'Invisibility Cloak' Created Using Crystals

Zothecula writes "The quest to build a working 'invisibility cloak' generally focuses on the use of metamaterials – artificially engineered materials with a negative refractive index that have already been used to render microscopic objects invisible in specific wavelengths of light. Now, using naturally occurring crystals rather than metamaterials, two research teams working independently have demonstrated technology that can cloak larger objects in the broad range of wavelengths visible to the human eye. PDFs of the two similarly named research papers are available through arXiv.org."

Re:

[bobbinspenguin]

I've not seen the others

Re:

[ByOhTek]

The tend to show up once or twice a month.

Re:

[avronius]

Whoosh!

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[geegel]

Erm... No, I really don't.

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[Lazareth]

Total and COMPLETE negative refraction is impossible. Masking a selection of wavelengths is not. This is about fooling the human eye, not 'true' stealth tech which indeed violates the second law of thermodynamics.

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[Lumpy]

look for heat distortion in the air. they are not 100% invisible.

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[shia84]

I never really understood what is with this invisibility cloak obsession anyway. It's not like research like depicted in the article enables true invisibility... it only filters a comparatively small band, so no (radar+infrared+visible light) invisible planes, tanks etc. Also, no project so far has shown even the hint of the possibility to have angle independant cloaking. So that's no inivisible soldiers either, unless they don' t turn and all enemies are looking at them from one narrow perspective.

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[Decessus]

Would they be useful for small team reconnaissance missions perhaps a Marine sniper team or something similar?

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[noidentity]

Oh come on, it's not that bad; we only get them every other day.

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[jellomizer]

But all those geek Creds lost about how they had a pink object that was invisible.

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[nametaken]

Yeah seriously, is it Friday already? People seem to just keep reinventing the invisibility cloak, and then losing their prototype.

By now you'd think we'd be tripping on stacks of the damn things.

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[MikeDirnt69]

If an Invisible Cloak falls in the woods and no one around see it, does it make a sound?

Re:

[sortius_nod]

no idea why you got downranked, I laughed... just no mod points to unfuck your rank.

Won't do you any good

[Anonymous Coward]

If the refraction of the light prevents you from being seen, it will prevent you from seeing as well.

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[RussellSHarris]

Key phrase: as well.

I don't need to see all that well - a pinhole-sized camera would rival most of the lower-quality videos you'd find online, while still being relatively invisble. And the sound quality should be pretty good too...

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[omnichad]

If you have the pinhole camera, why do you need to be there too?

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[Culture20]

If the refraction of the light prevents you from being seen, it will prevent you from seeing as well.

Key phrase: as well.

I don't need to see all that well - a pinhole-sized camera would rival most of the lower-quality videos you'd find online, while still being relatively invisble. And the sound quality should be pretty good too...

"as well" == "also" == "too"

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[RussellSHarris]

"as well" == "also" == "too"

I knew that, of course, but I wasn't about to let it stop me from making my point.

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[Culture20]

...but who needs sight when you have hands?

Caution!

[mangu]

'Relatively' invisible may not be good enough. In this book [gutenberg.org] the main character was invisible except for his retinas. H. G. Wells had thought it out, if light didn't interact at all with his eyes he would be blind.

There was a moment when he was discovered because someone noticed those two tiny spots moving around.

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[RussellSHarris]

I'd be content enough to only see infrared light while I was "invisible" - as a bonus I hear it passes through lightweight cotton fabric pretty well.

Much better

[mangu]

Tile the outer wall of the women's changing room with calcite. That will render the wall invisible from the outside so you will be able to look in.

Re:

[SimonTheSoundMan]

See what?

I have actually seen this working the the University of Birmingham. It's impressive, but it's small.

A video I saw on my local BBC news the other week too: http://www.bbc.co.uk/news/science-environment-12338447 [bbc.co.uk]

One cheat code down

[Anonymous Coward]

Now to work on "God Mode"

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[MRe_nl]

One mission down.
Now find the Targoid mothership.

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[Maritz]

I'll have no clipping please. Sorted the invisibility with 'idbeholdi'

I dunno

[Dyinobal]

From reading the article I get mostly that it's done all with Mirrors and prisms essentially. Maybe someone else can point out what's so exciting about this?

Re:I dunno

[Shikaku]

I can't point out what's so exciting because I can't see it, duh!

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[Anonymous Coward]

From reading the article I get mostly that it's done all with Mirrors and prisms essentially.

It is actually slightly more sophisticated than that. They use the birefraction properties of calcite to bend the light rays in such a way that the exiting light has the exact same position and direction as if there were no wedge at the bottom. A simple mirror/prism assembly can not do this. It will either shift the beam or tilt it slightly.

The reason you see the wedge in the picture is because of lousy polishing. The tip of the wedge is not perfectly sharp.

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[thomst]

From reading the article I get mostly that it's done all with Mirrors and prisms essentially. Maybe someone else can point out what's so exciting about this?

My DOG, man! Can't you see the fantastic possibilities that will open up once they start adding SMOKE to those mirrors?

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[Darinbob]

Because they did it with only mirrors, no smoke was involved.

Invisible?

[symes]

Nothing to see here, move along...

To quote somebody smarter than me

[dkleinsc]

"I'll believe it when I see it."

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[Dolvid]

To quote somebody smarter than somebody smarter than you: "I'll believe it when I don't see it."

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[Issarlk]

My though exactly. The background is a convenient solid green.

This thread is worthless without pics

[jfengel]

Here's one:

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[Locke2005]

I see what you did there.

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[noidentity]

Then it's working.

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[paintballer1087]

I see what you did there.

