I A new realistic stochastic interpretation of Quantum Mechanics

[iste]

They insight is rather than expectations is always contextual, or observer dependent.

Sure, but the question is why should there be observer-dependence? Why do interference patterns occur due to adding slits? Neither you or Barandes have offered a deeper explanation of why these things should be considered the norm or non-bizarre in contrast to everyday experience.

and I think acqknowledging the importance of the observers the "stochastic process" is the most obvious solution. But none of this is in his talks.

I think that because the observers are all explicitly included in the model as just sub-systems of the overarching stochastic process there is not really anything else to say about them. It isal laid bare in the formulation and the distinction between observer and non-observer is not special - they are just a kind of physical system which is capable of a precise coupling to whatever states of another system that we find interesting.

 

[Fra]

Sure, but the question is why should there be observer-dependence? Why do interference patterns occur due to adding slits? Neither you or Barandes have offered a deeper explanation of why these things should be considered the norm or non-bizarre in contrast to everyday experience.

You are right of coruse, I see two ways to "answer" this in a big perspective...

1) Via an interpretation where this is preferred

2) To reformulate or reconstruct current theory in a way where the observers have a different role, and show that this reconstructed theory solves many problems; thus this will "prove" the point, just like other reformulations in history proved very viable, such as geometric methods etc. one might as well, why on earth would "geometrization" be better? The answer is I think that someone tried it, and it proved to be very powerful method. I think Baranders point is that again, there may be new formulations that with time will probe powerful and solve old problems

(2) is an open question, and NOone has the answer and published it, and speculations aren't allowed here, so we are left with sniffing around (1), but these arguments does not convinced anyone who is already comitted deeply to anoher interpretation, but it can provide an explanation to those that are not.

Not sure at else I can say that isn't already said in the "mode" of (1). But I had some things i could add, but be back later or tomorrow when i get more time

/Fredrik

 

[gentzen]

You are right of coruse, I see two ways to "answer" this in a big perspective...

1) Via an interpretation where this is preferred

2) To reformulate or reconstruct current theory in a way where the observers have a different role, and show that this reconstructed theory solves many problems; thus this will "prove" the point, just like other reformulations in history proved very viable, such as geometric methods etc. one might as well, why on earth would "geometrization" be better? The answer is I think that someone tried it, and it proved to be very powerful method. I think Baranders point is that again, there may be new formulations that with time will probe powerful and solve old problems

(2) is an open question, and NOone has the answer and published it, and speculations aren't allowed here, so we are left with sniffing around (1), but these arguments does not convinced anyone who is already comitted deeply to anoher interpretation, but it can provide an explanation to those that are not.

Not sure at else I can say that isn't already said in the "mode" of (1). But I had some things i could add, but be back later or tomorrow when i get more time

I am so upset that even you talk of „observers“ now that I have to comment: One unintuitive feature of QM is that you have to interact with a system to observe it. And this interaction alters the system. Classically, I can also alter a system without learning anything about its state prior to the interaction. How does QM change this part? Why can‘t I just forget what I learned during the interaction, if QM should force me to always learn something? Perhaps because my own state was altered nevertheless? (Now you will edit to replace observer by agent, or maybe you already edited. But you and the QBists need to do more to liberate us from this unhealthy focus on observation.)

 

[gentzen]

I would say that if you instead see the nature of causation in the context of interacting and information processing agents(observers) then indivisiblity of the "expected evolution" - which is exactly what the schrödiner equation is, nonthing else - it becomes even almost obvious, that a division, BREAKS the expectation. There is nothing bizarre about this. They insight is rather than expectations is always contextual, or observer dependent.

OK, this was a different post which you edited. But still, one of the "possible actions" I thought about was to write to Chris Fuchs and beg him to exand on the non-observer part of agents, after realizing that Barandes had done good work on QM foundations before he fouled himself into believing that he has a new formulation of QM (similar to Feynman's path integral formulation) or solved the interpretation of the measurement problem.

A much later thought (after watching the recent ToE video with Jacob Barandes and Manolis Kellis) was that Jacob's point that Hilbert spaces give a misleading picture of QM is similar to saying that binary digits give a misleading picture of computers. You might object that our computers today really are based on binary states, and that all attempts to use tenary states instead proved less reliable or less efficient. But the DNA uses quaternary base units, and tenary alternatives can be more efficient or unbiased for survey questions. Tenary also allows less symmetry breaking answers, which is one reason to rather avoid it in surveys. (Faced with the answer options "yes", "no", and "undecided", some people would go for "undecided" as their default answer for most questions. Which could be a point about the randomness in QM, it also feels like symmetry breaking.)

 

[iste]

Barandes had done good work on QM foundations before he fouled himself into believing that he has a new formulation of QM (similar to Feynman's path integral formulation) or solved the interpretation of the measurement problem.

Why isn't it a new formulation? I would say it solves the measurement problem in its own context as a full formulation, Bohm does similar, and Many Worlds if I am not mistaken. Maybe an emergence of classical world is needed for a full explanation, which I think for Barandes involves decoherence.

 

[gentzen]

Why isn't it a new formulation?

It is not a new formulation, because it is not comparable to Feynman's path integrals, to Schrödinger's wave mechanics, to the matrix mechanics of Born and Heisenberg, or to Dirac's transformation theory. And it is simply missing the resources to go from physical situation to mathematical description.

I would say it solves the measurement problem in its own context as a full formulation, Bohm does similar, and Many Worlds if I am not mistaken. Maybe an emergence of classical world is needed for a full explanation, which I think for Barandes involves decoherence.

Bohm and Many Worlds are interpretations. But Barandes himself already noticed that he doesn't have an interpretation in the same sense. So he called it a "formulation" instead. Maybe this was even fine for his first two papers, while he still tried to flesh it out. But in his third paper, he simply declared victory, without actually succeeding to flesh it out any further.

My guess is that what he actually could get if he successfully fleshed out what he has is a "quantum reconstruction", not an "interpretation" or a "formulation":

The pure formalism presented in the two older papers suffered from an unclear status of causal locality. I have not studied the newest paper in any detail yet, but if it manages to overcome this problem, then it constitutes nice incremental progress for this new formulation.

