Many pixels have been devoted to exotic materials that could one day make "invisibility cloaks" a reality, thrilling science fiction fans who dream of, say, their own Tardis equipped with a "chameleon circuit." (Time travel, alas, is a thornier issue).
The latest research on this comes from the University of Michigan, where engineering professor L. Jay Guo has developed a "perfect black" type of cloth that can render a 3D object "invisible." Guo's work is described in a new paper in Applied Physics Letters.
It's basically a black carpet made out of carbon nanotubes (CNT), capable of absorbing 99.9 percent of the light that hits it. "It's not cloaking, as the object can still cast a shadow," Guo cautioned. "But if you put an object on a black background, then with this coating, it could really become invisible."