A Step Towards an Invisibility Cloak

An anonymous reader alerts us to work out of Purdue University in Indiana, where researchers have produced a design for a method of cloaking objects of any shape and size at a single wavelength of visible light. The math for such an invisibility effect was worked out last year at Duke and in the UK, but the new work, to be published in Nature Photonics this month, is the first practical design. The lead researcher, Vladimir Shalaev, notes that even though the current design works only at a single wavelength, and so would not convey true invisibility, it could still be useful — against, for example, night-vision goggles or laser target designators. Shalaev calls the technical challenge of producing an all-wavelengths cloak "doable in principle."

Comments

In future...

[Anonymous Coward]

After mass production and commoditization, we will have invisibility T-shirts, invisibility sandals, and invisibility shorts.

Re:In future...

[tsajeff]

Ahh yes, the Emperor's new clothing line.

Re:In future...

[Anonymous Coward]

I, for one, welcome our invisible overlords! sorry, couldn't resist.

Re:In future...

[Anonymous Coward]

They've been here for years, you just noticed?

Re:In future...

[EnsilZah]

Surely, you mean Empress Hilton's new clothing line.

Re:In future...

[Anonymous Coward]

It seems to me that it would be a whole lot easier for someone to slap an S.E.P. field over everything...

Error Message

[FooAtWFU]

Never has this notice been more appropriate:

Nothing for you to see here. Please move along.

Re:Error Message

[aldo.gs]

Nothing for you to see in this wavelength. Please select another one.

Re:Error Message

[morcego]

Gives a whole new meaning to the phrase "just because I'm paranoid, doesn't mean no one is watching me", hum ?

Invisible to lasers, anyway.

[AJWM]

One wavelength hardly invisibility makes, but as the blurb suggests, it renders the target invisible to laser designators. Wonder how much power it can handle, would it be an effective shield against weapons-grade lasers?

Re:Invisible to lasers, anyway.

[Opportunist]

Weapons-grade lasers (i.e. lasers that do damage themselves) are with todays technology not really an issue. To create damage comparable to conventional methods of kaboom, you'd have to haul around a LOT more material and those pieces also tend to be a LOT more expensive. War is a cost/gain game, so don't expect to see any laser weapons too soon on the battlefields of the world.

What this aims at is laser targeting systems. Those lasers carry hardly enough firepower to cause any damage (ok, should you look RIGHT into them, maybe you might have some problem), but they point out the target to a laser guided weapon. And, well, you can't hit what you can't see (unless you decide to fire a spray of those kickass expensive laser guided weapons, which has not really a good cost/gain relation).

Re:Invisible to lasers, anyway.

[The Orange Mage]

Well, I guess this means we now have an effective anti-shark defense system...

Re:Invisible to lasers, anyway.

[Kandenshi]

I'm curious about something though...
I have absolutely no experience/knowledge of these laser targetters, but how much more expensive would it be to be able to use different wavelengths of light?

1. Try wavelength X: Oh darn, they're protecting against that with a shiny cloaking device, so...
2. Try wavelength Y: Profit!!!/explosions

The bomb or whathaveyou is searching for a very specific wavelength(X) right? But still doesn't seem like it should be impossible to program it to cycle through 2-3 wavelengths(X->Y->Z) until it finds your dot to lock onto.

Still, it's a neat toy they're working on. I wouldn't mind one once they build one that's less selective.

Re:Invisible to lasers, anyway.

[Opportunist]

I'm no expert for military grade lasers myself, but as far as I know, you need different media for different wavelengths. I.e. you'd have to mount one laser per wavelenth you want to try.

Re:Invisible to lasers, anyway.

[cyphercell]

I remember watching Black Hawk Down, and noticing that this troop (a motley crew of special forces) had the benefit of night vision effectively throughout the movie. When watching it I thoroughly believed that this was an advantage that made them successful in surviving the event. Imagine to armies fighting with night vision while one side has their special forces being cloaked.

Re:Invisible to lasers, anyway.

[mgv]

One wavelength hardly invisibility makes, but as the blurb suggests, it renders the target invisible to laser designators.

Invisible to laser speed checks would have some non military applications.

Michael

Re:Invisible to lasers, anyway.

[Columcille]

"Weapons-grade lasers (i.e. lasers that do damage themselves) are with todays technology not really an issue. To create damage comparable to conventional methods of kaboom, you'd have to haul around a LOT more material and those pieces also tend to be a LOT more expensive. War is a cost/gain game, so don't expect to see any laser weapons too soon on the battlefields of the world."

I didn't RTFA (hey, this is slashdot) but from the summary it sounds like a truly effective cloak of this sort is still some time away. A truly effective laser weapon is also still some time away. But it sounds like each of those will eventually make an appearance. Might not be a bad idea to consider laser weapons an issue so that when they do make an appearance we just might have something that can protect from them. I assume this is what military R&D is all about, come up with ways to defeat not-yet-existing systems so that when they exist we won't have to play catch-up.

Re:Invisible to lasers, anyway.

[YGingras]

Except that night vision devices aren't restricted to a single wavelength. Night goggles only amplify the light in the whole spectrum. The whole thing, not a single wavelength. The output is converted to monochrome to stimulate the more sensitive rod cells. By limiting color output the pupil stays more dilated and can gather more light. Its the same thing with astronomical telescopes. You read your maps with a red light and you get eyes pieces with exit pupil matching your night time pupil diameter.

Re:Invisible to lasers, anyway.

[Hal_Porter]

The S1A1 remote controlled great white shark has a secondary offensive capability based on 1) rows of sharp teeth and 2) neural implant boosted hunger, all guided by a keen sense of smell. Obviously, we planned for Chinese frogmen in invisibility suits.

This is all classified info BTW, please kill yourself after reading it, unless you happen to have SPECOPS/JAWS clearance.

Re:Invisible to lasers, anyway.

[ozydingo]

Even if night vision did work on detecting a single frequency, it wouldn't be a robust viable solution. Simply change the wavelength your night vision operates on, and the cloaking devices become useless. For this reason this technology as it stands currently is really not a viable solution for any military application as long as your opponents know anything about it (better hope they don't read Slashdot!)

Don't get me wrong, I think it's still cool and a good first step, just not with any militarily robust applications.

Re:Invisible to lasers, anyway.

[cyphercell]

So if the cloaking worked out to say 95% then night vision goggles could probably be used as a countermeasure? If so, how well do you think it might work (I'm guessing 100%)?

Re:Invisible to lasers, anyway.

[iamacat]

You are forgetting the fact that, unlike kaboom, laser travels instantly (unless you try to shoot Martians) and precisely. This makes them better suited for shooting down airplanes and cruise missiles. There is also an option of using a smaller laser to blind the pilot.

Re:Invisible to lasers, anyway.

