Questions about Bell: Answering Philosophical Difficulties

[jambaugh]

Pardon the long post...

What evidence do either of you use to come to these one of contrary conclusions?
[note: by ‘reality issues’ I assume you guys mean “Realism” as in the realism of a classical reality verses the possible reality of a multidimensional and/or “FTL” wave function or entanglement collapse.]

Contrary to what? Yes I mean realism in this sense. Specifically the modeling of the universe or that part of the universe affecting the outcome of an experiment as a set of points corresponding to states in some manifold or state set. This idea of "the state of the system" or "the state of the system and its environment" be that local or not is all that one needs in essence to derive Bell's inequality. Allow non-local causation if you like. Include any hidden variables you like. You still get outcomes of experiments caused by states of reality and modes of preparation of the system resulting in probability distributions over this set of states. The probability distributions will be positive specifically because in a reality picture negative probability is meaningless. The distributions will be additive over subsets because of the logic of classical reality. Therefore the probabilities for the set difference (XOR) for two sets of experimental outcomes ...
M(A,B)\equiv Pr(A\cap \overline{B}\cup B\cap \overline{A})
will act as a metric with regard to the triangle inequality:
M(A,B) + M(B,C) \ge M(A,C)
This in essence is Bell's inequality. This inequality does not hold under QM...that is if you assert that these sets of outcomes correspond to quantum observables.

Note that you can take a given quantum theory and embed it within a much larger "conspiracy type" classical theory with the same outcomes. One is thereby failing to match up the classical observables with quantum observables. Such is the case in the Bohm pilot-wave type theories where in the wave-functions of the original quantum theory becomes a classical wave unobservable in practice but granting god-like powers observable in principle. However if you in turn "quantize" these again you get a whole new level of Bell inequalities and their violation.

The principle reason I object to these is that they also require non-local causation which in turn means future acting on past. How can we then say the system is in a given state if in the future some cause could revise history and change that state. The state-of-reality picture breaks down by itself without need of invoking QM.

Ultimately I think the order of causation necessarily dictates the time arrow and thus "backwards in time" casuation is both physically and semantically meaningless. The past is the class of phenomena which causally effected our current process of thinking and remembering.

Similarly nearness in space fundamentally is defined by the relative magnitude of causal effect. The sun warms my face more than Alpha Centauri, it is nearer. My fingers feel my keyboard while I have no sensation of yours. It is nearer. The only mystery is how phenomena shake down into events which can be parameterized in 3+1 dimensional space-time. IMNSHO That's what will reconcile quantum theory and Einstein's GR.

Neither of you can use Bell or EPR-Bell as evidence as it is only able to address “Local” as understood by Einstein which requires both Locality AND Realism.

I can speak of locality without invoking classical realism. You are right about Einstein but we can translate his concept of local objective realty into one of locally causal phenomena...what I would call local actuality.

As I explained and speaking only for myself and not ThomasT, I see specifically EPR-Bell as evidence that we must abandon conventional classical reality. As bad as that may sound on first glance it is a proper step toward operationalism. It is not states of reality we see in the lab but phenomena, or as they used to say in the 60's-70's "happenings".

From what do you derive assurance that any solution that may come in the future claiming to be more complete than the Non-Locals (from QM to BM to Strings) should not be required to explain the non-local implications of EPR-Bell as if non-locality means nothing.

Again I qualify that I seen no non-local implications to either QM or EPR-Bell. It is simply a matter of classical being classical (wherein Bell's inequality applies) and quantum being quantum wherein it doesn't. Classical reality is fine for classical theory and wrong for quantum theory. No mysteries no worries.

As a Local Realist like myself (the Einstein claim) I see that as the exact obligation of any LR explanation.

To be repetitive, I don't see any LR explanation possible due to the R issue not the L one. Call me a Local Actualist in contrast to your Local Realism. It is more than a preference. It is a position I've derived from my study of the foundations of QM and its logical structure. Classically probabilities are measures. Quantum mechanically they are squares of measures.
Let me also add that completeness changes meaning in the absence of the concept of state.
QM is quantum complete in a way that CM is not. You have a larger class of observables for a given distinct set of simultaneously distinguishable observable values.

