Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

QM and free will

  1. Feb 20, 2004 #1
    can these things go together, for me - how can one have free will without excerising the abliity to use there will in actions, that not to say that all actions thus are a result of ones will, for example other peoples might interfere, or even other events, but there seems that on some level and does not need to be universal some form of determinsim is required, unless anyone has any ideas how this might not be the case, please present them!!!

    So the universe might not hold to cause and effect of determisn, however on some level cause and effect does exist in a local fashion this might be an result of a habit has hume said, or maybe how our minds etc actually can effect reality?

    the question I am asking.. is does QM or any other phyiscs at presnt dis regard the possiblity of free will?
  2. jcsd
  3. Feb 20, 2004 #2
    That is conceivable. There was a recent paper from a well known physicist, expert in Quantum Mechanics, Bernard d'Espagnat: Consciousness and the Wigner's friend problem where the inherent QM indeterminacy is proposed as the leverage by which the consciousness may affect physical reality. Another well known physicist and a QM expert speculating along the similar lines is Henry P. Stapp, e.g. in paper Quantum theory and the role of mind in nature. While I don't personally agree with either, it is a possibility.
  4. Feb 20, 2004 #3
    Free will and predestination are relative concepts. They only apply to things existing within time. Furthermore, We know that for anything to be "predesined" there must be a "predestiner." Basically, the microcosm (spiritual reality) has absolute free will and the macrocosm (physicsal matter and time) are absolutely predestined. This explains astrology, i-ching, tarot cards, runes, etc.

    The Hiesenberg uncertainty principle implies that the cosmos in not totally deterministic. A;lthough even complete chaos is a flavor of complete determinism. It isn't that either.
  5. Feb 21, 2004 #4
    No it doesn't imply indeterminism since it is a property of Fourier transforms valid for any wave theory (such as classical electrodynamics, a perfectly deterministic theory). In the early years of QM, the HUP was informally thought to imply indeterminism but Einstein's and Schroedinger's critique (based on entangled states) has made such interpretation of HUP untennable.

    Subsequently, it was believed for couple decades that von Neumann's proof (1932) of impossibility of Hidden Variables shows fundamental indeterminism of QM. That proof was found inadequate in early 1950s when Bohm created deterministic theory which reproduced all predictions of conventional Quantum Mechanics, providing a direct counterexample to von Neumann's proof. Another proof, seemingly stronger was produced by Kochen & Specker, but that one was inadequate as well.

    In early 1960s, J.S. Bell came up with a weaker substitute for von Neumann's & Kochen-Specker's HV impossibility proofs. Bell's proof claimed to demonstrate impossibility of a local deterministic theories only (but it allows for non-local deterministic theories). The experiments so far, after over three decades of attempts, haven't been able to establish the violation of Bell's inequalities (which would indicate impossibility of local deterministic theories). Another thread ***EPR Experiment with Pool Balls*** has much more details and links on this topic.
    Last edited: Feb 21, 2004
  6. Feb 21, 2004 #5
    "free will"

    Bells theorum implies particle wisdom. This seems to imply a "free will" choice. On the last page of this thread is more info.
  7. Feb 21, 2004 #6


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    Re: "free will"

    No, Bell's theorem and the subsequent experiments do not imply particle wisdom. The quantum mechanical concept of the entangled state is perfectly clear and doesn't require either particle to "know" about the other. If you separate a pair of gloves, and send one to each of two separated friends, then the one who receives the left handed glove can conclude that the other friend received the right handed glove. Do the gloves "know" about each other? Rather the information inheres in the set-up of the experiment, just as Bohr claimed against Einstein.

    On the other hand d'Espagnat's paper, linked by nightlight above, does assume particle consciousness, or rather concludes it on the basis of a careful analysis of the Wigner's friend thought experiment. Each quantum thingy is supposed to have a little bit of consciousness, but being quantum that consciousness is not predictive. But with many particles comes decoherence, and some kind of mean field predictiveness that is much more accurate, and thus to us. Read the whole thing
    Last edited: Feb 21, 2004
  8. Feb 21, 2004 #7
    something missing

    For some reason the server of nightlight denies me acces to the sites that are linked from this part of the world. Could that info be linked another way so i could read it.

