I A new realistic stochastic interpretation of Quantum Mechanics

[Fra]

Agents don't have some  essential role in Bayesian causal modelling, which is what Barandes is using. As I said in the rest of my post, you can deflate the role of an agent in a way that is like any other event or any other "data generating process".

You mean like the specific computers have no essential role in computing? Any computer can be deflated to a turing machine?

/Fredrik

 

[gentzen]

Agents don't have some  essential role in Bayesian causal modelling, which is what Barandes is using. As I said in the rest of my post, you can deflate the role of an agent in a way that is like any other event or any other "data generating process".

It is not so easy. Even so Bayesian networks can be defined without reference to subjective probabilities, Bayesianism, or interventionist statistical methods, their name and most important use cases originated in work by Judea Pearl on causal modelling. And Barandes does give a reference to a book by J. Pearl:

... opens up an important connection with the literature on Bayesian networks [61], which provide a much more amenable foundation for a non-interventionist causal account.

[61] J. Pearl. Causality: Models, Reasoning and Inference. Cambridge University Press, 2009.

But Pearl's work on Bayesian networks is much older. I found for example:
Geiger, D., Verma, T. S. & Pearl, J. (1990). Identifying independence in Bayesian networks. Networks 20, 507-34.

In my post above, I gave a quote from Pearl showing that he accepts the importance of interventions. Here is a quote from wikipedia confirming their importance:

Experimental verification of causal mechanisms is possible using experimental methods. The main motivation behind an experiment is to hold other experimental variables constant while purposefully manipulating the variable of interest. If the experiment produces statistically significant effects as a result of only the treatment variable being manipulated, there is grounds to believe that a causal effect can be assigned to the treatment variable, assuming that other standards for experimental design have been met.

Also note that I responded especially to your proposal of how to "deflate the role of an agent":

Causality may seem easier from an agent perspective; but then, I don't think we need agents. Furthermore, I think the idea of an agent is a construct that can always be deflated - like how a human's agency is nothing above what a brain can do, which in itself is just a physical system. Agentive causation is then in some sense completely illusory.

The problem with this proposal is that one tries to get rid of agents in order to increase the objectivity and predictive power of a model. But your proposal doesn't get rid of the problematic part of agents which decrease predictive power. You just introduce a whole bunch of degrees of freedom which we can neither measure nor control.

Barandes' approach has no agents or observers and I don't see why it should need them

Maybe let us separate QM and Barandes' approach from why we have a hard time to get rid of agents and their interventions.

and I don't think anyone here has given any kind of tangible reason that the role of observers or agents should be made more important and special.

I don't want to make them more important, rather the opposite. But in order to do this, I have to start with acknowledging their presence in our current models and scientific methods. Then I can start pointing out why they are problematic, and replace them by less problematic concepts. For example in SR and GR, the notion of coordinate system already gets rid of the interventionist part of agents. (And going to reference system might further abstract away the arbitrariness of coordinates. Or use covariance to cope with their arbitrariness.)

Reducing from "many agents" down to "one single agent" could also be progress towards getting rid of them.

 

[iste]

Maybe let us separate QM and Barandes' approach from why we have a hard time to get rid of agents and their interventions.

Well this is the central issue. Because as I said in my previous post, there is nothing wrong with agents or interventions in science, and people use them all time as concepts. When I say there is nothing essential about them, I mean there is nothing special that distinguishes them from anything else that can be plugged into statistics. We can talk about observers in Barandes model but there is nothing special about them above this deflationary sense - an observer is just another physical system behaving in the same way as any other. Anything quoted from Pearl about agents and interventions is not going to be interesting. What is interesting is when people elevate the observers and have them intrinsically essential, something deflated in the Barandes framework - Barandes' observers are uninteresting; and without collapse, they are even less so. In conventional QM there would be a sense that if a measurement wasn't made, an outcome wouldn't exist and so there is an interventionist notion in the specific sense that purportedly a measurement that collapses an entangled state causes an outcome very far away to come into existence when it wouldn't have otherwise. Tbh, its not quite clear to me why Barandes thinks that Bell's theorem relies on this type of intervention. Its not obvious to me at least.

