Quantum Interpretation Poll (2011)

In summary, the conversation discusses an annual quantum interpretation poll where one can vote for their preferred interpretation of reality. The poll is missing the consistent histories interpretation and does not have a way to specify details for "other". The thermal interpretation of quantum mechanics is brought up and the speaker provides links to further information on this interpretation, including its benefits and its compatibility with classical thermodynamics. The thermal interpretation is based on the observation that quantum mechanics predicts classical thermodynamics and takes as its ontological basis the states occurring in statistical mechanics. The thermal interpretation also addresses the issue of uncertainty in quantum mechanics and defines a surface ontology and a deeper ontology.

Which Quantum Interpretation do you think is correct?

  • Copenhagen Interpretation

    Votes: 34 22.7%
  • GRW ( Spontaneous Collapse )

    Votes: 2 1.3%
  • Consciousness induced Collapse

    Votes: 11 7.3%
  • Stochastic Mechanics

    Votes: 3 2.0%
  • Transactional Interpretation

    Votes: 4 2.7%
  • Many Worlds ( With splitting of worlds )

    Votes: 12 8.0%
  • Everettian MWI (Decoherence)

    Votes: 18 12.0%
  • de-Broglie Bohm interpretation

    Votes: 17 11.3%
  • Some other deterministic hidden variables

    Votes: 15 10.0%
  • Ensemble interpretation

    Votes: 13 8.7%
  • Other (please specify below)

    Votes: 21 14.0%

  • Total voters
    150
  • #1
Fyzix
173
2
I think it's time for the annual quantum interpretation poll.

Vote for which interpretation you currently think represents reality.
 
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  • #2
Fyzix said:
I think it's time for the annual quantum interpretation poll.

Vote for which interpretation you currently think represents reality.

Since this seems to be an annual poll, could you please link to the poll's result of the last few years?

Consistent histories interpretations are missing.
Also, there is no way to specify the details for ''other'' (last button).
 
  • #3
Just search of quantum interpretations, there seems to have been like 20 of them, but I decided to call this annual so it can be the offical one of 2011 and not be moved to the philosophy section.

Yeah I forgot consistent histories, but isn't it just copenhagen really?
There is collapse and it's indeterministic.

Specify details for other here in the thread.
 
  • #4
The thermal interpretation of quantum mechanics

Fyzix said:
Just search of quantum interpretations, there seems to have been like 20 of them, but I decided to call this annual so it can be the offical one of 2011 and not be moved to the philosophy section.

Could you please list the few most recent of these?

Fyzix said:
Yeah I forgot consistent histories, but isn't it just copenhagen really?
There is collapse and it's indeterministic.
It is not Copenhagen, else it would not have its own name.

Fyzix said:
Specify details for other here in the thread.
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.
 
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  • #5
I don't really understand the difference between "Many Worlds (With splitting of worlds)" and "Everettian MWI (Decoherence)".

In case we have two classical scenarios (e.g. Schrödinger's cat, coin tossing, ...) decoherence explains why we always observe one of these two classical scenarios instead of a quantum superposition. But decoherence does NOT explain why we observe exactly THIS scenario. It explains why the cat is either dead or alive. But if there IS a dead cat it does NOT explain why the cat dead, not alive.

There is another ingredient required, e.g. MWI with random splitting of worlds.

Am I wrong?
 
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  • #6
That "thermal interpretation" sounds cool ;-)

just a quick (maybe annoying) question, is QM linear in the thermal interpretation?
 
  • #7
unusualname said:
That "thermal interpretation" sounds cool ;-)

just a quick (maybe annoying) question, is QM linear in the thermal interpretation?

Of course. Everything valid in standard quantum mechanics and quantum field theory remains valid in the thermal interpretation. In particular, the Schroedinger equation holds without any modification.
 
  • #8
tom.stoer said:
I don't really understand the difference between "Many Worlds (With splitting of worlds)" and "Everettian MWI (Decoherence)".

Both items look strange.

Many worlds makes no sense without splitting of worlds.

Decoherence has _nothing_ to do with the much older Everett interpretation, though it can be combined with it. But it is no independent interpretation since it needs either the statistical interpretation or some form of MWI to get off ground.

Also ''Copenhagen'' comprises very different interpretations depending on who defines it.

And De Broglie--Bohm is today usually called Bohmian mechanics.
To be meaningful, each selectable item should be accompanied by a paragraph explaining what is meant by it, with a positive list and a negative list of features.