Until a detailed description in LR terms can match the measured EPR-Bell results the Non-Local solution currently in use must be considered at least viable if not most likely complete, regardless of what my or anyone’s personal preference might be.

I'm not clear about what you mean by "Non-Local solution currently in use". If by solution you mean interpretation then the majority of polled quantum theorists adopt the Copenhagen interpretation (which I've been explaining) wherein reality is dropped and locality may then be preserved. If on the other hand you mean by "solution" the actual theory with predictions which match empirical data, QM wins and it is a local causal theory. Pay attention to the meaning of "locality" it is rooted in the causal connection of events and no reference to the states of objects or reality is necessary. It is operationally meaningful in a way that "state of reality" is not.

And IMO any solution that wishes to discredit the current explanation of EPR-Bell results must do so using both locality and realism, in other words find the complete solution Bell himself was originally looking for that demonstrates a more complete hidden variable LR solution as possible.

Again I'm not sure to which "current explanation" you are referring. The current consensus denies what Bell "was originally looking for" and failed to find.

Arguments trying to decide if we have a mis-perception in understanding nature because of nonlocality in nature verses nature not based on realism have nothing to do with Bell, as they only address which Non-Local approach is preferable.

I agree with your words though probably not your meaning. I assert Bell has nothing to do with locality per se. You seem to presume that Bell-EPR automatically imply Non-Locality which blinds you to seeing my point... that it has nothing to do with locality per se.

You need to carefully study the distinction between the lattice of logical propositions about a classical system's state (a lattice of sets with inclusion as the order relation) and the lattice of logical propositions about a quantum system's observables (a lattice of subspaces with sub-space inclusion as the order relation).

The fact that we get a continuum of observables and hence a continuum of distinct logical proposition for a quantum system which can has only a finite spectrum of distinct simultaneous observable values precludes any operationally meaningful "reality" description of that system. The basic laws of classical probability will be violated by the predicted quantum transition probabilities no matter how many hidden variables you introduce...

or you must incorporate a conspiracy theory wherein God knows exactly what future experiments we will make and tweaks and convolutes the initial hidden variables in such a way as to mimic quantum predictions. In either case reality is meaningless or inscrutable to us mere mortals. It should thus IMNSHO be excised from the theory all together.

What happens happens. If we can quantify rules about what happens that predict then we're ahead of the game. Test them empirically and you have science. Hypothesize about the deeper reality behind it and you have mysticism.

Mysticism (from the Greek μυστικός – mystikos- 'seeing with the eyes closed, an initiate of the Eleusinian Mysteries; μυστήρια – mysteria meaning "initiation"[1]) is the pursuit of achieving communion, identity with, or conscious awareness of ultimate reality, the Other, divinity, spiritual truth, or God through direct experience, intuition, or insight.--Wikipedia

 

[RandallB]

Contrary to what?

I must admit I have trouble following how either argument relates to EPR & Bell, but I don’t think I miss read or misquoted the earlier posts.
Is not your position contrary to the ThomasT position that reality issues are a red herring when you disagree to claim that only the locality is a red herring?

Your explanation boils down to your statement:

To be repetitive, I don't see any LR explanation possible due to the R issue not the L one. Call me a Local Actualist in contrast to your Local Realism.

It is more than a preference. It is a position I've derived from my study of the foundations of QM and its logical structure. …. ….

That “Position” of yours is simply an equivalent alternative interpretation of QM CI, no more. If you like you may call QM an equivalent interpretation of your “Local Actualist” view. Just because you slide in the word “local” does not make it the same as the LOCAL be addressed by Bell or EPR-Bell experiments. Local in Bell means Einstein Local and requires both “L” and “R” nothing so far has eliminated “L” as an issue for Bell.

I'm not clear about what you mean by "Non-Local solution currently in use". If by solution you mean interpretation then the majority of polled quantum theorists adopt the Copenhagen interpretation (which I've been explaining) wherein reality is dropped and locality may then be preserved.

First CI does not preserve locality. The currently accepted Non-Local solution presumes that any Non-Local solution including your “Local Actualist” interpretation are equally viable solutions superior to any possible LR solution as Einstein called for; it is that simple.

