I Relational Hidden Variables (Real ensemble or thermal?)

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Smolin latest book about the quantum is quite interesting. Its called "Einstein Unfinished Revolution: Search for What Lies Beyond the Quantum" and he has a new theory or interpretation. Id like to know what you make of it. The theory is very simple. Similar views produce QM. May i know how this differs to say Neumaier Thermal Interpretation? You can understand Neumaier's main idea only after reading pages and pages of advanced arxiv papers and i couldnt comprehend its basic thesis the whole year. Is it similar to Smolin's? Can anyone summarize it as i like Smolin ensemble formulation and wonder if Neumaier's is similar to it or how they differ? Smolin book has several hundred paragraphs so its justifed to share the following just so everyone gets the gist or main idea and hence can give feedback if it makes sense and what possible flaws. Thanks.

Now, for big, clunky things like ourselves, made up of vast numbers of atoms, this is as far as it goes. But consider what it takes for atoms to have similar views. Atoms have many fewer degrees of freedom, hence fewer relational properties. So atoms which are far away from each other in space may still have similar neighborhoods, just because there are vastly fewer configurations their local neighborhoods could take. This suggests that perhaps similar atoms, with the same constituents and similar surroundings, interact with each other just because they have similar views.

These interactions would be highly, highly nonlocal. But in my recent work, I have showed that this could be the basis of quantum physics. Consider a hydrogen atom in a water molecule dancing in the air in front of me. This has a first neighborhood consisting of an oxygen atom, and a second neighborhood consisting of the whole molecule. The same is true of every hydrogen atom in a water molecule everywhere in the universe. So I am going to trust my relational instincts and take the crazy step of positing that all these atoms are interacting with each other, just because their views are similar. More specifically, I will posit that the interactions act to increase the differences between these atoms’ views. This will go on until the system has maximized the variety of views the atoms have of the universe.

In a recent paper, I showed that the hypothesis of maximal variety leads to the Schrödinger equation, and hence to quantum mechanics. This happens because there turns out to be a mathematical similarity between the variety and Bohm’s quantum force. As a result, Bohm’s quantum force acts to increase the variety of a system. It does so by making the neighborhoods of all the different particles as different from each other as possible.

In this approach the probabilities in quantum mechanics refer to an ensemble that really exists, the ensemble of all systems with similar views. This is a real ensemble, in that the elements are not located in our imagination; they are, each and every one, a part of the natural world. This is in accord with the principles of causal completeness and reciprocity.

This was the basis of a relational hidden variable theory I proposed, which I called the real ensemble formulation of quantum mechanics. From it, I could derive the Schrödinger formulation of quantum mechanics from a principle that maximizes the variety present in real ensembles of systems with similar views of the universe.
 

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You can understand Neumaier's main idea only after reading pages and pages of advanced arxiv papers and i couldnt comprehend its basic thesis the whole year.
DarMM gave in post #268 of the main thread on the thermal interpretation a nice summary of it. Post #484 is my very short summary.
Smolin ensemble formulation and wonder if Neumaier's is similar to it or how they differ?
Not similar. The thermal interpretation is deterministic, not an ensemble interpretation. The stochastic features arise as effects of the neglected environment.
 
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DarMM gave in post #268 of the main thread on the thermal interpretation a nice summary of it. Post #484 is my very short summary.

Not similar. The thermal interpretation is deterministic, not an ensemble interpretation. The stochastic features arise as effects of the neglected environment.
But that is exactly Smolin theory that the stochastic features arise as effects of the neglected environment! I think you have the same theory, only yours is a Qft completion. I hope you can articulate it to general audience so many can understand. You can't finish one paragraph using using very difficult terms. I think you can write like Smolin so the rest can understand too.

The following is critical Smolin passages and wont quote other paragraphs again. So please bear with me:

"On the technical side, this theory borrows from the many interacting classical universes theory I described in the last chapter, only the ensemble of similar systems does not come from other universes parallel to our own; instead they are similar systems far away in distant regions of our own single universe.

In this theory, the phenomena of quantum physics arise from a continual interplay between the similar systems that make up an ensemble. The partners of an atom in my glass of water are spread through the universe. The indeterminism and uncertainties of quantum physics arise from the fact that we cannot control or observe those different systems. In this picture, an atom is quantum because it has many nearly identical copies of itself, spread through the universe.