[rtb61]

The cloaking device is most likely just a spectrum shifting coating. Catch is, a dirty tank, would be a dead tank.

Re:Invisible to lasers, anyway.

[Anonymous Coward]

But this technology would be awesome blocking laser light shows at Yanni concerts. Wait.. no.. Michael Bolton.

Although laser designator and awesome firepower would also be an acceptable way of dealing with these unentertainers.

Re:Invisible to lasers, anyway.

[ShooterNeo]

Well, yes, that is true for most convential lasers. Usually, the light emitted is a property of what elements you dope the lasing medium with (for solid state lasers) or what gases you used (for well, gas lasers)

However, if this horribly complex and expensive sound cloaking technology (against just 1 wavelength) ever become a threat, it would be trivial to upgrade the military lasers to a tunable one. There are numerous ways, including using free electron lasers which can be tuned to a wide range of wavelengths at will. Or...other ways. Really, I don't see it being a problem, the researchers saying it could be "useful" are just be sensationalistic. Or perhaps they want military funding, which in my opinion is a waste because it seems incredibly unlikely that nanoscale invisibility armor will ever be practical.

(well, it might be SOMEDAY, but I suspect that era would be around the same era when machines do all the fighting, and we have different considerations.

Re:Invisible to lasers, anyway.

[hazee]

One strategy might be to only turn on the device after the bomb or whatever is on its way.

If you just switched it on at the last moment and then moved your tank, that might work.

You'd be given advance notice that something was inbound by the fact that you were being illuminated in the first place.

Re:Invisible to lasers, anyway.

[Anonymous Coward]

Night vision devices are indeed restricted to a single wavelength. They cannot output color.
The intermediate amplification stages involve production of an electron for every photon striking the cathode plate. Later the multiplied electrons strike a phosphor screen to produce the image you see. The phosphor throws off visible photons in one narrow wavelength. The phosphor chosen invariably has an output peak of around 520nm- medium green- chosen due to its place on the human eye's sensitivity peak.
It is perfectly feasible to create a night vision device with red, blue, orange, etc output. Color output is not possible. As an aside, an infrared-lit scene has no color to be captured.
Regarding your latter sentences, limiting color output in such a way as you mention has no affect on pupil dilation.
It is arguable that the longer wavelength (and thus lower energy) of red light might degrade the function of rhodopsin more slowly, but this effect is certainly not present with green light.

Re:Invisible to lasers, anyway.

[zCyl]

Night vision devices are indeed restricted to a single wavelength. They cannot output color.

It's not a question of output, it's a question of input, since presumably the invisible-cloak-wearer is outside of the night vision goggles. And they input many wavelengths.

Re:Invisible to lasers, anyway.

[Opportunist]

Well, the tactic of "last moment" works for the attacker too. The AGM-114 can be used that way. Fired indirectly without a target, it first of all climbs to altitude, then starts diving down. You can start the painting fairly late, usually too late for a human operator to react, activate defensive devices and evade it.

Re:Invisible to lasers, anyway.

[Opportunist]

I can reassure you that military R&D is just like civil R&D: If there's no immediate application, your chance for funding is low.

Re:Invisible to lasers, anyway.

[Plutonite]

Yes, but infra-red sensors (which are one kind of night vision devices) typical use a tight range of wavelengths and thus could possibly be fooled or at least made inefficient. I do not know the extent of usage by the military in combat, but they tend to be useful in situations where you want to know if somebody is inside a room..etc before entering, because IR can penetrate thin barriers (doors..etc). As for air/space surveilance of ground activity, IR is far more important than light amplification in detecting enemy forces/missile silos from above. This is because equipment gives off heat even if it is dark/concealed.

I have not RTFA and do not know what "one wavelength" means.

Re:Invisible to lasers, anyway.

[Opportunist]

Lasers also have a very big problem: No indirect firing, no ballistic arc. I.e. you want to see your target, which in turn means your target can see you. Even though lasers travel instantly, large lasers with a few megawatt of power need horribly long to charge (or, in case of gas emission lasers, are horribly expensive to fire and also quite hazardous to be near, i.e. only suited for ground based sites that can be left unmanned). Some branch of the US military (forgot which one) actually had a project running with Israel that was aimed exactly at that, shooting down cruise missiles. The project was abandoned in the late 90s because of the cost (a shot of that laser blaster costed a few 1000 bucks), the hazard (with every shot you create a lot of very poisonous gas) and the fact that transport has to be ground based (even a Hercules can't lift it).

Especially that last part doesn't fit into the doctrine of high mobility of the US military. Not to mention that there are less expensive and more reliable means of getting rid of missiles.

Re:Invisible to lasers, anyway.

[IX SICK ECHO XI]

I'm in the armed forces, and we use NVG's( you call them Night vision goggles), there are no set wave lengths, the NVG'S either run passive which is the normal green night vision you see and infrared, which is intensified for a brighter image, given those different modes I assume have different wavelengths, but I wouldn't know the scientific terminology behind either.

Re:Invisible to lasers, anyway.

[minirock000]

that was very descriptive about night goggles. but they do also have an infared emitter for dark nights or places with no ambient light. i dont know if its possible to blind these with something like this, but with the ir emmiter on, its like have a flashlight on, attached to your face, anyone else with nv on can see you as such. my info my be a little dated, the last time i used "nods" they were the ANPVS-7 model. with regards to laser range finders (lrf) the one on the M1 tank is considered a direct fire weapon. as a gunner for several years, if i could not get a lock or a good read on a target, i would just aim at the ground in front of the target to get the range. so i dont think blocking the laser in this case would be beneficial.

Re:Invisible to lasers, anyway.

[Dr Damage I]

I doubt it would do anything to affect light intensification gear but it would most likely significantly degrade the usefulness of infra red equipment.

Re:Invisible to lasers, anyway.

[Anonymous Coward]

You say 'military applications' when you want to get funding for fairly basic research from DoD or DoE.

'Weapons Grade Lasers' Pah, too much time playing Half Life

Re:Invisible to lasers, anyway.

[iamacat]

Especially that last part doesn't fit into the doctrine of high mobility of the US military. Not to mention that there are less expensive and more reliable means of getting rid of missiles.

For example? I hear Patriot Intercepter missiles and space umbrella program didn't ever shoot anything down except under test conditions. If people are shooting nukes at you, maybe those very poisonous gases and expenses are not that bad after all.

Re:Invisible to lasers, anyway.

[nachtkap]

Has anyone ever tried to find someone thats not moving and wearing BDU's (camouflage uniform) in a forest ? its not all that easy even if u know their are approx. location and they are not really trying to hide. Thats with good light conditions, now imagine someone wearing camouflage with patches that shield against different common wavelength in your environment (desert and forest BDU's).

Also I imagine if u see 1/4 of the normal surface area of a tank it wouldn't look like a tank at all anymore, at least in low light conditions.

