Local mechanism for nonlocal anticorrelations inside spin theory

[PeterDonis]

what I mean by 'mechanism' is just something in quantum mechanics

Which makes this discussion pretty pointless; basically you're saying "quantum mechanics is quantum mechanics". True, but hardly worth discussion.

 

[martinbn]

What you are suggesting cannot be true, and the papers themselves say the same thing: there are no correlations between 1 & 4 unless and until the decision is made to execute a swap.

And even then there is no correlation. There is correlation of the results of a subset of the trials.

 

[Fra]

There is no "mechanism" in QM. That's why there is not one single generally accepted interpretation of QM.

Agreed. Or rather there ia no known mechanism behind QM that helps deep understanding of QM weirdness.

But that isnt the same as to say its meaningless to look for one. For some of us a least, the reward at the end of this path of inquiry is not just another "pure interpretation" that makes no difference, but the hope of an interpretation that will guide us into the real open questions regarding unification of forces. This is very different that looking for a "Bell class" HV explanation.

/Fredrik

 

[PeroK]

Well, what I mean by 'mechanism' is just something in quantum mechanics regardless of quantum mechanics.

It's worth noting that the idea of a fundamental mechanism isn't sustainable in physics generally. Newton's second law, to some extent, allows the concept of a mechanism in each case. But, Newton's law of gravity - by Newton's own admission - is purely a mathematical relationship that has no possible underlying mechanism. Likewise, GR has no "mechanism" for the stress-energy tensor determining the geometry of spacetime. And, Maxwell's mathematics, again not a specific mechanism, drives the propagation of EM radiation etc. I believe that 19th physicists were slow to accept Maxwell's EM theory because it wasn't mechanical enough. They, like you, wanted a mechanism; not just mathematics.

And, in general, if we are using a Lagrangian or Hamiltonian approach, then we have a mathematical, rather than a mechanical description of nature at all scales, from the microscopic to the cosmological.

You could argue that QM takes this a stage further, but you are never going to find a mechanism in any sense of the word, with microscopic cogs and wheels and levers, at the core of modern physics.

 

[Fra]

It's worth noting that the idea of a fundamental mechanism isn't sustainable in physics generally.

Agreed, this is one of the arguments in favour of ABM (agent based models) instead of the "Newtoian Scheme" System dynamics. Both are mathematical models, and both paradigms can often model the same phenomenan, but they offert perspectives.

In system dynamics, of course there is no "mechanism" we just have evolution laws on system level.
In Agent based interactions, the mechanism is at the focus, and system dyanmics is emergent.

This point is I think also at the root of Smolin path of inquiry where he argues - against the prevailing paradigm in physics - that we need a paradigm change. Sometime he received also plenty of critique for (not too surprisingly!)

/Fredrik

 

[Morbert]

What do you mean by "local interactions"? Depending on how you interpret that phrase, it could apply to all interpretations, or none.

I mean the same that @DrChinese means: If A and B are spatially distant, an external influence on A cannot have an immediate effect on B.

 

[Morbert]

No, there are no such explanations I have ever seen or heard of - and I’ve seen a lot. What there are a lot of are *claims* of such, and usually they focus on demonstrating equivalence to QM mathematically. A full remote swapping context features 2 separated measurements (violating a Bell inequality) and a third remote spot where a decision can be made (with the free will of the experimenter) to create entanglement or not.

Anyone who can pitch that as local action successfully would be of great interest to me. Just show me a paper with a diagram. :)

Do you take issue with accounts for conventional EPR experiments with local interactions? E.g.

As to the EPRB setup, consider an analogous classical situation: a bomb, initially at rest, explodes into two fragments carrying opposite angular momenta. Alice and Bob, far away from each other, measure arbitrarily chosen components J1 and J2 [...]

The distribution of bomb fragments is given by a Liouville function in phase space. When Alice measures J1, the Liouville function for J2 is instantly altered, however far Bob is from Alice. No one finds this surprising, since it is universally agreed that a Liouville function is only a mathematical tool representing our statistical knowledge. Likewise, the wave function ψ, or the corresponding Wigner function (Wigner, 1932) which is the quantum analogue of a Liouville function, are no more than mathematical tools for computing probabilities.

