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Science Technology

Glass Invisibility Cloak Shields Infrared 115

Posted by kdawson from the moving-on-up dept.
An anonymous reader writes with the latest advance in the quest for a cloak of invisibility (Michigan Tech University's press release). We've been following this research as it develops; here are stories from each of the last four years. "Invisibility cloaks are slowly working their way up to shorter wavelengths — starting at millimeter-long microwaves and working their way to the nanometer wavelengths of visible light. EETimes says we are about half way there — micrometer wavelengths — in this story about using chalcogenide glass to create invisibility cloaks in the infrared. Quoting: 'Invisibility cloaks cast in chalcogenide glass can render objects invisible to infrared frequencies of light, according to researchers at Michigan Technological University... Most other demonstrations of invisibility cloaks have used metamaterials composed of free-space split-ring resonators that were constructed from metal printed-circuit board traces surrounded by traditional dielectric material. The Michigan Tech researchers... claim that by substituting nonmetallic glass resonators made from chalcogenide glass, infrared cloaks are possible too...'"
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Glass Invisibility Cloak Shields Infrared More

Glass Invisibility Cloak Shields Infrared

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  • Goodness me! (Score:5, Funny)

    by Fluffeh ( 1273756 ) on Sunday July 25, 2010 @06:53PM (#33024396)
    I so totally didn't see this story coming this morning...

    • Re:Goodness me! (Score:5, Funny)

      by Anonymous Coward on Sunday July 25, 2010 @08:04PM (#33024776)
      this friends is why Funny mods don't contribute to a user's positive karma. almost none of them display any real wit and are generally not very funny. this post here is in the same ballpark as the puns that news anchors constantly use i.e. "today we have *shocking* news about your electricity prices". i guess the viewer is supposed to say "ha-ha, it's about electricity and he said shocking, how amazingly clever and original and humorous!" those viewers are the same people who mod up posts like the parent post. "ha-ha, it's about a cloak and cloaks make things invisible so he didn't see this story coming, how amazingly clever and original and humorous!" except that it wasn't.

      on the plus side, at least it wasn't a ten thousandth iteration of a tired old Slashdot meme. though lame jokes like this getting modded to +5 Funny is a Slashdot meme in and of itself.

      • on the plus side, at least it wasn't a ten thousandth iteration of a tired old Slashdot meme. though lame jokes like this getting modded to +5 Funny is a Slashdot meme in and of itself.

        Sorry, just used my mod points or I would mod you up.

      • how amazingly clever and original and humorous!" except that it wasn't (snip) ...on the plus side, at least it wasn't a ten thousandth iteration of a tired old Slashdot meme.

        but I laughed at that post, you insensitive clod!

      • Re: (Score:1, Offtopic)

        by PitaBred ( 632671 )

        I think you're just jealous that you didn't think of it first

      • If you don't like posts modded funny, you can have them not show up. For the rest of us who like a good laugh, we will continue to have them given extra preference.
      • Getting the post before the second one gets the most eyeballs, including the pseudomods, and statistically speaking, will have the best chance of getting a +5 moderation, regardless of the content of the post.

        I know... i've done it a few times myself.
      • Mod parent -1 humourless bastard

      • I find it funny that they modded you funny for slamming the mods for modding parent funny.

        I feel like I'm stuck in an iterative funny loop...

      • The Anonymous Coward's post was so bad it was deemed a capital offense, ha-ha!

      • So, what you're saying is that you don't appreciate his transparent comedy?

      • +5, Hot grits in Soviet Russia spill Natalie Portman

    • Re:Goodness me! (Score:5, Funny)

      by tenex ( 766192 ) on Sunday July 25, 2010 @08:27PM (#33024890)

      An invisibility cloak eh... right then; I'll believe it when I see it.

    • Re: (Score:2)

      by SeaFox ( 739806 )

      ...and it's such hot news!

  • "halfway there" on a logarithmic scale (Score:1, Insightful)

    by Anonymous Coward

    is not halfway there

    • Re: (Score:3, Informative)

      by CheshireCatCO ( 185193 )

      Yes. On a linear scale, we're basically all the way there. So what's you're point?

      Seriously, log scales are the better way to measure this sort of thing, not just for convenience. Look at Moore's law.

