The Flat Earth Society
Flat Earth Discussion Boards => Flat Earth Investigations => Topic started by: ICanScienceThat on June 22, 2018, 06:03:24 PM
-
Hey ya'll... I'm working on a video that discusses some different ideas about how perspective works, and how we can do simple experiments to figure out which ideas are correct and which are not.
I'd like to ask willing participants to take a photograph and record some measurements from it. I have a little questionnaire to ask what your ideas about perspective were before and after doing the experiment. The video would ideally focus on whether or not people who started off with different ideas about perspective arrive at the same conclusions after testing it for themselves.
You can participate completely anonymously if you want.
I would like to avoid any debate over which ideas are correct and which are not. I would prefer that nobody posts their answers here until everyone has had a chance to do the measurements on their own. The idea is to explore whether doing the empirical investigation on your own is a better way to find the truth (as opposed to reading about it online).
Anyone interested/willing to participate?
Here are some questions for before you take your measurements:
https://docs.google.com/forms/d/e/1FAIpQLSeLXshSjVkWswmdGUlh6YztQOk-woesW0MGXMRl2_U7uH4brg/viewform?usp=sf_link
And here is the description of how to take the measurements:
https://docs.google.com/document/d/1M_Qhcexuac2dsv4OzdbdnNFTY4F6dknQ42UMEpzXnno/edit?usp=sharing
To turn in your answers (without sharing them here right away), just PM me or email me at ICanScienceThat@gmail.com
If you'd like to arrange an alternative way to share your answers, feel free to post here telling me how to get them.
The goal of this experiment is to answer the question, "How far away is the vanishing point?" If you'd like to come up with a different experiment to answer that question, that would be great too! All ideas welcome.
(I had posted this on the other forum, but I have few responses so far. So I'm re-posting here hoping to get a few more.)
-
If this helps, below you can find the explanation for how perspective works, including the "distance of the vanishing point" from a mathematical perspective (ha!)
https://forum.tfes.org/index.php?topic=9513.0
-
If this helps, below you can find the explanation for how perspective works, including the "distance of the vanishing point" from a mathematical perspective (ha!)
https://forum.tfes.org/index.php?topic=9513.0
That's a really great article. I presume you wrote that because you'd noticed a lot of people seem to have some different ideas about it. I was really hoping some people would want to learn the material by testing it themselves empirically.
So far, nopes.
-
I didn't get much interest in the experiment sadly. Here's a video of my own results and the ones I got from Bobby Shafto.
https://youtu.be/n9co3x6Fdbc
Watch it and see if your expectations about perspective match up with experiments.
-
Here is my comment:
It's widely observable that overhead receding bodies move at a more constant pace into the horizon the higher they are. For an example imagine that someone is flying a jet into the distance at an illegal altitude of 300 feet. He seems to zoom by pretty fast when he is flies over your head, only slowing down when he is off in the far distance.
Now consider what happens when a jet flies over your head at 45,000 feet. At that altitude a jet appears to move slowly across the sky, throughout its extent, despite that it is traveling at the same speed as the previous plane. With greater altitude the plane seems to move more consistently across the sky. It does not zoom by overhead, only seeming to slow when in the far distance.
Your demonstration with legos successfully shows the low flying jet example, but it does not go further than that.
We've had this page in our Wiki for many years now: https://wiki.tfes.org/Constant_Speed_of_the_Sun
-
Here is my comment:
It's widely observable that overhead receding bodies move at a more constant pace into the horizon the higher they are. For an example imagine that someone is flying a jet into the distance at an illegal altitude of 300 feet. He seems to zoom by pretty fast when he is flies over your head, only slowing down when he is off in the far distance.
Now consider what happens when a jet flies over your head at 45,000 feet. At that altitude a jet appears to move slowly across the sky, throughout its extent, despite that it is traveling at the same speed as the previous plane. With greater altitude the plane seems to move more consistently across the sky. It does not zoom by overhead, only seeming to slow when in the far distance.
Your demonstration with legos successfully shows the low flying jet example, but it does not go further than that.
We've had this page in our Wiki for many years now: https://wiki.tfes.org/Constant_Speed_of_the_Sun
Actually correct, the rate of change of angular velocity of something higher will be slower than something lower.
