A new realistic stochastic interpretation of Quantum Mechanics

[iste]

Apologies late reply and that this is long. I just always want to ensure I am being clear.

What?? That is exactly the opposite of b. How can a superposition yield definite values on all bases simultaneously? And even if they could, how do those values appear when measured on a specific basis such that it follows quantum statistics if they are to be called "localized". (Whatever that is supposed to mean in this context, since c. above implies exactly the opposite.)

Because in Barandes' formulation, the definite outcomes or configurations the system are in do not appear in the traditional objects of quantum mechanics like wave-functions, density matrices, etc.

First, to clarify generally:

For statistical systems you might distinguish 1) the probability space / random variables, which carry statistical information; from 2) the realized outcomes. (I will be repeating these two numbers a lot in this post so these are what I mean when I say them). At any time, a statistical system could be said to produce a definite outcome which is a physical event; like if you roll a dice, you always only get one number at a given time. The long-run behavior of that dice rolling is described by probability spaces and random variables but these just predict the actual realizations when you repeat the scenario indefinitely. The objects of 1) therefore are not the physical events themselves that appear in a particular time or place - probability spaces are abstract constructs for prediction. The actual physical events are the objects of 2), the actual realized outcomes i.e. what happens when you actually throw the dice a single time.

Back to Barandes' formulation:

His papers essentially translate between stochastic matrices and a Hilbert Space representation to dress up a stochastic process in the quantum formalism. Importantly, only 1) is being translated. Virtually all of the traditional objects of quantum mechanics are coming from 1) which do not represent physical events.

All of the fundamental results about non-locality and contextuality are therefore concerning objects of 1) when they have been dressed up in quantum formalism. Now, from Barandes' formulation you can also translate quantum mechanics back into a generalized stochastic framework. So what is going to happen? Well nothing is being changed about the information in quantum mechanics, only the formalism is changed. Therefore contextuality and non-locality are preserved when described in the stochastic framework; but now, in addition, you will have these definite realized outcomes since all that has happened is we have translated quantum objects back into objects of probability spaces / random variables, and these will give realized outcomes that were not explicit in the traditional quantum formalism.

Superpositions will therefore not have definite values on all bases simultaneously like you say - they will be the same as normal quantum mechanics. But they will ALSO realize definite outcomes which can be seen when you translate the quantum system into a stochastic one and are not observable from looking at the objects of quantum mechanics in the same way that I cannot see my realized outcome for rolling a 4 at t5 just by looking at the probabilities for rolling a 4.

In fact, I can talk about probability spaces and random variables without ever explicitly talking about the realized outcomes. The fact I rolled a particular number at t4 and another at t8 is immaterial to the description at the level of random variables and probability spaces. All the things I can prove wrt to probability theory don't rely on specific realized outcomes. So there is no reason why introducing realized outcomes should change anything about the quantum formalism. Its just the fact that you can translate it back into the formalism of a stochastic system implies it has definite outcomes at any particular time which are predicted from probability spaces, though not in as straightforward away as for conventional Markov systems which is the way people tend to think about stochastic systems.

The coherences of superposition in this formulation is information, even if more implicitly, about long-run statistics, not about any actual physical event that exists in a specific time and place. There is therefore no contradiction here in exactly the same way that having a probability distribution for dice rolls does not contradict definite realized outcomes every time we roll a dice. The fact that superposition does not look like a normal classical probability distribution is a red herring because we are talking about a special (well actually, generalized) kind of stochastic system.

Admittedly they don't exist in orthodox QM. After Bell, this is explicitly ruled out! You cannot have such outcomes - well they are even outcomes as they aren't measured - and also say it will agree with the predictions of QM. They call that...hand-waving.

Yes, like I say, this is because quantum mechanics is only about 1) which are not physical events or objects in Barandes' formulation. 2) only becomes apparent when you translate the quantum system into a stochastic one. Everything Bell said applies to this translated stochastic system... because all of these formal results are about 1), which are just statistics. There is therefore no contradiction between the notions of a system displaying both contextuality and non-local statistics in 1), which then also realizes definite outcomes of 2). Nothing Bell says rules out anything about 2).

So stochastic systems exhibit nonlocal behavior but feature no nonlocality? Or what?

The generalized stochastic systems in Barandes' papers and quantum systems will both display non-local behavior in that they are both equivalent to each other.

Yes, if there is some nonlocal mechanism here that keeps entangled systems synchronized or otherwise in some kind of contact when their spatial extent grows, then all is good and I am satisfied. But that is not what I am reading.

Barandes demonstrates that you can get the kind of non-local behavior of quantum mechanics by just constructing a generalized stochastic system. He doesn't explicitly say how, just that it does naturally occur in the generalized stochastic system.

My view is that it can be explained following from results like Fine's theorem. Bell violations are equivalent to the absence of joint probability distributions. From what I can see, the indivisibility condition Barandes' uses as a prominent part of defining a generalized stochastic system does correspond to the absences of joint probability distributions which are directly related to Bell violations. As I noted before, this is of a formal nature and so no special physical mechanisms are required, just the inability to construct a context-invariant joint probability distribution. That doesn't mean the systems are not entirely well-defined, just not on a single probability space.

2. How can anyone say with a straight face that they are presenting something novel, it's just like QM only better, and then blatantly ignore the obvious hurdles of things like swapping and GHZ.

a. Swapping: Systems become entangled without ever existing in a common local region. You think that is a "stochastic" result? I don't think that does very far as an argument.

b. GHZ: The assumption that particles have pre-existing values for observables yields predictions that are diametrically opposed to experiment in each and every case?

Barandes' formulation should be able to recreate all GHZ and entanglement swapping phenomenon because the core of these papers is just a "dictionary" which one can use to translate between quantum and stochastic formalisms whilst retaining all of the same behavior and properties. I don't see why it shouldn't work in the same for these cases even though they may seem particularly strange.

I can't say much else without being too speculative but it maybe worth noting a secondary point that the equivalence between Bell violations and absent joint probability distributions suggests that the crucial factor above all else is just incompatible observables. This paper even suggests that entanglement isn't strictly required for Bell violations:

https://arxiv.org/abs/1907.02702

GHZ, PBR*, Kochen-Specker-Bell, Leggett, Hardy...

*Psi-epistemic is a common term for "the wavefunction is clearly not physically real". Directly disproven by PBR.

Again, Barandes' formulation implies that any quantum scenario displaying behaviors typified by these results can just be translated into a stochastic system. Nothing different to standard quantum mechanics is implied.

From my understanding, the root of all these examples is contextuality as expressed in the absence of joint probability distributions, and this does seem to be a prominent assumption in Barandes' formulation where it is also responsible for quantum interference.

Finally, going back to an earlier point you said:

Statistical outcomes are dependent on a future context, even when the measurement setting are changed midflight and are far distant. That's good, dozens of experiments show this exact point. It also means that particle observables don't have definite values outside of when they have an eigenvalue.

This phenomena is not so weird in stochastic interpretations as implied by Barandes' formulation. The particle is set on a trajectory and its configuration is always randomly changing over. Therefore, at a point in time just before it is measured, it will be in a different configuration to what it will be when the measurement interaction eventually happens. Similarly, the configuration at both these time points will be different to the particle's configuration at the beginning of its trajectory. Its always changing. The particle is always in a definite configuration and has a definite trajectory but the configuration just changes randomly at every time point on the trajectory. Obviously the only configuration seen by the experimenter is the one that is eventually measured. The quantum state, the wavefunction are not physical objects but solely carry statistical information. Because the eventual measured configuration randomly occurs at the point of measurement, it is not correct to say that outcomes depend on a future context in this formulation because that assumes the particle was only ever in one configuration decided at the beginning of its trajectory. At the point of measurement, the observed outcome will occur randomly according to a joint probability distribution that depends on the measurement setting there and then. The absence of context-invariant joint distribution then implies Bell violations under Fine's theorem due to the non-commutativity between measurement settings which is sufficient to preclude a joint distribution even though the measured pairs commute.

 

[iste]

1. Don't make me laugh at these ridiculous contrived examples.

Im not implying these are the same as quantum mechanics, just that Bell-type violations are generic which implies a common cause, and that is the absence of unique joint probability distributions. They may be different in all kinds of different scenarios. For instance, I believe the ones in those papers violate Tsirelson's bound which cannot happen in quantum mechanics.

 

[iste]

For example, PBR says nothing, as far as I can see, that rules out ensemble or statistical interpretations

This is how the Barandes' formulation is treating the Wave function.

"One [assumption] is that a system has a “real physical state” – not necessarily completely described by quantum theory, but objective and independent of the observer. ... Nonetheless, this assumption, or some part of it, would be denied by instrumentalist approaches to quantum theory, wherein the quantum state is merely a calculational tool for making predictions concerning macroscopic measurement outcomes."

I want to emphasize that when I say definite realized outcomes here I am talking in the same way that a random variable can realize a specific outcome, but a single outcome won't tell you anything about the probabilities of a random variable. Only repeating the scenario many times and looking at the frequencies will give you some idea of the probabilities. The quantum state / wavefunction plays the same role as probabilities there. They aren't referring to a specific event, their information can only become apparent empirically over many many repetitions of some scenario.

