Is action at a distance possible as envisaged by the EPR Paradox.

[RUTA]

Do you mean his 21 papers on arXiv.org? There is no obligation for http://en.wikipedia.org/wiki/ArXiv#Peer_review", and only 2 are peer reviewed, and that was more than 10 years ago, and I can’t tell about the legitimacy of these two:

http://arxiv.org/abs/quant-ph/0008121"
Journal reference: Physics Essays 5(2) 226-234 (1992)

http://arxiv.org/abs/quant-ph/9711013"
Journal reference: Found. Phys. Lett. 12(5) 441-453 (1999)

But if you watch the whole video, you don’t need to be a professor to draw the conclusion I did, and I’m 100% - he IS a crackpot.

Do you really think a serious scientist would have a homepage named Non-loco Physics (loco means crazy in Spanish) = Non-crazy Physics. This can only be interpreted two ways; either Kracklauer thinks physics in general should be considered "loco" – or he acting preemptive to his own wild ideas. None is appealing...

How big is the chance that a great a healthy scientist has links to papers titled "Complementarity or Schizophrenia: is Probability in Quantum Mechanics Information or Onta?" ... ??

The man is a BIG joke, watch the video and have fun...

Are you talking about A.F. Kracklauer, "Is 'entanglement' always entangled?" J. Opt. B: Quantum Semiclass. Opt. 4 (2002), S121-S126? I met him at a conference some years ago and he presented what he claimed was the "proper" statistics for QM. In his approach, there was no need for non-locality or non-separability. After the conference, I found the faulty assumption in his approach -- his statistics assumes that knowledge of detector settings is available at both detection sites. I wrote him a detailed email explaining that experiments change polarization settings at very high frequencies precisely so info about Alice's detector settings is not available to Bob and vice versa. He became very upset and told me I didn't know what I was talking about. I don't know what else to do to help him and we haven't been in contact since.

 

[DevilsAvocado]

Are you talking about A.F. Kracklauer, "Is 'entanglement' always entangled?" J. Opt. B: Quantum Semiclass. Opt. 4 (2002), S121-S126? I met him at a conference some years ago and he presented what he claimed was the "proper" statistics for QM. In his approach, there was no need for non-locality or non-separability. After the conference, I found the faulty assumption in his approach -- his statistics assumes that knowledge of detector settings is available at both detection sites. I wrote him a detailed email explaining that experiments change polarization settings at very high frequencies precisely so info about Alice's detector settings is not available to Bob and vice versa. He became very upset and told me I didn't know what I was talking about. I don't know what else to do to help him and we haven't been in contact since.

Hehe! Sounds very much like "my" Crackpot Kracklauer!

This is getting better and better. The world is full of weird surprises. One thing that’s baffles me – how can a man with this much mathematical skill still draw completely illogical conclusions...? The only reasonable conclusion is that he knows what he’s doing – and he does it on purpose... You can’t be completely mad and solve this kind of equations, can you??

(Did you see https://www.physicsforums.com/showthread.php?p=2766674#2766674"?)


P.S. I will be surprised if billschnieder ever shows up in this thread again.

 

[RUTA]

(Did you see https://www.physicsforums.com/showthread.php?p=2766674#2766674"?)

No, that's the first I've seen it. That is the guy I met and tried to educate. I haven't seen any of his recent stuff, but given my past experience with him, it's probably not worth the time.

 

[DevilsAvocado]

... it's probably not worth the time.

Okay, I understand you completely.

RUTA, I think it would be of value (for any 'doubtful' reader) if you, as legitimate professor in physics, could confirm my conclusion that; Kracklauer cannot be using Bell inequalities to prove that he has found a working classical local realistic solution to EPR-Bell – and at the same time publish a paper where he claims to have proven that Bell inequalities are wrong from the very first assumption.

I’m only a layman, but even I understand that this is a complete crazy Catch-22, that it cannot be regarded as serious in any way.

 

[billschnieder]

Conditional probabilities in the integral on the right side of the equation, a marginal probability on the left.
...
It's true that you can interpret the left side as a conditional probability conditioned on a and b

So then your answer is that the left hand side of Bell's equation (2) is conditional with respect to (a,b) but marginal with respect to λ. And that outcome dependence between A and B exists when conditioned only on (a,b) but does not exist when conditioned on λ.

So then the expression P(AB|a,b) will accurately reflect what the probability Bell is calculating in equation (2) on the LHS? Yes or no.

And according to the chain rule of probability theory, the following expression is also true according to Bell's equation (2).

P(AB|a,b) = P(A|a,b)P(A|a,b,B)

Yes or no.

Please, note I am trying to engage in a precise discussions so don't assume you know where I am going with this and give me a preemptive response. A simple yes or no is sufficient here.

 

[DevilsAvocado]

billschnieder, please stop polluting this thread with CRACKPOT THEORIES, read https://www.physicsforums.com/showthread.php?p=2766674#post2766674".

