New work by Tim Palmer and Sabine Hossenfelder

[Joy Christian]

* The CHSH expression E(AB) − E(AB') + E(A'B) + E(A'B') <= 2, contains a mixture of two actual expectation values and two counter-factual expectation values.

I don't undersatnd this. There can be only one actual expectation value among the four, and three conuterfactual expectaion values.

Hi Joy, because E(AB), E(A'B') do not share any terms. But you are right, the derivation actually implies only a single actual and 3 counterfactual expectation values.

Thanks, Michel.

The mistake in Bell's theorem is completely transparent. If you have one elephant and three horses in a race, then you can't assume that they are all the same and treat them equally, unless you are a statistician.

I am writing yet another critique of Bell's theorem. I hope it will be short and devastating.

***

[Heinera]

The mistake in Bell's theorem is completely transparent. If you have one elephant and three horses in a race, then you can't assume that they are all the same and treat them equally, unless you are a statistician.

I am writing yet another critique of Bell's theorem. I hope it will be short and devastating.
***

I wish John Bell was still alive, so you could personally explain his error to him using elephants and horses, like he was a five year old child.

[Joy Christian]

The mistake in Bell's theorem is completely transparent. If you have one elephant and three horses in a race, then you can't assume that they are all the same and treat them equally, unless you are a statistician.

I am writing yet another critique of Bell's theorem. I hope it will be short and devastating.
***

I wish John Bell was still alive, so you could personally explain his error to him using elephants and horses, like he was a five year old child.

I also wish John Bell was still alive. And if he were, then I would have certainly explained his error to him using elephants and horses, and he would have listened to me very patiently.

Unfortunately, the last time I was able to communicate with him was just about eight months before he passed away:


***

[Heinera]

Did you get the job?

[Joy Christian]

Did you get the job?

No. I got a Research Fellowship at Oxford and worked on a quantum gravity problem suggested by Sir Roger Penrose instead.

***

[gill1109]

* The CHSH expression E(AB) − E(AB') + E(A'B) + E(A'B') <= 2, contains a mixture of two actual expectation values and two counter-factual expectation values.

I don't understand this. There can be only one actual expectation value among the four, and three conuterfactual expectaion values.

Hi Joy, because E(AB), E(A'B') do not share any terms. But you are right, the derivation actually implies only a single actual and 3 counterfactual expectation values.

Thanks, Michel.
The mistake in Bell's theorem is completely transparent. If you have one elephant and three horses in a race, then you can't assume that they are all the same and treat them equally, unless you are a statistician.
I am writing yet another critique of Bell's theorem. I hope it will be short and devastating.

We statisticians can do amazing things which nobody else understands! But they do need us. That's why they hate us, that's why they ridicule us. Ha, ha, ha!!! (evil laughter)

In the CHSH expression, *all four random variables* are counter-factual random variables. (According to classical physics, they exist, and some of them, sometimes, do get observed). All four expectation values are expectations of products of counterfactual variables.

You are forgetting the part of the proof of Bell's theorem (classical physics is incompatible with quantum physics) where we prove that E(AB) is equal to the expectation value of the product of two observable random variables in a particular, factually possible, experiment.

[gill1109]

One of my favourite short proofs of Bell's theorem goes as follows. Sorry, it is a bit long.

Says everything. What you showed is not a proof of Bell's theorem but of Bell's inequalities. But I don't think these days anyone is interested in proofs of Bell's inequalities because there is little doubt that the inequalities are valid. The question is about the meaning of the inequalities and whether they are applicable to EPR-type experiments, and what they mean for physics.

So sorry, contrary to the claim, you haven't proved Bell's theorem.

Please read what I wrote! I did not prove Bell's inequality. Bell's inequality is an exercise to the reader in Boole's book from the 1850's. I think any schoolchild could come up with it themselves, nowadays.

I showed the difficult part of the proof of Bell's theorem -- the theorem which establishes the incompatibility of quantum and classical physics. The easy part of the proof is the QM calculation of the singlet correlations. Bell's theorem is a theorem about physical theories. In other words, it is metaphysics. What do those physical theories mean for physics (what do they say about physical reality?)?

