« After 2,000 Years, a Seed From Ancient Judea Sprouts | Main | Scientists Continue Analysis of Kennewick Man »

June 28, 2005

The Illusion of a Big Moon

During Summers months the moon often looks bigger even though the size of the image remains the same:

When you look at the moon, rays of moonlight converge and form an image about 0.15 mm wide in the back of your eye. High moons and low moons make the same sized spot. So why does your brain think one is bigger than the other? After all these years, scientists still aren't sure why.

A similar illusion was discovered in 1913 by Mario Ponzo, who drew two identical bars across a pair of converging lines, like the railroad tracks pictured right. The upper yellow bar looks wider because it spans a greater apparent distance between the rails. This is the "Ponzo Illusion."

While Ponzo's explanation makes sense, the same phenomenon is experienced by airplane pliots. More here.

Posted by Blogorithm at June 28, 2005 04:29 PM

Trackback Pings

TrackBack URL for this entry:


Post a comment

Thanks for signing in, . Now you can comment. (sign out)

(If you haven't left a comment here before, you may need to be approved by the site owner before your comment will appear. Until then, it won't appear on the entry. Thanks for waiting.)

Remember me?