[TheTruthIsOnHere]

Tom, the sun doesn't look lower.  The angle between them just appear to not converge.  Tom, did you try the string like the rest of us?

What are you talking about? Does a plane not look lower when it is over head than when it is off in the distance?

That's a perspective effect. You are claiming that the 93 million mile distant sun is lowered due to a perspective effect. The hallway example, the ceiling example, those are perspective effects, something you are attributing this event to.

Here are some pictures of my living room.  When I look left (first picture) the ceiling line appears to point up upwards.  When I look right (second picture) the ceiling line appears to point upwards.   In reality neither points upward.  If the moon phase was in the left corner and at a right angle to the to the intersection line it would appear to point upwards from my perspective. In reality it would point directly to the opposite corner.

Then why do some people think the Sun and Moon are immune to this perspective effect?

[Rama Set]

They don't.

[model 29]

Then why do some people think the Sun and Moon are immune to this perspective effect?

A good question.  Perhaps one of them could explain why.

They don't.

Tom Bishop seems to think so.

[garygreen]

*if* i used a computer program to draw the scene, i *think* it would look like x and not y.  how do you explain this?!?!?!

something something tatooine.

for one thing, you're wrong.  you're gonna have to render your 3d scene as a 2d image.  when you do that, your straight lines will look curved.

for another thing, it's irrelevant.  no one disagrees that the path light takes from the sun to the moon is a straight line.  this straight line path merely appears curved.  it's the same as how the path of an airplane appears curved from the ground even though it is a straight line.  imagine a beam of light traveling that same path.  it's a straight line path, but it looks curved.  it's also the same as how the line that connects two corners of your room is a straight line, but it appears curved.

i do genuinely love how demanding you are that someone make a computer model for you given your indigence to picking up a piece of twine and holding it in front of your face.

[Tom Bishop]

You keep asking for an explanation without first showing us the proof that a 3d modeling program cannot replicate the effect.

I opened a 3D modeling program and placed a cone pointing at a sphere. No matter where I placed them, no matter how far apart I put them, and no matter where I oriented the camera, I couldn't get the cone to NOT make a straight line path to the sphere. Please help!

[garygreen]

what software?

[Nirmala]

Can you represent the sun, moon and earth at something like these proportions (this image looks like a line but if you click on it you will see it forms a rectangle:

[model 29]

I'm not sure what you were trying to represent there Tom. 

Place two objects above your work plane, a straight line between them, and your point of view level on the work plane looking up at the line and pan left to right.

[Nirmala]

Also, what does the cone represent?

[Flatout]

Here you go, Tom.  I get tangled up on my words a bit but I did it because I love you.

See the second attempt below with maybe a better explanation.

[Boots]

tbh I didn't find that video very satisfying. It did a good job of illustrating what the illusion is, but didn't really explain how or why we could know it was an illusion.

[Flatout]

I'm no awesome video maker so you can critique all you like.  I just finished this one that maybe explains better.  My wife didn't get it so I thought I'd give it another go.  😁
My explanation could be wrong.  The model shows the illusion happening while everything is lined up.

[Jura-Glenlivet]

Excellent!

[Tom Bishop]

It looks like the moon phase is pointing directly at the sun to me.



The next step you perform after this scene is to zoom in on the moon. The moon still looks the same as in the above image, except bigger since you have zoomed in. If we were to then pan to the sun we would be making a straight line path along the red line I have included.

[Tom Bishop]

It appears that when the author zooms in he is not merely enlarging the image, but is actually changing the Field of View in his settings. This is deceptive, as this is applying a fisheye effect.

If we were to apply a simple zoom enlargement in on the moon in my image and then pan to the sun, it would make a simple straight line path to the sun.

The only way to make this work in favor of the Round Earth Theory is by changing the FOV, which applies a wide angle fisheye lens effect to the scene. Again, we are left with the ridiculous claim that when we look out at the universe we are inexplicably looking through a fisheye lens and all straight lines are curved.

[Flatout]

Tom, when you zoom in or out in the perspective view you are changing the FOV.  It's nothing deceptive.  It puts your eye between and below the sun and moon.  It's how you move your point of view forward or backwards within the perspective view window.

Tom, your piece of software will do the same thing if you can place a light source at your cone. 

Putting a line in there will give you a spacial orientation and the brain will understand things for what they are.  This is why we have encouraged you to use a stick or string on the real moon.

BTW, none of this really is revealing the shape of the earth. The exact same effect would be seen on a flat earth with a closer sun.  It's not a proof for either.

