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rodsika

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For those of us trapped in a corner with difficult choices of whether to believe many worlds are splitted off billions of times every second or whether there is Godlike power to collapse the wave function in the universe or whether waves can travel forward or backward in time (Transactional) or wave function that is instantaneous from end to end of the entire universe (Bohmian), etc. Neumaire Thermal Interpretation of Quantum Mechanics may offer us peace of mind and contentment that the mystery of quantum mechanics is solved. But the question is, is Neumaire Thermal Interpretation valid or tally with all experimental facts? If you have detected any conflict with experiments that can falsify his model, pls share it. If it's valid, maybe someone can put it at wikipedia. Neumaire can you pls create a more layman friendly introduction to it like describing in detail how it explains buckyball made up of 430 atoms that can still interfere with itself? I can't understand the vague abd incomplete explanation you put forth in your paper. Thanks.

Arnold Neumaire said:

"

I have my own interpretation.

I call it the the thermal interpretation since it agrees with how one does measurements in thermodynamics (the macroscopic part of QM (derived via statistical mechanics), and therefore explains naturally the classical properties of our quantum world. It is outlined in my slides at http://arnold-neumaier.at/ms/optslides.pdf and the entry ''Foundations independent of measurements'' of Chapter A4 of my theoretical physics FAQ at http://arnold-neumaier.at/physfaq/physics-faq.html#found0 . It is described in detail in Chapter 7 of my book ''Classical and Quantum Mechanics via Lie algebras'' at http://lanl.arxiv.org/abs/0810.1019 . See also the following PF posts:

https://www.physicsforums.com/showthread.php?p=3187039&highlight=thermal#post3187039

https://www.physicsforums.com/showthread.php?p=3193747&highlight=thermal#post3193747

The thermal interpretation

It is superior to any I found in the literature, since it

-- acknowledges that there is only one world,

-- is observer-independent and hence free from subjective elements,

-- satisfies the principles of locality and Poincare invariance, as defined in relativistic quantum field theory,

-- is by design compatible with the classical ontology of ordinary thermodynamics

-- has no split between classical and quantum mechanics,

-- applies both to single quantum objects (like a quantum dot, the sun or the universe) and to statistical ensembles,

-- allows to derive Born's rule in the limit of a perfect von-Neumann measurement (the only case where Born's rule has empirical content),

-- has no collapse (except approximately in non-isolated subsystems).

-- uses no concepts beyond what is taught in every quantum mechanics course,

No other interpretation combines these merits.

The thermal interpretation leads to a gain in clarity of thought, which results in saving a lot of time otherwise spent in the contemplation of meaningless or irrelevant aspects arising in poor interpretations.

The thermal interpretation is based on the observation that quantum mechanics does much more than predict probabilities for the possible results of experiments done by Alice and Bob. In particular, it quantitatively predicts the whole of classical thermodynamics.

For example, it is used to predict the color of molecules, their response to external electromagnetic fields, the behavior of material made of these molecules under changes of pressure or temperature, the production of energy from nuclear reactions, the behavior of transistors in the chips on which your computer runs, and a lot more.

The thermal interpretation therefore takes as its ontological basis the states occurring in the statistical mechanics for describing thermodynamics (Gibbs states) rather than the pure states figuring in a quantum mechanics built on top of the concept of a wave function. This has the advantage that the complete state of a system completely and deterministically determines the complete state of every subsystem - a basic requirement that a sound, observer-independent interpretation of quantum mechanics should satisfy.

The axioms for the formal core of quantum mechanics are those specified in the entry ''Postulates for the formal core of quantum mechanics'' of Chapter A4 of my theoretical physics FAQ at http://arnold-neumaier.at/physfaq/physics-faq.html#postulates . There only the minimal statistical interpretation agreed by everyone is discussed. The thermal interpretation goes far beyond that, assigning states and an interpretation for them to individual quantum systems, in a way that large quantum systems are naturally described by essentially classical observables (without the need to invoke decoherence or collapse). The new approach is consistent with assigning a well-defined (though largely unknown) state to the whole universe, whose properties account for everythng observable within this universe.