 

[iste]

You mean like the specific computers have no essential role in computing? Any computer can be deflated to a turing machine?

/Fredrik

I mean an agent isn't anything.above its physical components. There are no special laws for agents.

 

[Fra]

I mean an agent isn't anything.above its physical components. There are no special laws for agents.

I think everyone that as agent like interpretations agrees the agent is simply a physical system, that has smaller components, just as a piece of matter yes.

But the difference between calling something "an agent", rather than "a physical system", is one of perspective. And this difference (depending on what you think) may or may not improve insight.

The physical system view, is an external perspective; that requires a context. Typically the macroscopic environment; and the causality is on "system dynamics" level. One might argue however (like Barandes does) if this is really causation, or just a timeless picture.

The agent view, is an intrinsic perspective; the agent IS the context. And the causality is understood on agent processing and action level. Ie. the causality is implemented in how the local parts interact with other local parts. And the system level dynamics is emergent, as a collective.

IF course, when the agent is microstructure and agent population is stable and large enough to form a continuum, these two perspectives must be dual or consitent to each other. So they are not in contradiction, but they have different advantages.

For example one can argue that the high-energy limit; where one often gets problematic finetuning and breakdown of explanatory value and predictive power in the system dynamics view; corresponds to the low-complexity limit of agents; where agents get as simple as they can get. Here there should not be any fine tuning. The problem is instead to show that the emergent "high complexity" limit wich correspons to the so called low energy limit in traditional terms match current models.

Had string theory not had the fine tuning issues (here i associate the string ~ the primordal agent), it could have been such an excellent example, and it would have either given the correct low energy limit, and have been right, or have given the wrong limite, and thus have been wrong. I am not into string theory, i just mention this as stringtheory is well known, and part of it is ambitious, and it illustrated the principle that yes, an agent can be a physical system. But that in itself is not the problem nor the point. It is the perspective.

If this wasn't convincing i should stop anyway. I am definitely not favouring a theory of physics with an preferred observer. It's not all all the value of the agent picture. It's more subtle.

/Fredrik

 

[gentzen]

What is interesting is when people elevate the observers and have them intrinsically essential, something deflated in the Barandes framework - Barandes' observers are uninteresting; and without collapse, they are even less so. In conventional QM there would be a sense that if a measurement wasn't made, an outcome wouldn't exist and so there is an interventionist notion in the specific sense that purportedly a measurement that collapses an entangled state causes an outcome very far away to come into existence when it wouldn't have otherwise.

Thanks for your answer.
Let me clarify that embracing agents even more is a task for people like Chris Fuchs or Fra/Frederik, not for Barandes or you. The trouble is that as long as they don't do their work and instead are happy with an open ended "interpretational program" carrying on unfinished forever, even "experienced" researchers like Barandes risk to get stuck.

Let me try to illustrate why. There are situations where the observed system doesn't seem to be altered by the observation:

Are you really sure that it is intuitive? Let's say "we" (i.e. our observatories and telescopes) look at Proxima Centauri, [...]

In fact, thinking about it now, my guess is that our observations of this system didn't actually alter it. But not because it is macroscopic or far away, but because we didn't prepare it (not even the tiniest part of it). And I guess the same is true for observing a decaying radioactive nucleus. But the difference here is that we could have prepared it (even so we rarely do it, if ever).

For Barandes or you, the analysis of those situations is intrinsically more difficult, because observation never alters the observed system in your picture, at least not "after deflation". Therefore, the task to analyse those situations (and determine whether the observation in those specific situations really doesn't alter the observed system) seems to be best handled by people like Chris Fuchs or Fra/Frederik. If people like me or you come to the conclusion that the observed system is not altered, it simply carries less weight than if the same conclusion would be reached by Chris Fuchs or another QBist.

 

[Fra]

There are many details in this discussion, I promised to stop but just wanted to add a comment to this

but because we didn't prepare it (not even the tiniest part of it). And I guess the same is true for observing a decaying radioactive nucleus. But the difference here is that we could have prepared it (even so we rarely do it, if ever).

