Metamaterial 'Space-Time Cloak' Conceals Not Just Objects, But Entire Events
Forget invisibility cloaks. Researchers at Imperial College London have demonstrated - on paper, anyhow - a metamaterial "space-time cloak" that can conceal entire events from view, making a viewer see one thing while something entirely different takes place behind the cloak. Paging DARPA. Just as metamaterial "invisibility cloaks" manipulate photons to conceal their subjects or otherwise change visual perception of an object, a space-time cloak would rely on light manipulation to achieve its aims. But unlike other metamaterials, which bend light around an object to render it invisible in certain wavelengths, the space-time material would accelerate and slow photons to create gaps in visual time. To borrow an analogy from one of the researchers on the project, think of the photons like steady traffic flowing down a freeway. You want to create space to cross the freeway, so you accelerate the traffic. Simultaneously, you slow all the traffic beyond a certain point...