I read some relevant parts of the "new" paper now. I don't think that "it constitutes nice incremental progress for this new formulation". He does his calculation regarding locality in the normal Hilbert space formulation. I admit that he did his definitions regarding locality both in his formulation and in Hilbert space.

Barandes would do better to put his "new formulation" in the context of "quantum reconstructions" rather than "quantum interpretations". (Then he could check whether his math contains new insights, and also whether he was careful enough to show all "expected" continuity properties of his construction with respect to the time parameter t.) And his "Causally Local Formulation" turns out to be just the well known "no signaling" property of QM, verified with calculations done using normal QM (not his new formulation).

 

[Fra]

I am so upset that even you talk of „observers“ now that I have to comment:

I am a not sure I get what is making you upset? Is it about the word "observer"? By observer i mean a physical observer, an agent. If I ever mean a human, I will write physicists, not observer. But I don't think that's what upsetting you?

Maybe I am starting to defend what I wrote now based on misundersstanding your issue with this, but anyways...

One unintuitive feature of QM is that you have to interact with a system to observe it.

How can you possibly or reasonably observe something without interacting with it? For me this is as intuitive as it gets, the opposite is rather unintutive for me.

Classically, I can also alter a system without learning anything about its state prior to the interaction. How does QM change this part? Why can‘t I just forget what I learned during the interaction, if QM should force me to always learn something? Perhaps because my own state was altered nevertheless?

As I see QM, it is not about random (or specifically suboptimal) inference, as there is no lower bound on that. It is about optimal inference, it what is the maximal amount of information we can have about a another system; given some contraints.

In normal QM or Copenhagen interpretation, I think the "observer" is the whole macroscopic environment, so information capacity and processing capacity is not a constraint, the only constraints are that certain information simply does not commute, because they are not independent. Obviously the conjugate variables are not independent - by definition.

Also in normal QM, the backreaction of the whole macroscopic environemnt is ignored.

But when you consider a more realistic observer, ie agents with finite mass, then information capacity and backreaction can no longer be ignored. And this is when it becomes interesting, but this part is also which is not included in current theory and is an open problem. Taking this seriously in a future model, must associate with each "observer" a natural regulator, which implies lossy retention, and the "backreaction" is simply the update of what is normally considered the "background".

(Now you will edit to replace observer by agent, or maybe you already edited. But you and the QBists need to do more to liberate us from this unhealthy focus on observation.)

For me "observation" and "interaction" is just two perpectives of the same thing; there is no contradiction nor equivalence. There is a "tension", which translates into interaction terms, analogous to gauge interactions. So the interaction between observers, is loosely analgous to "gauge interactions". But the symmetries are never perfect, as they might evolve and be emergent. This is why - assuming them to be "complete" leads typically to fine tuning of too big spaces. This is the heart of the problem for me.

The intrinsic "inside view" realtive to one of the participating sytems is "observation", the "extrinsic view" is interaction. But the latter containts more information; and this perspective, when trying to unify forces leads to fine tuning.

The inside view avoids fine tuning as there is a natural normalization, the flip side side is that you get "subjectivity" or "obserber dependence", but there is supposed to be a solution to this - but which is not solved yet. This the "can of worms" I mentiond.

OK, this was a different post which you edited. But still, one of the "possible actions" I thought about was to write to Chris Fuchs and beg him to exand on the non-observer part of agents

I still see a possibilit that I misunderstand you, or that we misunderstand each other on the word observer.

What do you mean by "non-observer part of agents"? If I understand what you mean, I can at least add how I see it.

/Fredrik

 

[iste]

But Barandes himself already noticed that he doesn't have an interpretation in the same sense

Disagree. I think its clear he is espousing a similar interpretation to stochastic mechanics, he just doesn't have a strong explanation of why indivisibility occurs. But then again, neither Bohmians nor Evereytians know why quantum systems behave the way they do in any deeper fashion.

 

[gentzen]

I am a not sure I get what is making you upset? Is it about the word "observer"? By observer i mean a physical observer, an agent. If I ever mean a human, I will write physicists, not observer.

I see. It is not the "human" part which upsets me about the word "observer". It is the suggested absence of "interaction" and "altering"/"influencing" capabilities. The word "observer" suggest a passive viewer of some "TV show" or "cinematic movie", not an active participant in some "massively multiplayer online game".

Or maybe more aptly, it suggests an old time astronomer like in Newton's times watching the planets, moons, and stars without any possibility to alter their course. It does not suggests a modern NASA scientist designing swing-by (gravity assist) maneuvers to steal a tiny amount of the energy of some planet or moon to let his spacecraft save fuel.

What do you mean by "non-observer part of agents"? If I understand what you mean, I can at least add how I see it.

I mean the interaction and altering the system part, including but not limited to the preparation of some system. In QM one sometimes talks about preparing some system in its thermal state by waiting long enough, but other than that, the active part of macroscopic agents is rarely ever discussed.

 

[Fra]

I see. It is not the "human" part which upsets me about the word "observer". It is the suggested absence of "interaction" and "altering"/"influencing" capabilities. The word "observer" suggest a passive viewer

Ah now I see your objection! I do not mean to imply lack of "interaction" - on the contrary do i want to "involve" the observer more than the conventional picture, MUCH more. Which i think should be seem from my other comments.

So I dont think we have a disagreement here. It was misunderstandings.

More later about the actual issue.

/Fredrik

 

[Fra]

I mean the interaction and altering the system part, including but not limited to the preparation of some system. In QM one sometimes talks about preparing some system in its thermal state by waiting long enough, but other than that, the active part of macroscopic agents is rarely ever discussed.

This is not easy to even talk about. This gets deep into the actual problems, that IMO requires a new improved "measurement theory". And this doesn't exists yet, but often the first step is to adopt an "interpretation" which changes the perspective so that progress may or may not be easier.

I don't see Barandes so far said anything about this explicitly.

