Why is snow white?
Here are some facts about snow and why it is whiteWhy is snow white? After all, there are so many other more interesting colors to choose from. For a bunch of ice crystals that are stuck together, there is certainly a lot of romanticism associated with snow. White Christmas by Irving Berlin, Let it Snow and other wintry classic songs all render a romantic glow to that white stuff the weathermen warn us about. But let’s get down to the order of business. Why is snow white?
Visible light from the sun is composed of a series of wavelengths of light and our eyes detect these varying frequencies as different colors. The particular atoms and molecules that comprise specific objects have different vibration frequencies. In the case of light energy, the molecules and atoms absorb a certain amount, depending on the frequency of the light. They then emit this absorbed energy as heat.
When light frequencies are not absorbed, light travels all the way through the material, so the material is clear. In most solid material, the particles re-emit most of the unabsorbed photons out of the material, so no light, or very little light, passes through and the object is opaque. The color of an opaque object is just the combination of the light energy that the object's particles did not absorb.
Since snow is frozen water and frozen water is clear, why does snow have a distinctive color?
Snow is a cluster of individual ice crystals clumped together. When a light photon enters a layer of snow, it goes through an ice crystal on the top, which alters its direction slightly and transmits it onto a new ice crystal, which does the same thing. All the crystals bounce the light everywhere, altering all of light frequencies. The result is that the “color" of all the frequencies in the visible spectrum combined in equal measure is white. This is the answer to the question of why is snow white.
As light hits the snow on the ground, light reflects everywhere around it and no single wave length of light gets absorbed or reflected with any consistency. Most all of the white light from the sun hitting the snow will reflect back to the ground, making the fallen snow appear white. Although this explains why snow is white, it should be noted that depending on certain conditions, snow could take on other hues as well. In some instances, impurities in snow can cause it to appear a different color. For instance, algae growing on snow can render reddish, orange, or green hue. Dirt and debris near a road can make snow appear gray or black.
When compacted, snow can take on a blue hue, which is seen in the blue ice of glaciers. Glacial ice is not the same as snow ice. As light enters a deep layer of ice, the light gets distorted, causing more and more of the red end of the color spectrum to be absorbed. As this process continues, more blue wavelengths occur and reflect back to the eyes. The color of glacier ice will then appear blue.
In conclusion, the answer to the question of why is snow white concerns the translucent nature of the tiny ice crystals that comprise it. Light does not easily pass through ice and instead bounces back and forth within the crystallized formation. This process causes some light to be reflected and other light to be absorbed. The bouncing among millions of ice crystals leads to a neutral ground between the color spectrum of red on one side and violet on the other. This translates into the white we all come to recognize as indicative of snow.
Why is snow white is an interesting question.
The next time you pass a snowman along the road, give a nod of respect and attempt a discussion on the matter. Chances are, not even he can tell you why it always seems to snow when you need to be out in it except if you are a kid, in which case, a heavy snowfall is a blessing!