Maybe it would be better to collect a list of features of which the various interpretations combine some of these, and ask to indicate which of these features are present or absent in each participant's own view.
 
  • #9
A. Neumaier said:
Of course. Everything valid in standard quantum mechanics and quantum field theory remains valid in the thermal interpretation. In particular, the Schroedinger equation holds without any modification.

i assume you mean the Schrödinger Evolution eqn, which is a postulate of QM (maybe unfairly named), not the non-relativistic Schrödinger eqn, which has limited applicability.

Hmm, I like the overall philosophy, might be worth studying the book in more detail :smile:

@OP, people are not really that into thinking along the lines of "interpretations" any more, there are fundamental issues like discreteness of space-time to consider before you can commit to any of the old-fashioned interpretations. I agree with A.Neumaier that consistent histories, or any model that includes decoherence is considered most plausible, but as I say there are fundamental issues which require resolution before a commitment to a QM "interpretation" can be made.
 
  • #10
unusualname said:
i assume you mean the Schrödinger Evolution eqn, which is a postulate of QM (maybe unfairly named), not the non-relativistic Schrödinger eqn, which has limited applicability.
The Schroedinger equation i hbar psidot = H psi is valid universally in (conservative) quantum mechanics. This includes the relativistic case and quantum field theory, where H is the generator of time translations of the Poincare group.
unusualname said:
Hmm, I like the overall philosophy, might be worth studying the book in more detail :smile:
You are welcome!
 
  • #11
A. Neumaier said:
The Schroedinger equation i hbar psidot = H psi is valid universally in (conservative) quantum mechanics. This includes the relativistic case and quantum field theory, where H is the generator of time translations of the Poincare group.

You are welcome!

Yes, some people don't realize that the Schrödinger Evolution equation is valid universally even in qft, this is due to undergraduate introductions to QM where everyone learns the non-relativistic equation with Schrödinger's name, the evolution law should perhaps be called the Heisenberg-Schrödinger eqn.
 
  • #12
unusualname said:
Yes, some people don't realize that the Schrödinger Evolution equation is valid universally even in qft, this is due to undergraduate introductions to QM where everyone learns the non-relativistic equation with Schrödinger's name, the evolution law should perhaps be called the Heisenberg-Schrödinger eqn.
I think it is due do the fact that (because of renormalization issues) books on relativistic QFT don't talk about time evolution but only about the S-matrix. The whole formalism looks so different from QM that it seems to be a completely different subject.

See https://www.physicsforums.com/showthread.php?t=476412 for a discussion of this.
 
  • #13
tom.stoer said:
I don't really understand the difference between "Many Worlds (With splitting of worlds)" and "Everettian MWI (Decoherence)".

In case we have two classical scenarios (e.g. Schrödinger's cat, coin tossing, ...) decoherence explains why we always observe one of these two classical scenarios instead of a quantum superposition. But decoherence does NOT explain why we observe exactly THIS scenario. It explains why the cat is either dead or alive. But if there IS a dead cat it does NOT explain why the cat dead, not alive.

There is another ingredient required, e.g. MWI with random splitting of worlds.

Am I wrong?

Well the difference is that MWI with splitting, means literally physical copies of the universe at each measurement...

To check out the difference: http://plato.stanford.edu/entries/qm-everett/
 
  • #14
A. Neumaier said:
I think it is due do the fact that (because of renormalization issues) books on relativistic QFT don't talk about time evolution but only about the S-matrix. The whole formalism looks so different from QM that it seems to be a completely different subject.

See https://www.physicsforums.com/showthread.php?t=476412 for a discussion of this.

Yeah, that thread reminds me of why I don't think you've quite got it right. But as i say I like the overall philosophy but can't partake in an exchange of exactly why i think you're wrong since:

1 it would make the thread go against the founding rules of the forum
2 I can't be arsed since I haven't quite established my own thinking yet, and until then I would not be able to reply to your sophisticated mathematical arguments with due clarity.
 
  • #15
lack;
Consistent Histories, Modal Approach, Two-State Vector Formalism, Relational Interpretation.
 
  • #16
2 for Copenhagen?
Who?
 
  • #18
Let's go ensemble interpretation! If enough people vote I believe that, on average, we will win and everything will make perfect sense, no matter how odd things may seem with only these few votes cast.
 
  • #19
I have recently seen a paper : Mathematical model I. Electron and quantum mechanics.
AIP Advances 1, 012105 (2011); doi:10.1063/1.3559460.
Online Publication Date: 1 March 2011.

