Super-Black Is the New Black
Super-Black Is the New Black
Published on January 09, 2018 at 11:48PM
Feathers on birds of paradise contain light-trapping nanotechnology that makes some of the deepest blacks in the world, a new study has found. From a report: Blackbirds, it turns out, aren't actually all that black. Their feathers absorb most of the visible light that hits them, but still reflect between 3 and 5 percent of it. For really black plumage, you need to travel to Papua New Guinea and track down the birds of paradise. Although these birds are best known for their gaudy, kaleidoscopic colors, some species also have profoundly black feathers. The feathers ruthlessly swallow light and, with it, all hints of edge or contour. By analyzing museum specimens, Dakota McCoy, from Harvard University, has discovered exactly how the birds achieving such deep blacks. It's all in their feathers' microscopic structure. A typical bird feather has a central shaft called a rachis. Thin branches, or barbs, sprout from the rachis, and even thinner branches -- barbules -- sprout from the barbs. The whole arrangement is flat, with the rachis, barbs, and barbules all lying on the same plane. The super-black feathers of birds of paradise, meanwhile, look very different. Their barbules, instead of lying flat, curve upward. And instead of being smooth cylinders, they are studded in minuscule spikes. These unique structures excel at capturing light. When light hits a normal feather, it finds a series of horizontal surfaces, and can easily bounce off. But when light hits a super-black feather, it finds a tangled mess of mostly vertical surfaces. Instead of being reflected away, it bounces repeatedly between the barbules and their spikes. With each bounce, a little more of it gets absorbed. Light loses itself within the feathers. McCoy and her colleagues, including Teresa Feo from the National Museum of Natural History, showed that this light-trapping nanotechnology can absorb up to 99.95 percent of incoming light.
Published on January 09, 2018 at 11:48PM
Feathers on birds of paradise contain light-trapping nanotechnology that makes some of the deepest blacks in the world, a new study has found. From a report: Blackbirds, it turns out, aren't actually all that black. Their feathers absorb most of the visible light that hits them, but still reflect between 3 and 5 percent of it. For really black plumage, you need to travel to Papua New Guinea and track down the birds of paradise. Although these birds are best known for their gaudy, kaleidoscopic colors, some species also have profoundly black feathers. The feathers ruthlessly swallow light and, with it, all hints of edge or contour. By analyzing museum specimens, Dakota McCoy, from Harvard University, has discovered exactly how the birds achieving such deep blacks. It's all in their feathers' microscopic structure. A typical bird feather has a central shaft called a rachis. Thin branches, or barbs, sprout from the rachis, and even thinner branches -- barbules -- sprout from the barbs. The whole arrangement is flat, with the rachis, barbs, and barbules all lying on the same plane. The super-black feathers of birds of paradise, meanwhile, look very different. Their barbules, instead of lying flat, curve upward. And instead of being smooth cylinders, they are studded in minuscule spikes. These unique structures excel at capturing light. When light hits a normal feather, it finds a series of horizontal surfaces, and can easily bounce off. But when light hits a super-black feather, it finds a tangled mess of mostly vertical surfaces. Instead of being reflected away, it bounces repeatedly between the barbules and their spikes. With each bounce, a little more of it gets absorbed. Light loses itself within the feathers. McCoy and her colleagues, including Teresa Feo from the National Museum of Natural History, showed that this light-trapping nanotechnology can absorb up to 99.95 percent of incoming light.
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