I guess the implicit question here is: Is there a correspondence to "preparation" of initial state from the agent perspective?

IMO the act of "preparation" is indistinguishable from the act of "reaction". It is conceptually the very same thing. It's just at different extremes of the scale of control.

At one extreme, the control is so strong, that we can repeat the experiment for fast phenomena to the point where we always find a timeless statistical law. It's probably guaranteed; this then deduces future state from the prepared initial state. But this is artifical, and happens only in human labs.

At the OTHER extreme, the control is minimal, and there confidence is the similarly inferred regularities are so low, that initial state to the future state is effectively a guided random walk - (or stochastic process guided by something, something like Baranders transition matrixes in a subjective bayesian interpretation).

Every action, every step, is a preparation for the future. But with low control, which is why one often thinkgs of this as a game or decisions under intrinsically incomplete information. This is the natural version. But the human experiment, is a limiting case and can still be understood in this paradigm; where the "agent" goes from subatomic to the whole macroscopic enviromemt.

That is exactly the issue and issue with the "newtonian paradigm/schema" as well. The inferences we make from taking the limit; are then applied to non-limit scenarios, and this is the cosmological fallacy as Smolin called it.

This is why I view QM as it stands as a limiting case of something unknown. There is nothing wrong with the limiting case. The problem is just that it describes the fictional limit only.

/Fredrik

 

[pines-demon]

Again more videos that I will try to summarize whenever I get to watch them. Here is one with Barandes talking with Scott Aaronson:



I also have not been able to read on the new "microscopic theory of causality" of Barandes.

 

[gentzen]

Again more videos that I will try to summarize whenever I get to watch them. Here is one with Barandes talking with Scott Aaronson:



I also have not been able to read on the new "microscopic theory of causality" of Barandes.

I have watched it now. Maybe I will watch (parts of) it again. Scott is great. He seems to have studied both Jacob's constructions and papers, as well as many of the publicly available reactions (including at least some posts from this thread). He is not dismissive, but gives his honest opinion and detailed feedback. Jacob himself also nicely clarifies where he is coming from, and also clarifies his "position" regarding some of the publicly available reactions.

 

[pines-demon]

Ok, I watched the Aaronson–Barandes talk, thought some parts I watched at twice the speed so I might have missed some specific wordings.

The good:

• It is an amazing conversation to listen. This would forever be my go-to example of what a conversation of interpretations of quantum mechanics should be. Very respectful and very skeptical from both sides.
• Good metaphors on how to explain the issues with interpretations of quantum mechanics, I liked: Library of Babel, Stone Soup and problems of democracy.
• Aaronson clearly understand where Barandes reformulation stands and why it is lacking some ontology.
• Barandes is always deligthful to hear, he really knows his stuff and can show you where an argument is wrong.
• Barandes clarifies that his reformulation is an interpretation.
• Barandes also asserts that indivisible processes are to quantum mechanics, what Hamiltonian/Lagrangian mechanics is to classical mechanics.
• Aaronson gives good recommendations to Barandes on how he can become more convincing.

The bad:

• The podcast is long so it would have been better to come up with a more precise plan of attack.
• Too much discussion on many-world interpretation. Neither Aaronson or Barandes adhere to it so why bother. However it is a good discussion if you want to learn what is wrong with it.

The ugly:

• Scott Aaronson is the advocate of quantum information, why not ask Barandes to explain a single qubit? I was really hoping for that. I also hope Barandes releases that simple calculation draft sooner.
• No talk on entanglement. For me all the interpretational issue rest on explaining entanglement. As said from the previous talk, it all falls down on how Barandes explains entanglement in his "microscopic theory of causality".

If you have not seen anything by Barandes you can start with that last video and you'll get a good idea of where things are at. If you have listened to previous talks there is nothing new aside from better analogies.

 

[Fra]

Thanks for the link! A long talk but i will try to get around to check it out!

I also have not been able to read on the new "microscopic theory of causality" of Barandes.

As I didn't read the paper yet, do you perhpas relate to this?