An atom with its neighborhood has many copies because it is close to the smallest possible scale. It is simple to describe, as it has few degrees of freedom. In a big universe it will have many near copies.

Large, macroscopic systems such as cats, machines, or ourselves have, by contrast, a vast complexity, which takes a great deal of information to describe. Even in a very big universe, such systems have no close or exact copies. Hence, cats and machines and you and I are not part of any ensemble. We are singletons, with nothing similar enough to interact with through the nonlocal interactions. Hence we do not experience quantum randomness. This is a solution to the measurement problem."
 

A. Neumaier

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Hence, cats and machines and you and I are not part of any ensemble. We are singletons, with nothing similar enough to interact with through the nonlocal interactions. Hence we do not experience quantum randomness. This is a solution to the measurement problem.
The explanation of the ''Hence'' would be a solution to the measurement problem. But an ensemble theory cannot explain any property of singletons - precisely this is the measurement problem! The state of a cat cannot have the interpretation written down in the standard postulates of QM. And given only these foundations, nothing can....
 

A. Neumaier

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Smolin latest book about the quantum is quite interesting. Its called "Einstein Unfinished Revolution: Search for What Lies Beyond the Quantum" and he has a new theory or interpretation.
Lee Smolin said:
In a recent paper, I showed that the hypothesis of maximal variety leads to the Schrödinger equation, and hence to quantum mechanics.
See Quantum mechanics and the principle of maximal variety.
 
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In this theory, the phenomena of quantum physics arise from a continual interplay between the similar systems that make up an ensemble
Similarlty in https://arxiv.org/abs/1104.2822 Smolin says:

"Microscopic systems have indefinite values of beables, while macroscopic systems have definite values, because microscopic systems come in many copies, and so are subject to the copy rule, in which they evolve stochastically by copying the beables of members of the ensemble they share. Macroscopic systems are those that have no copies, anywhere in the universe, hence they are not subject to the copy dynamics."

I think this is trivially inconsistent with QM. We have done interference experiments with large proteins and crystals, and it would be possible to make an experiment where each molecule (of similar mass and size) was internally structurally unique in the experiment., Following QM, we will still expect to see aggregate quantum interference effects over the center of mass measurement, despite Smolin's copy rule not applying. Probably the completed protein interference experiments already had a bunch of this variation due to experimental error.

This whole idea also seems to require a very strict, fundamental particle ontology to even be meaningfully discussed, which is inconsistent with Haag's theorem/interacting QFTs. I cannot see how this distinction of unique/non-unique systems could even get off the ground in a theory fields from which particles are emergent in finite regimes (this being our best concept of physical reality as it stands).
 
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Similarlty in https://arxiv.org/abs/1104.2822 Smolin says:

"Microscopic systems have indefinite values of beables, while macroscopic systems have definite values, because microscopic systems come in many copies, and so are subject to the copy rule, in which they evolve stochastically by copying the beables of members of the ensemble they share. Macroscopic systems are those that have no copies, anywhere in the universe, hence they are not subject to the copy dynamics."

I think this is trivially inconsistent with QM. We have done interference experiments with large proteins and crystals, and it would be possible to make an experiment where each molecule (of similar mass and size) was internally structurally unique in the experiment., Following QM, we will still expect to see aggregate quantum interference effects over the center of mass measurement, despite Smolin's copy rule not applying. Probably the completed protein interference experiments already had a bunch of this variation due to experimental error.

This whole idea also seems to require a very strict, fundamental particle ontology to even be meaningfully discussed, which is inconsistent with Haag's theorem/interacting QFTs. I cannot see how this distinction of unique/non-unique systems could even get off the ground in a theory fields from which particles are emergent in finite regimes (this being our best concept of physical reality as it stands).
Wasn't Smolin aware of the experiments with large proteins and crystals or what was his counterarguments?

