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'Invisibility Cloak' Created Using Crystals

Soulskill posted more than 3 years ago | from the keep-this-discovery-away-from-the-klingons dept.

Science 98

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."

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98 comments

Another day... (0)

Anonymous Coward | more than 3 years ago | (#35104564)

...Another invisibility cloak article on Slashdot.

Re:Another day... (3, Funny)

bobbinspenguin (1988368) | more than 3 years ago | (#35104596)

I've not seen the others

Re:Another day... (1)

ByOhTek (1181381) | more than 3 years ago | (#35104828)

The tend to show up once or twice a month.

Yet no one has refuted this article (0)

Anonymous Coward | more than 3 years ago | (#35105176)

Negative index of refraction violates the second law of thermodynamics:

http://www.opticsinfobase.org/abstract.cfm?uri=oe-16-23-19152 [opticsinfobase.org]

Re:Yet no one has refuted this article (2)

Lazareth (1756336) | more than 3 years ago | (#35105642)

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.

Re:Another day... (2)

shia84 (1985626) | more than 3 years ago | (#35106166)

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.

Re:Another day... (1)

Decessus (835669) | more than 3 years ago | (#35109588)

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

Re:Another day... (1)

nametaken (610866) | more than 3 years ago | (#35109524)

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.

This is great, but.. (0)

Anonymous Coward | more than 3 years ago | (#35104582)

When can I wear this into the women's changing room?

Won't do you any good (1)

Anonymous Coward | more than 3 years ago | (#35104648)

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

Re:Won't do you any good (1)

RussellSHarris (1385323) | more than 3 years ago | (#35105056)

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...

Re:Won't do you any good (1)

Culture20 (968837) | more than 3 years ago | (#35105242)

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"

Re:Won't do you any good (0)

Anonymous Coward | more than 3 years ago | (#35105564)

RusselSHarris is right.

A tiny imperfection in the invisibility would be enough to let you see clearly. Your pupils are a very small part of your total surface area.

(Damn it! Would I really stoop this low?)

Caution! (1)

mangu (126918) | more than 3 years ago | (#35106520)

'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.

Re:Caution! (1)

RussellSHarris (1385323) | more than 3 years ago | (#35106626)

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 (1)

mangu (126918) | more than 3 years ago | (#35104946)

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.

right... (0)

Anonymous Coward | more than 3 years ago | (#35104592)

"for the first time, the cloaking area is rendered at a size that is big enough for the observer to ‘see’ the invisible object with the naked eye"

If you can see it that means it's NOT working.

Calcite? Really? (0)

Anonymous Coward | more than 3 years ago | (#35104612)

I had a 3"-on-a-side parallelepiped of this stuff when I was four. Now they're telling me it can be used to make things invisible, and they're just now figuring it out? Wacky.

One cheat code down (2, Funny)

Anonymous Coward | more than 3 years ago | (#35104620)

Now to work on "God Mode"

I dunno (3, Insightful)

Dyinobal (1427207) | more than 3 years ago | (#35104626)

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 (3, Informative)

Anonymous Coward | more than 3 years ago | (#35105218)

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.

Re:I dunno (1)

thomst (1640045) | more than 3 years ago | (#35105352)

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?

Re:I dunno (0)

Anonymous Coward | more than 3 years ago | (#35105538)

An S.E.P or 'Somebody Else's Problem field' is a cheap, easy, and staggeringly useful way of safely protecting something from unwanted eyes.

Not convinced. (0)

Anonymous Coward | more than 3 years ago | (#35104660)

Does it work when the background isn't a solid color?

Hold on (0)

Anonymous Coward | more than 3 years ago | (#35104724)

Hold on, I almost forgot to insert the crystals.

This thread is worthless without pics (4, Funny)

jfengel (409917) | more than 3 years ago | (#35104766)

Here's one:

Re:This thread is worthless without pics (1)

Locke2005 (849178) | more than 3 years ago | (#35104800)

I see what you did there.

Re:This thread is worthless without pics (1)

StikyPad (445176) | more than 3 years ago | (#35108424)

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!!!

Stupid harry potter. (3, Funny)

RyuuzakiTetsuya (195424) | more than 3 years ago | (#35104780)

screw the invisibility cloak! Give me Stealth Camouflage!

