New materials that can change the way light and other forms of radiation bend around an object may provide a way to make objects invisible.

Two separate teams of researchers have come up with theories on ways to use experimental ””metamaterials”” to cloak an object and hide it from visible light, infrared light, microwaves and perhaps even sonar probes researchers said yesterday.

Their work suggests that science-fiction portrayals of invisibility, such as the cloaking devices used to hide space ships in Star Trek, might be truly possible.

Harry Potter”s cloak or The Invisible Man of films and fiction might be a bit harder to emulate, however, because the materials must be used in a thick shell.

The concept begins with refraction — a quality of light in which the electromagnetic waves take the quickest, but not necessarily the shortest, route. This accounts for the illusion that a pencil immersed in a glass of water appears broken, for instance.

””Imagine a situation where a medium guides light around a hole in it,”” Physicist Ulf Leonhardt of Britain”s University of St.

Andrews, wrote in one of the reports, published in Friday”s issue of the journal Science.

The light rays end up behind the object as if they had traveled in a straight line.

””Any object placed in the hole would be hidden from sight. The medium would create the ultimate optical illusion: invisibility, Leonhardt wrote.

””Such devices may be possible. The method developed here can be also applied to escape detection by other electromagnetic waves or sound."

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