I'd think there would be also be applications for counter measures (the radar reflecting stuff). Imagine u could only see Grey, Blue and Brown and u are looking at a Grey, Blue and Brown Zebra behind a Blue and Brown curtain. I would think humans would get confused but can u imagine a missile thats trying to hit the best target it finds under those conditions.

Re:Invisible to lasers, anyway.

[YGingras]

Serious applications don't use an emitter. When you shine a large spotlight on an area, IR or not, you tell everyone where you are. But even with an IR spotlight, you are not within a single wave length. An IR spotlight it little more than an incandescent light that shines its peak in IR, with possibly a filter to block the visible emission since you'll emit some if you want a reasonable output. You get the whole continuum. I have not idea how the technology could be used to block night vision and the article is short on details.

Re:Invisible to lasers, anyway.

[Torvaun]

Less worry about laser range finders, more worry about guided missiles. On airborne things, like fighters or bombers, there's really no nearby mass to aim at if you can't get a return off the plane itself. From the other side, if these can be made cheap, why not put them on missiles to prevent AM systems from shooting them down?

Re:Invisible to lasers, anyway.

[YGingras]

You describe an optic only amplifier while I had a CCD-base one in mind. But, as someone else posted, the color range limitation was essentially with the output and had little to do with the input. But I'm curious, did everyone moved to CCD or is the optic amplifier still used? What would be the adventage? Less parts that would break?

Re:Invisible to lasers, anyway.

[imkonen]

I doubt this cloaking device is an issue for NVG's: You might only see one color when you look into the NVG, but that's just because that's the wavelength of the output resulting from the phosphor screen. I can't imagine any reason why the acceptable input wavelengths for NVG's would be limited to a single wavelength (or more realistically a narrow wavelength range): it's generally harder to make devices sensitive to a narrow range of wavelengths, and there'd be little to no advantage in doing so...you wouldn't need a fancy cloaking device to hide an object from NVGs at that point, just paint of any other color. Same thing with the IR vision: blackbody radiation from warm bodies is broadband, and so are IR detectors. I'm not in the military, but I've worked with IR lasers before, and we used what we called IR viewers, but sure seemed like they could have been rifle scopes, to see what we were doing. They could see IR from 800nm to 2000nm without any need to change modes or input filters.

Re:Invisible to lasers, anyway.

[Skrynkelberg]

Are there really infra-red equipment (except lasers, which are already covered in another post) that depends on just a single wavelength? Cameras that can "see" infra-red radiation (e.g. heat) operate in an entire section of the infra-red spectrum. You know how images from infra-red cameras tend to show red for hot, blue for cold, etc? Well that's different shades of infra-red for you (translated to the visible spectrum so that we can see the difference).

Re:Invisible to lasers, anyway.

[hachete]

tank cleaners would be at a premium then

Re:Invisible to lasers, anyway.

[Marcos Eliziario]

Of course they read slashdot. But don't be afraid, because, as every other slashdot reader, it's every unlikely they ever read TFA.

Re:Invisible to lasers, anyway.

[Opportunist]

And who might that be who's shooting nukes at me? The Soviet Union doesn't exist anymore and ... well, knowing some of their rocket systems I wouldn't be too scared. China has the potential, but is too busy getting cozy with the world trade system to want that relations to shatter. And beyond that the air gets thin, not because some country doesn't have "the" bomb (or claims to have it, or whatever), but having the bomb means jack if you can't deliver it.

And UPS doesn't. I checked.

So personally my fear of nukes has dwindled somewhat during that last 20 years.

Re:Invisible to lasers, anyway.

[kalirion]

So you can't just pop a colored lens in front of the beam? That's no fun.

Re:Invisible to lasers, anyway.

[ShooterNeo]

Sarcasm, I hope. A colored lens blocks all frequencies except for the ones it allows through (hence the 'color'. A red one lets through red, ect)

A laser beam obviously is only one frequency, so a colored lens does nothing for you. No light at all would get through.

Happy Harry

[jcarkeys]

Harry Potter sits in the corner of the lab in his cloak snickering while the research scientists are excited to get one wavelength invisible.

Re:Happy Harry

[Anonymous Coward]

You do know Harry Potter is a fictional character, right?

Re:Happy Harry

[daveb]

You do know Harry Potter is a fictional character, right?

Yes muggle. No need to fret, "Harry is fictional".

There's no such thing as wizards we^h^h They don't exist.

Re:Happy Harry

[slashbob22]

You do know Harry Potter is a fictional character, right? Which is why he is invisible in the non-fictional wavelength.

Re:Happy Harry

[Eli Gottlieb]

Wizards don't know enough about technology to use Slashdot! You must be a Squib.

How much does it cost?

[Opportunist]

That's what's gonna dictate whether it will be seen on the battlefield or not. If it's cheaper to produce another gunship or tank than to stealth an existing one, it will probably only be used on first strike weapons.

Re:How much does it cost?

[ozydingo]

In its current incarnation it won't be seen on the battlefield at all. Invisible to targeting lasers? Use a different laser wavelength. Invisible to night vision? (Does night vision really only work on a single frequency anyway?) Change the frequency you're looking at. It's not a reliable solution for anything battlefield-worthy until it can encompass a range of frequencies--but it's a good academic first step!

Re:How much does it cost?

[Anonymous Coward]

Err... invisibility cloak? It won't be seen on the battefield either way. Duh.

Re:How much does it cost?

[Opportunist]

A first step is just that, but you're right. Unless there is some progress in the foreseeable future that this can be used on the battlefield, there won't be funding for it. The question is, though, whether detection technology won't progress faster. It would certainly be unrealistic to say that this could cloak against 100% of current detection technology in about 30 years and expect it to be effective. In 30 years, we'll have far more sophisticated detectors which might well render this useless.

Re:How much does it cost?

[Kijori]

That's what's gonna dictate whether it will be seen on the battlefield or not. If it's cheaper to produce another gunship or tank than to stealth an existing one, it will probably only be used on first strike weapons.

Fortunately, this isn't meant to be seen on the battlefield at all.

Re:How much does it cost?

[Opportunist]

Nuclear power wasn't either.

*yawn*

[vxd]

Let me know when it's available for visible light so I can go watch Pamela Anderson have sex live.

Re:*yawn*

[ConvertEJ__]

Yes, just what our society needs. So we get these "invisibility cloaks" and what is next? Use in law enforcement? Cops can spy on us from behind these cloaks? An amendment to the Patriot Act? I'm not saying these are necessarily bad things, but we sure as hell have to weigh the possible negative uses of such a technology.

Following suit with that article about the RIAA pushing for pretexting in California, I could just see them getting their hands on invisibility cloaks.
Be careful pirating music, the RIAA could be in the corner watching!

