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Science Technology

How To Cloak Objects At a Distance 136

KentuckyFC writes "All invisibility cloaks to date work by hiding an object embedded inside them. Now a group of physicists have worked out how to remotely cloak objects that sit outside a cloaking material. The trick is to make the cloaking material with optical properties that are exactly complementary to the space outside them. Complementary means that the material reverses the effect the space has on a plane wave of light passing through it. To an observer this space would appear to vanish. The scientists say that to cloak an object sitting outside the cloaking material, first measure its optical properties and then embed a "complementary image" of the object within the cloak. So a plane wave is first distorted by the object but then restored to a plane by the complementary image of the object within the cloak (abstract). An observer sees nothing. This method has another benefit. Objects hidden in conventional cloaks are blinded because no light enters the cloaked region. But objects that are remotely cloaked like this should still be able to see their surroundings."
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How To Cloak Objects At a Distance

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  • by Emb3rz ( 1210286 ) on Thursday November 06, 2008 @09:15AM (#25659821) Homepage
    Think about it in terms of bitmasks...

    Background   = 00110000
    UncloakedObj = 11100000
    CloakedObj   = 00001100

    CloakShows   = 11110000
  • by Dunbal ( 464142 ) on Thursday November 06, 2008 @09:35AM (#25660027)

    This technology, if adopted by the military, will probably only be useful against civilians. Against another sophisticated military there will always be a way to detect what you're trying to hide through other means than visible light - magnetism/alterations in the earth's magnetic field (in the case of big chunks of metal, heat), RF emissions, overhead imaging, radar, sonar, etc.

    You won't be able to hide your tank like this, but the small laser turrets to keep the neighbor's cat off the lawn might work... now if only those sharks would stop swimming.

  • by andy19 ( 1250844 ) on Thursday November 06, 2008 @09:41AM (#25660071)
    As much as I love the Father Ted reference, that really doesn't have anything to do with this article.
  • by JustinOpinion ( 1246824 ) on Thursday November 06, 2008 @10:58AM (#25661017)

    I'm not so sure about that. I mean, the military currently uses a whole bunch of stealth technology against their enemies: everything from simple paint color and camouflage, to radar-reflective stealth paint or ultra-quiet engines for submarines. None of these are perfect, but all are useful.

    You may not be able to make yourself 100% invisible to an enemy that has good tech, but as long as you can give yourself an advantage in hiding, it's worth using. The "advantage" could be increased survival (enemy hit accuracy is reduced), better range (you can get closer before being detected), or maybe just the cost to the enemy for them to launch all the overhead imaging and use all magnetic field sensing equipment you just mentioned.

    If cloaking became viable, it would definitely be used by the military against other high-tech enemies. In battle, every advantage counts.

  • by Culture20 ( 968837 ) on Thursday November 06, 2008 @11:01AM (#25661059)

    This technology, if adopted by the military, will probably only be useful against civilians.

    Or unsophisticated military. Against other sophisticated military, it's good to have the tech first because that allows research into counter-tech sooner. One way to beat the enemy is to force them to spend too much in resources keeping a stalemate.

  • by db10 ( 740174 ) on Thursday November 06, 2008 @11:54AM (#25661959)
    It's not the masking that's the problem, it's filling in the mask dynamically.
  • Re:Yawn (Score:2, Insightful)

    by jebrew ( 1101907 ) on Thursday November 06, 2008 @12:28PM (#25662541)
    I dunno, they've got a good point. If no light is getting in to the object being cloaked, then it's not just invisible, it's blind...so while you wouldn't see much in the Sorority Girls' dorm, you could have loads of laughs feeling up anything that crossed your path.
  • by dreamchaser ( 49529 ) on Thursday November 06, 2008 @03:06PM (#25664945) Homepage Journal

    You obviously haven't given it much thought. If your logic held true, there would also have been no reason to develop stealth technology for our aircraft. As someone else astutely pointed out in response to you, every advantage helps. There would be many, many applications for 'cloaking' technology against even high tech militaries.

    Of course, it's fashionable around here to say will really only be useful when used against civilians.

  • by wasted ( 94866 ) on Thursday November 06, 2008 @10:54PM (#25670847)

    People mod that up funny, but it's actually insightful as to how the school system doesn't work for everyone, and how thinking outside of the box is so frowned upon when everyone should do their utmost to encourage it.

    It's not just the school systems that frown upon non-standard answers, it's the majority of society. In many situations, propose an idea even slightly outside of the predominant group-think, and watch how many folks start to get offended/shoot it down without thought.

    For example - I had a boss write a simple VB app that cut the time needed for his subordinates to do a specific task by at least 50% every time, sometimes as much as 80%, while improving the quality of the output. His boss shot it down and prohibited its use because my boss wasn't assigned to write software, and they had paid someone else to write less-effective software that used more bandwidth and provided a lower quality output.

    In another case, we had a door clearance problem in a customer area due to carpet installation. Funding for a new door wasn't forthcoming, so a couple of us on the late shift lowered the false floor just enough to regain clearance. We didn't think much of it, since it solved the problem without needing any funding. However, that solution got a lot more attention (both negative and positive) than we expected. All of the regular visitors noticed. Some folks thought it was a great idea. Those responsible for the building bristled at the idea of a non-standard solution when we suggested it (after the fact, and played it off as a joke when we saw their response), so we had to tell them we bought a new door out of our own funds. (I guess spending hundreds of dollars on a new door is more acceptable than a few radians of rotation of a few large bolts in their eyes.)

    Despite all of the feel-good seminars, I believe people in general still aren't accepting of ideas outside of their limited fields-of-view. If I recall correctly, in Japan, there is a saying that roughly translates to "The nail that sticks up is hammered down." Although U.S, citizens like to say that the saying does not apply to them, and individuality is encouraged, I think that the saying is applicable in many U.S. situations as well.

    I hope that most reading this work for those without such a limited field of view. It is so much more enjoyable to go to work with bosses that encourage thinking.

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