 

[ajw1]

Do you mean his 21 papers on arXiv.org? There is no obligation for http://en.wikipedia.org/wiki/ArXiv#Peer_review", and only 2 are peer reviewed, and that was more than 10 years ago, and I can’t tell about the legitimacy of these two:

On the http://www.nonloco-physics.000freehosting.com/#personalia"I see about 25 publications in peer reviewed magazines (not counting the ones planned to be published), the last few being in 2007. I would say a little modesty would be in place.

 

[DevilsAvocado]

I see about 25 publications in peer reviewed magazines

Please, show me one paper from Kracklauer published outside Non-loco Physics and peer reviewed in a reputable scientific magazine after 1999?

 

[billschnieder]

Please, show me one paper from Kracklauer published outside Non-loco Physics and peer reviewed in a reputable scientific magazine after 1999?

Devil,
I was surprised not so see flashing and blinking animation reminiscent of 1995's internet in the above post of yours, check your calendar, it is 2010 not 1999. It is now possible to just type a name in scholar.google.com and verify what awj1 said above. BTW, you could have simply asked I would have given you the list of people who have influenced my approach to Bell.

Initially I thought I would just ignore you but then again by directly challenging you, you might benefit something from it and grow up from the dated distracting gifs and animations your posts are so infamous for.

Oh by the way, do you esteem yourself more wise and knowledgeable than the folks here, to the extent that you think they are unable to think for themselves, and need your advice on when to pay attention to what I say or not?

 

[ThomasT]

One thing that’s baffles me – how can a man with this much mathematical skill still draw completely illogical conclusions...?

Maybe they're not illogical. Maybe his premises are wrong. Or maybe some of his conclusions are illogical. Or maybe not. Since I haven't read his papers it's, as they say, too early (for me) to tell.

In any case, thanks for the resource. He has peer reviewed publications in several well respected journals. Even if his approach or conclusions turn out to be wrong, there is the benefit of his, from what I've seen so far, clear writing style. And of course there are his translations of some real classics in the physics literature. Definitely recommended reading.

So far, he doesn't seem like a crackpot. But I'll grant you that in the video he did seem a bit, er, scattered (but considering the obvious time constraint, his behavior didn't seem weird or anything). Nevertheless, his credentials appear to exceed any of the contributors to this thread.

So, again, thank you DA.

Edit:

Please, show me one paper from Kracklauer published outside Non-loco Physics and peer reviewed in a reputable scientific magazine after 1999?

There appear to be several.

 

[ThomasT]

... his statistics assumes that knowledge of detector settings is available at both detection sites.

This 'global' knowledge is available via the data processing and analysis. Isn't it?

I wrote him a detailed email explaining that experiments change polarization settings at very high frequencies precisely so info about Alice's detector settings is not available to Bob and vice versa.

While it's true that the settings are changed rapidly and randomly, it's also true that for any given time-matched pair of detection attributes there's an associated pair of polarizer settings. The statistics associated with any given run would include all of that. Wouldn't they?

I've only just glanced at the paper so far. If you can point out where his error appears, that would be appreciated.

 

[ThomasT]

It's {the data matching} based on the assumption from quantum mechanics that entangled particles are both created at the same position and time ...

Ok.

... but that doesn't mean that it's assumed that correlations in measurements of the two particles can be explained by local hidden variables given to them by the source.

I agree. The relationship between the two particles isn't, strictly speaking, a 'local' hidden variable. It's a parameter that emerges, and is only relevant, in the joint context. It doesn't determine individual measurement probabilities. And yet, isn't Bell's (2) requiring that the joint probability be modeled as the product of the two individual probabilities?

If by "a locally produced relationship" you mean local hidden variables, then no, the fact that the statistics violate Bell's inequalities show that this cannot be the explanation.

I agree, per above. But the root cause of the relationship can be assumed to be a local common source.

The local hidden variable in any trial is the randomly varying (from trial to trial) polarization angle that, presumably, would, if known, allow precise predictions of individual results. Qm says, in effect, that this local hidden variable is irrelevant wrt determining joint results -- that it is, rather, the unvarying relationship between counter-propagating disturbances emitted during the same atomic transition due to the conservation of angular momentum that determines joint results (re, eg., Clauser-Aspect type setups). This is just an interpretation of course, but it doesn't contradict anything in the qm treatment. And it's suggested that the attribution of, and subsequent projection along, a 'principle' axis given a qualitative result at one end or the other is compatible with the assumptions of locality and predetermination (albeit not separable) regarding the jointly measured underlying parameter. Why does the cos^2 theta rule following the attribution of the principle axis wrt a detection attribute work? Because the local hidden variable (as differentiated from the global parameter) can be any polarization angle. There are three vectors involved, call them, V1, V2, and V3, an optical vector and two unit vectors. They can be ordered in any way. One, the optical vector, is undetermined but assumed to be continuous between the two unit vectors. So, it seems logical to me, and compatible with the idea that everything is evolving according to the principle of locality, that the joint detection rate would be described by the cos^2 of the angular difference between the two unit vectors. As, I've said before, it's just accepted optics. And, because it's accepted optics, this is why the qm treatment for these types of setups is evaluated using Malus Law. I don't think that Bell's analysis rules this out, but rather that it's saying something about how this situation can be modeled. And, wrt that, Bell was correct.

