A team of American and British researchers has made a cloak of invisibility. Well, OK, it's not perfect. Yet. But it's a start, and it did a pretty good job of hiding a copper cylinder. In this experiment, the scientists used microwaves to try and detect the cylinder.
Like light and radar waves, microwaves bounce off objects making them visible and creating a shadow, though it has to be detected with instruments. If you can hide something from microwaves, you can hide it from radar — a possibility that will fascinate the military.
Cloaking differs from stealth technology, which doesn't make an aircraft invisible but reduces the cross-section available to radar, making it hard to track.
Cloaking simply passes the radar or other waves around the object as if it weren't there, like water flowing around a smooth rock in a stream.
The new work points the way for an improved version that could hide people and objects from visible light.