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Space-Time Cloak Could Hide Actual Events

Posted by samzenpus on from the out-of-sight-out-of-time dept.

An anonymous reader writes "My first thought was, a hypothetical space-time invisibility cloak? That must be what hypothetical crime-fighting Einstein wears when he wades into the fray! Sadly, the researchers who thought up this trick to 'hide events' say that the metamaterials we have on hand will only allow for a nanoscale demonstration at best."

4 of 129 comments (clear)

  1. Re: post by ArsenneLupin · · Score: 2, Informative
    Congrats :-)

    I tried the same thing, but I must have broken one of my many mirrors...

  2. Re:Hiding things? Isn't that the point of invisibl by Jojoba86 · · Score: 2, Informative
    Clicking through to the CNN article tells us:

    "A safe cracker would be able, for a brief time, to enter a scene, open the safe, remove its contents, close the door and exit the scene, whilst the record of a surveillance camera apparently showed that the safe door was closed all the time,"

    So it's a way of hiding something in time, without anyone really knowing anything is being hidden.

  3. Better article by ath1901 · · Score: 4, Informative

    I found another article about the article which makes more sense: http://physicsworld.com/cws/article/news/44320

    There is a chicken and car analogy that should appeal to the crowd here:

    An analogy, says McCall, is a chicken crossing a busy road. Once the chicken steps onto the road cars must stop to let it pass, but as soon as it leaves the other side the cars would accelerate to catch up with the traffic ahead. To an observer farther down the road, the stream of passing cars would display no evidence of having slowed down.

    So, there is no magical disappearing of time or events or 4D cloaking of spacetime. That's just bullshit from some journalist who doesn't understand what spacetime or 4D means... Not more than a recorded tv program is cloaking space time.

    1. Re:Better article by ath1901 · · Score: 4, Informative

      Ok, so here's my personal rant:
      Why are all the non-linear optics experiments ALWAYS misinterpreted as having something to do with spacetime or relativity?

      A optical black hole is NOT a black hole. It's a piece of glass. Radiation from such an optical black hole is NOT Hawking radiation . It just happens to have the same explanation.

      Just because light in a vacuum "happens" to travel at the fastest possible speed ("the speed of light" = c) doesn't mean that when light is slowed down, the maximum speed is somehow slowed down. Spacetime is completely unaffected by the bending/stretching/slowing down of light. You CAN travel faster than the speed of light in a piece of glass but you CAN NOT travel faster than the theoretical speed limit known as "the speed of light" / c.

      Light isn't special. It is just another particle (photons). It doesn't affect spacetime in any way except by the gravitational force which happens to be tiny since it is so light (pun not intended).