Criteria for a good quantum interpretation

[RUTA]

To my mind, quantum theory is pointing to the metaphysics of neutral monism.

We agree https://www.mdpi.com/1099-4300/22/5/551

 

[bhobba]

'I think the problems and puzzles we are dealing with here will be cleared up, and ... our descendants will look back on us with the same kind of superiority as we now are tempted to feel when we look at people in the late nineteenth century who worried about the ether.'

I know that quote from Bell and I remember 15 or so years ago now, after I came out of my getting to the bottom of Rigged Hilbert Spaces phase, I was really struggling with the question of what is QM. I have reached a certain accomodation now, with what I call a modelling view, although I formally hold to the Ensemble interpretation. I remember when I read it, it was the first time I had seen the idea, and it hit me like a bolt from the blue. The issues will all one day be cleared up - progress is slow - but it is being made. It lifted a big weight from me. In my early days of posting here I had some misconceptions that was cleared up, but after people often commented I had a sort of business as usual approach to QM. That's why. Although a different issue, but may have something to do with QM foundations, I worried a lot about a QM/GR synthesis until I came across the Effective Field Theory approach. I then realized it is exactly the same issue we have with the standard model. We are pretty sure it really is an effective field theory as well - so the real issue is what is beyond the cutoff - usually thought to be about the Planck scale, but of course could occur before that is reached (after is possible too I suppose - but that does not seem likely to me).

Thanks
Bill

 

[atyy]

Or perhaps it will be as ridiculous as the cosmological constant, which Einstein thought was his biggest mistake.

 

[akvadrako]

To my mind, quantum theory is pointing to the metaphysics of neutral monism.

This is the first I've heard of this budding interpretation and it seems like there is a category of neutral monism theories, so can you expand on what you mean?

I imagine you mean something like the subjective parts of QBism without it's objective claims. So saying the quantum state encodes what each user knows and that's it; the users' minds is all of reality.

 

[Demystifier]

Or perhaps it will be as ridiculous as the cosmological constant, which Einstein thought was his biggest mistake.

What does "it" refer to?

 

[Lord Jestocost]

This is the first I've heard of this budding interpretation and it seems like there is a category of neutral monism theories, so can you expand on what you mean?

This is not an interpretation. To my mind, classical physics rest on Descartes’idea that nature is intrinsically divided into two parts: mind (res cogitans) and matter (res extensa). I merely question whether one can futhermore adhere to this idea from the point of view of quantum theory.

Here I follow James Jeans, who puts it in his book “PHYSICS & PHILOSOPY” (1948) in the following way:

“Complete objectivity can only be regained by treating observer and observed as parts of a single system; these must now be supposed to constitute an indivisible whole, which we must now identify with nature, the object of our studies. It now appears that this [the object of our studies, LJ] does not consist of something we perceive, but of our perceptions, it is not the object of the subject-object relation, but the relation itself.”

 

[AlexCaledin]

- and so we come to the Whiteheadian psychophysical event avalanche!

 

[Fra]

My main question was what the world "mind" means in terms of physics? does it actually mean human mind, or is it a metaphore for an abstraction such as observers state etc?

/Fredrik

 

[RUTA]

My main question was what the world "mind" means in terms of physics? does it actually mean human mind, or is it a metaphore for an abstraction such as observers state etc?

/Fredrik

If you're talking about neutral monism, the view is that physics discovers the constraints on consciousness, so that the laws/constraints of physics are co-fundamental with consciousness. Here is an Insight that contains this idea.

 

[Fra]

If you're talking about neutral monism, the view is that physics discovers the constraints on consciousness, so that the laws/constraints of physics are co-fundamental with consciousness. Here is an Insight that contains this idea.

I will give it another try. I started reading on your writings on this in the other thread, but lost interest a bit as i couldn't figure out what the objective was. Are you after the hard problem, or are you looking to solve open issues in physics. There was too much talk about humans mind that sort of confused me. I totally understand that if you look at the _abstractions_ "mind" "observer state" etc are similar. But the question is if that is what you mean, or if the focus is seriously on human mind and the more "spiritual issues"?

/Fredirk

 

[RUTA]

I will give it another try. I started reading on your writings on this in the other thread, but lost interest a bit as i couldn't figure out what the objective was. Are you after the hard problem, or are you looking to solve open issues in physics. There was too much talk about humans mind that sort of confused me. I totally understand that if you look at the _abstractions_ "mind" "observer state" etc are similar. But the question is if that is what you mean, or if the focus is seriously on human mind and the more "spiritual issues"?

