of center of the frame:
(https://3.bp.blogspot.com/-ag7G5kg_59E/WwX7H-2F8pI/AAAAAAAAJyc/SoNoNK9NtjI7DOz6x-BrttCmDttdRw5cACLcBGAs/s1600/Coronados%2B3.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 24, 2018, 02:27:08 PM
This is the explanation of horizon (H) based on the "natural law of perspective" in Earth not a Globe (http://www.sacred-texts.com/earth/za/za32.htm)
(http://www.sacred-texts.com/earth/za/img/fig75.jpg)

This is an elaboration of what Rowbotham is explaining, and how to calculate distance to H on a flat earth surface:
(http://oi67.tinypic.com/126d9xf.jpg)

Observer height (eye level) in this picture is 410'. The distant island height is at the same height.
The calculated distance to H from a viewpoint of 410' according to this flat earth calculation is 260 statute miles.
If true, then the clearer the visibility to the horizon, the higher up the elevation of that island the horizon line will appear, until reaching a maximum level with the peak (level with the eye):

Same location. Same time. Better camera.
(https://3.bp.blogspot.com/-HqTPYChOm3M/WwYL47yYVWI/AAAAAAAAJzY/Ct7bLwhsMGQQCDKCp49yZEDYF-UIgCWvwCLcBGAs/s1600/Coronado%2BHorizon%2B6a.jpg)

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 24, 2018, 07:48:17 PM
Now that I've discovered this natural eye-level viewpoint, I'll watch for varying surface visibility conditions and check/photograph that Central Coronados island and see how much the horizon shifts vertically, and if it ever approaches eye-level.

[deleted original graphic; updated and corrected later in this topic and attached below.]

From yesterday (5/23/2018):
(http://oi65.tinypic.com/2e4ln2r.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on May 24, 2018, 09:20:18 PM
So am I reading this right?

(https://i.imgur.com/gvvzSnX.jpg)

The top line is eye level; the bottom line is where the horizon only appears to be because of haze and perspectives and optics; and the space in between is actually supposed to look like the sea, and it's just coincidence that it looks like the sky?

Is that how Rowbotham had it?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 24, 2018, 11:13:56 PM
(https://i.imgur.com/gvvzSnX.jpg)

The top line is eye level; the bottom line is where the horizon only appears to be because of haze and perspectives and optics; and the space in between is actually supposed to look like the sea, and it's just coincidence that it looks like the sky?

The top line is estimated to be eye level. I'm going to work out what the potential margin for error is because I'm not absolutely sure what the height of the island is. I'm going off one a single topo chart, and comparing photographs. Wikipedia has got to be wrong since it claims the two islands are close to the same elevation, but obviously they are not, and the topographical chart disagrees as well. But if that larger island isn't 4x the elevation of the "pile of sugar," what is it at least? 2x? Could it be 200-300' and not 400'? Right now, my leveling tools are leaning me toward 400', but I don't want be biased.

The observation point could be 400-420'. There are no benchmarks nearby and I'm just going by what all the literature AND the topo map says for that spot. Plus, I have to figure about +3' since I'm using a low wall to steady my shots on.

But for now, yeah. that larger island summit is likely close to eye-level.

The bottom line is the apparent horizon. Visibility is better today, despite an overcast ceiling of 2500-3000'. That's actually kind of nice because instead of a vast expanse of blue, the backdrop is white with a known height. So that "ceiling" at 2500' won't obscure a horizon from a perspective of 400'. It'll converge with the horizon, but much further away according to EnaG reasoning.

(http://oi68.tinypic.com/m0bix.jpg)

I really don't anticipate the horizon line will climb any further no matter how much clearer the surface visibility becomes, but I can continue to watch and record. It seems close to the same today as it was yesterday, even though the horizon is (subjectively) sharper and the contrast between sea and backdrop is greater.


Title: Re: The Horizon is Always at Eye Level
Post by: MCToon on May 25, 2018, 01:43:56 PM
In the thread "Horizon rising to eye level and a foolproof way to measure it." Started by Tontogary, Tom Bishop makes this statement:

Quote
The best method would be to find an obstacle of a known height, set it a distance away, and then set the height of your camera to the height of the top of the obstacle. The camera, object, and horizon should make a straight line. The further the objects are located from each other, the better. The horizon should line up with to top of the object, and there would far fewer surveying errors since everything is set on the ground rather than being dependent on aligning angles in a device of unknown calibration or holding everything in your hands.

See here: https://forum.tfes.org/index.php?topic=9462.msg147849#msg147849

The only detail needed is to verify the viewing height and the top of the island height.

Bobby, you are now using an acceptable method to test with a pass/fail if the horizon is at eye level.  This is great progress.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 25, 2018, 02:04:22 PM
Bobby, you are now using an acceptable method to test with a pass/fail if the horizon is at eye level.  This is great progress.
Spoiler alert:
When Bobby does produce a photo where his height and the distant peak height are the same and the horizon is clearly below it Tom will
1) Question how Bobby knows that the heights are the same and argue forever that it can't be definitively verified or
2) Claim that the horizon is slightly hazy and thus claim that the "true horizon" is actually at eye level.

And round and round we go...

Title: Re: The Horizon is Always at Eye Level
Post by: model 29 on May 25, 2018, 05:26:30 PM
I started piecing together a water level out of some scrap stuff.  There's a 1500 foot mountain nearby with a view of a major city 60 miles away that is at sea-level. 

Tom should conduct this experiment so he can show us all how it is done properly since he has so many issues with how it is being done so far.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 02:28:47 PM
Calibrating:
(http://oi63.tinypic.com/adg9hj.jpg)

After much testing, I've resolved that the margin for error in sighting horizontal level through this device is 1/8" of camera height adjustment, within which I cannot distinguish high or low based on leveling of the pair of horizontal sighting strings.

My planned camera set back had been 36" but that produces a +/- margin for error 17.25 miles away of +/-162', which is nearly half of my observation elevation and that of the Central Coronados island. Even though I'm not trying to take sightings to verify the height of the island's summit, it illustrates the sensitivity Tom was talking about with these kinds of observations.

Moving my camera setback to 60" will make the margin of error more comfortable, especially since I'm not measuring the dip angle but just  assessing -- pass/fail -- if the horizon is at eye-level. This will just add some degree of assurance that the distant island's summit is, in fact, in transit with 400' level of the eye from the observation point.

(http://oi67.tinypic.com/2mo78dh.jpg)

I think I've done all the prep and planning. Gotten some preliminary photos. Now it's just a matter of watching to see if that horizon line ever moves upward , using those islands as an index (with my "perspective cube" as an aid.

If that island summit is eye level, and the horizon never rises to it, then the test verifies that the claim "the horizon is always at eye level" fails.
If the horizon does move, to within at least half of the island's height (allowing for about 194' margin of error), then the test verifies that the claim "the horizon is always at eye level" passes.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 27, 2018, 02:47:05 PM
The larger island is Middle Coronado yes?

Nautical charts show the max height to be 76.5M.

The smaller one to the right shows to be 30.7M high.

They are both below your elevation, therefore the horizon should actually rise above the higher peak..........
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 03:00:09 PM
The larger island is Middle Coronado yes?

Nautical charts show the max height to be 76.5M.

The smaller one to the right shows to be 30.7M high.

Is that info available online such that you can provide a link? Or, if not, a reference I can cite?

Wikipedia has them both listed at around 100', which you can tell just from my photos isn't right.
The only available topo chart I have doesn't list summit heights specifically, but gauging just from elevations lines, it suggests Central Coronados (the taller one) may breach 400' whereas Pilón de Azúcar (smaller one) is just 100'.

From aerial photos, and judging by the relative heights at distance (though Pilón de Azúcar is a little closer to Point Loma), I was suspicious that the larger was some height greater than 100' and less than 400'.  76.5m is about 250' which does seem to confirm that, and would not put it in transit with the horizon if the horizon is at eye level from a vantage point of 400-410' feet. So, it should make it easier for the "true horizon" to reach that transit line. That's a lower benchmark, but to make it sporting, I'll confer a "pass" on the test if the horizon reaches even that 250' summit mark.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 03:05:26 PM
^ Non-sporting-wise, I'll have to redo the calculations for "dip" angle from level and distances/margins of error, now that I have more confidence the larger island summit is lower than my observation point. I'm not sure I'll be able to find a viewing spot that is close to 250'. There's a road/path that the public is allowed to use the runs down closer to sea level, but I'd need a survey marker of some sort to know where 250' of elevation is along that road. (And I'd probably have to ask park rangers for permission to set up, which I'm rather not-inclined to do because I'd have to explain why.)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 27, 2018, 03:18:35 PM
I got the heights from a nautical chart of the area.

I am not sure if you can get an online edition of the chart, as they normally require a subscription.

The other place you may find it would be the US coast pilot. Again i am not sure if you can access it on line for free.

I can take a photo of the screen showing the chart, and height if you wish?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 03:25:16 PM
I got the heights from a nautical chart of the area.

I am not sure if you can get an online edition of the chart, as they normally require a subscription.

The other place you may find it would be the US coast pilot. Again i am not sure if you can access it on line for free.

I can take a photo of the screen showing the chart, and height if you wish?

Please? We'll call it Fair Use? You can just PM it to me.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 03:28:23 PM
Updated graphic:
(http://oi65.tinypic.com/9jpq4j.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 27, 2018, 03:35:52 PM
I got the heights from a nautical chart of the area.

I am not sure if you can get an online edition of the chart, as they normally require a subscription.

The other place you may find it would be the US coast pilot. Again i am not sure if you can access it on line for free.

I can take a photo of the screen showing the chart, and height if you wish?

Please? We'll call it Fair Use? You can just PM it to me.

Even better, I have a link, it is a free to view copy of the paper chart. It is an official link, and is ok to use.

Zoom into the chart about bottom middle and you will see the islands. Middle Coronado, and the little one just north of it, and the numbers in brackets will be the height.

Now it also shows North Coronado having a max height of 476 feet, so that would be much closer to your observation height, but i can see that Tom would just dismiss it out of hand as being higher etc etc. Best go for a lower height.
I am interested to see if there is ANY way that this can be nit picked to discredit the observation.

I am pretty certain that at no point will you ever see the horizon higher than the top of the islands.....

http://www.charts.noaa.gov/OnLineViewer/18765.shtml
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 27, 2018, 03:49:51 PM
When you have followed the link, do a new search for chart 18773, it will show you pretty good elevations around Lima point. There are some pretty good contours there, and at the Carrillo national monument there is a tower, right on the 400 foot contour, with what looks like a road nearby.

You obviously know the area and will know where you can get to. I only can read the charts.........
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 04:52:22 PM
Awesome! Thanks.

Looking at the chart for the tip of Point Loma, I think the public overlook just south of the old lighthouse is the best, and it does match to right about 400' or a bit more. Under 420' with tripod for sure. I feel like there ought to be a geodesic benchmark somewhere, but this is good enough.

That other "tower" on the chart is a fenced off facility for what looks like meteorological equipment and a microwave antenna or two. The public observations points are above the ground level where those are.

I looked around for other spots at 250' to maybe put Central Coronados in transit. I marked a few spots:

- The blue star is on a public path that goes down toward the bayside portion of the point, and if it weren't for that ridge I marked with a red line, it would be great.
- The green star is on federal property. I can get there, but I can't bring a camera. (Battery Humphreys is an old WW2 embattlement, used for other purposes now.)
- The orange star is on a public roadway that provides access to the windward coastal areas like the current lighthouse, tidepools and other federal facilities. There's no pull off area or stopping permitted. I think pedestrians are allowed on the shoulder to make the walk up/down the road, but not to stop and set up a tripod station. And there's no off road/trail hiking permitted. (Not fenced off, but posted.)

(http://oi68.tinypic.com/25khjtg.jpg)

As an aside, I was shooed away from taking photos from a vantage point further north from the tip (https://goo.gl/maps/xGvEzJSorUP2). It's on federal property and not behind gates, but I was asked what I was doing and told that though I'm permitted access, I can't use my camera since it overlooks federal facilities. That's what led me to check out the end of Point Loma in the 1st place. That was a great location, close to where I work and comfortable (picnic tables, shade, parking within feet...it was perfect.)  That had an elevation of about 400' also and I could see all of the Coronados, albeit adding around 2-3 miles to the distance and not affording any access close to sealevel.

I am allowed to take photos from the public pull off a few hundred meters north of that, above the TRANSDEC pool (https://goo.gl/maps/K9yg8krSZwA2), but I can't see the islands from there. It's still a good spot to view the horizon. When I've got my cube or my water level tubes set up on a tripod, I invariably have other motorists or cyclists stopping to ask what I'm doing. I probably should make up a poster board explaining. Even though I think this is proving to support a globe earth, the mere fact that it gives attention to a flat earth prospect has to be something The Flat Earth Society would appreciate.

Title: Re: The Horizon is Always at Eye Level
Post by: douglips on May 27, 2018, 05:42:26 PM
That person can't prevent you from taking pictures. You may not want to deal with it, but that person needs to review the rights of photographers.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 08:49:34 PM
That person can't prevent you from taking pictures. You may not want to deal with it, but that person needs to review the rights of photographers.
It's federal property. I'm not aware of any rights that permit trumping government facility security rules. The fact that it's posted as federal property but access is not controlled and no signage informing that photography is forbidden might give me an argument if they threatened to take my camera or penalize me for having snapped some photos, but I don't think I have any argument to claim I can stay and continue to photograph once informed.

