[Bobby Shafto]

Tom? Perspective is perceptual. The land doesn't physical rise. H values don't physically change.

As the apparent angle of the sun changes, so does the angle of the plane of the bottom of the clouds. Never does the plane of something higher descend below a parallel plane below it. They both appear to descend, but the sun's angle will and can never decrease greater than the plane of the clouds.

What you're depicting isn't even what Rowbotham's describes as the Law of Perspective.

Try it. Set up a model and show me how perspective accomplishes what you describe. It won't work.

I can make it work by "cheating," or by invoking methods other than perspective. But the perspective explanation is sleight of hand. It doesn't work that way.

[Bobby Shafto]

Nice shot Bobby.

Wish I could take credit, but it's by a local photography with a knack/skill for getting some amazing sunrise and sunset shots in San Diego.

[Tom Bishop]

Tom? Perspective is perceptual. The land doesn't physical rise. H values don't physically change.

As the apparent angle of the sun changes, so does the angle of the plane of the bottom of the clouds. Never does the plane of something higher descend below a parallel plane below it. They both appear to descend, but the sun's angle will and can never decrease greater than the plane of the clouds.

What you're depicting isn't even what Rowbotham's describes as the Law of Perspective.

Try it. Set up a model and show me how perspective accomplishes what you describe. It won't work.

I can make it work by "cheating," or by invoking methods other than perspective. But the perspective explanation is sleight of hand. It doesn't work that way.

Consider a rail road track perspective scene. Do you agree that the two metal railroad tracks on the railroad in such a scene appear to get so close together that they eventually become one, for all intents? And, do you agree that those tracks have not really become one?

That is what is happening with perspective; the sun is merging into the earth/atmosphere/etc via perspective.

Euclid imagined that this would not happen for an infinite distance away; but he never really demonstrated his ideas. We do see things merge, as with the railroad example above, at non-infinite distances.

[Spingo]

If you were at the altitude of the reddish areas in the clouds, at that moment, do you think that you would be seeing a reddish sunset at the horizon?

You'd see a reddish sunrise, since I took the picture this morning, but yes.

Then it seems that your question has been answered. Those clouds are seeing a reddish sun at the horizon

Not my point. The clouds are illuminated from the bottom, which means that, if the Earth is flat and the sun is thousands of miles above it, then it must be something other than the sun. The reddish sun at the horizon is the RE explanation.

If those clouds were a mirror, would you see the sun at the horizon?

That's what the clouds are in this case; a mirror. Those clouds a little higher up in altitude are seeing a sun that is higher above the horizon, and which is not sending out as much red light.

Sorry Tom but that is clearly false. The sun is sending out a constant level of light 24/7 it never changes. It is we who change constantly by virtue of our position. The colour is due to red light having a shorter wavelength and less prone to scattering. It has absolutely nothing to do with decreased output from the sun if that’s what you are implying.

[9 out of 10 doctors agree]

Clouds aren't mirrors.

Sure they are. You don't believe that we are seeing reflected light?

We're not seeing reflected light. Do you see the landscape miles away when it's overcast?

Sorry if I'm speaking out of turn, but I'd agree with Tom that clouds illuminated by the sun are reflecting the sun's light. Clouds aren't self-illuminating. The reddish glow on the underside of clouds is reflected light from the sun setting or rising.

"Mirror" might be an exaggeration since we aren't seeing the sun in the clouds, but we are seeing the reflected light from the sun on the clouds.

My question, though, however you want to put is, is how is the sun getting an angle on the "mirror" for its light to be reflected? Perspective doesn't gain the sun that angle.

It's only "reflected" in the sense that moonlight is reflected sunlight. Clouds are colloids, they scatter light.


Tom, riddle me this: if I'm hang-gliding from the center of a cumulus cloud, then it will extend almost to eye level from my POV, and probably below eye level depending on the topography of the bottom. If the horizon extends up to eye level, then how does the sun fit between the horizon and the cloud?

[Spingo]

Tom? Perspective is perceptual. The land doesn't physical rise. H values don't physically change.

As the apparent angle of the sun changes, so does the angle of the plane of the bottom of the clouds. Never does the plane of something higher descend below a parallel plane below it. They both appear to descend, but the sun's angle will and can never decrease greater than the plane of the clouds.

What you're depicting isn't even what Rowbotham's describes as the Law of Perspective.

Try it. Set up a model and show me how perspective accomplishes what you describe. It won't work.