/Fredirk

It has nothing to do with "spiritual issues". The Entropy paper was spawned from a conference at Oxford on mathematical physics models of consciousness. So, in that context the hard problem was key. But, the motivation from a physics standpoint is shown in Section 3 Neutral Monism and the Axioms of Physics. Also, we now have a principle account of the kinematics of QM (qubit Hilbert space structure) based on the same principle as SR (no preferred reference frame) here and here. So, this marriage helps complete this principle approach to physics.

 

[EPR]

Wrt to the Hard Problem, I thought Neutral Monism entailed the belief that everything in reality is made of just 1 substance. But this substance is neither matter not mind.
So it seems it must be something else and I assume it gives rise to the former 2?
Is it close?
Perhaps a Grand Master field that unifies all known forces at ultra high energies? Or did I misunderstand?

 

[AlexCaledin]

this substance is neither matter not mind.

Then, it's computer software! Every tech guy knows that

 

[RUTA]

Wrt to the Hard Problem, I thought Neutral Monism entailed the belief that everything in reality is made of just 1 substance. But this substance is neither matter not mind.
So it seems it must be something else and I assume it gives rise to the former 2?
Is it close?
Perhaps a Grand Master field that unifies all known forces at ultra high energies? Or did I misunderstand?

The philosopher wrote at length about that in our paper, I'm just the physicist :-) I have a simple analogy for how "mind" and "matter" are related to Neutral Pure Presence (NPP), but it's just an analogy. Inside a block of wood you have the bust of Einstein, the Venus de Milo, Teenage Mutant Ninja Turtles, etc. No one has to actually carve the block, all the figures are in there. The combination of experience ("mind") and its constraints (per physics, "matter") that represents our reality is just one of the possible "figures" in NPP. As the physicist, my job is to search for those constraints. The two fundamental constraints for physics as a whole as it currently stands are the boundary of a boundary principle and the relativity principle. That's explained in Section 3 of the paper.

 

[Fra]

It has nothing to do with "spiritual issues". The Entropy paper was spawned from a conference at Oxford on mathematical physics models of consciousness. So, in that context the hard problem was key. But, the motivation from a physics standpoint is shown in Section 3 Neutral Monism and the Axioms of Physics. Also, we now have a principle account of the kinematics of QM (qubit Hilbert space structure) based on the same principle as SR (no preferred reference frame) here and here. So, this marriage helps complete this principle approach to physics.

Hmm, part of this maybe due to terminology issues. I thought I understood first, but then all the talk about the mind gave me doubts... I am interested in the "constructing the laws of physics" part, I am not sure I even consider the "hard problem of consciousness" a scientific problem in the way it's usually defined. They way i MIGHT make sense out of the QUEST is to associate cosciousness with say "free will", but defined in terms of apparent "freedom of action" relative to other views. But this is not how "hard problem of consciousness" is defined if you just google it. Also I am not trained in these human philosophies in this sense. My philosophical part is mainly about philosophy of science and scientific method.

Do I understand you right, if i briefly summarize your points or your radical empirism like this?

1) "axiom 1" - What we have at hand, are a diversity of possible "VIEWS", which we may related to frames or observers etc. And we can only compare views by comparing them among each other (ie physical interactions?? this is what you call interacting bodily experiences? Ie. the central topic here is not the views themselves, but their interrelations.

2) "axiom 2" - no preferred view - this implies the constraint part (ie symmetry constraints on the class of all views, which has been the core constructing principle of physical law so far). Ie this constraints the POSSIBLE VIEWS, in the class. the constrains are also associated to physical law?

So 2 puts constraints on 1.

3) Then you argue that these two does NOT negate the existence of an experienced moment of Now, for each of the views? (ie block universe does not imply elimination of time?)

Before I comment more, let's see if I am off chart here or if this is approximately what you mean?

/Fredrik

 

[Fra]

A couple of checks, what is your take on these two quotes from one of the links in your insight on an interview with Christopher Fuchs (Qbist):

" So how will the QBism story end? Ultimately, Fuchs wants to answer a single question, one famously asked by the eminent physicist John Archibald Wheeler, who was Fuchs’ mentor: Why the quantum? That is, why should the world be built in such a way that it can only be described by the strange Rules of Quantum Mechanics? "
-- https://www.quantamagazine.org/quantum-bayesianism-explained-by-its-founder-20150604/"So eventually objectivity comes in?