It's obvious why from a simple diagram:
(https://image.ibb.co/czrrMd/Perspective.jpg)
I've made a bit of a mess of that but it's pretty clear that the difference in angle of the red lines is much more marked than the blue lines.
BUT, there is still a difference in the blue lines and it's clear that the angular velocity will change no matter the height.
Ergo, that Wiki page is wrong. It claims that at some height there is no change in angular velocity. Not true.
-
It's widely observable that overhead receding bodies move at a more constant pace into the horizon the higher they are.
Who has observed this, and where is their data recorded?
-
BUT, there is still a difference in the blue lines and it's clear that the angular velocity will change no matter the height.
Ergo, that Wiki page is wrong. It claims that at some height there is no change in angular velocity. Not true.
Good illustration. It shows the basic concept pretty clearly.
But you already know what I'm going to say. Where did the Ancient Greeks ever provide evidence for their perspective model?
Lets just agree not to have that conversation again for the 100'th time and agree that the Ancient Greek's Continuous Universe model is full of assumptions which have not been demonstrated.
-
BUT, there is still a difference in the blue lines and it's clear that the angular velocity will change no matter the height.
Ergo, that Wiki page is wrong. It claims that at some height there is no change in angular velocity. Not true.
You already know what I'm going to say. Where did the Ancient Greeks ever provide evidence for their perspective model?
Lets just agree not to have that conversation again for the 100'th time and agree that the Ancient Greek's Continuous Universe model is full of assumptions which have not been demonstrated.
You are the one claiming that geometry somehow randomly breaks down at some distance. Where is your evidence?
Show us your empirical measurements of a high flying plane which maintains a consistent angular velocity.
The conversation will happen again and again until you provide some evidence of your claims.
You don't have any. You're just rationalising to try and explain something to shoehorn observations into your model when they clearly don't fit.
And hilariously in the other thread you are arguing that stars slow down as they approach the horizon.
So which is it?
-
Just go to Dubai, then to the surface of the Burj Khalifa building. Enjoy the sunset, then after it compelted, take a ticket to the very top of the same building then enjoy the sunset again.
It's that simple people. Earth is R, not F.
-
You are the one claiming that geometry somehow randomly breaks down at some distance. Where is your evidence?
No. You need to prove that the infinite perspective theory is right in the first place, and that it needs to be disproved.
You need to provide evidence for your claims.
Where are these hidden pockets of infinity? Can you point them out for us?
The fact that perspective lines converge is evidenced right there in reality. The horizon line isn't an "infinite distance away" and train tracks don't appear to merge at an infinite distance away. The reality of finite perspective is on our side.
There is no evidence whatsoever for this infinity nonsense. None. You need to speculate that it exists, whereas we can see that the lines converge.
-
You are the one claiming that geometry somehow randomly breaks down at some distance. Where is your evidence?
No. You need to prove that the infinite perspective theory is right in the first place, and that it needs to be disproved
So you want me to do an experiment over an infinite distance? I don't know how that would work.
My evidence for my claims is every observation of a receding body.
Now where's the evidence for yours?
The rest of your post is you not understanding the limits of visual acuity, or pretending not to.
-
So you want me to do an experiment over an infinite distance? I don't know how that would work.
My evidence for my claims is every observation of a receding body.
You are claiming hidden pockets of infinity, so you should be prepared to somehow demonstrate it. Converging perspective lines is already demonstrated with observation.
As you are claiming that what we see is an "illusion" the burden is on you to demonstrate your concept.
The fact that there is nothing you can easily point to; no studies, examples, or other types of evidence, shows the weakness of the argument.
-
The fact that perspective lines converge is evidenced right there in reality.
Yes in pictures. Pictures are part of reality too.
The horizon line isn't an "infinite distance away"
Agreed, a finite distance away since the picture is a finite distance away.
.. train tracks don't appear to merge at an infinite distance away.
The lines in the picture that represent the train tracks do converge, yes. What is your point. The train tracks themselves do not converge at all, nor are they infinite. They are part of a finite railway system.
There is no evidence whatsoever for this infinity nonsense. None.
Correct. The lines on the picture actually do converge, on the screen or on the paper. The railway lines that they represent do not converge at all.
Case closed.
-
I'm not going to sit here all day asking you for evidence. You know very well that your argument is weak.
-
I'm not going to sit here all day asking you for evidence. You know very well that your argument is weak.
