A real invisibility cloak is in our grasp

[Jonnymac]

Hi, all

I don't post often - bit of a lurker, but this really caught my attention - real Sci-Fi stuff.

CHICAGO (AFP) - Harry Potter fans take note: scientists have finally come up with a workable design for an invisibility cloak.

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Physicists figured out the complex mathematical equations for making objects invisible by bending light around them last year.

A group of engineers at Purdue University in Indiana have now used those calculations to design a relatively simple device that ought to be able to - one day soon - make objects as big as an airplane simply disappear.

The design calls for tiny metal needles to be fitted into a hairbrush-shaped cone at angles and lengths that would force light to pass around the cloak. This would make everything inside the cone appear to vanish because the light would no longer reflect off it.

"It looks pretty much like fiction, I do realize, but it's completely in agreement with the laws of physics," said lead researcher Vladimir Shalaev, a professor of electrical and computer engineering at Purdue.

"Ideally, if we make it real it would work exactly like Harry Potter's invisibility cloak," he said. "It's not going to be heavy because there's going to be very little metal in it."

The still-theoretical design will be published this month in the journal Nature Photonics.

Shaleav said he needs to secure funding to build the device and expects it would take two to three years to come up with a working prototype.

The major limitation is that the current design can only bend the light of a single wave-length at a time, and does not work with the entire frequency range of the visible spectrum.

"How to create a design that works for all colors of visible light at the same time will be a big technical challenge, but we believe it's possible," Shalaev said. "In principal it's doable."

Even blocking a single frequency can lead to useful applications, Shaleav said.

The cloak could shield soldiers from night-vision goggles which use only one wavelength of light. It could also be used to hide objects from "laser designators" used by the military to illuminate a target, he said.

Other researchers have managed to clock objects from the microwave range of the spectrum, which are much larger than the wavelengths of visible light.

This new design is the first for cloaking objects of any size in the range of light visible to humans.

It works by using tiny needles to alter the "index of refraction" around the cone.

Every material has its own refractive index which determines how light bends and slows down as it passes from that material into another. It's commonly described as the bent-stick-in-water effect, which occurs when a stick placed in a glass of water looks bent when seen from outside the glass.

Natural materials typically have a refractive index greater than one. But the tiny metal needles layered inside the cone work to gradually alter the index from zero at the inner surface of the cloak, to one at the outer surface of the cloak. This guides, or bends, light around the cloaked object.

The technology for making the tiny needles is already used to make nanotech devices. The needles in the theoretical design are about as wide as 10 nanometers, or billionths of a meter, and as long as hundreds of nanometers.

A single nanometer is roughly the size of 20 hydrogen atoms strung together

Source

[shuggee]

I want to see a photo.

[Dazza]

I want to see a photo.

[M'Lady]

I'm afraid I don't see the point of this technology...

[flagpole]

I'm afraid I don't see the point of this technology...

snigger.

[The Penguin]

snigger.

What? What? Where? Who said that? Come out and show yourself.

[Dazza]

What? What? Where? Who said that? Come out and show yourself.

Careful TP, she'll poke you in the eye and you'll have trouble seeing.

[The Penguin]

Careful TP, she'll poke you in the eye and you'll have trouble seeing.

Could be worse . . .

[Osbourne One-Nil]

I want to see a photo.

You can't because it's invisible.

I'm afraid I don't see the point of this technology...

It's to make people invisible.

[SP1986]

If its true it wouldnt necessarily be good, imagine what it could do in wars?

[The Penguin]

Why would it occur to anyone to use such a device for war when there are any number of wizard wheezes it could be better directed towards.

[Pickles]

Why don't they just employ David Copperfield?

And in a war situation, surely they could build a huge cloak to go over cities and hide them.

[tesaro]

Heres a picture of a cloaked 747 on a runway.

[SP1986]

Why would it occur to anyone to use such a device for war when there are any number of wizard wheezes it could be better directed towards.

Because the world, and some people in it are sick minded, you should know that by now surely with recent going on (ie corruption etc)? The fact is, if it can cloak a whole aircraft then it would be a formidable weapon for war situations.

[Soaring Hawk]

Trust me. This is not fantasy.

They spent years perfecting the technique on toilet roll holders. No-one with a Y chromosome saw a thing.

And I've been a cloak-wearing protege for years. Especially when I'm chained to the Aga cooking a huge Sunday lunch or at the sink contemplating the mountains of washing up.

[Mark Bayley]

If its true it wouldnt necessarily be good, imagine what it could do in wars?

Wouldn't they have thermal imaging camra's. Apart from wich how would they fire a gun through a the thing. They couldn't make ships or planes invisible becouse of radars. The only use i can think of is to scare people or sneek in and out of lessons :unsure:

[Osbourne One-Nil]

Mrs OON has clearly used one on all my birthday pressies.

[Mark Bayley]

Mrs OON has clearly used one on all my birthday pressies.

:unsure:

[Hiya]

Wouldn't they have thermal imaging camra's. Apart from wich how would they fire a gun through a the thing. They couldn't make ships or planes invisible becouse of radars. The only use i can think of is to scare people or sneek in and out of lessons :unsure:

Incorperate a layer of material to prevent IR radiation being emitted! Lateral thinking!

You don't need to fire a gun whilst covered, use them for manouver and ambush.

[Zachary]

Where did you find out about this? :unsure:

[OneOffDave]

How would you find where you'd left it?

[Osbourne One-Nil]

They come with those little devices for attaching on your keyring which beep when you whistle, but only the goodies would know the right note to whistle, so it stays secure.

[The Penguin]

Em, would this device also be waterproof? And retain its invisibility properties in the shower, for instance?

[Hiya]

Where did you find out about this?

There have been articles in most of the major science journals over the last few months.

http://news.nationalgeographic.com/news/20...ible-cloak.html

[Osbourne One-Nil]

There was also something about it in Penthouse last month, although they took an entirely different approach to the technology's use.