The essential difference [...] is that the classical Liouville function is attached to objective properties that are only imperfectly known. On the other hand, in the quantum case, the probabilities are attached to potential outcomes of mutually incompatible experiments, and these outcomes do not exist “out there” without the actual interventions. Unperformed experiments have no results.

https://arxiv.org/abs/quant-ph/0212023

A similar exercise can be carried out for your systems of interest, where entanglement is established between photons that have never been close together. You have not accepted such exercises in previous threads, so I think your issue with local accounts is larger than swapping experiments.

 

[DrChinese]

1. Do you take issue with accounts for conventional EPR experiments with local interactions? E.g. https://arxiv.org/abs/quant-ph/0212023

2. A similar exercise can be carried out for your systems of interest, where entanglement is established between photons that have never been close together. You have not accepted such exercises in previous threads, so I think your issue with local accounts is larger than swapping experiments.

1. Of course I take issue with Peres’ description, which he of all people should have known better. First, that’s an old reference (2002) and I keep specifying modern experiments. They didn’t even start those until about 2002. Peres certainly knew of the appropriate theory though at that time, and specifically he well knew of delayed choice options. So I would criticize his description in particular.

Second, that is once again ignoring what I am challenging. Which is: remote swapping.

2. No, claiming a “similar exercise” without detailing further is merely hand waving. The devil is in the details, let’s see those. If this were class, I’d say “show your work”.

 

[physika]

You could argue that QM takes this a stage further, but you are never going to find a mechanism in any sense of the word, with microscopic cogs and wheels and levers, at the core of modern physics.

...what limited language.

Mechanism:
Process by which something takes place by a set of rules/law etc.
(Obviously, describable by mathematics).

....

 

[iste]

there are no correlations between 1 & 4 unless and until the decision is made to execute a swap

Yes, I say this in the post, literally in what you quote. There is no correlation unless you condition on the outcomes via measurement and I explain why that is in the quote.

They are *perfect* correlations, which are only possible with entangled systems.

Yes, the correlations from this model are perfect. Again, This mechanism isn't accounting for everything about photon polarization correlations but they are perfect. If you have two particles, each traveling on orbital motions where they rotate at the rate and the phase shift between them is fixed (e.g. 90 degrees), then you can get perfect anti-correlations in the sense that if you measure one polarized vertically the other one is always going to be horizontal and vice versa, or for any other direction of motion. You can then get two particles moving away from each other, doing their little orbiting spiralling motions as they go and so long as their rotations are not interrupted, you should always gets the same correlations even if they are very far apart. If you do a phase shift by 0 or 180 degrees, then it will always be horizontal-horizontal, vertical-vertical, matched diagonals etc etc.

Where is the local mechanism to address this?

Its just statistical conditioning. If there are perfect anticorrelations (just looking at regular entanglement swapping in general here) then if 2 is H and 3 is H, then 1 and 4 must both be V and there is a perfect relationship between 1 and 4 too. 2 is H, 3 is V? Then 1 is V and 4 is H so there will be another perfect anticorrelation. If you dont condition then 1 & 4 can take on all possible combinations of HH, VV, HV, VH and so you wont see any correlation unless you condition on outcomes of 2 & 3 - then they suddenly become perfect just because you have conditioned statistically on those outcomes. Obviously, experimentally you need to ensure that you can get the correct coincidences.

 

[iste]

There is no "mechanism" in QM. That's why there is not one single generally accepted interpretation of QM. People can "explain" a given QM result with different interpretations that use completely different, inconsistent, and incompatible "mechanisms".

Well, what I mean by 'mechanism' is just something in quantum mechanics regardless of quantum mechanics.

Woops, I meant regardless of interpretation.

 

[iste]

Which makes this discussion pretty pointless; basically you're saying "quantum mechanics is quantum mechanics". True, but hardly worth discussion.

Woops, I didn't even see this.

No, not at all. For instance, you can derive the Schrodinger equation and reproduce all of quantum mechanics from stochastic processes according to stochastic mechanics. Because what is being derived is identical to quantum mechanics, it will not contradict it in anyway and it won't contradict Bell, hence how Stochastic mechanics has been shown recently to be able to reproduce electron spin correlations and Bell violations. However, despite being clearly equivalent, there is the addition of a different underlying interpretation.

