Question

Using the phenomenon of scattering of light, explain why there is a difference in the colour of the sun as it appears during sunrise and at noon.

Answer 1

During the sunrise, the sun is located near the horizon of the Earth. Hence, light has to travel a long distance through the Earth’s atmosphere. During sunrise, when the white sunlight falls on suspended atmospheric particles, blue colour light scatters out in deep space, while red colour light scatters less, and reaches the observer on the surface of the Earth. Hence, when this less scattered red light reaches our eyes, the sun and its surroundings appear to be reddish.

But at noon, when the sun is located overhead, the sun does not appear reddish in colour but it appears white. This is because light travels a relatively shorter distance when located overhead. Because of this reason, the scattering of blue, as well as red light, is much less when the sun is located overhead.