Well, as Bell himself said, Bohr would have said "I told you so". What Bell's theorem means for physics depends on your "interpretation" of quantum physics, ie, it depends on your meta-physics, on your philosophy. It depends on what you mean by "physical reality", what you mean by "real". It might even depend on what you mean by "mean".

[Joy Christian]

***
There is a big difference between mathematics and physics. And there is a much bigger difference between statistics and physics. Knowing a bit of statistics does not help you with physics.

Here is a parody of a quote from John S. Bell himself that explains that difference very well (I have replaced "von Neumann" with [ Bell ]):

Yet the [ Bell ] proof, if you actually come to grips with it, falls apart in your hands! There is nothing to it. It is not just flawed, it is silly! ...When you translate [ his assumptions ] in terms of physical disposition they’re nonsense. You may quote me on that: The proof of [ Bell ] is not merely false but foolish!

I will attempt to illustrate this fact lucidly in my upcoming new critique of Bell's theorem.

***

[Jarek]

Even simpler - you just need to dissatisfy this single assumption: "there exists joint probability distribution on Omega".
It is really easy with Ising model thanks to using nearly the same math (Feynman -> Boltzmann path ensemble) - instead of probability on Omega, as in QM states are defined by amplitudes on Omega, which have to be added for unmeasured variables, then multiplied to get probabilities.

Hi Jarek,
See this post from a few years ago, for an explanation why there is no joint probability distribution (ABC) in the EPR experiment viewtopic.php?f=6&t=181. Again, I'm not familiar with the Ising model but the very nature of the EPR experiment makes the existence of a joint probability distribution an exception rather than the rule.

Also, these article goes into a lot more detail about why the lack of such a distribution should be expected:
https://arxiv.org/abs/0907.0767
http://www.panix.com/~jays/vorob.pdf

There is however a subtlety that we should never lose sight of, and that a lot of people miss repeatedly. Although the lack of such a probability distribution can invalidate the applicability of such inequalities there are situations in which the probability distribution could be imagined to exist but the distribution used in the derivation is different than the one measured in actual experiments. The coin toss example I gave above illustrates this succinctly, how a mathematical relation can be derived using one distribution, and an experiment sampling a different distribution would appear to violate it. I also recently posted an illustration from category theory to show why this is the case in experiments like the EPR. You can find it here viewtopic.php?f=6&t=373&p=8529p8529#p8529

There are a few undeniable facts:

* The CHSH expression E(AB) − E(AB') + E(A'B) + E(A'B') <= 2, contains a mixture of two actual expectation values and two counter-factual expectation values. This is simply what the derivation demands by considering what might be imagined.
* For set of particle pairs, it is impossible measure all the particle pairs at angles (a,b,a',b') simultaneously. Thus, in the experimental data, there is no joint measurement of of outcomes (A, A', B, B'). In practice, 4 disjoint paired distributions (A, B), (A, B'), (A', B), (A', B') are sampled.
* As Vorob proved, it is not always possible to reconstruct a joint distribution for (A, A', B, B') from such separate disjoint distributions, even one could be imagined to exist. See my post viewtopic.php?f=6&t=181 for an explanation why. Also note that when calculating E(AB) − E(AB') + E(A'B) + E(A'B') from an experiment, what matters is ONLY the fact that such a distribution exists in the experimental data not whether the distribution can be imagined to exist. In short, imaginary experimental data does not exist.

Hi Minkwe,
Sure, I have no doubts that QM can dissatisfy this single "there exists joint probability distribution on Omega" assumption leading to inequalities which can be violated by physics - by somehow using "there exists amplitude on Omega" instead - to be added over unmeasured variables, then multiplied in Born rule.
What we really need in understanding this difference: how can we dissatisfy the first assumption, replacing it with the latter.

Also for other successfully used theories like general relativity - why it doesn't lead to contradiction: does not satisfy this assumption leading to inequalities violated by physics?
So is there "probability distribution on Omega" in general relativity?
In Bell it is crucial that it has to exist before measurement, but general relativity is solved with time-symmetric: Einstein equation.
So we have symmetric boundary condition here: before and after measurement - we have two amplitudes on Omega instead of probability distribution.