So you can analogously give an underlying interpretation of quantum mechanical formalism and experiment, of the phase which is established at source and is important to the eventual measured correlations.

 

[iste]

It's worth noting that the idea of a fundamental mechanism isn't sustainable in physics generally. Newton's second law, to some extent, allows the concept of a mechanism in each case. But, Newton's law of gravity - by Newton's own admission - is purely a mathematical relationship that has no possible underlying mechanism. Likewise, GR has no "mechanism" for the stress-energy tensor determining the geometry of spacetime. And, Maxwell's mathematics, again not a specific mechanism, drives the propagation of EM radiation etc. I believe that 19th physicists were slow to accept Maxwell's EM theory because it wasn't mechanical enough. They, like you, wanted a mechanism; not just mathematics.

And, in general, if we are using a Lagrangian or Hamiltonian approach, then we have a mathematical, rather than a mechanical description of nature at all scales, from the microscopic to the cosmological.

You could argue that QM takes this a stage further, but you are never going to find a mechanism in any sense of the word, with microscopic cogs and wheels and levers, at the core of modern physics.

Personally, I think this is too quick. For me, the existence of stochastic mechanics, the derivation of quantum mechanics from stochastic processes suggests that a kind of mechanistic construction of quantun mechanics is possible in principle.

 

[DrChinese]

Yes, I say this in the post, literally in what you quote. There is no correlation unless you condition on the outcomes via measurement and I explain why that is in the quote.

Yes, the correlations from this model are perfect. Again, This mechanism isn't accounting for everything about photon polarization correlations but they are perfect. If you have two particles, each traveling on orbital motions where they rotate at the rate and the phase shift between them is fixed (e.g. 90 degrees), then you can get perfect anti-correlations in the sense that if you measure one polarized vertically the other one is always going to be horizontal and vice versa, or for any other direction of motion. You can then get two particles moving away from each other, doing their little orbiting spiralling motions as they go and so long as their rotations are not interrupted, you should always gets the same correlations even if they are very far apart. If you do a phase shift by 0 or 180 degrees, then it will always be horizontal-horizontal, vertical-vertical, matched diagonals etc etc.

Its just statistical conditioning. If there are perfect anticorrelations (just looking at regular entanglement swapping in general here) then if 2 is H and 3 is H, then 1 and 4 must both be V and there is a perfect relationship between 1 and 4 too. 2 is H, 3 is V? Then 1 is V and 4 is H so there will be another perfect anticorrelation. If you dont condition then 1 & 4 can take on all possible combinations of HH, VV, HV, VH and so you wont see any correlation unless you condition on outcomes of 2 & 3 - then they suddenly become perfect just because you have conditioned statistically on those outcomes. Obviously, experimentally you need to ensure that you can get the correct coincidences.

Sorry, virtually everything you are saying involves claiming there are local hidden variables. Bell tells us otherwise, which is generally accepted by the physics community.

To be clear: there is no connection whatsoever between 1 and 4 regardless of the polarization measurements of 2 & 3. The only way you get entanglement between 1 & 4 is for 2 & 3 to interact indistinguishably. No interaction - distant to 1 & 4 and optionally delayed - there are no perfect correlations.

Again I say: address an actual experiment all the way though, not via hand waving generalities.

High-fidelity entanglement swapping with fully independent sources
Kaltenback et al (2008)
https://arxiv.org/pdf/0809.3991

See figure 1, noting that distances in this setup are arbitrary. And please, how about addressing my point: there can be no “information update” unless a remote physical interaction occurs between 2 & 3. So obviously something physical does happen remotely, and it’s not simply an information update. Which is why it cannot be statistically conditioned on the outcome at 2 & 3, which can be performed later. Whether there are perfect correlations or not is strictly dependent on whether that physical interaction occurs.

Again: the 2 & 3 outcomes are the same - HH, HV, etc. - regardless of whether that physical interaction occurs. But if it does not occur, there are no perfect correlations. So that is the difference, and why your explanation cannot work.