Are you familiar with Neumaier Thermal Interpretation? Using your own words, can you summarize it using plain english like how Smolin wrote in his book? Neumaier's is the most difficult to understand because his target are all Ph.Ds. So please bring the language down to us at least undergraduates or general book readers. I'm aware of QFT. Was Neumaier arguing that since QM is just effective theory of QFT. The measurement problem vanishes in QFT? But I'm aware it is still the same in QFT. So how does Neumaier solve it? His reasoning seems to be a cat couldn't be described using QM because of fields. Was he arguing there were no particles so measurement problem solved? Kindly briefly give the gist of it in book level approach akin to Smolin book. I like Smolin explanation because there is the elegance to it. I wanna understand Neumaier's basic ideas too to see similarities and differences to Smolin's. So share it using your own words. Imagine you are addressing it to Smolin book readers. Thank you!
 
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Wasn't Smolin aware of the experiments with large proteins and crystals or what was his counterarguments?
I hadn't looked at the 2015 paper above when I commented, but in section 4 there he does mention he thinks that, in an experiment generally along these lines, his theory would predict a departure from regular QM. But he doesn't mention what he has to say about the existing organic molecule experiments, and I think these (or small variations of them) already show the ship has sailed on his proposal. But I haven't read his book or all his papers, so I don't know if he tackles this directly somewhere else.

Are you familiar with Neumaier Thermal Interpretation? Using your own words, can you summarize it using plain english like how Smolin wrote in his book? Neumaier's is the most difficult to understand because his target are all Ph.Ds. So please bring the language down to us at least undergraduates or general book readers. I'm aware of QFT. Was Neumaier arguing that since QM is just effective theory of QFT. The measurement problem vanishes in QFT? But I'm aware it is still the same in QFT. So how does Neumaier solve it? His reasoning seems to be a cat couldn't be described using QM because of fields. Was he arguing there were no particles so measurement problem solved? Kindly briefly give the gist of it in book level approach akin to Smolin book. I like Smolin explanation because there is the elegance to it. I wanna understand Neumaier's basic ideas too to see similarities and differences to Smolin's. So share it using your own words. Imagine you are addressing it to Smolin book readers. Thank you!
I don't really agree that the standard for an interpretation of QM is that it can be described at a popsci level or understandable at a popsci level. My experience is that popsci readers never really understand any interpretation accurately - this goes for Copenhagen, many worlds, Bohm, etc. - and always have a lingering confusion or believe something impossible. I actually think its malpractice for a popsci book or blog to argue on behalf or against any interpretation. Books like this should just try to describe pros and cons of each major option, very neutrally. This is extra true for an idea like Smolin's which predicts deviations from standard QM. A general audience reader won't appreciate how big of a claim this is, and how it really requires extraordinary evidence to ever be accepted.
 
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Smolin reasoned there were 3 kinds of anti-realists:

1. radical anti-realists
2. quantum epistemologists
3. operationalists

There are two kinds of realists.
1. Naive realists
2. Magical realists.

Both answered yes to these two questions:

"First off, does the natural world exist independently of our minds? More precisely, does matter have a stable set of properties in and of itself, without regard to our perceptions and knowledge?

Second, can those properties be comprehended and described by us? Can we understand enough about the laws of nature to explain the history of our universe and predict its future?"

I read the book two times and very familiar with all the arguments. I just want to know updates of Smolin own realist theory. Second. I want to know where Neumaier belonged to. He is a Witten that we can actually talk too and not inaccessible worlds away. I guess Neumaier is a realist? Is there no experiments that can test Neumaier theory? (I know all interpretations have same math but remember different intepretations have extra math that only future experiments can prove).

I hope all can read Smolin book. The following is from the preface and free at amazon. So let it introduce the best QM book on the planet that introduces the measurement problem. It is one of a kind book. I request Neumaier to write like it too.

THERE ARE DIFFERENT KINDS of anti-realists, which leads to different views on quantum mechanics.

Some anti-realists believe that the properties we ascribe to atoms and elementary particles are not inherent in those objects, but are created only by our interactions with them, and exist only at the time when we measure them. We can call these radical anti-realists. The most influential of these was Niels Bohr. He was the first to apply quantum theory to the atom, after which he became the leader and mentor to the next generation of quantum revolutionaries. His radical anti-realism colored much of how quantum theory came to be understood.

Another group of anti-realists believes that science, as a whole, does not deal in or talk about what is real in nature, but rather only ever talks about our knowledge of the world. In their view, the properties physics ascribes to an atom are not about that atom; they are instead only about the knowledge we have of the atom. These scientists can be called quantum epistemologists.

