Published August 15, 2008
Invisibility devices, long the realm of science fiction and fantasy, have moved closer after scientists engineered a material that can bend visible light around objects.
The breakthrough could lead to systems for rendering anything from people to large objects, such as tanks and ships, invisible to the eye — although this is still years off.
Researchers at the University of California at Berkeley, whose work is funded by the American military, have engineered materials that can control light's direction of travel. The world's two leading scientific journals, Science and Nature, are expected to report the results this week.
It follows earlier work at Imperial College London that achieved similar results with microwaves. Like light, these are a form of electromagnetic radiation but their longer wave-length makes them far easier to manipulate. Achieving the same effect with visible light is a big advance.
Underlying the work is the idea that bending visible light around an object will hide it.
Xiang Zhang, the leader of the researchers, said: "In the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock." An observer looking at the cloaked object would then see light from behind it — making it seem to disappear.