I ask that you not fall back to old descriptions that do not work for modern experiments. There cannot be the kind of locality you envision given these experiments from the past 15 years or so. Trace through it carefully and you will see what I’m saying is correct. I still have no idea what the mechanism is that underlies this process. But it is just basic QM, and really should not be anything surprising to anybody.

 

[Morbert]

1. Of course I take issue with Peres’ description, which he of all people should have known better. First, that’s an old reference (2002) and I keep specifying modern experiments. They didn’t even start those until about 2002. Peres certainly knew of the appropriate theory though at that time, and specifically he well knew of delayed choice options. So I would criticize his description in particular.

Before we tackle modern experiments, I want to know if you take issue with such accounts of simpler EPR experiments. E.g. Alice and Bob are spatially distant and perform joint measurements on entangled 2-particle systems. The outcomes exhibit Bell-inequality violating correlations. Without worrying about more sophisticated experiments yet, do you believe these simpler experiments cannot be accounted for with local interactions?

 

[DrChinese]

Before we tackle modern experiments, I want to know if you take issue with such accounts of simpler EPR experiments. E.g. Alice and Bob are spatially distant and perform joint measurements on entangled 2-particle systems. The outcomes exhibit Bell-inequality violating correlations. Without worrying about more sophisticated experiments yet, do you believe these simpler experiments cannot be accounted for with local interactions?

I follow the standard explanation that was the norm after Bell’s paper came out: local realism is ruled out. That means locality is a logical possibility when realism is ruled out.

I don’t know if I would use the term “local interactions“ in such a context. But I don’t argue with the general concept of locality as being feasible.

Of course, all of this before the discovery of remote entanglement via swapping. Just as Bell demonstrated something that had existed all along in quantum mechanics, remote swapping. demonstrates something that has also existed all along. Now that we know about entanglement swapping, it is no longer possible to entertain locality as being feasible.

 

[PeterDonis]

you can derive the Schrodinger equation and reproduce all of quantum mechanics

"All of quantum mechanics" is more than the Schrodinger equation.

That said, as far as I can tell, the stochastic interpretation is a recognized interpretation of QM. So you can adopt it as your preferred interpretation.

What you can't do, though, is assert that whatever meaning you want to give to terms like "locality" and "mechanism" based on the stochastic interpretation must also be adopted by everyone else in the discussion. If you read the guidelines for this subforum, you will see that discussions of QM interpretations are not resolvable because different interpretations make inconsistent claims, and you can't just assert that your preferred interpretation is right and all the others are wrong. There is no "right" and "wrong" in the sense of being able to test interpretations vs. each other by experiment; they all make the same predictions for all experimental results. So interpretation discussions are a matter of opinion. Even if your opinion is that the stochastic interpretation provides a "local mechanistic" account of quantum phenomena, others might not share that opinion, and there is no way for you to show that they must share it.

 

[Morbert]

I follow the standard explanation that was the norm after Bell’s paper came out: local realism is ruled out. That means locality is a logical possibility when realism is ruled out.

I don’t know if I would use the term “local interactions“ in such a context. But I don’t argue with the general concept of locality as being feasible.

The first stepping stone at least.

In a traditional EPR experiment, when Alice carries out a measurement on the 2-particle system, she immediately updates relevant probability distributions for outcomes of possible measurements Bob can (or did) perform on the same system. According to Peres, she can do this without invoking nonlocal interactions as she does not interpret these distributions as concerning objective properties of the 2-particle system.

Similarly, in an entanglement swapping experiment, when Alice carries out a BSM involving both 2-particle systems (The 1,2 system and the 3,4 system), she can immediately update distributions for outcomes of possible joint measurements on the 1,4 system without invoking nonlocal interactions as she does not interpret these distributions as concerning objective properties of the 1,4 system.

 

[PeterDonis]

when Alice carries out a BSM

Alice isn't the one who carries out the BSM. Alice and Bob each have photons they will measure, photons 1 and 4, but someone else, Charlie or Victor or whoever, carries out the BSM on photons 2 and 3. And whether or not that BSM gets carried out determines whether Alice and Bob see correlations between their measurements. And this is true even if Alice, Bob, and the location of the BSM are far apart and all of the relevant events are spacelike separated so no light signals can travel between them.

