# crowded quantum information

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18 minutes ago, geordief said:

Can   all systems be described by one wave function(as I think I may have heard)?

I think you could, in principle, but it would be pointless in many cases.

18 minutes ago, geordief said:

Can systems generally also be separated into separate wave functions so that the inseperability  you are talking of is really just specific to entangled particles?

No, IIRC non-separability does not imply entanglement, but entanglement requires non-separability.

12 minutes ago, joigus said:

This example illustrates very nicely an analogue for quantum superpositions, but as any other classical analogue of quantum systems, it only illustrates one particular aspect of them. But I'm sure you agree that no classical analogy can actually embody all the properties of a multipartite quantum system, or of any other quantum system for that matter.

The coin illustrates very well the indefinite nature of the intermediate states, but misses the correlations, and the fact that the state can be brought apart in the spatial components. The gloves cannot reproduce the total indefinition that characterises the state before a measurement is performed.

So we're at a loss for analogies really.

Yes. All analogies will fail at some point, because they’re classical, and we’re dealing with QM. But this, IMO, is slightly better because you have an undetermined state. It just eliminates one of the issues with the glove analogy.

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51 minutes ago, geordief said:

Can   all systems be described by one wave function(as I think I may have heard)?

All systems that are maximally determined, yes. Those are called pure states.

OTOH, it's always possible to prepare systems in non-maximally determined states, called mixtures or mixed states, and those are represented by a matrix built from products of the different sub-states, so to speak, in which the diagonal elements are the statistical weights of the pure states the collective state is made of.

In other words, they represent quantum states in which not all the information has been monitored. The probabilities attached to the different "pure components" (wave functions) don't have necessarily a quantum origin. In that case there is a mixture of quantum uncertainties, and other uncertainties.

Edited by joigus
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5 hours ago, swansont said:

There is no “transaction” or “connection” other than when the entanglement occurs.

I prefer the analogy of a coin flip or toss of a standard six-sided die vs the gloves, because while it is tumbling, the state is undetermined. But when it stops and you observe the side facing you, you instantly know what’s on the opposite side. The coin or die does not need to communicate any information, because that was encoded once the object was made.

The coin flip analogy is a good one. But if one person flips a coin in Hong Kong and another flips a coin in London and their random flips are always anti-coordinated this demonstrates a non-local connection of a sort not permitted by classical physics.

QM does not require a direct physical connection for one particle to be able to effect the condition of a remote particle if the two particles are entangled.

7 hours ago, joigus said:

Quantum mechanics (a totally local theory) predicts quantum correlations for spin

QM permits non-locality. Classical physics does not. That is a major distinction between the two.

7 hours ago, joigus said:

1) If some hidden variables explained quantum correlations for spin => they would contradict quantum mechanics (Bell)

That’s right, hidden variables have been eliminated as an alternate explanation for non-local interactions. Classical mechanics does not permit non-local interactions without a direct physical contact. “Spooky action at a distance” is not possible according to classical physics.

In QM non-local interactions are possible.

Here via wiki are quotes from Bell.  https://en.wikipedia.org/wiki/Bell's_theorem

"In the words of physicist John Stewart Bell, for whom this family of results is named, "If [a hidden-variable theory] is local it will not agree with quantum mechanics, and if it agrees with quantum mechanics it will not be local."[1]

Also, from another source.

"Bell's theorem is a "no-go theorem" that draws an important distinction between quantum mechanics (QM) and the world as described by classical mechanics. It proves that quantum physics is incompatible with certain types of local hidden-variable theories. This theorem is named after John Stewart Bell."

Classical mechanics is always local, QM is not.

7 hours ago, joigus said:

Bell finally sets the record straight and publishes his famous paper on Bertlemann's socks and the nature of reality. => You don't need any magical action at a distance to explain correlations based on a conservation principle. It happens classically all the time!

That may be your personal interpretation of “Bertelman’s Socks” but not mine.

When the particles involved are separated by a distance beyond the range of a “light speed” signal and the results are both random and always correlated like coin flips on two continents, the results are not classical. They demonstrate a non-local correlation.

Edited by bangstrom
Changed affect to effect.
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38 minutes ago, bangstrom said:

The coin flip analogy is a good one. But if one person flips a coin in Hong Kong and another flips a coin in London and their random flips are always anti-coordinated this demonstrates a non-local connection of a sort not permitted by classical physics.

You’ve completely missed the point of the analogy, and changing the analogy negates the point of analogies.

All it shows is if things are different, they are not the same.

38 minutes ago, bangstrom said:

QM does not require a direct physical connection for one particle to be able to effect the condition of a remote particle if the two particles are entangled.

