Posted on Mar 9, 2022 550
The polar bear is a formidable inhabitant of the Earth’s northern hemisphere. He likes to eat seals , lives on drifting ice floes and is the hero of many cartoons. It would seem that even the name of the bear tells you what color his fur is - white, of course. But would you believe that the coat of a polar bear is not white and transparent?
As you know, the color of a substance is determined by how much of the visible electromagnetic waves the substance can reflect. For example, blue paint does not transmit electromagnetic waves whose length corresponds to the blue color. These waves are reflected and hit the retina of our eye, which, being a kind of receiver of electromagnetic radiation, reads their blue color. For an object to be black, it must absorb all light waves directed at it, and four white - on the contrary, reflect. If the object is transparent, light waves simply pass through it.
Just like a transparent tube filled with air and is each hair of a polar bear. Nature gave the bear this amazing tool, so that he better keep heat. It turns out that if the coat is transparent, then the light must pass through it and reach the skin, which in polar bears is black. But why then, as strange as the question may sound, is a polar bear not black? Every hair on the pelt of the North Pole master, though transparent, is not perfectly smooth. Rays of light are refracted by the minor bumps on the coat, and then they are refracted and then refracted again, and so on. Scientifically, there is a change toward propagation of electromagnetic waves of the visible range. This process is called light scattering.
Finally, the light, barely penetrating the fur, is reflected to the observer who perceives the fur as white. Why white? Because the light that comes to us from the Sun is a combination of light waves of different wavelengths that combine to produce white (read “What Color is the Sun Really?”).
So, isn’t it time to call the polar bear “transparent”?
This is interesting: the same rule applies to snow, which appears white to us, although each individual snowflake is transparent.