 

[Morbert]

Alice isn't the one who carries out the BSM. Alice and Bob each have photons they will measure, photons 1 and 4, but someone else, Charlie or Victor or whoever, carries out the BSM on photons 2 and 3. And whether or not that BSM gets carried out determines whether Alice and Bob see correlations between their measurements. And this is true even if Alice, Bob, and the location of the BSM are far apart and all of the relevant events are spacelike separated so no light signals can travel between them.

You can adopt any naming convention, so long as the important comparison is made: In the traditional EPR, an observer carries out a measurement and updates distributions re/ possible measurements of the other observer. In the entanglement swapping experiment, an observer carries out a BSM and updates distributions re/ possible joint measurements on the 1,4 system by the other observers.

 

[PeterDonis]

You can adopt any naming convention

The naming convention isn't the issue. The issue is that your description implied that the person who carries out the BSM is the same as one of the people who makes the measurements whose correlations will be assessed. That is not the case.

 

[Morbert]

The naming convention isn't the issue. The issue is that your description implied that the person who carries out the BSM is the same as one of the people who makes the measurements whose correlations will be assessed. That is not the case.

My description did not imply this.

 

[PeterDonis]

My description did not imply this.

It did for anyone who is familiar with the usual naming convention used for these experiments. From your post #55 I now see that you did not intend that implication, but while you say the naming convention isn't the issue, if you pick a naming convention that's different from what's usually used in the literature, you are inviting confusion.

 

[DrChinese]

1. In a traditional EPR experiment, when Alice carries out a measurement on the 2-particle system, she immediately updates relevant probability distributions for outcomes of possible measurements Bob can (or did) perform on the same system. According to Peres, she can do this without invoking nonlocal interactions as she does not interpret these distributions as concerning objective properties of the 2-particle system.

2. Similarly, in an entanglement swapping experiment, when Alice carries out a BSM involving both 2-particle systems (The 1,2 system and the 3,4 system), she can immediately update distributions for outcomes of possible joint measurements on the 1,4 system without invoking nonlocal interactions as she does not interpret these distributions as concerning objective properties of the 1,4 system.

1. What you are saying makes no sense, and to the extent you say it represents Peres’ views I reject it completely. It is the joint expectation value that is important, and that is strictly a function of a joint context. A nonlocal context…

2. Similarly, this literally makes no scientific sense. What Alice knows after her kind of measurement (on 1) is precisely nothing about 4. And has absolutely no connection of any kind to 4 unless an experimenter elsewhere makes a decision to entangle it with 4. You know, an experimenter who is far away and is… not local.

 

[iste]

"All of quantum mechanics" is more than the Schrodinger equation.

That said, as far as I can tell, the stochastic interpretation is a recognized interpretation of QM. So you can adopt it as your preferred interpretation.

What you can't do, though, is assert that whatever meaning you want to give to terms like "locality" and "mechanism" based on the stochastic interpretation must also be adopted by everyone else in the discussion. If you read the guidelines for this subforum, you will see that discussions of QM interpretations are not resolvable because different interpretations make inconsistent claims, and you can't just assert that your preferred interpretation is right and all the others are wrong. There is no "right" and "wrong" in the sense of being able to test interpretations vs. each other by experiment; they all make the same predictions for all experimental results. So interpretation discussions are a matter of opinion. Even if your opinion is that the stochastic interpretation provides a "local mechanistic" account of quantum phenomena, others might not share that opinion, and there is no way for you to show that they must share it.

I didn't say stochastic mechanics is right, I just stated my disagreement that in principle mechanistic explanations are not sustainable. I just gave an example which is no different from the examples in the post I was replying to - if you can derive quantum mechanics from a "mechanistic" perspective then surely that is a counterexample.

Also, none of the conversations I have had in this thread involving 'mechanisms' and 'locality' have been from a stochastic perspective at all. Nothing in the original post of the thread is a stochastic perspective.

 

[iste]

Sorry, virtually everything you are saying involves claiming there are local hidden variables. Bell tells us otherwise, which is generally accepted by the physics community.

Well fair enough since the description is not complete.