Ising model is a high school level math, the most basic model of condensed matter physics - just Boltzmann distribution among sequences.
But it already has all these issues: amplitudes instead of probability distribution on Omega - Born rule allowing for Bell violation.
Exactly as in Feynman path integrals formulation: current situation comes from meeting of propagators from past and future, each carrying separate amplitude, as in TSVF https://en.wikipedia.org/wiki/Two-state ... _formalism

We need simplified models to understand complex physics - Ising is perfect for Born/Bell issues thanks to using nearly the same math (Feynman -> Boltzmann path ensemble), but in more intuitive setting: spatial instead of temporal direction.
Or if someone would like to really understand special relativity, I definitely recommend sine-Gordon ( https://en.wikipedia.org/wiki/Sine-Gordon_equation ) - it is looking trivial PDF (f_tt = f_xx - sin(f)), but already has "massive particles" with rest mass(energy) scaling exactly as in special relativity, energy released in annihilation, also having Lorentz contraction and time dilation (slowing oscillating solutions when gaining velocity).

[minkwe]

Sure, I have no doubts that QM can dissatisfy this single "there exists joint probability distribution on Omega" assumption leading to inequalities which can be violated by physics - by somehow using "there exists amplitude on Omega" instead - to be added over unmeasured variables, then multiplied in Born rule.
What we really need in understanding this difference: how can we dissatisfy the first assumption, replacing it with the latter.

This is not surprising, the path integral formalism and even Lagrangian mechanics also uses mathematical trickery like like that. Problems only arise when you ascribe physical existence to mathematical entities that should be understood only as tricks used for solving problems.

The Hess & De Raedt article address this explicitly https://arxiv.org/abs/0907.0767

The “probability” to measure a particle by the given equipment with given setting is then related by Born’s interpretation to the absolute square (a positive number) of the wave function that thus assigns a positive number to an event once the actual type of measurement is chosen. This assignment, however, can not yet be regarded as a probability measure in the spirit of Boole or in terms of Kolmogorov’s definitions because there is no assignment made at this point for a sample space, i.e. a space of all possible outcomes and corresponding elementary events or logical elements. The Born rule appears thus as a pre-measure that may be expanded to a full Kolmogorov probability measure only after all experiments of a sequence are chosen i.e. once all macroscopic equipment configurations of measurements and all possible outcomes (data) are fully determined. If we desire to create a Kolmogorov frame model based on Born’s rule, then the actual choice of random variables may also necessitate the introduction of one or more stochastic processes in order to include time coordinates that are otherwise not included in the Kolmogorov framework.

Also for other successfully used theories like general relativity - why it doesn't lead to contradiction: does not satisfy this assumption leading to inequalities violated by physics?
So is there "probability distribution on Omega" in general relativity?

This is an important question. The answer is simple though. You don't find hundreds of online forums where people are debating interpretations of general relativity. You may ask, why? The answer to this question is the same answer to your question -- Because general relativity is a theory that was derived from general principles based on a clear ontology. QM on the other hand was arrived at by cobbling together mathematical ideas based on trial-and-error in order to arrive at the right answer without any clear ontology.

Jayne was one of the authors who understood this problem very well https://bayes.wustl.edu/etj/articles/backward.look.pdf

As we have noted in some detail elsewhere (Jaynes, 1991), throughout the history of quantum theory, whenever we advanced to a new application it was necessary to repeat this trial-and-error experimentation to find out which method of calculation gives the right answers. Then, of course, our textbooks present only the successful procedure as if it followed from general principles; and do not mention the actual process by which it was found. In relativity theory one deduces the computational algorithm from the general principles. In quantum theory, the logic is just the opposite; one chooses the principle to fit the empirically successful algorithm.

But after all, how can one build rationally from a theory whose basic principles are in this condition: Present quantum theory uses relativistic wave equations, but tries to solve them with propagators that -- quite aside from the divergences -- violate relativity by failing to vanish outside the light-cone, and run backward in time! What can this possibly mean?

On a more elementary level, present quantum theory claims on the one hand that local micro-events have no physical causes, only probability laws; but at the same time admits (from the EPR paradox) instantaneous action at a distance! Today we have in full flower the blatant, spooky contradictions that Einstein foresaw and warned us about 60 years ago, and there is no way to reason logically from them. This mysticism must be replaced by a
physical interpretation that restores the possibility of thinking rationally about the world.

In Bell it is crucial that it has to exist before measurement, but general relativity is solved with time-symmetric: Einstein equation.
So we have symmetric boundary condition here: before and after measurement - we have two amplitudes on Omega instead of probability distribution.

