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B Second Law and "Hidden Variables"

  1. Jul 28, 2015 #1
    Does QM uncertainty cause/explain the Second Law of Thermodynamics? If so is entropy the contribution of hidden variables, to our classical world? How about negentropy?

    http://arxiv.org/abs/quant-ph/0605031

    Irreversibility in Collapse-Free Quantum Dynamics and the Second Law of Thermodynamics
    M. B. Weissman
    (Submitted on 2 May 2006)
    Proposals to solve the problems of quantum measurement via non-linear CPT-violating modifications of quantum dynamics are argued to provide a possible fundamental explanation for the irreversibility of statistical mechanics as well. The argument is expressed in terms of collapse-free accounts. The reverse picture, in which statistical irreversibility generates quantum irreversibility, is argued to be less satisfactory because it leaves the Born probability rule unexplained.

    Comments: 13 pages
    Subjects:
     
  2. jcsd
  3. Jul 28, 2015 #2
    Negative entropy? Improbable if not impossible. That's like negative gravity. I don't think it's possible.

    I was just thinking about something along these lines a few days ago but haven't come to any definitive conclusions yet. I will have to read the paper later.
     
  4. Jul 28, 2015 #3
    Last edited by a moderator: May 7, 2017
  5. Jul 28, 2015 #4
    Is that supposed to be like "resistance" to entropy?
     
  6. Jul 28, 2015 #5

    Strilanc

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    Science Advisor

    It's intuitively convenient to imagine processes that increase entropy as instead consuming negative-entropy. For example, instead of seeing life as increasing entropy you can view it as consuming negentropy. The math is exactly identical, modulo some cancelled-out negative signs, and no new physical phenomenon is being postulated.
     
  7. Jul 28, 2015 #6
    It's useful in talking about emergent order in systems driven from equilibrium.

    They don't use the term "negentropy", but this paper discusses the phenomenon of emergent order (locally decreasing entropy) in systems driven out of equilibrium - and how it relates to dissipative efficiency, which is related, as I understand it (and per the wiki) to relative rate of entropy production (though I think that is controversial)


    http://arxiv.org/pdf/1412.1875v1.pdf
    Statistical Physics of Adaptation
    Nikolai Perunov, Robert Marsland, Jeremy England
    (Submitted on 5 Dec 2014)
    All living things exhibit adaptations that enable them to survive and reproduce in the natural environment that they inhabit. From a biological standpoint, it has long been understood that adaptation comes from natural selection, whereby maladapted individuals do not pass their traits effectively to future generations. However, we may also consider the phenomenon of adaptation from the standpoint of physics, and ask whether it is possible to delineate what the difference is in terms of physical properties between something that is well-adapted to its surrounding environment, and something that is not. In this work, we undertake to address this question from a theoretical standpoint. Building on past fundamental results in far-from-equilibrium statistical mechanics, we demonstrate a generalization of the Helmholtz free energy for the finite-time stochastic evolution of driven Newtonian matter. By analyzing this expression term by term, we are able to argue for a general tendency in driven many-particle systems towards self-organization into states formed through exceptionally reliable absorption and dissipation of work energy from the surrounding environment. Subsequently, we illustrate the mechanism of this general tendency towards physical adaptation by analyzing the process of random hopping in driven energy landscapes.
    Comments: 23 preprint pages, 4 figures
    Subjects: Biological Physics (physics.bio-ph); Statistical Mechanics (cond-mat.stat-mech); Populations and Evolution (q-bio.PE)
    Cite as: arXiv:1412.1875 [physics.bio-ph]
    (or arXiv:1412.1875v1 [physics.bio-ph] for this version)
    Submission history
    From: Jeremy England [view email]
    [v1] Fri, 5 Dec 2014 01:46:11 GMT (1594kb,D)
    Which authors of this paper are endorsers? | What is MathJax?)
     
    Last edited: Jul 28, 2015
  8. Jul 28, 2015 #7
    Thanks, I get that. Two wrongs do make a right.

    I haven't read either of these papers you referred to yet, or the book which sounds quite interesting as well, but I can say one thing... Our universe appears to be "order" emerged, and constantly assaulted, from and by entropy.
     
  9. Jul 28, 2015 #8
    I agree, I just can't help wondering about the details of it's apparent resistance.
     
  10. Jul 28, 2015 #9
    I suddenly am urged to think in terms more like the Carnot cycle. Not so much as a resistance, I'm thinking it might be more of a "utilization" of entropic energy, so to speak. In fear this may be seen as leaning towards a personal theory, I mean this simply as an interpretational analogy. Biology obviously overcomes environmental chaos by some truly phenomenal means.
     
  11. Jun 17, 2016 #10

    Mark Harder

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    Gold Member

    Yes, I don't like the term either. Entropy itself is always greater than zero. S = k lnW. W >1 so the ln is positive and monotonic increasing. If you're inclined to think in terms of information and its loss, then I suppose 'negentropy' could be equated with information, and entropy related to information loss. Is there any advantage whatever in using the other term? Does it add anything?
     
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