The Guardian reports, "Authors Graeme Milton of Utah University and Nicolae-Alexandru Nicorovici of the Sydney University of Technology reveal how objects placed close to a material called a superlens appear to vanish.

 

"Such a device would be made of materials having negative refractive indices

 

"Instead of having a positive refractive index — which makes light bend as it passes through a prism or water — the materials have a negative refractive index, which effectively makes light travel backwards. It's light, but not as we know it."

 

Sir John Pendry, a theoretical physicist at Imperial College London who invented superlenses, told the Guardian: "Effectively, they are making a piece of space seem to disappear, at least as far as light is concerned. The secret is having the cloak itself be invisible, and if you can do that cheaply and efficiently and it doesn't need to be metres thick, it would be extremely valuable for stealth. Even if you could cloak a single frequency, it would be very useful. The military is extremely interested in this."

 

However, before you get too excited the authors note the calculations show that while the device could be used to obscure almost any object, it works only over a short range of wavelengths, so if used to hide objects from human vision, they might only partially disappear.