Be careful with your use of the word "exist", what do you mean by "exist"? Measurement results can't exist before the measurement that produces them. This should be obvious.

We need simplified models to understand complex physics - Ising is perfect for Born/Bell issues thanks to using nearly the same math (Feynman -> Boltzmann path ensemble), but in more intuitive setting: spatial instead of temporal direction.

If it takes the same approach as path integrals ( math first, and physics later), I would be very doubtful. But on the other hand if there is a better understanding of how the Ising model arises from a clear ontology using general principles, then it may be helpful. I don't know enough about it at this point to say either way.

[gill1109]

Speaking for myself, I don't know what the word "exists" means. That is a question which has been studied for thousands of years by philosophers. I do know that there is no consensus among philosophers on this question. You write, Michel,

Be careful with your use of the word "exist", what do you mean by "exist"? Measurement results can't exist before the measurement that produces them. This should be obvious.

It is great for you that it is obvious to you! But the question of whether or not it is obvious is actually the whole question here. The question which Einstein and Bohr fought about, which the EPR paper tried to address, which intrigued John Bell, and which is still debated today. In particular, here. If the measurement results which will be obtained when a certain measurement is done are merely functions of what certainly does exist, can't we say that they exist too? If x exists, and the function f exists, doesn't f(x) also exist? What does "exist" mean, anyway? Maybe there are different kinds of existence. Physical, mathematical, emotional, conceptual, ... Inge Helland talks about c-variables. They exist conceptually but not physically, nor, as far as I know, mathematically. He has published a book and a lot of articles about this concept https://arxiv.org/abs/0801.2026.

[minkwe]

Speaking for myself, I don't know what the word "exists" means.

Then try to find out before you use the word yourself to avoid contradictions that would reveal you don't know what you are talking about.

It is obvious and should be obvious to anyone with common sense that the outcome of an experiment does not exist until the experiment is actually performed. What alternatives do you want to entertain? That the outcomes of the experiment exist before the experiment is performed, or that even after performing the experiment the outcomes do not exist? What exactly are you suggesting the disputing this clear fact?

Funding agencies who spend billions on research funding understand this, otherwise they won't spend a dime on a single experiment -- if the outcomes already exist why do you need any money?

Some truths sometimes appear too trival for those who think they are too smart to focus on trivial things.

BTW, the Einstein Bohr debates was definitely not about when experimental outcomes come into existence. You definitely mis-characterized the EPR paper. It was about the relationship between the physical concepts underlying a theory and the object reality that the physical theory is trying to model.

[gill1109]

Speaking for myself, I don't know what the word "exists" means.

Then try to find out before you use the word yourself to avoid contradictions that would reveal you don't know what you are talking about.

It is obvious and should be obvious to anyone with common sense that the outcome of an experiment does not exist until the experiment is actually performed. What alternatives do you want to entertain? That the outcomes of the experiment exist before the experiment is performed, or that even after performing the experiment the outcomes do not exist? What exactly are you suggesting the disputing this clear fact?

Funding agencies who spend billions on research funding understand this, otherwise they won't spend a dime on a single experiment -- if the outcomes already exist why do you need any money?

Some truths sometimes appear too trival for those who think they are too smart to focus on trivial things.

BTW, the Einstein Bohr debates was definitely not about when experimental outcomes come into existence. You definitely mis-characterized the EPR paper. It was about the relationship between the physical concepts underlying a theory and the object reality that the physical theory is trying to model.

Michel, you are talking about the common-sense meaning of the word "exist". People working in the foundations of physics mean other things. Tim Palmer and Sabine Hossenfelder understand me. The Einstein Bohr debate was about the completeness of quantum theory. Einstein was sure that the randomness of the outcomes of experiments described in quantum theory was merely the reflection of randomness or uncertainty in a deeper level of description of an essentially deterministic nature.

Bell noticed that such theories already existed (the de Broglie pilot-wave theory had been around for a long time, and David Bohm gave it new life in the 50s). There were others (GRW, CSL...). These models all perfectly reproduce QM predictions. However, he also noticed that they shared non-local characteristics, which is exactly why they did not become popular, though they did have some following, and still do. In fact, right now experimenters have figured out experimentally accessible phenomena which some of those models do predict, and have done experiments which rule out some of them.