To be clear: there is no connection whatsoever between 1 and 4 regardless of the polarization measurements of 2 & 3.

Yes, I say this is the case and explain why that is the case in the text you quoted.

The only way you get entanglement between 1 & 4 is for 2 & 3 to interact indistinguishably.

Yes, which is just a means of performing the measurement on the photons so you can attain coincidences to condition on.

See figure 1, noting that distances in this setup are arbitrary. And please, how about addressing my point: there can be no “information update” unless a remote physical interaction occurs between 2 & 3. So obviously something physical does happen remotely, and it’s not simply an information update. Which is why it cannot be statistically conditioned on the outcome at 2 & 3, which can be performed later. Whether there are perfect correlations or not is strictly dependent on whether that physical interaction occurs.

Again: the 2 & 3 outcomes are the same - HH, HV, etc. - regardless of whether that physical interaction occurs. But if it does not occur, there are no perfect correlations. So that is the difference, and why your explanation cannot work.

From my perspective, a measurement projecting onto the Bell state is just more or less equivalent to statistical conditioning and since that is all that is really involved, there is nothing more to it than statistical conditioning.

Again: the 2 & 3 outcomes are the same - HH, HV, etc. - regardless of whether that physical interaction occurs. But if it does not occur, there are no perfect correlations. So that is the difference, and why your explanation cannot work.

Yes, because you cannot establish coincidences or do statistical conditioning until measurement given that Bell state measurement is just statistical conditioning and requires the establishment of coincidences via coherence in order to do so. I mean, this is obviously why independent sources need to be time-synchronized.

 

[Morbert]

1. What you are saying makes no sense, and to the extent you say it represents Peres’ views I reject it completely. It is the joint expectation value that is important, and that is strictly a function of a joint context. A nonlocal context…

Then my initial suspicion was correct. You do not accept such accounts of even traditional EPR experiments, never mind entanglement swapping experiments.

In the traditional EPR experiment, if we interpret all relevant distributions as about objective properties of the measured system, imperfectly known, then the Bell-inequality-violating correlations reproduced by joint measurements on the 2-particle system imply* one measurement immediately affects the site of the other, distant measurement .

If, on the other hand, we interpret all relevant distributions as about outcomes of possible measurements, and hence relax counterfactual definiteness, then the Bell-inequality-violating correlations reproduced by joint measurements on the system no longer imply one measurement immediately affects the site of the other, distant measurement.

What is your precise objection to this? Entanglement swapping scenarios are hard to address productively until this more foundational issue is resolved.

* Leaving aside topics like superdeterminism

 

[Fra]

Sorry, virtually everything you are saying involves claiming there are local hidden variables. Bell tells us otherwise, which is generally accepted by the physics community.

The implict assumptions in bells theorem has been discussed before in many threads and they aren't all obvious.

Bell type hidden variables aren't the only logical possibility to "hidden mechanism" with some sort of "hidden variables" to explain correlation. They were ineded a possibility of early investigation - and this possibility was nicely disproven via Bells theorem.

But the original inquiry is still there!

The term hidden variable or mechanism has been poisoned, as those terms are lumped with the resistnace against QM.

Can we call it "hidden parameter in a non-classical model" and keep focusing on the original inquiry, to IMPROVE our undertanding of QM? Even in a weird game of expectations, there are "mechanisms", but maybe of different kinds that are not best understood in the newtonian paradigm.

About "old descriptions that do not work for modern experiments" I will just note that Quantum mechanics as well as QFT are STILL in the newtonian paradigm.

My opinion is that it is even worse: I think the old paradigm do not work for understanding the nature of interactions in the quantum domain.

/Fredrik

 

[Nugatory]

But the original inquiry is still there!

From that perspective, Bell's Theorem isn't saying that we cannot find a "mechanism", but rather that if we ever do it will necessarily be as offensive to our classical intuition as QM already is. That seems to me a defensible proposition, although it may imply a broader definition of "mechanism" than many people are assuming.

However

I will just note that Quantum mechanics as well as QFT are STILL in the newtonian paradigm.

Here you have lost me, probably because my definition of that paradigm is more restrictive than yours. I understand it to include that effects have causes (constrained by relativity) and counterfactual definiteness, and I do not see how to reconcile these with Bell-violating QM.

