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Smolin's Edge Response - Deterministic Quantum Theory?

  1. Jan 18, 2013 #1
    Did anyone read Lee Smolin's response to the Edge.org question: "What are you worried about?"

    http://edge.org/response-detail/23778

    Opening paragraph:

     
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  3. Jan 18, 2013 #2

    marcus

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    As I recall he didn't say anything very definite about what such a theory might look like, so I didn't pay very close attention. It's not unusual for people to propose deterministic theories that they think might underlie and give rise to the quantum probabilistic behavior we observe.

    Last year I heard Gerard 't Hooft give two talks about his current pet idea for a deterministic quantum theory---one was a well-attended seminar with a high proportion of faculty and postdocs. So there is interest in this kind of thing. Personally it didn't grab me, but 't Hooft is congenial and impressive to watch.

    About 5 years ago, Smolin was proposing such a thing---I think it may have been based on what he called "disordered locality" but I could be confusing two research papers. I don't have an accurate memory of it. Anyway he too, at that time, had a definite proposal for a deterministic basis for quantum theory.

    There may be conferences which have been all or part devoted to this kind of thing. For some reason I don't find it at all interesting. Anyway I think Smolin and 't Hooft are just two examples out of many who've aired thoughts about it.
     
  4. Feb 2, 2013 #3
    As every one knows here, I like to play the role of "mister naive" and concerning that topic (a deterministic origin for the quantum theory), I have a old standing question. When I was a student (thirty years ago), teachers used to say that electrons are situated/moving "around" the nucleus of a given atom and that we may only find them at a given place with a given probability. That probability is normalized in such a way that, if we integrate it on the whole spacetime, we find 1. This is the more or less official quantum interpretation; the theory has introduced the probability of presence as an indirect consequence of the HUP. Well this is one side of the story. In between I have heard about the tunnel effect (also another consequence of the way of thinking developped by the quantum theory). So, now comes my questions: "Do we actually consider that a particle which is tunneling (in extenso: traveling in an energetically forbidded region - things being seen from the classical point of view) exists in the classical sense of that word?" If the answer is: no (= a tunneling particle does not exist in our classical world), could we not see here the starting point for an alternative and deterministic interpretation? In extenso, if have only 50 chances under 100 measurements to find an electron here and now, does not this fact only means that that electron is just tunneling the half of the time here (due to some topological modifications)? Despite of my not optimal english I hope my question is clear enougth. Do you have some scientific references going in that direction? Thanks
     
  5. Feb 3, 2013 #4
    No, I don't think so; but nevertheless it seems a 'real' phenomenon ....quantum stuff does 'exist' in our world.

    how about tunnel diodes, Josephson junction, a possible way the big bang started, Hawking black hole radiation, fission, fusion.......

    are my first thoughts.....


    ok, so as not to appear too idiotic, I checked...

    "quantum tunneling" turned up similar stuff..

    http://en.wikipedia.org/wiki/Quantum_tunneling

    See what you think....

    also,bunch of references given at the end of the article.
     
  6. Feb 3, 2013 #5
    Did anyone read Lee Smolin's response..........

    I have seen that quote.....and I have a book of Smolin's that treks along those lines:

    Smolin
    THREE ROADS TO QUANTUM GRAVITY, 2001, a book for the general public...

    It's a story of how different theories relate to at an as yet incomplete quest for a theory of quantum gravity ..things like GR, QM, LQG, holographic insights, string theory,etc.....I found it a good introduction to some of the things we think we know and some we know we don't know.
     
  7. Feb 3, 2013 #6
    I am happy to read the Smolin words. When we start out as young students, the quantum is very mystify. Then we learn what the maths are and there is a bifurcation. Some will say, "Now I understand." Others will say, "I still do not understand." To me quantum theories are engineers solution to philosopher's problem. So the students who get diploma and say "Now I understand," those are the engineers. The physicist agree with Smolin and do not understand.

    "If you are hammer, all problems look like nails." ...so it is with people who "understand" quantum theories.
     