BtW, I don't think I am very smart. I do think that everyone has their own strengths and own weaknesses.

[Jarek]

This is not surprising, the path integral formalism and even Lagrangian mechanics also uses mathematical trickery like like that. Problems only arise when you ascribe physical existence to mathematical entities that should be understood only as tricks used for solving problems.

Lagrangian formalism is not just "mathematical trickery", but mathematics we successfully use in all scales like classical mechanics, electromagnetism, general relativity, QFT.
Do you know any other way we successfully describe fundamental behavior of physics?

The difference between physics and faith/theology is that while in the latter we basically give up the search, in the former we believe in nature working in a systematic way - that its behavior can be decomposed into our mathematical description: physics ... for which in practice we use Lagrangian formalism.
Are there any phenomena suggesting that not everything in physics can be decomposed into such mathematical description?

The problematic quantum mechanics is literally between these Lagrangian formalisms we use - e.g. QED is electromagnetism + QM.
But electromagnetism is a hidden variable theory - all information is in its EM field, so it is its "hidden variable".
All Lagrangian formalism like EM, QED are realistic - assume that there "exists" the object described by this formalism like field.
They are also local in sense of finite propagation speed.

So what does Bell theorem disprove here?
How there can exist e.g. the field, but not probability distribution?
Ising is a great toymodel to see that this is exactly what's happening - due to symmetry, we don't have one probability distribution, but two: amplitudes (from left and right) on Omega instead of Bell's single probability distribution.

Bell disproves solving all these theories in asymmetric way like Euler-Lagrange (requiring superdeterminism to fully use them).
Fortunately we have also another way, which is not disproven: solving CPT-symmetric physics in symmetric way: least action principle, Feynman path/diagram ensemble.
Is there a third option, not disproven by Bell?

How does nature works?

[minkwe]

Lagrangian formalism is not just "mathematical trickery", but mathematics we successfully use in all scales like classical mechanics, electromagnetism, general relativity, QFT.

But it is. The fact that it works to give us the right answers in physics does not change this. It is perfectly fine to use such trickeries so long as keep in mind that the mathematical tricks we use to process is quite distinct from the the objective reality we are trying to model.

Do you know any other way we successfully describe fundamental behaviour of physics?

I don't. In fact I'm not suggesting a different model but a better understanding of the meaning of the current ones. I can describe the position and motion of an object in a Cartesian basis, but I can also describe the position of an object in a polar basis. Which one is real? They are both just mathematical tricks that work. The fact that both allow us to get the right answers means that they are just similar ways of describing an underlying reality that is independent of either approach. The same with Lagrangian mechanics, Newtonian mechanics, quantum mechanics etc. You get into problems when you focus on the mathematical entities within each framework and attempt to ascribe objectiveness to them. This is the root of all current problems in the interpretation of QM.

..we believe in nature working in a systematic way - that its behavior can be decomposed into our mathematical description: physics ... for which in practice we use Lagrangian formalism.
Are there any phenomena suggesting that not everything in physics can be decomposed into such mathematical description?

You are asking the wrong questions. An alien civilization may come up with it's own scientific language for describing physical phenomena, in such a way that gives the same right answers, but appears quite different from our current mathematics and physical theories. Are you suggesting that this is impossible? On what basis? Our current mathematics and theories are by-products of our culture and history. And we don't have any basis to suggest that we have discovered everything that can be learned even within our own mathematical language. We are often guilty of the "Mind Projection Fallacy" when we think the models are themselves the objective reality (https://bayes.wustl.edu/etj/articles/prob.as.logic.pdf). They just models we have invented, that work. When we stop looking for better models, and criticize anyone who suggests better models may exist, we are practising religion not physics.

So what does Bell theorem disprove here?
How there can exist e.g. the field, but not probability distribution?
Ising is a great toymodel to see that this is exactly what's happening - due to symmetry, we don't have one probability distribution, but two: amplitudes (from left and right) on Omega instead of Bell's single probability distribution.

Because the field itself is a mathematical tool not a "thing" that exists out there objectively. But as I've explained already, Bell's theorem is not valid because the inequalities do not apply to the situations it is commonly applied to. The reasons have been clearly explained in my previous posts. The so called bell's theorem has been a stumbling block to progress.