I hope it does. Ultimately I view QBism as a quest to point to something in the world and say, that’s intrinsic to the world. But I don’t have a conclusive answer yet. Quantum mechanics is a single-user theory, but by dissecting it, you can learn something about the world that all of us are immersed in.

Treating quantum mechanics as a single-user theory resolves a lot of the paradoxes, like spooky action at a distance.

Yes, but in a way that a lot of people find troubling. The usual story of Bell’s theorem is that it tells us the world must be nonlocal. That there really is spooky action at a distance. So they solved one mystery by adding a pretty damn big mystery! What is this nonlocality? Give me a full theory of it. My fellow QBists and I instead think that what Bell’s theorem really indicates is that the outcomes of measurements are experiences, not revelations of something that’s already there. Of course others think that we gave up on science as a discipline, because we talk about subjective degrees of belief. But we think it solves all of the foundational conundrums. The only thing it doesn’t solve is Wheeler’s question, why the quantum?"
-- https://www.quantamagazine.org/quantum-bayesianism-explained-by-its-founder-20150604/

a lot of this - to me - gives me Carlo Rovelli flashbacks! And I suspect my critique against this is similar. It indeed boils down to "why the quantum", because this is the one weak link in Rovellis RQM as well.

Im curious if RUTAs reasoning is in line with Fuchs or not, and what is your take on the "why the quantum", do you agree it's a key question?

/Fredrik

 

[EPR]

Well, it's also subject to classical laws of motion, which an electron isn't. The bicycle is only subject to QM in such a way that the quantum mechanical effects are washed out and undetectable. For example, it cannot tunnel out of my shed - no matter how much you insist it is QM in nature. It's not that we are blind to the tunneling of bikes out of sheds, it's that bikes don't tunnel like electrons.

This is a difference: you cannot ascribe all electron-like properties to a bicycle. Nor vice versa.

And, in the same way that the atom is not a miniature solar system, the solar system is not a giant atom!

Good point but are your bike's quantum constituents there when they are not being observed/measured?
I understand your common-sense philosophy but not everyone agrees with its conclusions. It's too early to tell.
You cannot ascribe classical properties to the quantum constituents of your bike because ... well, they aren't very classical ;).

Its constituents atoms are presently best described as clouds of probabilities.

 

[PeroK]

Good point but are your bike's quantum constituents there when they are not being observed/measured?

Yes, they exist, but they do not individually have a well-defined position; collectively, however, a well-defined position can be ascribed in a scientifically meaningful way - using classical mechanics.

I understand your common-sense philosophy but not everyone agrees with its conclusions.

It's not common-sense philosophy. It's a point of view that QM does not have a monopoly on scientifically meaningful statements. And, yes, I know not everyone agrees with this.

For example, the previous quotation I included about the human heart is saying something about an organ of the human body. That statement is not precise in the way that a statement about an isolated QM system would be precise. Nonetheless, I claim it is scientifically meaningful.

 

[EPR]

The philosopher wrote at length about that in our paper, I'm just the physicist :-) I have a simple analogy for how "mind" and "matter" are related to Neutral Pure Presence (NPP), but it's just an analogy. Inside a block of wood you have the bust of Einstein, the Venus de Milo, Teenage Mutant Ninja Turtles, etc. No one has to actually carve the block, all the figures are in there. The combination of experience ("mind") and its constraints (per physics, "matter") that represents our reality is just one of the possible "figures" in NPP. As the physicist, my job is to search for those constraints. The two fundamental constraints for physics as a whole as it currently stands are the boundary of a boundary principle and the relativity principle. That's explained in Section 3 of the paper.

It's a bit over my head, but if i understand correctly, roughly speaking, in the middle of mind and matter sits awareness(NPP). And 'matter'(physics) constrains(shapes?) the experience(mind).

 

[WernerQH]

Now read Section 4 of this paper: https://www.mdpi.com/1099-4300/23/1/114/htm

Thank you for the reference. Most of the philosophical terminology is way above my head. But I agree with what I interpret as their central message: We should forgo "explaining" the EPR correlations and put up with describing correlations between events. I'm not sure if I can translate "multiscale contextuality" as "patterns of events in space-time". Anyway, I don't think this is something that physicists should leave to philosophers.