It doesn’t. But it doesn’t effect the condition (or affect it); it doesn’t require communication. (and note previous comments about the limitations of analogies)

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1 hour ago, bangstrom said:

QM permits non-locality. Classical physics does not. That is a major distinction between the two.

No. And the fact that you keep ignoring the references I posted, and my best efforts to explain why, as well as other members', is making this ping-pong match really annoying. Again:

As I posted before, there are claims that generalisations of QM could explore non-locality. Generalisations of QM do not exclude the possibility of angels either. But we haven't seen any, and have serious reasons to believe there aren't any.

For a theory to be actually non-local, not gibberish-non-local like what you're pretending to argue --I know how much you hate maths, but I have no better way to explain-- you would have to have dependence on arbitrarily high-order derivatives in the field variables. That's because you would have to have couplings of the form at 2 distant point $$x$$ and $$x-a$$, for example,

$\varphi_{1}\left(x\right)\varphi_{2}\left(x-a\right)=\varphi_{1}\left(x\right)\left[\varphi_{2}\left(x\right)-a\varphi_{2}'\left(x\right)+\frac{1}{2}a^{2}\varphi_{2}''\left(x\right)-\cdots\right]$

so the fields would be coupled at distant points $$x$$ and $$x-a$$, and therefore would fall well outside the realm of any quantum theory. It faithfully follows the spatial dependence of the classical theories of which it is the quantised version.

I've shown you arguments and authoritative claims that no quantum mechanical theory formulated so far --including quantum field theory-- is non-local. But you haven't answered any of it yet.

Quantum mechanics is not non-local.

Not in its mathematical form, for all we know it isn't, and not in the experiments. If you think it is, it is about time you start to present your case seriously, instead of repeating something you've heard. We are not children.

If you don't like locality, go to another universe.

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11 hours ago, MigL said:

It appears, Bangstrom, that you still think quantum particles have an observable state, before they are actually observed.
And that they need to communicate this state to their entangled partner.
They don't.
And they don't.

Our model says they are, at best, a probability distribution.
If you want to 'imagine' a different  underlying 'reality', you need to come up with a different model.

I have never stated that entangled particles have an observable state before they are observed. I have repeatedly stated that the quantum state of entangled particles is indeterminate prior to the first observation and I have never stated that they communicate. Apparently you have imagined a model different from my own.

3 hours ago, swansont said:

You’ve completely missed the point of the analogy, and changing the analogy negates the point of analogies.

All it shows is if things are different, they are not the same.

You only presented one side of the issue. Entanglement is necessarily two or more sided. I explained how your analogy works on both sides. Your complaint I changed your analogy is petty.

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5 hours ago, joigus said:

No. And the fact that you keep ignoring the references I posted, and my best efforts to explain why, as well as other members', is making this ping-pong match really annoying. Again:

My understanding is that the topic here is about quantum entanglement and about the use of entanglement for superluminal communication at the macro level. That is Alice and Bob.

I thought the we had put to rest with certainty that superluminal communication at the macro level (Alice and Bob) is absolutely impossible under any circumstances. I hope we can also agree that impossibility of non-local communication at the macro level is irrelevant to what may be happening at quantum level.

Your two recent references, are about macro communication of the Alice and Bob type. I have explained in detail why the classical view is irrelevant to what is happening at the quantum level.  More references about the dead issue of classical communication being local is just another irrelevant ‘ping’ waiting for a ‘pong’.

You did have an interesting but lengthy article that included a discussion of the EPR/B experiment that was about quantum entanglement at the quantum level and the authors’ conclusion was that the events were local. My first impression was that they were ignoring the wave-like entanglement itself which is where non-locality resides.

I intend to review the article when I have the time but I don’t intend to comment until I have reviewed the article in detail and considered the validity of my first impression.

6 hours ago, joigus said:

6 hours ago, joigus said:

Quantum mechanics is not non-local

Are you saying, QUANTUM MECHANICS IS LOCAL ?
From my reading, QM allows for non-locality and this appears to be the long term, widely held consensus.

I know there are contrary opinions about all physics being local, including QM, from dubious sources like the Superdeterministic school but can you support your views with more than just personal opinion or your impressions of what Aspect or Bell had to say. I know what they said.

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10 hours ago, joigus said:

All systems that are maximally determined, yes. Those are called pure states.

OTOH, it's always possible to prepare systems in non-maximally determined states, called mixtures or mixed states, and those are represented by a matrix built from products of the different sub-states, so to speak, in which the diagonal elements are the statistical weights of the pure states the collective state is made of.

In other words, they represent quantum states in which not all the information has been monitored. The probabilities attached to the different "pure components" (wave functions) don't have necessarily a quantum origin. In that case there is a mixture of quantum uncertainties, and other uncertainties.

thanks(I doubt I will ever get near understanding most of  that).