I can make it work by "cheating," or by invoking methods other than perspective. But the perspective explanation is sleight of hand. It doesn't work that way.

Consider a rail road track perspective scene. Do you agree that the rail road tracks in such a scene appear to get so close together that they eventually become one, for all intents? And, do you agree that those tracks have not really become one?

That is what is happening with perspective; the sun is merging into the earth/atmosphere/etc via perspective.

Elucid imagined that this would not happen for an infinite distance away; but he never really demonstrated his ideas.

No... the sun is from the perspective of that viewer looking at the sunset, dipping below the horizon. For someone 2000 miles to the west it’s still high in the sky. Just to reinforce the point, the output of light levels from the sun does not change, as far as we are concerned.

[Tom Bishop]

Lets answer this question: Consider a rail road track perspective scene. Do you agree that the two metal railroad tracks on the railroad in such a scene appear to get so close together that they eventually become one, for all intents? And, do you agree that those tracks have not really become one?

Do you, as Euclid asserts would happen under his model, believe that they have become one to your vision at an infinite distance away?

If you agree that the railroad tracks appears to merge a finite distance away, then it must also be possible for the sun to merge a finite distance away.

From previous conversations on this topic, your next course of action will be to quote this post and bold "appears to" as some sort of "gotcha;" but I'll save you the trouble and answer it now: we have never claimed that the sun really physically sets into the earth.

[9 out of 10 doctors agree]

Lets answer this question: Consider a rail road track perspective scene. Do you agree that the rail road tracks in such a scene appear to get so close together that they eventually become one, for all intents? And, do you agree that those tracks have not really become one?

Do you, as Elucid asserts would happen under his model, believe that they have become one to your vision at an infinite distance away?

If you agree that the railroad tracks merge a finite distance away, then it must also be possible for the sun to merge a finite distance away.

Let's table this for now; I know that arguing against perspective without preparation is a lost cause. You should address my other point, i.e. the hang gliding by cloud one.

[Bobby Shafto]

Lets answer this question: Consider a rail road track perspective scene. Do you agree that the rail road tracks in such a scene appear to get so close together that they eventually become one, for all intents? And, do you agree that those tracks have not really become one?

Do you, as Elucid asserts would happen under his model, believe that they have become one to your vision at an infinite distance away?

If you agree that the railroad tracks appear to merge a finite distance away, then it must also be possible for the sun to merge a finite distance away.

Your next course of action will be to quote this post and bold "appears to" in some sort of "gotcha;" but we never claimed that the sun really set into the earth.

Note that you had to include "to your vision" in the statement attributed to Euclid. (No idea if Euclid ever said that, but the accuracy of that's a distraction. We'll go with it.)

The railroad tracks don't actually merge. They only appear to, "to your vision."  It's a perceptual thing.

Perspective doesn't indicate actual distances or heights or other spatial dimensions are actually changing for the objects increasing in distance away from your point of perspective. The sun, over a flat earth, will still be the same height over the flat earth. Perspective doesn't make it descend. It only appears to descend.

And it does so at a rate inverse to the distance. It's not linear. The further it gets, the less the angle of descent.

Which is why I long ago argued with you that Perspective can't cause the sun to reach a horizon on a flat earth. You don't have enough distance for the sun to achieve away from you for the sun to ever get below a certain angle.

The ceiling represented by the plane base of those clouds also "descends" -- apparently, "to your vision" -- according to perspective. So, unless you have bendy light, the sun can never achieve an angle less than that cloud base without physically getting to an actual height lower than that cloud base plane altitude. Perspective isn't the answer.

Let's table this for now; I know that arguing against perspective without preparation is a lost cause.

Sorry. I should know by now this "debate" about Perspective never resolves. I've tried to explain it many different times and way. It never changes.

[Dr Van Nostrand]

If those clouds were a mirror, would you see the sun at the horizon?

That's what the clouds are in this case; a mirror. Those clouds a little higher up in altitude are seeing a sun that is higher above the horizon, and which is not sending out as much red light.

I can't picture this.

With h2>h1, show me how that can be possible.

h1 and h2 are not constant due to perspective. In that illustration the lands are not ascending as they recede, for example.

The lands ascend in altitude, the sun (or the image of the sun) descends in altitude, and everything meets at a finite distance away, rather than the infinite distance away as imagined in the Continuous Universe model of the Ancient Greeks.

