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

Metaphysics and QM

  1. Feb 3, 2010 #1
    Hi all

    I have some questions regarding interpretations of QM. I am not a physicist or mathematician, although I have good general knowledge of science. I'm a philosopher with an interest in the relationships between science, religion and metaphysics.

    I am trying to link together many different problems and clues, and I need to narrow down my own views on QM interpretations, which isn't easy given the vast number of conflicting authorities on the subject. I have plenty of views about metaphysics. My problem is figuring out which existing interpretation of QM is closest to my own view. I must stress that I have come to the my own position on metaphysics for reasons which have little or nothing to do with QM. QM is just one of the remaining bits of the puzzle for me. I know sort-of where it goes in my scheme, but that's not good enough.

    Ontologically, my position is closest to neutral monism, and I also believe there are some sort of hidden variables at work in reality - some hidden form of causality, possibly manifesting via quantum indeterminism. So I guess I'm on the same page as Bohm-de Broglie. I also strongly suspect that there is a link between quantum mechanical properties in the brain and consciousness. Why do I think this? Because I do not believe we have any other way of solving the mind-body problem. However - I am in no way commited to any of the existing "consciousness causes collapse" theories, and certainly not any specific suggestions e.g. Penrose/Hameroff. I think they had the right basic idea, but even Paul Davies rejects Hameroff and I simply don't understand Penrose's mathematics well enough to judge his theory.

    Steven Wolfram believes science is heading for a revolution - that we will eventually come to understand that reality is little more than an iterating mathematical structure. I think he's right. If you think of reality as being made of information, then the mind-body problem is half way to being dissolved. I don't think there was any "matter" before consciousness evolved. There was just information, some of which corresponded to what we call the material world.

    So the world (as it is in itself) is "made of" information. This information structure hangs off the present moment - now. Some information about previous and future iterations is also part of this structure, but the further into the future or past you go, the less "fixed" or defined it becomes. So the near past and near future are almost completely fixed, but only vaguest traces remain of the deep past and only vaguest "visions" of the distant future are yet to be created. Classical causality just operates in a forward temporal direction, working iteration by iteration. Quantum causality operates in both directions, and influences the information held about more temporally-distant iterations. It can re-fix bits of the past which have decayed, so in this sense it may be possible for "the past to change". It obviously also means the future is not fixed.

    What does this have to do with consciousness? I think that early animal life forms were restricted to classical causality, and that as a result they were not conscious. At some point, some quantum property of the brain evolved (by random mutation) which allowed them to take advantage of quantum causality. This enabled them to be conscious, which gave them a massive advantage over the zombie-animals that went before them and could only react on an iteration-by-iteration basis.

    My questions are these:

    Whose version(s) of quantum mechanics should I be investigating?

    Is anything I've said so far contradictory of the core scientific components of QM.

    I am not interested in challenging the scientific theory of QM. What concerns me is the metaphysical interpration of that theory, because I need to tailor the rest of my own metaphysical position to make it consistent with at least one scientifically-acceptable metaphysical interpretation of QM. In other words, I'm not bothered about any metaphysical objections people might have to my wider view but I am very concerned about being accused of overstepping the boundaries of metaphysics (philosophy) and making scientifically-unacceptable statements.

    Last edited: Feb 3, 2010
  2. jcsd
  3. Feb 3, 2010 #2
    Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Apr;61 4 Pt B 4194-206.

    Importance of quantum decoherence in brain processes.

    Tegmark M.

    Institute for Advanced Study, Olden Lane, Princeton, New Jersey 08540, USA.

    Based on a calculation of neural decoherence rates, we argue that the degrees of freedom of the human brain that relate to cognitive processes should be thought of as a classical rather than quantum system, i.e., that there is nothing fundamentally wrong with the current classical approach to neural network simulations. We find that the decoherence time scales ( approximately 10(-13)-10(-20) s) are typically much shorter than the relevant dynamical time scales ( approximately 10(-3)-10(-1) s), both for regular neuron firing and for kinklike polarization excitations in microtubules. This conclusion disagrees with suggestions by Penrose and others that the brain acts as a quantum computer, and that quantum coherence is related to consciousness in a fundamental way
  4. Feb 3, 2010 #3
    Hi YJ

    Can you give me some idea how such a calculation is done?

    It is based on empirical measurement of average neural decoherence rates? Presumably not, since it was calculated. If so, what are the key factors fed into the calculation?