 

[DrChinese]

1. Apologies late reply and that this is long. I just always want to ensure I am being clear.

Finally, going back to an earlier point you said:

DrChinese: "Statistical outcomes are dependent on a future context, even when the measurement setting are changed midflight and are far distant. That's good, dozens of experiments show this exact point. It also means that particle observables don't have definite values outside of when they have an eigenvalue."


2. This phenomena is not so weird in stochastic interpretations as implied by Barandes' formulation. The particle is set on a trajectory and its configuration is always randomly changing over. Therefore, at a point in time just before it is measured, it will be in a different configuration to what it will be when the measurement interaction eventually happens. Similarly, the configuration at both these time points will be different to the particle's configuration at the beginning of its trajectory. Its always changing. The particle is always in a definite configuration and has a definite trajectory but the configuration just changes randomly at every time point on the trajectory. Obviously the only configuration seen by the experimenter is the one that is eventually measured. The quantum state, the wavefunction are not physical objects but solely carry statistical information. Because the eventual measured configuration randomly occurs at the point of measurement, it is not correct to say that outcomes depend on a future context in this formulation because that assumes the particle was only ever in one configuration decided at the beginning of its trajectory. At the point of measurement, the observed outcome will occur randomly according to a joint probability distribution that depends on the measurement setting there and then. The absence of context-invariant joint distribution then implies Bell violations under Fine's theorem due to the non-commutativity between measurement settings which is sufficient to preclude a joint distribution even though the measured pairs commute.

1. You're good - time's no problem.

2. Sure, I get the idea. They have definite values at all times but are dynamic. That is quite similar to the Bohmian concepts where there are ongoing influences ("pilot waves"). But for everything to work out, there must be contextuality. And that requires FTL influences - and I mean explicit ones - to make sense. There can be no hiding behind the mask of a local stochastic interpretation.

"...its configuration is always randomly changing..." Because that directly conflicts with the idea that you end up with perfect correlations after measurement settings are remotely changed midflight and the entangled particles are distant (considering c) - and have never interacted in any manner.

You can't have it both ways. @Demystifier (our resident Bohmian expert if I've ever seen one) acknowledged that Bohmian Mechanics is contextual. Nonlocal AND contextual. That makes sense to me (although I'm not a Bohmian) because all of the experimental and theoretical evidence points to the idea that QM is both nonlocal AND contextual. There is absolutely nothing that implies otherwise in the entire canon. But clearly, not a logical requirement either.

Give us a specific example of how any local stochastic theory can explain the perfect correlations. And I don't mean by saying X is equivalent to Y, Y is equivalent to Z, so X is equivalent to Z. I mean: How do those entangled photons, previously uncorrelated in any manner whatsoever, demonstrate perfect correlations when a measurement basis is selected midflight and the observers Alice and Bob are far apart?

Admittedly that is not really on you to provide such example; but I cannot extract any concept out of the Barandes paper that implies such is feasible. So if "the wavefunction are not physical objects but solely carry statistical information" as you say, then how do two far distant photons become entangled and then become 100% perfectly correlated? Either there's a nonlocal mechanism at play, or... ???

 

[DrChinese]

I'm not implying these are the same as quantum mechanics, just that Bell-type violations are generic which implies a common cause...

Again, this is arguing both sides of a coin. Bell violations have nothing to do with human behavior whatsoever, and cannot be called "generic" when there is no known similar physical phenomena. If you can demonstrate that no local hidden variable theory can match the predictions of future generally accepted human behavior theory "X", then we'll have something to debate. Because that is what Bell does with QM and local realism.

And whether there are root "causes" or not (for probabilistic behavior) in QM is currently unknown. What is known (as best as can be) is that determinate causes cannot be propagated faster than c. Call that "a causally local formulation of QM" (per Barandes) ? Who cares? Everyone accepts that as far as I can tell, regardless of interpretation. But indeterminate FTL influences ("quantum nonlocality") are clearly within the realm possibility, as hundreds of experiments demonstrate. That's the gold standard.

I actually cannot believe that this is 2024, and anyone is still pushing the idea of a local realistic theory. Barandes should say these words: "Yes, it's nonlocal under the sheets." As I believe I have said previously, I literally have dozens of references for authors claiming "Bell was wrong", there's a hidden assumption, the experiments are tainted, it doesn't work in 10 dimensions or whatever. I had already included Barandes in that list anyway. So *unless* there is a concrete example to discuss/debate as to what I asked in #144, I don't think I have anything further to add of use or interest to anyone in this thread.

 

[Fra]

Again, this is arguing both sides of a coin. Bell violations have nothing to do with human behavior whatsoever,

Yes, just like "observer" in QM has nothing to do with human brains.

The idea is that it however has todo with interacting information processing systems in a more abstract sense. Big difference. Of course, what it REALLY means for an electron to process information about the nucleus is something that needs to be clarified, and noone has yet done it, so this is why I think the explicit examples that you would like to see to be convinced are still not published anywhere. So its fair to be sceptical.

But I think there indeed is a generic phenomena, that exists in certain self-organising complex systems. And self-organisation naturally happens non-trivially when the parts process and act upon information about other parts.

I just watched one of Barandes clips, and I just noticed that the assumption that I find wrong in bells ansatz, and that i called the equiparition assumption, is what he calles "markov divisibility" assumption here.. but its the same thing, and it¨s indeed what prevents the interference patterns; i totally agree with that up to that point.



My only issue with Barandes, is that the big challenge is to see how to construct the transition matrixes that would define the stochastic processes, and I think there is not one stochastic process but many interacting ones... these are not addressed i think in his paper, and this could be what revoulutionize our understanding once we get to understand that more. To leave the marices for some manual fine tuning by physicists is not a good idea. But the way see this, this will be nothing like a simple classical objective stochastic theory, so I think Dr Chineese doesn't need to worry about wether we are in 2024. I think what will come out of this will both clarify some things with quantum mechanics, but at the price of introducing even other proably worse trouble.

/Fredrik

 

[iste]

That is quite similar to the Bohmian concepts where there are ongoing influences ("pilot waves"). But for everything to work out, there must be contextuality. And that requires FTL influences - and I mean explicit ones - to make sense. There can be no hiding behind the mask of a local stochastic interpretation.

I am pretty sure this interpretation evades the criticisms against Bohmian mechanics because it doesn't explicitly write particles into the theoretical machinery and have their trajectories directly determined by a pilot wave or something like that. There are therefore no ongoing influences. It does not strictly describe the behavior of a single particle moving through space, but the statistical behavior if you repeat the scenario a large number of times. And it is fully contextual and non-local by normal quantum mechanics standards. I still don't think you need faster than light influences for contextuality and non-locality.

I still think the idea that Bell violations just follow from incompatibility and/or the absence of joint distributions as a formal relation is sound. I think the fact that Barandes can get non-local correlations from a generalized stochastic system is testament to that, because by its very nature, this implies you don't need other deeper underlying mechanisms to get non-local correlations other than a certain kind of stochastic system with violated Markov properties. Which is strange, because that is in some ways a very un-specific demand for a system. It doesn't seem to be a physical one particularly, in the same way that the equivalence/relationship between Bell violations and absent joint probabilities doesn't seem particularly physical in the sense of depending on whatever physical laws or possibilities that constrain how the world works (e.g. like speed of light).

I still find it plausible that even considering the following:

"...its configuration is always randomly changing..." Because that directly conflicts with the idea that you end up with perfect correlations after measurement settings are remotely changed midflight and the entangled particles are distant (considering c) - and have never interacted in any manner.

Bell violations could still hold purely because they are just a consequence of the absence of a joint probability distribution (and the fact we are talking about probability distributions kind of implies that the relationship must be hold in the midst of random behavior anyway). In the Barandes paper, the violated joint probability distribution is signified by the violated Markov property. The relationship could then be formal in the same way that say the sum of deviations from the mean is always 0. It doesn't matter what sample I am using, where I find it, how far apart they are etc, etc., the sum is always zero because its a formal relationship. Or again, if I rotate objects, it doesn't matter the physical instantiation, those rotations do not commute as a formal requirement. I might make a long quote from a paper shortly to try further to elaborate a response on this.

And to re-emphasize, the mid-flight change in settings will not matter for measurement correlations since all that matters are the setting-dependent joint probability distributions at the point of measurement, this context-dependence being the cause of the joint probability distribution violation that causes Bell violations.

Again, this is arguing both sides of a coin. Bell violations have nothing to do with human behavior whatsoever, and cannot be called "generic" when there is no known similar physical phenomena.

Again, the relationship is formal not physical, which I will try to give an attempt at elaboration from a paper shortly.

And I have to emphasize that Barandes' formulation is arbitrarily as close to standard quantum mechanics as you want. It is as non-local as quantum mechanics is. My line, and I think the line of the latest Barandes paper, is just that these non-local correlations are due to interactions which are entirely local.

 

[Fra]

An attempt to add to the conceptual picture I at least "see" behind this.