I agree with your words though probably not your meaning. I assert Bell has nothing to do with locality per se. You seem to presume that Bell-EPR automatically imply Non-Locality which blinds you to seeing my point... that it has nothing to do with locality per se.

In the context of Bell & EPR-Bell “Local” only refers to “Einstein Local” which requires both locality and realism. Therefore the only theory that can be "NOT Non-Local" is Einstien Local LR where locality is clearly significant.
I’m not at all blind to your point: you prefer a Non-Local interpretation you call “Local Actualist” over other Non-Local solutions to EPR-Bell.
You seem to miss the point that EPR-Bell can not differentiate your “Local Actualist” view from any other Non-Local view.

 

[jambaugh]

I'll be brief. What you say w.r.t. Bell invoking "good ole" Einsteinian LR is correct. But remember it is an RAA hypothesis which is negated.

Not(Local and Real) = Not Local OR Not Real.
Thus QM can be interpreted as (Local and Not Real) or (Real and Not Local) or (Not Real and Not Local).
I assert through CI it's Local and Not Real.

I also assert that the Local part is NOT essential to Bell's derivation.

I think you, in holding onto the Real part, are insisiting that locality is negated.
QM is a Local theory. I take issue with your insisting it is not and ask you to expand upon your assertion if you wish to continue making it.

 

[RandallB]

I'll be brief. What you say w.r.t. Bell invoking "good ole" Einsteinian LR is correct. But remember it is an RAA hypothesis which is negated.

Not(Local and Real) = Not Local OR Not Real.
Thus QM can be interpreted as (Local and Not Real) or (Real and Not Local) or (Not Real and Not Local).
I assert through CI it's Local and Not Real.

I also assert that the Local part is NOT essential to Bell's derivation.

I think you, in holding onto the Real part, are insisiting that locality is negated.
QM is a Local theory. I take issue with your insisting it is not and ask you to expand upon your assertion if you wish to continue making it.

Do you not know what a Local Realist is?
Or do you think I don’t know what I’m describing myself as means?
Since I declare myself to be LR how can you possible think I insist that locality is negated?
First unlike your claim I do not “insist” on anything and certainly not that locality has been successfully negated; that is a claim made by Non-Local theory such as yours. As a Local Realist my EXPECTATION is that nature is LOCAL.

Never did I “invoke” Einsteinian LR as being “correct”, I sited it as the definition of what ”LOCAL” means w.r.t. Bell and EPR-Bell. And as you described the different options for what Local means, it gives Four possible discriptions for how nature might work wrt Bell.
First only ONE that is Local where nature is:
#1 (Local and Real)
And THREE that are Non-Local where nature is:
#2 (Local and Not Real)
#3 (Real and Not Local)
#4 (Not Real and Not Local)
[DEF: Real = the realism of a classical reality verses the possible reality of a multidimensional and/or “FTL” wave function or entanglement collapse].

You are correct I do insist that QM is not Local (#1) and I also insist that QM has not been shown to be #2 (Local and Not Real). As you requested I can expand my assertions:
Never has anyone claiming that QM is #2 "Local and Not Real" (or #1 LOCAL for that matter), been able to provide any evidence to support such a claim.
Including where you insist that QM is #2 (Local Actualist but Un-Realistic) but have proved no evidence to support your claim as I requested back in post #120.

Mind you evidence does not need to be experimental; we can accept a description of how Bell & EPR-Bell works in nature using rational logic.

That said I have no doubt that if you start from and hold to a premise that Nature is #2 (Local and Not Real) you will be able to logically conclude that Nature must be “Local Actualist but Un-Realistic”. However that IMO would be Circular Logic and unacceptable proof.

So I in turn take issue with your insisting that QM is #2 (Local and Not Real) and ask you provide some rational and logical evidence without presuming the conclusion, to support your assertion if you wish to continue making it.

 

[ThomasT]

Did you read my post or just react to it?

Yes. I read it, and then I reacted to it.

No one has claimed that Bell Theorem applied to EPR-Bell experiments helps in any way to select the best one of many non-local explanations ...

Many claim that experimental violations of Bell inequalities prove (or at least support) the notion that ftl or instantaneous material propagations are a fact of nature. My contention is that experimental violations of Bell inequalities tell us nothing of the sort.

... such as your “Global Theory” as better than any other non-local theory.

