How valid is the indivisible interpretation of quantum mechanics?

[javisot]

What concern do you have with entanglement and this correspondence?

Barandés' interpretation does not offer the local explanation that we would so much like for any form of entanglement. (Sarcasm mode on)

 

[pines-demon]

Barandés' interpretation does not offer the local explanation that we would so much like for any form of entanglement. (Sarcasm mode on)

More like Barandes interpretation does not want to define its properties in terms of usual entanglement terminology. I still don’t know if it super deterministic, hidden variables non local or something else (à la MWI). He wants to define it under Barandes made-up terms, by which nonlocality does not even exist to begin with.

 

[Fra]

I think at the heart of Barandes proposal and insight (and I fully agree with him even if there are missing pieces of his puzzle) is that Bell's definition and use of locality is not useful to understand natures causal interconnections! It is rather a reciepe for confusion to insist analysing things in those terms. This is why he introduces something he think is better - causal locality.

Of course to those that don't like Barandes ideas, this sounds like a way to just "reinvent established terms" and cause more confusion. But I think that is not the case. I think he he serious that analysing things using bells definitions is a problem, because the tools and paradigms we use to map things out, may cause artifacts, that are not artifacts of nature but from us trying to find explanations with the wrong ansatz, so that the missing pieces noone denies, ends up in the most akward positions.

/Fredrik

 

[iste]

Where does he claim the probabilities for trajectories exist? As far as I recall he has said that trajectories exists and is real, and probabilities for transitions - not trajectorires exist.

This is not a contradiction or problem for me though, because the ontology of the trajectories traced out by a subsystems configuration, is itself contextual to the subsystem itself (for me this is conceptually analogous to beeing contextual to an inside observer). The probability OTOH, is contextualy to the the WHOLE system (or conceptually analogougs to an external obseerver). If objectives probabilities of trajectories existed, that would as far as I see risk making it the precise type of HV theory that are ruled out by Bells theoreem.

/Fredrik

I might try to find exactly where in videos but pretty sure Barandes talks about the towers of probabilities for a stochastic process and that we don't have epistemic access to them and Albert I think tries to get Barandes to say they are not specified by the theory.

 

[Morbert]

I might try to find exactly where in videos but pretty sure Barandes talks about the towers of probabilities for a stochastic process and that we don't have epistemic access to them and Albert I think tries to get Barandes to say they are not specified by the theory.

I would like to see your source for this because it would be very surprising to me.

 

[gentzen]

I might try to find exactly where in videos but pretty sure Barandes talks about the towers of probabilities for a stochastic process and that we don't have epistemic access to them and Albert I think tries to get Barandes to say they are not specified by the theory.

I would like to see your source for this because it would be very surprising to me.

1:11:36

So the second point is there's some more structure. There's modal structure. There's probabilistic structure in this theory and there has to be because we need probabilities to sew things together. Here I'm very much motivated by my older work on the modal interpretations which suffered from a lack of the structure and from the Everett question mark theory which lacked the structure. A sort of connective tissue connecting one time to another that lets these wild fluctuations happen. We don't like that. Okay. So here's the second point. What I'm saying is that each system we want to consider whether it's open or closed in addition to having configurations forms a stochastic process. Now a stochastic process is a fairly old idea. Um stochastic processes go back the better part of a century. What is a stochastic process? In general, a stochastic process I can give you the mathematical definition, but I'm not going to do that. Won't be interesting to people. One way to think about a stochastic process is it's some kind of variable maybe representing the configuration of something. And this variable changes probabilistically with time. And this model comes with modal structure. Modal structure meaning like structure beyond just physical like ontological facts at locations in space like other structures. Modal structures include things like probabilities and laws and so forth. There's more modal structure here. These stochcastic processes come with probability distributions over multiple times. Right? So the the model comes with a probability distribution that the variable is some value x at a given time. It comes with a probability distribution that the variable is X at a certain time and Y at some other time. It comes with the probability that the variable is X at a given time, Y at a given time, Z at another time, and so on and so on. There's just this this tower of so-called multi-time joint probabilities just, you know, where where the system is. That's a lot of additional structure. Now often simplifications are made when stochcastic models are used in practice. We assume that a lot of that extra structure is somehow trivial or ignorable and we get a very simple kind of stochastic process called a Markov process. The characteristic feature of a Markov process is that you just have to know what's going on at one time and then you can you have probabilities that tell you what happened later and the ...

