A Space-Time Cloak Is Much More Exciting Than An Invisibility CloakS

Do you find the idea of an honest-to-goodness cloak of invisibility intriguing? How about a cloak that obscures events in space-time? Science is making it happen.

the United Kingdom is obsessed with not being seen, and I blame Monty Python.

Earlier this month I posted about a team of researchers in Scotland that were using a special class of materials known as metamaterials to create a cloak that bent the visible spectrum of light, rendering objects or people covered in it invisible.

That apparently wasn't good enough for Professor Martin McCall and his team from Imperial College London. They won't be happy until they're able to obscure entire events from view.

Instead of simply bending light, the researchers' proposed space-time cloak would manipulate the speed at which light travels. Let's let the good professor and Physorg.com explain.

"Light normally slows down as it enters a material, but it is theoretically possible to manipulate the light rays so that some parts speed up and others slow down," says McCall, from the Department of Physics at Imperial College London. When light is 'opened up' in this way, rather than being curved in space, the leading half of the light speeds up and arrives before an event, whilst the trailing half is made to lag behind and arrives too late. The result is that for a brief period the event is not illuminated, and escapes detection. Once the concealed passage has been used, the cloak can then be 'closed' seamlessly.

The cloak would effective open up a corridor through which energy, matter, and information could travel without being detected. The example is given of a man walking down a corridor. One moment the man would appear at one end, and then they would vanish, reappearing at the other end.

While the chance of you or I ever witnessing one of these space-time to warp every day events is slim, the proposed device does have some rather interesting computer applications, particularly in regards to signal processing.

Alberto Favaro, who also worked on the project, explains: "Imagine computer data moving down a channel to be like a highway full of cars. You want to have a pedestrian crossing without interrupting the traffic, so you slow down the cars that haven't reached the crossing, while the cars that are at or beyond the crossing get sped up, which creates a gap in the middle for the pedestrian to cross. Meanwhile an observer down the road would only see a steady stream of traffic."

I think I'm slowly falling in love with metamaterials, and I owe it all to the daily Kotaku science posts.

Access the full study on the space-time cloak or "history editor" at IOPscience.


'Space-time cloak' to conceal events revealed in new study
[Physorg]