Unless the association between stochastic processes and information processing was clear, they way they are connected in my view is simple: Scrambling followed by filtering/selection, can be seen as a natural form of spontanous information processing. This is one conceptual way to view a stochastic process, as a simple kind of information processing. And it needs to be "simple" because as Dr Chinese mentioned, we aren't talking about human infomration processing, but about some abstract seeds for it that we can imagine beeing implemented by simple material systems. This is the link as well to contextual stochastic models and agent perspective. They are not in conflict

What makes this different that a global non-contextal stochastic model, is that that a non-contextual mode is by constructing lacking insight into the internal causal mechanism of "internal interactions". And this is intuitively what causes interferences.

From model theoretic perspective, Agent based models has some conceptual advantages over the more typical differential based approach, even though many problems can be cast in both forms - they are not in conflict per see. But trying to understand that nature of interactions and causation maybe be easier on one form.

I have not excellent example for this exact topic, but a general paper on the comparasion of ABM vs PDE in complex systems is here

This is no ultimate argument or explict suggestion, but Im just trying to help spark seeing the possibiities that I see, and from the responses here I can tell, some does not see this at present. Which is a pity as i think this is really exciting.

Learning differential equation models from stochastic agent-based model simulations​

https://arxiv.org/abs/2011.08255

Thus the vision is that there is a duality between any effective theory of standard model, and a correspnding agent-based formulation and the latter would be more intuitive, and add explanatory value to quantum weirdness and unification and connect how effective theories renormalize, and how agent-based models evolve as you scale the agents.

All this I would label as stochastic models as well, but DIFFERENT stochastic models than simplistic brownian motion which is non-contextual.

/Fredrik

 

[iste]

Woops, this ended up happening later than I said. Second post will quote from different paper.

So I will post quotes from some papers (might as well be one paper by the same author) who look at spin correlations just as a direct consequence of probability distributions. As far as I can see, they are just elaborating on what Fine said:

(might as well re-link from earlier)
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.48.291
https://pubs.aip.org/aip/jmp/articl.../Joint-distributions-quantum-correlations-and

Bell violations are equivalent to absences of joint probability distributions and absences are a direct consequence of incompatible observables.

Quotes from papers:

https://www.mdpi.com/1099-4300/24/10/1439
(just from abstract)

"The dependence of the spin correlation on conditional probabilities allows for a clear separation between system state and measurement context; the latter determines how the probability space should be partitioned in calculating the correlation. A probability distribution function ρ(φ) is then proposed, which reproduces the quantum correlation for a pair of single-particle spin projections and is amenable to a simple geometric representation that gives meaning to the variable φ"

https://arxiv.org/abs/2108.07869

"Given that we have found a general probability distribution and an appropriate separation of the probability space that accounts for the positive and negative outcomes contributing to the spin correlation, we now explore a possible geometric explanation for this result. With this purpose in mind, let us take a pair of entangled spins and consider the situation in which the sign of the projection of spin 1 onto a has been determined, say α = +1; for simplicity in the discussion take the +z axis along the direction a, and the x axis perpendicular to it. If the bipartite system is in the singlet state, we know for sure that the projection of spin 2 onto the +z axis would give -1. This means that spin 2 lies in the lower half plane, forming any angle φ such that 0 ≤ φ ≤ π, with the origin of φ along the −x axis and φ increasing counterclockwise. Conversely, if the sign of the projection of spin 1 is α = −1, the second spin lies in the upper half plane, forming any angle φ such that 0 ≤ φ ≤ π, with the origin of φ along the x axis. In both cases, A = −1. (The argument is of course reversible, in the sense that the sign of the projection of spin 2 can be defined first, in which case the angle variable φ refers to spin 1.)

In summary, any series of measurements along parallel directions gives perfect anticorrelation, CQ(a, a) = CQ(b, b) = −1.

Consider now a series of measurements carried out to determine the correlation of the spin projections onto directions (a, b) with the +z axis again along a, and b ≠ a. Take first the case α = +1 for spin 1: when spin 2, lying in the lower half plane, is projected onto the direction b forming an angle θab with the +z axis, A will still be negative for any angle φ such that θab ≤ φ ≤ π, whilst it will become positive for 0 ≤ φ ≤ θab. This gives a concrete meaning to Eq. (31). What is it that determines in each instance the specific value of the (random) variable φ is unknown; we only know its probability distribution."

https://arxiv.org/abs/1908.04225

"It is clear from this discussion that an expression that combines eigenvalues Ak, A′k pertaining to different pairs (a, b), (a, b′) is physically meaningless, as it would entail a mixture of elements pertaining to different subdivisions of the ensemble represented by Ψ0; in other words, it would imply the simultaneous use of two partitionings of the probability space which are incommensurable. Yet the procedure of combining under one formula the eigenvalues that correspond to different pairs of directions is central in the derivation of Bell-type inequalities for the bipartite singlet spin state [6]."

"Translated to the experimental domain, this is equivalent to saying that the spin projections (α, β), (α, β′), a.s.o., belong to different series of experiments. Of course the experimentalist may choose to reset the orientation of the apparatus from b to b′ after the first event, and then back to b after the second one. But eventually, after a large number of measurements, the experimental correlation CE (a, b) will be given by the average value of the projection products (αβ)ab, and CE(a, b′) by the average value of the products (αβ′)ab′ ; the experimentalist does not mix the data from the two series of measurements for the calculation of the average values. If different series of measurements are made, for different pairs of directions (a, b), one should expect the experiment to eventually confirm the functional dependence predicted by quantum mechanics; i. e., CE (a, b) = −a · b."

"Our conclusions, carried out entirely within the quantum formalism, finds a counterpart in the literature in the form of the measurement-dependence or contextuality argument. The assumption of noncontextuality (or so-called contextuality loophole) associated with the Bell and CHSH theorems has been pointed out in different ways; for early works see Refs. [8–10]. More recently, it is raised anew by an increasing number of authors (see e.g. [11–15]), stressing that (1) probabilities belong to experiments and not to objects or events per se, and (2) any probability depends at least in principle on the context, including all detector settings of the experiment [12, 13]. In other words, a hidden-variable model suffers from a contextuality loophole if it pretends to describe different sets of incompatible experiments using a unique probability space and a unique joint probability distribution [12, 14]."

And I think if incompatibility is enough for Bell violations like Fine's theorem implies then we have a cause which is local since incompatibility is confined to observables local to particles. The local incompatibility directly leads to the explicit in the partitioning of probability spaces concerning commuting pairs. The local causes then end up leading to non-local correlations. We don't need communication non-locally because what is required for the Bell violations is the inability to construct a context-invariant joint probability distribution, regardless of whether there is some kind of communication between particles or not. Communication may be a cause of loss of joint probability distribution presumably… but so can measurement-dependent statistics - i.e. contextuality without non-local influences - which is pretty much what is identified as the source in these papers and implied by Fine's.

The question of how particles "know" the measurement setting during the experiment is resolved by the fact that particle configurations are always randomly changing. A particle begins its trajectory at t0 and is measured at t8; we can think of it having probability distributions concerning its configuration at every time point. The final measured outcome at t8 then spontaneously appears at the point of measurement, just as a configuration outcome spontaneously occured at t7 or t6 or t2, etc. At t8, it is now in the local vicinity of the measurement setting it depends on and the context-dependent distributions, which are valid precisely for that time point, are what causes the Bell violation in measurement outcomes.

 

[iste]

Again, this is arguing both sides of a coin. Bell violations have nothing to do with human behavior whatsoever, and cannot be called "generic" when there is no known similar physical phenomena. If you can demonstrate that no local hidden variable theory can match the predictions of future generally accepted human behavior theory "X", then we'll have something to debate. Because that is what Bell does with QM and local realism.

And whether there are root "causes" or not (for probabilistic behavior) in QM is currently unknown. What is known (as best as can be) is that determinate causes cannot be propagated faster than c. Call that "a causally local formulation of QM" (per Barandes) ? Who cares? Everyone accepts that as far as I can tell, regardless of interpretation. But indeterminate FTL influences ("quantum nonlocality") are clearly within the realm possibility, as hundreds of experiments demonstrate. That's the gold standard.

I actually cannot believe that this is 2024, and anyone is still pushing the idea of a local realistic theory. Barandes should say these words: "Yes, it's nonlocal under the sheets." As I believe I have said previously, I literally have dozens of references for authors claiming "Bell was wrong", there's a hidden assumption, the experiments are tainted, it doesn't work in 10 dimensions or whatever. I had already included Barandes in that list anyway. So *unless* there is a concrete example to discuss/debate as to what I asked in #144, I don't think I have anything further to add of use or interest to anyone in this thread.

So this is second post with quotes. I am nit sure that the first post was tagged to you. So just in case, just letting you know there is another post above which quotes from paper specifically about spin correlations.