Bell disproves solving all these theories in asymmetric way like Euler-Lagrange (requiring superdeterminism to fully use them).
Fortunately we have also another way, which is not disproven: solving CPT-symmetric physics in symmetric way: least action principle, Feynman path/diagram ensemble.

Bell doesn't disprove anything. Even the principle of least action just as with all variational methods, is a mathematical trick, not an objective physical entity. You have to properly understand how it relates to the ontology, in order to avoid mystical properties. How does the particle that is moving, know which path is going to be the one with least action? Is it, as some have suggested, the ridiculous idea that it simultaneously tries out all possible paths?

[Jarek]

minkwe,

If you see mathematics we successfully use to model/predict nature as just a "mathematical trickery", so what better do you propose?
Let say construct a radio using only wisdom of philosophers?

I don't. In fact I'm not suggesting a different model but a better understanding of the meaning of the current ones.

Exactly, aren't the current ones mainly Lagrangian formalism I am asking about? - like classical mechanics, electromagnetism, general relativity, QFT.
All of them assume there exists e.g. field (realism) containing all relevant information, evolve it with finite propagation speed (locality) - why Bell theorem do not disprove them?[b]

You are asking the wrong questions. An alien civilization may come up with it's own scientific language for describing physical phenomena

Sure, while nature is universal, there is some freedom of details/perspectives for physics/mathematics to describe it.
However, there are also objective questions with universal answers - hypothetical aliens would answer in analogous ways, like dependencies between atoms in periodic table.

Another example for [b]yes/no universal question: "is nature fundamentally time/CPT symmetric", there should be one objective answer - also for hypothetical aliens.
Trying to answer 'no', all working theories lead to inequalities violated by nature - contradiction.

How does the particle that is moving, know which path is going to be the one with least action? Is it, as some have suggested, the ridiculous idea that it simultaneously tries out all possible paths?

Great question - let's look at it from perspective of Ising model, in which mathematically we assume that physics "tries out all possible" sequences/configurations - weighting them in Botlzmann instead of Feynman way.
So this is statistical mechanics - in reality physics randomly perturbs the configuration space, leading to Boltzmann ensemble as the safest/statistically dominant for fixed energy - due to mathematically universal (also for aliens) Jaynes maximal uncertainty principle: https://en.wikipedia.org/wiki/Principle ... um_entropy

So Boltzmann sequence ensemble in space is effective statistical/mathematical description of some complex behavior.
QM is Feynman path ensemble in time - according to general relativity, we live in spacetime, could transform between space and time e.g. below black hole horizon ... so maybe this is again just analogous effective statistical/mathematical description of some complex behavior.

I am definitely not saying that path ensembles are fundamental description, only that Bell theorem has ruled out asymmetric ways of solving local realistic models like general relativity, leaving the symmetric ways, like: the least action principle, Einstein's equations, path/diagram ensembles, TSVF, meeting of propagators from both time directions.

We don't even try to solve general relativity in asymmetric way like Euler-Lagrange: "unrolling" evolving geometry of spacetime sounds like a nonsense.
Instead, we treat spacetime as static "4D jello" - satisfying local intrinsic curvature (tension) Einestein's equation - solving it in symmetric way.

[JohnDuffield]

I looked at your work, John, but I'm afraid you talk about a lot of physics about which I know so little, that what you write is presently beyond me.

It shouldn't be. If you start at the beginning with [url="http://physicsdetective.com/the-nature-of-time/"]the nature of time[/url], you can appreciate that time is just a cumulative measure of motion. You can then appreciate the next essay, which is [url="http://physicsdetective.com/the-speed-of-light/"]the speed of light is not constant[/url]. Einstein said this repeatedly, year after year. After that you can understand [url="http://physicsdetective.com/how-gravity-works/"]how gravity works[/url]. Einstein explained most of it, and I think it's simpler than you think.

But I do keep on trying to educate myself... I think that QM is telling us that space-time is continually being created in the present, on the boundary between past and future. Waves collapse and particles have to decide where to be, thus creating the distribution of mass in space, in the past. The past is history, the future is a mystery; today is a gift. (You could say: the present is a present). Belavkin used to say: the past is particles, the future is a wave. Well, this is just poetry, or nonsense; not physics and not mathematics.

