Posted by llrrrpp on September 6, 2006, at 23:15:53 [reposted on September 17, 2006, at 21:43:54 | original URL]
This is a full moon time.
the moon is so huge.
I know why, I just forgot. It has to do with how the eye perceives distance, and how our visual system is not able to cope with distances on the scale of the distance between the earth and the moon (300K miles?)
And so, when the moon is on the horizon, we use the trees and the contextual clues to tell us that the moon is pretty big, because usually when you move your head to the side a foot, the image of near things "moves" more than the image of far things.
Motion parallax.
Since the moon doesn't move, it means that it's REALLY REALLY far away, and yet, it still takes up a few degrees of visual space.
Hey: visual system,
What takes up visual space and is really far away?
[something REALLLLLY BIG}Well, when the moon is overhead, we don't have the motion parallax cues, unless there are clouds (doens't the moon look bigger on a cloudy night?)
(((((BigMOOOOON)))))
-ll
poster:llrrrpp
thread:686939
URL: http://www.dr-bob.org/babble/social/20060911/msgs/686939.html