The paper deals with only the preliminary aspects of quantum mechanics. Still, I believe that the approach may lead to some understanding of the phenomenon (to some extent) in classical manner. Such attempts may be discussed and debated.

As there is no classical interpretation option, I have voted for “Other”.
 
  • #20
I voted for other.

If we stick to the pure interpretations, I still think the old Copenhagen interpretation is nice. The main problem is it assumes a classical observer (which is merely a limiting case in my view).

So my interpretation of QM is that the strucutre of QM as it stands, is merely an effective description of a generalisation. This means that I think QM needs to be modified. This more general intrinsic rational inference as I'd like to call it would give the current QM framework in a limit of am infinitely complex observer observing a small subsystem of it's own environment. This is also effectively exactly the domain where all current particle and atomic physics does apply.

In particular will this "scheme" fail badly for cosmological models, and for any model where the subsystem constraint doesn't apply. This I believe, can not be cured just be "interpretations". The mathematical model of the measurement theory needs to be generealized.

This is why my interpretation is not a pure interpretation, it's combined with an ambition that QM will need generalisation.

/Fredrik
 
  • #21
unusualname said:
Can you learn the friggin forum etiqutette and post links to abstracts you silly person

I am not silly, and resent being labelled as such. Unless you apologize, this was my last response to a posting by you.
 
  • #23
The many worlds interpretation based on nothing but the fact that i believe it makes each individual invincible and little else.
 
  • #24
Why isn't "Shut up and calculate" on the list?

The vast majority of working physicists don't care about interpretations (at least in my experience), don't know much about them (some will have heard of the Copenhagen interpretation and MWI, but usually from reading pop-sci books when they were young), and/or don't consider them scientifically meaningful (unless someone comes up with a way to test them experimentally).

It is not a topic covered in most QM courses, and unless you end up working on e.g. foundations of QM you are very unlikely to come across different interpretations in the course of your work.

Part of my work is on decoherence mechanism in solid state QIP so I do read/discuss decoherence and "preserving quantumness" quite a lot; but the various interpretations simply never come up.
Personally I don't feel the need for an interpretation, I can use QM to design. model and analyze my experiments which is enough for me.
 
  • #25
I'm somewhat astonished that there's so many (non-Bohmian) hidden variable theorists around! I'd love it if some of you could share what flavour of hidden variables floats your boat...
 
  • #26
A. Neumaier said:
I am not silly, and resent being labelled as such. Unless you apologize, this was my last response to a posting by you.

Missed this above, yes I suppose it wasn't very polite, sorry for any offense, I thought it was kind of cute at the time, but I can see how it comes across as just plain rude.

As regards responding to my posts, well they're usually low content obvious observations and thoughts that don't require much discussion so don't worry :smile:
 
  • #27
I voted "other". There seems to be plethora of interpretations based on determinism, but since I'm currently leaning towards the universe being a fundamentally random place (in a non-ensemble way), there are not that many options available.
 
  • #28


A. Neumaier said:
Could you please list the few most recent of these?


It is not Copenhagen, else it would not have its own name.


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.

Hi,

1. How does your model explain the double slit experiment? In between emission and detection.. what is the electron or buckyball doing? How come they can shoot this one at a time and after many hours or days, interference patterns still show up?

2. How does your model explain Bell's Theorem at 30 Billion light years correlation?

3. How does quantum tunneling work? Is your particle always a particle or does it shapeshift between wave or particle?

Feynman said the double slit is the only mystery. If one can solve it. Then everything is solved. So pls. don't forget to explain well the double slit experiment.
 
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  • #29


Don't quote more than is necessary to understand your questions or comments!

rogerl said:
1. How does your model explain the double slit experiment? In between emission and detection.. what is the electron or buckyball doing? How come they can shoot this one at a time and after many hours or days, interference patterns still show up?

2. How does your model explain Bell's Theorem at 30 Billion light years correlation?

3. How does quantum tunneling work? Is your particle always a particle or does it shapeshift between wave or particle?

Feynman said the double slit is the only mystery. If one can solve it. Then everything is solved. So pls. don't forget to explain well the double slit experiment.

The double slit experiment and the formation of particle tracks are
discussed from the point of view of the thermal interpretation in
the PhysicsForums thread
What does the probabilistic interpretation of QM claim?
https://www.physicsforums.com/showthread.php?t=480072

For Bell's theorem, see
http://arnold-neumaier.at/ms/lightslides.pdf

Quantum tunneling works like classical tunneling for a stochastic process. There is nothing mysterious in it.
 