Global is not synonymous with nonlocal. Global refers to an observational perspective.

I suspect you are having a problem with defining the term “Local” and do not understand that redefining a new term for “Global Local” is NOT the same as “Local”.

I use the terms local, Einstein local, and nonlocal in the same way that you do. That is, I think they mean the same things to me that they do to you.

However, I do suspect that you might be using the term global differently than how I meant it, and how it's usually used.

Global refers to an observational perspective. It's only in the global perspective that entanglements emerge. The global perspective correlates the rate of coincidental detection with the angular difference between the polarizer settings. The correlations that emerge, as P(A,B) changes as a function of cos^2(|a-b|), have nothing to do with ftl or instantaneous material influences propagating between a and b, or A and B, or A and b, or B and a. It can all be understood, I think, in terms of local propagations. There's a common cause wrt emission and a common cause wrt the global perspective. There is, of course, an instantaneous connection between changes in a and/or b and changes in |a-b|.

 

[RandallB]

You react by rolling your eyes, because you do not know what the term LOCAL means wrt Bell. And that is made clear when you say:

Global is not synonymous with nonlocal. Global refers to an observational perspective.

I use the terms local, Einstein local, and nonlocal in the same way that you do. That is, I think they mean the same things to me that they do to you.

However, I do suspect that you might be using the term global differently than how I meant it, and how it's usually used.

Global refers to an observational perspective. … There is, of course, an instantaneous connection between changes in a and/or b and changes in |a-b|.

I can allow that “Global” can be taken as an observational perspective, but when you use that perspective to build a “Global Theory” the version “Global local” you create cannot be used in place of what Bell uses for LOCAL as you have been are doing. So NO you are not using those terms the same way I do. You even acknowledge your perspective uses an instantaneous connection between distant settings a & b. Einstein was very clear that is not Einstein Local nor is it local wrt Bell Local.

I already referred you to an https://www.physicsforums.com/showthread.php?t=181904" addressing “BM local” before, your “Global Local” is no different so do read it.

Also, on “how it's usually used” other than your approach here where else is “Global” and especially “Global Local” used by anybody?
As far as I can tell this is a not something found in standard publication, and as a additional non-local interpretation it may be something you’d like to consider for the “Independent Research” area of these forums if youd like to discribe it in greater detail. But it does not refute Bell or "solve" Bell any more so than any other Non-Local and should not be presenteted that way.

 

[ThomasT]

You react by rolling your eyes, because you do not know what the term LOCAL means wrt Bell. And that is made clear when you say:

"Global is not synonymous with nonlocal. Global refers to an observational perspective.

I use the terms local, Einstein local, and nonlocal in the same way that you do. That is, I think they mean the same things to me that they do to you.

However, I do suspect that you might be using the term global differently than how I meant it, and how it's usually used.

Global refers to an observational perspective. … There is, of course, an instantaneous connection between changes in a and/or b and changes in |a-b|."

Which of my above statements (in boldface type) makes it clear to you that I "do not know what the term LOCAL means wrt Bell."?

Here's a quote from Bell (in italics) taken from the thread you provided a link to:

Consider a theory in which the assignment of values to some beables "lambda" implies, not necessarely a particular value, but a probability distribution, for another beable A. (...)
Let A be localized in the space-time region 1. Let B be a second beable localized in a second region 2 separated from 1 in a spacelike way. Now my intuitive notion of local causality is that events in 2 should not be causes of events in 1, and vice versa.

By the term local, then, I mean that the spacelike separated data streams at A and B (in, say, a standard EPR-Bell optical setup) are not causally related to each other. That is, you can do anything you want to a (the polarizer setting at A) and it can have no effect, within a certain time interval (the coincidence interval) on the results at B, and vice versa.

Using this definition, qm is a local theory -- because P(A) and P(B) are always just 1/2.

And, no matter what definition of locality you use, experimental violations of Bell inequalities tell us nothing about whether or not there is a direct causal link between events at A and events at B -- because the data streams at A and B remain random and the rates of detection remain unchanged no matter what is done at one end or the other.