"The laws of this unistochastic process take the form not of differentiale quations, but of directed conditional probabilities, which have along history of admitting an interpretation as encoding causal relationships. From this perspective, quantum theory could be understood as a theory of microphysical causation par excellence."
-- https://arxiv.org/html/2402.16935v1

This sounds conceptually very similar to the constrast between system dynamics and agent based models. Because the point of that is also precisely the same, that the causal nature is best understood NOT at system level, but at the part-2-part (agent action) level; it's here the explanation of aggregate system level phenomena lies in this idea. Of course, with the caution, the "agent perspective", or agents actions, can be formulated as a kind of conditional probabilities, especially if you take the fictional external view, and views several agents from another perspective, then I think barandes perspective is even better. And it's a first step. Ie conditional upon the agents own best capabilities. This perspective is not explicit in Baranders work, but the tangent is interesting enough.

So in baranders view the causal understanding lies at the bayesian conditional probability level
I consider this as perhaps a simplified case of general agent perspective; simplified in the sense that one takes an "external perspective" of agents, and assume them to have a sort of hidden but real internal states, that explains their conditional probabilities. And this is fine as lone as one ignores the inferential requirements implixit in the "external perspectifve". And ignoring that IS I tink fine, if we ONLY wants to reinterpret QM, but when one tries to add gravity, i think this can't be ignored and things need to get more complex.

I will comment more as I listened to the other video

/Fredrik

 

[pines-demon]

Thanks for the link! A long talk but i will try to get around to check it out!

Again nice talk to hear, but nothing fundamentally new.

As I didn't read the paper yet, do you perhpas relate to this?

"The laws of this unistochastic process take the form not of differentiale quations, but of directed conditional probabilities, which have along history of admitting an interpretation as encoding causal relationships. From this perspective, quantum theory could be understood as a theory of microphysical causation par excellence."
-- https://arxiv.org/html/2402.16935v1

Yes that's the paper. I do not get what it says or your agent based model. I still need to find time for it.

 

[gentzen]

Yes that's the paper. I do not get what it says or your agent based model. I still need to find time for it.

Wait, you mean you only read the first two papers, and were already skeptical about Barandes' approach? For me, it was only that third paper that made me wonder how "I or other researchers" could help Barandes to "get back on track".

 

[pines-demon]

Wait, you mean you only read the first two papers, and were already skeptical about Barandes' approach? For me, it was only that third paper that made me wonder how "I or other researchers" could help Barandes to "get back on track".

I was already skeptical of the whole deal from the beginning. I mean if you are going to give me an interpretation then better be clear. So from step one, I was wondering when was he going to address Bell. From talks and papers I saw that he was consistently dodging the question. For that paper specifically, I watched the talk but saw that he dodged the question by just saying he avoids Reichenbach principle and its alternative was hand-waved. [He even misused the principle as he acknowledged later.] So I did not bother with the paper. It was during the previous talk that I noticed that he really claims there is something there.

 

[Fra]

I mean if you are going to give me an interpretation then better be clear.

I am starting to think there are different meanings for "interpretation".

(I) On one hand, it can mean finding an "ontology" in a given perspective/paradigm. For example, a "hidden variable model" in the normal system dynamics perspective.

(II) But for me "interpretation" can also mean, finding a different perspective/paradigm; something different than system dynamics.

It's easy to see how there can be misunderstandings, because I would say there is not necessasrily a simple way to at all "understand" an interpretation of the second type, if you are looking for a type I interpretation. It simply does not fit into the template of the paradigm.

Once your brain thinks in terms of type (I) paradigm, it is admittdely very hard to see things in any other way, because the very way you construct question and reason are coloured by the paradigm. I think this is what Baranders hints at, when he in the other video suggest that in the traditional system dynamics view, one can certainly question wether there is any true notion of "causality at all"? does it make sense, to say that the past "causes" the future?

Ie. what "kind" of physical causality are we looking for? What forms would a satisfactory answer have?

/Fredrik

 

[pines-demon]

I am starting to think there are different meanings for "interpretation".

(I) On one hand, it can mean finding an "ontology" in a given perspective/paradigm. For example, a "hidden variable model" in the normal system dynamics perspective.

