If you ever visit Southeast Asia, you might come across the whitest thing you’ve ever seen.
And it’s not this guy:
It’s the Cyphochilus beetle, a beetle whose shell is whiter than even the whitest paper, the whitest snow, even the whitest paint.
In fact, it’s brighter than anything that human technology could create using a material as thin as the beetle does.
So what is this material? Well, it’s called chitin.
Chitin is similar to the cellulose, the main material in a plant’s cell wall. It forms complex, tightly-knit networks of filaments that build the shells of crustaceans and the exoskeletons of many insects.
But on it’s own, chitin is not a very good reflector of light at all, so researchers at the University of Cambridge and the European Laboratory for Non-linear Spectroscopy in Italy came together to try to uncover the secret behind the Cyphocilus beetle’s extraordinary brilliance.
What they found was that it was not the material itself that made the beetles look so white, but the geometric pattern in which the chitin filaments had arranged themselves.
The colors we perceive come from the ways in which different colors of light reflect off of different materials.
However, the structure of the beetle’s shell reflects light anisotropically. This means that all the different colors of light get reflected in the same direction, which is why the shell appears to be such a brilliant white (mixing all of the colors of light gives you white light).
But unlike man-made reflectors, which tend to be fairly thick, the beetle’s individual scales are only thousandths of a millimeter thick. This keeps them light, minimizing the amount of energy the beetle has to expend while flying.
Read more from the New Scientist here.