Moon Illusion

After years of being demonized by friends and family for saying that the moon is not bigger when it is on the horizon, that it is just an optical illusion, I am happy to be vindicated

I thought the various explanations were fascinating, though I think the commenter's suggestion that it is a glitch in the matrix is the most compelling.

Hat tip:  Tom Kirkendall


  1. mahtso:

    I did not watch the video, but you can prove the blogger's point by holding your thumb or say a cigarette light up to the moon when it appears large on the horizon - what you will see is the moon "shrinking"

  2. Another_Brian:

    Wait just a minute. You personally know people who thought the moon physically changed size based on it's position relative to someone looking at it?

  3. Mercury:

    Well, sort of. The moon never changes size of course and there is a horizon illusion but because of its elliptical orbit the moon looks 14%ish bigger at its perigee because it is actually closer to the Earth.

    Don't get into a similar argument about why the sky is blue because that turns out to be a much, much more complex issue.

  4. Elam Bend:

    I was taught to bend over and look at the setting moon through your legs (so the horizon appears on top). Kills the illusion.