    I have been thinking about this paradox for some time. You know the experiment with polarized light using three filters. How can a photon pass through a vertical filter, diagonal filter horizontal filter in line? According to QM diagonally polarized light, is not a mixture of horizontally polarized light, or vertically polarized light. How can we say that the horizontal components of diagonally polarized light passed through the horizontal polarizer and the vertical components of the diagonally polarized light passed through the vertical polarizer? According to QM, diagonally polarized light is a seperate thing in itself. How can a seperate thing in itself get through all three filters but not through two? Is light, particle or wave or something else? How can a photon be broken down into horizontal polarized component or vertical polarized component? It should not be possible. The paradox seems to be, the difference between quantum logic and classical logic. Could it be, because, our thought processes, are following the laws of classical logic? Do what we see, we know to be impossible. Polarization of light is one way or another. We are in effect, ignorant of the fact what is seen. Experience does not follow the rules of classical logic, it follows quantum logic. Nothing is either this or that in quantum logic or the realm of experience, it is much more.

    Maybe light that is wave or particle is neither wave or particle, we just think it is and is just "quantas", Could not then that third possibilty, of not either or be the "free will choice"

    Let me know if this seems at all coherent? This topic is way out of my ballpark but is of utmost interest to me.
    I have just found thïs. http://www.poco.phy.cam.ac.uk/~mjd1014/stappr.html [Broken]
    Last edited by a moderator: May 1, 2017
  9. Feb 21, 2004 #8


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    Rader, on getting d'Espagnat's paper, it is quant-ph/0402121 on the preprint arxiv, http://arxiv.org, [Broken] perhaps you have a mirror site?

    On the polarization question, the z-direction polarization would be charaterized by a photon state (0,0,1), the y-direction by (0,1,0), and the 45 degree orientation by [tex] (\surd{2}, \surd{2}, 0)[/tex]. Together with the rules for adding angular momentum, this should give the classic polarization results.
    Last edited by a moderator: May 1, 2017
  10. Feb 28, 2004 #9
    Flying a kite here. Is this right or wrong?

    In regard to 'microphenominalism' (particle wisdom) it is interesting that the only two examples of probablistic behaviour of which we know are that of micro-phenomena and that of conscious beings. All other examples are a just a function of our lack of knowledge of the determining parameters.

    It might be objected that conscious behaviour is strictly physically determined, but at the moment that is a conjecture. It appears to be probablistic, hence the primacy of statistical data in sociology etc. rather than individual cases.

    Are there any other cases of probablistic behaviour? If not then it would seem that we have some strange and rare property in common with electrons.

    Then again this might be nonsense.
  11. Feb 28, 2004 #10


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    On this issue of "other conscious things" I have a problem with d'Espagnat. He says that as decoherence increases, accuracy of microconscious prediction gets better, and that's how microconsciousness becomes macroconsciousness. But by the time you have Avogadro's number of atoms or molecules - a tiny drop of water, say - you have matter that behaves classically. In other words, decoherence has maxed out. So is a drop of water macroconscious? Is a rock? According to d'Espagnat, it seems to me, they would be.
  12. Feb 29, 2004 #11
    I don't have the knowledge to entirely understand d'Espagnat's article, although as far as I do it seems to make a lot of sense. I didnt notice any implication that drops of water are conscious. I assumed that large collections of microscopic consciousness entities become a single 'classical' entity due to statistical probability, not shared consciousness. But I may well have misunderstood.

    I'm not clear exactly what he means by the term 'predictive consciousness'. If you are can you clarify it for me?
  13. Mar 1, 2004 #12
    Does d'Espagnat have a website. I can not get to any of the links or mirror sites posted on this thread. I would like to read this and comment on it. d'Espagnat's paper, it is quant-ph/0402121
    e-mail: matthew.donald@phy.cam.ac.uk
    address: Dr. Matthew J. Donald,
    The Cavendish Laboratory,
    Madingley Road,
    Cambridge, CB3 0HE,
    web site: http://www.poco.phy.cam.ac.uk/~mjd1014 [Broken]
    The physics e-print server does have a Spanish mirror which is at http://es.arXiv.org/
    abstract for d'Espagnat's paper at http://es.arXiv.org/abs/quant-ph/0402121
    These links work in Europe if anyone has the same problem.
    Last edited by a moderator: May 1, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook