Physicists routinely baffle reporters, but for once things went the other way. Alexander Gaeta was sitting in his Cornell University office in the fall of 2010 when a reporter called to ask his opinion of a strange new paper in the Journal of Optics: What did he think about the claim that it might be possible to create a time cloak, a device that would render events undetectable?
Gaeta was caught off guard. He was still grappling with the invisibility cloak, a wild idea that turned into reality in 2006, when physicists demonstrated that a class of synthetic materials could bend light completely around an object. (Think of water in a stream flowing around a rock.) Without light bouncing off the object, it would essentially disappear.
But creating a time cloak—something that could hide not just an object but an event—is even more ambitious. Rather than just rerouting the rays ...