That fisheye effect is curlinear perspective.  It's why both corners of your living room ceiling appear to rise up when you look at them individually.  You can only interpreted them as straight when stand back and see both simultaneously. 

[garygreen]

what software?  what field of view?  what projection model?

tom, you can't just tell a computer "hey draw what things really look like."  you have to make a choices about how to display your 3d objects in a 2d image.  how do you know that the choices your program made are the ones that reproduce the way things look?  are you really suggesting that a computer model is a better investigation of the world than direct sense experience?

for example, it looks to me like you're using some cad software.  you're aware that that's probably an isometric perspective, yeah?  and that isometric views are a distortion of the way we actually see things?  amend my remark from my prior post: "you're gonna have to render your 3d scene as a 2d image.  if you want your image to represent the way things appear, then your straight lines will appear curved.  if you want to keep your straight lines straight, then you can't display the object the way it actually appears."

http://deseng.ryerson.ca/dokuwiki/_media/mec222:asc2.pdf

The isometric projection has a standard orientation that makes it the typical projection  used  in  CAD.  In  an isometric  projection,  the  width  and  depth  dimensions  are sketched at 30° above horizontal as shown in Figure 2.2. This results in the three angles at the upper front corner of the cube being equal to 120°. The three sides of the cube are  also  equal,  leading  to  the  term  iso  (equal)  -metric  (measure).  Isometric  drawings work quite well for objects of limited depth. However, an isometric drawing distorts the object when the depth is significant. In this case, a pictorial perspective drawing is better.
...
A pictorial perspective, or simply perspective, projection is drawn so that parallel lines converge in the distance as shown in Figure 2.2, unlike isometric or trimetric projections where parallel lines remain parallel. A perspective projection is quite useful in providing a realistic image of an object when the object spans a long distance, such as the view of a bridge or aircraft from one end. Generally, small manufactured objects are adequately represented by isometric or trimetric views.

and why are we even talking about this?  who cares what you can draw with a computer?  a computer used isometric perspective to draw this staircase.  are you saying this staircase must exist?

[Tom Bishop]

Tom, when you zoom in or out in the perspective view you are changing the FOV.  It's nothing deceptive.  It puts your eye between and below the sun and moon.  It's how you move your point of view forward or backwards within the perspective view window.

Tom, your piece of software will do the same thing if you can place a light source at your cone. 

Putting a line in there will give you a spacial orientation and the brain will understand things for what they are.  This is why we have encouraged you to use a stick or string on the real moon.

BTW, none of this really is revealing the shape of the earth. The exact same effect would be seen on a flat earth with a closer sun.  It's not a proof for either.

That fisheye effect is curlinear perspective.  It's why both corners of your living room ceiling appear to rise up when you look at them individually.  You can only interpreted them as straight when stand back and see both simultaneously.

By increasing the wide angle FOV of a scene you are saying that straight lines above our line of sight are convex, and straight lines below our line of sight are concave. This is not reality. We are not looking through a fisheye lens when we look at two simple bodies in the universe. Straight lines do not curve around our vision depending on how we look at them.

Your simulation of a "celestial sphere" by giving the scene a fish-eye effect is entirely without merit.

[model 29]

By increasing the wide angle FOV of a scene you are saying that straight lines above our line of sight are convex, and straight lines below our line of sight are concave. This is not reality. We are not looking through a fisheye lens when we look at two simple bodies in the universe. Straight lines do not curve around our vision depending on how we look at them.

Your simulation of a "celestial sphere" by giving the scene a fish-eye effect is entirely without merit.

You do realize that a "fisheye" FOV is the same thing as looking one way and then turning your head and looking in a different direction, correct?

Did you gain access to a hallway yet?  When you see this same effect in that hallway, are you going to claim it isn't real?

[Tom Bishop]

You do realize that a "fisheye" FOV is the same thing as looking one way and then turning your head and looking in a different direction, correct?

By widening the field of view the author provided a fisheye effect like so:



That means lines around the line of sight are constantly warping around whatever you are looking. Alternatively, it may be a reverse fisheye FOV -- the author doesn't really say. None of this should be necessary to demonstrate the "celestial sphere". The effect of the "celestial sphere" needs to manifest from a natural consequence of geometry.

Did you gain access to a hallway yet?  When you see this same effect in that hallway, are you going to claim it isn't real?

What are you talking about? If you tape an arrow on a hallway ceiling, it points a straight line path to the end of the hallway. The lines aren't curved to produce an unnatural geometric result, as is with the "celestial sphere".