What causes the sky to appear blue?

The sky appears blue because of the scattering of sunlight by Earth's atmosphere. As sunlight encounters the Earth's atmosphere, the shorter blue wavelengths are scattered much more than the longer red wavelengths. This results in the blue light spreading out in all directions and dominating the colors that reach our eyes. This scattering effect is known as Rayleigh scattering, named after Lord Rayleigh, a 19th-century British scientist who first documented the phenomenon. As a result, during sunset or sunrise, the sky appears red or orange because the angle of the sun's light causes more of the longer red wavelengths to make it through the atmosphere to our eyes.

This mind map was published on 22 May 2023 and has been viewed 89 times.