Why the sky is blue

When sunlight passes through the atmosphere to reach us, most of the red, orange and yellow light (long wavelengths) passes without being almost affected. However, much of the light of shorter wavelengths is scattered by the gaseous molecules of the air. To any part of the sky that we see, we will be seeing some of that scattered light, which is blue, and that is why the sky is that color. In contrast, the light that comes directly from the Sun lost part of its blue color, so the Sun looks yellowish.When looking towards a point closer to the horizon, the sky looks a paler blue color. This is because, in order to reach us, the light of the sky must in this case pass through a greater quantity of air, and therefore it is dispersed again. The light that reaches us from the sky close to the horizon will then have lost part of its blue color and it will look pale or whitish.