Why does the rising moon appear to be so big?

You can find answers to pretty much anything on the internet. But that doesn't mean that they are always correct. A while ago sci-ence.org and the artist Maki posted a comic trying to explain why the moon appears to be bigger when it rises. Unfortunately the explanation that was presented was not exactly correct. Enter the Bad Astronomer, Phil Plait. Phil spotted the error and emailed the cartoonist with the right explanation. And as a responsible writer Maki decided to rewrite the comic. Below you can see the blog post he wrote about the whole thing including the infamous new comic.


Click here for the full comic and article.


Alternatively click here to read Phil Plait's article on the subject.

Here is a small abstract from Phil's blog.

One of my favorite brain-benders is the Ponzo Illusion. You’ve seen it: the simplest case is with two short horizontal lines, one above the other, between two slanting but near-vertical lines. The upper line looks longer than the lower line, even though they’re the same length.
The illusion works because our brains are a bit wonky. The slanted lines make us think that anything near the top is farther away; the lines force our brain to think those lines are parallel but receding in the distance (like railroad tracks). The two horizontal lines are physically the same length, but our brain thinks the upper one is farther away. If it’s farther away, then duh, our brain says to itself, it must be bigger than the lower one. So we perceive it that way.


Idea for this article came from a post by Maggie Koerth-Baker. Read Maggie's articles on Boing Boing