Moon illusion

[uslic001]

If you look at the moon on the horizon upside down through your legs the illusion that it is large goes away.

[gr33nman]

And if you drop your trousers while you are doing that, the people behind you can see the man in the moon

[varunrau]

Now you're just trying to make me look silly!

[todd2012]

Back when I was an MIT undergrad in the early 1970's I got a ride back to eastern New York for Thanksgiving or Christmas break with several other MIT students. That evening, the moon appeared very large, and I mentioned it was just an illusion. (I had read the July, 1962 issue of Scientific American growing up and knew about the illusion--it was the cover story.) Try as I might, I could not convince the others in the car that it was an illusion.