Can I ask ,though whether entanglement is an on/off process (for a system of two "objects"  or whether  it might be possible for there to be any grey area even if below the level of conceivable detectability? ,

If not ,might it be possible to model entanglement spreading through a system of more than two objects?

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I am getting more and more confused by this discussion. I wonder if there is a confusion of meanings of concepts you are using. E.g. could you all please be as precise as possible. ' What is Bell's theorem, and Aspect's experiment proving: that there are no local hidden variables, or even none-local variables? Just 'no hidden variables' is not clear enough.

17 hours ago, joigus said:

Bell finally sets the record straight and publishes his famous paper on Bertlemann's socks and the nature of reality. => You don't need any magical action at a distance to explain correlations based on a conservation principle. It happens classically all the time!

I (tried to) read Bell's paper, and found following passage:

Quote

But we will argue that certain particular correlations, realizable according to quantum mechanics, are locally inexplicable. They cannot be explained, that is to say, without action at a distance.

Of course I am not happy with the expression 'action at a distance', (am i critising Bell? Ups...), where it is 'only' correlations we are talking about.

I think you (and I) all agree there is no action in the classical sense, i.e. some for of causation: this would imply FTL communication. And I (as I assume any other physicist) fully accept special relativity.

Another point I do not understand:

On 9/19/2022 at 6:21 PM, MigL said:

These fields are not local to the manifested particle.

<snip>

IOW, the wave equation is also global.

<snap>

The wave function, being a mathematical construct, collapses globally; there is no need for communication/interaction of any kind, sub-luminal or super-luminal.

Since when is global local?

I agree with your last sentence, because we are talking correlation, not causation. There definitely is some none-local aspect in QM, as is said already a few times, because we cannot reproduce this phenomenon based on classical physics.

Further I am suspicious about two referenced articles (one by Joigus and one by MigL) that both base their argument on the MWI. MWI is a metaphysical stance, that heaves the wave function to real, physical existence. MigL's idea that it is just an interpretation, i.e. because (nearly) all QM-interpretations are empirical equivalent, its conclusions should be empirically equivalent seems not valid to me, because any kind of solution of Bell-like experiments is also an interpretation (super-luminal communication, super-determinism, etc). In my eyes, MWI is a nice way to wipe the problem under the carpet. Bohm also is an interpretation, and his quantum potential is definitely none-local.

And last but not least, Anton Zeilinger, in his Dance of the Photons: From Einstein to Quantum Teleportation, says it clearly: local realism is not a valid description of our world, i.e. either locality must be given up, or realism. The latter is also given as a potential way out in 'Bertlmann's socks':

Quote

Fourthly and finally, it may be that Bohr's intuition was right - in that there is no reality below some "classical" "macroscopic" level. Then fundamental physical theory would remain fundamentally vague, until concepts like "macroscopic" could be made sharper than they are today.

I read the German version of Zeilinger's book, which was published by C. Bertelsmann... Not a perfect correlation, but close...

Edited by Eise
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1 hour ago, Eise said:

I am getting more and more confused by this discussion.

To simplify this discussion I would be satisfied if everyone ignores all of my questions and just answers those on Eise's list.

1 hour ago, geordief said:

thanks(I doubt I will ever get near understanding most of  that).

Can I ask ,though whether entanglement is an on/off process (for a system of two "objects"  or whether  it might be possible for there to be any grey area even if below the level of conceivable detectability? ,

If not ,might it be possible to model entanglement spreading through a system of more than two objects?

When entanglement is lost, it is not renewed. Multiple particle entanglements have been observed. As I recall, nearly one hundred particles have been observed to be part of a group entanglement and the count is rising.

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8 hours ago, bangstrom said:

I have repeatedly stated that the quantum state of entangled particles is indeterminate prior to the first observation and I have never stated that they communicate. Apparently you have imagined a model different from my own.

You have mentioned a "wavelike connection and transaction between entangled particles" and the "interaction among entangled particles" along with "QM does not require a direct physical connection for one particle to be able to effect[sic] the condition of a remote particle if the two particles are entangled."

How do these particles interact/engage in a transaction, and how does that not count as communication?

8 hours ago, bangstrom said:

You only presented one side of the issue. Entanglement is necessarily two or more sided. I explained how your analogy works on both sides. Your complaint I changed your analogy is petty.

When you changed my analogy, it ceased to be my analogy. It becomes your analogy. That's not a petty distinction.

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4 hours ago, geordief said:

thanks(I doubt I will ever get near understanding most of  that).

Can I ask ,though whether entanglement is an on/off process (for a system of two "objects"  or whether  it might be possible for there to be any grey area even if below the level of conceivable detectability? ,

If not ,might it be possible to model entanglement spreading through a system of more than two objects?

I'm sorry I've failed.

