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Hardy's Paradox - Which Way Information

  1. Aug 3, 2013 #1
    I have three quick questions regarding the experimental set-up attached, in relation to Hardy’s Paradox.

    What possible detections are available, according to Quantum Mechanics, and do those detections indicate, for the electron and the positron, which path they took? I’m guessing not as at the beam splitters, there is ½ probability of being reflected and ½ probability of being transmitted. In accord with QM, are they are in a superposition, after the beam splitter, as being both reflected and transmitted?

    Because the particles in question are in a superposition of being in both paths (e+ in a superposition of paths u+ and w+/u+, and e- in a superposition of paths v- and w-/u-), they’re strictly not ‘real’ (this is where the realism refutation comes about, in standard QM), thus the particles cannot interact and annihilate?

    Attached Files:

  2. jcsd
  3. Aug 5, 2013 #2
    that stuff can happen only if the wavefunction collapse is instantaneous.
    Last edited: Aug 5, 2013
  4. Aug 8, 2013 #3
    work in progress
    "We find that it is possible to discriminate between the scenarios of instantaneous collapse and finite-time reduction via a large number of double measurements of polarization. The quantities to be recorded would present distinct behaviors in each scenario, the deviations being small but distinguishable from pure statistical fluctuations"
  5. Aug 8, 2013 #4


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    First draft looks pretty nice, audioloop.
  6. Aug 8, 2013 #5
    It would seem from that paper that instantaneous collapse is compatible with QM - than time-finite collapse - by looking at the two tables they provide results in.
  7. Aug 8, 2013 #6
    Indeed. has profund implications.
  8. Aug 8, 2013 #7
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