Hey Tom,

I wanted to know if I'm looking at your diagram correctly.

The heavy black line is the surface of the earth right? So you're proposing an optical effect (perspective?) that drops the apparent position of the sun below the altitude of the clouds? If we made the 'earth line' horizontal, your sun would be at a very low altitude. Your diagram also places the sun at the same altitude as the clouds?


BTW: Yes, Bobby has posted some very cool pics on TFES.

[Tom Bishop]

Lets answer this question: Consider a rail road track perspective scene. Do you agree that the rail road tracks in such a scene appear to get so close together that they eventually become one, for all intents? And, do you agree that those tracks have not really become one?

Do you, as Elucid asserts would happen under his model, believe that they have become one to your vision at an infinite distance away?

If you agree that the railroad tracks appear to merge a finite distance away, then it must also be possible for the sun to merge a finite distance away.

Your next course of action will be to quote this post and bold "appears to" in some sort of "gotcha;" but we never claimed that the sun really set into the earth.

Note that you had to include "to your vision" in the statement attributed to Euclid. (No idea if Euclid ever said that, but the accuracy of that's a distraction. We'll go with it.)

The railroad tracks don't actually merge. They only appear to, "to your vision."  It's a perceptual thing.

That's right. And the sun doesn't really crash into the earth. It's a perceptual thing.

Perspective doesn't indicate actual distances or heights or other spatial dimensions are actually changing for the objects increasing in distance away from your point of perspective. The sun, over a flat earth, will still be the same height over the flat earth. Perspective doesn't make it descend. It only appears to descend.

Yes. And again, we never claimed that the sun was actually descending and crashing into the earth...

And it does so at a rate inverse to the distance. It's not linear. The further it gets, the less the angle of descent.

Which is why I long ago argued with you that Perspective can't cause the sun to reach a horizon on a flat earth. You don't have enough distance for the sun to achieve away from you for the sun to ever get below a certain angle.

That is correct if you assume that the perspective lines don't merge until infinity... Yet, you agreed that it is possible to see rail road tracks merge.

Will you believe hypothetical math about infinity, or your own eyes?

If we can't see it, why should we believe that particlar factoid about how perspective lines work with infinities?

[Bobby Shafto]

I'm a sucker.

Where in this red herring refutation of infinites and Greeks is perspective ever accounting for a higher plane descending below a lower plane, perceptual or otherwise?

Use Rowbotham's diagram.

The clouds are at one altitude. The sun is at a higher altitude.

The ground plane appears to rise to a horizon point, H. When is the light path from the sun ever able to achieve an angle to the bottom of the clouds?



The perceptual plane that is the bottom of the clouds doesn't extend horizontally while the ground slopes up and the sun's plane slopes down to meet it. It too, slopes down. And, if you're buying Rowbotham, because it is at a lower elevation, it meets the ground plane well before the sun ever does, at some point at or beyond H (whatever finite value that is, which I can never get you to quantify.)

Let's don't just draw lines. Do an experiment. Position a mirror facing the ground but above your head. Then place a light source somewhere further away but at a height higher than the mirror. Show me how you can make it far enough away so that you can see the light source in the mirror. Perspective will cause the distant light source to appear at an angle lower than your view to the mirror, but that won't place the light source below the level of the mirror. That's what perspective does. It's makes things appear to be smaller, lower, closer together. But it doesn't physically make dimensions or intervals smaller. The light will still (and always) be above the mirror.

I'd do it, but I'm a bit tired of performing these practical demos and having them have zero persuasive power. I invite you to do it and show me how it is possible. Perspective doesn't work the way you are applying it. (It doesn't even work the way Rowbotham describes, but even his rationale doesn't salvage perspective as the explanation for how a sun at a higher altitude illuminates the bottom of clouds at a lower altitude.)

[Tom Bishop]

Bobby, you do have persuasive power. I accept everything you have presented and demonstrated. My objections are only with the logical consequences.

Lets look at your experiment. We can take your preconditioned belief that railroad tracks will appear to meet in the distance and do the following.

Lets take that straight length of railroad track and flip it vertically on its side. We now have one metal railroad track atop another:

|:

The vertical distance between these metal railroad tracks is, say, 3 feet. Again, you have already agreed that they will appear to meet in the distance.

