why we see "sun" bigger in morning and evening instead of big in the noon time?

Answer 1

Because the sun shine on different frequency and as the atmosphere absorb the light wave energy the frequency drops.
It just happen that more frequency which fall in between our capability too see is shone in greater amplitude in the morning and evening. When in the noon the sun shine more on greater frequency so we see the sun is shrinking.
If you can see the higher frequency light, or you see it from a planet with no atmosphere, the sun will appear larger in the noon instead.

Answer 2

The sun stay the same size, that is for sure..

But our atmosphere has many types of gas and water.. It can act just like optical lens and cause distortion..

If the sun is nearer to the horizon, it will look bigger because the atmosphere is much thicker..

Atmosphere also cause our sun glow red at morning and evening, and also the blue sky.. If there is no atmosphere, the sky will be black, even at noon..

Answer 3

Earth's Atmosphere distorts the light comming from the Sun causing it to look bigger. All celestial objects should be able to be covered by your ring or pinky finger. Light is distorted by the atmosphere, the sun just looks bigger than it really is. When the sun reaches noon mark the sun is at where the atmosphere is lightest.
Hope that helps

Answer 4

It's an optical illusion. Your brain uses nearby objects to judge distances. Near the horizon, the sun is close to familiar objects like trees and houses; your brain judges the sun to be "close" to those. (Silly brain.) At noon, the sun isn't near any earth-bound objects and your brain adjusts to decide the sun really is far away.

We can tell this is an optical illusion and not a real change in the sun's size because the same effect happens to the moon. Check out the moon today and see for yourself!

Answer 5

This is a variation on what is usually called "the Moon illusion." Our brains enlarge the size of the Moon when it's close to the horizon and familiar objects. In fact both the Sun and the Moon are exactly the same size whether on the horizon or overhead.

Answer 6

It's your brain . . . use the moon sometime. At arm's length a dime is about the same size--look at it near the horizon and then later in the middle of the sky--they are the same. The moon/sun looks bigger near the horizon because of reference. The fact is that we've come to realize that far away things LOOK small, but really aren't. So, when you see the sun as a far away thing, and you have some trees or buildings on the horizon to compare it to, then our brain compensates, and we think "It must be huge!" I know this, because I originally thought it was an atmopheric effect, but it's actually psychological.

Answer 7

It's called 'atmospheric lensing' and it's caused by the atmosphere actually acting as a lens to cause an apparent magnification of the object being looked at. The reason that it's so much more obvious near the horizon is because you are looking through more atmosphere and the curvature is greater near the horizon.

Doug