I'm not sure what the best title for this subject is...so I went with "altered perspective".
Tom keeps on waving this video at us - so this thread is an effort to explain (and debunk) that video.
The error it makes is to double-count the "perspective" effect.
I'm going to talk at the video at specific time points into it - so I suggest you open a second browser window with the video running in it and pause at the times I indicate to read my comments:
So listen through to around 1:50 and hit Pause.
The picture he's looking at shows that the further away the object gets, the smaller the angle to the ground it gets. This is reasonable - light travels in straight lines. If we extended the diagram off to the right with more and more equally spaced suns, the angle would get smaller and smaller - right?
At a billion miles, the angle would be a tiny fraction of a degree - at a trillion miles, still smaller - and at INFINITY the angle would be ZERO...or as close to zero as matters (the math term is "Infinitesimal" - one divided by infinity - not strictly zero - but essentially that).
This IS the standard law of perspective. The further two parallel train tracks lead away from you, the narrower the perceived angle between them. But even at a billion miles, they don't quite meet. Only infinitely far from the eye to those train tracks come together.
OK - un-pause the video...stop it again at 2:07 or so.
He just said
"So the drawing is not taking the visual perspective of the observer into account".
But that's not true...as the sun moves further away, the angle decreases until (at infinity) the angle is zero. If this isn't "perspective"...then why is that angle decreasing?
OK - un-pause again...stop again at 2:43.
So he's just added a SECOND 'layer' of perspective. The diagram (which for some reason he can't understand...just like Tom in fact) works perfectly well to reproduce what we see in the real world. Adding ANOTHER layer of "perspective" is double-dipping! Not allowed!
At 2:43, he's just added some suns moving downwards - but the sun isn't moving downwards in the real world - only in the eye of the viewer. The original diagram is showing the path of the actual photons...the rays of light traveling from the sun to the viewer.
OK - so onwards to a picture of a wall...pause again at 3:27.
He's overlaid a side-on diagram onto a sloping wall...WTF? How does that prove anything? You can't just take a 2D side-on diagram and paste it onto a photograph taken at some random angle and demand that they line up perfectly! What kind of a bullshit claim is *THAT*?
If he had blown up the diagram until it was about 20' long and 10' high, so the stick-figure's eye is level with the camera that took the photo - and pasted the giant diagram onto the wall...so both the diagram and the wall are at the same orientation...and THEN taken the photo...guess what would have happened?
Well...let's try that shall we? It takes a bit of fancy 3D graphics work (that's what I do for a living)...but the result is this:
It's hard to reproduce the exact camera angle of the original photo - and the low-res diagram has blurred out horribly because it has to be stretched to match the perspective in the photo - but you can see that the stickman's eyeline matches the eyeline in the photo - and the sun gets closer to the horizon in the same way that the strips on the wall do.
It's not perfect...but you should be able to see what I mean.
So if you could match the camera angles in the diagram and the wall...the result would be perfect...and of course if you do the reverse - and photograph the wall side-on and lay it on top of the diagram, that would be perfect too.
So this stage in his "proof" doesn't prove a darned thing - other than that the guy who made the video is clueless.
Watch again until 3:30.
Now he's just made another mistake. The green sun positions are equally spaced across the photograph - but that's not right.
Equally spaced things should get closer and closer together with perspective...right?
Look again at the original picture of that wall:
Notice that behind the horizontal strip, there are a bunch of vertical supports, which are clearly equally spaced by whoever hung that wall? This is VERY convenient for our proof. (Thanks video guy!)
Suppose I put a red dot over the intersection of each vertical support and the "eye line".
And above each one, I draw green dots for the position of the sun as 1pm, 2pm, 3pm, 4pm, 5pm and 6pm...just like he tried to do. I'm allowing the sun to move the distance between two support strips every hour - which (in the real world) is a constant speed:
What we see is that FAR from reaching the "horizon" at 6pm, the effect of perspective is shortening the *visual* distance between the consecutive sun positions...so although the sun is indeed lowering in the sky - it'll never reach it because it's moving smaller and smaller distances with each hour that passes.
Another way to think about that is that perspective works in both the "X" and "Y" directions...but it also works in "Z":
Equally spaced pillars getting closer together as they get shorter. The number of pillars needed before the height of the building is zero has to be infinite because every time you halve the height of the building, you double the number of columns you need:
This is WHY the FE sun can never set.
Finally. we can connect up some green lines from the eye to the sun - but the result is kinda messy:
The angle by which the sun drops towards the horizon decreases with each hour...so the sun can only reach the horizon after an INFINITE number of hours...which is to say "never".
The problem is that he's guilty of PRECISELY the thing that he falsely accuses the original diagram of. He's using a 2D representation fo the sun on a 3D photograph of a real world thing.
You simply can't do that.
You can prove your point with a 2D diagram - or you can prove it with a 3D photographic visualization - but the instant you mix the two - you screwed up.
So the video is at best misleading. Clearly the guy who made it DOESN'T understand the first thing about how perspective works.
OK - watch again until 4:50.
Notice how at around 4:50 he cheats and adds more lines at the top of the screen than there really are...naughty! And carefully STOPS drawing the lines at the bottom of the screen when they are in danger of revealing his lies. Misleading! Those lines at the top of the screen that are almost vertical...those don't happen in the real world do they?
So the video whitters on and at 5:25, he's back with his incorrect diagram of the sun's motion.
And out at 5:46, he again accuses someone of using non perspective lines on a perspective drawing - while, ironically, his own screwup of PRECISELY THAT is in the background! Love it!
This explanation gets to crazy levels of insanity by 6:36 in the video as he overlays his 2D side-view drawing onto a perspective drawing and tries to extract information from that!
So...RE-BUNKED! (is that even a word?)