One small step toward invisibility.

The ability to vanish has long been the stuff of fantasy, from disappearing Romulan warbirds on Star Trek to Harry Potter's invisibility cloak. Now, scientists have demonstrated a technology that could be a small step toward a "cloaking device." A set of concentric copper circles deflects electromagnetic waves so that they slide around a structure. Using this technology, scientists were able to cloak a copper cylinder. It's similar to a mirage, in which heat bends light waves and cloaks the road ahead. "We have built an artificial mirage that can hide something from would-be observers in any direction," says David Schurig, a research associate at Duke University in Durham, N.C. But scientists say that cloaking devices like the ones depicted in science fiction, while theoretically possible, are still a distant dream.