Why and where does the sun look REALLY big when it rises or sets?
Wednesday, September 14th, 2011 at
11:49 pm
I mean like in the beginning of The Lion King. Why does this happen and where? Does it have something to do with the equator?
Filed under: Bed In A Bag
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It’s an optical illusion in two parts, one of which also affects our interpretation of the Moon.
When the Sun rises or sets, its light is being refracted by the atmosphere, which gives it the appearance of spreading out and being somehow larger. The other part is that while it looks big in the sky, it looks *really* big back down at the horizon, or a mountain, or whatever feature you have, because you can finally put it in perspective. Sort of like having a picture of an animal, but with nothing around it. You may have no idea how large or small it is until another known-size animal comes by, or a biologist puts a foot down next to it, etc. You finally know how large it is… and it IS large, which you can finally see.
This second illusion, the reference size, is why the Moon appears larger when it’s close to the horizon versus its apparent size hanging high in the sky.
It has nothing to do with the equator, just the horizon, and the effect is the same wherever you are. the only slight note is that along the equator the effect will be most pronounced — but it will still be there to one extent or another at any latitude.