  5. Feb 3, 2010 #4


    User Avatar
    Gold Member

    Hi Erwins mat

    I spent about 10 years in consciousness studies. I think you are making the usual big mistake in trying to tie QM (a model of the ultimately simple) to consciousness (a model of a process defined by its extreme complexity).

    But to be helpful to your purposes, I have collected this thread relating to the notion of vagueness.


    And you might want to check Prigogine's book on time and entropy (The End of Certainty) and Cramer's transactional interpretation of QM, if you haven't already.

    Neither a vagueness-based causality nor transactional QM would operate the way you suggest though.

    Vagueness allows for a weaker form of classical global future determination (and so a greater scope for local freedom - creativity or randomness in "mechanistic" processes). That is the kind of thing Prigogine was talking about.

    Transactional QM (in my view) is pointing towards the idea that time on the local scale (such as the path connecting any two points of spacetime) is "going both ways", or is otherwise symmetric. In effect, the two ends of an interaction have to come to some agreement about how an event between them occurs. Which includes taken into account all the factors along the path, such as experimenters doing twin slit measurements.

    Then globally, due to the additive nature of all these local across-time strands of action, we get the asymmetric global arrow of time which we are more familiar with as classical time. The global case is thus the limiting distribution that emerges.

    In this view, the past does not decay and need re-fixing. It just gets left behind as "paths now definitely not taken".

    Putting the two together, we could say there was an hot electron in a far distant star a billion years ago. Its state was vague - quantum indeterminate. Then an interaction was negotiated over spacetime in which my eyeball became the photon absorber. Crisply, an event was created. A photon was definitely emitted (and at the same moment a billion years ago, the many other vaguely potential destinies of that photon were ruled out with equal crispness).

    You can see how that event becomes something definite woven into a growing history of many other definite events, and so globally, time ratchets on. The second law of thermodynamics, and thus irreversible arrow of time, emerges as the limiting distribution.

    So yes, there are schools of thought around the notion of vagueness. And the transactional interpretation is the one that seems closest to the acceptance that events on the local scale are symmetric (happening both ways) in spacetime. Or that they are non-local temporally.

    But this does not seem to me to support the idea that the past is changeable. Nor that we need hidden variables (as transactional thinking accepts the reality of non-locality - at the local "between spatiotemporal locales" level).

    Finally, consciousness is completely unneccessary for bringing reality into being.

    Tegmark's thermal noise paper cited by yoda jedi is a good rule of thumb argument against QM processes being relevant.

    Hameroff has tried to take the epicycle approach (adding ever more baroque detail) to evade Tegmark's strictures. But at least he retains the theoretical possibility of a causal chain of process stretching from QM to classical.

    If you don't even have a concrete proposal for a QM mechanism that can vault the thermal noise issue, then you have even less reason to suggest in hand wavey fashion that QM could somehow be basic.

    This is the kind of hand wavey bit that gets knocked down straight away. Again, Hameroff's speculations may be biologically preposterous, but at least there is a concrete proposal on the table.

    You do have other biologically plausible ways of modelling consciousness based on neuroscience and complexity theory - dissipative structure theory, generative neural nets and complex adaptive systems being three schools of thought which come closest in my opinion.

    Even metaphysics would need to deal with concrete proposals on the table, dismissing them for some better reason than Chalmer's hard problem rhetoric, before it steps back to "vaguer" thoughts based on unknown and unspecified causal linkages between QM and consciousness.
  6. Feb 3, 2010 #5

    Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Apr;61 4 Pt B 4194-206.

    Importance of quantum decoherence in brain processes.

    Tegmark M.

    ............(∼ 10−3 − 10−1 seconds)......for regular neuron firing.......
    ...............This chain reaction, “firing”, propagates down the axon at a speed of up to 100 m/s, changing the potential difference to a value U1 that is typically of order +0.03V [49].
    The axon quickly recovers. After less than ∼ 1ms, the sodium channels close regardless of the voltage, and large potassium channels (also voltage gated, but with a time delay) open up allowing K+ ions to flow out and restore the resting potential U0. The ATP driven pumps quickly restore the Na+ and K+ concentrations to their initial values, making the neuron ready to fire again if triggered.Fast neurons can fire over 103 times per second.................

    [49].J. P. Schad´e and D. H. Ford, Basic Neurology.


    .........The problem is that the matter inside our skulls is warm and ever-changing on an atomic scale, an environment that dooms any nascent quantum computation before it can affect our thought patterns. For quantum effects to become important, the brain would have to be a tiny fraction of a degree above absolute zero...........