And yeah, I'm certainly not going to fight it. I know of and agree to the no-photography rules without authorization on controlled property. I rely on continued access, so I'm not going to risk that. I just think it's not clear if those rules apply from that location.

There's an old adage that's sometimes applicable that goes along the lines of not asking a question where you might not like the answer. It goes "better to beg forgiveness than ask permission." I purposely didn't ask because I wanted to shoot from that spot, until someone said something. Then someone said something. So I'm not going to complain nor press it.

(I'd like to add that the security guys were very cool about it. Not like they were jackboots, even though I did say "I got booted." It was just a phrase. They pulled up, asked me what I was doing. I told them I was taking advantage of the view to photograph the islands. They kindly informed me that I couldn't do that on government property without a camera pass, which I could get from the security office with approval of my branch (which I ain't gonna ask for). So, I confessed I didn't know, since I thought I was off the controlled area. Offered to let them look at the photos to verify I wasn't trying to spy on the activities below behind the fence line, but they said no need. And they left, letting me stay to finish my lunch and enjoy the view. If I didn't have a badge, I probably would have been asked to leave, but they weren't jerks or intimidating. And I wasn't going to be combative either.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 27, 2018, 11:23:22 PM
The competing claims and their predictions, with the clearest photo so far:

(http://oi63.tinypic.com/vy6pev.jpg)

(http://oi66.tinypic.com/256sfn6.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: SiDawg on May 28, 2018, 05:31:01 AM
Hi I don't quite follow your logic with the islands appearing about the horizon... Again, I'm playing devils advocate (folks are going to think i'm a flat earther soon!)

But if horizon rises to eye level, they will surely just say that the islands along that line can have their tops above eye level? (the and first top above the bottom of the second top)

(https://i.imgur.com/5BCyvva.png)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 28, 2018, 06:27:22 PM
But if horizon rises to eye level, they will surely just say that the islands along that line can have their tops above eye level? (the and first top above the bottom of the second top)

(https://i.imgur.com/5BCyvva.png)
Not if they're tops are at the same height as eye level.

(http://www.sacred-texts.com/earth/za/img/fig76.jpg)

To borrow a Vegas slogan, "What happens at eye-level, stays as eye-level." How can an island peak be at eye level and also appear to be above eye level?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 28, 2018, 07:26:11 PM
From Mt. Soledad a couple of weeks ago. Observation "eye level" 800' (+/- 10'); at sunset:

(http://oi67.tinypic.com/5nnfb5.jpg)

Verifying eye level horizontal plane:

(http://oi64.tinypic.com/2pysuoh.jpg)

Catalina Island visible on horizon, 70-75 miles away:

(http://oi63.tinypic.com/69mh4m.jpg)

Identifiable peak elevations and their elevations:

(http://oi63.tinypic.com/2njbmef.jpg)

Line of the horizon is below these summits. Line of "eye level" is above.
Title: Re: The Horizon is Always at Eye Level
Post by: edby on May 28, 2018, 08:42:00 PM
OK just testing. How do you know that the line with the eye on actually is at eye level?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 28, 2018, 09:20:01 PM
How do you know that the line with the eye on actually is at eye level?

Clues are in the photograph:

(http://oi68.tinypic.com/ke84md.jpg)

The water level provides an indicator of horizontal. The orthogonal lines of the leveled cube converge on the line. If the cube was tilted forward or backward, the lines of perspective would converge above or below the level water line.
Title: Re: The Horizon is Always at Eye Level
Post by: edby on May 28, 2018, 09:27:20 PM
Oh I see. Didn't realise it was a water level.

Isn't this conclusive proof then?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 28, 2018, 09:34:32 PM
Oh I see. Didn't realise it was a water level.

Isn't this conclusive proof then?

I'd like to make more observations at different elevations and validate that this is repeatable and the "dip" is outside any margin for error. But, for me, it's trending toward conclusive.

But the point of this is that its something anyone could do. You don't have to rely on reports (or photos) of others. See for yourself.
Title: Re: The Horizon is Always at Eye Level
Post by: edby on May 28, 2018, 10:04:12 PM
Oh I see. Didn't realise it was a water level.

Isn't this conclusive proof then?

I'd like to make more observations at different elevations and validate that this is repeatable and the "dip" is outside any margin for error. But, for me, it's trending toward conclusive.

But the point of this is that its something anyone could do. You don't have to rely on reports (or photos) of others. See for yourself.
Yup. No CGI, satellites etc required.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 28, 2018, 10:15:32 PM
Oh I see. Didn't realise it was a water level.

Isn't this conclusive proof then?
It is, but Tom will find some spurious objection while refusing to get out there and do any observations himself.
I like that these photos are at sunset, so it can't be sensibly claimed that the "real horizon" is actually in the sky as was claimed for other photos.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on May 29, 2018, 01:16:42 AM
That's very good, Bobby: a great little tool for conclusively showing that, at elevation, eye level is not level with the horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: SiDawg on May 29, 2018, 06:28:08 AM
Would also love to hear how the supposed "Electromagnetic Accelerator" makes light bend upwards beneath the clouds... in a U shape?
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on May 29, 2018, 07:09:14 AM
Would also love to hear how the supposed "Electromagnetic Accelerator" makes light bend upwards beneath the clouds... in a U shape?

I dont want to give them ammunition, but i am sure they will say something daft like reflected off the ocean......
Title: Re: The Horizon is Always at Eye Level
Post by: Curious Squirrel on May 29, 2018, 01:04:40 PM
Would also love to hear how the supposed "Electromagnetic Accelerator" makes light bend upwards beneath the clouds... in a U shape?

I dont want to give them ammunition, but i am sure they will say something daft like reflected off the ocean......
For the record that WAS one of the suggestions during the thread on it: https://forum.tfes.org/index.php?topic=6875.0

Also do note, according to Tom at least, most of the FES has given up support of the EA and it has been left in the wiki for historical purposes. I can try to dig up the quote if you like.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 29, 2018, 05:30:22 PM
Not my photo. Found it online. Clear day. Not zoomed, but horizon still below the tops of all islands from an elevated viewpoint on Point Loma. (New lighthouse near sealevel in the lower right corner.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 29, 2018, 05:33:18 PM
Also not my photo; but my annotations.

Photo is from Mount Soledad looking past Point Loma toward Mexico's Coronado Islands.

(http://oi65.tinypic.com/2a6ov21.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 29, 2018, 05:55:37 PM
Grain of salt time, but since I took the photo on the right (so I know the details) but I find no embedded information on the photo on the left.

But, estimating by eye, my photo, looking westward from Mount Soledad and the other one, looking south from same elevation, seem to be at the same focal length.

So, comparing side-by-side, this COULD (emphasis on "could") be a fair extension of my eye-level measurement with the Coronado Islands view.

The South Coronado island is about 100' lower than the summit of Mount Soledad in La Jolla.

Horizon and "eye-level" are well apart, in both images.

(http://oi68.tinypic.com/2czu3qp.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: LersmenThe3 on May 29, 2018, 08:08:27 PM
I don't think you're going to notice a difference of 5' 7" at a 2.9 miles
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 30, 2018, 01:11:54 AM
Also not my photo; but my annotations.

Photo is from Mount Soledad looking past Point Loma toward Mexico's Coronado Islands.

(http://oi65.tinypic.com/2a6ov21.jpg)
Antsy for good viewing weather.

Took a quick side trip to Mt Soledad on drive home, even though I knew the visibility was poor. Found the same spot where this other photograph was taken.  Can't make out a horizon line or see any off shore islands.

(http://oi67.tinypic.com/99l3qq.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Gazza711 on May 30, 2018, 07:35:36 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.
Am i missing something here? Is there another gazza711 as im new here?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 30, 2018, 10:00:48 PM
(http://oi64.tinypic.com/2ni8ae1.jpg)

Photo from within 10' of sealevel, at near low tide.

Clear horizon, but is it "true?"  Note that the tip of Pilón de Azúcar seems to be floating above the horizon.

Also, if that little rocky island, 16.9 miles away from where this 10' above sea level photo was taken (https://goo.gl/maps/mPwPBsBtAa62) is really just 101-108' at its summit, it should not be visible at all. But with just standard refraction, as much as 10-15' of the island's highest elevation is predicted to be visible.

Where is the true horizon?
Title: Re: The Horizon is Always at Eye Level
Post by: Theo on May 30, 2018, 10:25:18 PM
It's pretty obvious to me where the horizon is and even more so if you adjust the contrast...

(https://i.imgur.com/AJIY3nD.jpg)

https://i.imgur.com/AJIY3nD.jpg

That's a pretty sharp separation between water and sky even without adjusting contrast.
It's almost as sharp as between the water and the ship 
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 30, 2018, 10:56:56 PM
That's what I thought, and I agree that it's sharp. But is it the actual horizon or just an apparent one?

There's a mirror effect in the distance. Is that mirroring masking the true horizon or is it masking what should be visible of the islands?

My answer is that the actual horizon is at the level where the "mirroring" takes place, meaning it's above that sharp line slightly.

It's like this example of an inferior mirage during sunset.

(http://aa.usno.navy.mil/graphics/sun2b.jpg)

It looks like the horizon is where the sea meets the sky, but the sun reveals the inversion layer and gives you a mirror image of the lower limb of the sun rising up to merge with the setting sun. That merging point is where the actual horizon is.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 30, 2018, 11:14:49 PM
To be clearer:
(http://oi64.tinypic.com/3v2ie.jpg)

This is exhibiting an inferior mirage, I believe. The lower band (above the apparent horizon) is a mirror image of the upper band. It reveals itself with the islands, where the red is an inverted image of the black. But without any distinguishing characteristics of the water line, the "mirror" blends and you can't detect the "fold."

So, the question is, if that inversion effect wasn't there and the mirage disappears, what would you see in that lower band?  Between the islands, would we see more sea, as if the horizon line were higher? Or background sky, meaning that sharp line we do see is aligned with the actual horizon? On the islands, would you see lower elevations of the island or would the line of the sea rise to that level?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 30, 2018, 11:32:48 PM
Same day, but at a higher elevation (400'):

(http://oi68.tinypic.com/m0bix.jpg)

Now, I don't see the mirage effect, but that's probably because my angle is penetrating the inversion layer at too steep an angle at the distance of those islands. The sharp horizon is now beyond that distance, further away, and I have nothing on the horizon to see if there's a "mirror" effect where my sight line is tangent to the surface.

But even if it were, it'd be far enough away that, geometrically, I don't think it would make an appreciable difference between "true" and "apparent" horizon.

So far, in my short observation period, I've never seen the horizon appear above this little "ledge" on the larger Central Coronado island.

(http://oi65.tinypic.com/32zj495.jpg)

I labeled that "actual," but maybe it should be "apparent" since I know there's a temperature inversion and likely an inferior mirage. Though at the distance the horizon would be at from that viewing elevation, the band of mirage would be miniscule and not really change the level of that horizon line much if any.

Nowhere close to "eye level" anyway, which on a flat plane would be above the summit of the larger island. I'm just trying to give "horizon at eye level" claimants every possible benefit of doubt.
Title: Re: The Horizon is Always at Eye Level
Post by: Theo on May 31, 2018, 02:01:56 AM
Bobby I don't think you're dealing with a mirage.  Wouldn't you expect the same effect to occur on the lower part of the Island on the left? They are very close to the same height.  I think your are seeing the top of the rock on right due to refraction not mirage. 

(https://i.imgur.com/LiP75oe.jpg)
https://i.imgur.com/LiP75oe.jpg

Also wouldn't a mirage appear opposite of your example?  The 2 pyramids being mirrored point to point?

My compliments Sir on your efforts and especially the water level apparatus. 

You already proved the shape with the fact that you see more of the Islands as you rise in altitude
 
(https://i.imgur.com/Jc7siJy.jpg)
https://i.imgur.com/Jc7siJy.jpg

I guess this is just icing on the cake?   ;)

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 31, 2018, 05:21:58 AM
Bobby I don't think you're dealing with a mirage.  Wouldn't you expect the same effect to occur on the lower part of the Island on the left? They are very close to the same height.  I think your are seeing the top of the rock on right due to refraction not mirage. 
No doubt, refraction is making that island tip on the right visible, but an inversion layer is distorting it, as well as the portion of the island on the left that is coincident with the inversion layer:

(http://oi63.tinypic.com/30svwit.jpg)

The white line in the upper image is where I think the horizon is. Above it, to the yellow line, is real and what is being inverted in an inferior image from the white line to the red line, where an apparent horizon is.

In the lower image, taken from 400' higher, we can see what the islands really look like below that white line, and it's not what's in the upper picture between the white and red lines. The inferior mirage elongates, undercuts or even makes the tip of the small island appear to float. But that's because instead of the real image, it's an inverted image of the same band above the white line.

My question, without the inversion and it's inferior mirage, what would appear between the white and red lines in the upper picture? Would it be the slightly lower elevations of the islands? Or would it be the water line?