Evidence that perspective lines in pictures converge? You already provided such a picture in another post.
Let's take my first claim. I said that 'pictures exist in reality' 'pictures are a part of reality'. You want evidence for this? Please specify.
-
You are claiming hidden pockets of infinity
I don't understand what that means.
As you are claiming that what we see is an "illusion" the burden is on you to demonstrate your concept.
I need to demonstrate to you that optical magnification can "unmerge" things which appear "merged" with the naked eye?
That objects which cannot be distinguished with the naked eye can be if you use binoculars or a telescope?
Really?
The fact that there is nothing you can easily point to; no studies, examples, or other types of evidence, shows the weakness of the argument.
You are making a claim about a consistent angular velocity of high altitude airplanes.
Where are your studies, examples or other types of evidence?
-
I gave you an example. You agreed with the example. You then pulled the Ancient Greek perspective theory out to tell us something about how perspective operates or scales in the distance and basically shook your finger and pointed at an equation.
Very weak.
-
I gave you an example. You agreed with the example. You then pulled out the Ancient Greek perspective theory out to tell us something about how perspective operates in the distance and basically shook your finger and pointed at an equation.
Very weak.
Eh? What ANCIENT GREEK PERSPECTIVE THEORY are you talking about. The ancient Greeks had no theory of perspective, unless you can provide a citation to one. How many times??
All modern theories are based on assumptions about the propagation of light. If you have a theory about how light travels, then please tell us, but leave the ancient Greeks out of it. They thought that light travels from the eye to the object.
-
Statement 1:
The fact that perspective lines converge is evidenced right there in reality.
Statement 2:
The horizon line isn't an "infinite distance away"...
There's the crux of the matter: where certain lines of perspective appear to converge is the cause of a horizon line on a flat earth. Has to be.
The reason why this is even an issue for you is that you need an explanation for a horizon line at a definite distance (H) on a flat surface; and given that the explanation for that horizon line is Perspective, it must be able to give a non-zero solution for H. It can't be ∞.
But if not ∞, then what is it? It should be calculable. Rowbotham never said, but from his explanation of Perspective and where H lies, I deduced that finite value to be height of eye level times the tangent of 1 arcminute. I can't remember if you agreed or ever even commented. I've never seen you give a finite solution for H. You only declare it's not infinite. That's funny, because we alleged ancient Greek dependents don't believe H is infinite either, but we do give finite values for distance to H without reliance on those ancient Greeks notions of infinite vanishing points.
So let's be clear and not conflate terms to confuse the issue.
The issue isn't whether or not "Greek Infinite Theory" is true or not. I don't need it to be true for a horizon to have a definite, non-infinite distance on a convex surface. Perspective is not the reason for the horizon on a convex surface.
The issue is what causes the appearance of a horizon, and how far away is it on a flat plane? If Perspective is the reason (or part of the reason) for a horizon line on a flat surface, then its YOU who needs for Perspective to solve the distance to the horizon question. Therefore, it's YOU who cannot tolerate the "Greek Infinite Theory." I can tolerate either it's truth or fallacy because my calculation of distance to the horizon doesn't depend on it. Yours does, and it can't be ∞.
It's not up to me or anyone else to have to prove that lines of perspective converge at an infinite distance (although the video by ICanScienceThat does a good job of that) because our explanation for the horizon line doesn't depend on it. What needs to be proved is that horizon line is caused by Perspective.
So prove this.
(http://oi67.tinypic.com/126d9xf.jpg)
Show us that the values for H match what we can observe. They're not matching with observation for me. The RE calculation (that don't rely on vanishing points being at an infinite distance) match reality.
You can start with "horizon always is at eye level", since it's a fundamental principle for H being at a finite distance in Perspective Theory.
... and train tracks don't appear to merge at an infinite distance away. The reality of finite perspective is on our side.
This is sleight of hand logic you use to shift the focus and the burden of proof. If H (a finite point) is due to Finite Perspective, prove it. Calculate the finite distance at which train tracks converge and then measure it to see if it's correct. Calculate the finite distance to the horizon and then measure it to see if it's correct.
You don't get to declare it's correct by default until someone can prove that the ancient Greeks were correct. We don't need Greek Perspective truth to refute you. That's a bogus issue you've raised to insulate yourself from bearing the burden of proof yourself.