Re:*yawn*

[BakaHoushi]

Don't worry. We have the technology to prevent such abuse. Simply place an upside down basket on a stick, and place a dollar bill under it. If a record executive or a lawyer is hidden in a corner, they won't be able to resist and the basket will fall on them.

Re:*yawn*

[HateBreeder]

Actually,

If someone could spy on you from within the cloak, it would no longer be invisible, since he would have to absorb photons coming from the object he's observing, instead of passing them through.

this in turn would make him look like a "dark" spot instead of invisible.

Re:*yawn*

[cnettel]

True, but practically we can think about something that lets 0.001 % or so of the light through. In daylight, that should be enough for the observer inside to still see what's going on (the range of usable eyesight is quite astounding), while it might be limited enough to still be hard to detect for those on the outside. (Hint, though: don't use a flashlight while you're wearing the cloak in a very dark room.)

Re:*yawn*

[rhyder128k]

Could save a lot of money if made into a practical device, as we wouldn't have to pay law enforcement. At the end of the shift, let them take the cloak home for personal use.

Re:*yawn*

[Anonymous Coward]

You're an asshole

One step towards the most duped story

[noidentity]

Sure, each article is a slightly different take, but I swear there have been at least four previous articles about some kind of invisibility device in the past year, all turning out to really be invisibility in a very restricted sense, i.e. a particular electronic device doesn't "see" the object.

Re:One step towards the most duped story

[MarkRose]

Are you telling me you have the foresight to see more of these coming? Isn't that blindingly obvious? I wish I had that kind of vision. I have yet to see an invisibility device myself, FWIW.

Re:One step towards the most duped story

[edwardpickman]

Don't worry I take there's an upcoming post on a research group's article that claims invisibility when the viewer closes their eyes. While also not true invisibility the technique does work with all light spectrums. The researchers aren't suggesting a method to get the enemy to close their eyes but they do point out that everything has a downside.

Re:One step towards the most duped story

[Grave]

Oh, it's easy to get the enemy to close their eyes. Just get set their Slashdot comment filter to only show trolls.

Re:One step towards the most duped story

[zCyl]

Don't worry I take there's an upcoming post on a research group's article that claims invisibility when the viewer closes their eyes.

This has been done.

Re:One step towards the most duped story

[e4g4]

It certainly is - strangley enough, I just finished reading an article in this month's scientific american that describes the research mentioned in TFA done by John Pendry regarding an area of study called "plasmonics". Odd that TFA didn't mention the field, as it has applications that are far more realistic in the shorter term than cloaking devices, such as circuits that can convert electromagnetic energy at a given frequency and wavelength to an electron density wave that is the same frequency of the light (thus information can be transmitted from the light and through the material with no loss) but at a much smaller wavelength, meaning the material can transmit the same volume of information through a conduit that it is much smaller than half the wavelength of the light wave, which is currently the limiting factor in optical transmission of data (i.e. fiber).

At any rate, the SciAm article is much more interesting than TFA, and has a lot more information, I highly recommend it.

Meh

[vertigoCiel]

Wake me up when you've got an "invisibility" device that'll let me sneak into the girls locker room without getting seen.

Re:Meh

[NeilTheStupidHead]

Your so-called 'invisibility device' is commonly known as a $50 at a strip club.

Re:Meh

[digitig]

Your so-called 'invisibility device' is commonly known as a $50 at a strip club. I tried that. It didn't work. My wife still saw me :-(

Re:Meh

[NeilTheStupidHead]

If your wife works at a strip club in the first place, I don't see why she had an issue with it. :P

Re:Meh

[Anonymous Coward]

I think I have one, I've been invisible to girls for years.

Re:Meh

[Dr Damage I]

Try sneaking into their locker room and you'll soon learn different ;)

Fitness

[normuser]

As long as there is some sort of fitness standard before you can wear said garments.

Re:Attn. Slashdot:

[Anonymous Coward]

I have nothing against ACs, but I'm sick of this shite. I've set my troll modifier to -6 why isn't it working?

Laser sharks

[unchiujar]

Oh noes, invisible sharks with lasers !!!

Re:Laser sharks

[Anonymous Coward]

-I am sorry sir, we couldnt get sharks.
-What do we have?
-Sea Bass
-Right, Are they invisible?
-Only to one wavelenght
-Oh well, that's a start.

Serious Note: Foreign Students & Critical Tec

[reporter]

The main article mentions that this cloaking technology has military applications. Given the sensitive nature of this technology, should we prohibit certain foreign students from working on research projects exploring cloaking technology?

In the late eighties, the University of Michigan at Ann Arbor prohibited certain foreign students from participating in government-funded research related to VLSI circuits. At the time, various alarmists in Washington warned that Japan would soon eclipse the USA in high technology, and some politicians wanted to prevent certain foreign nationals at our universities from accessing VLSI technology.

I imagine that cloaking technology would be very interesting to students from Iran (seeking a nuclear bomb), India (aggressively developing advanced nuclear weapons), and China (aggressively building a blue-water navy). Washington has already agreed to give civilian nuclear technology to India even though the Indians (1) have refused to sign the nuclear non-proliferation treaty (NPT) and (2) have aggressively develop nuclear weapons. Should Washington further enhance Indian military ambitions by allowing Indian students to work on cloaking technology at America universities?

Sadder, but wiser.

[Anonymous Coward]

A friendly note to the photonics project managers, researchers and general staff:

Don't make the same mistake I did. Learn from my experience that one should never, ever put the invisibility generator on top of the anti-gravity device.

Oh no!

[Mikachu]

It's Denton. Remember the briefing.

Don't mod me down just because you don't get it. ;)

Re:Oh no!

[freyyr890]

Deus Ex, right?

That was looking to be a good game, until I lost the disc in the third mission...

Re:Oh no!

[Mikachu]

Right.

Third mission? Aww, that sucks. Amazing game.

Re:Oh no!

[freyyr890]

Suppose I could still no-cd it, since it's still on my hard drive and it is a full install...

*Rushes to cracks site.*

night-vision goggles or laser target designators..

[Bananatree3]

Orrrr...Hiding in Dark Rooms!!

Re:Attn. Slashdot:

[Anonymous Coward]

I've set mine to +5.... I know its kinda messed up. but some times people wrongly get modded troll.

But this type of stuff has to go. what type of low life has nothing better to do then refresh the front page for slashdot every minute to see if they can get the first post about some fucked up stuff.

There needs to be a report abuse button to have people like the sick fuck in the above post banned from slashdot.

Invisibility cloak?

[Anonymous Coward]

Hey, cool! A cloak of invisibility +5 funny!

So, where is it?

[FMota91]

Nothing to see here, move along.

Playing

[Anonymous Coward]

Playing Harry Potter just became more fun than ever!

Re:Playing

[Anonymous Coward]

"Draco, Draco, wherefore art thou Draco?"

is it telling the future that....

