Why Polar Bear Fur Isn't White скачать в хорошем качестве

Why Polar Bear Fur Isn't White

Polar bears aren't actually white. Their color is determined by the lighting and climate of their surroundings. Science Insider tells you all you need to know about science: space, medicine, biotech, physiology, and more. Subscribe to our channel and visit us at: http://www.businessinsider.com/science Science Insider on Facebook:   / businessinsi.  . Science Insider on Instagram:   / science_ins.  . Business Insider on Twitter:   / businessinsider   Tech Insider on Twitter:   / techinsider   -------------------------------------------------- Following is a transcript of the video: Polar bears aren't actually white.Turns out, they can come in all sorts of colors: yellow, gray, orange, and even green. That's because polar bear fur is transparent and hollow.When light strikes the outer fur some of it is absorbed while the rest is scattered away. The result? The fur can appear as different colors under different lighting. Normally, polar bears look white. That's because their fur is scattering sunlight, which is also white. But on a cloudy day, the bears can look slightly gray. At sunset, they can appear reddish-orange. But lighting is only half the story. Polar bears in zoos have been known to turn green. Concrete floors in their pens scrape against the fur. The abrasions form tiny holes in their hairs, opening a gateway for algae that can live and breed inside. In the Arctic, temperatures are too cold for these algae. But wild polar bear fur can still change color to yellow, thanks to oils from their prey that stain the fur. Perhaps the most surprising thing about polar bears? Underneath all that hair, polar bear skin is actually black. The black skin readily absorbs sunlight to keep the bear warm. Polar bears aren't just the ambassadors of the North Pole. They're masters at manipulating color to survive. Read more: http://www.businessinsider.com/sai FACEBOOK:   / techinsider   TWITTER:   / techinsider   INSTAGRAM:   / tech_insider