    ...........Some members of the quantum-consciousness community, however, concede that Tegmark has landed a body blow on Penrose-Hameroff-type views of the brain. "Those models are severely impacted by these results," says physicist Henry Stapp of Lawrence Berkeley National Laboratory in California..................

    .............Physicists outside the fray, such as IBM's John Smolin, say the calculations confirm what they had suspected all along. "We're not working with a brain that's near absolute zero. It's reasonably unlikely that the brain evolved quantum behavior," he says. Smolin adds: "I'm conscientiously staying away" from the debate...................
    Last edited: Feb 3, 2010
  7. Feb 3, 2010 #6
    Hello apeiron


    What does the word "consciousness" mean to you, and how do you think it acquired its meaning?

    I have to understand the thermal noise issue first...

    I know it is hand-wavey. I am not basing any scientific claims on it. I was merely explaining where I am coming from metaphysically. I am not a quantum physicist. I'm interested in WORDS - how they get their meanings and how they are used in certain contexts. When it comes to science, my area of expertise is ecology, biology, evolution and genetics. I want to know how, when and why the capacity for animals to be conscious evolved.

    Metaphysics must always be informed by the best science can offer.
  8. Feb 3, 2010 #7


    User Avatar
    Gold Member

    Another great book for you perhaps then is Kurt Danzinger: Naming the Mind: How Psychology Found its Language. Thousand Oaks, CA: Sage Publications, 1997. That traces the development of mind terms very nicely.

    What do I mean by "consciousness"? That is a very good question.

    It has a general folkloric use that is quite fallacious imho. It conflates introspective self-awareness (a language-scaffolded skill) with "raw awareness". And then raw awareness is actually something else as well - more to do with extrospection and anticipation.

    So I am much happier deconstructing the term into better theory and evidence backed jargon.

    I am comfortable, for example, with talking about attentive processing or forward modelling - things that are to do with the folk psychology notion of being an aware human (as distinct from a minimally aware plant and non-aware rock), but also rooted in stuff you can point a finger at, like generative neural network models or the known functions of the anterior cingulate.
  9. Feb 4, 2010 #8
    Thankyou for your help.

    I do not believe that quantum effects in the brain have been ruled out. The reason I take this stance is the number of conflicting authorities (Penrose being far from the only person to have suggested it) and the fact that this is an ideologically-charged subject (i.e. there are metaphysical/religious/ideological reasons why certain sorts of people might be a little too eager to dismiss it). I have ordered a couple of books by Henry Stapp. They should keep me busy for a couple of weeks...

    As for consciousness...self-awareness isn't a "skill". It isn't a behaviour, it is a process, it isn't anything "material" and the sooner scientists stop kidding themselves that it is, the sooner they will stop talking nonsense. This is not the place for it (I came here for information about QM) but I think that the problem of consciousness needs to be sorted out - or at least faced up to - before people start dismissing any possible links with QM.
  10. Feb 4, 2010 #9


    User Avatar
    Gold Member

    Self-awareness is certainly a skill. There is plenty of science to support this. Read Lev Vygotsky.

    But I agree there is a deep philosophical issue for science in tackling conscious experience itself. Materialistic approaches are unsatisfactory as they do not really give you an account of the formal aspects of the phenomenon.

    You might say material explanations are designed to deal with quantity and you also need a naturalistic account in terms of form or organisation to deal with the qualitative aspects.

    So something really is missing from the majority of scientific approaches to mind. The question then is how to model the formal aspects of mind - which is where complex adaptive systems, the maths of hierarchy theory, etc, come in.

    But QM can be safely dismissed.

    For a start, it too is a bottom-up material/quantitative approach to modelling. It is part of the same problem. The lack of a formal or qualitative aspect to QM is why we have the observer issue. There is no model of the global context which "collapses the wavefunction".

    The problem I believe is that people who are attracted to "mystery" get attracted to both QM and consciousness as things they want to say something about. And it is even more fun for these people if the two can be put together in the same frame. Throw in psi and other spookiness and endless speculation is possible.

    So the motivation is sociological rather than evidential.

    The link between QM and consciousness is not being dismissed. The point is that one has yet to be found.
  11. Feb 5, 2010 #10
    Oh, really? So a completely-paralysed patient (let's say one who is on an operating theatre and the anaesthetist has bodged the job) is completely self-aware, but totally unable to move. That's a skill? Only if you want to abuse language in order to defend scientific nonsense.