(II) But for me "interpretation" can also mean, finding a different perspective/paradigm; something different than system dynamics.

It's easy to see how there can be misunderstandings, because I would say there is not necessasrily a simple way to at all "understand" an interpretation of the second type, if you are looking for a type I interpretation. It simply does not fit into the template of the paradigm.

I'm interested in (I) but I'll keep (II) in mind.

 

[iste]

[He even misused the principle as he acknowledged later.]

How did he misuse it?

 

[pines-demon]

How did he misuse it?

I already discussed this. He equated Bell local causality with Reichenbach principle saying the two are the same. In one of the last videos, he says that some researcher contacted him to hell him that it was not quite the same.

 

[iste]

I already discussed this. He equated Bell local causality with Reichenbach principle saying the two are the same. In one of the last videos, he says that some researcher contacted him to hell him that it was not quite the same.

Not sure I see what you're saying, he uses the common cause idea in the latest video the same as he always has.

 

[pines-demon]

Not sure I see what you're saying, he uses the common cause idea in the latest video the same as he always has.

I am not sure what you are not getting. In his video talk on Bell's theorem, Barandes clearly says that Bell used Reichenbach principle. In the video with just Curt, part 2, he says that a researcher said to him that Bell did not quite use Reichenbach principle but something slightly different.

 

[iste]

I am not sure what you are not getting. In his video talk on Bell's theorem, Barandes clearly says that Bell used Reichenbach principle. In the video with just Curt, part 2, he says that a researcher said to him that Bell did not quite use Reichenbach principle but something slightly different.

And in the last video with just Curt he very clearly says Bell uses Reichenbachian common cause; so I don't know how to square that up with what you have said about misuse.

 

[Fra]

I am not sure what you are not getting. In his video talk on Bell's theorem, Barandes clearly says that Bell used Reichenbach principle. In the video with just Curt, part 2, he says that a researcher said to him that Bell did not quite use principle but something slightly different.

IMO the problem has always been that bells "conditions" however labels it, lumps several assumptions together. (Realism,some version of locality and some preconception of causatiln that implies the divisibility)

I would say bells condition requires/contains Reichenbach principle, but it is definitely not "the same" because bell adds more, a more naive idea of the nature causation. And i think barandes points out and sees exactly this.

/Fredrik

 

[pines-demon]

And in the last video with just Curt he very clearly says Bell uses Reichenbachian common cause; so I don't know how to square that up with what you have said about misuse.

Watch the part where he talks about Reichenbach factorization (video from February 18, 2025). Later in that section he says:

I've been having an email correspondence with a philosopher of physics, Ioana Luke[?], about this. She's working on a paper where she's looking at all the different formulations of Bell's theorem. And in 1991, he slightly changes the premises a little bit, so he's not relying on exactly the same kind of Reichenbachian factorization, but he still needs all these sort of assumptions about what a good theory of causation could be.

That Bell factorization and Reichenbach principle are not the same has been discussed many times already by other people.

 

[selfsimilar]

Reichenbachian common cause

What is the mechanism for this. otherwise it is trivial, is it not. What I mean is that there is no actual formula for the two particle interaction i.e. Schrodinger equation is not modified.

 

[iste]

What is the mechanism for this. otherwise it is trivial, is it not. What I mean is that there is no actual formula for the two particle interaction i.e. Schrodinger equation is not modified.

Can you elaborate a little more? I'm not sure I understand.

 

[iste]

Watch the part where he talks about Reichenbach factorization (video from February 18, 2025). Later in that section he says:

But this part is so vague compared to the parts immediately before where he is explicitly talking about Bell in terms of Reichenbachian factorization and argues in favor of skepticism. Its just not clear to me that what is being implied in this segmentmakes any significant difference to his thoughts surrounding Bell and Reichenbachian common cause.

That Bell factorization and Reichenbach principle are not the same has been discussed many times already by other people.

In what sense, precisely?

 

[pines-demon]

But this part is so vague compared to the parts immediately before where he is explicitly talking about Bell in terms of Reichenbachian factorization and argues in favor of skepticism. Its just not clear to me that what is being implied in this segmentmakes any significant difference to his thoughts surrounding Bell and Reichenbachian common cause.