These authors I will quote are appealing to the exact same line of argument implied by Cetto from previous quotes. But this time they are talking about much more general scenarios so not just quantum. This is because Bell inequality is a special case of the inequalities that Boole discovered in the century prior which, like in Fine's paper, is fundamentally about probability spaces, so that violations occur simply because data points cannot be fit onto a single probability space. Obviously the aim of their argument though is about quantum mechanics. Their example starts properly in the 2nd paragraph of the quote.

https://arxiv.org/abs/0907.0767

"Obviously the inequality of Eq. (3) is non-trivial because based on the fact that the value of all products must be ±1 one could only conclude that: Γ(n) ≥ −3. The nontrivial result has the following reason. Boole included into Eq. (2) a cyclicity: the outcomes of the first two products determine the outcomes in the third product. Because all outcomes can only be ±1 the cyclicity gives rise to Eq. (3). Vorob’ev showed precisely 100 years after Boole’s original work in a very general way that it is always a combinatorial-topological cyclicity that gives rise to non-trivial inequalities for the mathematical abstractions of experimental outcomes. Boole pointed to the fact that Eq. (3) cannot be violated. However, in order to come to that conclusion, the [variables] need, in the first place, to be in a one to one correspondence to Boole’s elements of logic that follow the law “aut A = +1 aut A = −1 tertium non datur”. As discussed in the introduction, eternally valid statements about physical experience such as “aut A = +1 aut A = −1 tertium non datur” can usually not be made when describing the physical world without the use of some coordinates. In the example above these coordinates were the places of birth, the places of examination and the numbering of the exams that were randomly taken. All these coordinates when added need to still allow for a cyclicity in order to make Boole’s in-equality non-trivial. Therefore, if we have a violation of a non-trivial Boole inequality, then we must conclude that we have not achieved a one to one correspondence of our variables to the elementary eternally true logical variables of Boole and that we need further “coordinates” that will then remove the cyclicity. In order to illustrate all this by
a simple example, we consider the following second different statistical investigation of the same disease.

We now let only two doctors, one in Lille and one in Lyon perform the examinations. The doctor in Lille examines randomly all patients of types a and b and the one in Lyon all of type b and c each one patient at a randomly chosen date. Note that in this way, all patients of type b receive two examinations. The doctors are convinced that neither the date of examination nor the location (Lille or Lyon) has any influence and therefore denote the patients only by their place of birth. After a lengthy period of examination they find: Γ = ⟨AaAb⟩ + ⟨AaAc⟩ + ⟨AbAc⟩ = −3.

They further notice that the single outcomes of Aa, Ab and Ac are randomly equal to ±1. This latter fact completely baffles them. How can the single outcomes be entirely random while the products are not random at all and how can a Boole inequality be violated hinting that we are not dealing with a possible experience? After lengthy discussions they conclude that there must be some influence at a distance going on and the outcomes depend on the exams in both Lille and Lyon such that a single outcome manifests itself randomly in one city and that the outcome in the other city is then always of opposite sign. Naturally that way they have removed the Vorob’ev cyclicity and we have only the trivial inequality Eq. (6) to obey.

However, there are also other ways that remove the cyclicity, ways that do not need to take recourse to influences at a distance. For example we can have a time dependence and a city dependence of the illness as follows. On even dates we have Aa = +1 and Ac = −1 in both cities while Ab = +1 in Lille and Ab = −1 in Lyon. On odd days all signs are reversed. Obviously for measurements on random dates we have then the outcome that Aa, Ab and Ac are randomly equal to ±1 while at the same time Γ(n) = −3 and therefore Γ = −3.

We need no deviation from conventional thinking to arrive at this result because now, in order to deal with Boole’s elements of logic, we need to add the coordinates of the cities to obtain: Γ = ⟨A1aA2b⟩ + ⟨A1aA2c⟩ + ⟨A1bA2c⟩ ≥ −3. And the inequality is of the trivial kind because the cyclicity is removed.

The date index does not matter for the products since both signs are reversed leaving the products unchanged. However, in actual fact, also this index might have to be included and could be a reason to remove the cyclicity, e.g. Γ = ⟨A1a(d1)A2b(d1)⟩ + ⟨A1a(d2)A2c(d2)⟩ + ⟨A1b(d3)A2c(d3)⟩ ≥ −3, where we now have included the fact that the exams of pairs are performed at different dates d1, d2, d3."

"The mistake here is that Bell and followers insist from the start that the same element of reality occurs for the three different experiments with three different setting pairs. This assumption implies the existence of the combinatorial-topological cyclicity that in turn implies the validity of a non-trivial inequality but has no physical basis. Why should the elements of reality not all be different?"

In the quantum case, the difference in elements is due to incompatibility / non-commutativity with regard to spin.

Of course the examples would be contrived but they are arguing the same perspective as the other quantum papers. Bell violations follow from the absence of probability distributions. There are no additional conditions saying that, e.g. physically x, y, z must hold too or you need x, y, z to occur for this violation to happen. It's just a formal relationship between probability distributions and the violations. If Fine's theorem hadn't pointed to incompatible observables as the cause, I would probably be more skeptical and think that maybe an absent joint distribution in the Bell scenarios requires non-local interactions. But there is no reason why local incompatibility requires non-local interactions to exist.

You can derive non-commutativity from the non-differentiability / stochastic nature of Feynman paths in the path integral formulation and so getting non-commutativity formally doesn't seem to have anything to do with non-locality either. This is especially relevant to a stochastic interpretation as implied by Barandes' formulation because the realized outcomes that occur on trajectories between two points in Barandes' formulation are just the Feynman paths in the path-integral framework, and carry the same non-differentiable nature because of the randomness of the paths.

 

[physika]

"The idea is that it however has todo with interacting information processing"

"there indeed is a generic phenomena, that exists... ...in self-organizing process... ...and self-organization, naturally happens... ...when the parts process and act upon information about other parts."

As
https://physics.aps.org/articles/v17/s36

 

[DrChinese]

1. So this is second post with quotes. I am nit sure that the first post was tagged to you. So just in case, just letting you know there is another post above which quotes from paper specifically about spin correlations.

2. These authors I will quote... https://arxiv.org/abs/0907.0767

3. We now let only two doctors, one in Lille and one in Lyon perform the examinations...

4. "The mistake here is that Bell and followers insist from the start that the same element of reality occurs for the three different experiments with three different setting pairs. This assumption implies the existence of the combinatorial-topological cyclicity that in turn implies the validity of a non-trivial inequality but has no physical basis. Why should the elements of reality not all be different?"

1. Yes, I saw.


2. I have been following the deRaedt team's work for 15+ years. One of the early members of my list of Bell deniers. I think their work is sufficiently well known amongst the community at large; I reject their conclusions as has the community.


3. As I have said repeatedly, examples such as these have no relevance or analogy to QM. I have given you a simple challenge, one that involves not Bell but EPR. You see: EPR demonstrated that perfect correlations with entangled particles (systems that have interacted in the past) imply QM is incomplete or wrong. Well, back then there had never been an experiment with entanglement. And guess what, Remote Entanglement Swapping had never even been considered in anyone's wildest dreams. So the following challenge is simply a moderns re-creation of EPR. Hopefully this challenge will show any doubters the importance of the experimental results of the past 35 years.

There is a card player named Alice in Lille, and another named Bob in Lyon. Their card decks are completely uncorrelated. They can shuffle or even arrange their decks as they like, as long as there has been no communication or pre-arranged agreement between them. Then a magician named Chris in distant Paris snaps her fingers, and instantly: the Lille and Lyon card decks are perfectly correlated to the following standard. Dale, an observer in Versailles, selects a number from 1 to 52 as N. He phones Lille and Lyon and asks for the color of their Nth card in their respective decks. Amazingly, each of the decks produces the same color card for the Nth card. This trick is repeated as often as desired, with the same results. At no time is there any communication between the principals, other than Dale getting the results from Alice and Bob. How is this trick performed without breaking the rules?

This is the analogy that MUST be explained by anyone pretending there is local realism. This is NOT reproducing Bell, and has no assumptions regarding any of the red herrings presented by hand waving Bell Deniers respected scientific authors/teams with alternative opinions. This is simply reproducing the 1935 EPR elements of reality in 2024 form. "If, without in any way disturbing a system, we can predict with certainty (i.e., with probability equal to unity) the value of a physical quantity, then there exists an element of physical reality corresponding lo this physical quantity " With Remote Entanglement Swapping from Independent Sources, the elements of reality have never been in a common backward light cone.

Care to explain this modern version using specifics? This is as simple as it gets before eventalking about Bell. You start with completely uncorrelated photons, and end up with completely correlated photons. I've already referenced multiple experimental papers by Zeilinger teams and others, let me know if you need those.


4. As mentioned, Bell not involved.

 

[iste]

Remote Entanglement Swapping

This is not a big concern to me. Barandes' formulation can account for entanglement swapping. The relationship between generalized stochastic systems and quantum mechanics is bi-directional so you don't even have to construct a stochastic version of entanglement swapping experiments, you can just directly translate the quantum description into a stochastic one and it will retain the same behaviors but with trajectories of realized outcomes.

And Barandes' formulation is centered around violations for total probability for Markov properties. Violations of total probability signify breakdowns of joint probability distributions so the formulation seems to be amenable to the same kind of analysis of its own non-local phenomena in terms of Fine's theorem, absent joint probability distributions etc.

How is this trick performed without breaking the rules?

This is the analogy that MUST be explained by anyone pretending there is local realism.

Well presumably an example like this is assuming non-contextuality. From the perspective I have been arguing, and Fine's theorem, certain kinds of context-dependent statistics at each of the respective cities may be enough to preclude a joint probability distribution. Bell violations may just follow from that.

