Scientists Take Step Towards Invisibility Cloak

From the International Tribune:

By John Schwartz The New York Times

Published: October 20, 2006

Invisibility has long been the stuff of fantasy, from Plato's story of the ring of Gyges to Harry Potter's mischief-enabling cloak. But scientists led by a team at Duke University have demonstrated a technology that could be a small step in the right misdirection.

The system, a set of concentric copper circles on fiberglass board, deflects electromagnetic waves of a specific frequency that strike it, without much of the scattering and absorption that make reflections and shadows.

A result is that the microwaves slide around the structure like water flowing around a smooth rock in a stream, said David Smith, a professor of electrical and computer engineering at Duke and an author of the paper published today in the journal Science.

The exact structure of the circles was described in an earlier paper by Sir John Pendry of Imperial College in London, who worked with the Duke group to see his theory etched into a working model by means of the process used to print circuit boards. In the recent paper, researchers said they had successfully cloaked a copper cylinder.

The findings were first reported in The Sun, a British newspaper. "Boffin Invents Invisibility Cloak," the headline stated, using the British slang for a research scientist.

Enthusiasts have already suggested that the technology may someday be useful for the military to create objects that are invisible to radar or to shield equipment from cellphone signals.

But Smith warned against getting ahead of the day's announcement and envisioning the disappearing Romulan warbirds of "Star Trek" on the horizon. The work "is really a scientific explanation," he said, adding, "Whether it's useful is always a question."

Creating a cloaking device in the visible spectrum would be vastly more complex, he said, since the device would have to warp all of the wavelengths of light. The chance of creating such a device is "dim," he said, but, "The theory doesn't prevent it from an electromagnetic point of view."

Businesses are already looking at possible applications, said Nathan Myhrvold, a former chief technology officer of the Microsoft Corporation whose company, Intellectual Ventures, explores the potential of new inventions.

"We hope it's got some commercial potential," Myhrvold said. "It could easily take years to figure out what the stuff is really good for from a practical, pragmatic standpoint. But, boy, it sure is really cool from a short-term standpoint."