If H is finite, show me. I agree it's finite, but that's because I don't agree an infinite VP has anything to do with H. You need lines of convergence to coincide with H. I don't. You need ancient Greeks to be wrong. I don't. You say Perspective gives H a finite value. Fine. Prove it. Calculate a finite value for H using Perspective. Don't deflect by demanding that skeptics disprove the ancient Greeks. That doesn't protect you from having to defend yours (and Rowbotham's) Perspective explanation for finite H.
There is no evidence whatsoever for this infinity nonsense. None. You need to speculate that it exists, whereas we can see that the lines converge.
There is no evidence whatsoever for Perspective being the reason for a horizon line and why ships disappear behind it hull first or why the sun sets behind it bottom first.
There's no evidence whatsoever that the horizon line is always at eye level.
There's no evidence whatsoever for Perspective being the magic, ad hoc solution for any discrepancy between what is observed and what would be predicted to be observed on a flat surface.
If you want to claim Perspective gives finite distances for vanishing points, and that a point on the horizon line is one such finite distance, the calculate it. Predict it and then show that the calculated prediction is true. Don't hide behind ancient Greeks and offer vague, indefinite claims and demand it be disproved vice having to bear the burden of proving it. Show that Perspective works to produce a value for H that can be checked for accuracy. We do it all the time in RE, and never have to rely on lines of perspective converging at infinity.
-
I gave you an example. You agreed with the example.
I agreed that:
It's widely observable that overhead receding bodies move at a more constant pace into the horizon the higher they are.
Yes. True. My diagram shows why that's true. But the claim in the Wiki that the speed of the sun is constant because:
The sun moves constant speed into the horizon at sunset because it is at such a height that already beyond the apex of perspective lines. It has maximized the possible broadness of the lines of perspective in relation to the earth. It is intersecting the earth at a very broad angle.
Is nonsensical. It's actually just a complete gibberish sentence. I wouldn't even know how to go about trying to test that. What does it even mean? What you're doing is taking an observation and then making up some gibberish explanation which is impossible to test. It's like me saying that rainbows are created by invisible rainbow pixies which come out when it rains, but only if it's sunny too. And they line themselves up in a circle and shine their little rainbow lanterns. Prove me wrong! Well, how? How am I going to test that?
The way things are discovered in the real world are:
1) Make an observation
2) Create a hypothesis which explains that observation.
3) Devise some experiments to test that hypothesis. If the tests fail then back to step 2.
You lot never get beyond the second step. And your hypothesis are just things like "the sun stays the same size even though it's really getting further away because there's a magnification effect which by an amazing coincidence exactly counteracts the diminishing size".
Your "evidence" is then that the sun remains the same size! Well we know that, that's where you started! It's completely circular reasoning.
-
I'm glad to see that the video sparked a conversation at least. I was rather hoping that people would try the experiment. I figure if you participate, you're less antagonistic towards the results. So that part didn't work out... now let's discuss the results...
But you already know what I'm going to say. Where did the Ancient Greeks ever provide evidence for their perspective model?
Lets just agree not to have that conversation again for the 100'th time and agree that the Ancient Greek's Continuous Universe model is full of assumptions which have not been demonstrated.
Did you notice that in the video, I made no mention of the Ancient Greeks or a perspective model at all? This video was all about doing it empirically. That's the zetetic way right? Since the logical reasoning behind WHY this happens is controversial, let's shelve that for now. Let's just discuss what we saw first.
What we see very clearly is that apparent sizes (and apparent distances of any kind) shrink with distance from the viewer. We further showed that apparent sizes are inversely proportional to the distance from the viewer. We didn't use any theory to arrive at this. This comes from photographs and measurements.
It's widely observable that overhead receding bodies move at a more constant pace into the horizon the higher they are. For an example imagine that someone is flying a jet into the distance at an illegal altitude of 300 feet. He seems to zoom by pretty fast when he is flies over your head, only slowing down when he is off in the far distance.
Now consider what happens when a jet flies over your head at 45,000 feet. At that altitude a jet appears to move slowly across the sky, throughout its extent, despite that it is traveling at the same speed as the previous plane. With greater altitude the plane seems to move more consistently across the sky. It does not zoom by overhead, only seeming to slow when in the far distance.