I don't share your view on that I'm afraid. I consider myself a "relativist", but I also think spacetime is an abstract thing. There's no motion in spacetime because it models space at all times. Spacetime is the map, but the map is not the territory. We live in a world of space and motion. IMHO it's a world full of waves, and some of those waves are in closed paths and look like standing fields. Photon momentum is resistance to change in motion for a wave propagating linearly at c. Electron mass is resistance to change-in-motion for a wave going round and round at c. Et cetera. Again I think it's simpler than you think.

Sorry I haven't replied before now. I've been working away from home, and haven't been taking my personal laptop away with me.

[JohnDuffield]

This is an important question. The answer is simple though. You don't find hundreds of online forums where people are debating interpretations of general relativity. You may ask, why? The answer to this question is the same answer to your question -- Because general relativity is a theory that was derived from general principles based on a clear ontology. QM on the other hand was arrived at by cobbling together mathematical ideas based on trial-and-error in order to arrive at the right answer without any clear ontology.

I agree with this.

[minkwe]

If you see mathematics we successfully use to model/predict nature as just a "mathematical trickery", so what better do you propose? Let say construct a radio using only wisdom of philosophers?

You are not getting it. I'm not proposing anything "better". I'm proposing that we understand that the models as just that -- "models"! And not deceive ourselves into thinking that our models are nature. I think you need a paradigm shift to see what I'm saying.

Exactly, aren't the current ones mainly Lagrangian formalism I am asking about? - like classical mechanics, electromagnetism, general relativity, QFT.
All of them assume there exists e.g. field (realism) containing all relevant information, evolve it with finite propagation speed (locality) - why Bell theorem do not disprove them?[b]

Yes, by assuming the presence of a field in the model, they can do all kinds of predictions and it appears to work quite well. This absolutely does not mean that the "field" is a thing that exists in nature, or that nature is a field. There are other models that do not use fields and also arrive at the same correct answers. It may be easier to use fields but all that proves is the fact that it is a mathematical trick that works better. You can model a mutli-pendulum with Newton's equations, it will be very complicated but you will get the correct answer. You can do the same using Lagrangian mechanics and it will be much easier to get the correct answer. Does that mean nature is like the Lagrangian mechanics, rather than the other model. Absolutely not. It tells you that Lagrangian mechanics is a better mathematical trick for solving these types of problems. Again, it is humans who are trying to solve the problems, not nature.

Sure, while nature is universal, there is some freedom of details/perspectives for physics/mathematics to describe it.

Descriptions are entirely human activities that live in the realm of epistemology. Of course there is a lot of freedom in how we describe things. In fact, our descriptions have evolved over human history. But the descriptions themselves are not nature, and nature is not bound by how we chose to describe it.

However, there are also objective questions with universal answers - hypothetical aliens would answer in analogous ways, like dependencies between atoms in periodic table.

Give me an example, without using a concept that was invented by humans. How do you know hypothetical aliens will even have periodic tables. All those concepts are human inventions.

Another example for [b]yes/no universal question: "is nature fundamentally time/CPT symmetric", there should be one objective answer - also for hypothetical aliens.Trying to answer 'no', all working theories lead to inequalities violated by nature - contradiction.

That question is meaningless. CPT symmetry applies to theories, not to nature. What ontology do you ascribe to CPT symmetry. Do you know of anyone who has ever observed time symmetry? Or is it sufficient to you that if you can imagine time going backwards, the laws that govern the theories will work just the same. Aren't you projecting what you can imagine in your mind as if it is nature?

How does the particle that is moving, know which path is going to be the one with least action? Is it, as some have suggested, the ridiculous idea that it simultaneously tries out all possible paths?

Great question - let's look at it from perspective of Ising model, in which mathematically we assume that physics "tries out all possible" sequences/configurations - weighting them in Botlzmann instead of Feynman way.

First the statement 'physics "tries out all possible" sequences' is quite unfortunate. What do you mean by "physics", the particle, nature, ..., what exactly? But you admit you are just thinking mathematically, so we may let that one go.