 

[gentzen]

I would like to see your source for this because it would be very surprising to me.

You are right to be surprised. It doesn't happen often that people understand criticisms and adapt accordingly:

The discussion did not just "feel" more substantive. What I have watched so far (~1h 43min) was factually a lot more substantive than many previous discussion of Barandes, not just the one with Maudlin.

What is different is that Barandes understood various critisisms of his approach in the meantime, understood that there were implicit assumptions that he didn't spell out, and now tries to explain those to Albert.

Oh no another 2h and half podcast on Barandes. Does he discuss entanglement? I don't want to listen it just to hear the same arguments introduced.

More like Barandes interpretation does not want to define its properties in terms of usual entanglement terminology. I still don’t know if it super deterministic, hidden variables non local or something else (à la MWI).

Looks like you are really finished with Barandes. But that podcast actually really clarifies what Barandes had in mind, but did not spell out.
In the end, he might land a bit too close to Fra/Fredrik, because he doesn't necessarily get laws of physics from his approach, and is actually happy with that.

 

[Morbert]

1:11:36

it seems like if you were to somehow take all of those multi-time joint probabilities to be laws, it would be a huge amount of information you'd have to specify. In principle, an infinite amount of information. And we don't want laws that are infinitely complicated.

The problem with these joint probabilities, denoting observed relative frequencies the omniscient observer happened to observe, is they are not reproducible. The observer could collect a new sample of trajectories, and the observed relative frequencies don't have to be the same. They don't have to be regular.
[https://www.physicsforums.com/threa...opic-theory-of-causality.1080105/post-7305662]

In particular, probabilities assigned to whole trajectories, as constructed from higher-order conditional probabilities in the sense of (10), are then left unspecified as well. The higher-order conditional probabilities of an indivisible stochastic process could, in principle, vary contingently from one set of instantiations or runs of the process to another.

What I was hoping for was these towers of probabilities giving rise to inaccessible probabilities for trajectories that are nevertheless regular or lawlike. I fully accept that there are in principle probabilities for trajectories.

 

[iste]

I would like to see your source for this because it would be very surprising to me.

On that same video there are statements of the sort all through about 1:17 to 1:46, and quite a clear concise summary from about 1:42 - 1:46. Barandes says these trajecyory probabilities exist but we have no epistemic access to them.

 

[Morbert]

On that same video there are statements of the sort all through about 1:17 to 1:46, and quite a clear concise summary from about 1:42 - 1:46. Barandes says these trajecyory probabilities exist but we have no epistemic access to them.

Would you agree that these are the same probabilities he talks about in 2.2 In his correspondence paper where he says "In particular, probabilities assigned to whole trajectories, as constructed from higher-order conditional probabilities in the sense of (10), are then left unspecified as well."

 

[iste]

What I was hoping for was these towers of probabilities giving rise to inaccessible probabilities for trajectories that are nevertheless regular or lawlike

Well, they could be lawlike, Barandes isn't specifying whether they are lawlike or not because he doesn't have any access to them.

Would you agree that these are the same probabilities he talks about in 2.2 In his correspondence paper where he says "In particular, probabilities assigned to whole trajectories, as constructed from higher-order conditional probabilities in the sense of (10), are then left unspecified as well."

Would you agree that these are the same probabilities he talks about in 2.2 In his correspondence paper where he says "In particular, probabilities assigned to whole trajectories, as constructed from higher-order conditional probabilities in the sense of (10), are then left unspecified as well."

Yes, agreed.

 

[Fra]

I might try to find exactly where in videos but pretty sure Barandes talks about the towers of probabilities for a stochastic process and that we don't have epistemic access to them and Albert I think tries to get Barandes to say they are not specified by the theory.

In the end, he might land a bit too close to Fra/Fredrik, because he doesn't necessarily get laws of physics from his approach, and is actually happy with that.

What I was hoping for was these towers of probabilities giving rise to inaccessible probabilities for trajectories that are nevertheless regular or lawlike. I fully accept that there are in principle probabilities for trajectories.