The fundamental mathematical description of reality is taken to be standard quantum field theory. It doesn't matter for the thermal interpretation whether or not there is a deeper underlying deterministic level.

In my thermal interpretation of quantum physics, the directly observable (and hence obviously ''real'') features of a macroscopic system are the expectation values of the most important fields Phi(x,t) at position x and time t, as they are described by statistical thermodynamics. If it were not so, thermodynamics would not provide the good macroscopic description it does.

However, the expectation values have only a limited accuracy; as discovered by Heisenberg, quantum mechanics predicts its own uncertainty. This means that <Phi(x)> is objectively real only to an accuracy of order 1/sqrt(V) where V is the volume occupied by the mesoscopic cell containing x, assumed to be homogeneous and in local equilibrium. This is the standard assumption for deriving from first principles hydrodynamical equations and the like. It means that the interpretation of a field gets more fuzzy as one decreases the size of the coarse graining - until at some point the local equilibrium hypothesis is no longer valid.

This defines the surface ontology of the thermal interpretation. There is also a deeper ontology concerning the reality of inferred entities - the thermal interpretation declares as real but not directly observable any expectation <A(x,t)> of operators with a space-time dependence that satisfy Poincare invariance and causal commutation relations.

These are distributions that produce measurable numbers when integrated over sufficiently smooth localized test functions.

Deterministic chaos is an emergent feature of the thermal interpretation of quantum mechanics, obtained in a suitable approximation. Approximating a multiparticle system in a semiclassical way (mean field theory or a little beyond) gives an approximate deterministic system governing the dynamics of these expectations. This system is highly chaotic at high resolution. This chaoticity seems enough to enforce the probabilistic nature of the measurement apparatus. Neither an underlying exact deterministic dynamics nor an explicit dynamical collapse needs to be postulated.

The same system can be studied at different levels of resolution. When we model a dynamical system classically at high enough resolution, it must be modeled stochastically since the quantum uncertainties must be taken into account. But at a lower resolution, one can often neglect the stochastic part and the system becomes deterministic. If it were not so, we could not use any deterministic model at all in physics but we often do, with excellent success.

This also holds when the resulting deterministic system is chaotic. Indeed, all deterministic chaotic systems studied in practice are approximate only, because of quantum mechanics. If it were not so, we could not use any chaotic model at all in physics but we often do, with excellent success.[/QUOTE]

Arnold Neumaire said:

"

I have my own interpretation.

I call it the the thermal interpretation since it agrees with how one does measurements in thermodynamics (the macroscopic part of QM (derived via statistical mechanics), and therefore explains naturally the classical properties of our quantum world. It is outlined in my slides at http://arnold-neumaier.at/ms/optslides.pdf and the entry ''Foundations independent of measurements'' of Chapter A4 of my theoretical physics FAQ at http://arnold-neumaier.at/physfaq/physics-faq.html#found0 . It is described in detail in Chapter 7 of my book ''Classical and Quantum Mechanics via Lie algebras'' at http://lanl.arxiv.org/abs/0810.1019 . See also the following PF posts:

https://www.physicsforums.com/showthread.php?p=3187039&highlight=thermal#post3187039

https://www.physicsforums.com/showthread.php?p=3193747&highlight=thermal#post3193747

The thermal interpretation

It is superior to any I found in the literature, since it

-- acknowledges that there is only one world,

-- is observer-independent and hence free from subjective elements,

-- satisfies the principles of locality and Poincare invariance, as defined in relativistic quantum field theory,

-- is by design compatible with the classical ontology of ordinary thermodynamics

-- has no split between classical and quantum mechanics,

-- applies both to single quantum objects (like a quantum dot, the sun or the universe) and to statistical ensembles,

-- allows to derive Born's rule in the limit of a perfect von-Neumann measurement (the only case where Born's rule has empirical content),

-- has no collapse (except approximately in non-isolated subsystems).

-- uses no concepts beyond what is taught in every quantum mechanics course,

No other interpretation combines these merits.

