Shades of Harry Potter! Scientist invents Invisibility Cloak!

Disappearing Act From Japan, a coat that will make you—and many other things—look invisible By Kay Itoi NEWSWEEK INTERNATIONAL June 30/ July 7 issue — Who hasn’t wanted to spy on others without being seen himself? Nobody, which is why Susumu Tachi’s new invention—an invisibility cloak—made waves earlier this year. Tachi, a professor of information physics and computing at the University of Tokyo, had one of his students put on the cloak and turn semitransparent while photographers snapped pictures. He’s quick to point out, though, that his research is not about fashion. “I showed the coat to explain the concept,” he says. He is working on the bigger problem of “optical camouflage,” a technology that may be useful for hiding unsightly walls and heavy equipment, or for allowing workers to “see through” objects.

THE KEY TO OPTICAL camouflage is retro-reflective material, which sends light rays directly back toward their source, regardless of their incident angle. If basketball backboards were retro-reflective, Kobe Bryant’s layups would bounce right back into his face instead of the net. Once Tachi drapes retro-reflective material over an object, he uses a camera to take a video image of whatever lies behind it, and then projects that image onto the front fabric. To an observer wearing a special head-mounted projector, the object appears semitransparent.

Optical camouflage is the latest development in the field of augmented reality—the practice of superimposing virtual information, such as graphics, audio and other sense enhancements, onto the real world. “There’s an enormous potential for applications with this technology,” says Tachi. Retro-reflective material is common: cops, children and construction workers wear the fabric when they want to be seen at night, and it’s even available as paint. With Tachi’s camera and projector setup, surgeons might apply a coat to a patient’s stomach so they could “see” the internal organs underneath (they’d need to use images from previous scans). They might even paint their gloves and arms so they’d have an unobstructed view. Likewise, pilots might be able to see through the cockpit deck to the ground below, making landings easier. Tachi’s team is currently collaborating with medical and aviation firms on products (he won’t discuss the specifics). The technology can also “realize your dreams,” he says. “How about projecting the outside landscape on the walls of a windowless room? You can have your own virtual window.” Soon it may be harder than ever to know what’s real and what isn’t.