If I can keep your interest --the question is a really good one--, and until I can find a better way to explain it, please try to teach yourself as much as you can about --keywords-- individual vs collective interpretation of quantum mechanics. Pure states can be understood both ways, while mixed states can only be understood the second way. This piece of literature may be helpful:

If you abide by the collective interpretation* of quantum mechanics all the way, the problem of measurement --in its original formulation-- simply dissolves before your eyes, and J. S. Bell** and M. Nauenberg's words in a rather obscure paper***,

Quote

The question at issue is the famous "reduction of the wave packet". There are, ultimately, no mechanical arguments for this process, and the arguments that are actually used may well be called moral.

suddenly make sense, and you understand why he took so much interest in the double-solution proposed by Bohm and De Broglie. "Reduction of the wave packet" is synonym of "collapse of the wave function."

It is only because the last generations have decided to re-coin the term to mean "decoherence in the density matrix," and only that, that the problem has become almost unintelligible.

* In a nutshell: One electron wave function actually represents infinitely-many electron experiments.

** Probably the most misunderstood theoretical physicist of all time. This is my view.

4 hours ago, Eise said:

I am getting more and more confused by this discussion. I wonder if there is a confusion of meanings of concepts you are using. E.g. could you all please be as precise as possible. ' What is Bell's theorem, and Aspect's experiment proving: that there are no local hidden variables, or even none-local variables? Just 'no hidden variables' is not clear enough.

I'll try to do that, I promise. Unfortunately, I will have to get involved in a lot of self-quoting. One part of the problem is that J. S. Bell shifted his position somehow during the time that he was thinking about this problem. So it's not impossible that he said some things here and there that do not conform to what his final position was. So I'll do my best.

The problem with scientific literature is that sometimes you capture statements that took place when the problem was in the process of beeing understood.

A good example of this is general relativity in the 60's. Lots and lots of peer-reviewed incorrect calculations made it to the literature.

The final judge is, of couse, the experiment, and I'm sure nobody will ever by able to send any kind of superluminal signal.

In my mathematically-biased mind, this is only too clear, as QM proposes nothing more than a finite-order differential equation, so unless this "model" is fundamentally wrong, no non-local effect can be claimed.

But again, I'll try to explain it better.

6 hours ago, bangstrom said:

Are you saying, QUANTUM MECHANICS IS LOCAL ?

Yes, that's exactly what I'm saying.

Now, give me a definition of a non-local theory, please, so that this discussion is not taking place in a conceptual vacuum.

14 hours ago, bangstrom said:

"In the words of physicist John Stewart Bell, for whom this family of results is named, "If [a hidden-variable theory] is local it will not agree with quantum mechanics, and if it agrees with quantum mechanics it will not be local."[1]

Exactly. It would have to be non-local. Intuitively, it's very clear: Because you need wave functions to represent quantum mechanical probability distributions, you would have to update the hidden variables in some non-local way to have some definite variables do the job of updating the wave function. But that would be only because you're trying to picture an internal classical world in the wave function to represent that updating in the wave function.

If you actually believe that no "internal," "hidden-variable" representation of the results implements that updating, and quantum mechanics is sufficient to you, you are freed from that constriction.

Sorry if I wasn't clear before.

Edited by joigus
minor correction
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2 hours ago, joigus said:

One part of the problem is that J. S. Bell shifted his position somehow during the time that he was thinking about this problem. So it's not impossible that he said some things here and there that do not conform to what his final position was. So I'll do my best.

But I hope you remember what you said yourself:

23 hours ago, joigus said:

Bell finally sets the record straight and publishes his famous paper on Bertlemann's socks and the nature of reality. => You don't need any magical action at a distance to explain correlations based on a conservation principle. It happens classically all the time!

Bold by me. Is it not finally then?

2 hours ago, joigus said:

The final judge is, of couse, the experiment, and I'm sure nobody will ever by able to send any kind of superluminal signal.

Of couse. I agree, insofar if you mean with a superluminal signal that it implies a physical causal process (which implicitly would mean transfer of energy and momentum), and that people therefore could use for FTL communication. I think one problem (maybe also part of my problem) is the status of the wave function. My opinion: the wave function itself is not a physical object, so e.g. in Bell like experiments with spin, when Alice measures the spin from here side, there is changing nothing on Bob's side. (See the example of the gloves). The wave function is not a physical object*, which simply means that nothing changes because of Alice's measurement. This would then even be stronger than what I just said: there is no superluminal signal. But there is definitely some form of none-locality. But I would say this just rolls out of the formalism of QM, in the end the results of experiments like Aspect's and is followups are often described as 'QM was right again'.

* Therefore I cannot by in into the MWI.