[holywarrior21c]

the coming of purdue nukem?

Obligatory Star Trek Quote

[lord_mike]

Spock: Invisibility is theoretically possible, Captain--selectively bending light. But the power cost is enormous. They may have solved that.

Roddenberry effect

[Anonymous Coward]

If it renders lasers less effective as weapons, then the natural result is development of multi-spectrum Phasers. You heard it hear folks! The cloaking device came first!

Frickin Romulans.

Re:Serious Note: Foreign Students & Critical T

[Anonymous Coward]

GOD BLESS AMERICA! fixed

Re:Attn. Slashdot:

[Anonymous Coward]

Ok that was funny, but I didn't click on it. I still want your crap off this page. You're somewhat talented and could be funny (2nd post was funny, content still offensive), but ultimately when I'm at work and I click on this shit I'd really just like to see you swallowing a handful of razorblades.

Problem with Invisibility Cloaks in General ...

[i_wanna_be_a_scienti]

What about the ground? Can the light even bend around an object that is stuck to another? I don't think so ...
So wouldn't it make two dark spots on the ground? that could be used to identify if someone is using an invisibility cloak.

Re:Problem with Invisibility Cloaks in General ...

[Skrynkelberg]

The light doesn't literally bend "around" the object (as in, in the air surrounding the object), but enters the top layer of the object, bounces around, and exits on the other side. Therefore, standing on the ground won't be a problem.

Re:Problem with Invisibility Cloaks in General ...

[i_wanna_be_a_scienti]

why wouldn't it still be a problem?
the reason that people think that they don't see anyone there is because there is light bouncing off other surfaces, then going through that 'cloak' like you said, then reaching their eyes.
however, the light can't bounce around the barrier that your feet make with the ground, so can the light bounce around to the ground, for it to then be reflected off of the ground to the observer's eyes so that they can see the ground?

Re:Problem with Invisibility Cloaks in General ...

[KitsuneSoftware]

the light can't bounce around the barrier that your feet make with the ground

Sure it can. You just make your shoes out of the same thing as the rest of the "cloak". Light goes in, bounces around in the material of the cloak itself, hits the ground, bounces straight back into the "cloak" material, bounces around some more, and leaves again.

Precious, my precious

[OldManAndTheC]

According to TFA:

Leonhardt, a professor of theoretical physics, wrote a commentary piece about the Purdue paper appearing in the same issue of Nature Photonics. In the commentary, he compares the Purdue design to the Roman creation of "the first optical metamaterial," a type of glass containing nanometer-scale particles of gold. In ordinary daylight, a cup made of the glass appeared green, but then it glowed ruby when illuminated from the inside.

So basically, this will be made out of (a form of) gold, and encircle the object to be rendered invisible?

I'm betting that, in order to work, it will need to be inscribed with the phrase: Ash nazg durbatulûk, ash nazg gimbatul, ash nazg thrakatulûk, agh burzum-ishi krimpatul.

Re:Precious, my precious

[swillden]

Ash nazg durbatulûk, ash nazg gimbatul, ash nazg thrakatulûk, agh burzum-ishi krimpatul.

Please tell me you looked that up.

Re:Precious, my precious

[Anonymous Coward]

I think we both know, deep down, that he didn't.

Re:Precious, my precious

[OldManAndTheC]

Please tell me you looked that up.

I did ... but only to check the spelling :)

Re:Precious, my precious

[andphi]

You're new here, aren't you?

Re:Attn. Slashdot:

[Anonymous Coward]

that's why I responded. /. is a great site for professionals (with or without our flaws), great interviews, direct link to Intel and of course goatse I really don't understand. report abuse would be great so this shite could be deleted.

night vision goggles and lasers, no.

[plasmacutter]

first off, theyre slowly replacing aging nvg's with FLIR systems, second nvg's sensed a spectrum, though i forgot which one, ultraviolet was it?, the point is its not a single wavelength... even if i'm wrong and it is only one wavelength then it would be trivial to broaden the spectrum or have the sensors modulate.

the same thing with a laser, you modulate the beam according to a hash function for each laser/missile pair, the string that produces the hash code could easily be communicated real time from air support to the troops on the ground painting the target.

congrats, you added 3 more seconds at most to a target's life. even if that allows say, a tank, to get off one more shot the expense and other undocumented and probably cumbersome changes are not worth it.

now if/when they develop one that cloaks across the entire practical spectrum of light you may have a problem, but not one that cant be solved through the trivial process of painting the ground in front of the target and having the guidance system deliberately raise the elevation of the impact point by.. say.. 10 feet... let alone using IR or radar/gps guidance instead.

Re:night vision goggles and lasers, no.

[hazee]

Not quite sure what you mean about modulating a laser beam. Presumably you can switch it on and off in whatever fancy scheme you like, but it's going to remain the same wavelength. As others have mentioned, wouldn't you need different lasers to get different wavelengths? I seem to recall that dye lasers shift the output from one frequency to another, but not sure how practical this would be in a battlefield.

Also, as regards communications between planes and ground troops - presumably planes want to minimise their transmissions, to prevent becoming targets themselves, especially if they're trying to be stealthy. How long does a bomb take to fall from 20,000 feet? I wouldn't want to broadcast my location for that long. Ditto for the ground troops.

Finally, mightn't 3 seconds be long enough to save the target's life? If they just switched it on at the last second, and then dodged?

Re:night vision goggles and lasers, no.

[Dr Damage I]

congrats, you added 3 more seconds at most to a target's life

On a battlefield, 3 seconds can be an eternity, particularly if that extra shot lets it kill the target that would otherwise have killed it.

A little note about free speech

[Anonymous Coward]

I am not the troll who posted the garbage, but who cares? it is a troll. A troll is supposed to invoke a response. If you are that weak minded to be taken by a troll, than the troll has won.

Now about free speech. It is already eroding away in America. If you have enough money, you can block any kind of message you want through the courts. Judges are smoothed talked by lawyers into believing our right to free speech does not exist. Now what makes slashdot great is free speech. lets hope slashdot never blocks anything unless it is, well, subpoenad by the court.. *sigh* (which it has been before i believe)

Re:A little note about free speech

[lordmatthias215]

While I agree that Slashdot shouldn't ban any exercise of free speech, I'm pretty sure one of this site's rules is no advertising your site in discussions, espeically if it has nothing to do with the discussion at hand. This guy is just spamming articles with ads, without making even the slightest effort to make it look like a normal response. I agree that there needs to be a "report abuse" link that /. higher-ups can then review and make a decision based on. There's a difference between free speech and system abuse.

Re:A little note about free speech

[Anonymous Coward]

Where do you draw the line between free speech and system abuse?

If there is free speech, it means you tolerate everything including (but not limited to) unpopular opinions, insults about you or your loved ones, ads and whatever.