    That's one problem - the scientific side of it. I would really call this more like "brain simulation", but that's a just a name.

    My Henry Stapp book arrived five minutes ago.. He sez yur wrong! :D

    Really...from a non-quantum-physicist's point of view, there is nothing but a whole load of conflicting authorities. Event the "quantum revolutionaries" don't agree with each other, and neither do the defenders-of-the-old-paradigm who are trying to dismiss the revolutionaries.

    It's a mess.

    This much I understand. The "observer" is undefined.

    And I find that specific response highly irritating. That is an attempt at a psychological explanation. It's like Richard Dawkins saying people believe in God because they need an imaginary friend. It's (a) deeply insulting, (b) absurd (do you really think Roger Penrose is "attracted to mystery? and (c) fails to take account of the real reasons why people bring the two problems together.

    They are both metaphysical problems involving the apparent failure of (naive) materialism and the apparent absence of an "observer". In other words, they are both non-scientific problems of a related metaphysical nature. It is therefore entirely reasonable to ask whether they may in fact be two aspects of a single problem. MANY people have tried pointing this out in one way or another. "You need an imaginary friend" is NOT an appropriate response.

    On the contrary, I believe that your motivation is ideological ("anti-woo") rather than rational. Neither problem has anything to do with empirical evidence.

    Well, hopefully I just answered that. There is no scientific link. There is a good reason for this: neither problem is a scientific problem. Is there are metapysical link? You bet there is.
  12. Feb 5, 2010 #11
    I have just spent a couple of hours reading through Henry Stapp's "Mindful Universe". This is the book I was looking for. What are your objections to Stapp's position?
  13. Feb 5, 2010 #12


    User Avatar
    Gold Member

    How would paralysis in your example affect a learnt mental skill based on the internal use of language? I don't feel you really understand the point.

    It is your choice. You can study the sociology, psychology and neurology of human consciousness, then argue how the science falls short. Or you can jump in and speculate in typical amateur fashion.

    But you have already decided QM is your solution, so sorry, I know I am wasting my breath.
  14. Feb 5, 2010 #13
    of course, no yet.
    no exhaustively.


    time will tell............

    i agree.
    dismissing or linking it.
  15. Feb 6, 2010 #14
    If you want to defend materialism, you're wasting your breath. It died 75-100 years ago, we're just still waiting for the greiving relatives to organise the funeral.

    Henry Stapp would appear to agree with me. Is this an argument from authority? Yes an no. Yes, because I'm a philosopher, not a quantum physicist. I depend on authorities when outside my own field.

    Or is Stapp a woo-woo?
  16. Feb 6, 2010 #15
  17. Feb 6, 2010 #16


    User Avatar
    Gold Member

  18. Feb 6, 2010 #17
    How do you decide what/who is woo-woo and what/who isn't?
  19. Feb 6, 2010 #18


    User Avatar
    Gold Member

    With Stapp et al, for example, they cite Pashler on attentive mechanisms and jump to QM without first properly dismissing the boring old classical/mechanical/material explanations for phenomena like "attention subtracts from muscular effort".

    And the boring explanation is that max skill is the result of minimum attentional need. Standard attention vs habit psychology.

    You can do boring stuff like measure the electrical activity of the muscles of skilled vs beginners in any complex skill, like swinging a tennis racket, and you will find beginners are pulling on muscles all over the place while the skilled have almost silent action. We all know that muscles are designed so that as one tightens, others must relax. And a stiff arm is a slow and weak arm.

    So there you go. Stuff that everyone who does sports psychology or psychophysics will know.

    And Stapp et al are going "woo woo" its a mystery to classical science. When it just isn't.

    It is like you when started off with your paralysed patient story to "prove" self awareness and introspection can't be learnt, language-scaffolded, skills.

    Now there is a big literature on paralysis, let alone the thought and language argument. You can't just throw things into a discussion off the top of your head and then ignore the groaning library shelves of solid research.
  20. Feb 7, 2010 #19
    There is a fundamental reason why you do not understand the motives or line of reasoning of "Stapp et al". You are demanding/expecting scientific justification for the link between QM and consciousness before you are willing to consider their ideas. but their reasons for linking QM and consciousness (and mine) aren't scientific at all. They are metaphysical.

    I believe you have fundamentally misidentified the boundary between physics and metaphysics.
  21. Feb 7, 2010 #20


    User Avatar
    Gold Member

    What purpose do they serve by emulating science then?
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook