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How To Cloak Objects At a Distance

Posted by samzenpus on from the can-you-see-me-now dept.

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."

3 of 136 comments (clear)

  1. Re:Wow smart scientists... by Emb3rz · · Score: 4, Insightful

    Think about it in terms of bitmasks...

    Background   = 00110000
    UncloakedObj = 11100000
    CloakedObj   = 00001100

    CloakShows   = 11110000

  2. If you give it some thought by Dunbal · · Score: 5, Insightful

    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.

    --
    Seven puppies were harmed during the making of this post.
    1. Re:If you give it some thought by JustinOpinion · · Score: 4, Insightful

      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.