Avoiding actual theory speculation, just making some suggestions from the interpretational stance of "information processin agents", that I think can be used as a platform, for thinking about an improved theory: (By improved theory i do not mean a alternative math that makes the same predictions, I mean a theory that adds substantial new understanding on unification of forces, solves measurement problems, avoids ad hoc finetuning at ever effective level. etc)

• Every perspective, information or expectation is depending on a context/background. This context limits the memory and information processing capacity, of possible statespaces, constructable measurements(interactions). This context is the "agent" or "observer".
  (This would then REPLACE the macroscopic environment, where the hilbert space is encoded)
• The agent/observer is an active parcitipant in a black box. Everything the agent is inferred and stored in its own memory. (The fact that this is limited - unlike the contnext of a hilbert space; has severe implications, when the scale of the agent, becomes similar to the scale of the quantum part)
• Agent - Material system equivalence, suggests that any real agent is of course simply a physical system, so ther must be a dual descrption: One from the inside (ie observations, actions) and one from the outside. But the two descriptions are not equivalent, and I think just like like C.Rovell (in this relational QM) that there is no "external view"; the only physically possible view, is that from another "fellow agent"! Again agent here does not mean physicists. Protons, atoms, electrons, quarks or whatever are "agents". But not macroscopic one

To dress this in an actual model is where the speculation, and it's an open problem.

But roughly imagine the way one agent influence it's environment; where other agents (=matter) exists, is via some stochastic actions(which is stochastic relative to the agent; not relative to other agents!) and here the agents own expectation of the future, is obviously not genereally divisible, it would be a contradicition.

So to the point where I associate to barandes transition probability; one agent at any time, has a "visible" horizon of distinguishable states, and between these there is a transitiion probabilites. This is the context of the "stochastic actions" of the agent. It is how I interpret this. I have now how idea what Baranders thinks of this. Beeing stochastic means there exists no further explanation. What requires an explanation however, is how this state and transition probabilities came into existende. Here I think one needs to complement with an evolutionary picture of evolving agent populations. And that agent population would at some equilibrium then need to be isomorphic to the standard models particle zoo, and phenomenology. The evoluitionary ide supposedly solves the fine tuining.

To try to "play with this", one needs to start with "toy models", of the agents, and consider what happens when a system of such make inferences on each other ~ which of course is just a difference perspective of systems inteacting. Ie we have learning systems, instead of hamilotonian flows. Emergence instead of finetuned infinite spaces. This is actually going to be closely related to interacting ai agents, which uses both reinforced and evolutionary learning. So ultimately I think the future of the qbist interpreation, mates very well with some ai research. That is also the connection to "optimal inference", that QM says what we "infer" about nature, and that is all there is. And if you take this very seriously, and consider that all matter is like this, then physical forces could be like a litteral game of expectations. The question of what is the "true" ontology is not possible to distinguish from the normal infereence and learning process.

This is my view in brief of this, not sure if it make anything clerer and hope it's not considered specualtions, because they are not IMO. Speculations needss to be much more explicit, this is why this is fuzzy and interpretational only. It otherwise gets impossible to discuss our views open problems or interpretations of current research such as barandes.

It is just my personal views withing the context of the wider family of qbist or interacting agent interpretations, and it's from this stance i see Barandes works as nice, but alot is missing. But as noone has the full answers, not need to pick on incompletness, he is at least providing parts of a new perspective.

/Fredrik

 

[physika]

the question is why should there be observer-dependence?

Right, Why ?

and the process of "individuation" of "observers", shady, ontologically; arbitrary or unfounded.

......

 

[Fra]

Sure, but the question is why should there be observer-dependence?

Right, Why ?

and the process of "individuation" of "observers", shady, ontologically; arbitrary or unfounded.......

I see it as an unavoidable connectivity between ontology and epistemology. They are in my view, not opposites, they are complementary. You can't have one without the other.

Everything needs a context/foundation/premise, to build onto.

For example, mathematics and needs a context, which is a bunch of axioms; they can also be accused for beeing shady, ontologically; arbitrary or unfounded?

Also to be able to hold/encode information (of anything) you need a context, which is some memory structure. One may say this memory microstructure is shady, ontologically; arbitrary or unfounded? For example the microstructure of a string in an embeddd space. This is the CONTEXT of string theory; and to say that it is shady is probably and understatement.

To be able to formulate a question; or construct a measurement; you need a language, or context for the preparatory processes. This is not something that happens in vaccuum.

So scientific knowledge needs to be stored somewhere, and the process of inquiry needs a context. At human science level this is of course physisicsts, advancing human technology, that is rooted in solid macroscopic realm which is effectively classical.

So ther has to be a starting point; a context, for holding/encoding an expecatation, and to structure and manipulate input, to produce output. There is an unavoidable need for this as I see.

In physics this has always been the case; SR and GR the "observer" is simplified to an "observational coordinate frame"; the "observer" is not thought of as having a microstructure etc". In normal QM, we still ahve the spacetime background, but also we need the "context" to accumulate and hold statistics somehow, to be able to verify this in real experiments, preparattions needs to be controlled to the point that they can be repeated, and we collect the dat. This requires a huge non-trivial context. All this is the agent/observer.

But this revision of the contex is incomplete, the divergenses and renormalisation that keep popping up in physics, is I think beceuase we "force" too much information into the theory context; this is pathological and I think it's related to exactly this; our understnading of the "context" of the theory, that this is dynamical and should be thought of as an "agent" that is interacting, not passive.

This is what this is about for me. And the puzzle is still there.

Why do interference patterns occur due to adding slits?

For me the alternative explanation alterntaive to the reglar "complex wave interference" stuff, is that the whole system can be tought of as interacting agents/(subcontext,subsystems

The source, slit and detector.

The interaction between these parts (in the interpretation I subscribe to) can be DESCRIBED by an external observer, but then the evolution has to be inferred with some tomographic process first. The better expolanatory view is from the perspecitve of the parts themselves, and here the source, the slit and the detectors have initially information and expectations of each other. All of them are complete and biased, but that is how it is. And the interaction between these is best understood not in terms of hidden reality, but in terms of how theire expectations influence their actions to the other parts, and this will then give the interference effects. And parts of this involves, that the expected evolution relative to each part, are never divisible, the "divisions" are only where the parts update its expectation via input/output operatins.

Attempting to go into more detail would take us into speculations, as one has to assume "properties".

