I really wish you would take your own advice. Any projection from three dimensional space onto a two dimensional surface is going to cause distortion, this is what happens on the eye. You can't project the surface of a sphere onto a plane without distorting it, it's just geometrically impossible. Please ask any high school math teacher and they can explain it to you.
Your assertions are trash. A retina is not a flat surface at the back of our eyes. It is a concave surface. There is a difference between a flat surface and a concave surface. I would recommend that you educate yourself better on how it works.
Also, everyone knows that it is possible for there to be a camera lens and configuration that can take a picture of a straight line and keep it straight. Your argument that things are impossible are without merit.
Find me a lens that is 100% distortion free, it doesn't exist. You are unfamiliar with optics and cameras and are falling for marketing drivel. All lenses have distortions, even the best, it's just a matter of how small they can get them to be.
Read your own sources, you keep posting ones that contradict yourself. From that PDF...
"Howerver, a circular object like a ball or person's head, located near the edge of the frame will appear to be somewhat enlarged and will have an oval shape."
So much for your claim that this lens has no distortions. Really, you are using an ADVERTISEMENT for a product as your source? You are literally using what a marketing department wrote and taking it as scientific fact as if they aren't going to simplify and exaggerate their product's abilities. Come on, Tom.
That distortion is immaterial to this discussion. We are not studying the shape of the Moon, we are studying straight line paths across the images.
You claimed the lens had no distortions, I'm showing you that in your OWN SOURCE that is wrong. That's quite material to the discussion, it's showing your claims and assumptions are incorrect.
I'm posting what the manufacturer claims. I have a source. It is clearly possible, and you can easily find many wide angle shots showing straight lines on structures in panoramas. You have no source at all for you claim that it is impossible to keep straight lines as straight. This is just something that you said. Where is your source that it is impossible to keep a straight line straight in a camera image? You keep posting things without source.
I'll ask a second time since you completely ignored it again, do you not see the similarity to the moon-tilt illusion image from your own Wiki? It's exactly what is going on, and is obvious.
And I will repeat this for you again: This is a poor argument. By claiming that we see significant distortion in our vision, you are also suggesting that we can move our head around and get the Moon to point in a variety of different directions.
You calling it a poor argument doesn't make it so.
I'm replicating EXACTLY the moon-tilt illusion with my own light source and camera. Are you claiming those two pictures are nothing alike? Both show curving light paths, both show shadows going in directions other than straight from the source. It should be obvious to anyone looking at it.
And I am not suggesting we can make the moon 'point in a variety of different directions', that is entirely your own confusion speaking there.
I'm showing you exactly what causes the moon-tilt illusion. I can draw arrows and lines on it if that would help you understand it.
You must think that we see the world like this, and that this is what causes it:
If our vision were warped like this then we could just pan our head around and get the Moon to point in a variety of different directions to our warped vision, like we could pan the camera that took that picutre around and get those lines to point differently.
We cannot do this by looking around and putting the Moon in different positions. So you're wrong.
Now this is pretty funny because yes, that is what is projected on our retinas, a distorted view of the world that our brains correct into the images that we 'see'. You are ignoring all the processing of the raw image data that our retinas detect. Do you think that our eyeballs are the entirety of our visual perception? There is a rather substantial portion of our brains devoted to vision you know.
We see straight lines as curves the further from the center of our retina they get, and for very long lines, like across the entire sky, it gets very curved indeed.
As you yourself pointed out, the retina is curved, and what happens to a straight line projected onto a curved surface I wonder?