The thermal interpretation leads to a gain in clarity of thought, which results in saving a lot of time otherwise spent in the contemplation of meaningless or irrelevant aspects arising in poor interpretations.

The thermal interpretation is based on the observation that quantum mechanics does much more than predict probabilities for the possible results of experiments done by Alice and Bob. In particular, it quantitatively predicts the whole of classical thermodynamics.

For example, it is used to predict the color of molecules, their response to external electromagnetic fields, the behavior of material made of these molecules under changes of pressure or temperature, the production of energy from nuclear reactions, the behavior of transistors in the chips on which your computer runs, and a lot more.

The thermal interpretation therefore takes as its ontological basis the states occurring in the statistical mechanics for describing thermodynamics (Gibbs states) rather than the pure states figuring in a quantum mechanics built on top of the concept of a wave function. This has the advantage that the complete state of a system completely and deterministically determines the complete state of every subsystem - a basic requirement that a sound, observer-independent interpretation of quantum mechanics should satisfy.

The axioms for the formal core of quantum mechanics are those specified in the entry ''Postulates for the formal core of quantum mechanics'' of Chapter A4 of my theoretical physics FAQ at http://arnold-neumaier.at/physfaq/physics-faq.html#postulates . There only the minimal statistical interpretation agreed by everyone is discussed. The thermal interpretation goes far beyond that, assigning states and an interpretation for them to individual quantum systems, in a way that large quantum systems are naturally described by essentially classical observables (without the need to invoke decoherence or collapse). The new approach is consistent with assigning a well-defined (though largely unknown) state to the whole universe, whose properties account for everythng observable within this universe.

The fundamental mathematical description of reality is taken to be standard quantum field theory. It doesn't matter for the thermal interpretation whether or not there is a deeper underlying deterministic level.

In my thermal interpretation of quantum physics, the directly observable (and hence obviously ''real'') features of a macroscopic system are the expectation values of the most important fields Phi(x,t) at position x and time t, as they are described by statistical thermodynamics. If it were not so, thermodynamics would not provide the good macroscopic description it does.

However, the expectation values have only a limited accuracy; as discovered by Heisenberg, quantum mechanics predicts its own uncertainty. This means that <Phi(x)> is objectively real only to an accuracy of order 1/sqrt(V) where V is the volume occupied by the mesoscopic cell containing x, assumed to be homogeneous and in local equilibrium. This is the standard assumption for deriving from first principles hydrodynamical equations and the like. It means that the interpretation of a field gets more fuzzy as one decreases the size of the coarse graining - until at some point the local equilibrium hypothesis is no longer valid.

This defines the surface ontology of the thermal interpretation. There is also a deeper ontology concerning the reality of inferred entities - the thermal interpretation declares as real but not directly observable any expectation <A(x,t)> of operators with a space-time dependence that satisfy Poincare invariance and causal commutation relations.

These are distributions that produce measurable numbers when integrated over sufficiently smooth localized test functions.

Deterministic chaos is an emergent feature of the thermal interpretation of quantum mechanics, obtained in a suitable approximation. Approximating a multiparticle system in a semiclassical way (mean field theory or a little beyond) gives an approximate deterministic system governing the dynamics of these expectations. This system is highly chaotic at high resolution. This chaoticity seems enough to enforce the probabilistic nature of the measurement apparatus. Neither an underlying exact deterministic dynamics nor an explicit dynamical collapse needs to be postulated.

The same system can be studied at different levels of resolution. When we model a dynamical system classically at high enough resolution, it must be modeled stochastically since the quantum uncertainties must be taken into account. But at a lower resolution, one can often neglect the stochastic part and the system becomes deterministic. If it were not so, we could not use any deterministic model at all in physics but we often do, with excellent success.

This also holds when the resulting deterministic system is chaotic. Indeed, all deterministic chaotic systems studied in practice are approximate only, because of quantum mechanics. If it were not so, we could not use any chaotic model at all in physics but we often do, with excellent success.[/QUOTE]

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