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Invisibility cloak 'five years away'
Scientists have taken the first steps towards creating a Harry Potter-style cloak of invisibility.
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 obvious military applications have attracted support from the US Defence Advanced Research Projects Agency (Darpa), which funded the early research.
Already the scientists are a long way towards the easier goal of creating a cloak that can render objects invisible to radar or radio waves. Both have longer wavelengths than visible light, making them less challenging to work with.
"We are confident we can build a cloak that will work for radar within 18 months," said Prof Pendry, one of the authors of a research paper published today in the journal Science.
The key to the invisibility cloak is "metamaterial" - exotic composite material made using nanotechnology that can change the direction of electromagnetic radiation.
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.
"The hard job is to get the rays of light to pass in a smooth curve around the object," said Prof Pendry.
"You can't dump them just anywhere. They have to be deposited so that they're travelling in the same direction they started from. It is a tall order, but theoretically possible."
Metamaterials have already been demonstrated by Professor David Smith, from Duke University in Durham, North Carolina, one of the US scientists who contributed to the Science paper.
These materials can be made to interact with light or other electromagnetic waves in very precise ways.
"The cloak would act like you've opened a hole in space," said Prof Smith.
"All light or other electromagnetic waves are swept around the area, guided by the metamaterial to emerge on the other side as if they had passed through an empty volume of space."
As well as hiding objects, an invisibility cloak could have other uses, such as clearing away obstructions and eyesores.
Factory buildings or warehouses could be encased in invisibility material to prevent them blocking views of the unspoiled countryside.
source
Scientists have taken the first steps towards creating a Harry Potter-style cloak of invisibility.
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 obvious military applications have attracted support from the US Defence Advanced Research Projects Agency (Darpa), which funded the early research.
Already the scientists are a long way towards the easier goal of creating a cloak that can render objects invisible to radar or radio waves. Both have longer wavelengths than visible light, making them less challenging to work with.
"We are confident we can build a cloak that will work for radar within 18 months," said Prof Pendry, one of the authors of a research paper published today in the journal Science.
The key to the invisibility cloak is "metamaterial" - exotic composite material made using nanotechnology that can change the direction of electromagnetic radiation.
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.
"The hard job is to get the rays of light to pass in a smooth curve around the object," said Prof Pendry.
"You can't dump them just anywhere. They have to be deposited so that they're travelling in the same direction they started from. It is a tall order, but theoretically possible."
Metamaterials have already been demonstrated by Professor David Smith, from Duke University in Durham, North Carolina, one of the US scientists who contributed to the Science paper.
These materials can be made to interact with light or other electromagnetic waves in very precise ways.
"The cloak would act like you've opened a hole in space," said Prof Smith.
"All light or other electromagnetic waves are swept around the area, guided by the metamaterial to emerge on the other side as if they had passed through an empty volume of space."
As well as hiding objects, an invisibility cloak could have other uses, such as clearing away obstructions and eyesores.
Factory buildings or warehouses could be encased in invisibility material to prevent them blocking views of the unspoiled countryside.
source
