Air molecules scatter short blue light waves in all directions, making the daytime sky look blue.

Sunlight looks white, but it holds every color of the rainbow. These colors travel in waves of different sizes. Blue light travels in short, choppy waves. Red light travels in long, lazy waves. The tiny gas molecules in our air are mostly nitrogen and oxygen. They are the perfect size to bounce the short blue waves around. This bouncing is called scattering. Because blue bounces everywhere, that is the color we see when we look up.