And finally; the "solution" to the "you can't have one without the other" and the lack of objectivity is supposed to be; emergence of objectivity via evolutionary process. And the insight is that there is not unitary description of evolutionary processes; it's the wrong approach. This is where agent based models provide better perspective than system dynamics.

/Fredrik

 

[gentzen]

One unintuitive feature of QM is that you have to interact with a system to observe it.

How can you possibly or reasonably observe something without interacting with it? For me this is as intuitive as it gets, the opposite is rather unintutive for me.

Are you really sure that it is intuitive? Let's say "we" (i.e. our observatories and telescopes) look at Proxima Centauri, resolve the dark and bright lines in its spectrum, study spectral doppler shifts and brightness variations, and use this data to make deductions/inferences about its chemical composition and its planets. It is more than 4 light years away, so in which sense is it intuitive to you that we interacted with this system, including

And this interaction alters the system.

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).

Classically, I can also alter a system without learning anything about its state prior to the interaction. How does QM change this part? Why can‘t I just forget what I learned during the interaction, if QM should force me to always learn something? Perhaps because my own state was altered nevertheless?

As I see QM, it is not about random (or specifically suboptimal) inference, as there is no lower bound on that. It is about optimal inference, it what is the maximal amount of information we can have about a another system; given some contraints.

Thanks, this is a surprisingly fitting answer to my question. Except that for me, the question already starts earlier, namely what exactly is the analogon of the quantum "observation" situation for the quantum "alterning" situation.

But when you consider a more realistic observer, ie agents with finite mass, then information capacity and backreaction can no longer be ignored. And this is when it becomes interesting, but this part is also which is not included in current theory and is an open problem. Taking this seriously in a future model, must associate with each "observer" a natural regulator, which implies lossy retention, and the "backreaction" is simply the update of what is normally considered the "background".

I guess you are proposing "natural regulator" as a nicer name for the quantum "alterning" situation. You are right, I am still looking for a good name, which better conveys this concept. Maybe I should have used "feedback-free control" or "blind control". But I also don't like those. I just want to have a focus on "doing" and "action" without any special attention to observation, not necessarily complete absence of observation.

 

[gentzen]

But this revision of the contex is incomplete, the divergenses and renormalisation that keep popping up in physics, is I think beceuase we "force" too much information into the theory context; this is pathological and I think it's related to exactly this; our understnading of the "context" of the theory, that this is dynamical and should be thought of as an "agent" that is interacting, not passive.

You hope that a change in "interpretation" will fix mathematical issues? Issues whose root cause is no longer a complete mystery, but can today be seen for example in the context of the "Wilsonian view" (ultraviolet divergences), in the context of "boundary condititions"/"topological perspective" (infrared divergences), or ... (point particles vs 1D string) ... (add your own favorite perspective here)?
Why does every solution for a specific problem always has to also cure cancer and solve world hunger?

One thing that Barandes does better than you is that he actually publishes his ideas, even if they are still unfinished and slightly flawed. My impression is that you will never start to publish your thoughts, because they will never be as polished and finished as you hope for, and won't solve all the problems they could possibly solve.

 

[Fra]

Are you really sure that it is intuitive? Let's say "we" (i.e. our observatories and telescopes) look at Proxima Centauri, resolve the dark and bright lines in its spectrum, study spectral doppler shifts and brightness variations, and use this data to make deductions/inferences about its chemical composition and its planets. It is more than 4 light years away, so in which sense is it intuitive to you that we interacted with this system

By registering/consuming the radiation, and instead emitting something else (noise/heat), we modify the environment of the star, which has consqeuences in principle for the stability of the star. Obviously the effect is minimal in your example, but the principle is clear to me.

I guess you are proposing "natural regulator"

Yes one that has a physical basis, unlike "fictional" regulators used in renormalisation. With the natural regulators built-in, the divergence should not appear in the first place. Without speculating about the explicit relation and relation to entropy etc, intutively, the mass of an agent, is a highly probable natural regulator. In inference this would then also likely relate to confidence or "inertia" of statespaces. This is a mathematical problem, but it is alot easier to think about if you can find an intutitive handle

/Fredrik

 

[Fra]

You hope that a change in "interpretation" will fix mathematical issues?

Of course not, we will not solve anything by "pure interpretations". For the me change of interpretation is a way to align and focus the research in a specific direction. The fix is a new theory. But how do we find a new theory without intutive guidance?

One thing that Barandes does better than you is that he actually publishes his ideas, even if they are still unfinished and slightly flawed. My impression is that you will never start to publish your thoughts, because they will never be as polished and finished as you hope for, and won't solve all the problems they could possibly solve.

That's a good point. But my ideas grind slowly, as i have a normal job. I like to get things right, rather than be fast. I have no pressure to publish anything. When I feel it's worth publishing it will come, but there is enough mumbo jumbo already that I don't need to add more.

/Fredrik

 

[nPoE]

Seems the obvious implication of this thread is that many in the field disguise their bitterness and ego in the guise of rigor while it not being entirely clear they are rigorous. I am very unsure that education makes us better in the human sense. Its a pity, so many Elons.

 

[gentzen]

Seems the obvious implication of this thread is that many in the field disguise their bitterness and ego in the guise of rigor while it not being entirely clear they are rigorous. I am very unsure that education makes us better in the human sense. Its a pity, so many Elons.

Don't missinterpret my exchange with Fra/Fredrik as bitterness. I am having this exchange with him, because I know that he can understand the direction into which I am thinking, and is willing to answer and discuss this stuff.

As for Barandes, I guess you mean that me and the others who are skeptical about his latest paper ask for more rigor than we ourselves would be able to provide. Yes, I also would like more rigor. But more than that, I wish Barandes would correctly put his work into the context of existing investigations into the foundations of QM. Comparing his work to the Feyman path integral formulation is not helpful here.

 

[Fra]

I think there is two kinds of "rigor" here, that needs to be in balance.

Mathematical rigor and what one might call perhaps "conceptual rigor/clarity" or maybe there is a better term?

Axiomatic constructions of physical theories can be as rigorous as mathematics. But if the mapping of this axiomatic structure to our conceptual understanding of physical reality is too ambigous, then we lack conceptual rigor.

