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I What do physicist think about the orch theory which explains consiousness as a quantum

  1. Jan 11, 2017 #1
    Orch theory explains consiousness of human brain as a quantum related phenomenon. These quantum processes occur in microtubules. But at this temperature quantum computation is not possible. So what is the perspective of quantum physicists on this theory.
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  3. Jan 11, 2017 #2
    Link to peer reviewed paper??
  4. Jan 11, 2017 #3
  5. Jan 11, 2017 #4


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  6. Jan 11, 2017 #5
    The frequency with which this outdated paper still gets quoted is a clear demonstration of intellectual inertia of physicists regarding prematurely settled matters (recall von Neumann's faulty proof before Bohm and Bell). The origin of this inertia clearly has poisoned the well w.r.t. the subject.

    a) Shortly after this paper there was a reply to Tegmark in the same journal showing Tegmark was off himself by a considerable amount. https://arxiv.org/abs/quant-ph/0005025

    b) There have since been experimental demonstrations of quantum (biologic) effects taking place at room temperature:

    Coherent Spin Transfer Between Molecularly Bridged Quantum Dots - Ouyang et al 2003 http://science.sciencemag.org/content/301/5636/1074

    Efficiency in photosynthesis - Engel et al 2007 http://www.nature.com/nature/journal/v446/n7137/abs/nature05678.html

    Entanglement in bird retinae - Gauger et al 2011

    In-vitro demonstration of coherent effects in microtubules - Sahu et al 2013

    c) Last and perhaps least, Tegmark himself admitted in a debate in Oct 2013 that his theoretical criticisms of Orch OR in that paper weren't just numerically off but altogether somewhat premature given the direction both theory and experiment have moved since then

  7. Jan 11, 2017 #6
    Orch-OR is based on Roger Penrose's gravity-mediated objective collapse interpretation of QM, which isn't taken at all seriously by the larger physics community.
  8. Jan 11, 2017 #7


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    Orch theory does not explain consciousness of the human brain. It is a speculative hypothesis (actually hypotheses) that is more of an outline than anything else. I would not call it a theory because it doesn't really describe anything.

    The authors of the cited article (Hameroff & Penrose) mention it is "a particular proposal for an extension of current quantum mechanics...", and includes a novel version of quantum gravity as a component. If that isn't speculative physics on multiple levels, I don't know what is. I therefore question the suitability of the article for discussion.

    Obviously there is not one iota of experimental support for this hypothesis (which appears to require a dozen or more leaps of faith), nor does most of it represent generally accepted science.
  9. Jan 11, 2017 #8


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    There has been some previous discussion: https://www.physicsforums.com/threa...with-the-orch-or-consciousness-theory.783472/
    and more (Google search for "orch-or site:www.physicsforums.com" gets 30+ hits).

    Read these, and you will see that the answer to the question in the title of this thread is "not much". Without appropriate peer-reviewed papers and (even better!) relevant experimental results, there's not much more that we can say on the subject so this thread is closed.
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