Sure but at least he acknowledges that he is taking a bit outside what he knows.

In what sense, precisely?

Bell local causality is more general than Reichenbach principle. You can derive Reichenbach principle by using Bell local causality and asking for a certain type of factorizability (if this factorizability is allowed is a whole other discussion). People that defend Bell, would say that Reichenbach principle is more about causality and does not really matter for microscopic stuff, while Bell local causality is more in line on what is needed here. People that defend Reichenbach principle would say that Bell ask for additional hidden requirements.

I'm not arguing for one or the other, it is just that in his entanglement talk he seemed not to be accurate on Bell's own take. Which led me to believe he was talking outside expertise, he was probably not as off as I thought, but again he failed to clarify (at least for me) what is his microscopic causal theory in that talk.

 

[iste]

Sure but at least he acknowledges that he is taking a bit outside what he knows.

Bell local causality is more general than Reichenbach principle. You can derive Reichenbach principle by using Bell local causality and asking for a certain type of factorizability (if this factorizability is allowed is a whole other discussion). People that defend Bell, would say that Reichenbach principle is more about causality and does not really matter for microscopic stuff, while Bell local causality is more in line on what is needed here. People that defend Reichenbach principle would say that Bell ask for additional hidden requirements.

I'm not arguing for one or the other, it is just that in his entanglement talk he seemed not to be accurate on Bell's own take. Which led me to believe he was talking outside expertise, he was probably not as off as I thought, but again he failed to clarify (at least for me) what is his microscopic causal theory in that talk.

Well, fair enough then!

 

[iste]

I think I have changed my mind on whether contextuality is a conflation (at least in a fallacious way) for Bell inequality and so have made a new understanding of Bell violations for myself.

To clarify, I do think now that all that Bell's inequality does is test contextuality. Bell inequalities don't care about spatial separation, and there are several examples of this; they are just special case I think of a bunch of inequalities in QM that all assess the same thing - contextuality.

But then if contextuality happens to extends to spatial separation, it still needs an explanation of how distant particles or measurements can maintain dependence on each other, when measurement settings can be changed without communication between particles or measurements. I don't think an explanation is impossible.

So I don't think there is an explicit conflation now unless you interpret Bell violations as proving non-local causation; but rather, Bell violation maybe can be made sense of as just a demonstration that no noncontextual model can explain the measurement outcomes (which incidentally happen to be spatially separated). It is just the natural reaction of this finding to assert non-local causation because the contextuality happens to involve spatial separation. That being said, saying that Bell violations does not prove non-local causation does not mean that non-local causation may not be a reasonable conclusion if no one has any other possible explanation. The problem is that extreme constraints on non-local causation is already the consensus in physics so entertaining both non-local causation and idea that nothing can travel faster than speed of light seems almost contradictory or requires undesirable gerrymandering of physics ontology.

I think though also it may be reasonable to think an explanation is possible since if I am not mistaken this small part of quantum is the only major part that really strongly desires non-local causation but maybe thats contestable:

Different indicators of (non)local causation in quantum mechanics?

1. Collapse of non-separable wavefunction induced by measurement where outcomes are spatially distant. Are wavefunctions physically real and "collapse" in a physical event or is the wavefunction just a predictive tool wherein Bayesian conditioning is applicable?

2. Non-signalling across space: do spatially distant measurements alter each other's marginal probabilities, or instead are they compatible? Holds in any empirically adequate quantum formulation.

3. Non-separable states always have a cause in terms of a local interaction. Some might argue this is not the case in entanglement swapping, some argue otherwise (e.g. Mjelva 2024 paper). In Barandes' formalism, a local interaction causes factorization breakdown and this is just maintained due to the indivisibility of the transition matrix.

4. Is there a quantum potential like in Bohmian and Nelson's Markovian stochastic mechanics? Here, factorization breakdown then implies behaviors of one particle depends directly on velocities of spatially distant particles.

