Was that a ghost? No... it was an invisibility cloak

[Ele]

Remember the movie, Predator? That's how a metamaterial invisibility cloak may make you appear. Scientists in Germany are closer to making a three dimensional object invisible. In 2008 some scientists in California developed a new material which could make objects deflect light waves and so appear invisible, but only in two dimensions. That is, the object would only be hidden if you looked at straight ahead, but if you walked around the object it would reveal itself. The German scientists have improved on the metamaterial so it can actually wrap around an object and completely cloak it!

“You could imagine you have a flat gold mirror and you could put an object on that mirror,” Tolga Ergin from the Karlsruhe Institute explains. “An observer could immediately tell that there is a bump there and that there is an object hidden. Now we can put the three-dimensional carpet cloak on top of that bump so that the bump disappears – so the observer would again see a flat mirror.”

If you could try on the suit for a day, what activities would you indulge in to test it out? (cue: mischief, hehe)

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Invisibility cloaks closer to living up to their name
By Casey Johnston 24/04/2010 arstechnica.com

Metamaterials, which are used to produce the items that are termed "invisibility cloaks," have occasionally been targets of skepticism because they don't actually work in visible wavelengths. A paper published in Nature this week describes the structure of a new metamaterial with a negative refractive index that can misdirect light in most of the visible spectrum, up through blue light, bringing the cloaks a step closer to imparting actual invisibility.

The metamaterials that compose the invisibility cloaks work because they have a negative refractive index, which causes light entering them to bounce in an unusual way. Recently, scientists had found that the physical fabrication limits of their metamaterials were too close to the wavelengths of visible light, and they could only bend waves on the red end of the electromagnetic spectrum. The "invisibility cloak" name had been writing checks its functionality couldn't cash; to make visually undetectable material, scientists needed a new approach.

They found they were able to bend visible light by using a two-dimensional array of coaxial waveguides arranged in a hexagonal configuration. The waveguides were composed of two layers of silver sandwiching a gallium-phosphorus insulator; they could maintain a negative refractive index for light of wavelengths as short as 450-500 nanometers, corresponding to the color blue.

The literal invisibility cloak is stll incomplete—as it stands, the metamaterial described here would be able to bend away every color except violet, so anything "cloaked" would just be highlighted purple. Even if researchers do eventually conquer violet, an invisibility cloak might still be noticeableto the human eye. Still, the ability to bend shorter wavelengths brings scientists a step closer to a new way of beating the diffraction limit and creating superlenses that can see features even smaller than the wavelengths we use.

[Ele]

Well... I thought it was fasicnating that we are this step closer to having a three dimensional invisibility suit, and I hope these boffins can figure out how to bend away violet. I would like to go bodysurfing at a beach wearing one and film it. I would just look like a transparant shape mirroring the water. I wonder how water appears on it? Could make for some great performance art...

[Feck]

Being highlighted purple would be Cool

Totally invisible mmm lots of things spring to mind Vigilante ,wildlife photography (and or poaching) ,Messing with priests at Mass ,Making children believe in ghosts, Whispering into the popes ear

[Deep Sea Isopod]

Being highlighted purple would be Cool

Totally invisible mmm lots of things spring to mind Vigilante ,wildlife photography (and or poaching) ,Messing with priests at Mass ,Making children believe in ghosts, Whispering into the popes ear

Hiding in female changing rooms at the gym.

[Trolldor]

You know if we ever have a tangible invisibility cloak the military's going to be using it.

[Pappa]

You know if we ever have a tangible invisibility cloak the military's going to be using it.

What about an intangible invisibility cloak?

[Trolldor]

The military's using that now.

[PsychoSerenity]

Oooh exciting! would it be too silly to hope for some... pictures?

[Trolldor]

[PsychoSerenity]

Wow that's incredible! I can't see it at all!



Seriously though - are there any pictures that aren't photoshopped or from Harry Potter? It'd be interesting to see how well it works, even if it's making things purple.

[Ele]

Seriously though - are there any pictures that aren't photoshopped or from Harry Potter? It'd be interesting to see how well it works, even if it's making things purple.

I get the impression it would look something like Predator, but with some violet glitches in its present stage. I would really love to see how it looks under water. Maybe it would be even more "invisible" when reflecting water....? Perhaps one of the good science boffins here could explain for us how the negative refractive index thingymajig would work.

[Friday]

Dont know if they would ever make it perfect - but it would certainly be really, really, really good camo.

Best of all - its universal, so you wouldnt need to wear the unfashionable khaki greens again! Hell, you could choose whatever hip, non-combat colours you want!

[Trolldor]

Dont know if they would ever make it perfect - but it would certainly be really, really, really good camo.

Best of all - its universal, so you wouldnt need to wear the unfashionable khaki greens again! Hell, you could choose whatever hip, non-combat colours you want!

Until it failed on you, at which point wearing orange and hot pink probably isn't the best choice.