My guess is the waterline, which means the white line is where the actual horizon is and not the red line, which is the apparent horizon. The inferior mirage depresses the appearance of the horizon just slightly.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 31, 2018, 09:19:19 AM
A distant cousin, Tom?

Facebook photo of Islas de Coronados (https://www.facebook.com/photo.php?fbid=10216163298585639&set=p.10216163298585639&type=1&opaqueCursor=AboerZ63bQMCliI4IHsY77Oe0fsybeeU2tjfzvNW2NHNJLFui1KfkToFLUoalatgpNVYI-C91vWXZ1VR5dcAEqERq23qJ3AUlpn0kXX_MtrlU6jpfTyfE1sBkpBOEzZ5n8gBAnNf1qf37AcITCIWfjMOQpMe9bNWiNEoW2enaEAM965OiECqmN7nPQwT-Jc16cb5DUbnFLupOGa8rmHAIthOilJawTbF5Rik51Hx4jOeGXffv3hQ0L8pbxpdLKyU4uF49RurW4erxpmZ70jleGUAPzKObRGfXoNp5O1ql1HgEw9SqD0pFc-5rxMGHV3ARByoIaHq8B46KMtCZLsIpSEmISLA_q23gbLKRtRQBMvuzpqWNFohy5RrytSBhQwHcebRjeUICi-w62V8samRQryqenEApyFVwtLk76G9xHxlnuJ6hM7j9oaLP6WHj8JV7KdGvTsPCCFyLvT34OAGEQf0&theater)
Title: Re: The Horizon is Always at Eye Level
Post by: HorstFue on May 31, 2018, 11:54:30 AM
FES links one of the best examples for mountains sticking out above the horizon in the Wiki:
https://wiki.tfes.org/A_view_from_Everest

No other point on Earth is higher than Mount Everest. So if horizon is at eye level, you should not see any other mountain stick out above the horizon ...
You may have to turn around the panorama view a bit, to find one rather close and others in the distance.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on May 31, 2018, 03:16:59 PM
FES links one of the best examples for mountains sticking out above the horizon in the Wiki:
https://wiki.tfes.org/A_view_from_Everest

No other point on Earth is higher than Mount Everest. So if horizon is at eye level, you should not see any other mountain stick out above the horizon ...
You may have to turn around the panorama view a bit, to find one rather close and others in the distance.

It's not quite clear what you mean here. The distance to the horizon depends entirely on the height of the observer above sea or ground level. Whether you can see a mountain or not depends on how close you are to it, and how tall it is. Not sure how Mount Everest comes into it.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on May 31, 2018, 03:28:48 PM
FES links one of the best examples for mountains sticking out above the horizon in the Wiki:
https://wiki.tfes.org/A_view_from_Everest

No other point on Earth is higher than Mount Everest. So if horizon is at eye level, you should not see any other mountain stick out above the horizon ...
You may have to turn around the panorama view a bit, to find one rather close and others in the distance.

It's not quite clear what you mean here. The distance to the horizon depends entirely on the height of the observer above sea or ground level. Whether you can see a mountain or not depends on how close you are to it, and how tall it is. Not sure how Mount Everest comes into it.
If you are on top of Everest then you have to be looking down on everything else, yes?
So if the horizon is at eye level then the horizon would have to appear above all the other peaks around you.
The only thing is the same problem as from a plane, at that height the horizon is often not that clear.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 31, 2018, 05:18:41 PM
Even though it's overcast, it might be a good day for some Sunset Cliffs horizon observations:

(http://oi67.tinypic.com/t54m83.jpg)

Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on May 31, 2018, 10:48:12 PM
May 31st, 2018 12:31 PDT
Location: 32°40'30.1"N 117°14'46.3"W (https://goo.gl/maps/1JrxVAwjNe92)
Elevation: 100' (+/- 5')
Photo: Original 4000x2248 jpg (https://drive.google.com/open?id=1IMXIL_7r4jVrgmTy7CqiXgBPS2h0KL7h) (2MB)

(http://oi66.tinypic.com/b70zz6.jpg)


May 31st, 2018  13:30 PDT
Location: 32°40'22.5"N 117°14'30.7"W (https://goo.gl/maps/sRv61heVrUA2)
Elevation: 400' (+/- 10')
Photo: Original 4000x2248 jpg (https://drive.google.com/open?id=1XuAO7q1dCtFZ1KGwLFZpNnAuN9R2CXdB) (2MB)

(http://oi63.tinypic.com/az9fsx.jpg)


Bonus: tried water level device at the lower elevation. Did not put it to use at the 400' site. Will give it a try at 800' later:
(https://4.bp.blogspot.com/-pt3UfRzvZ_E/WxB88tUXuGI/AAAAAAAAJ1Q/tsjpjCtbm486Fbqq8cTXaxkus2Q6vYMdwCLcBGAs/s1600/IMG_0147_sm.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 01, 2018, 01:40:37 AM
Annotated:

(http://oi66.tinypic.com/24whidj.jpg)

(http://oi66.tinypic.com/xfck06.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on June 01, 2018, 08:41:09 AM
Can't help noticing that most of the perspective lines you've drawn don't follow the lines of the cage.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 01, 2018, 12:37:08 PM
Good eye. That one turned out warped. I constructed it on site and couldn't get it square.

I drew the lines of perspective from the weld points: half from the rear (yellow) and half from the front (white).  I think it's the two side panels that are bowed or torqued. The lines are straight on the panels themselves, but when put together, there's a slight rotation. It doesn't alter the pass/fail results, but it's not tidy.

The forecast says I should have clear skies this afternoon, so I'm going to try again but with my other cube.

I'm also going to try to get some fluorescent-colored string. Trying to find and align that white twine through the camera is tough.

(What I had done was create a port-a-pack of components to make it easier to carry on a hike, and then construct the cube at a sighting location. It only takes about 10 minutes and makes it easier than lugging it up a trail. I still like the idea, but seeing the results, I don't think I need to make the hike up to the higher elevations, and I didn't anticipate that subsequent cubes might not build out as well as the first. Live and learn. Part of the fun.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 01, 2018, 02:46:55 PM
Today is shaping up to be a good viewing day, so I'm going to make "official" observations for 100', 400' and 800' using both the cube and the water level.

 I appreciate all of the commentary since the start of this topic. If there are any lingering concerns or suggestions, feed them to me now, if you please.
Title: Re: The Horizon is Always at Eye Level
Post by: MCToon on June 01, 2018, 04:45:07 PM
Today is shaping up to be a good viewing day, so I'm going to make "official" observations for 100', 400' and 800' using both the cube and the water level.

 I appreciate all of the commentary since the start of this topic. If there are any lingering concerns or suggestions, feed them to me now, if you please.

Bobby, your leveled cage is quite similar to the method used in EnaG Experiment #11 where Rowbotham didn't trust a theodolite and instead used an 18 inch iron tube:

"He therefore obtained an iron tube, about 18 inches in length; one end was closed, except a very small aperture in the centre; and at the other end cross-hairs were fixed."

Your descriptions are much more thorough than the descriptions in EnaG.  For example, he doesn't provide specific locations, just "...in various places, and at different altitudes...".  This ambiguity makes Rowbotham's experiments impossible to reproduce, yours are very reproducible.

I cannot see anything wrong with your setup.  It is almost identical to Rowbotham's method in experiment 11.  This should be acceptable for any EnaG adherent.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 02, 2018, 12:07:50 AM
Not a cloud in a beautiful blue sky, but the horizon has been a blurred haze all day, despite aviation and maritime wx calling it 10+ miles visibility.

Just not the right time of year here, so I'm going to table this "experiment" and report back after I get a good opportunity to record some non-ambiguous observations with my toys.
Title: Re: The Horizon is Always at Eye Level
Post by: Gazza711 on June 02, 2018, 06:31:04 AM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.
who's gazza711
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on June 02, 2018, 07:27:01 AM
Not a cloud in a beautiful blue sky, but the horizon has been a blurred haze all day, despite aviation and maritime wx calling it 10+ miles visibility.

Just not the right time of year here, so I'm going to table this "experiment" and report back after I get a good opportunity to record some non-ambiguous observations with my toys.
I honestly think you've done more than enough already. I note that there has been no FE response to your more recent photos, since some are at sunset there is no way to sensibly claim that the "true horizon" is further away and thus higher.
In the real world this is how progress is made. A hypothesis is suggested (that horizon is always at eye level regardless of altitude), an experiment is done to test that hypothesis, the results either add confidence to that hypothesis (note, not prove) or disprove it. So if your experiments showed the horizon at eye level then it would add confidence to the assertion that horizon is always at eye level. It wouldn't prove it, what if you go higher? The more experiments you do from different altitudes all showing the horizon at eye level, the more confidence you would have.
But your photos don't show that, they very clearly show that horizon dips, and dips more the higher you go. This matches the RE hypothesis and adds confidence to the RE model.

It is frustrating that the FE response so far has been "la, la, la, can't hear you" or just trying to find any tiny seed of doubt to claim your experiments are invalid with no attempt to do any experimenting themselves. But whatever, to pretty much everyone else you have done more than enough to disprove the assertion that the horizon always rises to eye level. Good job, as you Americans say. (English translation: "Well done, old bean" ;) )
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 03, 2018, 01:53:59 AM
Thanks. And I'm perfectly fine with the nitpicking. It's always good to be challenged. Helps with refinement, and limiting tendencies to just explore for answers you like.

Oh, and I stumbled across a live webcam at Pacific Beach (http://www.pacificterrace.com/webcam.aspx#gref).

(http://oi65.tinypic.com/ezmidj.jpg)

I can use this to see how clear the horizon is before trekking out with my gear. Plus, it pans past a palm tree that has a little identifiable indent right that we can use as a crude index to see how much the horizon rises or falls with visibility, all from the comfort of a keyboard.



It doesn't really help with the "eye level" question, but it can help with confidence what the "true horizon" is.
Title: Re: The Horizon is Always at Eye Level
Post by: junker on June 03, 2018, 02:56:50 AM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.
who's gazza711

Refrain from low-content posting in the upper fora. Warned.
Title: Re: The Horizon is Always at Eye Level
Post by: Westprog on June 04, 2018, 04:04:05 PM
It is frustrating that the FE response so far has been "la, la, la, can't hear you" or just trying to find any tiny seed of doubt to claim your experiments are invalid with no attempt to do any experimenting themselves. But whatever, to pretty much everyone else you have done more than enough to disprove the assertion that the horizon always rises to eye level. Good job, as you Americans say. (English translation: "Well done, old bean" ;) )
[/qu

I think you're missing what the purpose of this experiment was. It wasn't primarily to show that the horizon does not, in fact, rise to eye level. We knew that before, and the claim that it does had no supporting evidence and didn't even make any consistent sense to begin with. We knew what the results of the experiments would be. What was really interesting was to see how the FE proponents would deal with the problem of having one of their beliefs disproved.

I know it seems frustrating to not get any kind of engagement with the argument -  but we need to accept that this won't happen, and indeed, it can't. That's not what's going on here. Look at how the perspective thread was moved out of the debate forum because nobody was interested enough to debate it. (Another piece of excellent work which left me a lot better informed.)

I'll add my own congratulations to Bobby Shafto for an excellent piece of work - and he shouldn't feel frustrated at any failure to convince anyone. That's not possible, and thinking it is will just lead to frustration.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 05, 2018, 06:07:46 AM

(https://4.bp.blogspot.com/-pt3UfRzvZ_E/WxB88tUXuGI/AAAAAAAAJ1Q/tsjpjCtbm486Fbqq8cTXaxkus2Q6vYMdwCLcBGAs/s1600/IMG_0147_sm.jpg)

This was taken on June 1st when the horizon was moderately clear, but not super sharp.

These were some photographs taken during the same session: same day, same conditions...

(http://oi64.tinypic.com/2myb80z.jpg)

(http://oi67.tinypic.com/2cf9unl.jpg)

(http://oi68.tinypic.com/zxprgo.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 05, 2018, 06:25:00 AM
I've been trying to confirm (https://forum.tfes.org/index.php?topic=9777.msg154734#msg154734) if I'm understanding the EnaG (http://www.sacred-texts.com/earth/za/za32.htm) and TFES Wiki (https://wiki.tfes.org/Viewing_Distance) explanation for the horizon (H), and how to calculate its distance from the observer for a given height above the surface.

(http://www.sacred-texts.com/earth/za/img/fig83.jpg)

Distance to H in a flat earth topography has confounded me. I thought I had it figured out, but the calculated distance doesn't mesh with reality. For instance, at 100' viewing elevation it seems that H on a flat surface should be around 65 miles. By contrast, on a globe earth, it figures to be about 13-14 miles, and that's with the help of refraction. 13 vs 65 miles: that's a significant difference.

On June 1st, when the photos above were taken, the horizon was sort of sharp, but certainly not 65 miles worth of sharp. This lack of certainty about whether or not I'm seeing the "true" horizon has made observing whether or not the horizon always rises to eye-level rather elusive.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 05, 2018, 06:45:22 AM
But take a look at that last photo I posted from June 1st.

