It's snowing up here in Waterloo. I wish I was a polar bear! They aren't only cute but quite interesting guys.
Since they are hard to see in snow, researchers thought some while ago, it would be a good idea to search for them in the infrared. To their surprise, they didn't see much, see the picture to the left. There's eyes, nose, ears, but where is the rest?
Well, this paper
"Radiative Properties of Polar Bear Hair,"
By Preciado, Rubinsky, Otten, Nelson, Martin, and Greif,
BED-Vol. 53, 2002 Advances in Bioengineering, ASME 2002.
summarizes the results of an investigation which shows that polar bear hair has the same radiative properties as snow.
Amazing animals, eh? Though the military was originally very excited about the bears for creating infrared camouflage in cold climates, they quickly lost interest when they discovered that the polar bears could easily be seen in the ultraviolet.
Some more info at this website.
TAGS: PHYSICS, POLAR BEARS