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Quantum Entanglement, and Information.

  1. Apr 14, 2013 #1
    I'm not all that learned in Quantum Physics, but I read about this, and it piqued my interest.

    I read that the minimum speed that's been found for Quantum Entanglement, according to research done by Prof. Juan Yin and colleagues at the USTC in Shanghai, is 10 000c. This doesn't rule out the possibility of it being instantaneous, of course, but that's still mindblowing, even if it isn't.

    My question is as follows.

    Is it theoretically possible to transfer information via Entanglement, and, if it is, would it be possible to develop faster-than-light communication?


    Source: http://www.gizmag.com/quantum-entanglement-speed-10000-faster-light/26587/
  2. jcsd
  3. Apr 14, 2013 #2


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    It is not possible to transfer information through quantum entanglement. There are a number of previous threads on the subject in this subforum - a search with keyword "communication" might be good enough to find them.

    Be aware also that there are interpretations of quantum mechanics in which the phrase "the speed of quantum entanglement" is meaningless.
  4. May 1, 2013 #3
    I was also wondering about this issue and I think I've read every discussion on this forum on this topic but I still did't see one possibility studied: the information bit being transmitted on a lightSTREAM instead of a single partilcle.
    Suppose you have a setting of the double slit experiment on both transmitter(A) and receiver(B) side. Suppose you have a polirized lightstream of entangled particles send both ways. If you put a polirizer in fron of each slit on side A thus learning which one each particle got throuh, the wave functions of these will collapse, the wave pattern on the sreen will be gone and the same will happen on side B. So you can send a relatively slow stream of bits (buy measuring/not measuring on side A) but with 0 or negative!?! delay.
  5. May 1, 2013 #4
    You cannot control the measurement outcome - whatever measurement results you get on your A measurement is completely random.
  6. May 1, 2013 #5


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    Everything we know today says it’s impossible.

    I played with the thought to see if I could find a crack in the “no-communication wall”. But good old Einstein is still rigorous on the “FTL Bookkeeping”. :smile:

    What’s wrong with this EPR-Bell FTL Gedankenexperiment?
  7. May 1, 2013 #6


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    It doesn’t work. This guy had the same idea, starts 25 min into the video:

    Last edited by a moderator: Sep 25, 2014
  8. May 1, 2013 #7


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    That is absolutely correct. However, if we could determine which one (of A & B) decohere the entanglement, it would (at least in principle) be possible to send a signal from Bob to Alice.

    But Einstein is not too fond of this idea... ;)
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