sky blue sky

The molecules which make up 99% of the earth's atmosphere do not absorb any wavelengths of visible light. Molecules in the air are not like indigo molecules which absorb red light and give blue cloth its color. Molecules in the air are not pigments. However, molecules in the air do scatter blue light more strongly than red light. This means that white sunlight has its blue components scattered to the side while its red components keep traveling straight. White sunlight bathes the atmosphere of the earth. The sky is blue because molecules in the air scatter blue to your eyes more than they scatter red.

twenty/blue