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Nonlocality of a Single Particle: A Scheme Without Objections

  1. Nov 10, 2007 #1

    Ivan Seeking

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    http://www.physorg.com/news113824784.html
     
  2. jcsd
  3. Nov 10, 2007 #2

    ZapperZ

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    The "demonstrated" part is a bit misleading. All they did was to reformulate the Hardy criteria that did not have the part that GHZ objected to. We still have to wait for an experiment using such a scheme.

    Zz.
     
  4. Nov 10, 2007 #3

    Ivan Seeking

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    Sure enough! The title and a quick read led me to think they had actually done the experiment. I'll change the word "demonstrated" to "scheme".
     
  5. Nov 10, 2007 #4

    DrChinese

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    A minor quibble: This demonstrates "non-locality" no more - and no less - than traditional Bell tests with entangled particles. The issue, as is well known, is that such experiments show that either locality OR realism must be rejected to match the predictions of QM. It does not say which of these two must go. The title of the article could have been "Non-Realism of a Single Particle" just as easily - and just as accurately.
     
  6. Nov 11, 2007 #5

    Ivan Seeking

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    Okay, but I'm not changing the title again. :biggrin:
     
  7. Nov 11, 2007 #6
    That's a bit superfluous: I don't think many physicists will contemplate abandoning realism at this stage. (Heck, could I even speak of other physicists if I did?)

    Very interesting claim, that entanglement is just superposition (a classical wave effect.. basically reduces most of "the mystery" to ol' Fourier math), I'm keen to see how this is received (particular by Zeilinger et al).
     
  8. Nov 12, 2007 #7
    Just like all the other experiments of this type it "proves" non-locality (or non-realism) only if other, supplementary assumption is hold true. One must assume that the particles' properties, as they leave the source, are not influenced by the presence of the experimental setup (prism, detectors, Alice & Bob, etc). This is hardly an acceptable hypothesis.
     
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