2 hours ago, joigus said:

In my mathematically-biased mind, this is only too clear, as QM proposes nothing more than a finite-order differential equation, so unless this "model" is fundamentally wrong, no non-local effect can be claimed.

I understand that. QM is often called the best proven scientific theory we have. But we live in a classical world. And in this classical world it just looks like superluminal information transfer. A classical view must fail terribly. How should I imagine a wave function that is stretched over light years, and then collapses over its total length if we do a measurement at one of it's sides? Maybe that is the reason I like to declare the wave function as not-physical. It is part of a calculation recipe, not of nature. As a (dangerous?) analogy: the imaginary number i does also not represent any physical observation ('I walked 5i kilometers today'). But in our calculation recipes in e.g. QM, it plays an important role.

So, and now to cheer up the discussion a little, some pictures:

Bertlmann smells tea presented by John Bell.

Mermin and Bertlmann (yes, a few years later...)

Invitation for a talk by Bell in Vienna, with a student's addition.

Edited by Eise
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2 hours ago, Eise said:

Bold by me. Is it not finally then?

(My emphasis.)

It is even conceivable that the question will never be settled.

It is even possible that, once the semantics of the problem is formulated in --mathematically-- totally unambiguous terms, we find out it corresponds to some of the questions that fall under the category of "undecidable" à la Gödel. Who knows?

In fact, I do believe it may well be undecidable. If generalisations of QM is what this is all about, the sky of possible ideas is the limit.

Let me give you an example. Non-relativistic Schrödinger's equation tells us that the evolution of the wave function is given by a differential equation that's 2nd order in positions and 1st-order in time. This is local out and out. But what if I'm allowed to modify the equation in such a way that there is a non-local term that only becomes relevant when a measurement is performed?

The actual crux of the matter is, IMO, not so much whether the wave function represents something objective, as to how faithfully it parametrizes what's going on or, on the contrary, it parametrizes either more/less, as the case may be, than what we bargained for?

Gauge invariance gives us a clue that it does give us much less --I'd say incommensurably less-- than we bargained for. As soon as you have gauge fields, you can change the wave function from any initial prescription $$\psi$$ that's useful for, eg, collision theory, to any other that locally differs from your original choice by a (time-position)-dependent phase factor, and may be carrying other useful/significant/meaningful information.

Who is to say the immensely rich landscape of infinitely-many gauge prescriptions does not carry a subgroup that tells us which one of the alternatives of a measurement is the one we are measuring?

Because that's a --blatantly deliberate-- rethorical question, let me answer that explicitly, and face the possible consequences of any arguing against that may arise:

Nobody.

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Hear hear. Vastly preferable to these other explanatons in my estmation.

On 9/19/2022 at 9:21 AM, MigL said:

Upon collapsing the wave function, both particles assume their observed states, and the correlation is evident, just as would happen for a single particle wave function.
The wave function, being a mathematical construct, collapses globally; there is no need for communication/interaction of any kind, sub-luminal or super-luminal.

Mathematically constructed into a probability distribution, collapsing any semblance of reality. Something is rotten in Denmark.

On 9/19/2022 at 4:20 PM, geordief said:

Do the particles  exist when their state is undefined?

Or do they only exist when there is an interaction?

I think this may have been answered earlier but if the state of one entangled particle is measured does it matter when the state of the other is measured?

Could it be  centuries later so long as there had been no other  interactions  in the meantime ?

Also you mentioned the global fields:

Would I be right to think that these global fields arose  at the earliest epochs that have been modeled and that they have been "evolving" ever since ,like some kind of  physical cosmic organisms ?

Beables, being mentioned elsewhere by joigus (whom I have deduced is actually a supercomputer), seem worthy of an introduction here given the discussion and questions you're asking:
From Local Beables and the Foundations of Physics by Tim Maudlin New York University

Quote

Introduction: The Theory of Local Beables
John Bell’s most celebrated contribution to the foundations of physics is his
famous theorem. The theorem demonstrates that any physical theory capable of
generating the predictions of the standard quantum-mechanical algorithm, in
particular the prediction of violations of Bell’s inequality for experiments done at
space-like separation, cannot be local. The sense of “locality” used here is the same
sense that Einstein had in mind when he pointed out that the standard
interpretation of the quantum algorithm was committed to “spooky action at a
distance”.
To this day, the import of Bell’s theorem is not universally appreciated. I
take up that task. It is properly the main focus during this 50th anniversary of that
great achievement.

