The sun appears oval at sunrise and sunset,but appears circular at noon.Explain,why?

ans.  the sun appears oval during sunrise or sunset.  this is because of the fact i.e, during sunrise and sunset the sun is at horizon. hence, the light coming from the sun has to travell through comparatively thick blanket of the earth's atmosphere(the sun is at horizon at this time which is the longest distance from an observer to the sun). the light coming from the sun undergoes atmospheric refraction. therefore, as soon as the light falls on the ratina of our eyes the light has aleady been bent (or, got deviated) enough to give us the sensession of the sun's oval vision.

but it appears circular at noon because the light coming from the at noon has to travell through comparatively thin blanket of the earth's atmosphere(the sun is overhead at this time which is the shortest (or, perpendicular) distance from an observer to the sun). hence, no atmospheric refraction of the sun light takes place(as light enters the earth's atmosphere perpendicularly). therefore, as soon as the light falls on the ratina of our eyes the light has not been bent (or, got deviated) to give us the sensession of the sun's oval vision i.e, it looks circular.