  8. Mar 8, 2013 #7
    John Archibald Wheeler: Law Without Law, 1983
    http://what-buddha-said.net/library/pdfs/wheeler_law_without_law.pdf

    “Is thre not some underground machinery beneath the working of the world which one can ferret out to secure an advance indication of the outcome? Some secret determiner, some “hidden variable”? Every attempt, theoretical or observational, to defend such a hypothesis has been struck down. Not the slightest hard evidence has ever been found that would throw doupt on the plain, straightforward prediction of quantum mechanics, the prediction that no prediction is possible. Probability? Yes. A definite forecast? No. Einstein could be unhappy that “God plays dice”; but Bohr could tell him jokingly, “Einstein, stop telling God what to do.”
     
  9. Mar 9, 2013 #8
    Carlo Rovelli has this to say about quantum phenomena in UNFINISHED REVOLUTION [a research paper]

    And Roger Penrose has made these observations:


    The following quote is from Roger Penrose celebrating Stephen Hawking’s 60th birthday in 1993 at Cambridge England.....this description offered me a new insight into quantum/classical relationships:

     
  10. Mar 9, 2013 #9
    must come some day....
     
  11. Mar 9, 2013 #10

    marcus

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    ==quote from edge.org, Lee Smolin==
    Still, I don't believe quantum mechanics gives a complete description of nature. I strongly believe there is another, truer description, waiting to be discovered.
    ==endquote==

    Now he has made a fairly detailed presentation of a proposal of a deeper theory underlying QM. They are doing computer simulations to see if it can generate realistic probabilities in simple situations.

    Smolin's new book Time Reborn gives a lengthier description. It comes out in a month or so from now.

    But this Perimeter Institute video gives a brief desription and explain the reasoning and motivation behind it. The video is quite recent: 26 February 2013. Just eleven days ago.

    to get it, google "smolin pirsa"
    or click on this:
    http://pirsa.org/13020146/

    The title of the video lecturer is The universe as a process of unique events.

    He has discovered an elegant minimalist way in which regularities (physical laws) can EVOLVE, so there are no fixed eternal physical laws above or outside the universe. The laws are an evolving part of the universe like everything else. The model also generates probabilities. It is extremely simple. the question is, could it generate the same probabilities as quantum mechanics, and thus fit observation?
     
    Last edited: Mar 9, 2013
  12. Mar 9, 2013 #11

    marcus

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    Back in January when Inflector started this thread, I posted a very unenthused response. Now after watching Smolin's February Pirsa video, which is a very interesting talk, I have changed my mind.

    Before I did not read the Edge 2013 Question response perceptively and I was thinking of earlier ideas of Smolin's along these lines that, it seemed to me, had not gone anywhere.
    And the book with Roberto Unger that never seemed to get pubished. But now that has changed.

    1. a coherent picture of the universe, containing evolving regularities (natural laws) has come to fruition, and it even seems to be testable. It's presented in the 26 February video lecture.

    2. the book with Roberto Unger is finished and is being read by potential publishers (but not yet in press)

    3. Smolin has his own book, Time Reborn, containing a simplified wide audience account of these ideas, that is actually being reviewed. It goes on sale in April.

    So the situation has moved forward and I want to sit up and take notice.

    the idea could be right or wrong, we don't know, but in any case it is interesting. It is also radically ANTI-MULTIVERSE. Nothing above or outside. Nothing causing stuff that is not itself reacted back on. Nothing happening without a sufficient reason. No purely random stuff (but still effective probabilistic stuff, quantum mechanical uncertainty can emerge, something I don't understand yet.) Physical law is subject to explanation like everything else. There is a kind of uncompromising pragmatic empirical spirit about the proposed world-system.

    It's a clever scheme that puts all these things together.

    Rob Myers is in the audience and IIRC he asks one or more respectful questions to which Smolin answers at length. Neil Turok the director at Perimeter is also in the audience, I don't recall whether he asks a question or makes a comment. The video may bear watching again. After re-reading and thinking about the Edge 2013 response that Inflector linked in post #1.
    http://edge.org/response-detail/23778
    http://pirsa.org/13020146/ (26 February video lecture)
    https://www.amazon.com/Time-Reborn-Crisis-Physics-Universe/dp/0547511728
     
    Last edited by a moderator: May 6, 2017
  13. Mar 10, 2013 #12
    Yes, I did and I did also read the recommanded link concerning the tuneling.

