Suggest a reason for each of the following: i. The sky near the horizon appears to have a reddish colour at the time of sunset and sunshine. ii. The sun is visible to us two minutes before the actual sunrise and two minutes after the sunset.

Question

Philoid · Accepted Answer

(i) During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon. Within the visible range of light, red light waves are scattered the least by atmospheric gas molecules. So at sunrise and sunset, the color of the sky is reddish near the horizon.

(ii) The Sun is visible to people on Earth about 2 minutes before the Sun rises above the horizon and about 2 minutes after the Sun goes below the horizon. This is due to the phenomenon of Refraction of light rays from the Sun.

The density of the atmospheric layer varies with altitude, and hence, the refractive index of the atmospheric layer also decreases. As the light rays travel from rarer to denser medium starting from the sun, they bend more and more towards the normal.

Suggest a reason for each of the following:i. The sky near the horizon appears to have a reddish colour at the time of sunset and sunshine.ii. The sun is visible to us two minutes before the actual sunrise and two minutes after the sunset.

Suggest a reason for each of the following:
i. The sky near the horizon appears to have a reddish colour at the time of sunset and sunshine.

ii. The sun is visible to us two minutes before the actual sunrise and two minutes after the sunset.