Question

Give reason for the following :-

I)The sun appears reddish at sunrise or sunset

ii) The sky appears dark instead of blue to an astronaut ? ​

Answer 1

$\sf{\large {\underline {REFRACTION\: AND \: REFLECTION}}}$ :

( i ). The sun appears reddish at sunrise and sunset due to the phenomenon of Atmospheric Refraction of light. Red having the maximum wavelength and lesser frequency, it deviates minimum whereas Blue colour having minimum wavelength and maximum, deviates more on refraction. So, red color reaches our eyes whereas blue gets scattered.

Wavelength = 1/ frequency

( ii ). The sky appears dark instead of blue because in sky there is no atmosphere. Due to absence of atmosphere and atmospheric particles for refraction, no refraction takes place there. That's why no light gets reflected or refracted ( no bouncing back of light occurs) . So, the sky appears dark.

Answer 2

1 during sunset /sunrise sun is near the horizon.so light has to travel a longer distance and near the horizon most of the blue light would be scattered away. the light that react aur eyes would be red in colour.

2 because there is no atmosphere and hence no scattering of light takes place in space