I think we just aren't going to agree because we have fundamentally different assumptions. You want a kind of explicit, detailed local-causal chain of events connecting the distant events; but from my perspective, this just doesn't exist. For me, it isn't necessary if you just look at the Bell violations as equivalent to joint probability violations - a formal relationship that just looks very, very strange and unintuitive but is not fundamentally about local chains of events, or indeed any kind of causal directionality. The equivalence seems well-established: e.g. another modern reaffirmation of Fine's theorem below.

https://arxiv.org/abs/1102.0264

"We show that contextuality, and non-locality as a special case, correspond exactly to obstructions to the existence of global sections [which defines a distribution on all measurement outcomes]."

Definite particle properties are then compatible with this if you allow an ensemble interpretation of the statistics and stochastic behavior in their trajectories.

So I don't understand the need for the kind of explanation you want when the presence of incompatible observables seems enough. Until one person changes their assumption then we just cannot agree, I guess.

 

[DrChinese]

1. Well presumably an example like this is assuming non-contextuality.

I think we just aren't going to agree because we have fundamentally different assumptions. You want a kind of explicit, detailed local-causal chain of events connecting the distant events; but from my perspective, this just doesn't exist.

2. Definite particle properties are then compatible with this if you allow an ensemble interpretation of the statistics and stochastic behavior in their trajectories.

So I don't understand the need for the kind of explanation you want when the presence of incompatible observables seems enough. Until one person changes their assumption then we just cannot agree, I guess.

1. Again, there are no assumptions at all, and certainly nothing whatsoever about contextuality (or not). It is simply a prediction of QM that any interpretation must to explain. This is 1935 thinking, pre-Bell, just nonlocal EPR "elements of reality" that are demonstrated experimentally by modern experiments with independent and distant sources.

There is no "detailed local-causal chain of events connecting the distant events; but from my perspective, this just doesn't exist" because... there IS quantum nonlocality. Not sure why you keep saying there are "local interactions" without saying there are nonlocal influences. Either there is nonlocality in Barandes' ideas (and yours) - or there is not. Which?

2. There are no ensemble statistics or "incompatible observables" here. Perfect correlations from distant systems that have never interacted eliminate all that.

While I don't agree we have different assumptions, I do agree that you refuse to address this simple challenge - that is already demonstrated experimentally as I have indicated.

Penn and Teller can wave their hands and magic happens, but this is actual science. How do those previously uncorrelated and distant decks of cards become correlated without a nonlocal influence? Anyone?

 

[martinbn]

How do those previously uncorrelated and distant decks of cards become correlated without a nonlocal influence? Anyone?

I don't think your challenge is fair. What you describe cannot be done with QM either.

 

[Fra]

Before I say anyone I am sensing again the old confusion what nonlocality means. We know that what Bell means, it's essentially the violation of the inequality; this KIND of "nonlocality" is of course not a problem per see and does not imply FTL-violations.

1. Again, there are no assumptions at all, and certainly nothing whatsoever about contextuality (or not). It is simply a prediction of QM that any interpretation must to explain. This is 1935 thinking, pre-Bell, just nonlocal EPR "elements of reality" that are demonstrated experimentally by modern experiments with independent and distant sources.

There is no "detailed local-causal chain of events connecting the distant events; but from my perspective, this just doesn't exist" because... there IS quantum nonlocality. Not sure why you keep saying there are "local interactions" without saying there are nonlocal influences. Either there is nonlocality in Barandes' ideas (and yours) - or there is not. Which?

2. There are no ensemble statistics or "incompatible observables" here. Perfect correlations from distant systems that have never interacted eliminate all that.

While I don't agree we have different assumptions, I do agree that you refuse to address this simple challenge - that is already demonstrated experimentally as I have indicated.

Penn and Teller can wave their hands and magic happens, but this is actual science. How do those previously uncorrelated and distant decks of cards become correlated without a nonlocal influence? Anyone?

My personal take on the "remote entanglement swapping" that you often hightlight is that it is just a combination of two independently correlated systems/pairs, that are post-filtered (the SWAP) thereby you achieve the entanglement between two partifcles that "never communicated". But this was debated in other threads, and I lost interest in the details, but I think you never got convinced to see it like this. Without the information from the SWAP even, you can never conclude the entanglement.

For me there core mystery in entanglement swapping is that same as in original entanglement, it's just a more complex example, that may rather obscure than clarify.

/Fredrik

 

[RUTA]

I don't think your challenge is fair. What you describe cannot be done with QM either.

Yes, more information than merely "snapping his fingers" is needed in order to produce an accurate analogy :-)

In quantum mechanics, the state providing the distribution of outcomes among the detectors contains information about the entire spatiotemporal context of the experiment given a particular source and its detectors (usually just implied, but necessary for understanding what the state is describing). I'm not talking about hidden variables, what I'm saying applies to the quantum state even if it is assumed to be complete. You have to know what the symbols in the mathematical representation of the state mean in terms of detectors for a source and their locations and/or orientations in space, so as to make physical sense of the distribution of outcomes for the experiment.

For example, the singlet state says when the detector settings are the same Alice and Bob will get opposite outcomes. So, you need to know what a detector and its settings are, what an outcome means for that detector, and you need a source that produces those outcomes for those detectors.

Anyway, we need all that information in the analogy so we can answer the challenge.

 

[Fra]

Anyway, we need all that information in the analogy so we can answer the challenge.

I think Dr Chinese meant that it's up to those that suggest that we can understand the logic of "quantum entanglement" outside of physics, such as in human interations - to complete the example. (Reasonable i admit!)

I think it may be possible but it takes some creativity to construct an example involving decks.

But I think an example must involve some kind of betting in an expectation game is required. I havent felt motivated to just that but i presume those researching game theory in relation to quantum strategies in economy might have some exsmpmes?

I googled and found this recent paper...

Bell correlations outside physics​

https://www.nature.com/articles/s41598-023-31441-x

/Fredrik

 

[DrChinese]

1. I don't think your challenge is fair. What you describe cannot be done with QM either.

2. Yes, more information than merely "snapping his fingers" is needed in order to produce an accurate analogy :-)

In quantum mechanics, the state providing the distribution of outcomes among the detectors contains information about the entire spatiotemporal context of the experiment given a particular source and its detectors (usually just implied, but necessary for understanding what the state is describing). I'm not talking about hidden variables, what I'm saying applies to the quantum state even if it is assumed to be complete.

3. My personal take on the "remote entanglement swapping" that you often hightlight is that it is just a combination of two independently correlated systems/pairs, that are post-filtered (the SWAP) thereby you achieve the entanglement between two partifcles that "never communicated".

1. It can be done and has been done. Here is the reference:

High-fidelity entanglement swapping with fully independent sources

Initially entangled Photons 1 and 2 (state ψ-) originate from the Slave, initially entangled Photons 3 and 4 (also state ψ-) originate from the Master. There is no initial correlation between Photons 1 and 4, which are created distant from each other (in terms of light speed). After a remote Bell State Measurement (BSM) on Photons 2 and 3, Photons 1 and 4 become perfectly correlated in one of 4 possible (and random) Bell states, only 2 of which can be identified (ψ+ or ψ-). The experiment only uses 4 fold relative coincidences within the specified time window, all others are ignored.

2. Sure, I simplified for example purposes. Although fleshing it out changes little for the challenge itself. And I agree with you statement about "entire spatiotemporal context of the experiment".

3. How do you post-filter something "here" and cause it to correlate something "there"? The final correlated pair has never been in the vicinity of each other, and are also separated from the swapping mechanism (BSM).

---

Original challenge: There is a card player named Alice in Lille, and another named Bob in Lyon. Their card decks are completely uncorrelated. They can shuffle or even arrange their decks as they like, as long as there has been no communication or pre-arranged agreement between them. Then a magician named Chris in distant Paris snaps her fingers, and instantly: the Lille and Lyon card decks are perfectly correlated to the following standard. Dale, an observer in Versailles, selects a number from 1 to 52 as N. He phones Lille and Lyon and asks for the color of their Nth card in their respective decks. Amazingly, each of the decks produces the same color card for the Nth card. This trick is repeated as often as desired, with the same results. At no time is there any communication between the principals, other than Dale getting the results from Alice and Bob. How is this trick performed without breaking the rules?

So to satisfy on some of the details of the analogy, let's clarify as follows:

1. In my original analogy: there were only 2 decks; but @RUTA wants more than a finger snap from the magician in Paris. So we'll need 4 decks to be more true to the referenced experiment. We'll label the card decks 1/2/3/4 to match the Photons in the experiment. Each set of 4 Decks represents a single 4 fold coincidence (i.e. one useful trial) in the experiment. Obviously, this is an analogy and every element of the actual experiment cannot be modeled.

2. To keep the explanation simple, we'll treat the initial entanglement (between 1 & 2, and between 3 & 4) as being state ψ+, meaning that there is initially correlation rather than anti-correlation. So Alice in Lille shuffles a Deck (Deck 1) and then created an identical one (Deck 2). Bob in Lyon does the same to end up with 2 identical decks, Deck 3 and 4. No communication or pre-agreement is allowed between Alice and Bob as to their Deck preparation. These are independently prepared, as in the actual experiment.