Most physicists can probably agree on the following realist description of the Aspect et al. experiments: electrons in a calcium atom do some "wiggling", and a few meters away, a few nanoseconds later, electrons in the detectors do some similar wiggling. It seems compelling to explain the observed correlations with photons carrying information from the source to the detectors. But, as the experiments show, this explanation raises more questions than it answers. Whatever travels between source and detectors appears to engage in superluminal communication. And these quantum objects don't seem to have "properties" in the usual sense. I think the only way out of this is to discard the notion of "photon" as an object that exists continuously from the time of its emission to the time of its absorption. A minimalist description of the experiment would talk of photons only as pairs of emission and absorption events.

Similarly, it is just a habit of thought that an electron has an existence continuous in time. On the zeptosecond scale the "world line" of an electron (an idea that already Heisenberg rejected) could dissolve into a series of points in space-time. Moreover, the possibility of gauge transformations indicates that photons and electrons do not exist independently. What is real could be just their interactions at definite points in space-time. QED is a theory describing the statistical correlations of these points, and "photon" and "electron" are just names we give to special patterns of events.

Not only does this picture provide a natural synthesis of the wave and particle concepts (which are just different arrangements of large numbers of events in space-time), but it also helps to understand that photons and electrons are identical. If there really were lines connecting the interaction points, as the Feynman diagrams suggest, Nature would always "know" which electron interacted with which photon. However, the rules say that the points must be connected in all possible legal ways, and the contributions of the different diagrams added. I should add immediately that it is not sufficient to consider only the amplitudes in the forward time-direction, but also the backward time-direction needs to be included, as is done in the Schwinger-Keldysh closed time-path formalism. In QED, each event is characterized not only by its space and time coordinates, but also by a phase factor (a la Kaluza/Klein) and a tag identifying it as belonging to the forward or backward time branch (assuming that events always occur in close pairs on both branches). Quantum field theory is just a machinery for calculating correlation functions.

The philosophical guideline that the EPR experiments and the QED formalism seem to suggest is: Atomism must be extended from space to space-time.

 

[atyy]

What does "it" refer to?

The ether.

 

[martinbn]

Or perhaps it will be as ridiculous as the cosmological constant, which Einstein thought was his biggest mistake.

The ether.

So you were saying

Or perhaps the ether will be as ridiculous as the cosmological constant, which Einstein thought was his biggest mistake.

What do you mean by that?

Anyway the Noether theorem proves that there is no ether

 

[atyy]

Anyway the Noether theorem proves that there is no ether

But it allows an aether.

 

[Demystifier]

The ether.

Are you suggesting that eventually it will turn out that there is ether after all?

 

[atyy]

Are you suggesting that eventually it will turn out that there is ether after all?

Of course.

 

[PeterDonis]

the possibility of gauge transformations indicates that photons and electrons do not exist independently.

I don't follow this particular point. Are you saying that in a theory that didn't have such gauge transformations, we would have to treat the particles as existing independently? Why? It seems to me that the viewpoint you describe in your next few sentences...

What is real could be just their interactions at definite points in space-time. QED is a theory describing the statistical correlations of these points, and "photon" and "electron" are just names we give to special patterns of events.

...would work for any particles, whether the theory that described them had gauge transformations or not.

 

[RUTA]

Hmm, part of this maybe due to terminology issues. I thought I understood first, but then all the talk about the mind gave me doubts... I am interested in the "constructing the laws of physics" part, I am not sure I even consider the "hard problem of consciousness" a scientific problem in the way it's usually defined. They way i MIGHT make sense out of the QUEST is to associate cosciousness with say "free will", but defined in terms of apparent "freedom of action" relative to other views. But this is not how "hard problem of consciousness" is defined if you just google it. Also I am not trained in these human philosophies in this sense. My philosophical part is mainly about philosophy of science and scientific method.

Do I understand you right, if i briefly summarize your points or your radical empirism like this?

1) "axiom 1" - What we have at hand, are a diversity of possible "VIEWS", which we may related to frames or observers etc. And we can only compare views by comparing them among each other (ie physical interactions?? this is what you call interacting bodily experiences? Ie. the central topic here is not the views themselves, but their interrelations.

2) "axiom 2" - no preferred view - this implies the constraint part (ie symmetry constraints on the class of all views, which has been the core constructing principle of physical law so far). Ie this constraints the POSSIBLE VIEWS, in the class. the constrains are also associated to physical law?

So 2 puts constraints on 1.