(http://oi65.tinypic.com/27xfqqb.jpg)

Is that ship at or beyond Flat Earth H distance?  If so, then that must be the "true" horizon (which wasn't at eye-level). If not, then it's lower hull shouldn't be yet merging with a "convergence zone."
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 05, 2018, 02:47:06 PM
...I stumbled across a live webcam at Pacific Beach (http://www.pacificterrace.com/webcam.aspx#gref).

I can use this to see how clear the horizon is before trekking out with my gear. Plus, it pans past a palm tree that has a little identifiable indent right that we can use as a crude index to see how much the horizon rises or falls with visibility, all from the comfort of a keyboard...

It doesn't really help with the "eye level" question, but it can help with confidence what the "true horizon" is.

A few days worth of horizon checks:
(http://oi67.tinypic.com/110x6w1.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on June 05, 2018, 03:18:21 PM
...I stumbled across a live webcam at Pacific Beach (http://www.pacificterrace.com/webcam.aspx#gref).

I can use this to see how clear the horizon is before trekking out with my gear. Plus, it pans past a palm tree that has a little identifiable indent right that we can use as a crude index to see how much the horizon rises or falls with visibility, all from the comfort of a keyboard...

It doesn't really help with the "eye level" question, but it can help with confidence what the "true horizon" is.

A few days worth of horizon checks:
(http://oi67.tinypic.com/110x6w1.jpg)

I would say the horizon is pretty steady. It does not appear to move up or down, just sharpens somewhat.

Good luck within the observations
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 05, 2018, 05:04:22 PM
I would say the horizon is pretty steady. It does not appear to move up or down, just sharpens somewhat.

Good luck within the observations
The counter-intuitive one is the brightest day didn't have a cloud in the sky, but that was the one day where the surface marine haze off the coast "lowered" the apparent horizon.

I've also become aware, after observing the Coronado Islands, that there is a standard inversion this time of year that creates an inferior mirage. It's evident on the islands when viewed close to the surface, making the islands appear to "stand up" taller due to the mirroring effect of the lower band of the islands. That makes the apparent horizon appear lower than it actually is. So, that could mean that, without a reference object, like a ship or landmass or lighthouse or something out on the sea horizon, I should probably account for some angular "dip" in the apparent horizon due to that inferior mirage, meaning the actual horizon is slightly higher than seen here.

I'll have to calculate what that would be, confirming, of course, that the atmospheric conditions are, in fact, ripe for such a mirage. You just can't tell looking out at a blank horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on June 05, 2018, 06:47:31 PM
Have you tried Mick West's refraction and mirage simulator?

https://www.metabunk.org/simulating-atmospheric-refraction-and-mirages.t7881
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 05, 2018, 07:00:28 PM
Have you tried Mick West's refraction and mirage simulator?

https://www.metabunk.org/simulating-atmospheric-refraction-and-mirages.t7881
I had not.  Thanks for that. Now I'm going to be distracted for the next 30 minutes playing with that.  ;)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 06, 2018, 05:21:13 PM
Rather than wait for Fall conditions when the low horizon visibility is clear enough to see the off shore islands 65 miles away, I propose I use an indicator like the one in the picture (bottom of a ship obscured just beyond point H) to know I've got sufficient viz to record "true" horizon observations.
 
But take a look at that last photo I posted from June 1st.

(http://oi65.tinypic.com/27xfqqb.jpg)

Is that ship at or beyond Flat Earth H distance?  If so, then that must be the "true" horizon (which wasn't at eye-level). If not, then it's lower hull shouldn't be yet merging with a "convergence zone."

If no flaw in this reasoning, I'll proceed and get this done, despite being in the midst of June Gloom season here.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 06, 2018, 09:16:47 PM
(http://www.sacred-texts.com/earth/za/img/fig44.jpg)

This is what S. Rowbotham reported observing from various floors of the Grand Brighton Hotel in his Experiment #15 of Earth Not a Globe.

The Grand sits about 45’ above the shoreline. Observation heights would have likely been 75-150’
(http://oi64.tinypic.com/11bpv84.jpg)
(http://oi66.tinypic.com/2w6hxdz.jpg)

Even if a “dip” in the angle of the horizon from eye level is small, the distance to H is not. Even Rowbotham’s other chapters about perspective and horizon acknowledge that H increases with observer elevation. In globe geometry, that elevation difference extends H about 5 miles. I am not clear how to calculate it in flat earth “natural law of perspective” geometry -- I'm not sure anybody is  (https://forum.tfes.org/index.php?topic=9777.0)-- and now here it appears H is constant despite changes in height.

In his Experiment #15, he refutes this figure:
(http://www.sacred-texts.com/earth/za/img/fig45.jpg)

Yet that is precisely what I have observed so far, even at elevations only up to 100’ from sea level.

Rowbotham makes no mention about the sharpness of the horizon, which can be hazy in Brighton too:

(http://oi67.tinypic.com/20hu7vr.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 06, 2018, 10:51:14 PM
At elevations within the range of Rowbotham's Experiment #15 observations from the Grand Brighton, here's what I saw:

(http://oi66.tinypic.com/33ncge8.jpg)

If I were to observe what Rowbotham describes, with gain in elevation from 10' above the water to 75', I should have seen "the uprising surface ... meet the eye-line"

But it did not. The blue line in the bottom picture would be the new "eye-line"

(http://oi66.tinypic.com/2r3co6e.jpg)

I'm not using a "leveled" clinometer to measure dip here. I'm just observing the horizon using distant islands as an index. But if I gain altitude and I can fix my eye on a spot of land previously hidden that I know is below my level eye-line, then I must be looking across at an angle less than 90 degrees.

The horizon didn't rise to eye-level when I gained elevation.
The distance to the horizon did not remain constant.

I have the advantage here of visible landmarks at or near the horizon that Rowbotham didn't have from Brighton. But even my crude, homemade devices are detecting "dip" at less than 100' above sea level that his clinometer apparently was unable to detect.

Post edit: With the given distances to those islands, the difference between where Rowbotham's predicted "water level rise to eye-line" and the actual horizon is 0.05°. I can attest to the difficulty of measuring such an angular dimension to that degree of granularity. Without the islands for reference, using a clinometer, Rowbotham's error might be understandable since we don't know what kind of instrument he used.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 07, 2018, 06:59:01 AM
From another topic (https://forum.tfes.org/index.php?topic=9883.msg155074#msg155074):

If you cannot produce significant evidence for this wild claim, other than fallacious appeals, then you will need to stop making it.

We do generally admit the limits of our knowledge. However, you guys consistently state "this is known" and "the data is consistent" and similar statements. If you are going to make such claims of something being known, then you are expected to demonstrate your claims.

If you cannot demonstrate your claims, that is an automatic lose.

Agreed.

Rather than citing a drawing handbook, an anecdote where it "appears" or "seems" to be true, and a simulated perspective in video games, I challenge anyone to demonstrate the "horizon always at eye level (https://wiki.tfes.org/Horizon_always_at_Eye_Level)" claim.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on June 07, 2018, 07:16:54 AM
From another topic (https://forum.tfes.org/index.php?topic=9883.msg155074#msg155074):

If you cannot produce significant evidence for this wild claim, other than fallacious appeals, then you will need to stop making it.

We do generally admit the limits of our knowledge. However, you guys consistently state "this is known" and "the data is consistent" and similar statements. If you are going to make such claims of something being known, then you are expected to demonstrate your claims.

If you cannot demonstrate your claims, that is an automatic lose.

Agreed.

Rather than citing a drawing handbook, an anecdote where it "appears" or "seems" to be true, and a simulated perspective in video games, I challenge anyone to demonstrate the "horizon always at eye level (https://wiki.tfes.org/Horizon_always_at_Eye_Level)" claim.

That Wiki page is comically bad. There's not a single demonstration, measurement, photograph, or diagram on it.

Is that really the best they've got? That the horizon "looks like it's at eye level to some people"? One man's musing from 1857? An 'experiment' involving a computer game?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 07, 2018, 08:10:08 AM
Noticed something while reviewing photographs:

(http://oi68.tinypic.com/29fv3at.jpg)

There's a fairway buoy out there I hadn't noticed.

(http://oi65.tinypic.com/15z37yp.jpg)

It's tethered about 3.25 miles from my sealevel, 100' and 400' viewing points, and which means it should sit just a little bit in front of the (globe earth) horizon when viewing from close to sea level. It looks like it's about 35' tall (based on the size of the harbor seals basking on its base) though maybe Tontogary can advise.

(http://oi63.tinypic.com/29cmluo.jpg)

This is serendipitous and lends itself to being yet another advantage for using this sight line to perform and record horizon observations to assess the "eye level" claim.

From 100' vantage point:
(http://oi65.tinypic.com/2lwsyh0.jpg)

From 400' vantage point:
(http://oi68.tinypic.com/eh0or8.jpg)

I'm anticipating clear enough skies and horizons tomorrow to accomplish this test. And if I can time it with some shipping traffic at or near calculated horizon lines, that'll be a bonus.
Title: Re: The Horizon is Always at Eye Level
Post by: Tontogary on June 07, 2018, 11:20:13 AM
Sorry i cannot help Bobby. I have looked through the different charts, and the height is not mentioned, although i can confirm you have the right buoy by looking at it, and the characteristics are the one charted.

I also looked through the coast pilot books, and the List of lights, which were able to give me a fair amount of detail except the height of the light and the total structure.

From experience I wouldn’t say it is more than about 25 feet tall having been past many of these, and comparing them to our freeboard, but i dont think the height is of any great concern, as i dont think you were trying to measure anything.

Sorry.  :(
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 07, 2018, 09:33:38 PM
That's alright. Thanks anyway.

I'm anticipating clear enough skies and horizons tomorrow to accomplish this test. And if I can time it with some shipping traffic at or near calculated horizon lines, that'll be a bonus.

And this just isn't going to happen. I can't see marine traffic 20 miles off the coast due to the haze, even though the sky overhead is crystal blue. The Coronados are in the mist, and conditions are just not prime for performing this "experiment."

So, I'm going to table this for a few months and wait for more Fall-like weather. If I'm not over the subject by then, I'll check back in. But I don't think there's anything more to add to the subject until then.

Out.
Title: Re: The Horizon is Always at Eye Level
Post by: iamcpc on June 15, 2018, 07:07:16 PM
That's alright. Thanks anyway.

I'm anticipating clear enough skies and horizons tomorrow to accomplish this test. And if I can time it with some shipping traffic at or near calculated horizon lines, that'll be a bonus.

And this just isn't going to happen. I can't see marine traffic 20 miles off the coast due to the haze, even though the sky overhead is crystal blue. The Coronados are in the mist, and conditions are just not prime for performing this "experiment."

So, I'm going to table this for a few months and wait for more Fall-like weather. If I'm not over the subject by then, I'll check back in. But I don't think there's anything more to add to the subject until then.

Out.

Have you tried with a telescope by chance?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on June 15, 2018, 07:57:49 PM
I don't have one anymore, so no. I don't think that will resolve the issue of atmospheric clouding.

I have a sense that the "horizon at eye-level" claim may be diminishing in its certainty and centrality to flat earth reasoning.  In fact, the EA discussion has revealed that if it is to be an explanation for observed phenomenon on a flat earth, the horizon can't always be at eye-level but would also drop with elevation.

I'll still collect and post observations after conditions here are right. I may even post a video.

Something I've become acutely aware of those is the uncertainty of correctly sighting the horizon when there are strong inversion layer or ducting effects. I have yet to see a day yet when there hasn't been a significant inferior mirage. If you're just looking at a sea/sky horizon, you wouldn't know there was a mirage. A feature like an island or a lighthouse or a ship at sea (or the sun) reveals the mirage. And then, you have to figure out where above that apparent horizon the real horizon is. 

Since the goal of this wasn't to measure "dip" of the horizon but to detect if there is "dip" or not. My takeaway so far is that at least above 100' elevation, any dip will be enough to exceed the mirage effect that presents an appearance of a lower horizon. But I think this needs to be more clearly understood by both flat and round earth defenders out there with their P900s and producing supporting and debunking videos. I haven't really seen any address the mirage and what it means when assessing whether or not earth's curvature is what's obscuring things at a distance.

Anyway, no. I've not used anything more magnifying than my DLSR's pedestrian zoom.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on September 01, 2018, 10:01:00 PM
Been awhile since I've addressed this topic. Haven't forgotten, but still waiting for the off shore marine layer haze to take its fall/winter vacation and afford me 50+ mile clear SoCal horizon views for performing the final horizon level sightings.

In the meantime, saw this in the JTolen Media 1 video (https://www.youtube.com/watch?v=7-pXWRn_wfk) we've been discussing in the Sphere/Flat "challenge" discussion topic (https://forum.tfes.org/index.php?topic=10486.0).

In the intro section of that IR imagery of San Jacinto, JT references using a theodolite app from an aircraft flight from Buffalo to Chicago, and noting that he saw the water of Lake Erie above where the globe earth horizon line should be (-3.4° from level sight at 37,000').

(http://oi65.tinypic.com/x0wux0.jpg)

I had glossed over most of that background stuff since there wasn't much detail to analyze. But Tom Bishop challenged me to address the Salton Sea sighting JT took seen around the 2:15 mark of that video. Since then, I've looked more closely at the other examples of observations he made where he believes the earth is appearing to be flat vice globe.