And then there are the operationalists, a group of anti-realists who are agnostic about whether there is a fundamental reality independent of us or not. Quantum mechanics, they argue, is not in any case about reality; it is rather a set of procedures for interrogating atoms. It is not about the atoms themselves; it is about what happens when atoms come into contact with the big devices we use to measure them. Heisenberg, the best of Bohr’s protégés, who invented the equations of quantum mechanics, was, at least partly, an operationalist.

In contrast to the disputes between radical anti-realists, quantum epistemologists, and operationalists, all realists share a similar perspective—we agree about the answer to both questions I posed above. But we differ on how we answer a third question: Does the natural world consist mainly of the kinds of objects that we see when we look around ourselves, and the things that constitute them? In other words, is what we see when we look around typical of the universe as a whole?

Those of us who say yes to this question can call ourselves simple or naive realists. I should alert the reader that I use the adjective “naive” to mean strong, fresh, uncomplicated. For me, a view is naive if it is not in need of sophisticated arguments or convoluted justifications. I would argue that a naive realism is, whenever possible, to be preferred.

There are realists who are not naive in this sense. They believe that reality is vastly different from the world we perceive and measure.

An example of such a view is the Many Worlds Interpretation, which teaches that the world we perceive is only one of a vast and ever-growing number of parallel worlds. Its proponents call themselves realists, and they have some claim to that designation by virtue of their answering yes to the first two questions. But, in my opinion, they are realists only in the most technical, academic sense. They may perhaps be called magical realists, for they believe that what is real is far beyond the world we perceive. Magical realism in this sense is almost a form of mysticism, for it implies that the true world is hidden from our perception.
 

zonde

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I think this is trivially inconsistent with QM. We have done interference experiments with large proteins and crystals, and it would be possible to make an experiment where each molecule (of similar mass and size) was internally structurally unique in the experiment., Following QM, we will still expect to see aggregate quantum interference effects over the center of mass measurement, despite Smolin's copy rule not applying. Probably the completed protein interference experiments already had a bunch of this variation due to experimental error.
So, you are saying QM predicts interference for distinguishable systems. Well, this is just plain wrong.
 
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So, you are saying QM predicts interference for distinguishable systems. Well, this is just plain wrong.
No I'm not saying that. The interference at issue is internal to the system, not between the systems. Suppose you have a "universal" closed MZI which can do an interference experiment on any particle, atom, or molecule you want - from an electron to a DNA helix - and suppose it is tuned to constructive (destructive) interference in exit port 1 (2). Now you take any random bucket of particles, atoms, and molecules and send systems through the MZI one by one. You will get 100% clicks at port 1, per QM. Smolin is saying there's no QM, but instead this other theory where at some point the molecules get so complex they just won't interfere *in principle*. So, Smolin predicts some molecules click at port 2, and QM says this never happens.

Problem for Smolin is we've confirmed analogous QM interference effects already for some quite complex molecules.
 
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we've confirmed analogous QM interference effects already for some quite complex molecules
Yes, using diffraction gratings, as for example in this experiment with buckyballs:


Note, however, that diffraction gratings are not the same as beam splitters. AFAIK we have nothing analogous to beam splitters, which are essential components of an MZI, for anything other than photons.

Another interesting observation is in section III.B of the above linked paper, which discusses coherence and which path information. The paper notes that the buckyballs can emit radiation during the experiment (because, unlike simpler particles, they have a rich array of excited states and are highly unlikely to be in the ground state when prepared), but that the radiation is weak enough that it does interact significantly with the environment and so does not constitute which path information. But as the objects in such an experiment get more and more complex, it would be more and more likely that enough radiation would be emitted to interact significantly with the environment and therefore provide which path information, destroying the interference.

A mechanism like this could lead to large enough objects not showing quantum interference effects no matter how hard we try, even though this is not "in principle" (you could still theoretically control the preparation process enough to ensure that the objects were all in the ground state and could not emit radiation, but it's not possible in practice). So even if Smolin's empirical claim turned out to be true for large enough molecules (no observed interference no matter how hard we try), it might not establish that his underlying theoretical claim (QM is incomplete) is correct.
 