3) Then you argue that these two does NOT negate the existence of an experienced moment of Now, for each of the views? (ie block universe does not imply elimination of time?)

Before I comment more, let's see if I am off chart here or if this is approximately what you mean?

/Fredrik

Yes, as you point out, Einstein's "real external world" aka "physical reality" aka "objective reality" is modeled by POSSIBLE VIEWS aka perspectives. This model is constructed by reconciling ACTUAL VIEWS (empiricism) according to the constraints of physics, e.g., no preferred view (POSSIBLE or ACTUAL). As of now, that model strongly suggests the block universe, but that model does not in any way contradict or negate our dynamical experience of time (as I explained in this Insight).

 

[RUTA]

A couple of checks, what is your take on these two quotes from one of the links in your insight on an interview with Christopher Fuchs (Qbist):

" So how will the QBism story end? Ultimately, Fuchs wants to answer a single question, one famously asked by the eminent physicist John Archibald Wheeler, who was Fuchs’ mentor: Why the quantum? That is, why should the world be built in such a way that it can only be described by the strange Rules of Quantum Mechanics? "
-- https://www.quantamagazine.org/quantum-bayesianism-explained-by-its-founder-20150604/"So eventually objectivity comes in?

I hope it does. Ultimately I view QBism as a quest to point to something in the world and say, that’s intrinsic to the world. But I don’t have a conclusive answer yet. Quantum mechanics is a single-user theory, but by dissecting it, you can learn something about the world that all of us are immersed in.

Treating quantum mechanics as a single-user theory resolves a lot of the paradoxes, like spooky action at a distance.

Yes, but in a way that a lot of people find troubling. The usual story of Bell’s theorem is that it tells us the world must be nonlocal. That there really is spooky action at a distance. So they solved one mystery by adding a pretty damn big mystery! What is this nonlocality? Give me a full theory of it. My fellow QBists and I instead think that what Bell’s theorem really indicates is that the outcomes of measurements are experiences, not revelations of something that’s already there. Of course others think that we gave up on science as a discipline, because we talk about subjective degrees of belief. But we think it solves all of the foundational conundrums. The only thing it doesn’t solve is Wheeler’s question, why the quantum?"
-- https://www.quantamagazine.org/quantum-bayesianism-explained-by-its-founder-20150604/

a lot of this - to me - gives me Carlo Rovelli flashbacks! And I suspect my critique against this is similar. It indeed boils down to "why the quantum", because this is the one weak link in Rovellis RQM as well.

Im curious if RUTAs reasoning is in line with Fuchs or not, and what is your take on the "why the quantum", do you agree it's a key question?

/Fredrik

I don't buy the "single-user theory" idea at all. How do you obtain a theory in the first place if not by corroborated empiricism? Everything in our papers cited earlier is based on the existence of an unambiguous objective reality constructed coherently via empiricism.

As we explained in our papers, we can now understand the kinematic structure of QM (qubit Hilbert space structure, whence quantum entanglement) to follow from the relativity principle, just like the kinematic structure of SR (Minkowski spacetime structure, whence time dilation and length contraction). SR obtains by applying the relativity principle to the measurement of c while QM obtains by applying the relativity principle to the measurement of h. We then explain how this immediately answers "why the quantum?" and dictates the ineluctably probabilistic nature of QM. None of this is interpretation dependent, it all follows from empirical and mathematical facts, i.e., it is a "principle" account of QM per Einstein's terminology. Thus, looking for a "constructive" account of quantum entanglement per causal mechanisms is precisely analogous to looking for a "constructive" account of time dilation and length contraction per the luminiferous ether.

 

[WernerQH]

Are you saying that in a theory that didn't have such gauge transformations, we would have to treat the particles as existing independently?

No, I meant nothing of this sort. When I learned quantum theory I thought of electrons and photons as separate entities, and it struck me as odd that a change of perspective on the photon field should change the wave function of the electron. But this becomes easier to comprehend if one thinks of both fields as derived from a common underlying structure: a point process in a five-dimensional manifold.

 

[PeroK]

No, I meant nothing of this sort. When I learned quantum theory I thought of electrons and photons as separate entities, and it struck me as odd that a change of perspective on the photon field should change the wave function of the electron. But this becomes easier to comprehend if one thinks of both fields as derived from a common underlying structure: a point process in a five-dimensional manifold.

Do you mean this?

https://wp.towson.edu/5dstm/introduction/