As with the San Jacinto case, I don't believe JT's image from the aircraft is supporting the argument he believes it does. But before I dive into my analysis of that theodolite-app annotated image, I'd like to invite Tom to take a closer look. Particularly given the critiques he has made in this topic of my attempts at sighting on the horizon, is JT's example here supportive of a flat earth or of a debunking of the globe?

(I only address this to Tom since he's sometimes willing to come forward on these. Of course, the invitation is open to anyone and not just Tom.)

Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on September 02, 2018, 04:45:40 AM
I don't get this. His image says "we should not see the ground at an angle of -3.3 degrees if the Earth is a sphere" when that's (about) exactly what we should see. And if the Earth was flat, his theodolite should be reading just below 0 degrees.

If he's calibrated correctly, everything he's done points to the horizon being substantially below eye level and to a spherical Earth.

Is he pulling legs? Parodying flat earthers?
Title: Re: The Horizon is Always at Eye Level
Post by: HorstFue on September 02, 2018, 12:54:38 PM
I don't get this. His image says "we should not see the ground at an angle of -3.3 degrees if the Earth is a sphere" when that's (about) exactly what we should see. And if the Earth was flat, his theodolite should be reading just below 0 degrees.
Form  the video: "I placed the cross-hairs down to -3.3°, which is where the horizon should be."  (on a globe earth).
But the cross-hairs point lower than the horizon.

If he's calibrated correctly, everything he's done points to the horizon being substantially below eye level and to a spherical Earth.
That's the point: Calibration of the inclinometer.
How can you calibrate a level instrument on a moving aircraft, a car, a ship? Never!
What you measure is not the "vertical" defined by gravity. Every craft, while moving, experiences additional forces and so accelerations. It could accelerate or break. It could follow a curved path - what I assume is the case in the video. A curved path will create a centrifugal force, which will result in an additional acceleration perpendicular to the gravity vector. Gravity and centrifugal force combined will give a new "local fake vertical", which is not parallel to the real "vertical".

I did not fly an aircraft so far, but many times sailed yachts, A sail yacht, a boat will never go "straight" by itself. All the time you have to correct the course, turning the steering wheel small angles left or right any few seconds, even on dead plane water with no waves and no wind. The resulting course  is not a straight line, but a sequence of flat curves.
I think, same applies to an aircraft. These flat curves generate centrifugal forces, making any level measurement void.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on September 02, 2018, 04:17:52 PM
I don't get this. His image says "we should not see the ground at an angle of -3.3 degrees if the Earth is a sphere" when that's (about) exactly what we should see. And if the Earth was flat, his theodolite should be reading just below 0 degrees.
Form  the video: "I placed the cross-hairs down to -3.3°, which is where the horizon should be."  (on a globe earth).
But the cross-hairs point lower than the horizon.

I get what he's trying to do. He's not sighting the crosshairs on anything. He's just tilted down until he got the 3.3-3.4° "dip" angle that would be the calculated angle between a horizontal line and the line tangent to the earth, coincident with the horizon, from about 37,000'. That's correct.

The crosshairs guides on the screen are static. As the phone tilts, the scale on the right scrolls to display the amount of tilt away from horizontal. So (if calibrated and if accurate) the crosshairs when the gauge is reading 3.3° would be on the globe horizon line from 37,000'.

In the image, he's seeing Lake Erie above the horizon (cross hairs).

Isn't he?

Calibration is certainly an issue. So is precision with these apps. I have Theodolite on my phone, and back in this thread you can find examples of me trying to use it. But I was trying to detect "dip" of around the granular limit of the app's scaling (+/- 0.1°) and found it very difficult, even with a tripod, to measure to that degree of precision.

Not to mention that constant calibration and accuracy of the accelerometers of the phone. It quickly became novelty tool for what I wanted it for. From an airplane in flight, I don't see how you could trust the dip angle measurement down to the tenth of a degree. It's possible he took video and just captured a frame in which he had the dip close, but that still doesn't ensure accuracy of the reading.

However, 3.3 or 3.4° I suppose is close. His point can be made even if the calibration is off a couple tenths of a degree since he's at an elevation where whole degrees matter more than tenths.

What I hope to draw focus on isn't the accuracy of the tool, but his interpretation of what he's seeing. I guarantee you if I had been on a flight, sighted a horizon, put the crosshairs on it and it read out -3.4° and posted it on this board as evidence that the horizon dips and the earth is curved, Tom (at least) would be all over it. As I've said before, I invite the critiques. It's good to be challenged. But critique should be balanced. The same degree of inspection and critique should be made for any argument or evidence presented for either side of the flat/globe debate. What I was hoping from Tom was a recognition that JT's slide from that video may not be supportive of what he's claiming.

Tom is not unique. We all tend to latch onto, without skepticism, evidence claims that support what we believe. And we'll put a magnifying glass to those that contradict what we think we know. If you're only interested in "winning" a debate or strengthening an affirmed tenet, then that makes sense. But if you're are being honest about wanting to get at the truth, then that's misguided approach. You have to be as skeptical of evidence for either side and as rigorous in evaluating it.

I received a lot of critique (some constructive) on my attempts to detect (not measure) horizon dip. I would expect a truth seeker to apply that same degree of rigorous questioning of evidence presented to claim the horizon is at eye level. 
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on October 09, 2018, 10:40:39 PM
Ditching the wire cube. Made sense to me, but too hard to explain and too unwieldy to tote about and set up. (Also, it drew crowds and made me face a lot of questions I'd rather not have to answer.)

On a lark this past weekend, I cobbled this together from some surplus irrigation parts (12" long 1/2" threaded PVC pipe and two barbed elbows). Bought a 10' length (only need about a foot or two) of 1/2" ID vinyl tubing and, voila: a portable water level sighting tool. Found a way to clamp it onto a travel tripod, and with a little water and food coloring....

(http://oi66.tinypic.com/34nr19z.jpg)
(http://oi63.tinypic.com/35aroew.jpg)



Check of the horizon from 90' from here (https://goo.gl/maps/naQwE5VBMKy):

(http://oi65.tinypic.com/rli4cm.jpg)
(http://oi65.tinypic.com/2m4d4ip.jpg)


and from 360' from here (https://goo.gl/maps/rsAzMxhje542):

(http://oi68.tinypic.com/vnnviq.jpg)


I like it.
Title: Re: The Horizon is Always at Eye Level
Post by: RonJ on October 10, 2018, 04:27:34 AM
Checkout the theory of operation of the sextant.  You will find there that there is a height of eye correction needed in your measurement.  On the last ship I was on I think the height of eye was about 130 feet.  That meant if you were standing on a bridge wing taking a sighting with your sextant you had to compensate the measured angle with the height of eye.  If you were to be on a small sailboat taking a measurement at the identical time as someone else on a large ship you would get a slightly smaller measured angle because you are closer to the level of the horizon on a small sailboat.  What you are actually measuring is just the angle of the navigation body above the horizon and a very specific time.  You need the time very accurately because the earth rotates under the star.  When you have an angle from your sextant and your time to the second you can enter the navigation charts (ephemeris) with this data and determine the zenith point of the body that you just measured.  The zenith point is that point on the earth that is directly below the body.  Once you have that position you can make a mark on your chart and draw a circle with a radius determined by the measured angle.  Now after all that work all you have is a line of position.  Your ship's position should be somewhere on that line.  To get your actual position you will need to repeat the same procedure on another star, planet, or the moon.  After you plot the second body you will have your position where the two lines cross.  You could also 'shoot' the sun and determine it's highest point in the sky by measuring it at local apparent noon.  This will give you some information about your position as well.  Few people do this aboard ship these days except for the maritime academy cadets who need to learn celestial navigation as part of their training.  GPS is the primary means of navigation, but using a sextant can teach you a whole lot about the Sun, moon and stars and they way they behave.  This all assumes that the earth is a sphere. Finally, the Horizon is not at eye level.  On any practical measurements the angle difference is very small but if you don't compensate for your height of eye above the horizon your determined position could be off by several miles.  That's no problem unless you are trying to avoid that spot where the rocks are only a few feet underwater.   
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on October 10, 2018, 10:38:52 AM
Ditching the wire cube. Made sense to me, but too hard to explain and too unwieldy to tote about and set up. (Also, it drew crowds and made me face a lot of questions I'd rather not have to answer.)

On a lark this past weekend, I cobbled this together from some surplus irrigation parts (12" long 1/2" threaded PVC pipe and two barbed elbows). Bought a 10' length (only need about a foot or two) of 1/2" ID vinyl tubing and, voila: a portable water level sighting tool. Found a way to clamp it onto a travel tripod, and with a little water and food coloring....

(http://oi66.tinypic.com/34nr19z.jpg)
(http://oi63.tinypic.com/35aroew.jpg)



Check of the horizon from 90' from here (https://goo.gl/maps/naQwE5VBMKy):

(http://oi65.tinypic.com/rli4cm.jpg)
(http://oi65.tinypic.com/2m4d4ip.jpg)


and from 360' from here (https://goo.gl/maps/rsAzMxhje542):

(http://oi68.tinypic.com/vnnviq.jpg)


I like it.
Outstanding work, as always.
I'm sure in the light of this the Horizon Always At Eye Level page will be amended and FE Theory will be moved on immeasurably.
Title: Re: The Horizon is Always at Eye Level
Post by: iamcpc on October 11, 2018, 07:13:17 PM
Outstanding work, as always.
I'm sure in the light of this the Horizon Always At Eye Level page will be amended and FE Theory will be moved on immeasurably.

No way. This is not the first person to have demonstrated observations that suggest that the horizon MIGHT not ALWAYS be at eye level.

I don't have a link to the post but someone can just push this away as optics. The horizon is at eye level it just that the optics don't reflect it.

https://www.metabunk.org/how-to-show-the-horizon-is-below-eye-level-using-actual-eyes.t8845/


I have never heard anyone who believes that the horizon always rises to eye level look at the observations made and say something like 99% of the time the horizon rises to eye level. Nope. Based on these observation I've never seen anyone even concede 1%.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on October 12, 2018, 06:34:00 AM
I have never heard anyone who says they believe that the horizon is always at eye level post a photo with some actual measurements in it: usually they just figure 'cos it's in the middle of the frame, that means it's at eye level. Then they don't understand when you tell them it doesn't work like that.

This is Flat Earth 101. If they don't understand the basics, how are they going to understand more complex things?
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on October 12, 2018, 10:13:15 AM
I have never heard anyone who says they believe that the horizon is always at eye level post a photo with some actual measurements in it: usually they just figure 'cos it's in the middle of the frame, that means it's at eye level. Then they don't understand when you tell them it doesn't work like that.

This is Flat Earth 101. If they don't understand the basics, how are they going to understand more complex things?
I think this is part of their over-reliance of the senses.
The horizon looks about eye level even at altitude, ergo they conclude that it is at eye level.
Many attempts have been made to explain that there are things that we can't perceive but that we can measure - and this is one of them.
It doesn't seem to have made much impact though.

Obviously I was kidding above, no ground will be conceded here, no experiments will be done, no observations made.
This is where Tom's lament about lack of a research budget for FE falls flat, this is something which could be done quickly and cheaply - as Bobby has demonstrated - and the result would move FE Theory on. But they claim they're too busy so nothing moves forward which is why the same discussions go round and round.
Title: Re: The Horizon is Always at Eye Level
Post by: edby on October 12, 2018, 04:23:42 PM
I have never heard anyone who says they believe that the horizon is always at eye level post a photo with some actual measurements in it: usually they just figure 'cos it's in the middle of the frame, that means it's at eye level. Then they don't understand when you tell them it doesn't work like that.

This is Flat Earth 101. If they don't understand the basics, how are they going to understand more complex things?
Bobby’s experiment with the water level sighting tool is excellent as usual. But the problem as usual is the chain of inference required to address ‘Horizon is Always at Eye Level’. The inference is something like this:

1. We can draw an imaginary straight line between the two menisci in the two tubes. [Problem: is an imaginary line a real line, is Euclidean geometry true, what is a ‘meniscus’]

2. This line must be parallel to the surface of the (purportedly flat) earth. [Problem: this follows from the FE claim that water ‘finds its own level’ – whatever that means]

3. If we place our eye so that it is on the ‘line of sight’ connecting the two menisci, then anything on that line must be parallel to surface of [flat] earth [Problem: what exactly is a ‘line of sight’]

4. A straight line drawn in the surface of the earth parallel to the imaginary line will, by the laws of perspective, appear to converge with that imaginary line when it reaches the horizon [Problem: what exactly are ‘laws of perspective’? Are there FE laws different from RE laws.]

For each step there is the problem of explaining the terms, and there are four steps in the chain. My estimate that any FE discussion requiring more then two steps will fail. The other side will stop responding at some point, without any conclusion reached.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on October 12, 2018, 11:33:05 PM
Bobby’s experiment with the water level sighting tool is excellent as usual. But the problem as usual is the chain of inference required to address ‘Horizon is Always at Eye Level’. The inference is something like this:

1. We can draw an imaginary straight line between the two menisci in the two tubes. [Problem: is an imaginary line a real line, is Euclidean geometry true, what is a ‘meniscus’]

2. This line must be parallel to the surface of the (purportedly flat) earth. [Problem: this follows from the FE claim that water ‘finds its own level’ – whatever that means]

3. If we place our eye so that it is on the ‘line of sight’ connecting the two menisci, then anything on that line must be parallel to surface of [flat] earth [Problem: what exactly is a ‘line of sight’]

4. A straight line drawn in the surface of the earth parallel to the imaginary line will, by the laws of perspective, appear to converge with that imaginary line when it reaches the horizon [Problem: what exactly are ‘laws of perspective’? Are there FE laws different from RE laws.]

