Scientists see a future for invisibility devices

Harry Potter and his pals Ron and Hermione have been scooting undetected around Hogwarts for years beneath the invisibility cloak that Harry got from his murdered father, but now an international team of theoretical physicists suggests that muggles, or nonwizards, might someday make a cloak of their own.

Reporting last week in the journal Science, physicists J.B. Pendry of Imperial College London and David Smith and David Schurig of Duke University described a way to make high-tech "metamaterials" that can funnel light around an object and make it invisible.

Metamaterials, assemblages of small artificial bits of patterned metal films, can be engineered to bend almost any kind of electromagnetic energy. Schurig said that "probably this year" scientists will produce a metamaterial that can shield equipment from microwave radiation. However, protecting objects from visible light — creating an invisibility cloak — is "further out," he said in a telephone interview — "maybe 10 years."

Smith compared the process to a stream flowing around a stone — essentially creating a "hole" in the water, where anything can be hidden and remain unnoticed from the outside. "We have shown it can be done for almost any frequency," he said in a telephone interview. "Being able to build it is another story."

Schurig said the first invisibility devices would probably be rigid "shells" rather than supple cloaks, "but, in principle, cloaks would be possible."

Harry and his friends will still have the advantage, though, because while metamaterials would make you invisible, they would also isolate you from the outside world. You wouldn't be able to spy on anyone. Like a Romulan Bird of Prey (at least until "Star Trek: Nemesis"), you'll have to decloak before attacking.