5. Do the assumptions used to construct the theory require or imply non-local influences?

6. Bell violations.

7. How does the particle know to behave differently when global configuration changes, e.g. a distant slit opens?

Looking at Bell violations this way - that Bell inequalities do not actually prove non-local causation - it is easier for me to see how a Many Worlder can say their theory is completely local - but imo its just an extremely unsatisfying. If I am not incorrect they would say something like: "these are just all the possible ways things can happen - and they do. I don't really need to explain why; they are just determined to happen that way but there is no reason to invoke non-local causation (especially because there is no collapse)". And obviously, if Bell inequalities don't actually imply non-local causation, then this seems a coherent explanation if you just assume there are these fatalistically pre-determined sets of outcomes that loom really bizarre. It seems similar to retrocausal explanations of Bell violations then.

So I guess my conclusion now is Bell violations just mean contextuality but non-local causation isn't an unreasonable hypothesis if no other explanations can be seen. If all we ever have at our hands is inference to the best explanation then it may be that the only way to truly convince that Bell violation doesn't imply non-locality is to come up with a plausible competing underlying explanation for how exactly these Bell violations happen. Barandes has provided explanations or demonstrations for some parts but not the parts that really need to be explained. At the same time, its difficult to strongly assert some kind of local ontology if you don't have a strong interpretation of why indivisibiity occurs, something which Barandes seems reluctant or unable to give - I do sometimes feel a certain vacuousness when Barandes occasionally says something like: "we can actually explain x now, its just the indivisibility". I do think indivisibility can be made sense of, just that it doesn't seem intuitive unless an explanation for why indivisibility occurs can be given; saying "its just the indivisibility" then doesn't seem to be a statement with much content in the context of a physical theory.

I also think now that maybe Barandes' complaints about Reichenbachian common cause get weaker for me after my new thoughts. I get the point that the local interaction doesn't fit into the Reichenbachian common cause, but obviously you still need a replacement explanation. He does give something like that in regard to how the local interaction expliciltly causes factorization breakdown and that this is maintained by indivisibility; but I understand someone wanting a physical explanation of why the indivisible matrices do this, so maybe its not 100% there, but does go a good way imo.

Apart from that point about the local interaction, all he says seems to amount to the idea (and I am strongly reading between the lines) that there may be an alternative local explanation of Bell violations. But then, saying this isn't convincing until there is a coherent competing explanation given - neither do ideas like Reichenbachian common cause only applying to macroscopic things seems convincng to me at all. When he does try to build a demonstration of locality, it is the non-signalling thing but this isn't explicitly connected in any way to Bell violations, and something like it already coexists with Bell violations normally. From my perspective, it might be actually valid to say that the non-signaling thing is a genuine way of looking at causation while Bell violations only say something about it indirectly, and are actually about something else. But, if Bell violations seem to lead naturally to the idea of non-local causation, then you need to give a competing explanation still, I think - since all we have is inference to the best explanation.

Addition:

There may not be one way of looking at causation, and a theory as opaque as quantum theory may not have a smoking gun as such for showing unambiguously that there is no non-local causation so I guess really it is about plugging all the individual holes adequately. For instance, does Bell violation explanations necessarily coincide with questions about how particles know a slit is open or not? And Dr. Chinese has frequently implied that something like entanglement swapping requires explaining over and above regular entanglement, so its not clear to me that there is a single smoking gun regarding non-local causation. But I do think that, at least from some kinds of interpretations, most of the stuff in the list I gave above can be looked at from a local stance. Personally, I do think there is enough there to believe that quantum theory is locally realistic in some intuitive sense and also violated Bell inequalities, and that there is a plausible explanation of the strange quantum correlations possible.

 

[Jacob Barandes]

I'm incredibly flattered to have found 569(!) posts examining my work here. And in so much depth! I hope you can forgive me, but as a basic rule of time-management and self-preservation, I don't engage in technical discussions on internet forums. So this will be my only post. But why don't you each send me an email letting me know who you are? (iste? Fra? gentzen? pines-demon? others? Sorry for leaving anyone out.) You can find my email address pretty easily. That way maybe I can help answer some of your questions. :) –Jacob

P.S. I get a very large volume of email, so please note that this isn't a general invitation for emails from people not actively contributing to this thread. My apologies!