The moment you start deleting some form of speech because it did not conform to some rule (in this case, the rule being 'no ads'), then you are controlling speech.

You recommend that /. higher ups should be able to remove posts based on some decision. Who's to say that such power won't be abused?

Almost everything in life is in a shade of gray. But in my opinion, free speech is a black & white issue. If you control speech based on ANY rule, then it is no longer free. Just my 0.02 bytes.

Re:A little note about free speech

[Anonymous Coward]

I am not the troll who posted the garbage, but who cares? it is a troll. A troll is supposed to invoke a response. If you are that weak minded to be taken by a troll, than the troll has won.

Now about free speech. It is already eroding away in America. If you have enough money, you can block any kind of message you want through the courts. Judges are smoothed talked by lawyers into believing our right to free speech does not exist. Now what makes slashdot great is free speech. lets hope slashdot never blocks anything unless it is, well, subpoenad by the court.. *sigh* (which it has been before i believe)

I wanna take a nice long dump on that face of yours.

wonder if Masamune Shirow knows about this?

[Petkov]

Ghost in the shell anyone?

Completed already?

[Non-CleverNickName]

Hey, for all we know, someone could have already completed the perfect cloaking device...they just can't find the off switch.

Re:Serious Note: Foreign Students & Critical T

[cyphercell]

If we don't let Japan and China learn about the technology, who will build it? All joking aside, countermeasures already exist and in many cases are far more advanced. Either way India is not considered an enemy http://www.washingtonpost.com/wp-dyn/content/artic le/2006/04/19/AR2006041902480.html. If you're concerned about outsourcing, don't be, let the Indians go to school in the US, that way at least our universities don't rot from lack of use.

Lightbending 101

[__aawkdb2598]

This innovation and others like it have seen far too much press already. I know, I know, it's slashdot and no one RTFA anyway, but if you did you'd quickly realize that there really is nothing to see here. Let me explain at least for those of you who will read a comment if not any of the articles appearing in popular science sources for the last several months:

Imagine for the moment placing an object behind a mirror. Better yet, inside a mirror. Amazing! You cloaked it from observation from visible wavelengths! Understood, this is much more meta and complex than all that. It bends the light around instead of sending it away. But that's all. In the same way that you can't see anything on the other side of the mirror, nothing on the other side of the mirror can see you. We're not going to see invisibility cloaks or special forces in lightbending armor out of this, because even if the technology were practical and cheap the special forces would still be blind. Any light you let in is light that's not making you invisible by being elsewhere.
These results are undeniably groundbreaking, but they are received as something entirely different from what they really are.

Re:Lightbending 101

[freedumb2000]

Ok, how do mirrored sunglases work then?

Re:Lightbending 101

[Venerable Vegetable]

Uuh, what about covering everything except the eyes?

Or use it on robots which don't need to see?

Re:Lightbending 101

[Anonymous Coward]

In several of the Star Wars novels, some of the Imperial generals (I believe Thrawn among them, though I could be misremembering) used cloaked star destroyers which were, as you say they would be, blind from the inside as well as the outside. Despite this limitation, the tactical uses were still significant.

Re:Lightbending 101

[ultramutalisk]

Well, if you only bend light of the visible spectrum around someone, they could wear infrared or ultraviolet goggles to be able to see outside of this field.

Re:Lightbending 101

[VanessaE]

Depending on how you'd actually implement the rest of the cloak, the "wearer" wouldn't necessarily have to be blind. Take your cloaked object, let's assume the cloaking material is a solid or at least is applied to a solid surface, and punch two very tiny holes in exactly opposite sides of the object. The holes only need to be a couple milimeters in diameter - just large enough to point a camera at to see through. Now place a mirroring system like those used by teleprompters (where they float the text in front of the camera for the subject to read, but the camera only sees the subject and not the text) in front of each camera, and a projector aimed at each mirror. Each projector outputs whatever is captured by the camera on the opposite side of the cloaked object, while at the same time monitors inside the object display the cameras' images.

Given the nature of the military and the technology we have today, the whole camera+projector+mirror array could probably be made into a single compact unit no larger than a bottle of nail polish.

Of course this would only be of limited help, but it's a start. You could also design the material around the holes to compensate both in light collected and light projected (even if you have to scatter the light - think of how the glow from a street lamp partially obscures the lamp housing itself), and use that in conjunction with the camera/teleprompter idea. Either way, the observer wouldn't see anything significant relative to the rest of the cloaked region (I'm assuming the result would look something like the cloak in Predator, rather than near-perfect like in Star Trek.)

obligatory ghost in the shell.

[plasmacutter]

what say you to the thermoptic camo from ghost in the shell, which is an actual clothing item composed of millions of pico to nano scale fiber optic cameras and projectors which fluidly blend you into the surroundings. a semitransparent veil covers the face, completing the full body cloak, but facilitating vision in the same way those pointilism ads across city buses present a picture to onlookers while allowing passengers a view outside.

how much more complex would it be to create light bending hardware with these kind of microperforations.

Re:obligatory ghost in the shell.

[__aawkdb2598]

Right, I've always thought that if we're likely to see anything approaching a "cloak of invisibility" that a chameleon approach is a lot more feasible. Of course one could use a partially transparent/lightbending region or pinhole cameras to let someone inside such a metamaterial shell to see outside, but my point was more that there have been so many articles of this sort recently. The summaries and titles are almost always misleading and then people go on to hypothesize about future developments in the field without having ever done more than read the title of the summary.

The chameleon or mimicry approach does seem a lot more practical a direction to work in, especially for vehicle-mounted systems. Of course, there are other problems with that approach. Generating that much light, unless done more efficiently than we are capable of doing now, will also generate heat and possibly noise in other portions of the spectrum. Even assuming a much tighter system, which is fair enough because we're already assuming great advances in optics and computing with such a suit, where do you get the power?

Then there are lighting problems. You have to account for not only normal lighting and brighter but also the possibility that some genius will come up with the idea of defeating your stealth suit with a bit of high-intensity coherent light. Unless the suit can also detect and respond to a sudden and very localized increase in intensity and generate a matching pattern and intensity at the appropriate exit point, you might have the situation where a super-operative with a stealth suit could be humbled by a laser-pointer. Much like stealth bombers and cell phones. It wouldn't even necessarily be that hard to add a bit of optics to a laser sight on an assault rifle, say a small mirror capable of allowing your laser to cover a spotlight-sized area by continuously varying the angle of emergence by some small amount. Couple this with a bit of cheap range-finding and it should be possible to notice the extra latency as the laser is emulated by the suit systems even if it were capable of doing so.

So, win some, lose some. It'd make more sense to try for highly-advanced camouflage than invisibility. Say something that will change pigments to match the environment closely and calculatedly. This seems to me even more feasible. Projectors could allow you to be even more precise, but they have other hurdles to overcome. Thanks for the thoughtful reply!

