polar-bear.jpgThe answer seems to be yes! Even though polar bears are white, their hair is actually colorless. I found this out by looking at a great site, Everyday Mysteries, run by the Library of Congress. You can browse tons of questions, and their interesting science answers, compiled by the expert reference librarians at the Library of Congress. Aren’t librarians great?

Here’s a link to the polar bear posting itself. The reason we can’t see through the “transparent” hair directly to the polar bear’s skin (eek! naked polar bear!) is that the hairs are hollow. The air inside the hollow space in the hair bounces the white light from the air back to our eye, sort of like millions of tiny mirrors tilted at tons of different angles. The result is that we see a white bear.

In that same LOC posting is an interesting tidbit — bears at some zoos were turning green! Why? There was algae growing inside the hairs… so those hollow spaces weren’t reflecting white light anymore, but green light. How embarrassing for the poor polar bear.

Note that polar bear hair is NOT a fiber optic. You can see my earlier posting about that.