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, researchers said
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.
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
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,
Professor John Pendry, from Imperial College London, said that it may not
take long to develop an invisible fabric - assuming there is sufficient research
into the technology.
"If there is adequate funding, I'd have thought it would take in the order of
five years," he said.
"You could build a shed out of this material and drive a tank in there, or a
motor car, or hold a party inside it, and once you close the door everything it
contains would be completely invisible."
The key to the invisibility cloak is "metamaterial" - exotic composite
material made using nanotechnology that can change the direction of
Light waves would flow around an object hidden inside the metamaterial cloak
just as water flows virtually undisturbed around a smooth rock.
It would not simply block out light, or prevent its reflection, as in
conventional "stealth" technology. Whatever direction it is viewed from, the
light bending round the hidden object would make it appear to have vanished,
Metamaterials are composite structures that deliberately resemble nothing
found in nature. They are engineered to have unusual properties, such as the
ability to bend light in unique ways.
Like all physics, the invisibility idea requires a little imagination.
"Think of space as a woven cloth," Mr Schurig said in a telephone interview.
"Imagine making a hole in the cloth by inserting a pointed object between the
threads without tearing them."
The light, or microwaves, or radar would travel along the threads of the
cloth, ending up behind the object without having touched it.
"You just need the right set of material properties and you can guide light,"
Mr Schurig said, reports Advertiser Adelaide.