Does our photographic observation match the example of planes flying overhead? Yes. Perfectly. As high as any plane can fly, this observation matches it.
When it is directly overhead at 300 ft, it is 300 ft from you. We'll call the apparent speed at that point s.
When the plane moves forward 300 ft, its distance from you is now 424 ft, and that will make its new apparent speed 0.707s.
Let the plane get forward 1000 ft, and its distance from you will be 1044 ft giving it an apparent speed of 0.287s.
"He seems to zoom by pretty fast when he is flies over your head, only slowing down when he is off in the far distance." Check.
Now consider the plane at 45,000 ft. Directly overhead, its apparent speed will be 0.00667s.
Let that plane move forward 300 ft, so it is now 45,001 ft from you. Its apparent speed will be 0.00667s. (It's lower, but you must go past 3 significant figures to see it.)
Let the plane get to 1000 ft in front of you. Its distance is 45,011 ft from you. Apparent speed 0.00667s. (Still lower, but not quite showing to 3 significant figures yet.)
"With greater altitude the plane seems to move more consistently across the sky. It does not zoom by overhead, only seeming to slow when in the far distance." Check.
Quick review... how did I get all those apparent speeds? They come from speed = distance/time. "apparent speed" = "apparent distance" / time. Simply take the inverse relationship between "apparent distance" and distance from viewer, and apply that. Recall that we got the inverse relationship not from any theory, but from empirical evidence.
Did my lego's really show that? Actually they really did. From the legos, I discovered the inverse relationship between apparent distance and distance from the viewer. I tested this with different ranges of size and distance, but certainly not out to anything close to 45,000 ft. But when I applied what I saw at 1 ft, 10 ft, and 100 ft to your example of 45,000 ft; the results worked! If you take a video of a plane travelling overhead, you could validate this.
But I only measured the heights of objects getting farther away from the viewer horizontally. Could it be different for different directions? Why not investigate? You can measure the widths of objects instead of heights, and you'll get the same result. Measure the apparent distance between the objects, and the result is the same. Do the experiment pointing the camera up vertically instead, and see if the results are any different.
-
Some quotes related to Euclid's parallel line postulate courtesy of the Department of Mathematics at UC Riverside:
http://math.ucr.edu/~res/math133/geometrynotes05a.f13.pdf
We have already mentioned in Section II.5 that the final assumption in Euclid’s Elements (the so – called Fifth Postulate) is far more complicated than the others. Furthermore, the proofs of the first 28 results in the Elements do not use the Fifth Postulate. In addition, there are general questions whether this postulate corresponds to physical reality because it involves objects which are too distant to be observed or questions about measurements that cannot necessarily be answered conclusively because there are always limits to the precision of physical measurements.
A nice quote from Immanuel Kant:
"The concept of [Euclidean] space is by no means of empirical origin, but is an inevitable necessity of thought."
Kant, Critique of Pure Reason (1781)
Another description (https://www.math.uh.edu/~shanyuji/History/h-33.pdf) illustrating the parallel line postulate.
As we can see, it is candidly admitted that this idea is not empirical. It is a hypothetical house of cards.
-
Some quotes related to Euclid's parallel line postulate courtesy of the Department of Mathematics at UC Riverside:
http://math.ucr.edu/~res/math133/geometrynotes05a.f13.pdf
We have already mentioned in Section II.5 that the final assumption in Euclid’s Elements (the so – called Fifth Postulate) is far more complicated than the others. Furthermore, the proofs of the first 28 results in the Elements do not use the Fifth Postulate. In addition, there are general questions whether this postulate corresponds to physical reality because it involves objects which are too distant to be observed or questions about measurements that cannot necessarily be answered conclusively because there are always limits to the precision of physical measurements.
A nice quote from Immanuel Kant:
"The concept of [Euclidean] space is by no means of empirical origin, but is an inevitable necessity of thought."
Kant, Critique of Pure Reason (1781)
A good description illustrating the parallel line postulate (https://www.math.uh.edu/~shanyuji/History/h-33.pdf).
As we can see, it is candidly admitted that this idea is not empirical. It is a hypothetical house of cards.
Tom, I understand that you have strong objections to the theory behind perspective. So instead of fixating on that, let's instead look at the empirical evidence. That was the entire point of the video. Let's focus on the evidence, please.
-
A separate discussion on the parallel postulate would be interesting, now Tom has raised it.