3. Alice sends her Deck 2 to magician Chris in Paris, and Bob sends his Deck 3 to Paris as well.

4. Here the analogy breaks down a little, as there is no classical manner to model the experimental Bell State Measurement producing ψ+ or ψ- outcomes. But we will allow as follows: The final correlated state of Decks 1 & 4 can be correlated ψ+ or anti-correlated ψ-, just as in the experiment. The magician's snap of the fingers will then be: the magician Chris will select a card randomly (no pre-arrangements allowed!) from each of the decks (Deck 2 from Lille, Deck 3 from Lyon). If the cards are the same color, then the Decks remaining in Lille and Lyon are correlated. If they are different colors, they are anti-correlated.

5. Dale, the observer in Versailles, need to get a call from Chris to learn whether Chris sees cards indicating Alice and Bob's decks (1 and 4) are correlated, or anti-correlated. So in the end: Dale picks N (from 1 to 52), Alice and Bob check their respective Nth cards and phone those results to Dale, and Dale already knows whether they will be correlated or anti-correlated. So once Dale receives the call with the result (red or black) from Alice, Dale can predict with certainty the result Bob will report.

---

What's the point of all of this? We have now realized the original 1935 version of EPR elements of reality: "If, without in any way disturbing a system, we can predict with certainty (i.e., with probability equal to unity) the value of a physical quantity, then there exists an element of physical reality corresponding to this physical quantity." This result was anticipated pre-Bell based on general expectations on entanglement as known back then.

But we did so in our analogy (and in the realized referenced experiment) with an important twist they could never have envisioned: The random correlations/anti-correlations were created nonlocally, without any type of coordination or initial correlation of any type between Alice and Bob ("independent sources") - in distant cities in the analogy, but outside backward light cones in the experiment.

So, here we have no assumptions related to Bell at all. There is no assumption of contextuality or non-contextuality, nothing about counterfactuals, etc. Elements of reality are created remotely in systems that have never interacted (unlike in the original).

My question demand for any Interpretation denying any form of nonlocality is: Specifically, in terms of this card deck example: how are Bob's random outcomes able to be predicted with certainty when all of Alice's and Chris' actions are far away, too far away to be explained by influences at speeds of c or less?

Of course there is no problem if there exist FTL components within the interpretation; or if the interpretation makes provision for including the future context as part of the overall mechanism (as some "acausal" interpretations do). We don't understand how standard/minimal/Copenhagen/orthodox/textbook QM accounts for this, but the generally accepted explanation is that there is *something* called "quantum nonlocality" that fits the bill. Quantum nonlocality being, in the analogy, the magician Chris' finger snaps.

 

[iste]

Again, there are no assumptions at all, and certainly nothing whatsoever about contextuality (or not).

Alright, Yes I see. I guess I was implying that contextuality is all you need.

Not sure why you keep saying there are "local interactions" without saying there are nonlocal influences

I just think that non-local correlations do not need to be causal and therefore they do not need to be influences in a causal sense.

There are no ensemble statistics or "incompatible observables" here. Perfect correlations from distant systems that have never interacted eliminate all that.

Yes, I know there are no ensemble statistics in the example; it was just a little add-on that with these factors you can have definite particle properties. I don't think ensemble statistics don't prevent perfect correlations at all if Bell violations can be derived from the absence of joint probability distributions.

And incompatibility is responsible for Bell violations so I don't really understand how asking someone to solve some thought experiment without them says too much.

While I don't agree we have different assumptions, I do agree that you refuse to address this simple challenge - that is already demonstrated experimentally as I have indicated.

Because the challenge has been addressed by Fine's theorem probabilistically.

 

[martinbn]

@DrChinese what is the 52 analogus to? It seems that you want to match 52 cards here and 52 there for a given trial, but with photones there are no 52 values that you get for a given measurement.

 

[DrChinese]

@DrChinese what is the 52 analogus to? It seems that you want to match 52 cards here and 52 there for a given trial, but with photons there are no 52 values that you get for a given measurement.

It's an analogy, nothing magic about 52 per se other than the simple visual of a randomly arranged deck of cards. Half are red, half black, all mixed up. So the analogy with the color is like a photon's H> or V> polarization (or however you want to represent it - +/- or 1/-1 etc) at some angle setting to be measured by both Alice and Bob. And the 52? How many different angles are there in a full circle? Or in a quarter circle? Technically you could say: infinite. But for our purposes, 52 different angles yielding a binary result should suffice.

There is no way to arrange such a deck of cards so that it would reproduce the usual cos^2(theta) statistics, any more than you could pre-assign values for 52 different polarization measurement outcomes on a photon. But we don't need that to hold, as we are looking only for the EPR perfect correlations ("elements of reality").

I just think that non-local correlations do not need to be causal and therefore they do not need to be influences in a causal sense.

Who said anything about causal influences? The outcomes are random as far as anyone knows. Certainly not a requirement of the challenge for some A to cause B, anyway you can make it work if it gets the necessary result. But "something" must be influencing "something", whether it is mutual, directionless, or displays a preferred direction in time.

This is experimentally demonstrated, proving the elements of reality appear. People hate the terms "action at a distance" and "FTL", so "quantum nonlocality" it is.

 

[martinbn]

But you cannot measure one photon at 52 angles. You can do it for just one angle. And QM, at least standard text book QM, says that the observables for the different angles do not commute. You cannot have values for all of them like a deck of cards. The better analogy would be to fix the axis and have just one card per person. If you need more angles you need more trials.

 

[RUTA]

@DrChinese, that's one convoluted experiment! But, it does beautifully portray the spatiotemporally global, "all-at-once" nature of the outcome distributions and correlations due to the original two Bell states and all the measurement locations and settings in spacetime. If the Bell states are complete, then there are no card decks, just a single card at each measurement outcome. In that case, you can imagine choosing a setting for each measurement then placing a card at each measurement outcome so that all the outcomes are consistent with the Bell states and measurement settings used. Of course in doing so, you're operating 'outside' spacetime, so good luck telling that story via causal mechanisms within spacetime :-)

 

[DrChinese]

@DrChinese, that's one convoluted experiment! But, it does beautifully portray the spatiotemporally global, "all-at-once" nature of the outcome distributions and correlations due to the original two Bell states and all the measurement locations and settings in spacetime. If the Bell states are complete, then there are no card decks, just a single card at each measurement outcome. In that case, you can imagine choosing a setting for each measurement then placing a card at each measurement outcome so that all the outcomes are consistent with the Bell states and measurement settings used. Of course in doing so, you're operating 'outside' spacetime, so good luck telling that story via causal mechanisms within spacetime :-)

But you cannot measure one photon at 52 angles. You can do it for just one angle. And QM, at least standard text book QM, says that the observables for the different angles do not commute. You cannot have values for all of them like a deck of cards. The better analogy would be to fix the axis and have just one card per person. If you need more angles you need more trials.

Agreed completely for both of you, didn't mean to imply that the cards not selected must have specific values (although I see why that comes across). EPR explicitly admits that only one "element of reality" can be demonstrated at a time. They also say in a local hidden variable scenario (a more complete specification of the system) all counterfactual possibilities would be assumed to exist. Whether they do or don't, that's part of the challenge: your trick must still explain how to get perfect correlations.

So there is to be just one angle setting (the Nth card) selected and tested per trial. There is no assumption here other than Alice and Bob can produce a result for that one common setting - no other cards need be looked at. To match experiment, Alice and Bob must get matching colors each trial. But they don't know which card (angle) will be selected in advance (unless there is a mechanism that allows this)! Yes, I know that there are 52 cards in my deck example, but that's merely an artifact of trying to map a quantum example into something we can picture mentally. That being that there is a choice of many measurement bases, whether it be 52 (corresponding to a card deck), 360 (corresponding to number of degrees in a circle), or 8 (the number of pieces in my apple pie).

---

@RUTA It seems convoluted because I cannot express myself more concisely, sorry 'bout that. The whole thing about cities in France (Lille, Lyon, etc) stretches back to the Doctor/Patient analogy using those cities - which is a terrible analogy because it does not relate in any relevant way to quantum mechanical experiments. This example is built around perfect correlations a la EPR.

So this really is exactly as described in 1935 EPR with these 2 differences: a) we are looking at a spin basis* rather than the position/momentum basis; b) most important: the 2 systems have never interacted, nor is there sufficient time for any 3rd signal to be transmitted to them both (once they are entangled) indicating how they are to be measured (or how to otherwise synchronize).

For someone who holds the viewpoint of Relational BlockWorld (RBW): This challenge is successfully met, because the mechanism of RBW ("the trick") would include as relevant elements the full quantum context, including the future elements. Being "acausal", there is no issue connecting the dots between seemingly distant points in spacetime, even from future to past. Because those spacetime points will actually all be connected by "acausal lines of influence" (not sure what you might call them) that all respect c. Exactly as the experiment is constructed using photons, which of course move at c anyway. I would call this "local" but not "locally causal" **. And I would call it fully contextual, because there are no counterfactuals to consider.