For each step there is the problem of explaining the terms, and there are four steps in the chain. My estimate that any FE discussion requiring more then two steps will fail. The other side will stop responding at some point, without any conclusion reached.

This experiment is about as zetetic as it can get. It doesn't require expensive equipment. Anyone can do it. And the possible outcomes are bifurcated and agreed upon: if the horizon is always at eye level, the surface is flat. If the horizon dips, the surface is convex.

Though I did anticipate the results would show that the horizon dips and that the earth's surface was convex, I didn't make that prediction nor set out to bias the experiments to favor dippage. When the results were ambiguous, I posted them. When there was uncertainty about whether or not I was seeing the horizon, I admitted that. 

But in the end, I feel that these observations showed that the horizon does, in fact, drop from level sight as elevation increases. It doesn't seem very zetetic to me to, ex post facto, reject the observations for a litany of reasons without offering ways to better perform them. That's like having the bias that is supposedly the problem with the scientific method. The zetetic is not supposed to be looking for a result of flatness and then trying to find reasons why the results are not what one wants or expects.

These homegrown methods aren't attempting to show how much the horizon dips. Only whether it does or doesn't. If the methods I've employed are not adequate, then what would be? I'm game for any suggestions. 

Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on October 13, 2018, 01:19:39 AM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content. I have been thinking of making a page dedicated to the water level experiment as well.

I like to see the results of bobby's experiments and posts. I wouldn't mind putting every one of them somewhere in some kind of repository. I have sent a PM to some of the others about what we can do.
Title: Re: The Horizon is Always at Eye Level
Post by: hollow earther on October 14, 2018, 01:00:11 AM
You will notice that my "well-educated" friend supports NASA, but unconditionally evades questions about anything related to the shape of the Earth or the redundant, blatant moves NASA makes to hide the fact that the Earth is not round.








My name is sarcastic, don't roast me!
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on October 14, 2018, 02:35:10 AM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content. I have been thinking of making a page dedicated to the water level experiment as well.

I like to see the results of bobby's experiments and posts. I wouldn't mind putting every one of them somewhere in some kind of repository. I have sent a PM to some of the others about what we can do.

Cool! I did not see that coming.

/thread?
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on October 14, 2018, 06:29:55 AM
I agree that the horizon isn't always at eye level, and drops as elevation increases.

Kudos, Tom. Fair play to you.
Title: Re: The Horizon is Always at Eye Level
Post by: Mysfit on October 14, 2018, 06:45:33 AM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content. I have been thinking of making a page dedicated to the water level experiment as well.

I like to see the results of bobby's experiments and posts. I wouldn't mind putting every one of them somewhere in some kind of repository. I have sent a PM to some of the others about what we can do.
*starts crying*
Go wiki go
Title: Re: The Horizon is Always at Eye Level
Post by: inquisitive on October 14, 2018, 09:46:37 PM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content. I have been thinking of making a page dedicated to the water level experiment as well.

I like to see the results of bobby's experiments and posts. I wouldn't mind putting every one of them somewhere in some kind of repository. I have sent a PM to some of the others about what we can do.
When is it at eye level?
Title: Re: The Horizon is Always at Eye Level
Post by: MiraculumHelix on October 15, 2018, 07:16:12 AM
While the horizon is not always at eye level, we all agree that the higher you go, the farther you can see, because no obstacles block your view, right?
So, basically, if you climb Mount Everest, you will see that it's day all time. Why? Well, obvious, isn't it? You can see the sun at all times, travelling in circles across the plane, only trailed by the moon. And because there is nothing higher than the mount everest, it's light can be seen day in day out. Try it. THere is no thing such as a night on mount everest. The night only occurs because mountains or buildings are blocking the sun.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on October 15, 2018, 07:23:42 AM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content. I have been thinking of making a page dedicated to the water level experiment as well.

I like to see the results of bobby's experiments and posts. I wouldn't mind putting every one of them somewhere in some kind of repository. I have sent a PM to some of the others about what we can do.
When is it at eye level?

When you're standing at about the same level as the horizon - for example, lying on a beach looking out to sea.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on October 15, 2018, 10:08:48 AM
I agree that the horizon isn't always at eye level, and drops as elevation increases.
Wow. That is only the 3rd time I've ever seen you cede any ground in any discussion and the first time it's something which actually contradicts Rowbotham's FE model.
I'm interested what brought about this change of mind, Bobby has shown the result clearly but he did so some time ago and you dismissed it.
Don't get me wrong, I'm delighted you've finally conceded this, this is how progress is made, but I'm curious as to why you've done so now.

So how does this change your model of perspective? Horizon remaining at eye level was a key part of it, no?
Title: Re: The Horizon is Always at Eye Level
Post by: iamcpc on October 26, 2018, 07:53:52 PM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content.

There are a lot of people on here who would strongly disagree with you Tom. Before updating the wiki why don't we first determine if the horizon really drops or if we just perceive the drop of the horizon due to some sort of environment/atmospheric/optical phenomenon
Title: Re: The Horizon is Always at Eye Level
Post by: Tom Bishop on October 26, 2018, 08:48:08 PM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content.

There are a lot of people on here who would strongly disagree with you Tom. Before updating the wiki why don't we first determine if the horizon really drops or if we just perceive the drop of the horizon due to some sort of environment/atmospheric/optical phenomenon

I believe that was the point of all of this. The horizon isn't "always at eye level" as asserted in the Wiki, and a change is needed. The Wiki forgot about the concept of fog and atmosphere.

Bobby posted some images of the horizon level changing based on changing atmospheric conditions. I think that this is a fair change, and I do think that most FE'ers use the atmosphere argument when this subject comes up. You were misinterpreting the meaning of my post. It agrees with you.
Title: Re: The Horizon is Always at Eye Level
Post by: iamcpc on October 26, 2018, 08:58:22 PM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content.

There are a lot of people on here who would strongly disagree with you Tom. Before updating the wiki why don't we first determine if the horizon really drops or if we just perceive the drop of the horizon due to some sort of environment/atmospheric/optical phenomenon

I believe that was the point of all of this. The horizon isn't "always at eye level" as asserted in the Wiki, and a change is needed. The Wiki forgot about the concept of fog and atmosphere.

Bobby posted some images of the horizon level changing based on changing atmospheric conditions. I think that this is a fair change, and I do think that most FE'ers use the atmosphere argument when this subject comes up. You were misinterpreting the meaning of my post.

The question I have is that does the horizon drop or does the horizon stay at the same level and our optical devices just perceive a change in the level of the horizon do to environmental/optical conditions?


If perceived horizon is affected by altitude what methods could we use to determine why this is?

In flat earth models in which the earth has an edge or a defined end wouldn't the edge of the earth be considered a horizon?

If this is the case and you went to a high enough altitude wouldn't the perceived horizon (assuming there was no optical/environmental phenomenon) also drop in these flat earth models too?



Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on October 26, 2018, 09:30:27 PM
I agree that the horizon isn't always at eye level, and drops as elevation increases. I have actually been planning to update the Wiki with some of Bobby's content.

There are a lot of people on here who would strongly disagree with you Tom. Before updating the wiki why don't we first determine if the horizon really drops or if we just perceive the drop of the horizon due to some sort of environment/atmospheric/optical phenomenon

I believe that was the point of all of this. The horizon isn't "always at eye level" as asserted in the Wiki, and a change is needed. The Wiki forgot about the concept of fog and atmosphere.

Bobby posted some images of the horizon level changing based on changing atmospheric conditions. I think that this is a fair change, and I do think that most FE'ers use the atmosphere argument when this subject comes up. You were misinterpreting the meaning of my post. It agrees with you.
Ah, I knew there had to be a qualifier.

Yes, locating the horizon is affected by atmospheric conditions. Fog and haze can obscure the horizon, and if it's in the distance, it can present appearance of a false horizon.

Also, conditions that cause an inferior mirage can create a very convincing appearance of a horizon when, in fact, the true horizon is actually higher; but due to the mirage, an inverted image of sky obscures the actual horizon.

Both of these can fool you into thinking the line of the horizon is lower than it actually is. With mirage, you can 'defeat' that with elevation if the layer of atmosphere causing the optics is shallow enough.

But those are specific deviations. When the atmosphere is clear and mirage conditions are minimal or non-existent, the horizon still fails to rise to eye-level with increasing elevation.

Even in looming conditions when atmospheric refraction can be extreme (and by this I don't mean mirage but simply greater refractive index than standard which causes the earth to appear to have less of a curve), the horizon dips with elevation. It would require a refractive index causing light to match the curvature of the earth for the earth to appear flat and the horizon remain at eye level.

No. The horizon does not rise with eye level. It would IF the earth was flat, but since it does not, the earth can't be flat. Failure of the horizon to match eye level doesn't mean the earth is a globe, but it can't be flat. It also means EnaG's explanation of perspective is in error. That's just a zetetic conclusion.

Note: I've been observing and photographing the Mexican Coronado Islands from San Diego's Point Loma for months. From vantage points 360-410 feet above sea level, the horizon line has never risen above this outcrop spur on Middle Coronado. The line of an apparent horizon will sometimes appear to be lower when there is fog behind the island or when inferior mirage creates a mirror-fold. And sometimes you can't see that spur at all when the fog or haze is close in.  But never does a horizon line appear above that level, which is far lower than the 400' eye level.  That's the limit of how high the horizon rises, and it's consistent what a globe earth calculator claims when standard atmospheric refraction is factored:

(http://oi65.tinypic.com/32zj495.jpg)

I'd also like to point out that I've been hawking a Webcam streaming from Pacific Beach, and have noted that while sometimes the horizon is indistinct or uncertain, it is never seen above this line on a reference palm street.

(http://oi67.tinypic.com/110x6w1.jpg)

So, if you're going to use my results or my images, make sure you don't misrepresent them to say that it is atmospheric conditions that cause the horizon to appear lower than eye level. Rowbotham was wrong. The wiki is wrong. The horizon dips.
Title: Re: The Horizon is Always at Eye Level
Post by: iamcpc on October 26, 2018, 10:20:39 PM
Yes, locating the horizon is affected by atmospheric conditions. Fog and haze can obscure the horizon, and if it's in the distance, it can present appearance of a false horizon.

I suggest taking pictures at the same time of the same object on the same day at the exact same second (maybe have a buddy on the phone and say 3-2-1-snap) to take a picture. This will eliminate ANY claims about environmental/atmospheric conditions because both images would have been taken under virtually the EXACT same atmospheric and optical conditions.

Then it just strengthens then claim that altitude above sea level, in addition to atmospheric/environmental conditions, affect the perceived horizon. Then the wiki should be updated to show that there are multiple factors which affect the perceived horizon.



No. The horizon does not rise with eye level. It would IF the earth was flat, but since it does not, the earth can't be flat. Failure of the horizon to match eye level doesn't mean the earth is a globe, but it can't be flat. It also means EnaG's explanation of perspective is in error. That's just a zetetic conclusion.

This would only be correct if you were talking about an infinite single flat plane flat earth model. Most of the flat earth models involve some sort of end/edge of the earth. Even in these models if you went up high enough you would just be looking down at the earth and the horizon along with it. The end/edge of the earth in these models would be considered the horizon.
Title: Re: The Horizon is Always at Eye Level
Post by: edby on October 27, 2018, 07:54:41 AM
I suggest taking pictures at the same time of the same object on the same day at the exact same second (maybe have a buddy on the phone and say 3-2-1-snap) to take a picture. This will eliminate ANY claims about environmental/atmospheric conditions because both images would have been taken under virtually the EXACT same atmospheric and optical conditions.
I was about to suggest the same thing.

In addition, to see whether this distortion effect is due to random multiple causes, or a single cause (i) take pictures at different days at sea level, to test whether the effect operates at sea level and (ii) the same thing but higher up, at exactly the same location.

If the random hypothesis is correct, you will see a scatter graph as the 'perceived horizon' moves up and down. If there is a single cause, you will get measurements close to each other.

If a single cause, then the question is whether refraction consistently operates on a flat earth in a way entirely consistent with earth being curved, or whether earth actually is curved.
Title: Re: The Horizon is Always at Eye Level
Post by: zorbakim on October 29, 2018, 09:03:52 AM
Annotated:

(http://oi66.tinypic.com/24whidj.jpg)

(http://oi66.tinypic.com/xfck06.jpg)

interesting. But It is hard to understand that the island is below the eye level.
In addition, The extension lines are not correct.
The device may not be accurate.
When I try again, they don't meet at one point.
Some meet a little above the horizon.
(I don't know how to insert a picture.)
Precision is important in this experiment.
The result varies from a slight angle.
I've done it three times,
The points of intersection of the <left extension lines> are usually <below>,
The points of intersection of the <right extension lines> are usually <above>.

