By Peter Weiss
First, a disclaimer: Invisibility cloaks like Harry Potter’s are nowhere near becoming reality. Nor has anyone unearthed proof that the infamous Philadelphia experiment—in which U.S. Navy scientists in 1943 supposedly made a destroyer and its crew vanish—really took place. Stygian crystals, said to confer invisibility in Star Wars films and books, remain figments of writers’ imaginations. And not one invisibility shield yet exists, not even a mouse-size one, as best anyone can tell.
The reality is this: Scientists have recently been doing some deep thinking about how light and matter interact. As a result, even some practical-minded physicists and engineers have embraced the notion that humankind’s long-held desire to make a person or an object invisible may no longer be just the stuff of fantasy.