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Axiom of QM is Observation.. but

  1. Jan 29, 2016 #1
    It is said the axiom of QM is observation.. but if observation is secondary effect of more primary dynamics that don't involve observations.. could it still be called QM, and what's it supposed to be called? In other words. Say QM is emergent from a deeper reality.. and we are to study the deeper reality.. how should you call that subject and what would its axiom be?
     
  2. jcsd
  3. Jan 29, 2016 #2

    atyy

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    Science Advisor

    The problem is called the measurement problem.

    For non-relativistic quantum mechanics, one possible deeper reality is Bohmian Mechanics.

    There are other possibilities being investigated such as Many-Worlds, the Transactional Interpretation etc, but they are less developed at the moment.
     
  4. Jan 29, 2016 #3
    Is it possible for the deeper reality to be based on different axioms that doesn't involve observations? Meaning supposed QM and Observations were emergent?
     
  5. Jan 29, 2016 #4

    atyy

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    Maybe.

    http://arxiv.org/abs/quant-ph/0506115
    Generalizations of Quantum Mechanics
    Philip Pearle, Antony Valentini
    (Submitted on 14 Jun 2005 (v1), last revised 14 Oct 2005 (this version, v2))
    We review realistic models that reproduce quantum theory in some limit and yield potentially new physics outside that limit. In particular, we consider deterministic hidden-variables theories (such as the pilot-wave model) and their extension to 'quantum nonequilibrium', and we consider the continuous spontaneous localization model of wave function collapse. Other models are briefly discussed.
     
  6. Jan 29, 2016 #5
    Should that theoretical branch of physics outside the limit be called Subquantum Mechanics.. or Superquantum Mechanics.. what's the appropriate term?
     
  7. Jan 29, 2016 #6

    bhobba

    Staff: Mentor

    Different interpretations, different takes. They all lead to the standard formalism (ie the two axioms in Ballentine) but some have observations as foundational (eg ensemble), others don't (eg consistent histories, modern MW, BM and Quantum Darwinism ).

    Thanks
    Bill
     
  8. Jan 29, 2016 #7
    In very simple words, what are the two axioms of Ballentine?

    Ensemble as you described has observations as foundational.. how about in those others (eg consistent histories, modern MW, BM and Quantum Darwinism )... what do they say about observations?
     
  9. Jan 30, 2016 #8

    bhobba

    Staff: Mentor

    It cant be explained simply. See post 137:
    https://www.physicsforums.com/threads/the-born-rule-in-many-worlds.763139/page-7

    BM - observations are derived from the reality of particles and the pilot wave.

    Consistent Histories:
    https://www.math.rutgers.edu/~oldstein/papers/qts/node2.html [Broken]
    'DH may be regarded as a minimalist approach to the conversion of the quantum measurement formalism to a theory governing sequences of objective events, including, but not limited to, those that we regard as directly associated with measurements. Where the Copenhagen interpretation talks about finding (and thereby typically disturbing) such and such observables with such and such values at such and such times, the decoherent histories approach speaks of such and such observables having such and such values at such and such times.'

    Modern MW is decoherent histories where each history is a world.

    Quantum Darwinism has observations emerging from quantum states:
    http://arxiv.org/abs/0903.5082

    Thanks
    Bill
     
    Last edited by a moderator: May 7, 2017
  10. Jan 30, 2016 #9
    I've been reading a bit about Quantum Darwinism.. Is Zurek quantum imprints propagating in the environments supposed to have ontologically reality like Many world state vectors.. or they are supposed to be some kind of information flow.. what kind of substance are these information flow made of?
     
    Last edited by a moderator: May 7, 2017
  11. Jan 30, 2016 #10

    bhobba

    Staff: Mentor

    I think either fits. Although personally in that interpretation I would take it as real.

    Thanks
    Bill
     
  12. Jan 30, 2016 #11
    But what kind of substance are these information flow made of?
     
  13. Jan 30, 2016 #12

    bhobba

    Staff: Mentor

    Obviously nothing. Its a physical theory, things in the theory do not have to be made of anything - just connect with things that do.

    Thanks
    Bill
     
  14. Jan 30, 2016 #13
    In Copenhagen, the information flow (or state vectors) is made up of bits inside memory chips or ruler plots or abacus as they are just operations.
    In BM, the information flow (or state vectors) is made up of pilot waves.
    In Many Worlds, the information flow (or state vectors) is the object themselves
    In Ensemble.. the information flow (or state vectors) is not thought of or just ignored (ignorance interpretation which you followed)

    In the above context.. Which of the above is Quantum Darwinism closer to? Or can it be used in all interpretations? I thought Quantum Darwinism is another interpretation.
     
  15. Jan 30, 2016 #14

    bhobba

    Staff: Mentor

    That's not what state vectors are in Copenhagen - its a subjective state of knowledge similar to Bayesian probabilities.

    Thanks
    Bill
     
  16. Jan 31, 2016 #15
    In Bohmian, improper mixture becomes proper mixture because of the trajectory and position preferred.
    In Many words, improper mixture becomes proper mixture because each mixed state is a branch.
    In Ensemble. You don't want to think how exactly the improper becomes proper.. it's just justified since there is no way to know even in principle.. so we must just think it's proper mixture.. this is just changing the terms "shut up and calculate" to "im just ignorant of it".. this mode of thinking may be justified if we don't have a problem of unification of QM (QFT) and GR. In Einstein Relativity.. there is a relativity of observations. Can't we apply this to QM too? Remember Zurek wants to have all observations see the same thing.. perhaps there is a problem in the unification wherein you need to know how improper mixture becomes proper to solve it? How do you categorically discount this possibility.. and what do you think would it be if there is such a need to know basis?
     
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