If we have a miniature camera on the bottom rail, looking up at a small horizontal mirror positioned 8 inches above it, which faces the bottom track horizontally; perhaps slightly tilted ever so slightly so that it sees the horizon where the tracks meet; does it not follow that the camera, when looking at the reflection, will record the tracks meeting at the horizon?

If this does follow, then the conclusion we were looking for has been met. The mirror caught sight of something above it.

This is really no different than seeing a plane in the distance appearing to be lower than your kitchen ceiling when you look out your kitchen window in the morning. One might scratch their head in wonder how an airplane could seem lower in altitude than their kitchen ceiling.

[Bobby Shafto]

...perhaps slightly tilted ever so slightly so that it sees the horizon where the tracks meet...

No cheating. Mirror must be parallel. No tilting "so that it sees the horizon."

Do it. You're an empiricist. Not a "stands to reason" rationalist. Make sure your "stands to reason" approach isn't incorporating a flaw, like trying to tilt the mirror so that it "sees the horizon."

[Tom Bishop]

...perhaps slightly tilted ever so slightly so that it sees the horizon where the tracks meet...

No cheating. Mirror must be parallel. No tilting "so that it sees the horizon."

Do it. You're an empiricist. Not a "stands to reason" rationalist. Make sure your "stands to reason" approach isn't incorporating a flaw, like trying to tilt the mirror so that it "sees the horizon."

Since these are facts that we all agree with, then I don't believe that this is an experiment that needs to be conducted. There is no controversy with these assertions. We are putting empirical facts together, not hypothetical facts together. If you do see me claim something hypothetical, let me know.

If you don't tilt the mirror then you won't see the horizon. If the mirror is perfectly horizontal then you will always only see the ground when you look up at it.

Recall that the analogy this comes from was the light reflecting off of the clouds; which can reflect light like mirrors, but are not mirrors positioned perfectly horizontal. The clouds can see the horizon, and can receive its reddish light. Higher clouds will be higher in altitude and will be seeing the sun higher above the horizon where the light isn't as reddish. I don't see where the "needing to be perfectly horizontal" piece comes in.

The same reasoning applies if you have a mirror over your head. If it is facing horizontal it will only show the ground. If it is slightly tilted then it will be possible to see a plane in the distance that is much higher in altitude than the mirror. Should that observation be a shock or a mystery? It is none more shocking than seeing a plane apparently below your kitchen ceiling when looking out your kitchen window.

[Curiosity File]

I'm a sucker.

Where in this red herring refutation of infinites and Greeks is perspective ever accounting for a higher plane descending below a lower plane, perceptual or otherwise?

Use Rowbotham's diagram.

The clouds are at one altitude. The sun is at a higher altitude.

The ground plane appears to rise to a horizon point, H. When is the light path from the sun ever able to achieve an angle to the bottom of the clouds?



The perceptual plane that is the bottom of the clouds doesn't extend horizontally while the ground slopes up and the sun's plane slopes down to meet it. It too, slopes down. And, if you're buying Rowbotham, because it is at a lower elevation, it meets the ground plane well before the sun ever does, at some point at or beyond H (whatever finite value that is, which I can never get you to quantify.)

Let's don't just draw lines. Do an experiment. Position a mirror facing the ground but above your head. Then place a light source somewhere further away but at a height higher than the mirror. Show me how you can make it far enough away so that you can see the light source in the mirror. Perspective will cause the distant light source to appear at an angle lower than your view to the mirror, but that won't place the light source below the level of the mirror. That's what perspective does. It's makes things appear to be smaller, lower, closer together. But it doesn't physically make dimensions or intervals smaller. The light will still (and always) be above the mirror.

I'd do it, but I'm a bit tired of performing these practical demos and having them have zero persuasive power. I invite you to do it and show me how it is possible. Perspective doesn't work the way you are applying it. (It doesn't even work the way Rowbotham describes, but even his rationale doesn't salvage perspective as the explanation for how a sun at a higher altitude illuminates the bottom of clouds at a lower altitude.)

Bobby, try moving the viewer point to the center rather than under the clouds.

Example;
I'm standing on a mountaintop of 5,000 feet in elevation. (point A)
to the east of me 100 miles away clouds are at 15,000 feet (point B)
To the west of me at 50 miles the horizon line is at 4,000 feet in elevation. (point C)
I can no longer see the sun but I can see the bottom of the clouds lite up by the sun.



 

[juner]

San Diego, 40 minutes before sunrise on the morning of November 14th..

According to TimeandDate, the sun was over the South Atlantic off the coast of Brazil.

