Why Is Snow White?


Snow is just a bunch of ice crystals getting together, hanging out and having fun. So why is snow white when ice has no color?

First things first, why are different things different colors in the first pla­ce? Visible light is made up of different wavelengths of light—from the shorter, violet ones to the longer, red ones. When light hits different objects, the different wavelengths have different reactions. Objects absorb a certain amount of light, and absorb certain wavelengths more than others. The wavelengths that aren't absorbed as much (or at all) reflect off the object, and we perceive them as color. When you look at an object, the color you see is the combination of the light frequencies that the object did not absorb.

When light hits snow, it's in for the ride of its life. All those ice crystals that make up snow are translucent, not clear, so the light doesn't pass right through it, but bounces around back and forth off the different crystals. As the light bounces around, some of it is reflected, and some of it is absorbed. No one wavelength is preferentially reflected or absorbed, though, so all the different wavelengths—and therefore all the colors that we can perceive—are reflected to our eyes in equal measure. The color of a combination of all the frequencies in the visible spectrum in equal measure is white, so this is the color we perceive snow to be.