But it seems this conceptual rigor is related to the choice of interpretation, and choice of primitive ontologies, almost like an axiom system for conceptual understanding; so for any given mathematical theory there is perhaps an interpretation where the conceptual clarify is highest.

In this case, it's the mathematical description of "observation" "observable" and "observer" that lacks a matching coherent conceptual clarity; and intutitively there is also some mismatch here as the mathematical versions here more corresponds to some asymptotic scenarios. That's generates the obvious question; what are the generalisations of the "observables" and "obserevers" to the actual non-asymptotic cases? These cases are what I have labeled "inside observers". Ie. more realistic observers, in constrast to the asymptotical limiting cases that I think QM and QFT corresponds to.

But the insight is also that this is fine for small subsystems like atomic systems! Because we meet the asypmtotic approximates well enough in finite times in our experiments! But what when we dont get away with this? Then we can not hide at the horizon anymore.

If we don't grasp these very basic things, playing around with mathematical models in isolation will not increase any understanding, at least it's how i feel about this.

/Fredrik

 

[iste]

It will release in a couple of days, and then we have to watch about 1-2 hours of it, it can wait.

Do you happen to know when it is coming out?

 

[pines-demon]

Do you happen to know when it is coming out?

2h ago.

Here it is:


I will update later this week, whenever I get time to listen to it.

 

[iste]

2h ago.

Here it is:


I will update later this week, whenever I get time to listen to it.

Ah, thanks. Good timing.

 

[pines-demon]

Ah, thanks. Good timing.

Ok here is my review of this second part of the podcast. The podcast is long but very interesting from a history of physics perspective. I think Barandes clarifies some misconceptions that some physicists have about Bell and other interpretational issues in quantum mechanics. He also proposes some interesting ideas like that someone should work on a classical probabilistic theory for general relativity (inexistent as far as he knows).

However the podcast is too long compared to what he actually get. Concerning NMIS processes he has some favorable things to clarify:

• Barandes dropped describing his reformulation as a memory effect
• He does see his reformulation as an interpretation and argues that it is a better alternative than Bohmian mechanics
• His reformulation does not indicate what is the true nature of physics (it could be particles, waves, fields, qubits or whatever, the reformulation is very flexible)
• He addresses my criticism of the misuse of Reichenbach principle, he agrees that is not exactly what Bell meant (he says that somebody pointed that to him)

These are the things that I do not get

• He says that his reformulation bypasses Bell factorization (or Reichenbach principle) by redefining the "microscopic theory of causation". The details are apparently in this paper https://arxiv.org/abs/2402.16935 and in his talks. However as I have said before his Bell talk does not discuss his redefinition. I will try to read the paper.
• He says that his approach bypasses all the need of interference and complex phases in the presence of a measurement device. How? It is unclear.
• [From podcast part 1] He still did not provide a simple example of indivisibility. We still have to wait for his double slit interference paper.

So again he is claiming a new interpretation that erases the need of quantumness (interference and entanglement). I still worry that his picture is not that simple and that he has just found some mathematical duality, but I might be wrong. Hope this helps.

 

[Fra]

https://arxiv.org/abs/2402.16935

Thanks for the link, the talks and paper deserves proper reading. I will get back as well when i had time to read/listen.

I quickly skimmed a bit of it + the talk and I again tend to get along well with his reasoning, and he acknowledge serious deep issues where he has no answer which are keys. The fact that he mentions qm + gr issues and howto view spacetime indicates to me that he at least does not hold a naive view on this.

If i remeber correctly from an incomplete listening in the car yesterday he pondered about that a stochastic formulation of gr may automatically gi e qm? I like it. The hunch is also the the quest for local beables that respects some causal locality and ia stochastic is if not the same closely relates to the "intrisic" or "inside observer" views that current theory explicitly lacks. He argues it seems that bell inequality does not forbid this, and i agree. He seems to highlight the "right problems" and this encourages me to read more carefully to see if i can find the deeper connection

/Fredrik

 

[JC_Silver]

• He says that his approach bypasses all the need of interference and complex phases in the presence of a measurement device. How? It is unclear.

To me it seems that he is arguing that indivisibility would be akin to superposition, however instead of the particle "becoming" a wavefunction and interfering with itself, the particle (or small system) is in a state where its behaviour is unknown, it could be anything (eg. particles aren't real, many worlds are happening at the same time, spacetime is superweird, strings are stringing, whatever) that is non-Markovian and indivisible (t' is not independent of t and the system's evolution cannot be divided such as t->t'=t->t¹+t¹->t'). It's not that the particle itself became a wavefunction, but that the particle is following some physics between point t and t' and if you want to know the probability between t and t' you can use a wavefunction, but that doesn't tell you what actually happened between t and t', because in an indivisible processes there is no t->t¹+t¹->t' that gives a correct prediction of t->t'.

The wavefunction (and with it interference and complex phases) describes how our expectation of the probability should evolve, but doesn't really describe the reality between t and t', because for us to be able to actually tell what is happening between t and t' we'd break indivisibility.

(Honestly, I wrote several paragraphs here but everytime I finish and read it, it turns out I have just described regular old QM using 'indivisibility' and 'division event' in place of 'superposition' and 'collapse')

 

[Fra]

I looked at https://arxiv.org/abs/2402.16935 and I think the interesting

These are the things that I do not get

• He says that his reformulation bypasses Bell factorization (or Reichenbach principle) by redefining the "microscopic theory of causation". The details are apparently in this paper https://arxiv.org/abs/2402.16935 and in his talks. However as I have said before his Bell talk does not discuss his redefinition. I will try to read the paper.

The mere reformulation from indivisible stochastics to hilbert formalism is not the most interesting part, it is in a way some equivalent formulation as others suggested, but the important part (for me at least) is the understanding of causation, but now as i read what he suggests, it does looke like ideas diverge from what I hope for.

That parts that is conceptually unclear to me is this when he tries to define the new improved principle of causal locality, he starts by considering a decomposition one unistochastic system into two parts, that are furthermore spacelike separated on page 11... and then he goes on from there.

This seems very nontrivial to me, when trying to squeeze this through the "agent perspective", and has two suspicious parts.

