Question

The sun near the horizon appears flattened at Sunset and Sunrise. Explain. why ?

Answer 1

This is due to the phenomenon of atmospheric refraction. When sun is near the horizon, the distance between the sun and observer is more as compared when the sun is overhead. The rays of light go through several layers of refraction due to which the size appears distorted or more flattened than when its overhead or during noon.
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Answer 2

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1. The earth is surrounded by an atmosphere which is denser near the surface of the earth.

2. When the rays of light from the Sun enter the earth's atmosphere from outer space, they travel from a rarer medium to a denser medium.

3. Hence, they bend towards the normal on refraction.

4. Hence, even when th sun is below the horizon while rising or setting, its rays reach is due to refraction and it appears to be on the horizon.

Therefore, the sun near the horizon appears flattened at sunset and sunrise.

Hope it helps!