If the island higher than an observer is below eye level,
it is impossible on FE.
But I don't think that's possible.
When I draw the line, eye level is lower than yours.

By the way, How far is it to the island?
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on October 29, 2018, 03:52:02 PM
I've abandoned the wire cube for precisely the confusion is causes some people. The device was never supposed to be a precision instrument, but just to show how lines of perspective can contribute to identifying where "eye-level" is. But because of imperfections in the components that are not designed for surveying, some of the wires (or in the assembly itself) would not align. You had to be able to look at the trends. And at low viewing elevations, it was ambiguous. But at higher elevations, the Area of Uncertainty (AOU) of the intersecting lines would be completely above the horizon even if they didn't converge to a dot.

But it was too cumbersome to tote around and set up, had to be leveled and aligned (at least in order to avoid having to explain why that didn't matter) and the smaller imprecision was enough for naysayers (like you) to want to reject what should be obvious. So, I stopped using it.

The target islands are companions to the one I showed before in my video challenging your 1m wave obscuring a 100m building claim. There are a set of 4 islands south of San Diego off the Mexican coast called the Coronado Islands. They were anywhere from 100 ft to about 400 ft high and about 17 or so miles from Point Loma in most of my images.

With coming Santa Ana conditions and low humidity, I'm hoping to have some good visibility, and hope to take a level sighting of the islands from a 360' and 410' vantage point and document one final time, under best possible conditions, whether or not they align according to a flat earth or a convex earth. 

(I have another video about sighting a smokestack in Carlsbad from a sea level spot in La Jolla across 20 miles of open water, and given good visibility, I hope to capture another set of images of that sighting.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on November 04, 2018, 04:48:29 PM
Some evidence of horizon uncertainty:

From Friday morning, November 2nd:

https://www.youtube.com/watch?v=vM5-xtihd5E
https://www.youtube.com/watch?v=118ob4AmrtY

The horizon is below eye level but watch it move. It moves up and done, but then so does the smoke stack.

The stack is 400 feet high. The roof of the structure is 140 ft above sea level. The proportion isn't right. Something's happening, optically.

Added a couple of horizontal index lines:
https://www.youtube.com/watch?v=r49yVaoVE8M

I am tending toward believing that a temperature inversion is causing an opacity beyond the distance of the apparent horizon, making that structure below the stack appear stretched and abnormally vertically elongated. But it isn't doing it at where the horizon line is because we can see boats transiting along that line.  But I have to wonder if there isn't something like mirage occurring beyond the distance of those boats that is inverting and inferior miraging (can I make that a verb) the power station building, making it look almost as tall as the smoke stack. I have to wonder what we would see if that "veil" was lifted. Would we see the houses and the bluffs above the beach? Or would the horizon line appear higher?

I'm pretty sure my telescope was rock solid. I was in a protected area and there was little wind anyway. Any motion, both vertically and laterally, has to be due to optics. And that smokestack is definitely moving over the course of 10-20 minutes per sequence. It's not producing a "sinking ship" effect, but it does call into question where the horizon is if trying to determine if it's at eye-level.
Title: Re: The Horizon is Always at Eye Level
Post by: seriousb1tch on November 06, 2018, 01:15:32 AM
Math was never designed to be applied to real-life situations. What is the point of linear approximation? What is the point of life? Nobody can come to a conclusion and thus prove that the Earth is flat. However, it all depends on what you believe in. Yes, the horizon is always eye-level, so yes, I believe the earth is flat. It doesn't matter in any other perspective, only my sole perspective is what counts for me. Ignorance is bliss and I can proud to be an American.
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on November 06, 2018, 09:35:47 AM
However, it all depends on what you believe in.
No, it doesn't.
Whether the horizon remains at eye level as you ascend is not a matter of belief.
It is something which can be clearly determined in a way which can be repeated by anyone.
This is not a matter of opinion.
Title: Re: The Horizon is Always at Eye Level
Post by: Earthman on November 06, 2018, 03:13:28 PM
No, the horizon does not lower on a plane as elevation is increased. It's geometrically impossible on a plane. The line of sight fixed on the horizon will remain the same as elevation is increased, making more of the plane visible. The line of sight to the horizon will never lower or raise on a plane. Anything else is an optical illusion. If at any point the horizon begins to lower, it's no longer a plane but becomes a horizontal tube shape.   

Too much education can distort a mind.

If it any point the horizon begins to lower as elevation increases, then Globies really live on a horizontal tube. Either way, they still lose.

Title: Re: The Horizon is Always at Eye Level
Post by: inquisitive on November 06, 2018, 04:24:46 PM
Math was never designed to be applied to real-life situations. What is the point of linear approximation? What is the point of life? Nobody can come to a conclusion and thus prove that the Earth is flat. However, it all depends on what you believe in. Yes, the horizon is always eye-level, so yes, I believe the earth is flat. It doesn't matter in any other perspective, only my sole perspective is what counts for me. Ignorance is bliss and I can proud to be an American.
What do you mean by 'eye level'?
Title: Re: The Horizon is Always at Eye Level
Post by: Earthman on November 06, 2018, 04:39:47 PM
Define "eye-level".

And also, we've discussed this at length before and the flat earthers didn't understand any of the evidence presented.

Wasn't there an experiment performed a short while ago that soundly disproved this, using a u-tube filled with coloured water?

https://www.youtube.com/watch?v=NqOQ_BCtqUI
Yowza!  That's pretty much what I was thinking about doing.

But I thought I'd invite the community here to talk it through first: what am I measuring. How should I be sure to do it (and document it). And make predictions about the results or analysis of predicted results. Do all that before putting in the effort.

The wiki is making the claim and using that as the basis for a flat earth argument about horizons. I thought it might be worthwhile to test the claim.

This experiment with a water level only proves how to make second horizontal line above another. That's all.

A water level is used to establish a horizontal line.

The ends of two horizontal lines on the same level plane will meet because they are the same height.

An end of a horizontal line above another at any height will never meet the lower horizontal line.

This experiment only proves a second horizontal line is gaining height above another making it appear the lower is dropping as elevation is increased. The lower will always appear even lower as the other gains height.

Title: Re: The Horizon is Always at Eye Level
Post by: edby on November 06, 2018, 05:00:09 PM
This experiment only proves a second horizontal line is gaining height above another making it appear the lower is dropping as elevation is increased. The lower will always appear even lower as the other gains height.
So in your view the hypothesis that the earth is flat is consistent with the horizon not rising to eye level?
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on November 06, 2018, 05:53:29 PM
No, the horizon does not lower on a plane as elevation is increased. It's geometrically impossible on a plane.
No. Well, on an infinite plane maybe.
On a finite plane you can either see the edge of the plane of you can see...as far as you can see.
Either way, you'd still be looking down at the horizon

(https://image.ibb.co/fxUSB7/horizon.jpg)
Title: Re: The Horizon is Always at Eye Level
Post by: Earthman on November 06, 2018, 06:15:18 PM
This experiment only proves a second horizontal line is gaining height above another making it appear the lower is dropping as elevation is increased. The lower will always appear even lower as the other gains height.
So in your view the hypothesis that the earth is flat is consistent with the horizon not rising to eye level?

It rises to 6' below my eye "Level" at any elevation. The measurement is so minute, it's perfectly fine to use the phrase "The horizon rises to eye level"
Title: Re: The Horizon is Always at Eye Level
Post by: Earthman on November 06, 2018, 06:33:52 PM
No, the horizon does not lower on a plane as elevation is increased. It's geometrically impossible on a plane.
No. Well, on an infinite plane maybe.
On a finite plane you can either see the edge of the plane of you can see...as far as you can see.
Either way, you'd still be looking down at the horizon

(https://image.ibb.co/fxUSB7/horizon.jpg)

There is no "Maybe"

Yes, we are looking down at the horizon, but it's so minute it really can't be measured nor does it matter.

If it's an finite plane, then Earth is a horizontal rod or other type of shape, but it damn sure isn't a continuous curve that forms a sphere. Globies lose anyway. We don't lose because we live within the boundary of a plane and within the boundary of where the Sun shines. Anything beyond it is not really a part of our world, therefore does not really matter.
Title: Re: The Horizon is Always at Eye Level
Post by: stack on November 06, 2018, 08:26:05 PM
There is no "Maybe"

Yes, we are looking down at the horizon, but it's so minute it really can't be measured nor does it matter.

It can be measured and I think it matters to FET - It's pretty core to the "laws of perspective" argument used to explain a bunch of stuff.

If it's an finite plane, then Earth is a horizontal rod or other type of shape, but it damn sure isn't a continuous curve that forms a sphere. Globies lose anyway. We don't lose because we live within the boundary of a plane and within the boundary of where the Sun shines. Anything beyond it is not really a part of our world, therefore does not really matter.

I'm not sure this is a win/lose proposition. If the earth is flat and we need to adjust everything to be in accordance with it, then great. Seems like all of humanity should get busy with that work.
Title: Re: The Horizon is Always at Eye Level
Post by: RonJ on November 07, 2018, 05:08:02 AM
I saw a small misquote:  "water always flows downhill".  The correct quote should be:  "water flows toward the center of gravity". 
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on November 07, 2018, 11:19:52 AM
Yes, we are looking down at the horizon, but it's so minute it really can't be measured nor does it matter.
It can be measured, it has been measured and the amount the horizon dips varies by altitude.
That has all been shown very clearly...I think earlier in this thread.
If you dispute those results then feel free to do your own experiment and post the results for review.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on November 07, 2018, 03:26:42 PM
It can be measured, it has been measured and the amount the horizon dips varies by altitude.
That has all been shown very clearly...I think earlier in this thread.
If you dispute those results then feel free to do your own experiment and post the results for review.
My point, and the premise of this thread, was whether or not the horizon "dips" with increased viewing elevation is a feature that would distinguish a flat earth from a convex one.
If the horizon dips below eye level as height increases, that favors convexity.
If it always stays at eye level, that favors flatness.

I don't know how to explain a horizon falling below eye level with increasing elevation on a flat earth, as depicted in this diagram:

(https://image.ibb.co/fxUSB7/horizon.jpg)

We know other factors can influence the appearance of the horizon. A fog bank can obscure the horizon and make it appear to be closer/lower. Inferior mirage can obscure the horizon with an inverted image of the sky and make the horizon appear to be lower than it actually is. Sub-refractive and super-refractive atmospheric conditions can make the angle to the horizon increase or decrease.

But all else being equal -- of there is no change in atmosphere/atmolayer conditions between viewing points, increasing viewing height always makes the horizon drop. That's to be expected on a convex surface. I know of no way to explain that for a flat surface.

 
Title: Re: The Horizon is Always at Eye Level
Post by: AllAroundTheWorld on November 07, 2018, 03:49:04 PM
The only way to explain it on a flat surface is if the Actual Horizon on my diagram stay at the same distance regardless of height.
That way the angle would increase but, without doing the maths, I think it would do so in a different more linear way than on a globe.
And we can observe that the horizon distance increases with altitude so that doesn't match observations in any case.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on November 07, 2018, 04:18:00 PM
The only way to explain it on a flat surface is if the Actual Horizon on my diagram stay at the same distance regardless of height.
But what would produce such a horizon?

The Natural Laws of Perspective claim of flat earth says the horizon is formed by the vanishing line, which stays at eye level.
What you're drawing is not the flat earth claim, and I can think of no reason to impart that claim to the flat earth argument unless you (or they) can come up with a reason for how such a perceived horizon on a flat earth is formed.
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on November 08, 2018, 05:40:47 PM
Does anyone disagree with any of the following?

1. The horizon appears increasingly below eye level the higher we rise in elevation
2. This angle can be measured fairly easily with a variety of instruments
3. The amount the angle increases is consistent with being on a ball of around 7,900 miles in diameter
4. A horizon occurs as a result of curvature
5. There is no mechanism to cause a horizon on a flat plane
6. Even if there was, the actual measured dip of the horizon (or anything) isn't in line with what it should be on a flat plane
7. The measurable dip to the horizon (or another distant object) is an excellent proof of a spherical earth
Title: Re: The Horizon is Always at Eye Level
Post by: George Jetson on November 08, 2018, 06:11:04 PM
Does anyone disagree with any of the following?

1. The horizon appears increasingly below eye level the higher we rise in elevation
2. This angle can be measured fairly easily with a variety of instruments
2. The amount the angle increases is consistent with being on a ball of around 7,900 miles in diameter
Where's the data?  Where are the calculations and what model ar they based on?
Quote
3. A horizon occurs as a result of curvature
4. There is no mechanism to cause a horizon on a flat plane
If the earth were an infinite plane the horizon would easily be explained because of the logical fact that if an observer were standing parallel to an infinite flat surface he would be able to see no higher than eye level. Ignoring refraction, if he could see higher than eye level while looking straight ahead that would imply that the ground was tilted upwards.  If looking straight ahead the ground appeared lower than eye level that would imply the ground was sloped down but according to the premises the earth and the observers eyes are parallel so by deduction, the observer would, looking straight ahead, only be able to see a horizon line at eye level, that horizon line being at some finite distance that is a function of the observer's height.
Quote
5. Even if there was, the actual measured dip of the horizon (or anything) isn't in line with what it should be on a flat plane
The horizon dip at higher altitudes is explained by flat earthers as being caused by refraction caused by the continual increase in intervening atmosphere between the observer and the horizon.  As far as I know nobody has actually calculated the predicted horizon drop caused by refraction vs. the horizon drop caused by curvature.
Quote
6. The measurable dip to the horizon (or another distant object) is an excellent proof of a spherical earth
It could be if the math fits the spherical model better than the flat model.  I used to lean RE but the fact that so many internet RErs use complete red-herring arguments to defend the globe is undeniable like the claim that a horizon is impossible on a flat earth.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on November 08, 2018, 06:26:44 PM
Does anyone disagree with any of the following?