      On the other hand, I'm confused as to why we're only halfway there. Light wavelenghts aren't nanometer in size, they're hundreds of nanometers. Which means that we've gone from 1E-3 m to 1E-6 on our way to 1E-7. In log space, we're 75% of the way there.

  • Military (Score:5, Insightful)

    by Pharmboy ( 216950 ) on Sunday July 25, 2010 @06:55PM (#33024418) Journal

    Once you can cloak infrared, then you have a genuine military grade cloak with true stealth capability and applications. Expect most of the real breakthroughs to never see the front page of /. or any other news source. Except maybe Wikileaks.

    • Re:Military (Score:5, Insightful)

      by Anonymous Coward on Sunday July 25, 2010 @07:01PM (#33024454)

      Better yet, you'll be able to hide from mosquitos!

      • Re: (Score:3, Informative)

        by Ihmhi ( 1206036 )

        I thought mosquitoes found animals by the carbon dioxide they breath out...

        • *Sneering* What planet do you come from?

        • A large part of the mosquito’s sense of smell, or olfactory system, is devoted to sniffing out human targets. Of 72 types of odour receptor on its antennae, at least 27 are tuned to detect chemicals found in perspiration.

          So carbon dioxide, octenol and nonanal, among many others.
          Also nonanal acts synergistically with carbon dioxide".

    • Well, yea until the news headlines is "Armed robber evades police chopper by employing military technology that makes him invisible to the high tech night-vision designed to track suspects in the dark." Followed with a headline, "City counsel is to decide whether to spend 10 billion dollars or not to upgrade the aging state of the art police copters purchased not just 5 years ago" followed by the headline "schools suspend bus service in bid to save money afte the last levee failed.".

      Yea, it will be buried u

    • Anyone using infra red detection goggles/devices will see a very unusual cool spot that stands out against the background (try out some first or second gen goggles some time). And it will be especially noticeable if this cool spot is moving. Good milspec devices like this, to be really stealthy, would detect and measure the surrounding background heat levels and *match them*, like a chameleon matches background visual colors.

      • No: not really (Score:3, Interesting)

        by Required Snark ( 1702878 )
        If this can be made to work at the frequencies used by infrared targeting sensors it could be extremely useful. It doesn't have to 'match' anything. All it has to do is make the platform not emit in the expected direction, but in a direction that will make tracking difficult. Remember that these kind of meta-materials have a negative index of reflection, so they can act like unusual lenses. It doesn't even have to do this for the entire vehicle, just the hot parts used for targeting. For example, this could

      • Re: (Score:3, Informative)

        by hakey ( 1227664 )

        measure the surrounding background heat levels and *match them*, like a chameleon matches background visual colors

        How invisibility cloaks work http://www.howstuffworks.com/invisibility-cloak.htm [howstuffworks.com]

      • There is no absorption of infrared. The waves are carried around the surface, reflect off what's behind it, and are then carried back around the surface again. Aberrations may be generated by the process, though it would be very convincing to the untrained mind that there was nothing there.

    • Re:Military (Score:4, Interesting)

      by the_other_chewey ( 1119125 ) on Sunday July 25, 2010 @08:39PM (#33024942)
      Except that this doesn't cloak an objects infrared emissions, it makes it invisible to surrounding IR light.
      There's nothing at all hiding the infrared emissions of the object hidden by the cloak.

      Unless you find a way to break a couple of thermodynamic laws, there's no real way to completely hide an
      object's thermal emissions if it is warmer than its surroundings.

      • No, but if you could refract it, and spread it out over a larger than expected area, it could change the profile to a great enough degree for it to be useful.

      • Re:Military (Score:4, Interesting)

        by Pharmboy ( 216950 ) on Sunday July 25, 2010 @10:18PM (#33025550) Journal

        Unless you find a way to break a couple of thermodynamic laws, there's no real way to completely hide an
        object's thermal emissions if it is warmer than its surroundings.

        Not exactly true. Military jet nozzles are designed to create a smaller IR footprint, and there are several ways to reduce your thermal print. Obviously creating less heat, storing heat to prevent it from being emitted, pushing it in a direction 180 degrees away from the radar source, etc. It starts with having more imagination. The goal is NOT to make IR emissions "disappear", only to create the illusion that they have by controlling where they go. To buy time.

