> It’s wrong, he told me, because “you can get the illusion if you have only one eye. Simple!”

What?

Binocular vision is used for mid-range (something like 3-6 feet) depth perception. Other visual clues are used for further away objects, like occlusion. His counterargument against the first hypothesis described is invalid.

ISS astronaut Karen Nyberg commented on this illusion (or rather the lack of it, from space) earlier this year:

https://twitter.com/AstroKarenN/status/441338200242393088

I don't see this illusion. I've never thought that the moon looked bigger when it was close to the horizon. I think my girlfriend thinks I'm saying it to be difficult but I honestly don't see it. Does anyone else have this experience?

Not me. Do you see the Ebbinghaus illusion?

http://en.wikipedia.org/wiki/Moon_illusion#mediaviewer/File:...

I've never really strongly seen the moon illusion either - maybe it looks just a tiny bit bigger, but certainly not significantly bigger.

I get the same thing with the Ebbinghaus illusion you linked to - there seems to be a very slight difference between the diameter of the two centre circles, but only perhaps 1/4 of the width of the lines. If I stare at it for a while, even that difference goes away. Is that what you see too, or is the effect stronger?

No, that's what I see too, though I can't will myself to not see it. I get a stronger effect with the colored version on this page: http://en.wikipedia.org/wiki/Ebbinghaus_illusion

I do see that, yes. Interesting!

Nope, I've never seen it either.

>who had constructed a perceptual model in which the sky was contiguous with the horizon, so that the moon was placed, as it were, in front of the sky, occluding it.

I have been looking at this sentence for a few minutes, and still have no idea what it is saying.

I was confused by that as well. I think it's trying to describe this effect: http://en.wikipedia.org/wiki/Moon_illusion#mediaviewer/File:...

Thanks, I was wondering about that, too. That diagram helps explain it. But I still don't understand circle 3. According to perspective rules, shouldn't the moon appear much, much smaller, since it's so far away?

Circle 3 is saying that's how big the moon would look like if it was actually proportionally sized to the cloud, and actually "in the sky" as opposed to be 238,000 miles away.

Basically, the argument here is that we judge the size of things in the sky under the assumption that they are in the sky. But the moon is not; it does not follow the perspective rules of things that are actually close to us. The figure is saying that when we see situation 1, our brain assumes situation 3 will hold.

Keep perpetuating the lies...

I will continue to fight you and your 'social media' buddies.

The truth: http://whyfiles.org/2010/i-saw-a-photo-of-the-sun-rising-abo...

That image of San Francisco has huge mountains blocking the way, so you can't even see the moon at the horizon. Ridiculous!