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Entanglement and Time

  1. Jan 29, 2009 #1
    Hi guys,
    I am curious about the work done by Antoine Suarez. I think this is a famous one but I need some more information about this. He concluded :

    ----------------------------------------------------------------------
    The final results

    The final results of the experiments with moving measuring devices (see experiments) rule out the possibility to describe the quantum correlations by means of real clocks, in terms of "before" and "after"; nonlocal quantum phenomena cannot be described with the notions of space and time. This means that there is no time ordering behind nonlocal correlations, so the causal order cannot be reduced to the temporal one. Quantum correlations somehow reveal dependence between the events, or logical order. Experiment shows that this dependence, or logical order, is beyond any real time ordering. In the realm of the nonlocal quantum phenomena, things come to pass but the time doesn't seem to pass here.
    ------------------------------------------------------------------

    Is there any critics to this conclusion and his experiment?
    Or are we finally concluded that there is no time ordering behind entanglement?
    What happened to The interpretation that information is sent backwards in time - is it dead?

    Thanks in advance...
     
  2. jcsd
  3. Jan 29, 2009 #2

    JesseM

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  4. Jan 29, 2009 #3
  5. Jan 29, 2009 #4
    anyone??? sorry, I am little bit impatient person in nature:)
     
  6. Jan 30, 2009 #5
    Cause and effect seems to be fundamental AFIK and can be viewed to account for special relativity properties of space. That needs time ordering, I would suggest - at least in 3 space.

    Entanglement implies an instant time connection between the particles involved. The connection can be instant in 3 space, because it does not break cause and effect, implying no apparent distance in the configuration space, or at least, no recognition of distance. Contradiction? Well, like function(1) = function(2) does not need time to be true when time is not specified.
     
    Last edited: Jan 30, 2009
  7. Jan 30, 2009 #6

    jambaugh

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    No!
    Entanglement is a priori statistical correlation and not a causal connection be it instantaneous or not. We just see that quantum systems can correlate more strongly than classical. This research is supporting that interpretation.

    The mistake one makes is in believing the wave-function is something "out there" instead of a representation of our knowledge of a quantum system. This leads to thinking that because we update the wave function of one half of an entangled pair when we measure the other that some mysterious effect is being transmitted.

    As with "collapse" the "effect" is that we have new info about the system and so we update our representation. Hence the logical ordering described.
     
  8. Jan 30, 2009 #7
     
  9. Jan 30, 2009 #8
    I agree with debra's and jambaugh's comments.

    From the papers and website I looked at, Suarez seems to be trying to interpret the results of the "before-before experiment" as supporting the idea of an omnipotent and omniscient being. Some sort of "immaterial" force for "free will" outside of space and time.
     
  10. Jan 31, 2009 #9
    Thanks for your response guys...
    If info is not being exchanged between entangled particles, I am curious how this transportation thing works? As far as I know they even made molecular transportation possible. I have always thought transportation is only possible if info is exchanged between entangled particles, no?
     
  11. Jan 31, 2009 #10
    What "transportation thing"?
     
  12. Jan 31, 2009 #11
    I meant teleportation...God!:) my mistake...
     
  13. Jan 31, 2009 #12

    jambaugh

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    Pardon me debra,
    I didn't read carefully enough seeing the "instant time connection" as an assumption of instantaneous causal connection. My bad.
     
  14. Feb 5, 2009 #13
    Suarez has an agenda that you might characterize as religious, but it's nothing secret, and while it bothered me at first I've adjusted to it. He certainly pushes "free will" (cf. his debate with 't Hooft) and describes it as a quantum influence outside of space and time. But he's a good physicist and has worked with the best (Gisin, Zeilinger) so, whatever keeps him motivated.

    If you think of an entangled system as entirely physical, from the standpoint of the "separate" particles there really is no separation between them, no matter how great the distances measured. Anton Zeilinger says entanglement appears to conduct its business "outside space and time" although he's being practical, not so much mystical. From a classical perspective the before-before experiment raises issues but then in QM what doesn't?
     
  15. Feb 5, 2009 #14
    I agree with Zeilinger. And there does not seem to be a shared space that all wave functions/ particles can address from all real-space coordinates (ie all localities) in physics at present. It would solve a lot of issues, especially our problem in this thread with entanglement.
     
  16. Feb 5, 2009 #15
    Oh, no... That mysterious "knowledge" again...
    Dont try to bring the rotting corpse of the Copenhagen interpretation here :)
     
  17. Feb 5, 2009 #16
    Oh. You mean this kind of thing:

    "It is wrong to think that the task of physics is to find out how Nature is. Physics concerns what we can say about Nature."

    "It from Bit."

    "When investigating various interpretations of quantum mechanics one notices that each interpretation contains an element which escapes a complete and full description. This element is always associated with the stochasticity of the individual event in the quantum measurement process. It appears that the implications of this limit to any description of the world has not been sufficiently appreciated with notable exceptions of, for example, Heisenberg, Pauli and Wheeler. If we assume that a deeper foundation of quantum mechanics is possible, the question arises which features such a philosophical foundation might have. It is suggested that the objective randomness of the individual quantum event is a necessity of a description of the world in view of the significant influence the observer in quantum mechanics has. It is also suggested that the austerity of the Copenhagen interpretation should serve as a guiding principle in a search for deeper understanding."

    "An elementary quantum system contains one bit of information."

    :-|
     
    Last edited: Feb 5, 2009
  18. Feb 5, 2009 #17
    I would agree with the Zeilinger quote above. If I was modelling a quantum behaved particle in a computer I would use the CI equations to do it and some space time parameters. It would behave as the real particle does and give accurate results that agree with experiment.
     
  19. Feb 6, 2009 #18
    Could you show me these specific 'CI equations' which are not part of QM, please?
    Hint: CI, MW and TI are in agreement with the experiment. That is why they are called different 'interpretations' of a theory, not different theories.
     
  20. Feb 6, 2009 #19
    The "rotting corpse" you refer to is still the standard framework that almost all progress within the field has been composed in. Why do you have such vitriol for it, despite its excellent predictive power and economy on metaphysical suppositions? QM has introduced a wide range of counter-intuitive concepts that do not behave according to classical mechanical principles, why should the nature of the wavefunction obey something similar to classical wave mechanics? I understand the desire to return to a deterministic worldview, however, the physics strongly suggest that nature is probalistic. All other interpretations just scramble to find ways to manufacture Copenhagen's predictive power and empirical success, but add nothing but metaphysical layers of complexity. The Copenhagen Interpretation is still the dominant pardigm in physics, and has been a standard that alternative interpretations try to meet. It is certainly not a corpse, particularly with the conceptual clarifications of consistent histories.
     
  21. Feb 6, 2009 #20
    Oh I see, you are angry and sarcastic because you are not a CI supporter.

    MWI? I am not sure even David Deutsch follows that any more.

    Bohm and his pilot waves? Does not conform to SR among other problems with it.

    Super Determinism - cannot argue with that (except with a little logic).

    CI is just the minimum mathematics that works and probably the best we have got at present - a stepping stone at least - a physical interpretation of some aspects of it should follow.

    If you can argue differently, go ahead, no obfuscation though....
     
    Last edited: Feb 6, 2009
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