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Note, however, that diffraction gratings are not the same as beam splitters. AFAIK we have nothing analogous to beam splitters, which are essential components of an MZI, for anything other than photons.
Yes of course - I was just abstracting for (I hoped) clarity. Its the same premise with diffraction.

A mechanism like this could lead to large enough objects not showing quantum interference effects no matter how hard we try, even though this is not "in principle" (you could still theoretically control the preparation process enough to ensure that the objects were all in the ground state and could not emit radiation, but it's not possible in practice). So even if Smolin's empirical claim turned out to be true for large enough molecules (no observed interference no matter how hard we try), it might not establish that his underlying theoretical claim (QM is incomplete) is correct.
Right, this is important. As you say, at a certain point, QM also predicts interference experiments will fail, but in QM this is due to unavoidable decoherence effects. This means the classical limit only seems like evidence for Smolin's proposal because he misattributes the effect to uniqueness/complexity, when really it is just that larger systems decohere more easily, and also can obviously be more complex. It's like the mistake of saying ice cream causes drowning deaths when really people just separately both get ice cream and go swimming on hot days.

The other problem for Smolin is we actually have pretty good control over decoherence for some pretty intricate molecules, which produces a testable regime where Smolin and QM explicitly will disagree. For the record, the real experiment I am thinking off is: https://www.nature.com/articles/ncomms1263

"Our experiments prove the quantum wave nature and delocalization of compounds composed of up to 430 atoms, with a maximal size of up to 60 Å, masses up to m=6,910 AMU and de Broglie wavelengths down to λdB=h/mv≃1 pm. We show that even complex systems, with more than 1,000 internal degrees of freedom, can be prepared in quantum states that are sufficiently well isolated from their environment to avoid decoherence and to show almost perfect coherence."

The proposal here goes even further: https://iopscience.iop.org/article/10.1088/0031-8949/91/6/063007. And there has even been talk of interference with full viruses. Frankly, I'd be shocked if these interference experiments failed, when decoherence is under control.
 
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Yes of course - I was just abstracting for (I hoped) clarity. Its the same premise with diffraction.



Right, this is important. As you say, at a certain point, QM also predicts interference experiments will fail, but in QM this is due to unavoidable decoherence effects. This means the classical limit only seems like evidence for Smolin's proposal because he misattributes the effect to uniqueness/complexity, when really it is just that larger systems decohere more easily, and also can obviously be more complex. It's like the mistake of saying ice cream causes drowning deaths when really people just separately both get ice cream and go swimming on hot days.

The other problem for Smolin is we actually have pretty good control over decoherence for some pretty intricate molecules, which produces a testable regime where Smolin and QM explicitly will disagree. For the record, the real experiment I am thinking off is: https://www.nature.com/articles/ncomms1263

"Our experiments prove the quantum wave nature and delocalization of compounds composed of up to 430 atoms, with a maximal size of up to 60 Å, masses up to m=6,910 AMU and de Broglie wavelengths down to λdB=h/mv≃1 pm. We show that even complex systems, with more than 1,000 internal degrees of freedom, can be prepared in quantum states that are sufficiently well isolated from their environment to avoid decoherence and to show almost perfect coherence."

The proposal here goes even further: https://iopscience.iop.org/article/10.1088/0031-8949/91/6/063007. And there has even been talk of interference with full viruses. Frankly, I'd be shocked if these interference experiments failed, when decoherence is under control.
Smolin mentioned quantum computer can test his theory, not protein or buckyball. Does anyone know how to implement it? Smolin interpretation is so superior because its background independent unlike rest of interpretations which have fixed background.

Smolin briefly described quantum computer. But how can two quantum computers interfere?

"I argued that large complex systems have no copies, and hence are not subject to quantum randomness. But can we produce microscopic systems, made from a small number of atoms, which also have no copies anywhere in the universe? Such systems would not obey quantum mechanics, in spite of being microscopic.

