Scientists have solved a longstanding mystery about how some fish can seem to disappear from predators. The discovery could help materials scientists and military technologists create more effective methods of ocean camouflage.
The fish use microscopic structures called platelets in their skin cells to reflect polarized light. This kind of light is made up of light waves all traveling in the same plane, like the bright glare you sometimes see when sunlight reflects off the surface of water.
Under the surface of the water, light tends to be polarized. Many fish—and sophisticated modern satellites—have the ability to detect variations in such polarized light.
“Fish have evolved the means to detect polarized light,” says Molly Cummings, professor of integrative biology at the University of Texas at Austin. “Given that, we suggested they’ve probably evolved the means to hide in polarized light. If we can identify that process, then we can improve upon our own camouflage technology for that environment.”