-
Tom, I understand that you have strong objections to the theory behind perspective. So instead of fixating on that, let's instead look at the empirical evidence. That was the entire point of the video. Let's focus on the evidence, please.
Tom,
You originally signed up to participate and you filled out the pre-experiment questionnaire. But you didn't follow-up and contribute with an observational input of your own.
Maybe I'm slow on the uptake, but for an empiricist, you sure do do a lot of "imagine this..." and "pretend that..." You like analogical models and thought experiments. I do too, as long as they correctly model what it is they are supposed to be modeling. (Optical artifacts of a camera or camera lense, for instance, do not model light interacting with an atmosphere.)
A model goes a long way toward creating an experiment and predicting an outcome, so that when you actually do perform an experiment and collect data, you can see if your model supported whatever theory or expectation you might have had. But it has to go beyond the paper and beyond the thought experiment, particularly if you champion empiricism. Maybe you don't have to do it personally. You may be physically unable or lack access to resources necessary, but if someone else does, you/we should be able to examine and analyze that data, that experimental setup. It can't be just an anecdotal "I did x and saw y".
Your abandonment of this experiment and your after-the-fact critique are disappointing.
This topic has brought this wiki page (https://wiki.tfes.org/Constant_Speed_of_the_Sun) to my attention. I don't believe I had seen it before. What is the foundation for this claim, which has survived unedited since the page's creation:
The sun moves constant speed into the horizon at sunset because it is at such a height that already beyond the apex of perspective lines. It has maximized the possible broadness of the lines of perspective in relation to the earth.
Does this suggest that there is a distance/range threshold at which point observations based on angular dimensions are different from observations closer than that threshold? If so, what distance is that and how is that derived? Even if there isn't a derivation of such a threshold, how is this claim substantiated?
-
This topic has brought this wiki page (https://wiki.tfes.org/Constant_Speed_of_the_Sun) to my attention. I don't believe I had seen it before. What is the foundation for this claim, which has survived unedited since the page's creation:
The sun moves constant speed into the horizon at sunset because it is at such a height that already beyond the apex of perspective lines. It has maximized the possible broadness of the lines of perspective in relation to the earth.
That’s an extraordinary claim, and confirms my interpretation of the perspective theory. According to the theory, ‘lines of perspective’ don’t just exist in the painting or on the screen: they exist in reality. So when you see the railway lines recede into the distance, they really are converging, i.e. the railway lines themselves, not just in the picture. They meet at a finite distance. Therefore it is possible for real objects to lie beyond these real perspective lines, by ‘maximizing the possible broadness of the lines of perspective’. This explains how the sun moves.
It’s an extraordinary idea. I don't know what to say.
-
Tom,
You originally signed up to participate and you filled out the pre-experiment questionnaire. But you didn't follow-up and contribute with an observational input of your own.
.........
Your abandonment of this experiment and your after-the-fact critique are disappointing.
Unfortunately the steps in the instructions were not entirely clear (https://i.imgur.com/i738kKr.gif) and I fizzled out. It also seemed to be a bit pointless at the time because there was no real context. Now that this video has given context to why he wanted me to measure legos/other objects, I've given my response. If you guys wanted to ask us this question, you should have just come out and asked it.
I would have measured the legos and other objects the same as you and the author did. I don't see how me submitting another lego picture would have helped, without giving us more context on what was being tested.
It was a bit obvious that the author had some kind of agenda in mind that he was trying to set us up for -- but I was going to play along anyway. I gave you our response here in this thread. I'm not sure why I was actually needed to measure legos too? We aren't denying what was measured, so I don't know why our participation was needed?
-
It was a bit obvious that the author had some kind of agenda in mind that he was trying to set us up for -- but I was going to play along anyway. I gave you our response here in this thread. I'm not sure why I was actually needed to measure legos too? We aren't denying what was measured, so I don't know why our participation was needed?
Sadly, I was afraid of that. I knew that many people wouldn't trust me if I just told you how I think perspective works. It was my hope that you would agree to perform the test and would trust your own results. I had hoped this would create a better starting point from which to discuss how perspective works rather than the usual argument style.
As I should have suspected, people sensed that the test was likely to challenge their world views, and refused to participate. So at least for now, that approach seems to be a complete failure. The lack of trust between us runs very deep, and I've come to realize that this lack of trust is a major component of the FE movement. My "agenda" was to try to create a bridge of trust between us by cooperating on a simple experiment.