Re:Serious Note: Foreign Students & Critical T

[Anonymous Coward]

Who the fuck do you think IS the research department? My school is 53% asian, and 26% caucasian (which includes middle easterners, if you didn't know). And that's *including* the whitey stuff like social sciences and humanities. There are maybe five white guys in a lecture hall of 200 engineers. My most recent physics lab group consisted of two chinese, one japanese, one iranian, and myself (central/east european mutt). One of the chinese guys and the iranian were attempting to get citizenship. This is not uncommon, based on previous groups and discussion sections I've been involved in. The graduate level is even more foreign.

I've had two white professors the entire time I've been there (4 years @ ~16 classes a year). Indians, Turks, Iranians, Iraqis, Georgians, Japanese, Chinese, etc...all with tenure (or with tenure on its way). Ban the foreign nationals and the engineering and science universities would have to shut down, leading to an even wider gap between the U.S. and its tech competitors.

Link to Paper

[nleaf]

The paper can be downloaded for free on arxiv.org: Optical Cloaking with Non-Magnetic Metamaterials

I see a lot of comments along the lines of "One wavelength cloaking will never be useful because of ____ and ____." Firstly, the vast majority of research is done incrementally, and this is a good first step. Secondly, funding is a necessary evil, and towards that end nothing beats a working demonstration that smells like fresh progress.

Re:Link to Paper

[bensch128]

and towards that end nothing beats a working demonstration that smells like fresh progress.

Funny, but I think that a working demonstration will not be displayed for the next 50 years as this thing will probably be wrapped up tight with topsecret classifications from now on. I can't imagine how happy the USAF is too see this thing. (As well as fans of Ghost in the Machine, heh)

Ben

Russian Dolls

[Nazlfrag]

To combat against multiple frequencies, you could place the cloak for X inside the cloak for Y inside the cloak for Z. Extending this way to full spectrum would be impractical, but multiple frequencies could more easily be blocked.

Re:Russian Dolls

[Venerable Vegetable]

That would only work if the cloak was completely transparant to all frequencies except the one it's bending. I seriously doubt that. More likely, the outside cloak will bend one frequency around it and reflect the others like normal materials.

Re:Russian Dolls

[Skrynkelberg]

No, because the Z- (and Y-) cloak is visible to the X wavelength, this won't work.

Re:Serious Note: Foreign Students & Critical T

[Anonymous Coward]

I agree: Truly it is only safe for America to weild supreme power in this world because they are the only ones who are responsible enough to do so. End sarcasm. Maybe the US should have to sign the nuclear non-proliferation treaty too?

You won't see anything but yourself

[Richard Kirk]

Light can usually go along a path in either direction. If light isn't getting from you to the outside world. If the 'invisibility cloak' is a type of Luneborg lens with phonotonics materials to get the high refractive incides needed to get light to avoid the bit in the middle - the sort of thing in this month's 'Scientific American' - then yo will seem to be at the centre of a shiny ball. Kinda interesting to know how you would decide when all the bad guys had gone away, and it was save to take a peek out.

Stick to the half-silvered mirror, ya perv.

What is it like to wear ?

[Alain Williams]

I assume that if you wear one of these then you see nothing from 'outside' at that particular shade of red.

So if they succeed in making one that works at all wavelengths of visible light - one could not see out. However: imperfections would let some light leak in, but the direction that it came from might be distorted and so give a very blurred view of the rest of the world.

Re:What is it like to wear ?

[Godman]

Which is why you don't cover your fricking eyes.

And if you need to be absolutely hidden, you *gasp* put your hands over them, or wear a baseball type cap that will enable you to see well enough to walk, but not be seen.

Re:What is it like to wear ?

[neminem]

Of course, you could then hide a camera somewhere, and put the receiver for the camera inside the person's cloak. You might not be able to see with your unaided vision, but that doesn't stop you from being able to see with aided vision - and a small camera is much easier to hide than a person.

Re:Attn. Slashdot:

[WrongSizeGlass]

I've set my troll modifier to -6 why isn't it working? Perhaps your invisibility cloak is draining your power?


warning:The above content tests positive for sarcasm and/or is a failed attempt at humor and should be taken with a pound of salt.

Re:Serious Note: Foreign Students & Critical T

[rucs_hack]

who needs to develop more countermeasures? Mobile phone transmitters could be used, just search for the blank area...

Invisible on a SINGLE wavelength...

[Anonymous Coward]

Our red-light invisible, green cloaked overlords...

Also, even if it could cover the full visible spectrum, there's still that problem of IR emission. Only obvious way to fix that would make the garment uncomfortably hot to the wearer.

How to Welcome

[SorryTomato]

Dear AskSlashdot,
How does one welcome invisible overlords?

nonplussed,
SorryTomato.

Dirt/damage resilience?

[Jesus_666]

I'm not really into nanostructures, but this sounds pretty fragile. Someone has already pointed out that mere dirt could render it useless - but what about damage? Military vehicles aren't exactly going to be dusted off with badger hair brushes, so if the nanostructure is eroded by water (and cleaning brushes) the coat isn't going to last long. And if water can't do it small stones probably can and there are lots of those in the field.

I see this as a general problem with light-bending nanomaterials - while they might work in a lab environment, real-world environments have enough ways of disrupting them to make them much less useful.

Re:Serious Note: Foreign Students & Critical T

[kalidasa]

There's nothing in this article to suggest that the student with the Indian name (Uday K. Chettiar) is not an American citizen, nor that Wenshan Cai or Alexander V. Kildishev are not American citizens, or that Vladimir Shalaev himself is not a US citizen (the fact that he was educated in Russia isn't an impediment: my grandparents were educated in England, and became citizens as adults); a cursory Google search finds nothing to suggest that they are not US citizens, either. However, I do know that Title 22 of the US code includes International Traffic in Arms Regulations (http://www.epic.org/crypto/export_controls/itar.h tml), and that universities and private companies in the US are required to stick to these regulations pretty closely, for fear of losing all federal funding: technologies that are covered under these regulations can only be worked on by US Citizens and those with "permanent resident" (green card) status. The fact that there have been a number of prosecutions of companies for technology transfers to China is proof that these regulations are taken seriously (though one does wonder about equality of enforcement with this particular administration).

So, apparently you assume that anyone without a European name is not a citizen - or, at least, anyone with an Indian name is not a citizen: you didn't question Prof. Shalaev, Mr. Cai, or Mr. Kildishev. Looking at your website (http://www.geocities.com/deskofreporter/), I see that you do raise some interesting points about Taiwan's relationship with China, but that the tone you use in doing so has an aroma of xenophobia. I'd suggest that you look into the history of great American immigrant patriots, beginning with Alexander Hamilton and continuing on through Albert Einstein (he became an American citizen in 1940 and remained one until his death).