1. The horizon appears increasingly below eye level the higher we rise in elevation
2. This angle can be measured fairly easily with a variety of instruments
2. The amount the angle increases is consistent with being on a ball of around 7,900 miles in diameter
3. A horizon occurs as a result of curvature
4. There is no mechanism to cause a horizon on a flat plane
5. Even if there was, the actual measured dip of the horizon (or anything) isn't in line with what it should be on a flat plane
6. The measurable dip to the horizon (or another distant object) is an excellent proof of a spherical earth

The first #2 is rather ambiguous. I've found it difficult to measure the angle of horizon dip with any sort of precision without a precision instrument (which I don't have access to). Coarse angle measurements -- which is all you need to tell if the angle increases with elevation -- is easy enough with non-precision and home-made leveling instruments.

The second #2 relates to the first one, but with the added caveat that (as I've been gradually learning from my own experimentation) the atmosphere plays a very large role in influencing deviations from what would be consistent with a sphere of a particular diameter. When the atmosphere bends light to more closely follow the curve of the earth, measurements will appear consistent with an earth of greater diameter. And conversely, if refraction is weaker, the atmosphere will bend light less making the curvature of the earth more pronounced, as if the diameter was smaller.

Calculations of curvature that don't account for the affect of an atmosphere layered over a terrestrial sphere will never meet consistency requirements.

I don't think you'll get agreement from flat earth advocates on 3, 4 or 5 but I won't speak for them.

However, the reasons I've seen for why there is a perceived horizon on a flat plane suggest there should be consensus on #6, although I would reword to say that "measurable dip to the horizon (or another distant object) is a distinguishing feature between a concave earth and a flat earth.

Horizon dip doesn't prove spherical-icity, er, spherical-ness...doesn't prove the earth is a globe. Horizon dip would occur on a cylinder earth too. You need dip in all directions from all locations on the surface to conclude a sphere. And phrasing it as a conditional (if this then convex, if that then flat) makes it a more neutral statement rather than an argument for one or the other.

#6, by the way, is the key premise of this topic, started way back when. If there isn't agreement between flat and globe earth proponents on that, then much posted on this topic has been pointless. But if there is a mechanism that could explain the apparent dip in the horizon with increased elevation on a flat earth, I'd love to invite it.

Note: Electromagnetic Accelerator Theory offers an explanation, but it is contradictory to other flat earth arguments so it can't (or shouldn't) be offered in isolation. In my opinion, the EAT-based flat earth model is a substantially different model and not conflated with what I'll call the more orthodox arguments in defense of a flat earth.
Title: Re: The Horizon is Always at Eye Level
Post by: George Jetson on November 08, 2018, 06:47:17 PM


#6, by the way, is the key premise of this topic, started way back when. If there isn't agreement between flat and globe earth proponents on that, then much posted on this topic has been pointless. But if there is a mechanism that could explain the apparent dip in the horizon with increased elevation on a flat earth, I'd love to invite it.


To reiterate from my last post, the standard FE claim is that the higher you go the greater the distance the light must travel from the horizon line to your eye meaning the light has to travel through a greater volume of refraction-causing atmosphere to reach your eye the higher up you go.  It is this supposed effect that FEs claim causes the horizon drop.  It makes a certain amount of sense to me but I don't know if it actually fits the empirical data.
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on November 08, 2018, 07:29:46 PM


#6, by the way, is the key premise of this topic, started way back when. If there isn't agreement between flat and globe earth proponents on that, then much posted on this topic has been pointless. But if there is a mechanism that could explain the apparent dip in the horizon with increased elevation on a flat earth, I'd love to invite it.


To reiterate from my last post, the standard FE claim is that the higher you go the greater the distance the light must travel from the horizon line to your eye meaning the light has to travel through a greater volume of refraction-causing atmosphere to reach your eye the higher up you go.  It is this supposed effect that FEs claim causes the horizon drop.  It makes a certain amount of sense to me but I don't know if it actually fits the empirical data.

A couple things about this.

On a flat earth, you'd have an atmolayer, not an atmosphere. That's not just semantics. In an atmolayer, air density doesn't curve away from the line of sight as it would with an atmosphere. Having to penetrate more atmo- (air) isn't what causes refractive "bending" of light. Extinction due to scattering and absorption yes, but not refraction. Not unless there are reasons for why the density gradient of the air is different at different distances through which that line of sight passes. But as a characteristic of an atmolayer, it's not "refraction-causing" in the way that an atmosphere would be. Standard atmoSPHERE will cause light to bend toward the curve of the underlying sphere. Standard atmoLAYER would not have that feature.

Secondly, claiming horizon dip on a flat earth is due to refraction of an atmolayer due to an angle of viewing from an elevation of rarer air to a lower elevation of denser air relies on a bending of light that is the opposite of how refraction works. If light from a dipped horizon is being refracted as it encounters the less dense air of the viewer, it will be refracted toward the denser medium, back to toward the surface of the earth. This has the visual effect of raising the apparent elevation of the sighted object not lowering it. In this case, the object is the horizon. For the horizon to appear to decline in angle, the light would have to bend UPWARD, away from the surface of the earth. Horizon dip could be explained by EAT (https://wiki.tfes.org/Electromagnetic_Accelerator) because it's claimed mechanism has light bending upward, away from earth's surface. Refraction by the air could do that too, but it is far from typical. You need a density inversion of the atmolayer for refraction to cause upward-bending light and make the horizon appear to "dip."
Title: Re: The Horizon is Always at Eye Level
Post by: RonJ on November 08, 2018, 08:35:46 PM
I am surprised you guys haven't looked at the publications 'The American Practical Navigator' or the 'Nautical Almanac'.  These publications contain a wealth of information regarding what kind of effects the atmosphere has on the measurements of heavenly bodies.  The theory of the sextant would be most interesting as well.  Yes, height of eye and atmospheric refraction are important considerations in these measurements.  You can even buy a sextant for a reasonable price.  I used to have a plastic Davis sextant that was really quite accurate.  My only problem with it was when I was 'shooting the sun'.  Even a small amount of warping due to the sunlight on a hot day would alter the measurements a little when you are trying to measure angles to the second. I never had any accuracy problems when measuring the moon, stars, or planets at night.  If you are land locked, you can even use a pool of water to get your sights.  I can personally attest that it works, but takes some practice.  In WWII the bomber crews used a bubble sextant for their long distance navigation across the Pacific to bomb Japan.  I often have supper with a pilot who did just that.  He said he never got lost, but came close a couple of times and survived the war.  Of course the flat earth community probably doesn't believe much in that kind of technology because it assumes that the earth is a rotating sphere in orbit around the sun.  On the other hand, it is quite difficult to argue with something that works if properly used.  If it didn't then mariners would have been getting lost for 100's of years.  That hasn't been happening so it's safe to assume that their idea of the earth has some validity.
Title: Re: The Horizon is Always at Eye Level
Post by: George Jetson on November 08, 2018, 10:07:10 PM


#6, by the way, is the key premise of this topic, started way back when. If there isn't agreement between flat and globe earth proponents on that, then much posted on this topic has been pointless. But if there is a mechanism that could explain the apparent dip in the horizon with increased elevation on a flat earth, I'd love to invite it.


To reiterate from my last post, the standard FE claim is that the higher you go the greater the distance the light must travel from the horizon line to your eye meaning the light has to travel through a greater volume of refraction-causing atmosphere to reach your eye the higher up you go.  It is this supposed effect that FEs claim causes the horizon drop.  It makes a certain amount of sense to me but I don't know if it actually fits the empirical data.

A couple things about this.

On a flat earth, you'd have an atmolayer, not an atmosphere. That's not just semantics. In an atmolayer, air density doesn't curve away from the line of sight as it would with an atmosphere. Having to penetrate more atmo- (air) isn't what causes refractive "bending" of light. Extinction due to scattering and absorption yes, but not refraction. Not unless there are reasons for why the density gradient of the air is different at different distances through which that line of sight passes. But as a characteristic of an atmolayer, it's not "refraction-causing" in the way that an atmosphere would be. Standard atmoSPHERE will cause light to bend toward the curve of the underlying sphere. Standard atmoLAYER would not have that feature.

Secondly, claiming horizon dip on a flat earth is due to refraction of an atmolayer due to an angle of viewing from an elevation of rarer air to a lower elevation of denser air relies on a bending of light that is the opposite of how refraction works. If light from a dipped horizon is being refracted as it encounters the less dense air of the viewer, it will be refracted toward the denser medium, back to toward the surface of the earth. This has the visual effect of raising the apparent elevation of the sighted object not lowering it. In this case, the object is the horizon. For the horizon to appear to decline in angle, the light would have to bend UPWARD, away from the surface of the earth. Horizon dip could be explained by EAT (https://wiki.tfes.org/Electromagnetic_Accelerator) because it's claimed mechanism has light bending upward, away from earth's surface. Refraction by the air could do that too, but it is far from typical. You need a density inversion of the atmolayer for refraction to cause upward-bending light and make the horizon appear to "dip."
Thanks for the optics lesson.  :)
Title: Re: The Horizon is Always at Eye Level
Post by: Max_Almond on November 12, 2018, 07:45:35 AM
George J -

1. We can calculate horizon dip angles ourselves, or use an online tool, like metabunk.org/curve
2. You seem to be saying that "the distance to the horizon on a flat plane is related to the height of the observer". Can you give predicted horizon distances, then, for an observer at, say, 100 feet, 1000 feet, and 10,000 feet? What is the formula? Can you provide a diagram of how this would work?

Bobby Shafto -

Excellent points, well made. I shall adjust. :)

Quote from: Max_Almond
Does anyone disagree with any of the following?

1. The angle of dip to the horizon is a distinguishing feature between a concave earth and a flat earth
2. Given suitable conditions and location, we are able to see the horizon
3. The angle of dip to the horizon can be measured using a variety of instruments
4. This angle increases the higher we rise in elevation
5. The value of the angle, and the amount the angle increases, is consistent with an observer on a ball of around 7,900 miles in diameter (allowing for a small margin of deviation caused by atmospheric conditions, refraction, etc)
6. The value of the angle, and the amount the angle increases, is inconsistent with an observer on a flat plane, infinite or otherwise, even taking into account variations caused by atmospheric conditions, refraction, etc
7. In any case, there is no mechanism that would cause a horizon on a flat plane, and no formula that predicts what the angle to the horizon should be
8. The measurable angle of the dip to the horizon is an excellent disproof of the flat earth idea
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on November 13, 2018, 11:48:18 PM
This was posted on another topic, but I'd like to reply here where I can ask a question related to this topic:

Distance to the sun is about 6,700km.
I'll show you the video later.
Video is comfortable for me because of the language barrier.

On the other flat earth site, I asked you about how you calculate distance to a horizon and how much of an object beyond that horizon is hidden, either by the horizon or by obscuring objects.

You said you would do a video about that, but I haven't seen it yet.

I have found it very difficult to get an answer on how a horizon is defined and how distance to it is calculated on a flat earth. You've offered some numbers and figures in some of your videos but haven't shown how you derived them. I asked and you said it was complicated and takes experience. But you did finally say you would explain it.

This horizon topic is well-suited for discussing this, so I would ask if you're going to do a video, explain how to calculate horizon distance first. I'm much more eager to hear about that than how the sun can be explained as 6700km away. Maybe they're connected. I don't know.

(I don't visit the other site regularly so maybe you posted it and I missed it. If so, I apologize. I'll check later.)
Title: Re: The Horizon is Always at Eye Level
Post by: Bobby Shafto on December 30, 2018, 02:04:26 PM
I did a short summary of what I found during course of this discussion. Very short.

https://www.youtube.com/watch?v=RUr9ymz_nVI
Title: Re: The Horizon is Always at Eye Level
Post by: iamcpc on January 04, 2019, 06:08:13 PM
I did a short summary of what I found during course of this discussion. Very short.

Bobby,



I saw this video which pretty much corroborates your observations. It's pretty clear that the higher the drone gets the lower the horizon gets.


Same day, same time, same temperature, humidity, same optical conditions, same place:

https://youtu.be/NzY5du8LMgk



Still it can easily be explained that the perceived drop in horizon is nothing more than an optical illusion.

The light maintians it's curvature when the drone descends, causing the land to appear to sink. It wouldn't change over seconds.

The video of light bending over time in that area pretty much discredits any one observation, if not all of them. Considering that timelapse, it must now be shown whether light is bending or not.

The fact that the earth is pretty much the size of Kerbal in Soundly's images isn't too crediting, either.