So this is statistical mechanics - in reality physics randomly perturbs the configuration space, leading to Boltzmann ensemble as the safest/statistically dominant for fixed energy - due to mathematically universal (also for aliens) Jaynes maximal uncertainty principle: https://en.wikipedia.org/wiki/Principle ... um_entropy

There is so much that is troubling about this statement that I don't even know where to start. Statistical mechanics is a method we have invented to reason about physical systems when we are interested in macro properties but do not have sufficient information about the micro properties. Then you say "physics randomly pertubs the configuration space". How can physics do anything? How does this "physics" relate back to the particle we are talking about. You have to be more clear what you mean. A configuration, is a collection of information about something. The configuration space, is a space of various possible configurations. It is a concept that lives entirely in the human mind as we manipulate information. When you "perturb" configuration space, you are manipulating information in your mind or in an equation. A Boltzmann ensemble is a probability distribution, again a concept from statistical mechanics that involves how we organise and manipulate information in our minds or equations. Maximum entropy principle is again an entirely epistemological concept that helps us to pick the probability distribution which best represents our current state of knowledge. Nothing about any of this deals with nature at all. So sorry, there is no way that this even begins to attempt to answer the question of how the particle knows which path has the least action. You are talking about epistemological concepts as if they are real things. But you are not alone in making this blunder. You have good company.

So Boltzmann sequence ensemble in space is effective statistical/mathematical description of some complex behavior.
QM is Feynman path ensemble in time - according to general relativity, we live in spacetime, could transform between space and time e.g. below black hole horizon ... so maybe this is again just analogous effective statistical/mathematical description of some complex behavior.

This makes no sense to me. Sorry.

I am definitely not saying that path ensembles are fundamental description, only that Bell theorem has ruled out asymmetric ways of solving local realistic models like general relativity, leaving the symmetric ways, like: the least action principle, Einstein's equations, path/diagram ensembles, TSVF, meeting of propagators from both time directions.

Bell's theorem has not ruled out anything. But at this point I think you have bigger problems than Bell's theorem. But this is not a personal criticism. In fact, many articles published in so-called top journals suffer from the same problems.

[Jarek]

There are other models that do not use fields and also arrive at the same correct answers.

General relativity describes shape of spacetime using field of local intrinsic curvatures, waves of this field are now observed e.g. in LIGO. Electromagnetism assumes that in every point and time we have values of electric and magnetic field. Feynman diagrams are results of perturbative expansion of quantum field theories ... all are assumed to be governed by Lagrangian formalism. Between EM and QED there is QM using another field - waveunction.

How would you like to describe them not using fields? In what EM, gravitational waves propagate?

How do you know hypothetical aliens will even have periodic tables.

Atoms in our galaxy or maybe universe have the same properties - hypothetical aliens would get similar classification into atoms and their properties, but sure it would have different units and details which are not universal.

Do you know of anyone who has ever observed time symmetry?

In physics we decompose into microscopic events, and this lowest level (QFT) is proven to have CPT symmetry - from https://en.wikipedia.org/wiki/CPT_symmetry :
[qoute]The CPT theorem says that CPT symmetry holds for all physical phenomena, or more precisely, that any Lorentz invariant local quantum field theory with a Hermitian Hamiltonian must have CPT symmetry. [/quote]
Do you know any microscopic process which has not such symmetry?
In QM we have unitary (reversible) evolution beside wavefunction collapse - is it reversible ... yes it is, for example:
excited atom <-> deexcited atom + photon
I believe you also have experienced this time symmetric process, e.g. atoms in a light-bulb being excited, then deexcited.

A Boltzmann ensemble is a probability distribution, again a concept from statistical mechanics that involves how we organise and manipulate information in our minds or equations. Maximum entropy principle is again an entirely epistemological concept that helps us to pick the probability distribution which best represents our current state of knowledge.

Oh, these are sooo much more than just human concepts, I am information theory person and could talk about their universality for hours ... for example looking at star's spectrum, it agrees with black body radiation https://en.wikipedia.org/wiki/Planck%27s_law - derived from Boltzmann distribution.

Maximum entropy principle is pure mathematics, e.g. having a sequence of n 0/1 values, the number of sequences with p percentage of '1' is asymptotically exp(n * h(p)) where h(p) = -p ln p - (1-p) ln(1-p) Shannon entropy (simple derivation using Stirling formula).
So asymptotically (n -> infinity) the entropy maximizing p=1/2 sequence will dominate all - this is the safest assumption from pure combinatorics.