I was reading up on the theory and apparently it's saying stuff that is in direct opposition with current views like how there is no wave function, but that quantum processes occur by randomness? I'm not sure how valid it might be but all I know is that it's a massive departure from the usual stuff.

Moderator's note: Thread moved to the QM interpretations subforum.

DarkloidNeos said:

I was reading up on the theory

Where? Please give a specific reference. "The indivisible interpretation" is not any recognized interpretation that I've heard of.

DarkloidNeos said:

Ah, ok. This references several papers by Jacob Barandes, whose work has been discussed in previous PF threads. This one is probably the best place to start:

As far as how "valid" this interpretation is, that's a meaningless question for any QM interpretation. All of them make the same predictions for experimental results, so there's no way to test them against each other by experiment. So it comes down to personal preferences about what kind of story to tell about what is "really happening" in quantum experiments.

If you want to read something recent from Jacob Barandes, I would rather go with

javisot said:

https://arxiv.org/abs/2602.09397 "historical debates over the physical reality of the wave functions", J.Barandes

Barandes certainly has his reasons why he proposed his "indivisible stochastic process" interpretation: A wavefunction in configuration space is not a thing we would normally call "real". So he goes with a stochastic trajectory in a state space instead. It is consistent and doesn't contradict the math of QM. However, those trajectories lack "causal power". This is a phenomenon I first read about in "Do we really understand quantum mechanics?" by Franck Laloë when he described modal interpretations and their issues.

In contrast, trajectories in Bohmian mechanics don't lack "causal power" in the same way. This may seem surprising first, because they just seem to go where the wavefunction directs them, without affecting the wavefunction itself.

As interpretations are mostly "what feels right" philosophically, I can argue that it does not help much in understanding the concept of entanglement. It "feels as weird" as Bohmian mechanics or superdeterminism in that regard.

Mathematically it is much interesting as it provides a duality between an explored field of knowledge (quantum mechanics) and the completely unexplored world of indivisible stochastic mechanics (if this field is helpful for anything is yet to be answered).

So, dressing the same physics up in a different mathematical framework definitely can have value. However, how is this mathematical formalism more realistic than what one started with? QM things still do QM things.

Paul Colby said:

However, how is this mathematical formalism more realistic than what one started with? QM things still do QM things.

Define realistic.

pines-demon said:

Clearly, I can’t. Which is also my point. Neither has anyone else. I’m also not the one employing such a term.

Paul Colby said:

Clearly, I can’t. Which is also my point. Neither has anyone else. I’m also not the one employing such a term.

Any definition will do. All interpretations are physically valid (in the sense that predict the same phenomena). So at this point one just needs to indicate what kind of criteria they want more and we can argue which interpretation approximates that criteria better.

pines-demon said:

Here is Barandes' own definition from the abstract:

Jacob Barandes said:

This paper provides a detailed historical account of early debates over wave-function realism, the modern term for the view that the wave function of quantum theory is physically real. As this paper will show, the idea of physical waves associated with particles had its roots in work by Einstein and de Broglie, who both originally thought of these waves as propagating in three-dimensional physical space. [...] The present work will argue that this move from three-dimensional physical space to a many-dimensional configuration space was a key reason why the founders of quantum theory uniformly abandoned the physical reality of the wave function.

gentzen said:

Here is Barandes' own definition from the abstract:

Although it is a "problematic" term, I think the definition of realism in quantum foundations is generally linked to the idea that systems possess properties outside of measurements (just as in the EPR paper), whereas Barandes' quote refers specifically to "wave function realism", more in line with the usual ##\psi##-ontic vs. ##\psi##-epistemic debate.

Lucas.

Sambuco said:

Although it is a "problematic" term, I think the definition of realism in quantum foundations is generally linked to the idea that systems possess properties outside of measurements (just as in the EPR paper), whereas Barandes' quote refers specifically to "wave function realism", more in line with the usual ##\psi##-ontic vs. ##\psi##-epistemic debate.

gentzen said:

Here is Barandes' own definition from the abstract:

To be fair I was asking for definition of "realistic" which I would say is more about the interpretation being pragmatic than adhering to whatever "realism" means.

pines-demon said:

I agree. In philosophy any statement X may be argued as well as any statement not X with no acceptable means of determining which, if any[1], is to be preferred.