On that same video there are statements of the sort all through about 1:17 to 1:46, and quite a clear concise summary from about 1:42 - 1:46. Barandes says these trajecyory probabilities exist but we have no epistemic access to them.

Well, they could be lawlike, Barandes isn't specifying whether they are lawlike or not because he doesn't have any access to them.

Would you agree that these are the same probabilities he talks about in 2.2 In his correspondence paper where he says "In particular, probabilities assigned to whole trajectories, as constructed from higher-order conditional probabilities in the sense of (10), are then left unspecified as well."

I now listened to the key part where Albert keeps asking what is the fundamental law but isn't satisfied with Barandes saying "it's just stochastic", while Barandes struggles with understanding the category of answer Albert wants, which seem to reason from the traditional equation/system paradigm with initial/boundary conditions. As Barandes points out, the "law" is probably not best cast that way. But Albert don't seem convinced.

I see how the reaons is not convincing from Barandes presentation alone; to someone with a deep stance in the traditional paradigm. I follow Barandes logic, but its because I am already roughly on the same page to start with, I didn't need to be convinced. And my own arguments would necessarily go beyond the discussion and likely cause more confusion.

** In QM standard hilbert picture.This is system dynamics, and DYNAMICAL law encoded in the hamiltonian (or alternatively the equations of motion)

** In stochastic picture.There exists no traditional dynamical law. "Time evolution" is just a stochastic process in configuration space. No time evolution law is needed. But the process is constrained by Gamma,

Although different, I think gamma loosely encode what the hamiltonian encode.

So instead of asking why this hamiltonian, how to understand the internal structure of the hamiltonian, Barandes says its "just a stochastic processs", there is no fundamental "dynamical law". There is no NEED for more. But instead we need to ask, why the particular stochastic constraint Gamma; and what the particular configuration space. No of that is innocent. I think Barandes does not speak much about this because the same "fine tuning" exists i hilbert picture. So this is not a NEW problem, and its not the problem his correspondence is set out to solve, at least not at this stage.

For ME this is a key point, and i think conceptually contemplating emergent gamma is easier than emergent hamiltonian (although it is a different discussion) But I think Albert's objection is simply that he feels there must still be a dynamical law behind a stochastic model (just like there is in statistical mechanics). This is perhaps why he says to Barandes "you cant just say its a stochastic system". But I would say that to really appreciate the stochastic picture, a paradigm shift of thinking about physical theory is needed, as it boils down to the question, exactly WHY is the stochastic picutre better? And what is the difference to the simlpe statistical mechanics and entropic dynamics?

About the higher order probabilities, that one CAN contemplate for general stochastic processes (but that aren't needed in Barandes picture), are IMHO not relevant for normative probabilities. They makes no sense from my perspective at least (as normative in an agent picture), the history should be implicit in Gamma itself. I think the first order transitiions are sufficient, because they answer what i think is the only relevant question. P(future|now) - but, there is more information in here than the state of NOW, in the general case I think P itself evolves. But this is not true for a "stable quantum system". So this discussion gets us to the fringe of things.
Because the previous state history would refer to the systems own path, and from inference perspective, it is intutitive to me that these have no role to play because the system should have learn what cna be learned from its own histroy, or something is wrong. They may be allowed, but I see them as serving no purpose. This is just my hunch about this. I'm guessing there is a reason why Barandes leaves this murky stuff for future work. As it in itself, has no role to play for the stochastic quantum correspondnece as i see it.

/Fredrik

 

[Morbert]

Although different, I think gamma loosely encode what the hamiltonian encode.

Γ indeed encodes the dynamics of the theory. It just doesn't select a unique probability measure on the space of trajectories. It's easy to argue that this is peculiar. It's much harder to argue that this is a deficiency.

 

[Fra]

It's easy to argue that this is peculiar. It's much harder to argue that this is a deficiency.

I would rather say that to me, that having "probability of histories" out of the way is not peculiar, it is a good sign! Not by a remote chance a defiency.

This is because that is imo a "non-physical" context. Which Barandes calls out of empirical reach. But for me that is not a practical issue, it really means its non-physical. And really have no place.

(My confidence/logic behind comes from the interacting subsustems picuture in agent based modelling paradigm; which is stochastic at its heart but has more stuff than Barandes speaks about)

/Fredrik