        Sometimes, you can fool a system into thinking you are much smaller than you are, or depending on the threshold of the system, drastically increase the amount of time before you are noticed at all. Even stealth aircraft are not invisible to radar, but by the time the radar sees them, the radar site has been taken down by air to surface munitions. Same idea, only giving you a larger window before you are noticed, thus defeating better radar systems. We can already absorb and deflect microwaves fairly well, adding IR to aircraft defense would be a very big deal, for protection from radars, and from air to air and surface to air munitions. ie: Air superiority.

      • Except that this doesn't cloak an objects infrared emissions, it makes it invisible to surrounding IR light.

        So what if you turned the cloak inside out then?



        just kidding

    • You still need to put your heat somewhere. As a person, you won't radiate a whole lot of heat but anything with an engine will be pumping out hot exhaust.

      Anyway, from the sound it it, they're just saying that they're working their way up the spectrum to visible light. Whether or not it works for every wavelength below infrared is another question. If it can't deal with radar, well... I guess we could have layered defense and offense lines using different cloaks.

    • yeah, i was thinking exactly the same thing. not only does this defeat regular night vision but it would also defeat thermal imaging. and radar invisibility tho not nearly as impressive to normal nonscientific minded folks, is old hat. yes, that means microwave band. sounds to me like sonar vision is gonna have to be looked at, as is far UV. i'm sure the 'invisibility' is not perfect though, most likely along the lines of what was depicted in 'predator' where a small amount of visual distortion is visible a

  • For grow houses to keep the cops from snooping.

    • Re: (Score:2, Insightful)

      by DarkIye ( 875062 )
      Because a visible house with a completely transparent heat signature isn't going to raise any eyebrows.

    • Re: (Score:2)

      by Khyber ( 864651 )

      A totally cold spot makes no sense in almost any house. If that room is showing nil IR emissions, then I'm going to assume tons of non-standard insulation is being used to hide something.

      You're better off just using LED lights and reducing your heat signature. Oh, and don't grow illegally, that helps, too.

      • The transparency will just have to be dynamically adjustable. If you let the right amount through it will be more effective in blending with the surroundings, otherwise it wouldn't be cloaking.

        • Re: (Score:2)

          by Khyber ( 864651 )

          That would be nigh-impossible to do, given the set properties of any given material. Maybe a liquid filter that is adjustable could be done but then you're looking at something well beyond the reasonable expense of any grower, plus considerable complications.

      • A totally cold spot makes no sense in almost any house.

        It wouldn't appear "totally cold". It would seem empty (of heat sources), which is not the same thing.

    • I'm not sure how useful this stuff would be for that purpose. When the cops are conducting one of their we-don't-need-a-warrant-anybody-who-happened-to-be-carrying-a-10K-FLIR-scanner-down-this-public-road-could-have-seen-it... "non-searches", they aren't looking for reflected IR(that would be pointless, there is plenty of visible light around, and everybody knows where the house is), they are looking for IR emissions. Presumably, a house shielded with this stuff would react very oddly to IR light sources, b

  • Sigh, no (Score:5, Informative)

    by Ancient_Hacker ( 751168 ) on Sunday July 25, 2010 @06:59PM (#33024436)

    Calling these things "invisibility cloaks" is being very, very generous.

    They are fundamentally flawed in the specs: percent transmission, angle, bandwidth, and refraction.

    They're more of a laboratory curiosity than anything that would fool anybody.

    • Re: (Score:3, Funny)

      by drew30319 ( 828970 )
      You're right but Marketing shot down the name "fundamentally flawed."

      Didn't test well.

    • They're more of a laboratory curiosity than anything that would fool anybody.

      Yes but it is early days. Technology always starts out a bit crap, I mean your PC sure has come a long way from valves and punch cards.

    • If it hides you when people are not really looking carefully then you are invisible

      If when you are advancing towards a target it hides you for 30 seconds, then you are 30 seconds nearer than someone without it ... ...depends on your definition of fundamentally flawed

  • I can see the headline... (Score:5, Funny)

    by tiedyejeremy ( 559815 ) on Sunday July 25, 2010 @07:00PM (#33024440) Homepage Journal
    but can't see the story. What gives?

  • Does this really mean that visible light invisibility shielding is actually possible? Over the years, whenever I saw an article on this, I just yawned and assumed that the laws of physics wouldn't really allow someone to make a real device that could not be detected by some wavelengths of light.

