Offline hexagon

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Re: The Horizon is Always at Eye Level
« Reply #280 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...

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #281 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.



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.)
« Last Edit: May 18, 2018, 04:48:29 PM by Bobby Shafto »

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #282 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.)

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #283 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.
« Last Edit: May 19, 2018, 12:41:37 AM by Bobby Shafto »

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Offline Tom Bishop

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Re: The Horizon is Always at Eye Level
« Reply #284 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:



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.
« Last Edit: May 19, 2018, 12:40:25 AM by Tom Bishop »

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #285 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.)

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Offline AATW

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Re: The Horizon is Always at Eye Level
« Reply #286 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.
Tom: "Claiming incredulity is a pretty bad argument. Calling it "insane" or "ridiculous" is not a good argument at all."

TFES Wiki Occam's Razor page, by Tom: "What's the simplest explanation; that NASA has successfully designed and invented never before seen rocket technologies from scratch which can accelerate 100 tons of matter to an escape velocity of 7 miles per second"

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Offline rabinoz

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Re: The Horizon is Always at Eye Level
« Reply #287 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:

Flight Global 6000 HUD EVS SVS, Wolfie6020
And this gives a bit of explanation:

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!

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #288 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.



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.

Offline jcks

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Re: The Horizon is Always at Eye Level
« Reply #289 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 is no longer valid then?

Offline Tontogary

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Re: The Horizon is Always at Eye Level
« Reply #290 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!

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #291 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."

« Last Edit: May 19, 2018, 06:26:31 PM by Bobby Shafto »

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #292 on: May 19, 2018, 07:56:23 PM »
Perspective only.

Centered vertical and horizontal sighting lines, both fore and aft:



Leveling of cube is essential:



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.



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).



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.
« Last Edit: May 19, 2018, 10:59:55 PM by Bobby Shafto »

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Offline rabinoz

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Re: The Horizon is Always at Eye Level
« Reply #293 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:

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.

So the horizon does not rise to eye-level.

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #294 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.



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.



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.

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Offline rabinoz

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Re: The Horizon is Always at Eye Level
« Reply #295 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.

Offline Tontogary

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Re: The Horizon is Always at Eye Level
« Reply #296 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.....

Also, if you haven't heard of bronies before, that reflects poorly on your understanding of the world that surrounds you. It's practically impossible not to know about them.

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Offline AATW

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Re: The Horizon is Always at Eye Level
« Reply #297 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.
Tom: "Claiming incredulity is a pretty bad argument. Calling it "insane" or "ridiculous" is not a good argument at all."

TFES Wiki Occam's Razor page, by Tom: "What's the simplest explanation; that NASA has successfully designed and invented never before seen rocket technologies from scratch which can accelerate 100 tons of matter to an escape velocity of 7 miles per second"

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #298 on: May 21, 2018, 06:47:35 PM »


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.)

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Offline Bobby Shafto

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Re: The Horizon is Always at Eye Level
« Reply #299 on: May 21, 2018, 09:20:52 PM »
Or how about a simple "infinity pool" sighting tool:



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.)