We have the capability to do just that using the tools of quantum information theory. Indeed, a sufficiently large quantum computer should be able to produce states involving enough entangled qubits that they are very unlikely to have any natural copies anywhere in the observable universe. This suggests that the real ensemble theory can be falsified by making a large quantum computer that works exactly as predicted by quantum mechanics."
 

zonde

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No I'm not saying that. The interference at issue is internal to the system, not between the systems. Suppose you have a "universal" closed MZI which can do an interference experiment on any particle, atom, or molecule you want - from an electron to a DNA helix - and suppose it is tuned to constructive (destructive) interference in exit port 1 (2). Now you take any random bucket of particles, atoms, and molecules and send systems through the MZI one by one. You will get 100% clicks at port 1, per QM. Smolin is saying there's no QM, but instead this other theory where at some point the molecules get so complex they just won't interfere *in principle*. So, Smolin predicts some molecules click at port 2, and QM says this never happens.

Problem for Smolin is we've confirmed analogous QM interference effects already for some quite complex molecules.
Yes, you made a point. Many different particles with (nearly) identical mass and momentum undergoing self interference in the same setup will contribute to the same interference pattern according to QM.

But even so I agree that Smolin's idea is quite problematic, I'm not sure your argument is correct that the experiment you gave falsifies Smolin's idea. Smolin does not say that complex molecules can't show interference, he says that unique molecules can't show interference. And of course molecules in the experiment are not unique. Experimenters needed quite a bunch of these molecules to perform their experiment.

As I understand Smolin explains interference as non-local interaction between identical systems. My problem with this explanation is - how other identical systems "know" about experimental setup?
Say this experiment with interference of helium atoms in MZ type setup with delayed choice manipulation:
Wheeler's delayed-choice gedanken experiment with a single atom
Fine, particles are identical, but there is single atom in each experimental run. Do atoms from other experimental runs "remember" the setup and pass this information to the particle that is now moving through the setup? This does not seem like serious explanation.
I consider physical ensembles an interesting idea, but if several particles have to pass the setup in order for interference to show up then the only viable option IMO would be to consider possibility that other particles leave the information about the path they traveled in environment. But as I understand Smolin's idea is different.
 

zonde

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Smolin mentioned quantum computer can test his theory, not protein or buckyball. Does anyone know how to implement it? Smolin interpretation is so superior because its background independent unlike rest of interpretations which have fixed background.

Smolin briefly described quantum computer. But how can two quantum computers interfere?

"I argued that large complex systems have no copies, and hence are not subject to quantum randomness. But can we produce microscopic systems, made from a small number of atoms, which also have no copies anywhere in the universe? Such systems would not obey quantum mechanics, in spite of being microscopic.

We have the capability to do just that using the tools of quantum information theory. Indeed, a sufficiently large quantum computer should be able to produce states involving enough entangled qubits that they are very unlikely to have any natural copies anywhere in the observable universe. This suggests that the real ensemble theory can be falsified by making a large quantum computer that works exactly as predicted by quantum mechanics."
It is more reasonable to thoroughly test any new idea against existing experimental results rather then developing new experiments. It is much cheaper and faster. You can eliminate a lot of ideas that does not work this way as we have plenty of experimental data.
 
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Yes, you made a point. Many different particles with (nearly) identical mass and momentum undergoing self interference in the same setup will contribute to the same interference pattern according to QM.

But even so I agree that Smolin's idea is quite problematic, I'm not sure your argument is correct that the experiment you gave falsifies Smolin's idea. Smolin does not say that complex molecules can't show interference, he says that unique molecules can't show interference. And of course molecules in the experiment are not unique. Experimenters needed quite a bunch of these molecules to perform their experiment.

As I understand Smolin explains interference as non-local interaction between identical systems. My problem with this explanation is - how other identical systems "know" about experimental setup?
Say this experiment with interference of helium atoms in MZ type setup with delayed choice manipulation:
Wheeler's delayed-choice gedanken experiment with a single atom
Fine, particles are identical, but there is single atom in each experimental run. Do atoms from other experimental runs "remember" the setup and pass this information to the particle that is now moving through the setup? This does not seem like serious explanation.
I consider physical ensembles an interesting idea, but if several particles have to pass the setup in order for interference to show up then the only viable option IMO would be to consider possibility that other particles leave the information about the path they traveled in environment. But as I understand Smolin's idea is different.
See this paper by Smolin. Its also mentioned in the book. https://arxiv.org/abs/1205.3707 part of the abstract reads:

"We also propose that laws of quantum evolution arise from a principle of precedence, according to which the outcome of a measurement on a quantum system is selected randomly from the ensemble of outcomes of previous instances of the same measurement on the same quantum system. This implies that dynamical laws for quantum systems can evolve as the universe evolves, because new precedents are generated by the formation of new entangled states."
 