So for anyone asking about a good example of an interpretation that is local and non-realistic (i.e. explicit contextuality, and no hidden variables): here it is!


*This change was introduced around the time of Bohm (circa 1950).

** "Causal" meaning here: a) Causes are distinguished from effects; and b) causes must precede effects. "Acausal" or "not causal" denying one or both of a) and b).

 

[martinbn]

@DrChinese I still don't understand the challenge. Alice shuffles a deck and creates an identical one. Bob does the same completely independently. They send one of their decks to Chris. He picks out a number, say 10, looks at the 10th card of each deck. Their colour may match or not. If they do, we check cards number 10 in the decks at Alice's and Bob's. They match of course. But this is trivial and classical. QM can do a lot more than that. Of course I realize that this is not what you meant by your challenge, this isn't a challenge at all. So what did you mean?

 

[Fra]

It is trivial becase we explained the correlation but haven't specified a interaction at say Alice which involves her deck. To just "look at the deck" is trivial, it's hard to get some interferences out of that.

I think the challenge is find an "interaction" involving the deck states that we can understand (maybe via via some rationally randomly betting IGUS/agent) and that shows outcomes that differs depending on wether the entangled decks sent to Chris are kept SECRET(=isolated) or not, from the gaming enviromment, and other "players" in the implicit environment.

My hunch is I think such an example should be possible, but I don't have one. If we find on, that may convince Dr Chinese to take the analogies to "social interactions" and other context where claims to demonstrated bell inequality more serioulsy. One problem with that however, is that do make such an example we need to construct the correspondence of the "hamiltonian" for such agent interactions. And I fear those who do not like this could still object that these constructiions are ambigous, as such hamiltionians would necessarily be only "effective" as one can not make a first principle modelling of two interacting agents as it would be a chaotical dynamical system.

/Fredrik

 

[DrChinese]

@DrChinese I still don't understand the challenge. Alice shuffles a deck and creates an identical one. Bob does the same completely independently. They send one of their decks to Chris. He picks out a number, say 10, looks at the 10th card of each deck. Their colour may match or not. If they do, we check cards number 10 in the decks at Alice's and Bob's. They match of course. But this is trivial and classical. QM can do a lot more than that. Of course I realize that this is not what you meant by your challenge, this isn't a challenge at all. So what did you mean?

No, Chris does a different thing with the copy decks 2 & 3, simply picking a card from each deck - this is supposed to be the analog of performing a Bell State Measurement (BSM). That is a separate action and is not directly correlated to the polarization of the Alice & Bell angle settings. It is indirectly related because it indicates whether Alice and Bob's Nth cards is going to be perfectly correlated or anti-correlated. What I had said about this was:

"The magician's snap of the fingers will then be: the magician Chris will select a card randomly (no pre-arrangements allowed!) from each of the decks (Deck 2 from Lille, Deck 3 from Lyon). If the cards are the same color, then the Decks remaining in Lille and Lyon are correlated. If they are different colors, they are anti-correlated. ... Dale, the observer in Versailles, need to get a call from Chris to learn whether Chris sees cards indicating Alice and Bob's decks (1 and 4) are correlated, or anti-correlated. So in the end: Dale picks N (from 1 to 52), Alice and Bob check their respective Nth cards and phone those results to Dale, and Dale already knows whether they will be correlated or anti-correlated. So once Dale receives the call with the result (red or black) from Alice, Dale can predict with certainty the result Bob will report."

What we are trying to show if the practical difficulties of hypothesizing a local mechanism that has nonlocal appearance in the Remote Entanglement Swapping scenario. I don't think any local causal mechanism can accomplish this. Where local means: influences (random or not) not to exceed c; and causal means: the identified cause must precede an identified effect.

1. It is trivial because we explained the correlation but haven't specified a interaction at say Alice which involves her deck.

2. I think the challenge is find an "interaction" involving the deck states that we can understand (maybe via via some rationally randomly betting IGUS/agent) and that shows outcomes that differs depending on wether the entangled decks sent to Chris are kept SECRET(=isolated) or not, from the gaming enviromment, and other "players" in the implicit environment.

My hunch is I think such an example should be possible, but I don't have one. If we find on, that may convince Dr Chinese to take the analogies to "social interactions" and other context where claims to demonstrated bell inequality more serioulsy.

1. See above, there is no trivial explanation. I just didn't explain well. The 1 and 4 decks are initially uncorrelated, therefore the Nth card in each of these decks will not be perfectly correlated in Lille and Lyon. Chris does something in Paris and then they are correlated (anticorrelated) for the Nth card, regardless of the selection of N.

2. In actual experiments, the deck copies sent to "Paris" have a Bell State Measurement performed on them. That creates an entangled state for Decks 1 & 4 (Photons 1 & 4). The BSM (on 2 & 3) does not reveal any information about the color of the card (polarization) for the Nth card (angle setting) for 1 & 4. Chris in Paris doesn't even know what N is. To that extent, I guess you could say there is a "secret".

3. Again, the original deRaedt et al "Doctors in Lille and Lyon" social example (I am long familiar with that) in no way represents an analogy to quantum mechanics. The only purpose of that contrived example is to show that a "Bell-like" classical limit can appear to be violated in a specific classical scenario. This isn't a debate about whether such an example is a disproof of some underlying assumption in Bell (which it isn't). Here, nowhere are we referencing Bell inequalities!

Instead, Bell built on EPR's perfect correlations. Many an anti-Bell idea has been tripped up by forgetting that perfect correlations are a requirement too, as well as explaining violation of Bell inequalities. But one thing none of EPR or Bell lived long enough to learn of the existence of remote swapping (teleportation first proposed circa 1993, Rosen died 1995). Had they lived to see these Report Entanglement Swapping experiments realized, they would have certainly realized that the original EPR concept ("elements of reality") would now require nonlocal influences to work out.

 

[martinbn]

No, Chris does a different thing with the copy decks 2 & 3, simply picking a card from each deck - this is supposed to be the analog of performing a Bell State Measurement (BSM). That is a separate action and is not directly correlated to the polarization of the Alice & Bell angle settings. It is indirectly related because it indicates whether Alice and Bob's Nth cards is going to be perfectly correlated or anti-correlated. What I had said about this was:

"The magician's snap of the fingers will then be: the magician Chris will select a card randomly (no pre-arrangements allowed!) from each of the decks (Deck 2 from Lille, Deck 3 from Lyon). If the cards are the same color, then the Decks remaining in Lille and Lyon are correlated. If they are different colors, they are anti-correlated. ... Dale, the observer in Versailles, need to get a call from Chris to learn whether Chris sees cards indicating Alice and Bob's decks (1 and 4) are correlated, or anti-correlated. So in the end: Dale picks N (from 1 to 52), Alice and Bob check their respective Nth cards and phone those results to Dale, and Dale already knows whether they will be correlated or anti-correlated. So once Dale receives the call with the result (red or black) from Alice, Dale can predict with certainty the result Bob will report."

What we are trying to show if the practical difficulties of hypothesizing a local mechanism that has nonlocal appearance in the Remote Entanglement Swapping scenario. I don't think any local causal mechanism can accomplish this. Where local means: influences (random or not) not to exceed c; and causal means: the identified cause must precede an identified effect.

1. See above, there is no trivial explanation. I just didn't explain well. The 1 and 4 decks are initially uncorrelated, therefore the Nth card in each of these decks will not be perfectly correlated in Lille and Lyon. Chris does something in Paris and then they are correlated (anticorrelated) for the Nth card, regardless of the selection of N.

2. In actual experiments, the deck copies sent to "Paris" have a Bell State Measurement performed on them. That creates an entangled state for Decks 1 & 4 (Photons 1 & 4). The BSM (on 2 & 3) does not reveal any information about the color of the card (polarization) for the Nth card (angle setting) for 1 & 4. Chris in Paris doesn't even know what N is. To that extent, I guess you could say there is a "secret".

3. Again, the original deRaedt et al "Doctors in Lille and Lyon" social example (I am long familiar with that) in no way represents an analogy to quantum mechanics. The only purpose of that contrived example is to show that a "Bell-like" classical limit can appear to be violated in a specific classical scenario. This isn't a debate about whether such an example is a disproof of some underlying assumption in Bell (which it isn't). Here, nowhere are we referencing Bell inequalities!

Instead, Bell built on EPR's perfect correlations. Many an anti-Bell idea has been tripped up by forgetting that perfect correlations are a requirement too, as well as explaining violation of Bell inequalities. But one thing none of EPR or Bell lived long enough to learn of the existence of remote swapping (teleportation first proposed circa 1993, Rosen died 1995). Had they lived to see these Report Entanglement Swapping experiments realized, they would have certainly realized that the original EPR concept ("elements of reality") would now require nonlocal influences to work out.

But i already objected to this and you agreed! The 52 cards represent 52 angles of measurment. On a given trial with photons 1, 2, 3 and 4 you can measure only for one angle for wach photon, not 52. You are asking for the two decks, 1 and 4, to become correlated, all 52 cards. There is nothing like that in the entaglement swaping case.

 

[DrChinese]

But i already objected to this and you agreed! The 52 cards represent 52 angles of measurment. On a given trial with photons 1, 2, 3 and 4 you can measure only for one angle for wach photon, not 52. You are asking for the two decks, 1 and 4, to become correlated, all 52 cards. There is nothing like that in the entaglement swaping case.

