Because the earth revolves around the sun and the whole earth isn’t always facing the sun it changes that’s why we have night and day and summer and winter etc
The type of relationship between atmospheric density and altitude is therefore inverse relationship. This means an increase in either will decrease the other factor. Density is mass per unit volume, it is difficult to calculate with only altitude 1,291 kilometers given. Else, we could also use temperature and pressure to solve density but they are not provided.
Answer:
It is not a property of light. It is your eyes and brain.
Specifically, the three kinds of cone cells in our eye that are sensitive to different ranges of the electromagnetic spectrum. The fact that there are three means that color is three dimensional, and is the reason the pure colors form a circle even though the spectrum of wavelengths is linear.
Visible light is part of the electromagnetic spectrum; light waves of different frequencies and wavelengths are distinguished as colors by the human eye. A prism can separate the colors of white light (dispersion) because different frequencies of light have different refractive indices for a given material.