I don't.

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[StikyPad]

Nice, that beats the shit out of using asterisks. Check it out, I copied and pasted your post from above and then put my password underneath:

hunter2 beyotches!!!

Hmmm

[Mister Whirly]

Invisibility cloak? BS - I'll believe it when I see it!

Stupid harry potter.

[RyuuzakiTetsuya]

screw the invisibility cloak! Give me Stealth Camouflage!

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[end15]

Screw the invisibility cloak, give me a girdle of giant strength!

How does this affect me?

[Locke2005]

Are we any closer to our goal of being able to sneak into women's locker rooms undetected?

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[OzPeter]

Are we any closer to our goal of being able to sneak into women's locker rooms undetected?

You already can .. all it requires is a minor sex change operation. Unless of course you already are female.

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[nitehawk214]

Are we any closer to our goal of being able to sneak into women's locker rooms undetected?

You already can .. all it requires is a minor sex change operation. Unless of course you already are female.

A: He is on slashdot, of course he is male.
B: Minor?

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[Locke2005]

I suspect I'd need to do something about my adam's apple, bald head, beard, chest and back hair as well. I even have hairy toes -- I suspect I'm part hobbit.

Life Imitates Art

[mdielmann]

This is so Inspector Gadget...

Magicians

[eepok]

Am I the only one who's thinking that this technology will most quickly adapted for stage magician acts?

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[GigsVT]

Probably. Magicians rely on much simpler effects than this. Most magic tricks have stupidly simple gimmicks.

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[amRadioHed]

True. In most cases redirecting people's attention is easier then photons.

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[eepok]

Well, some magic tricks are stupidly simple, yes. But others are extremely intricate and involve great deals of engineering and foresight. I'll use this as a simple example: http://www.youtube.com/watch?v=Ewef620ptj4 [youtube.com]

Given the money involved in big acts, I still wouldn't be surprised.

"CRYSTALS were integral!"

[Sparks23]

Does anyone else think of "Doctor Dinosaur" from Atomic Robo when reading this article?

http://www.nuklearpower.com/2009/07/24/free-comic-book-day-2009/ [nuklearpower.com]

Crystals of Dihydrogen monoxide

[rossdee]

Around here at this time of year naturally occuring crystals can cause objects to disappear., especially in high winds. In some cases even after the wind has subsided, things can remain hidden by being covered with a layer of these 6 sided crystals. There are 2 solutions, wait until the temperature increases and the crystals melt, or to use a shovel....

magic

[buback]

This is the same type of 'invisibility' preformed by magicians: i.e. mirrors.

Did somebody actually get a grant for this work?

Hmmmmm

[senorpoco]

Didn't David Copperfield make an elephant disappear the same way?

Disinformation?

[grikdog]

My initial reaction was Bunk! Disclosing the details of a technology so obviously useful to DoD would border on treason. There seems to be room to speculate the PR is disinformation.

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[geekoid]

You sir, are an idiot.

I don't know what world you think you live in, but the DoD doesn't go around imprisoning people for treason because they talk about something they invent. Unless they are under contract not to do so, and even then it wouldn't be treason.

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[grikdog]

"You sir, are an idiot."

It's possible. Thanks for pointing.

Maybe I'm missing something, but I think

[degeneratemonkey]

this isn't an invisibility cloak; it's high school physics.

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[maxwell demon]

The high school physics isn't missing. It's only hidden by an invisibility cloak.

calm down, everyone, it's just calcite...

[Hakubi_Washu]

No, really, once you get over that fact that calcite [wikipedia.org] has been known for its double refraction property for literally hundreds of years, and every child ever to get its hands on a lump of it trying to make it show weird shit, you'll realize that these people have figured out how to make stuff disappear when you look at it from exactly the right angle... Yawn. The calcite remains visible, obviously, BTW.

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[sonicattack]

Of course, this is not the same as Calcic Image Misplacement, another neat feature of calcium:

(skip to 2:45)
http://www.youtube.com/watch?v=oRL9IVvuNl8 [youtube.com]

That was incredibly unimpressive

[joeyblades]

OK. I guess that's one way of defining invisible.

So I can't see the pink material... I can still see the wedge of reflective material covering it. By this definition, I could throw a blanket over it and - 'poof' - it's invisible...

Re:

[ShiftyOne]

A blanket wont work. It has to be reflective and distort the image a little. Try a mirror from the 1700's.

Prior art !

[alexhs]

I could throw a blanket over it and - 'poof' - it's invisible...

But there are two thousand years of prior art on that technology...
Here [amotherinisrael.com], invisible women.

Re:

[lewiscr]

Once you paint it pink, just set up a SEP field.

I, for one, would like to..

[140Mandak262Jamuna]

I, for one, would like to welcome our over lords, but I can't see them. So they must be wearing this invisibility crystals!

This is AWESOME!

[RapmasterT]

a real invisibility cloak..and all it took was redefining the terms "invisibility", and "cloak". Hell if I knew it was that easy, I'd have invented one years ago.

Only one thing to add...

[ItsJustAPseudonym]

"I solemly swear I am up to no good."

My Time Machine

[degeneratemonkey]

Guys, GUYS. I invented a time machine. It's an ingenious device that can be programmed to generate loud, audible signals at a specific point in time. All you have to do is program the device with a time set in the future, and then fall asleep. When you wake up - presumably via aural stimulation from my invention - you will be in the FUTURE!

Suck it, Einstein.

not just crystals

[Filip22012005]

150 crystals AND 150 gas.

METH!

[DarthVain]

Yes invisibility crystals... Excellent!