Did you know that if you put a crystal glass into (0)

Anonymous Coward | more than 3 years ago | (#35109724)

a jar of alcohol, it becomes invisible? I saw this in the Crystal Skull of Doom (it's not just some Indiana Jones thing only) documentary at topdocumentaryfilms.com which shows it being done, pretty cool too. It's just about up there with watching a "super-liquid" and how it behaves, imo at least, and at a fraction of the cost! And, no wise-asses - this isn't about drinking fucking booze either, for those of you about to make some snide crack about it because you've tipped 1/2 a case of the magical liquids with it being Saturday nite and all.

How does this affect me? (2)

Locke2005 (849178) | more than 3 years ago | (#35104786)

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

Re:How does this affect me? (1)

OzPeter (195038) | more than 3 years ago | (#35104874)

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.

Re:How does this affect me? (2)

nitehawk214 (222219) | more than 3 years ago | (#35107046)

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?

Re:How does this affect me? (1)

Locke2005 (849178) | more than 3 years ago | (#35109472)

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.

Magicians (1)

eepok (545733) | more than 3 years ago | (#35104808)

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

Re:Magicians (2)

GigsVT (208848) | more than 3 years ago | (#35105292)

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

Re:Magicians (2)

eepok (545733) | more than 3 years ago | (#35105748)

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 of Dihydrogen monoxide (3, Insightful)

rossdee (243626) | more than 3 years ago | (#35104832)

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....

Re:Crystals of Dihydrogen monoxide (0)

SnarfQuest (469614) | more than 3 years ago | (#35106114)

You can't use DHMO!!! It's been declared illegal in several states!! That stuff have been found in CANCER cells!! Hundres of people die of DHMO overdose every year!!! Did I include enough exclamation points yet!!!!

magic (1)

buback (144189) | more than 3 years ago | (#35104894)

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

Did somebody actually get a grant for this work?

Re:magic (0)

Anonymous Coward | more than 3 years ago | (#35104966)

Probably, not like the optics of calcite weren't figured out over a hundred years ago. But we forget sometimes.

Another day, anther invisibility cloak story (0)

Anonymous Coward | more than 3 years ago | (#35104896)

One day, when they finally crack this technology, we will miss the constant false alarms on /.

Disinformation? (1)

grikdog (697841) | more than 3 years ago | (#35104948)

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.

Re:Disinformation? (1)

geekoid (135745) | more than 3 years ago | (#35105068)

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.

Re:Disinformation? (0)

Anonymous Coward | more than 3 years ago | (#35105350)

Also the US military pretty much does all it's fighting at night when the ability to hide from the unaided eye isn't all that uncommon. So you know... limited practical applications for the DoD.

Re:Disinformation? (0)

Anonymous Coward | more than 3 years ago | (#35107008)

Or if the item that a person invents even remotely has the potential to rub shoulders with anything the DOD considers important.

Re:Disinformation? (0)

Anonymous Coward | more than 3 years ago | (#35107320)

not to mention that hiding small objects with calcite crystals (when the crystals are still visible, and it only works with polarized light) is hardly a matter of national security!

calm down, everyone, it's just calcite... (1)

Hakubi_Washu (594267) | more than 3 years ago | (#35104984)

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.

That was incredibly unimpressive (2)

joeyblades (785896) | more than 3 years ago | (#35105060)

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:That was incredibly unimpressive (1)

ShiftyOne (1594705) | more than 3 years ago | (#35105372)

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

Prior art ! (2)

alexhs (877055) | more than 3 years ago | (#35106296)

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.

I, for one, would like to.. (1)

140Mandak262Jamuna (970587) | more than 3 years ago | (#35105158)

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

Pshaw (0)

Anonymous Coward | more than 3 years ago | (#35105664)

I'll believe it when I see it.

This is AWESOME! (1)

RapmasterT (787426) | more than 3 years ago | (#35105830)

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.

Already done (0)

Anonymous Coward | more than 3 years ago | (#35106284)

Didn't Erik the Viking do this with a simple bit of cloth?

Nothing new to see here.

My Time Machine (1)

degeneratemonkey (1405019) | more than 3 years ago | (#35107138)

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.

enough with the stupid cloaking stories. (0)

Anonymous Coward | more than 3 years ago | (#35107560)

Attention Slashdot:

Please stop posting these stupid damn stories. The first time was interesting, but 50 stories later I do not care if some dude can surround a ping pong ball with crystals/copper tubes/gremlins etc and make it invisible at 2.4506 Ghz in a flat plane.

Can I has? (0)

Anonymous Coward | more than 3 years ago | (#35108782)

Can I has Prism Tanks?

ONE THING DOWN two more to go (0)

Anonymous Coward | more than 3 years ago | (#35147110)

Now all we need is the power wand, and the stone who magically brings people back to life

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