But it is also important to recall and celebrate Bell’s other achievements. In
many of his later writings, including “The theory of local beables”, “Quantum
mechanics for cosmologists”, “On the impossible pilot wave”, “Beables for quantum
field theory”, “Six possible worlds of quantum mechanics”, “Are there quantum
jumps?” and “Against ‘measurement*1”, Bell turned his attention to the more general
problem of physically construing the mathematical formalism used to derive these
predictions.
This activity is often denominated “interpreting quantum theory”, as if
there were some precise physical theory that might somehow be supplemented
with an “interpretation”. Once framed this way it is easy to ask: But if I already have
a theory in hand, what can be gained by supplementing it with an “interpretation”?
Many physicists, at this juncture, are happy to conclude that “interpretations” are
not a matter of physics at all—maybe they are only of interest to philosophers—and
that therefore the whole enterprise of “interpreting quantum theory” is not within
the purview of physics per se.

What then is in the purview of physics proper? One answer to this question
goes under the banner “instrumentalism”: all physics, as such, is concerned about is
predicting the outcomes of experiments. In the service of making these predictions
physicists may invent various mathematical formalisms, together with rules for
their use as prediction-generating instruments. It is neither necessary, nor perhaps
even desirable, to accompany these prediction-generating algorithms with any
“picture” or “account” or “story” of what exists beside the instruments. Indeed, a
common myth about quantum theory is that it is actually impossible to provide any
such accompanying story, and that the progress of physics requires the positive
renunciation of the desire for one. If this were correct then the desire for anything more than such a prediction-generating set of rules must arise from concerns
outside of physics proper.

[Op.Ed.:"Shut up and calculate": do these wave equations; ask no questions, we got this.]

[*1 All of these are reproduced in Bell 2004, from which the page citations will be
taken in this paper.]

Bell rejected this account of physics root and branch. As usual, he expressed
his dissatisfaction so clearly and elegantly that there is nothing to do but quote him:

Quote

In the beginning, natural philosophers tried to understand the
world around them. Trying to do that they hit upon the great idea of
contriving artificially simple situations in which the number of factors
involved is reduced to a minimum. Divide and conquer. Experimental
science was born. But experiment is a tool. The aim remains: to
understand the world.
To restrict quantum mechanics to be
exclusively about piddling laboratory operations is to betray the great
enterprise. A serious formulation will not exclude the big world
outside the laboratory. (Bell, 2004: 216-17)

Physics itself aims at more than just predicting the outcomes of experiments. What
more is easily stated: physics aims at a complete and accurate account of the
physical structure of the universe. Of course! And the different “interpretations of
quantum theory” are really different physical theories, which happen to make
exactly, or nearly, the same predictions as the standard quantum-mechanical
algorithm. But what general features should such a physical theory have?
One of Bell’s signal contributions to this problem is what he called the theory
of local beables.
There is a certain irony here. For while his most famous
achievement was to show that the non-locality that Einstein long ago identified in
the standard “interpretation” of the quantum formalism (the Copenhagen

interpretation) could not be eliminated, his attention to local beables highlighted
just the opposite problem: the standard story fails to be clear about what exists
locally. So the standard account, if one tries to take it seriously, both contains a nonlocality that was not acknowledged and lacks a different kind of locality that it
requires.
It is this second sort of locality I want to discuss here.
Any clearly formulated and articulated physical theory should contain an
ontology, which is just a statement of what the theory postulates to exist. The word
“ontology” can perhaps look a little intimidating, or overly “philosophical”, so Bell
invented his own terminology for this: the “beables” of the theory. Stating what the
beables of the theory are is nothing more nor less than stating what the theory
postulates as being physically real. Once what the ontology is has been made clear,
then (and only then) can one go on to ask what the ontology does, how it behaves.
This question is answered by a dynamics: a mathematically precise characterization
of how the beables change through time. The dynamics might be deterministic or
might be stochastic. But according to the professional standards of mathematical
physics, the dynamics ought to be precise. It should be specified in sharp equations
relating the beables, rather than by using vague words (such as “measurement”). [...]

okay so only just an amateur.

On 9/18/2022 at 7:06 PM, bangstrom said:

There are two definitions of "projection". One is about light and another is the name of a defense mechanism.

Ohmygod we're going into soft science.

On 9/17/2022 at 11:04 PM, bangstrom said:

One provision of Occam’s Razor is that it cautions against the addition of unknown and unobserved entities like Leprechauns or worlds beyond our own to explain a hypothesis

An inter-dimensonial leprechaun wearing different colored socks (as a distraction) is going to peaky blinders you with occam's razor; or, how is MWI any worse than your non-local, hidden variables FTL solipsistic "it only exists once I look at it" interpretation?

On 9/19/2022 at 9:21 AM, MigL said:

Upon collapsing the wave function, both particles assume their observed states, and the correlation is evident, just as would happen for a single particle wave function.
The wave function, being a mathematical construct, collapses globally; there is no need for communication/interaction of any kind, sub-luminal or super-luminal.

Again, I must be Mr. diehard, I refuse; I would prefer super-luminal as an explanation, but maybe that's the easy way.