The first issue is that the decomposition of one system into independent parts us problematic from how I want to see it, as the "view of one agent" is always holistic; as I think in a way there is only one "system" from the perspective of an agent; and it is the whole environment. If you decompose it into parts, there is bound to be some relation - at least via some memory capacity constraints, that leaves at least a subtle dependence between the two, in some holographic sense that an image of everything is always encoded in every part, suggesting that a complete independence in principle of even seem counterintutitive to me.

The other issue is that he introduces space (which I expect eventually to be emergent in some way; after all in his early discussions the index of states in the configuration space is abstract! It is an abstract space of distinguishable states, there is at that pooint now reference to 3D or 4D metrics; but now from nowhere spacelike notion enters. this is too fast for me for a conceptual reconstruction; but fine for a reformulation).

I'll ponder about this a bit more, but this is my current state of confusion on the matter. I think the emergence and origin of the transition matrixes; and in particular how it works when you consider a union of two such systems, is wherin the possible clarification to this may be found?? And this unavoidably brings us to the topic of ununification of both all forces and the metric distanaces between parts (space).

But again Baranders mentions in the youtube talk that he thinkg there is alot of research to be done, that can explore many things, including seeking a stochastic interpretation of GR; and perhaps that can yield surprises... I think so to.

So I think the difficulty to understand this, or Barandes ideas is that many problems are interconnected. So it's a mess, but a very interesting mess.

/Fredrik

 

[Fra]

(Honestly, I wrote several paragraphs here but everytime I finish and read it, it turns out I have just described regular old QM using 'indivisibility' and 'division event' in place of 'superposition' and 'collapse')

I think you have a point here, and it's why I think a better understanding of nature of causation, rather than a new mathematical formulation, is the main take away I was hoping for here.

If we are just as confused by indivisibility or non-markovianity as we we with the hilbert features, what have we gained. And to understand these things, I think they causation or even what causation means in a "newtonian paradigm/schema", is the heart of the matter. Baranders stress this as well in his youtoube clip, and I enjoyed to hear it.

/Fredrik

 

[pines-demon]

Hello, excuse me for bothering you. I am a beginner, and I would like to understand what the potential issues are in Barrande's approach.

Most common potential issues pointed out are that it does not provide an interpretation (or at least not an easily dissectable one). Also it claims to deflate any issues of quantumness (entanglement might be local, interference is an illusion and more).

Some of us just think that he found a nice mathematical relation between quantum systems and a particular kind of stochastic processes. The interpretational power of that analogy is still under discussion.

 

[physika]

stochastic GR

......

 

[gentzen]

I have another question: would it be possible to test Barrande's approach to confirm that it reproduces the experimental results of quantum mechanics (such as the violation of Bell's inequalities or the GHZ state), which would be an indication of its viability?

I don't think so, because

It is not a new formulation, because it is not comparable to Feynman's path integrals, to Schrödinger's wave mechanics, to the matrix mechanics of Born and Heisenberg, or to Dirac's transformation theory. And it is simply missing the resources to go from physical situation to mathematical description.

It doesn't make predictions. So it is not in the business to reproduce experimental results or not.

And it should be the task of Barandes to clarify how his approach fits into existing categories. I personally would put into the "quantum reconstruction" category. But if Barandes would propose another fitting category, that would be fine for me too.

Finally, Barrande with curt jaimungal has published a new video on his approach if that might interest you.

You mean the one mentioned in this post? Or the recent ToE video with Jacob Barandes and Manolis Kellis mentioned in this post? Or is there yet another new one?

 

[gentzen]

But again Baranders mentions in the youtube talk that he thinkg there is alot of research to be done, that can explore many things, including seeking a stochastic interpretation of GR; and perhaps that can yield surprises... I think so to.

stochastic GR;

Not sure what you mean by "". Barandes really mentioned it in the video, just like Fra reports. You want us to give a specific timestamp where he does? Or you mean that Barandes' idea is not so great after all?

 

[physika]

Not sure what you mean by "". Barandes really mentioned it in the video, just like Fra reports. You want us to give a specific timestamp where he does? Or you mean that Barandes' idea is not so great after all?

Sounds Interesting, but...
let me digest first.

 

[iste]

He says that his reformulation bypasses Bell factorization (or Reichenbach principle) by redefining the "microscopic theory of causation". The details are apparently in this paper https://arxiv.org/abs/2402.16935 and in his talks. However as I have said before his Bell talk does not discuss his redefinition. I will try to read the paper.

My issue is that what he shows doesn't seem to be that novel, but just seems to reiterate something like the kind of no-signaling property that is already well-known, as someone else in the thread pointed out. Its then unlikely to convince anyone into thinking that quantum mechanics is local - i.e. "if I already knew about this property when I thought quantum theory was non-local, how is reiterating it going to change my mind?". I guess though that with no collapse, a significant purported source of non-locality is gone from Barandes' theory.

Funnily enough, there is non-local causation in the system before measurement, under his definitions; but he appeals to the fact that this is directly because the indivisible stochastic matrices encode the local interaction at t0, and so this non-local causation is due to the local interaction in the past light cone. I think its fair to criticize the Bell inequalities in the sense that the common cause assumption Barandes talks about isn't applicable to the initial local interaction, but neither does his alternative view of causation seem applicable either. I think appealing to the properties of the indivisible transition matrix may still actually be fair to justify locality here, and maybe more interesting than the no-signalling result. But, because there is no transparency about why and how exactly indivisibility occurs (but I think what indivisibility means is relatively straightforward) this doesn't seem so satisfying.

I think another fair criticism of Bell inequality is the observation that while factorizability corresponds to Bell locality, there is also a strict equivalence between factorizability and the existence of global sections (e.g. joint probability distributions): e.g.

https://iopscience.iop.org/article/10.1088/1367-2630/13/11/113036/meta
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.48.291
https://pubs.aip.org/aip/jmp/articl.../Joint-distributions-quantum-correlations-and
https://link.springer.com/chapter/10.1007/978-94-017-0849-4_6

This seems like a major conflation since it implies locality must be characterized by a global joint probability distribution despite the fact that this same property systematically breaks down regardless in quantum theory due to non-commuting observables. The question is then:

Why does locality / local causality require the presence of joint probability distributions especially when we are talking about the kinds of things that cannot be straightforwardly plugged into the common cause criteria Barandes mentions?