 

[PeterDonis]

Alice knows after her kind of measurement (on 1)

In Morbert's terminology, Alice is the one who does the BSM, not the one who measures photon #1. I agree this is not well chosen terminology on his part. See my post #58.

 

[PeterDonis]

none of the conversations I have had in this thread involving 'mechanisms' and 'locality' have been from a stochastic perspective at all. Nothing in the original post of the thread is a stochastic perspective.

Then you are not adopting the stochastic interpretation as your preferred interpretation--which means that, according to the guidelines of this subforum, you should not be mentioning it at all. You need to pick an interpretation and stick to it. If you are not picking the stochastic interpretation, which interpretation are you picking?

From my perspective, a measurement projecting onto the Bell state is just more or less equivalent to statistical conditioning and since that is all that is really involved, there is nothing more to it than statistical conditioning.

This is a straightforward statistical interpretation, which is fine, but it's not the stochastic interpretation. So if this is the interpretation you are picking, you need to stick to it and stop mentioning the stochastic interpretation.

That said, everything in my earlier post still applies if you are picking the statistical interpretation, because @DrChinese is not using that interpretation. His preferred interpretation is one in which QM has to explain the results of individual runs of an experiment, not just the statistics over many runs. So what you are saying simply does not apply to the interpretation he is using. And, as I pointed out earlier, there is no way to resolve that, because which intepretation you pick is a matter of personal preference and opinion; there is no way to test it by experiment. So you and he are basically talking past each other.

 

[PeterDonis]

Bell type hidden variables aren't the only logical possibility to "hidden mechanism" with some sort of "hidden variables" to explain correlation. They were ineded a possibility of early investigation - and this possibility was nicely disproven via Bells theorem.

If you claim there is another possibility, you need to give a reference that describes what it is. You can't just wave your hands and gesture in the direction of a possibility that you can't even show is actually realized.

 

[PeterDonis]

You do not accept such accounts of even traditional EPR experiments

Yes, as I pointed out to the OP in post #66, the interpretation @DrChinese is using does not accept such accounts even of traditional EPR experiments. You appear to be using a statistical interpretation, which does; but @DrChinese is not.

 

[Morbert]

Yes, as I pointed out to the OP in post #66, the interpretation @DrChinese is using does not accept such accounts even of traditional EPR experiments. You appear to be using a statistical interpretation, which does; but @DrChinese is not.

I am inferring a stronger claim from @DrChinese. A claim that is not interpretation dependent: Any interpretation that can account for entanglement swapping experiments must involve actions having immediate effects in spatially distant regions.

@DrChinese If you are simply making an interpretation-dependent claim about local action, then there isn't disagreement between us. I agree that some interpretations suppose nonlocal action, while others do not.

 

[DrChinese]

From my perspective, a measurement projecting onto the Bell state is just more or less equivalent to statistical conditioning and since that is all that is really involved, there is nothing more to it than statistical conditioning.

Yes, because you cannot establish coincidences or do statistical conditioning until measurement given that Bell state measurement is just statistical conditioning and requires the establishment of coincidences via coherence in order to do so. I mean, this is obviously why independent sources need to be time-synchronized.

The idea that the Bell State Measurement (BSM) on 2 & 3 is “statistical conditioning” has been experimentally rejected. The BSM requires physical interaction between 2 & 3. That physical interaction is manifested by indistinguishability of the 2 and 3 photons. Those two must arrive near simultaneously at the beam splitter to enable them to interact. If one of the photons is delayed, then it will be distinguishable from the other. If the photons are not indistinguishable, then the entanglement swap fails. Please reference the following experiment, also from a Zeilinger team.

https://arxiv.org/pdf/1203.4834

Check out figure 3, the A chart shows Entangled state statistics when there is indistinguishability. The B chart shows Separable state statistics when there is not such indistinguishability because a delay was inserted, preventing the two photons from interacting as part of the BSM.

This experiment was performed in 2012. It has been replicated by other papers and teams. This is an application of standard quantum mechanics. Note that while there is synchronization between the independent sources, this does not cause any special entanglement or related Entangled state statistics.