So if I..

[Ricken]

Calculations indicate the device would make an object invisible in a wavelength of 632.8 nanometers, which corresponds to the color red.

So if I wear one of those together with my wife's red dress I should be ok, right? Game on!

Re:Serious Note: Foreign Students & Critical T

[h4rm0ny]

Out of curiousity, what comment would you make about Japan or China excluding US scientists access to this research? Would you object? Because the way things are going, the US is going to be increasingly finding itself in the position of other countries having a lead in certain technological areas.

As to India not signing up to the NPT, that would carry a little more moral weight if the US wasn't ignoring the treaty itself.

And Iranian students seeking bombs, is that a particular problem at your university?

Re:Serious Note: Foreign Students & Critical T

[kmac06]

I'd suggest that you look at the make up of any engineering or physics grad school in this country. At most, it's 50% American students. The assumption that these students with foreign-sounding names are foreign is a very safe one. Now I do think the GP is being alarmist, and that the potential military uses of this technology is so far off that restricting work on this based on citizenship is absurd.

old

[Sobieski]

this was in the last issue of the swedish magazine "Illustrerad Vetenskap", which i got last week (and they had nicer graphics ^^)

Re:old

[Skrynkelberg]

Actually, the article in the magazine was about bending light in the microwave spectrum (which another \.-article covered quite a while ago). Not until now have they managed to do the same in the visible spectrum. I have yet to come across a printed magazine with fresher news than slashdot.

I Already Wear an Invisible Cloak!

[Cruxus]

And you thought I wasn't wearing anything at all!

Re:Attn. Slashdot:

[dheera]

i think a good system would be to say if a post gets modded troll at least 6 times, it should get deleted completely. i would hate to see Slashdot banned in schools, to see Slashdot be a workplace risk, and something that can't be shared with youngsters.

Re:Serious Note: Foreign Students & Critical T

[Anonymous Coward]

Are you kidding me, foreign students already have the shaft in terms of univerity-level research. I know of a some research or fellowships run by an NSF grant excludes foreign students from working. I have a friend who has been looking for a lab to get some experience in and quite a few times they were like "sorry we can't take foreign students."

Re:Serious Note: Foreign Students & Critical T

[Zgonjko]

Many, if not most of the leading researchers in the past century in the US have been foreigners, many of whom started out as students. The government has allowed even former nazis to be at the head of some of the most amazing development, like Von Braun, the man responsible for getting us to the moon. It's not even a question of whether we should let foreign students have access to this technology, because without them the technological development would be halved.

Invisibility cloaks are today's perpetual motion

[dpbsmith]

Goodness, I think I've read how many articles about this in the past couple of years? Six? Ten? They all have little glitches, like only working from one point of view, or only at one wavelength (frequently not a visible wavelength), or being pure simulations that have not even been tried in the laboratory yet. Many of them don't sound like "cloaks" at all, but like huge physical plants of machinery surrounding the object to be "cloaked."

But they're all "promising" and they all "take a step toward" something that "could" be an invisibility cloak.

I don't say it's necessarily all bogus, but I have to wonder seriously what the huge drumbeat of publicity is all about. Reminds me of cold fusion a few years ago.

Hey, '''I''' have a promising approach that is a step toward something that could be perpetual motion, and I have diagrams and computer animations to prove it. Anyone want to fund my research?

Re:Invisibility cloaks are today's perpetual motio

[Maian]

You're neglecting one key fact: perpetual motion is impossible because it violates the laws of thermodynamics. What laws does cloaking violate?

Oblig. nethack

[frostband]

Yes, but does it have a +6 enchantment?

Re:Invisibility cloaks are today's perpetual motio

[Skrynkelberg]

Actually, cold fusion was never about perpetual motion. If it was, serious scientists would never even have shot a glance at it. The point the grandparent is trying to make is that it is a giant leap from cloaking one wavelength to cloaking all. The existing approach just doesn't cut it; they'll need a whole new idea to make it even theoretically possible.

STEATH CAMOUFLAGE?

[machrider]

Snake! WHAT HAPPENED? Snake! SNAAAAAAAAAAKE!

Re:Serious Note: Foreign Students & Critical T

[Anonymous Coward]

Your point is well taken, but students usually are contributing to scientific research not just learning from it. Also knowledge is usually classified only as to how it is applied to military technology, not just because it could be applied to military technology.

How appropriate, Purdue's full of ugly chicks

[Anonymous Coward]

Great idea, get those chinese grad students to build a cloaking device for ugly coeds.

Slight problem

[Anonymous Coward]

Okay, slight problem... The band of infrared radiation is not a single wavelength. Making yourself invisible to ONE wavelength within the IR band will not make you invisible to night-vision goggles. With night-vision goggles, you would not be limited to a single frequency of light.

Re:Serious Note: Foreign Students & Critical T

[Anonymous Coward]

if they want to cut the US out of technology, we show them who is boss. it's that simple.

Re:Mod Parent Down!

[kalidasa]

Of course, if you weren't an anonymous coward, I'd have you for slander.

Re:Serious Note: Foreign Students & Critical T

[kalidasa]

The US blows hot and cold on practically all treaties, depending on who is in the White House. That doesn't excuse India from it's behavior regarding proliferation. The problem here isn't whether foreign scientists should be excluded from certain kinds of work - they *should*, and they *are*, under the terms of ITAR, unless they have made the commitment of obtaining permanent residence status. The problem is the assumption that all of these folks are "foreigners." Just because someone has non-Anglo-Saxon name, or even an accent, does not mean that person is not an American citizen: and there is nothing in this article or in the websites I could find mentioning the students that suggests that they are not American citizens, and if the technology is sensitive military use technology, they wouldn't be allowed to work on it unless they were at least permanent residents (a status which it is rather difficult for a student to obtain).

By the way, some idiot decided to slander me in a response to my other posting in this thread by claiming that I'm a racist (I will charitably assume that it was not "reporter"). I'm not quite sure how explaining that a bunch of kids with Indian, Chinese, and Russian names could very well be Americans makes a white Anglo-Saxon American a racist, but I suppose I'd be an idiot to expect any kind of consistency on the part of such a poster.

Japanese Transparency

[Mocow]

Didn't Japan made something similar to this already? I am not sure if it uses the same concept and I am not familiar with optical technology but here's a link to the video on youtube. http://youtube.com/watch?v=BeeigdXQ7-E

Re:Invisibility cloaks are today's perpetual motio

[Anonymous Coward]

It's true that sometimes a single idea even while still unproven brings about some excessive publicity. But clearly having the capacity to mirror certain wavelenths of light at this point tells us that alot more is possible. "cloaking" technology if it begins to prove even further that it can be done will find plenty of venues in which it could be funded.