This doesn't seem reasonable me (but I very well could be missing something here!).

Albeit, I don't think someone like Barandes can truly succeed in convincing that the conception of local causation he favors is truly valid here until he can give an intuitive explanation of how the measurement results seem to depend on both spatially separated measurement settings in a Bell scenario.

He says that his approach bypasses all the need of interference and complex phases in the presence of a measurement device. How? It is unclear.

He is just saying that if you were to translate from the Hilbert space representation to the indivisible stochastic one, you cannot reproduce the quantum predictions without explicitly including measurement devices as components of the indivisible stochastic system. When you translate back into the Hilbert space representation, the measurement device's role in disturbing the stochastic dynamics is incorporated into the phase so that the measurement device no longer is required to be explicitly represented in the measurement process. The need to explicitly incorporate the measurement device is also shared in Bohmian mechanics: (section vii, from page 49)

https://arxiv.org/abs/1206.1084

It also seems to be the case in Nelsonian stochastic mechanics and I think there is some reason to believe that it also corroborates what he says about the phase.

 

[Fra]

Funnily enough, there is non-local causation in the system before measurement, under his definitions; but he appeals to the fact that this is directly because the indivisible stochastic matrices encode the local interaction at t0, and so this non-local causation is due to the local interaction in the past light cone

I think your issues are related to those I have. The problem I have is explicitly that if we have a new understanding of causal influence, then this likely must come with implications or constraints on the possible transition matrixes (or equivalently the possible hamiltonians). And trying to understand the construction and structure of the transition matrix or hamiltionians in fundamental ways, is precisely one of the things the quest for unification of forces is about. And if one starts to talke about "spacelike" distances between PARTS of this transition matrix, that really needs qualifications I think.
If we just "assume there is an transition matrix" in this configuration space and we understand that no better than the "assume there is this hamiltonian" in this hilbert space, then IMO we have not gained much conceptually.

But I do see a way to make something out of this, but Barandes reasoning in https://arxiv.org/abs/2402.16935 takes a different path from what I would prefer.

OTOH, if you really want to question the makeup, structure and phenomenolgoy of the space of all transition matrices from first principle abstract configuration spaces, then you obviously immediately dissolve spacetime as we know it to (this is also the connection to reconstructing GR). And things really get complicated. Much more complicated. In particular it gets circular, so an evolutionary approach seems unavoidable; to avoid finetuning situations. Does Barandes want to avoid going there?

The real question, is where the "observer/agent" is in Baranders view? Specifically the subsystem Q and R he talks about on page 11; do we associate them to TWO different observers, or a decomposition of the whole system from the perspective of one observer? For me, this makes a big difference.

For me personally, what is clear is that the causal influence on the intrinsic actions of two observers are limited to their intercommunication. In the two abstractions here; agent-agent interactions, vs part-part interactions from the perspective of the "newtonian schema/paradigm", there is as Baranders also hints a in his video, not even clear what "causal influence" MEANS in the newtonian paradigm? All we can infer is a correlation, the "causal notion" is a fiction - UNLESS we switch to the agent perspective, then it IMO becomes clear. The causal influence is simply that the agents reactions to the extent that its not just stochastic, is only modulated by it's inputs (as received from the environmnet). So no physical communication - no influence; is built in.

If we associate internal observer to Q and R, what Baranders says makes a little more sense, but brining in spacemeasures this fast, without explaining how the relation between the agents, define this metric withou referring to external spacetime.

My given all the research questions Baranders mentions in the youtube video, I it seems thta this stochastic quantum correspondence is by no means meant to be "complete". So it is probably unfair to expect all solutions at once. But at the same time, it is at least the promise of solutions, that motivates most of us I think for seeking new perspectives, from where solutions problems become more feasible.

And I think gentzen has a good point, that having the ambition to solve at once becomes unsurmountable; yet when you are convinced that things are deeply interconnected, progress becomes difficult and every step forward is unavoidably going to have some deep flaws. So I think we might need to view the new correspondence with an open mind.

/Fredrik

 

[iste]

The real question, is where the "observer/agent" is in Baranders view? Specifically the subsystem Q and R he talks about on page 11; do we associate them to TWO different observers, or a decomposition of the whole system from the perspective of one observer? For me, this makes a big difference.

Q, R, A and B in that paper are all just physical systems as they would exist objectively and independent of any kind of observer. A and B are physical systems that take the role of measurement devices; A and B are therefore observers but in the deflationary sense that an observer is just any kind of physical system whose states have some specific relationship to the states of other systems that they are measuring. Nothing special. The whole system including A, B, Q, R is a physical system as would objectively exist independently of some other observers. In fact, you see in same parts of that paper that Barandes explicitly wants to do away with the notion of agents in his description. It is agent-less causality.

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. It may be a useful, even "real", construct in some scientific and other intellectual fields; but from the perspective of physics or neurobiology, it is like a convenient fiction (perhaps idealization or stop-gap is better). Agentive causality then reduces to the kind of causality that Barandes is talking about in the paper - about atoms influencing each other in a directed ways, at least trying to construct a notion of that which makes sense.

 

[Fra]

Q, R, A and B in that paper are all just physical systems as they would exist objectively and independent of any kind of observer. A and B are physical systems that take the role of measurement devices; A and B are therefore observers but in the deflationary sense that an observer is just any kind of physical system whose states have some specific relationship to the states of other systems that they are measuring. Nothing special. The whole system including A, B, Q, R is a physical system as would objectively exist independently of some other observers. In fact, you see in same parts of that paper that Barandes explicitly wants to do away with the notion of agents in his description. It is agent-less causality.

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. It may be a useful, even "real", construct in some scientific and other intellectual fields; but from the perspective of physics or neurobiology, it is like a convenient fiction (perhaps idealization or stop-gap is better). Agentive causality then reduces to the kind of causality that Barandes is talking about in the paper - about atoms influencing each other in a directed ways, at least trying to construct a notion of that which makes sense.

