Question

Why does the sky appear dark to the passengers flying at high altitudes ? Please explain in detail .

Answer 1

HELLO THERE!

Superb question: The sky appears dark to people flying at high altitudes.

First, let me ask "Why does the sky appear blue to us?"

The answer is:

As the light rays from Sun reaches the Earth, it suffers successive refractions at each layer of the atmosphere (because density of each layer is different). We know, that white light is polychromatic, consisting of the seven colours VIBGYOR (Violet, Indigo, Blue, Green, Yellow, Orange, Red).

Among these, the mixture of first three colours, i.e., Violet + Indigo + Blue gives an approximate blue colour, which has the shortest wavelength. Hence, in the long way of the sunlight reaching the earth, it gets scattered al over the atmosphere (sky), hence the sky appears blue to observers at Earth.

Now, when a person is at a high altitude, the light ray from the Sun do not have to travel so much distance. So, there is no scattering of blue light, and further, the upper layers of atmosphere are too rare (lower layers are denser). So, the sky appears dark.

(Similarly, as there is no atmosphere in Space, there is no scattering of light, and it appears dark).

HOPE MY ANSWER IS SATISFACTORY....

THANKS!