    However, I'm going to assume that a practical real world application of the technology will require another tech called 'molecular manufacturing' as a prerequisite. I'm guessing that to cloak a macroscopic object f

    • Re: (Score:3, Insightful)

      by hedwards ( 940851 )
      Of course it's possible, it's just a question of whether or not we're ever able to do it effectively. For something to be invisible, you have to have the photons divert around it then converge at the other end as if they hadn't just diverted. That would make something invisible, the practice however is not easy by any reasonable stretch of the imagination.

      • Re: (Score:3, Interesting)

        by RsG ( 809189 )

        Infrared also poses additional problems above and beyond what you've stated, because the light isn't coming from an external source.

        Any hot object is going to radiate infrared radiation. That isn't something external being reflected off of it, that's coming from the surface of the radiating object itself. Infrared sensors work on contrast, so if you've got, say, a skin temperature object like a human being in a room temperature environment, it'll show up. Same applies for a room temperature object in an

        • Re: (Score:3, Informative)

          by Antidamage ( 1506489 )

          You're talking about thermal imaging. That's not how IR used for night-vision works. Your IR remote control doesn't shoot a jet of warmth at the TV. It's just a spectrum of light slightly outside of what we see.

          Actual IR cameras work so well for finding people because of what's REFLECTING the IR light. Synthetic materials reflect differently to the sorts of things you find in the wild. Additionally IR is useful for marking friendlies in such a way that people without IR gear can't see.

          Modern night-vision go

          • They were trying to use it in Afghanistan, but it wasn't really working very well. Mainly because of the caves. Ultimately it proved less useful than good old fashioned snitches.
  • Didn't they do this on Mythbusters?

  • Headline parsing (Score:5, Funny)

    by tux0r ( 604835 ) <magicfingers+slashdot@nOSPAm.gmail.com> on Sunday July 25, 2010 @07:23PM (#33024576) Homepage

    Glass Invisibility Cloak Shields Infrared

    You know you've been coding too much when the brain reads that as "noun noun noun noun noun" and throws a parse error expecting a verb...

  • Finally! (Score:1, Informative)

    by matunos ( 1587263 )

    When the Predators invade, we'll be ready!

  • This can bypass infrared security systems?

  • TSA screener: "nothing for me to see here, move her right along"

  • Thermal protection (Score:3, Interesting)

    by La Gris ( 531858 ) * <<lea.gris> <at> <noiraude.net>> on Sunday July 25, 2010 @08:33PM (#33024926) Homepage

    I know it is premature speculation on lab technologies but, well Infra-reds invisibility could mean improved heat isolating glasses windows for buildings. Keep visible light enter the building, let infra-reds refract though the other side and keep inside radiating heat bouncing the glass with perfect reflection. Would be a boon for vehicles where most windows face side to side. Would this be more efficient or combinable with athermic design?

  • No 'predator' tag?

  • what's that again? (Score:4, Informative)

    by martyb ( 196687 ) on Sunday July 25, 2010 @09:19PM (#33025118)
    Ok, I'm not up on materials science and had to look this up--thought others might be curious, too: chalcogenide glass [wikipedia.org]
  • Science needs to get working on my Gauntlets of Ogre Power.

  • I have to ask.. (Score:2, Insightful)

    by nanospook ( 521118 )
    Where does the heat go?

  • MTU is a lonely, lonely place...

  • you can't see a predator, but he shows up on infrared

    with this tech, you don't show up on infrared, but you can still be seen

    maybe this tech will finally allow for a lasting peace with the predator alien race via mutual incomprehension

  • Knew that already (Score:3, Interesting)

    by Drakkenmensch ( 1255800 ) on Monday July 26, 2010 @07:13AM (#33028126)
    Didn't the mythbusters already prove you can foil a heat-sensing alarm by holding a pane of glass in front of you?

  • Sweet (Score:2)

    by Xacid ( 560407 )

    Now we're set in case of Predator attack.

  • Cloaking uses metamaterials which have a negative refractive index- these bend light rays around the object being cloaked. Very recently, physicists and engineers realised that a similar principle can be applied to pressure waves caused by earthquakes. With the right design, the shockwaves might be bent around a building, rendering it "invisible" to an earthquake.

    This was previously thought impossible due to mistakes in some engineering research articles.
    Link here:
    http://www.sciencedaily.com/releases/2009/0 [sciencedaily.com]

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