Scientists turn fiction into reality, create invisibility cloak

The concept of invisibility seems perfectly believable when we read about a fictional world filled with witches, wizards and centuries-old magic, but in the real world it is impossible to turn such fantasy into reality, especially invisibility.

But Harry Potter’s mischief-enabling cloak is now a reality, as scientists led by a team at Duke University have developed what they call an "invisibility cloak," by using a technology designed to make solid objects vanish from sight.

An invisibility cloak layout was produced in May by Professor Sir John Pendry, a physicist at Imperial College London. His associate scientists working with him in the US have put the idea into practice. In their first experiment, scientists had successfully cloaked a copper cylinder.

Scientists say their "invisibility cloak" is a primitive device that keeps objects out of the sight by bending electromagnetic waves so that they flow around the object like water around a rock. As none of the waves are reflected back at the observer, the object appears to be out of the sight.

The device, a set of concentric copper circles on fiberglass board, works on the principle that an object disappears if light rays striking on it are not reflected as usual, but forced to flow around it and carry on, as if it was not there.

David R. Smith, a professor of electrical and computer engineering at Duke University in North Carolina and an author of the paper published in the journal Science on Friday, described further that the system deflects electromagnetic waves of a specific frequency that strike it, without much of the scattering and absorption that make reflections and shadows.

To create the cloaks, scientists developed laboratory-made materials, "metamaterials", meticulously patterned thin metal sheets that can bend light in precisely the right way. "The material ends up being very complicated and not something you can make using materials that are lying around, like plastics or ceramics," Professor Smith said.

Scientists say their device works only with microwave radiation and only in two dimensions. Furthermore, it does not yet provide total invisibility, producing a small shadow that can be noticed.

Though, the cloak measures less than five inches across and only responds to radar waves, but scientists assert that within five years there might be devices puissant enough to make whole vehicles "vanish", including battleground tanks.

"It's not quite Harry Potter," Professor Smith said. "It's not exactly perfect - we can do better - but it demonstrates the mechanism, the way the waves swirl around the centre region where you want to conceal things," he said.

The possibility of invisibility would definitely fascinate the military, which will create objects that are invisible to radar or to shield equipment from cellphone signals.The invisibility would be ideal for hiding their tanks on the battle field.