A. Neumaier

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Smolin latest book about the quantum is quite interesting. Its called "Einstein Unfinished Revolution: Search for What Lies Beyond the Quantum" and he has a new theory or interpretation.
Lee Smolin said:
In a recent paper, I showed that the hypothesis of maximal variety leads to the Schrödinger equation, and hence to quantum mechanics.
I now read Smolin's Quantum mechanics and the principle of maximal variety, which contains the technical material. He proposes a theory with an ensemble of ##N## identically structured systems in a ##d##-dimensional multiparticle configuration space interacting with each other via a strange, messy multiparticle action (19), which is mathematically ill-defined since the complex logarithm is multivalued.

He shows that in the limit ##N\to\infty## and an associated continuum, the mean of the ##N## systems is the mean of a system determined by a Schrödinger equation (54), via an argument similar to Bohmian mechanics. The leading correction (32) to the limit is of order ##O(N^{2/d})## which goes exceedingly poorly to zero, making it likely that for reasonable ##N## the errors are always large.
The proposed experiments take small ##N## and assume these systems are actual multiparticle systems in traditional configuration space.

I don't think he actually showed anything like what he claimed, since the universe is a single system and not an ensemble of subsystems. The splitting into subsystems, which for Smolin is God-given and must be fixed to define the interaction, is arbitrary in our actual universe. Hence there is no way to test his theory.
Smolin interpretation is so superior because its background independent
Smolin's definitions are based on the Euclidean norm in configuration space, hence assume a flat background.
 
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A. Neumaier

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Smolin reasoned [...]

There are two kinds of realists.
1. Naive realists
2. Magical realists.

Both answered yes to these two questions:

"First off, does the natural world exist independently of our minds? More precisely, does matter have a stable set of properties in and of itself, without regard to our perceptions and knowledge?

Second, can those properties be comprehended and described by us? Can we understand enough about the laws of nature to explain the history of our universe and predict its future?"

I want to know where Neumaier belonged to.
Smolin's classification is too black and white.

According to the thermal interpretation of quantum physics, Nature existed before human minds existed, and had now and then objective properties comprehended and described locally by q-expectations of quantum fields and nonlocally by more complicated q-expectations. Perceptions and knowledge only provide approximations to these objective properties, more knowledgeable people having better approximations about aspects where they are knowledgeable.. We can explain part of the history and predict part of the future since our knowledge and understanding of the true state of the universe is limited.

In contrast to Smolin, the TI does not need to take any limits to recover the quantum laws, except to the extent it is needed to get standard quantum mechanics from standard quantum field theory.
 
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I now read Smolin's Quantum mechanics and the principle of maximal variety, which contains the technical material. He proposes a theory with an ensemble of ##N## identically structured systems in a ##d##-dimensional multiparticle configuration space interacting with each other via a strange, messy multiparticle action (19), which is mathematically ill-defined since the complex logarithm is multivalued.

He shows that in the limit ##N\to\infty## and an associated continuum, the mean of the ##N## systems is the mean of a system determined by a Schrödinger equation (54), via an argument similar to Bohmian mechanics. The leading correction (32) to the limit is of order ##O(N^{2/d})## which goes exceedingly poorly to zero, making it likely that for reasonable ##N## the errors are always large.
The proposed experiments take small ##N## and assume these systems are actual multiparticle systems in traditional configuration space.

I don't think he actually showed anything like what he claimed, since the universe is a single system and not an ensemble of subsystems. The splitting into subsystems, which for Smolin is God-given and must be fixed to define the interaction, is arbitrary in our actual universe. Hence there is no way to test his theory.

Smolin's definitions are based on the Euclidean norm in configuration space, hence assume a flat background.
It's related to Smolin idea that time is fundamental, space is emergent. Look. Smolin book has thousands of facts. It may be the greatest quantum book of the century for the masses ever. If you will google "Smolin realist vs antirealist". You will see many physicists read it. So hope you can read it too. The following is (I promise) the last passages (very critical) that I need to share so we can properly scrutinize whether time is really fundamental and space emergent. As his relational hidden variables is based on this:

(can anyone refute the following?)

