What makes snow white?

by | Dec 24, 2023 | Snow

Snow isn’t actually white

Light reflects off the ice crystals that make up snow. Your eye cone cells pickup all the various wavelengths of color bouncing off the crystals, and so you perceive the snow as white. Snow is not actually white, snow crystals are translucent, but simply reflect light due to their structure.

This effect is produced with polar bears too. A polar bear’s fur is actually translucent, and only appears white because it reflects all visible light.

Understanding color

To completely understand why snow is white you have to understand color. Our eyes detect color as light in the forms of different frequencies and wavelengths.

Different colors are attributed to different wavelengths. For example, red, is in the range of 740-625 wavelength nanometers, and purple, is in the range of 435-380 wavelength nanometers.

White light cannot be limited to a single wavelength. White light consists of wavelengths of various colors. So the wavelength of white light is the full range, 400-800 nanometers. It is a combination of all colours, in approximately equal proportions.

Eye cone cells pickup various wavelengths of light and perceive them accordingly.

Various wavelengths of light are shown in the chart below. White light would incorporate all wavelengths roughly in the same proportions.


Why does snow not appear translucent?

Snowflakes have such a complex structure that light hits the crystal faces and bounces around inside the crystal. The light both refracts and reflects, but most of the light reflects. As the light is from the sun, and the ice crystals are translucent, the snow crystal refract white light, making snow appear white. Snow crystals also bunch up and create more irregularities in the ability for light to pass through them.

Consider a solid block of ice, is translucent and allows some light to reflect but most light to penetrate the ice and be refracted.

Can snow be other colors?

In some cases snow can appear blue or various shades of pink or purple. This is dependent on the angle of the sunlight, and presence of shadows or other obstructions to the sunlight’s path.

Snow blindness

Snow reflects light well, and so just like staring at the sun, you would not want to do it for long. Doing so can cause eye damage from UV rays.

If you are hitting the slopes skiing, or just working on a sunny day in a snowy environment, consider polarized sunglasses or goggles to help eliminate the risk of snow blindness.

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and for all your Calgary snow removal services reach out to CSRS.


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