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Invisibility Update

  1. May 25, 2006 #1
    This article is pretty neat. It talks about creating an invisibility "cloak" that works by bending light around things through the use of "metamaterials". Apparently this wouldn't be all that hard to do for making things invisible to RADAR waves (i.e. creating an invisibility "cloak" that, although it doesn't make things invisible to the naked eye, DOES make them invisible to radar) since radar waveslengths are measured in millimeters.
    The problem with doing the same thing for visible light is that visible light is measured in nanometers, and at those short wavelengths you'd have to be able to manufacture and control the materials from which the "cloak" is made at nanometer scales.

    Here's the link to the article:


    (Be sure to click on the link in that article to the "loophole" they're talking about as well)

    I DO think a correction needs to be made to what this article says about using this particular "loophole" to get around the fact that light being bent around something takes a longer path.

    My understanding of that particular little "loophole" is that although the peak pulse of a light beam can be shifted forward, there by giving the APPEARANCE of THE PEAK PULSE of the light beam traveling at FTL speeds, the transmission of ANY form of *information* is *still* limited to the speed of light in a vacuum.

    I.e. Einstein's "causality" has not yet been disproven, and to date there's still no reason to suspect it can be.

    That, at least to my little layman's brain says, that if a bird flew behind an invisibility cloak like the one described here, there'd still be distortions visible due to some parts of the image the cloak passes to your eyes taking a longer path to your eye than others.

    Regardless, I thought it was a hell of an interesting idea.

  2. jcsd
  3. May 25, 2006 #2
    They had a similar article on the BBC web site. And, the impression I got was the light would have to be manipulated in such a way that it doesn't scatter. They pointed out that un-like water [that will wrap around an object], light [photons] tend to go in various directions when coming in contact with an object. Even with this issue sorted out, I would think a side view would appear like a optical distortion with increased distortion around the circumference.
  4. May 25, 2006 #3
    I wonder if it would possible to see this being used in Iraq. Just think about those insurgents having to worry about invisble americans.
  5. May 25, 2006 #4
    "I wonder if it would possible to see this being used in Iraq. Just think about those insurgents having to worry about invisble americans."

    Heh. Are you kiddin'? As if we don't have enough problems already. Picture it for just a moment...

    Loose the keys to your car?
    Invisible americans must have taken them!

    Where's your homework?
    Invisible americans stole it!

    The electricity substation blew up again?
    Invisible americans must have done it!

    The gas in your cab was siphoned off last night?
    Invisible americans!

    Look! The candle on the table just flickered!
    Invisible americans!

    Who used the last of the tea?
    Invisible americans!

    Oh no! The cat's pregnant!

    Meanwhile, back in the good 'ol US of A where people are more "sensible" we'd have...

    Democrats convinced Invisible Republicans are rigging votes.

    Republicans convinced Invisible Democrats are rigging votes.

    The "Black Helicopter" crowd would be going out of their already loosely tethered minds.

    There'd be headline banners in every tabloid about Invisible Baby snatching rings.

    And, just to prove that some things are universal regardless of where you grow up....

    "Billy? Where's you physics report on Metamaterials?"
    "Umm, ah, INVISIBLE TERRORISTS SOLE IT! They did! I swear!"

    Maybe this whole "invisible cloak" thing is just a bad idea no matter how you slice it.
    Last edited: May 25, 2006
  6. May 26, 2006 #5


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    INVISIBLE BABIES????? :bugeye: :eek:

    Loose the keys to your car?
    Invisible babies must have taken them!

    Where's your homework?
    Invisible babies took it!

    The electricity substation bleu up again?
    INVISIBLE BABIES@!!! :surprised :surprised :surprised
  7. Nov 12, 2006 #6


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    Gold Member

    first we've got to figure out how to do it. then we can think about what to use it for.
  8. Apr 4, 2007 #7


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    Gold Member

    then again,
    thats what they did with the nuclear bomb (besides winning the war)
    and look at the way how nuclear weapons are being restricted to this day.
    (of course excluding North Korea's actions.)
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