On 9/20/2022 at 7:37 AM, joigus said:

What Aspect et al. proved is that quantum mechanical probabilities give exactly what quantum mechanics --in its close mathematical form for angular momentum-- predicts. Even for the crucial case that Bell et al. proposed.

Because they were confirmed, and John Bell proved that quantum mechanics involves something other than classical logic, we believe quantum mechanics is correct (about angular momentum, anyway) and non-locality was never necessary in the first place.

I mentioned to you elsewhere that QM wants to have it's classical angular momentum and it's nebulous probability cloud, too; Murray Gell-Mann did not go home, he went to go camp outside with James Hartle and Roland Omnès,

"The consistent histories approach can be interpreted as a way of understanding which properties of a quantum system can be treated in a single framework, and which properties must be treated in different frameworks and would produce meaningless results if combined as if they belonged to a single framework. It thus becomes possible to demonstrate formally why it is that the properties which J. S. Bell assumed could be combined, cannot. On the other hand, it also becomes possible to demonstrate that classical, logical reasoning does apply, even to quantum experiments – but we can now be mathematically exact about how such reasoning applies."
Not that I understand this QM interpretation either.

18 hours ago, Eise said:

Quote

Fourthly and finally, it may be that Bohr's intuition was right - in that there is no reality below some "classical" "macroscopic" level. Then fundamental physical theory would remain fundamentally vague, until concepts like "macroscopic" could be made sharper than they are today.

I concur, it seems that a "weakening of the concept of reality" is required to take on board the results of QM's mathematical construction's interpretations. They want to grab the lowest hanging Bohr electron then remove any concept of it having an actual velocity in an orbit... I say, "God does not play dice", but sure, has probably been to Monte Carlo, and helped develop many good methods. As for back to the OP, no, not likely we can increase bandwidth, unless we can suss out the demon in the details because I'm pretty sure we're missing something fundamental and it's causing fundamental confusion.Hence, I think I can safely say noone understand quantum mechanics.

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16 hours ago, swansont said:

You have mentioned a "wavelike connection and transaction between entangled particles" and the "interaction among entangled particles" along with "QM does not require a direct physical connection for one particle to be able to effect[sic] the condition of a remote particle if the two particles are entangled."

How do these particles interact/engage in a transaction, and how does that not count as communication?

The effect of the loss of a wavelike connection is immediate and there is no transfer of information from one particle to the other so this does not qualify as a communication.

15 hours ago, joigus said:
21 hours ago, bangstrom said:

Are you saying, QUANTUM MECHANICS IS LOCAL ?

Yes, that's exactly what I'm saying.

Now, give me a definition of a non-local theory, please, so that this discussion is not taking place in a conceptual vacuum.

Your claim that QM is local is not on the level of claiming, ‘The Earth is flat.’ but it lies in that direction. The burden of explaining one’s view when it runs counter to the conventional wisdom lies mainly with the person making the claim.

I gave you a perfectly good example of non-locality and you said I was wrong and confused and then you offered another personal obfuscation to prove your point.

Why should I give you another example of non-locality so you can issue more demeaning comments

about my competence and state of mind and complain that I am playing ping-pong.

I gave you my definition of of non-locality and I have asked for your definition more than once but you have never given me an answer. I have no Idea of what you consider to be “non-locality” except that it is always other what I consider to be non-locality.

That is part of the conceptual vacuum here.

Edited by bangstrom
Changed gave to given.
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4 hours ago, bangstrom said:

I gave you my definition of of non-locality and I have asked for your definition more than once but you have never given me an answer. I have no Idea of what you consider to be “non-locality” except that it is always other what I consider to be non-locality.

(My emphasis.)

Here:

On 9/22/2022 at 1:53 AM, joigus said:

For a theory to be actually non-local, [...] you would have to have dependence on arbitrarily high-order derivatives in the field variables. That's because you would have to have couplings of the form at 2 distant points $$x$$ and $$x-a$$ for example,

$\varphi_{1}\left(x\right)\varphi_{2}\left(x-a\right)=\varphi_{1}\left(x\right)\left[\varphi_{2}\left(x\right)-a\varphi_{2}'\left(x\right)+\frac{1}{2}a^{2}\varphi_{2}''\left(x\right)-\cdots\right]$

so the fields would be coupled at distant points $$x$$ and $$x-a$$ and therefore would fall well outside the realm of any quantum theory. It (QM) faithfully follows the spatial dependence of the classical theories of which it is the quantised version.

(In this self-quote, I've just edited minimally for clarity, and highlighted the edited terms in boldface, as well as terms that point to the parts that you really had better read carefully before you embarrass yourself any further.)

4 hours ago, bangstrom said:

Why should I give you another example of non-locality so you can issue more demeaning comments

about my competence and state of mind and complain that I am playing ping-pong.