I see what you are saying, but my own biggest reason for thinking this way is not something that is evident in Baranders paper. My bigger perspecitve is unification, not just "interpretations". There is more to it than the fact that as we know already, there are two ways to model systems of interacting parts;

1) System dynamics (meaning there is differential equations), state spaces and initial or boundary conditions. This is a top down approach. It typically requires finetuning of the system dynamics; in a ways that makes it "effective", it is not always obvious how to parameterise a differnt system.

2) Agent based models, is a bottom up approach where one models the local interaction between the parts, and the big picture is emergent. This often leads to better insight into local mechanism.

The exploit I see is that agent based models, has chance to put strong constraints in theory space - just like string theory; except string theory is a bit weird; the continous string embedded in a higher dimensional background is non-trivial and has it's own finetuing problems. It's background dependence is what prevents it from beeing what it could have been.

So my personal preference for the agent centerted view goes beyond what we discussed so far. But going into that is off topic.

/Fredrik

 

[gentzen]

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.

I would not be so quick in dismissing "agents" at our current state of "capabilities". The interpretation of statistical results from randomized controlled trials currently needs the assumption of active interventions. And Judea Pearl's causal inference didn't (yet) manage to get completely rid of this either:

These are causal questions because they require some knowledge of the data-generating process; they cannot be computed from the data alone, nor from the distributions that govern the data.

I rather think, before getting rid of agents, we first have to embrace them more seriously:

Or maybe more aptly, it suggests an old time astronomer like in Newton's times watching the planets, moons, and stars without any possibility to alter their course. It does not suggests a modern NASA scientist designing swing-by (gravity assist) maneuvers to steal a tiny amount of the energy of some planet or moon to let his spacecraft save fuel.

Of course, the course of the planet or moon is not significantly altered, but the course of the spacecraft is. You could model the spacecraft itself as an agent, because it has thrusters which are effectively controlled by intentions (i.e. final causes). It can also make sense to only model the ground station as an agent, because the communication delay to the spacecraft might be important. But beyond that, the usefullness and explanatory value of the model would rather decrease if you try to remove agents even further.

I admit that trying to develop theoretical frameworks which are less dependent on agents for their explanatory power is a worthwhile goal. I am in full support of A. Neumaier's thermal interpretation, which includes a convincing non-subjective interpretation of probabilities. But we should also admit that we are not there yet, and that we currently have no idea how that goal to get rid of agents in our models could ever be reached.

It may be a useful, even "real", construct in some scientific and other intellectual fields; but from the perspective of physics or neurobiology, it is like a convenient fiction (perhaps idealization or stop-gap is better).

Maybe it is a "stop-gap", but "gap" suggests something small. But it is not a "small gap", it is a "huge chasm"!

Agentive causality then reduces to the kind of causality that Barandes is talking about in the paper - about atoms influencing each other in a directed ways, at least trying to construct a notion of that which makes sense.

There is also a question as to how many agents are there. Fra's initial answer to my "in which sense is it intuitive to you" question was a wordy "the principle is clear to me":

Are you really sure that it is intuitive? Let's say "we" (i.e. our observatories and telescopes) look at Proxima Centauri, resolve the dark and bright lines in its spectrum, study spectral doppler shifts and brightness variations, and use this data to make deductions/inferences about its chemical composition and its planets. It is more than 4 light years away, so in which sense is it intuitive to you that we interacted with this system

By registering/consuming the radiation, and instead emitting something else (noise/heat), we modify the environment of the star, which has consqeuences in principle for the stability of the star. Obviously the effect is minimal in your example, but the principle is clear to me.

But in a later seemingly unrelated post, Fra gave a better answer, namely that it isn't a multiagent perspective at all:

The first issue is that the decomposition of one system into independent parts us problematic from how I want to see it, as the "view of one agent" is always holistic; as I think in a way there is only one "system" from the perspective of an agent; and it is the whole environment. If you decompose it into parts, there is bound to be some relation - at least via some memory capacity constraints, that leaves at least a subtle dependence between the two, in some holographic sense that an image of everything is always encoded in every part, suggesting that a complete independence in principle of even seem counterintutitive to me.

The picture is just one agent, one system, one environment. Which is an important point. If you look at the explanatory role of agents in models, one agent always seems to be enough (from the perspective of physics or neurobiology).

So I guess we should at least stay long enough in the picture with "agents", until we have clarified how many agents would actually be helpful for explanatory strenght (and insights), for a specific given scientific problem.

 

[Fra]

I rather think, before getting rid of agents, we first have to embrace them more seriously:

I agree, but "getting rid of" them meaning what? They are after hand the handles into actual observation and interaction. We need to "break" this invariance to touch based with reality.

IMO a conceptually undeniable argument against "agent/observer dependence", is the principle that there is no preferred observer, among the set of possible choices. But this is not the same as saying you do not need an observer! Without the set of actual obserers, the principle is empty!

This is the key constructing principle in both special and general relativity for the "class of observers" that are just generated by moving around in spacetime.

One way to attempt to satisfy this requirement is if you find a transformation that defines the observer equivalence, for example the poincare transformation. If we can do this, great and fine.

But such an equivalence transformation presumes that all observers, can encode the same amount of information and perhaps even unlimited information; otherwise there can't possible be an equivalence. This means, different observers have different amount of information and even different information as all records may be lossy, but it does not necessarily mean one is more right.

If this is not so, the principle of no preferred observer, does not imply observer equivalence, but implies what I think of as "observer democracy" (which indeed gets more complex).

But in neither case do I think it makes sense to think that the observers is not needed as elements in the fundamental theory.

/Fredrik

 

[iste]

I would not be so quick in dismissing "agents" at our current state of "capabilities". The interpretation of statistical results from randomized controlled trials currently needs the assumption of active interventions. And Judea Pearl's causal inference didn't (yet) manage to get completely rid of this either:

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".

But we should also admit that we are not there yet, and that we currently have no idea how that goal to get rid of agents in our models could ever be reached.

It genuinely doesn't seem that hard to me. Barandes' approach has no agents or observers and I don't see why it should need them 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. If Barandes theory were able to recreate all the predictions of quantun theory, why need them? Its just completely unnecessary.

 

[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.