Free Republic
Browse · Search
General/Chat
Topics · Post Article

To: SunkenCiv
the cause of the Moon illusion is still poorly understood

I don't think so. Just like the green flash over the ocean, you are seeing light refracting through the atmosphere...kind of like a prism effect. All the different colors represent is the particular wavelength of light.

5 posted on 06/13/2014 5:48:18 AM PDT by gr8eman (A good rant should have the word "crap" in it at least 4 times!)
[ Post Reply | Private Reply | To 2 | View Replies ]


To: gr8eman

The green *has* to be there, for the leaves, otherwise it wouldn’t look like a strawberry. Duh!


6 posted on 06/13/2014 5:31:41 PM PDT by SunkenCiv (https://secure.freerepublic.com/donate/)
[ Post Reply | Private Reply | To 5 | View Replies ]

To: gr8eman

The moon illusion is a psychological effect, not an actual change in the apparent size of the moon. Refraction, atmospheric reddening and extinction cause the various effects of the moon’s ragged edge, squashed shape, and color as it rises and sets, but the moon illusion is the false perception that the moon is significantly larger when near the horizon than high overhead. The latter is entirely in your head; you can “break” the illusion by covering the moon with a finger at arm’s length. Repeat this test when the moon is crossing the meridian later in the evening. You’ll see it’s still about the same size.

If anything, the moon’s apparent size is slightly smaller on average while near the horizon due to differential atmospheric refraction at the higher limb than the lower giving it the “squashed” appearance.

I agree that the description for this one is poorly written though, it’s well understood what causes the moon illusion, even if there may be competing theories as to why it happens within the mind (though even that isn’t really too controversial I think).


7 posted on 06/16/2014 12:55:36 PM PDT by messierhunter
[ Post Reply | Private Reply | To 5 | View Replies ]

Free Republic
Browse · Search
General/Chat
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson