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Two places at once

  1. Oct 18, 2006 #1
    Recently I became aware that in a controlled laboratory experiment one particle can be seen in two places at once. This has opened a door in my mind and I can't stop thinking about this. My question is, can anyone give me more information about this topic, or point me in the direction to find more info?
     
  2. jcsd
  3. Oct 18, 2006 #2
    It sounds like you've been led up the garden path by 'popular culture' references to quantum mechanics.

    What QM does is state that particle's positions are not precisely defined. In effect, a particle isn't anywhere in particular until you catch it in a certain position. When you're shooting particle beams about, a particular particle can turn up anywhere - it's just overwhelmingly likely that it'll turn up somewhere very near the straight line through space you'd expect the beam to follow.
     
  4. Oct 18, 2006 #3
    From what I understand, the particle will act irrationally, and be in infinite places on the probability field (as stated above, a higher concentration where it is expected to be). The one thing that stops the erratic behavior is the simple act of observing it. Observing the particle makes it "make a decision" and end up at one point in the probability field.
     
  5. Oct 20, 2006 #4
    This kind of statement very much adheres to the garden path.

    And how can a particle possibly act irrationally?
     
  6. Oct 22, 2006 #5
    that is so weird i just was flipping through a book about this, it says that when not seen the "matter" is in every possible place it can be but when seen it is in one place, to quote, "When unobserved matter is a wave when observed matter is a point" So the point is that you can't think of matter as a thing, acording to quantum physics matter is the possiblities of conciousness:surprised
     
  7. Oct 23, 2006 #6

    Ivan Seeking

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    http://newton.ex.ac.uk/aip/physnews.626.html

    http://www.discover.com/issues/jun-05/cover/
     
  8. Oct 23, 2006 #7
    No, according to quantum physics matter/particles are quantas (= pieces, lumps) of energy of the quantum field(s).
    The consciousness aspect is humbug and is only related to the Copenhagen interpretation that can be shown to be unphysical (since Copenhagen interpretation, by its own definition, doesn't tell anything about reality).
     
  9. Oct 23, 2006 #8

    Ivan Seeking

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    I agree that the language used was misleading, but to say that it is all humbug seems premature since we don't even know what consciousness is yet.

    And I know that people are writing papers on the subject, eg.

    http://arxiv.org/ftp/quant-ph/papers/0208/0208068.pdf

    http://scholar.google.com/url?q=http://cogprints.ecs.soton.ac.uk/archive/00002827/01/SpinNature.pdf

    http://scholar.google.com/url?q=http://cogprints.ecs.soton.ac.uk/archive/00002579/01/SpinMind2.pdf
     
  10. Oct 23, 2006 #9

    selfAdjoint

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    Ivan, all these papers seem to describe their hypotheses as theories. That confusuion is perhaps forgiveable in the popular press but I find it hard to take it seriously on a presumeably scientific venue like the arxiv.

    It is one thing to assert a spin-mediated theory of consciusness, it is another to give even the slightest evidence of it's being true, or even cogent.

    I guess what I'm saying is that it's up to someone (you? the authors?) to show me that "it's not all bunk".

    And in view of the -- um -- innocence of the OP post, and the nature of this forum, it seems a bit much to present this speculation as evidence that QM has anything to do with consciousness.
     
    Last edited: Oct 23, 2006
  11. Oct 23, 2006 #10

    Ivan Seeking

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    I'm not promoting any particular position or theory, but this is not all Copenhagen, and papers are being written on the subject by respectable scientists. What I am saying is that we can't rule out QM as the key to understanding consciousness. In fact, it gets a little hard to imagine how it could not be uniquely a QM phenomenon.
     
    Last edited: Oct 23, 2006
  12. Oct 23, 2006 #11

    selfAdjoint

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    The implications of that reply are surely better exposed on the philosophy forums, where duelling individual's "hard to imagine"s are acceptable. Please Ivan, don't try to import that discussional ethic here. We have enough trouble with cranks who can do the math!:biggrin:
     
  13. Oct 24, 2006 #12

    Ivan Seeking

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    Selective quote - that wasn't the basis for my post. Are you saying that the study of consciousness is by defintion unrelated to QM? The authors of the papers seemed credible enough.

    I should add that my first exposure to this discussion was in quantum mechanics. In short, what I got from it was the consciousness is a problem for physicists, not philosophers.
     
    Last edited: Oct 24, 2006
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