I agreed that there is no assumption that the entire decks must be correlated. Just the one 1 & 4 pair being tested (the Nth card), which were not previously correlated. But they must be correlated for each and every trial. How is the trick accomplished?

The issue here is that with EPR: They specified there was correlation because the system had previously interacted. While the details of the interaction itself were not known, presumably there was some conservation rule or other mechanism at work. But with the new "updated" version of EPR: There was no interaction. So what trick causes the swap to correlate distant systems if they have never interacted?

Obviously, this nonlocal twist could never have been foreseen by Einstein, Bohr, or even Bohm or Bell. They all passed away prior to the discovery of nonlocal swapping.

 

[martinbn]

I agreed that there is no assumption that the entire decks must be correlated. Just the one 1 & 4 pair being tested (the Nth card), which were not previously correlated. But they must be correlated for each and every trial. How is the trick accomplished?

But this is classical! He picks the Nth cards from decks 2 and 3. If they match, which they will with 50% chance, the Nth cards of deck 1 and 4 will too. This is trivial. And happens on every trial.

The issue here is that with EPR: They specified there was correlation because the system had previously interacted. While the details of the interaction itself were not known, presumably there was some conservation rule or other mechanism at work. But with the new "updated" version of EPR: There was no interaction. So what trick causes the swap to correlate distant systems if they have never interacted?

Well i explained it. There is nothing magical with the cards. There is something quite different with entangelment, but entanglement swapping doesn't add anithing new to it.

Obviously, this nonlocal twist could never have been foreseen by Einstein, Bohr, or even Bohm or Bell. They all passed away prior to the discovery of nonlocal swapping.

I am not familiar with the history and when it was all realized first, but that doesn't matter for this discussion.

 

[DrChinese]

But this is classical! He picks the Nth cards from decks 2 and 3. If they match, which they will with 50% chance, the Nth cards of deck 1 and 4 will too. This is trivial. And happens on every trial.

I’ll repeat: Chris in Paris is performing the card trick equivalent of a swap. She has no idea what N is, that information is not communicated to Paris. There is thus no opportunity for Chris to look at the Nth cards in the first place. That’s why the trick cannot be accomplished as you imagine.

Instead, Chris picks one card randomly from each of the 2 decks and communicates “match” or “no match” as to color. This is as close to the swap analogy as we can get. In an actual Bell State Measurement, there is a measurement of polarization as one component of the overall BSM. But it is at an angle fully independent of the angle settings of Alice and Bob.

 

[martinbn]

I’ll repeat: Chris in Paris is performing the card trick equivalent of a swap. She has no idea what N is, that information is not communicated to Paris. There is thus no opportunity for Chris to look at the Nth cards in the first place. That’s why the trick cannot be accomplished as you imagine.

Instead, Chris picks one card randomly from each of the 2 decks and communicates “match” or “no match” as to color. This is as close to the swap analogy as we can get. In an actual Bell State Measurement, there is a measurement of polarization as one component of the overall BSM. But it is at an angle fully independent of the angle settings of Alice and Bob.

Ok, but then you need to look at the corresponding cards in 1 and 4. Say Chris picked the 5th card in 2 and the 10th card in 3. Then the 5th card in 1 and the 10th in 4 will be correlated.

If this is not what you mean then run the experiment with specific outcomes, so that I can see what the challenge is.

Now I suspect that your desired analogy is not analogous to the swap at all. Then the challenge is not fair. But I will wait to see the example of an experimental run to see what exactly you ask.

 

[DrChinese]

1. Ok, but then you need to look at the corresponding cards in 1 and 4. Say Chris picked the 5th card in 2 and the 10th card in 3. Then the 5th card in 1 and the 10th in 4 will be correlated.

2. If this is not what you mean then run the experiment with specific outcomes, so that I can see what the challenge is.

1. Chris has no communication from anyone about what N is, i.e. selecting the Nth card. That's because in a Bell State Measurement (BSM) on photons (card decks) 2 & 3, the angle settings are held constant and do not change from trial to trial. The information gained from the BSM indicates a ψ+ (colors of 2 & 3 match in the analogy) or ψ- (2 & 3 don't match in the analogy).

The real BSM actually operates like this, just so you can see that there is no useful information gained as to the specific outcomes that will be seen by Alice (photon 1) and Bob (photon 4):

a) The 2 & 3 photons must overlap in time (i.e. be indistinguishable) at a beam splitter (BS), and they can either come out the same ports or different ports of the BS. Whether you have ψ+ or ψ-: one will always be vertically polarized |V> and the other will always be horizontally polarized |H>. They are therefore always orthogonal, and in principle should never directly interact.

b) Each output port of the single BS has a polarizing beam splitter (PBS) and 2 detectors at their output ports - one for the |V> and one for the |H>. So 1 BS, 2 PBSs and 4 detectors in total for the BSM. The angle orientation of the 2 PBSs are the same, but bears no specific relationship to anything happening with Alice's and Bob's settings. Again, this is held fixed from trial to trial.

c) If both detectors click on one side (the same output port of the BS), the resulting Bell state is ψ+. If they show up on different sides of the BS, the resulting Bell state is ψ-. ψ+ means the Alice and Bob outcomes will correlate perfectly at any same angle setting selected for them. ψ- means the Alice and Bob outcomes will anti-correlate perfectly at any same angle setting. In other words: since the polarization outcomes of 2 & 3 are always |HV> or |VH> (indistinguishable), their polarization makes no difference to learning whether there will be correlation or anti-correlation for Alice and Bob. It is whether the 2 & 3 photons appear on the same side - or different sides - of the BS output ports that determines that.

Now, this entire BSM process cannot be mapped directly to any card decks. So I am merely modeling it as if Chris in Paris essentially picks 2 random cards and therefore gets a random outcome - which we then associate with ψ+ or ψ-. And a random outcome is precisely what the actual BSM produces!

2. Sure.

a) Alice (decks 1 & 2, these are to be alike) and Bob (decks 3 & 4, also to be alike) shuffle (or otherwise arrange) their decks independently.

b) They send decks 2 & 3 to Chris, who does "something" which produces a + or - result, without knowing anything about how Dale will select N (the Nth card from each of decks 1 & 4). Let's say Chris see different colors (Red from deck 2, Black from deck 3) and calls that a "-" (which would be ψ-). Note again, this is simply a random outcome of whatever Chris does, just like the outcome of a real BSM is random.

c) Chris sends her "-" result to Dale. Dale then selects N=37 (which neither Alice nor Bob knew in advance). He gets the color of Alice's 37th card. It is Red. Dale immediately know that Bob's 37th card will be Black, because Chris' "-" results means anti-correlated on Alice/Bob colors.

d) More trials might look like this:
Chris "+", Dale N=12, Alice=Red, Bob=Red (as Dale predicted).
Chris "+", Dale N=49, Alice=Black, Bob=Black (as Dale predicted).
Chris "-", Dale N=49, Alice=Black, Bob=Red (as Dale predicted).
Chris "+", Dale N=20, Alice=Black, Bob=Black (as Dale predicted).
Chris "-", Dale N=12, Alice=Red, Bob=Black (as Dale predicted).
Chris "-", Dale N=32, Alice=Black, Bob=Red (as Dale predicted).

How can Dale make good predictions when Alice in Lille and Bob in Lyon don't know what each other are doing; Chris does not know N (which is selected by remote Dale) and is merely reporting a random "+" or "-"?

---

Each of Dale's successful predictions are the EPR definition of an "element of reality". Alice's measurement could not have affected Bob's outcome if local causality holds - they are distant. In the original EPR, they believed that such an element of reality occurred because the Alice and Bob particles had interacted in the past, and there would be conservation rules at play. Therefore the result of any measurements on Alice and Bob must be predetermined (at least that's what their logic told them).

In my "modern" version of EPR: There is an element of reality in each trial, just as in the original. But... the Alice and Bob particles had NEVER interacted in the past. So there is no conservation rules at play to explain the observed correlation/anti-correlation. That is replaced by Chris' Bell State Measurement, which is the "cause" of the swap. Chris is too far away from all of the others for the outcome of Chris' BSM to affect the outcomes of Alice and Bob's measurement, if local causality* holds.

• Bohmian explanation: There is explicitly nonlocality, so locality** fails.
• Relational Blockworld ( @RUTA hopefully you agree here) : Reality is "acausal", so causality* fails.
• Orthodox QM: Quantum nonlocality mechanism is not specified in the theory, but locality** and/or causality* fails and the theoretical predictions are upheld.

*Causality meaning: there is a) an identifiable cause which is separate from its effect; and b) the cause must precede the effect.
** Locality meaning: no physical influence can propagate or otherwise connect space-like separated particles or events.

 

[martinbn]

@DrChinese It seems that you want what Chris does to be a projection of the 2 and 3 onto a Bell state. Everything else is irrelevant. The nonlocality and entanglement swap are not needed at all. Your challenge is simply to create a Bell state using cards. It is also inconsistant because 1&2 and 3&4 at the begining are not in Bell states.