Why is the sunset red?
When white sunlight passes through a lot of atmosphere the blue is scattered out of the beam leaving the red in the beam. This is why the sky is blue and the setting sun is red. The scattering occurs at all wavelengths. Violet light is scattered more strongly than blue, but there is less violet than blue in sunlight so the sky is not violet. Indeed there is more yellow and green in sunlight than blue but the combination of the amount of each color present in sunlight times the fraction of power of that wavelength that is scattered makes the sky appear blue. Exploration: Single scattering and the polarization of skylight. Most sunlight scatters only one time from an air molecule on its way from the sun to your eye. Light that scatters once at a ninety degree angle will be polarized. Light that is scattered multiple times is not polarized. Look at the blue sky through polarizing sunglasses Exploration: White opal glass, blue by scattering In a bead shop you can buy glass beads made from