This is as far as principles take us. The next step is to frame hypotheses. I propose three hypotheses about what lies beyond spacetime and beyond the quantum:

Time, in the sense of causation, is fundamental. This means the process by which future events are produced from present events, called causation, is fundamental.

Time is irreversible. The process by which future events are created from present events can’t go backward. Once an event has happened, it can’t be made to un-happen.*

Space is emergent. There is no space, fundamentally. There are events and they cause other events, so there are causal relations. These events make up a network of relationships. Space arises as a coarse-grained and approximate description of the network of relationships between events.

This means that locality is emergent. Nonlocality must then also be emergent.

If locality is not absolute, if it is the contingent result of dynamics, it will have defects and exceptions. And indeed, this appears to be the case: how else are we to understand quantum nonlocality, particularly nonlocal entanglement? These, I would hypothesize, are remnants of the spaceless relations inherent in the primordial stage, before space emerges. Thus, by positing that space is emergent we gain a possibility of explaining quantum nonlocality as a consequence of defects which arise in that emergence.2

The combination of a fundamental time and an emergent space implies that there may be a fundamental simultaneity. At a deeper level, in which space disappears but time persists, a universal meaning can be given to the concept of now. If time is more fundamental than space, then during the primordial stage, in which space is dissolved into a network of relations, time is global and universal. Relationalism, in the form in which time is real and space is emergent, is the resolution of the conflict between realism and relativity.

Let’s give a name to this version of relationalism, which emphasizes the reality and irreversibility of time and the fundamentality of the flow of present moments. Let’s call it temporal relationalism. We can contrast it with eternalist relationalism, which investigates the hypothesis that space is fundamental, but time is emergent.

RELATIONAL HIDDEN VARIABLES

We thus seek a completion of quantum mechanics which is background independent and relational, and which is framed in a world where time is fundamental and space is emergent. If it involves hidden variables, these must express relations between particles. Thus, the hidden variables do not give us a more complete description of an individual electron; they must describe relations which hold between one electron and other electrons. We can call these relational hidden variables.
 

A. Neumaier

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It's related to Smolin idea that time is fundamental, space is emergent.
He says space is emergent but assumes for his dynamics the Euclidean distance in configuration space, which has no meaning unless space is assumed to be 3D Euclidean.
You will see many physicists read it.
His paper is 3 years old but only 8 times cited - hence probably not much read by experts.

No matter what you think and who read the book, the proposal in his paper, on which his book is based according to him, is deeply flawed.
 
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He says space is emergent but assumes for his dynamics the Euclidean distance in configuration space, which has no meaning unless space is assumed to be 3D Euclidean.

His paper is 3 years old but only 8 times cited - hence probably not much read by experts.

No matter what you think and who read the book, the proposal in his paper, on which his book is based according to him, is deeply flawed.
I think Smolin has reasons for everything. Hope others can share his (technical) reasons.

Note Smolin is no ordinary person. He is the one of the most powerful quantum gravitists in existence having developed loop quantum gravity. He thought of it since 1983. It's been 40 years so I think he has reasons.

I'm very interested in Smolin stuff now because I'm interested in the idea spacetime and matter are all emergent. And Smolin is just grasping at the effective theory.
 

A. Neumaier

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Last edited:
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He says space is emergent but assumes for his dynamics the Euclidean distance in configuration space, which has no meaning unless space is assumed to be 3D Euclidean.
Smolin had written a paper with Fotini Markopoulou that addressed this. See https://arxiv.org/pdf/gr-qc/0311059.pdf "Quantum Theory from Quantum Gravity" This reference was in his book.

His paper is 3 years old but only 8 times cited - hence probably not much read by experts.

No matter what you think and who read the book, the proposal in his paper, on which his book is based according to him, is deeply flawed.
 
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Look. Smolin book has thousands of facts. It may be the greatest quantum book of the century for the masses ever.
Science is not done by writing books for the masses. It is done by constructing models that make testable predictions, and seeing whether the models pass the tests in actual experiments. Unless and until some tests are actually performed based on whatever testable predictions Smolin makes, his ideas will remain speculative hypotheses.
 

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