Two papers (count 'em, two!) in this week's issue of Science describe the possibility and theoretical method to construct cloaking devices. (No demo devices as of yet.) Imperial College London physicist Sir John Pendry and his colleagues describe an approach based on metamaterials that could bend electromagnetic radiation, including light around an object. (Link to paper abstract.) Meanwhile, Ulf Leonhardt of the University of St. Andrews, writes about using metamaterials in "a general recipe for the design of media that create perfect invisibility within the accuracy of geometrical optics." (Link to paper abstract.) From National Geographic News:
Invented six years ago, the man-made (metamaterials) are embedded with networks of exceptionally tiny metal wires and loops.
The structures refract, or bend, different types of electromagnetic radiation–such as radar, microwaves, or visible light–in ways natural substances can't.
"[Metamaterials] have the power to control light in an unprecedented way," said Sir John Pendry, a theoretical physicist at England's Imperial College London.
"They can actually keep it out of a volume of space, but they can do so without you noticing that there's been a local disturbance in the light…"
So far researchers have only developed metamaterials that divert radar and microwaves–rather than light waves, which are the key to invisibility.
While that's good news for Air Force generals who want to conceal warplanes, it's bad news for wannabe wizards hoping for a magic cloak.
Link to National Geographic News article, Link to BBC News report (Thanks, Paul Saffo!)