If you don't read the previous posts, you're only going to make this thread unbearably difficult to follow for everybody, including yourself.

If I sounded demeaning to you, I sincerely apologise. It wasn't what I meant. But now I think it's obvious why I'm annoyed. If, for some reason, you don't like the maths, or you find its sheer mention annoying, or you don't think it's part of the argument, just tell me and I will try to re-phrase in some other way, because it is. It is an essential part of the argument. Don't just dismiss it or ignore it.

I also remind you that you were the first in trying to make this personal:

On 9/18/2022 at 11:46 PM, bangstrom said:

Where were you when we discussed this before?

What does that have to do with anything?

Please, use the quote function --as I did-- to direct me to your definition of non-locality, as I seem to have missed it.

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7 hours ago, bangstrom said:

The effect of the loss of a wavelike connection is immediate and there is no transfer of information from one particle to the other so this does not qualify as a communication.

What is the nature of this "wavelike connection"? I think the loss of some connection can count as communication.

I agree that there is no transfer of information, and as such there's no point in arguing about non-locality, since no communication removes any need to determine if communication is superluminal or not. But it also requires that there be no "connection" or "transaction" between the particles. You can't have it both ways.

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9 hours ago, NTuft said:

Beables, being mentioned elsewhere by joigus (whom I have deduced is actually a supercomputer), seem worthy of an introduction here given the discussion and questions you're asking:
From Local Beables and the Foundations of Physics by Tim Maudlin New York University

Thanks for the compliment, but I can guarantee to you I'm no computer, and I'm no superman. I do have my kryptonite, like everybody else. I do spend a lot of time thinking, and reading, and doing calculations about these things, and trying to keep up to date on the experimental front. When I say something stupid, or just sloppy, I retract and apologise, and some people on these forums can bear witness to that.

The "beable" idea is very interesting, but it would take us too far off tangent, I think. It's also too mathematical perhaps, if you take my meaning.

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On 9/22/2022 at 4:09 AM, Eise said:

Since when is global local?

Guilty as charged, Eise.
I am often confused by terminology, and while I see a definite difference between 'non-local' and 'global', their polar opposite is 'local' in both cases.

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10 hours ago, swansont said:
17 hours ago, bangstrom said:

The effect of the loss of a wavelike connection is immediate and there is no transfer of information from one particle to the other so this does not qualify as a communication.

What is the nature of this "wavelike connection"? I think the loss of some connection can count as communication.

I agree that there is no transfer of information, and as such there's no point in arguing about non-locality, since no communication removes any need to determine if communication is superluminal or not. But it also requires that there be no "connection" or "transaction" between the particles. You can't have it both ways.

I can agree that the loss of a connection can count as a communication but the word ‘communication’ has been specifically defined by the quantum computer people. They claim that no communication can be faster than light. The loss of entanglement is an exception because it amounts to only one qubit of information and nothing intelligible can be gathered from a single qubit. I don’t remember how many qubits it takes to officially qualify as a ‘communication’ but it may be something as low as three.

The John Cramer- Ruth Kasner team refer to entanglement as a “transaction” in their TIQM theory where T is for transactional. I prefer the word ‘transaction’ as well and I think that has come to be the most commonly used term for what is happening.

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14 hours ago, joigus said:

14 hours ago, joigus said:

14 hours ago, joigus said:

14 hours ago, joigus said:

14 hours ago, joigus said:

14 hours ago, joigus said:
On 9/21/2022 at 6:53 PM, joigus said:

Edited by bangstrom
I thought my [QUOTE] function quit working but my quotes were stacking ABOVE what I was writing while I was looking for them BELOW. It was an unreadable mess.
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When the quote function is playing up, I've found that copy and paste works better.

But there seems to be a problem quoting, editing. Some functions seem not to be working.

Edited by joigus
Software failing
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1 hour ago, joigus said:

When the quote function is playing up, I've found that copy and paste works better.

But there seems to be a problem quoting, editing. Some functions seem not to be working.

Thanks, that is good to know. Copy and paste is doing it the old familiar way.

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3 hours ago, bangstrom said:

I can agree that the loss of a connection can count as a communication but the word ‘communication’ has been specifically defined by the quantum computer people. They claim that no communication can be faster than light. The loss of entanglement is an exception because it amounts to only one qubit of information and nothing intelligible can be gathered from a single qubit. I don’t remember how many qubits it takes to officially qualify as a ‘communication’ but it may be something as low as three.

The John Cramer- Ruth Kasner team refer to entanglement as a “transaction” in their TIQM theory where T is for transactional. I prefer the word ‘transaction’ as well and I think that has come to be the most commonly used term for what is happening.

TIQM uses, as far as I understand, an interaction between the particles

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