That's over 6200 miles away from San Diego.
The sun had risen in El Paso, TX. (600 miles to the east)
The sun was just about to rise in Tucson, AZ. (365 miles to the east)

The clouds being illuminated were at an altitude of ~15,000 ft., 50-100 miles SE of San Diego. 

In answer to Tom's question, someone at the altitude and location of the illuminated clouds would have seen the sun, risen above the horizon.

Nice shot Bobby.

Do me a favor and refrain from “me too” posts in the upper fora unless you’re going to contribute to the topic. No warning for now but it is low-content.

Also, it is well-known that Bobby is good at taking photos.

[stack]

...perhaps slightly tilted ever so slightly so that it sees the horizon where the tracks meet...

No cheating. Mirror must be parallel. No tilting "so that it sees the horizon."

Do it. You're an empiricist. Not a "stands to reason" rationalist. Make sure your "stands to reason" approach isn't incorporating a flaw, like trying to tilt the mirror so that it "sees the horizon."

Since these are facts that we all agree with, then I don't believe that this is an experiment that needs to be conducted. There is no controversy with these assertions. We are putting empirical facts together, not hypothetical facts together. If you do see me claim something hypothetical, let me know.

If you don't tilt the mirror then you won't see the horizon. If the mirror is perfectly horizontal then you will always only see the ground when you look up at it.

Recall that the analogy this comes from was the light reflecting off of the clouds; which can reflect light like mirrors, but are not mirrors positioned perfectly horizontal. The clouds can see the horizon, and can receive its reddish light. Higher clouds will be higher in altitude and will be seeing the sun higher above the horizon where the light isn't as reddish. I don't see where the "needing to be perfectly horizontal" piece comes in.

The same reasoning applies if you have a mirror over your head. If it is facing horizontal it will only show the ground. If it is slightly tilted then it will be possible to see a plane in the distance that is much higher in altitude than the mirror. Should that observation be a shock or a mystery? It is none more shocking than seeing a plane apparently below your kitchen ceiling when looking out your kitchen window.

It's not a perspective issue. No matter how far away the light source is, the straight rays emanating from a higher height (in this case, Sun: 3000 miles, Clouds: 15000') will not shine UP to the underside of the lower object.

Case in point, Max's Everest shadow thread - A peak lower than Everest casts a rising shadow on Everest - The only way that can occur is if the light rays are emanating from a light source lower than the lower peak:

https://media.istockphoto.com/videos/mt-everest-at-sunset-video-id539252432

https://forum.tfes.org/index.php?topic=11467.0

[Tom Bishop]

That's an easy one. What would observers spaced 200 feet apart up the side of the mountain see?

First, if that second mountain that casts the shadow did not exist, the bottom observer would see the sun set into the horizon as normally, and each observer at higher altitudes, going up the mountain, would see the sun take a little longer to set.

However, since there is a second mountain in the way of the horizon, the bottom observer will see the sun intersect the mountain first, and the top observers will see the sun intersect the mountain last.

Every spot on the mountain is like an observer. The darkness and lightness is what an observer would see of the sun.

[Curiosity File]

...perhaps slightly tilted ever so slightly so that it sees the horizon where the tracks meet...

No cheating. Mirror must be parallel. No tilting "so that it sees the horizon."

Do it. You're an empiricist. Not a "stands to reason" rationalist. Make sure your "stands to reason" approach isn't incorporating a flaw, like trying to tilt the mirror so that it "sees the horizon."

 
   

Since these are facts that we all agree with, then I don't believe that this is an experiment that needs to be conducted. There is no controversy with these assertions. We are putting empirical facts together, not hypothetical facts together. If you do see me claim something hypothetical that no one agrees with, let me know.

If you don't tilt the mirror then you won't see the horizon. If the mirror is perfectly horizontal then you will always only see the ground when you look up at it.

Recall that the analogy this comes from was the light reflecting off of the clouds; which can reflect light like mirrors, but are not mirrors positioned perfectly horizontal. The clouds can see the horizon. I don't see where the "needing to be perfectly horizontal" piece comes in.

The same reasoning applies if you have a mirror over your head. If it is facing horizontal it will only show the ground. If it is slightly tilted then it will be possible to see a plane in the distance that is much higher in altitude than the mirror. Should that observation be a shock? It is none more shocking than seeing a plane apparently below your kitchen ceiling when looking out your kitchen window.