Question

Why does the sun look bigger when it is rising or setting compared to the sun's size during the afternoon?

Answer 1

Answer :

This is due to an illusion of human perception.

When the Sun is low, we are under impression that it is far away. When the sun is overhead, we are tricked into thinking that it is closer. But we know for a fact that the Sun is always the same size physically. So the same sized object far away (the red Sun on the picture above) will be perceived as much larger than when close (the yellow Sun).

The following illustration can help you understand it better.

Here, Length of the Yellow line segment is same. But, its size looks different due to the same reason as explained above.