[1] don’t leave out any middles.

Sambuco said:

I think the definition of realism in quantum foundations is generally linked to the idea that systems possess properties outside of measurements (just as in the EPR paper)

Yes, in "quantum foundations". That is why I said "normally":

gentzen said:

A wavefunction in configuration space is not a thing we would normally call "real".

This is about understanding Barandes' motivations, not necessarily about agreeing with him.

sbrothy said:

We should have more interpretations named after cities, having just two is unfortunate.

pines-demon said:

We should have more interpretations named after cities, having just two is unfortunate.

There's the ETH interpretation of QM. ETH stands for events, trees, and histories, but I suspect it is a nod to ETH Zurich.

gentzen said:

Yeah, I may have underestimated it. But isn't it a moot point reaching the limit of clocks? Like reaching absolute zero. I may to need some more papers on the topic; and retain better.

gentzen said:

This is an extremely interesting discussion. I wonder how I overlooked it. I realize my math-limits will be a problem understanding this, especially in light of this:

[...] modified Schroedinger equation [...]

I realize it's still time-related but that's kinda the limit of my understanding (and reading).

Still, fascinating.

sbrothy said:

I'd almost love if someone was able to stoop to my level and explain to me why the The Montevideo Interpretation of QM doesn't at least a point to a solution to the measurement problem:

Pretty much every interpretation says it at least points to a solution of the measurement problem, and within the context of each interpretation, what it points to at least appears to make sense. So nobody will be able to give you what you're asking for here. The issue with all QM interpretations is not that they don't offer solutions to conceptual problems with QM; the issue is that we have no way of testing any of them by experiment, because they all make the same predictions for experimental results.

PeterDonis said:

Pretty much every interpretation says it at least points to a solution of the measurement problem, and within the context of each interpretation, what it points to at least appears to make sense. So nobody will be able to give you what you're asking for here. The issue with all QM interpretations is not that they don't offer solutions to conceptual problems with QM; the issue is that we have no way of testing any of them by experiment, because they all make the same predictions for experimental results.

Yeah, and I understand that asking "Why does nature behave like this and not like that?", ("Shut up and calculate!") de facto doesn't make a whole lot of sense. I'm just still under the perhaps naive belief that philosphy of physics might at least uncover new avenues for both theory and experiments!

pines-demon said:

We should have more interpretations named after cities, having just two is unfortunate.

Doesn't this one make it three?

there is also the vaxjo interpretation of quantum mechanics - a swedish city

iste said:

there is also the vaxjo interpretation of quantum mechanics - a swedish city

I'm happier now.

martinbn said:

Doesn't this one make it three?

What is the other one? Copenhagen, Montevideo, (Växjö,) and?

pines-demon said:

What is the other one? Copenhagen, Montevideo, (Växjö,) and?

ETH, Ithaca, ...?

a plethora...

gentzen said:

If you want to read something recent from Jacob Barandes, I would rather go with

Barandes certainly has his reasons why he proposed his "indivisible stochastic process" interpretation: A wavefunction in configuration space is not a thing we would normally call "real". So he goes with a stochastic trajectory in a state space instead. It is consistent and doesn't contradict the math of QM. However, those trajectories lack "causal power". This is a phenomenon I first read about in "Do we really understand quantum mechanics?" by Franck Laloë when he described modal interpretations and their issues.

In contrast, trajectories in Bohmian mechanics don't lack "causal power" in the same way. This may seem surprising first, because they just seem to go where the wavefunction directs them, without affecting the wavefunction itself.

From what I read the lack of causality is a feature and not a bug since it's supposed to break it and suggest that things happen randomly. Though I don't know how accurate that is.