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Instantanious Communication possible?

  1. Feb 27, 2010 #1
    Quantum entanglement

    Could somone explain to me the following questions please?

    Is it possible for instantaneous communication to occur using entangled particles?.
    i have heard that it cannot be done because you are not allowed to know information about both the position and the speed of a particle at the same time, however do you really need to know them both?.i have heard the argument If I measure the spin of an entangled electron, yes it communicates the value somehow to its twin — but I can’t use it. I had no idea what the spin was going to be but if that is the case then how did we prove that Quantum entanglement exists?

    if one particle is stimulated as long as you can detect a wobble on the other particle could that be enough to make it work? if not why not!

    how can a particle communicate instantaniously with another no matter how far they are appart when we know there is no absolute time in the universe?

    if anyone can enlighten me on these questions i would be very greatfull

    thankyou everyone for all of your input much appreciated
    Last edited: Feb 27, 2010
  2. jcsd
  3. Feb 27, 2010 #2


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    The reason instantaneous communication is impossible by the method you suggest is that "passive" observation of a quantum system is impossible. You must actively measure a quantum system to observe it. Under these circumstances, it is impossible for a potential receiver of such a message to know if the "wobble" she sees upon measuring her side of the entangled pair was imbued by some putative sender's action, or by her own act of measurement. In order to be sure, she would need to receive a "normal" (I.e. slower than light) message to tell the difference.
  4. Feb 27, 2010 #3
    @Rob060870: I'm asking this for my own academic interest, but would you mind telling me if it was the game 'Mass Effect 2' which prompted you to ask this question? I've noted a sudden surge of interest in the topic in some areas (here less than others), and I think the two coincide.
  5. Feb 27, 2010 #4


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    Welcome to PhysicsForums, Rob060870!

    There are a series of tests that can be done to show quantum entanglement. For spin/polarization, you demonstrate the so-called "perfect" correlations on a pair of entangled particles. Unentangled particles do not show such statistics with rotational invariance (i.e. at any angle setting).
  6. Feb 27, 2010 #5
    Hello i have never played Mass Effect2 so that was not the reason why i asked that question. when reading about entanglement it sounds so amazing that the pair of particles can communicate instantaniously i was thinking of controlling a mars rover with no time lag!.
    thanks for your interest.
  7. Feb 27, 2010 #6
    thankyou for explaining that for me.
    much appreciated.
  8. Feb 27, 2010 #7
    Thankyou for your reply, i will have to read more on the subject.
  9. Feb 27, 2010 #8
    thankyou for taking the time to explain this to me, its a shame that we cannot have instantanious communication by this method.
  10. Feb 27, 2010 #9
    thankyou for explaining that for me, i have had a really good response to this question.
  11. Feb 27, 2010 #10
    Thanks very much for answering Rob! I'm just trying to keep track for my own benefit. I can see why the dream of no lag between a rover and earth would be so desirable... alas 'c' strikes again. :wink:
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