  • #30


A. Neumaier said:
In that series of slides you write on p. 57-58,
Since the quantum mechanics of a single photon is that of the Maxwell equations, the experiment can be explained by the classical Maxwell equations, upon interpreting the photon number detection rate as being proportional to the beam intensity.

This is a classical description, not by classical particles (photons) but by classical waves.

Thus a classical wave model for quantum mechanics is not ruled out by experiments demonstrating the violation of the traditional hidden variable assumptions.

Therefore the traditional hidden variable assumption only amounts to a hidden classical particle assumption.

And the experiments demonstrating their violation only disprove classical models with particle structure.
It seems to me you completely misunderstand Bell's proof here. The proof deals with any theory where the specification of the state of a region of spacetime can be broken down into a set of local facts about the state of each point--what Bell called local "beables"--and where the state at each point in space and time can only be causally influenced by local states in the past light cone of that point. This would certainly apply to classical field theories like classical electromagnetism!

From another thread, here was my definition of what "local realism" means in the context of Bell:
1. The complete set of physical facts about any region of spacetime can be broken down into a set of local facts about the value of variables at each point in that regions (like the value of the electric and magnetic field vectors at each point in classical electromagnetism)

2. The local facts about any given point P in spacetime are only causally influenced by facts about points in the past light cone of P, meaning if you already know the complete information about all points in some spacelike cross-section of the past light cone, additional knowledge about points at a spacelike separation from P cannot alter your prediction about what happens at P itself (your prediction may be a probabilistic one if the laws of physics are non-deterministic).
With an additional comment about 1), if it's ambiguous what it means to say "broken down into a set of local facts":
Keep in mind that 1) doesn't forbid you from talking about "facts" that involve an extended region of spacetime, it just says that these facts must be possible to deduce as a function of all the local facts in that region. For example, in classical electromagnetism we can talk about the magnetic flux through an extended 2D surface of arbitrary size, this is not itself a local quantity, but the total flux is simply a function of all the local magnetic vectors at each point on the surface, that's the sort of thing I meant when I said in 1) that all physical facts "can be broken down into a set of local facts". Similarly in certain Bell inequalities one considers the expectation values for the product of the two results (each one represented as either +1 or -1), obviously this product is not itself a local fact, but it's a trivial function of the two local facts about the result each experimenter got.
Would you agree that 1) and 2) would cover classical field theories? If so it's not too hard to show that this alone is sufficient to derive Bell inequalities using arguments about the past light cones of the two regions of spacetime where experiments are performed and how specification of all local facts in the cross-section of one region's past light cone can "screen off" any correlations with facts about the other region, see my summary in [post=3248153]this post[/post] along with the link to the paper by Bell that explains the argument in more detail. If you don't find the argument convincing, perhaps we could discuss it in more detail...
 
  • #31


JesseM said:
In that series of slides you write on p. 57-58,

It seems to me you completely misunderstand Bell's proof here. The proof deals with any theory where the specification of the state of a region of spacetime can be broken down into a set of local facts about the state of each point--what Bell called local "beables"--and where the state at each point in space and time can only be causally influenced by local states in the past light cone of that point. This would certainly apply to classical field theories like classical electromagnetism!

His particles are local but e/m waves are not.

My slides contain a setting in which the Bell inequalities can be violated although everything is described by the classical Maxwell equations. So whatever Bell's arguments are, they cannot be valid in this setting.
JesseM said:
If you don't find the argument convincing, perhaps we could discuss it in more detail...
Please open a new thread for that...
 
  • #32


A. Neumaier said:
Please open a new thread for that...
OK, discussion continued on this thread.
 
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  • #33
Yeahhhh, voted! Only the 2nd person to choose that option, too. Out of a total of 33 votes so far.
 
  • #34
unusualname said:
Missed this above, yes I suppose it wasn't very polite, sorry for any offense, I thought it was kind of cute at the time, but I can see how it comes across as just plain rude.

It is easier to add missing information by just giving it, rather than by adding further derisive comments.

By the way, www.scholar.google.com refers like me to the arXiv pdf's rather than to the abstracts.
 
  • #35


A. Neumaier said:
I have my own interpretation.

The thermal interpretation 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.

A discussion forum for discussing the thermal interpretation has been approved:
https://www.physicsforums.com/showthread.php?t=490492
Please post your comments there.
 

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