Published in Physics World, Apr 28 2011
An invisibility cloak that is less than five times bigger than the object it conceals has been unveiled by physicists in Denmark and the UK. They say that their device, which they built using semiconductor manufacturing techniques, offers the smallest cloak size relative to cloaked area to date.
First developed in 2006, invisibility cloaks can hide an object from view by bending light around it. The effect is similar to how a star’s immense gravity can warp space–time so that passing light is forced to take a curved path. In invisibility cloaks, however, the path of light is altered not by gravity, but by specially engineered variations in the refractive index of the devices. [...]
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