    In one of the last paragraphs Smolin suggests that (citation) ... : "a complete theory of quantum phenomena must contain a theory of space and time..." (end of the citation).

    So my stupid question: "How are actually the "psy" functions (representing the waves) related to positions and time?" Are they depending on position and time such that we arbitrarily have Psy = Psy(x, t)? Or are these Psy(x, t) the diverse representations in the quantum world of the speeds of the particles? Why do I ask so? In fact just because a non linear projection of the Lorentz-Einstein law of motion can be mathematically represented by a law which is very similar to the Schrödinger equation (You can check it if you want)!

    What is the official situation today concerning the incorporation of spacetime into a quantum theory?
     
  14. Mar 10, 2013 #13

    marcus

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    "official":biggrin:

    Probably the "incorporation of space-time into a quantum theory" is an ongoing creative process about which it is impossible to have an official report. In post #3, you mentioned the "role" of asking Mr. Naive questions. I really appreciate when people take on this role. Thanks.

    My private assessment of the situation today is that the Plebanski action for geometry is very important because it does not need background geometry and it can be extended to include matter fields. So I think that one should listen to the two online talks by Alexander (26 Feb) and by Marciano (May). They are the highest risk talks of the season---about incorporating both matter and geometry in the same backgroundless action. There is also the December 2012 paper by Alexander Marciano Smolin.

    It is known how to quantize the Plebanski action (and extensions of it) via triangulation.
     
  15. Mar 10, 2013 #14

    marcus

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  16. Mar 24, 2013 #15
  17. Mar 24, 2013 #16
    Don't misunderstand this "official". I just meant "the academic position", what is teached in universities... Nothing else. Otherwise, I want to tell you that the physicsforums are no more secure, safe and that for example, my account has been hacked.

    That's the reason you wull never more heard from me.
     
  18. Mar 27, 2013 #17

    Fra

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    A while since I was here.

    I have been waiting for that book. Judging from how I perceived Smolins ideas to be scattered and drifting I was almost convinced he had lost the track (to my dissapointment)

    If I can get my hands on that book i will definitely read it. My highest hopes are on Unger to guide Smolins sometimes incoherent but more technical ideas (as I perceived it) in a fruitful direction.

    Yes indeed, but so far the sense I get from Smolins response in the edge post does not look (from my information abstracted perspective) too promising. But I REALLY look forward to the book!

    Do you have any info on it? isbn number? where can we get it eventually?

    /Fredrik
     
  19. Mar 27, 2013 #18

    marcus

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    for goodness sake, Fra, google "pirsa smolin" and watch his video TALK about this.
    It is far more specific, and interesting, than the Edge response.

    The Edge response is just a vague teaser for what he is talking about with actual diagrams and stuff in his video talk.

    The book is on Amazon (for pre-order). you merely google the book title "Time Reborn"
    together with what information you think appropriate, like
    "amazon smolin time reborn"

    I don't KNOW that the book will be as specifically interesting to you as the pirsa video talk.
    the talk is for fellow scientists and focused on the new ideas, it is not for popular wide audience.

    If you have any trouble getting the video talk, please let me know and I'll help.

    Haven't seen you for quite a while! Hope you are well and keeping busy :-D

    Oh, here is the PIRSA link:
    http://pirsa.org/13020146/
    "The universe as a process of unique events"
     
  20. Mar 27, 2013 #19

    Fra

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    Thanks Marcus for the direct pointer! I'll check that out!

    Yes I'm doing well just too much to do to be omnipresent unfortunately. I hope you're well too!

    /Fredrik
     
  21. Apr 12, 2013 #20
    Very interesting and promising direction. As an outsider coming to physics as an accomplished adult about six years ago, I found the baseline assumption of many physicists that quantum reality is fundamental and therefore that causality is an emergent phenomenon to be misguided, at best. After all, how does causality emerge from an acausal substrate? Sort of like building with sand and no binder to hold the sand together.

    It also strikes me that deBroglie-Bohm demonstrated that this was not necessary, so I have always been puzzled at the mass adoption of the quantum-reality-is-fundamental perspective.

    So going back to causality as fundamental is, at the very least, a better philosophical foundation.
     
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