I'm glad you accept the results at least. I will point out that no FE (or undecided) who filled out the pre-experiment form already knew this material. I did get one completely blank submission, so maybe that was Tom. Maybe Tom already knew this material, but I'm somewhat hopeful that at least somebody might have learned something new.
-
Hi, I only registered in order to leave a idea about a perspective experiment. It requires you to find a really deep hole, or digging a hole. If you could place series of thin lines within such a hole, and use your camera to look inside a hole, you might find that parallel lines get closer and closer to each other. Even better if thin lines represent height.
Holes are independant of the shape of the earth. Whether the earth is flat or not, there is zero curvature.
-
I assume a flat world for this:
Perspective is a projection from real world to an imaginary plane. A vanishing point does only exist in the image plane. The vanishing point is infinity in real world. Real world straight lines are also straight lines in the image plane.
So high flying objects, following a straight line parallel to the ground in real world, will also follow a straight line in the image plane, ending in the vanishing point (I deliberately avoided the word intersect).
So far so good, but now:
Distances in real world get projected to the image plane, so that these get shorter and shorter the farer away these are from the observer. They get so tiny, that near the vanishing point the tiniest stretch of line still represents a vast distance in real world.
The "flying" object will never reach the vanishing point. It will appear to get slower and slower, when approaching the vanishing point.
More probable the object will get smaller and smaller in the distance and "vanish" due to limited eye/camera/telescope resolution or atmospheric haze... Or gets lost behind the Globe Earth curvature/horizon.
-
I assume a flat world for this:
Perspective is a projection from real world to an imaginary plane. A vanishing point does only exist in the image plane. The vanishing point is infinity in real world. Real world straight lines are also straight lines in the image plane.
So high flying objects, following a straight line parallel to the ground in real world, will also follow a straight line in the image plane, ending in the vanishing point (I deliberately avoided the word intersect).
So far so good, but now:
Distances in real world get projected to the image plane, so that these get shorter and shorter the farer away these are from the observer. They get so tiny, that near the vanishing point the tiniest stretch of line still represents a vast distance in real world.
The "flying" object will never reach the vanishing point. It will appear to get slower and slower, when approaching the vanishing point.
More probable the object will get smaller and smaller in the distance and "vanish" due to limited eye/camera/telescope resolution or atmospheric haze... Or gets lost behind the Globe Earth curvature/horizon.
Yes that all sounds correct and matches what we found in the experiment... If I follow you correctly at least.
-
I gave you an example. You agreed with the example. You then pulled the Ancient Greek perspective theory out to tell us something about how perspective operates or scales in the distance and basically shook your finger and pointed at an equation.
Very weak.
You are constantly pulling the Ancient Greeks into this, why?
We live in the modern age and have a perfect understanding of perspective.
You however are pulling out flat earth perspective, you claim that the sun shouldn't change in size because it is beyond the apex of perspective lines, you however have no proof of this, no math to support it, it is simply a claim made by flat earthers because they can't explain why the sun doesn't change in size.
Meanwhile, you claim that we have no proof of perspective lines receding to infinity, which is just a bullocks claim as it is impossible to provide an empirical proof of this.
We know how perspective works, it is extremely simple, all you need are straight lines from the observer to the viewed objects and the angles of those lines in 3 dimensional space. From this we can calculate and simulate every observable perspective.
Now how does your perspective work?
-
I can share my artistic point of view and experience. Only lines parallel to the eyesight line are guaranteed to be seen as straight. Everything else is usually bended. It is rare to observe perfectly straight lines in real world.
For artists, notion of perspective is obtained through long practice. And at the end, it is something like a feeling about where lines should go.
In my drawings I use perspective like eyefish/360 degrees vision, but a very slighter version of it.
To determine if the horizon is a straight line, one should look to a point that is part of the horizon(the farthest distinguishable detail one can see that is supposed to "sit" down on earth surface). Looking down or up from the horizon will bend it.
(By the way, when we are looking to earth from space, a round plane earth should give us a curved horizon too. So in my own opinion, if earth is planar it has to be pretty large, so the detail-vanishing point to make the horizon appear straight. It "solves" the gravity problem too.)