There might be FTL propagations in some medium or interacting media in the deep reality underlying quantum experimental phenomena, however as long as the data streams at A and B are random and the individual detection rates remain the same, then there isn't anything that these experiments can tell us about the reality of nonlocality that qm doesn't already tell us without them. Like the light medium or ether, so long as nonlocality (even if it exists) remains undetectable, then it remains unusable (and effectively nonexistent).

I can allow that “Global” can be taken as an observational perspective, but when you use that perspective to build a “Global Theory” the version “Global local” you create cannot be used in place of what Bell uses for LOCAL as you have been are doing.

Where did "Global local" come from? Did I say that?

Look, the words nonlocal and local refer to the existence or not of FTL causal propagations in nature. The words global and individual refer to experimental designs or observational perspectives. When a theory models, say, the correlations of two or more spatially separated sequences of events, then it is taking a global perspective. When, a theory models, say, the individual setup at A or B in a standard EPR-Bell test, then it isn't taking a global perspective.

You even acknowledge your perspective uses an instantaneous connection between distant settings a & b.

Yes, and the reason I italicized instantaneous connection is because the connection isn't a physical one between a and b. It has only to do with the global observational perspective. We're considering a and b together, not separately. The variable is (|a-b|), so any change you make in a (or b) results in an instantaneous change in the global variable. This is the independent variable in the functional relationship between the angular difference in the polarizer settings and the rate of coincidental detection. The dependent variable, (A,B) is also a composite, or global, variable.

Einstein was very clear that is not Einstein Local nor is it local wrt Bell Local.

Right, the instantaneous connection between changes in a and/or b and changes in |a-b| has nothing to do with locality or nonlocality, but only with the scope of the observational perspective.

I already referred you to an https://www.physicsforums.com/showthread.php?t=181904" addressing “BM local” before, your “Global Local” is no different so do read it.

I enjoyed reading that thread. I think it's possibly a misnomer to call BM a nonlocal theory. Better perhaps to call it simply a global theory, because it doesn't tell us anything about the existence (or not) of FTL causal propagations in nature. It's just based on the idea that everything in the universe is entangled with respect to the gross behavior of the universe. It's also not a realistic theory. It's unique constructions are based on metaphysical speculation. A realistic theory would be one based solely on the behavior of experimental instruments. So, to the extent that a theory is based on instrumental behavior, it's a realistic theory. So, standard quantum theory is a pretty realistic theory, though I don't think that either local or nonlocal necessarily apply to it since it doesn't tell us anything about the existence (or not) of FTL causal propagations in nature.
--------

There's still the question of how to understand the correlations in a standard optical EPR-Bell experiment. Are they any more mysterious than the correlation between polarizer and analyzer in a standard polariscopic setup? I don't think so.

 

[RandallB]

Now you are just getting tiresome if not objectionable.
No one is going to take you seriously if you just keep restating the same false claims.

Using this definition, qm is a local theory -- because P(A) and P(B) are always just 1/2.

That is just plain false, QM does not match the observed results by 1/2 , QM matches observations 100%. It is the current LR descriptions which unlike QM are restricted to “Bell Local" conditions that have only been able to match observations by 1/2. QM is clearly NOT Bell Local (AKA not Einstein Local or Local wrt Bell)

Where did "Global local" come from? Did I say that?

Smile all you want wiseguy, I don’t find you funny just objectionable.
It is you that are designing something “Global” using a version of “local” that is clearly NOT Bell Local. I don’t care if you call it “TommyT Local” but shorting the name to “local” does not make LOCAL WRT Bell.

As I said you can only think that if you do not know what “Local” means when working on Bell. Made all the more clear when you say:

I enjoyed reading that thread. I think it's possibly a misnomer to call BM a nonlocal theory. Better perhaps to call it simply a global theory, because ….

Even Bohm himself made it clear that Local meant more than locality and that his BM was Non-Local! IMO your Global is nothing more than a restatement of Non-Local BM.

Finally you claim the correlations defined by QM are local because as you say:

Are they any more mysterious than the correlation between polarizer and analyzer in a standard polariscopic setup? I don't think so.

That can only mean you do not consider “polariscopic” results “mystic” or “mysterious” but "Local". Thus you should be able to explain the results for 200 photons sent through different configurations of H (horizontal) D (diagonal) and V (vertical) polar filters.
H => 100 pass
V => 100 pass
D => 100 pass
HV => Zero Pass
HDV => 25 Pass
HD => 50 Pass
If these results are not mysterious to you then you should be able to provide a detailed Bell Local (local and realistic), description that specifically describes what is unique about the 25 photons that pass the HDV configuration as compared to the individual descriptions of the other 175 photons.

You and jambaugh both have enough information in this thread to make clear what LOCAL means wrt to Bell, and that it does not just mean locality! At least well enough to understand that only Non-Local descriptions can resolve these polar filter results. If solved in Local terms it would confirm Local Realism not your non-local BM.

There is nothing more I can add to help you know what Local means, so I will unsubscribe from this thread. It is up to you to understand what real scientist mean by Local, until you do you cannot understand Bell, and your in no position to critique Bell.

 

[ThomasT]

That is just plain false, QM does not match the observed results by 1/2 ...

That isn't what P(A) = 1/2 and P(B) = 1/2 means. What P(A) = 1/2 and P(B) = 1/2 means is that for N emissions, then N/2 detections will be recorded at A and N/2 detections will be recorded at B.

Anyway, whether you think so or not, P(A) = P(B) = 1/2 is an expression of the qm prediction for individual detection in a standard EPR-Bell test. It's an expression of the randomness of the emissions.

At the outset of a standard optical Bell test some runs are made with no filters in place. Randomness of the emitted light is assumed. The results of these initial runs, the rates of individual detection at A and B, establish the maximum rate of detection at A and B for this setup. Assuming ideal efficiency, then all of the photons that could possibly be produced per unit of time are produced.

Then the polarizers are positioned, and the rate of detection falls to 1/2 the rate of detection per unit of time without polarizers. If the rates remain constant for many filter settings, then rotational invariance is assumed, the assumption of emission randomness is retained, and with the addition of some coincidence circuitry, then things are in place to do a standard EPR-Bell experiment.

Keep in mind that the emission process hasn't been changed with the addition of the polarizing filters, so we can assume that the same amount of light is emitted per unit of time with the polarizers as was emitted without the polarizers. But, as has been noted, with the polarizers in place only half of the emissions are detected at either A or B. No matter how the polarizer at A is oriented, no matter how the polarizer at B is oriented, no matter how the polarizers at A and B are oriented with respect to each other, the rate of detection at A and the rate of detection at B remain the same and equal to each other, and the sequences of detection attributes in the data streams remain random, during each and every run.

Some think that it's this randomness wrt individual detection that renders any possible nonlocality undetectable and therefore physically meaningless. Of course there's also the possibility that nonlocality simply doesn't exist in nature.

One can refer to any of the interpretations of quantum theory as local or nonlocal, but it really doesn't matter, because it's just a matter of taste.

I choose to call qm a local theory, because the assumption has always been that nature is local and there's no evidence to suggest that it isn't, and the uniquely quantum mechanical constructs tell us nothing about whether nature is local or nonlocal.

Finally you claim the correlations defined by QM are local because as you say:

Are they any more mysterious than the correlation between polarizer and analyzer in a standard polariscopic setup? I don't think so.

That can only mean you do not consider “polariscopic” results “mystic” or “mysterious” but "Local".

Or, it might mean that I consider both to be somewhat mysterious. But the thing about a standard classical polariscopic setup is that it appeals to my physical intuition in a more straightforward and clearcut way in displaying an apparently obvious locality than an optical Bell test setup does.

 

[RandallB]

... it's just a matter of taste.
I choose to call qm a local theory, ...
Or, it might mean that I consider both to be somewhat mysterious.

The terms Local and Non-Local are DEFINED especially wrt what they mean relative to Bell and which theories are Local (LR) or Non-Local (all others).
You do not get to “choose” whatever might appeal to you!

And you “might mean both are considered somewhat mysterious”
Wow if you’re that sure about what to have for dinner you’re going to starve!
Rather than insist you know something others don’t understand, you might want to actually be sure you know what you mean before sticking you two cents in.

I’m not surprised vanesch got tired of this stuff when folks refuse to learn the correct definitions of terms and how to use them when discussing with others.
I’ll double check to be sure the unsubscribe from this thread works this time, this is really rather pointless.