The equation (2) was based on the assumption of causal independence between the two particles (i.e measuring one does not affect the other), which was expressed as a condition saying they're statistically independent conditioned on the hidden variables L ...

I agree. The equation says that the two particles (ie., the sets of detection attributes denoted by A and B) are statistically independent. In which case, the locality condition (separability of the joint state) is clearly formulated, but simply doesn't fit the experimental situation which, per se, doesn't require, or indicate in its evolution, the presence of nonlocal or ftl 'communication' between anything. So, we have a situation in which the purported independence between A and B is violated by the experimental design and realization which are entirely compatible with the assumption of locality. In other words, the fact that Bell's lhv form models statistical independence supercedes it's purported modelling of locality.

... but the equation is consistent with the idea that P(AB) can be different from P(A)*P(B).

Not sure what you mean.

 

[ThomasT]

DrC, you might have missed this. So, I'm posting it again. You've been asked to look at and comment on some LR models, and have refused to do so because they reproduce the qm predictions. This doesn't make sense to me, so if you would clarify the following, then maybe we might proceed. Thanks.

Here is the issue: I demand of any realist that a suitable dataset of values at three simultaneous settings (a b c) be presented for examination. That is in fact the realism requirement, and fully follows EPR's definition regarding elements of reality. Failure to do this with a dataset which matches QM expectation values constitutes the Bell program. Clearly, Bell (2) has only a and b, and lacks c. Therefore Bell (2) is insufficient to achieve the Bell result.

 

[DrChinese]

DrC, you might have missed this. So, I'm posting it again. You've been asked to look at and comment on some LR models, and have refused to do so because they reproduce the qm predictions. This doesn't make sense to me, so if you would clarify the following, then maybe we might proceed. Thanks.

I stated:

i) I demand of any realist that a suitable dataset of values at three simultaneous settings (a b c) be presented for examination. That is in fact the realism requirement, and fully follows EPR's definition regarding elements of reality. Failure to do this with a dataset which matches QM expectation values constitutes the Bell program.

ii) Clearly, Bell (2) has only a and b, and lacks c. Therefore Bell (2) is insufficient to achieve the Bell result.

------------------
So to expand on these:

i) There are a number of papers that "purport" to provide local realistic models. But they do not provide datasets (with 3 angle settings) which match the QM expectation values. That is to be expected, because Bell discovered that there are no such datasets. Why is a dataset important? Because it was known already that datasets with 2 angle settings were possible. In fact, that was more or less one of the EPR conclusions although they did not really specify that single point. What they did specify was that the existing (at that time) QM program could be made "more complete" with additional parameters, yet to be discovered.

So local realistic theories with 2 simultaneous settings are missing the boat, precisely because they describe something which is not prohibited by Bell. And if they did offer the ability to provide a 3 setting dataset, they would simply provide it and Bell would be overturned. So I don't really need to read and de-bunk each purported solution until and unless a dataset can be provided.

In the case of the De Raedt local realistic computer simulation, on the other hand, such a dataset is provided. So naturally I DO take it seriously and am actively involved in working with a respected member of their team to understand their model and its characteristics. Keep in mind that it is a simulation, not a true physical model. However, the success of their model would open the door to a physical model - if it can survive questions that are inevitable.

ii) One of the recent questions on this board concerns whether Bell (2) is a sufficient assumption to achive the main result. You can see for yourself - as can anyone who will simply look - that it does not involve 3 settings, but instead only 2. The Bell program requires the assumption of at least existence of 3 simultaneous "elements of reality". In the EPR program, there was only 1 (let's call it a), because that was all that could be predicted with certainty. But they said in their closing papragraphs that it was reasonable to consider that any element of reality individually should reasonably be considered to exist independent of actual observation. So this is the counterfactual case: b, c... etc. They needed this because it was essential to their claim that QM was incomplete. Bell accepted the "challenge" and considered a, b and c, achieving his now famous result. But you cannot get it - as far as I have seen - with just (2). You need after (14) too.

 

[billschnieder]

DrC,
Take a look at my last post in the thread "Understanding Bell's logic (post #113)" in which I presented a simplified version of JesseM's scratch-lotto card example, which is essentially a copy of Mermin's example.

Is it still your believe that an instruction set explanation of it is impossible? Will an instruction-set explanation of that example qualify as a "dataset" that you keep asking for?

 

[DrChinese]

DrC,
Take a look at my last post in the thread "Understanding Bell's logic (post #113)" in which I presented a simplified version of JesseM's scratch-lotto card example, which is essentially a copy of Mermin's example.

Is it still your believe that an instruction set explanation of it is impossible? Will an instruction-set explanation of that example qualify as a "dataset" that you keep asking for?

Yes, Bill, I think that works for me. I looked over the example and it looks pretty good. That is definitely the kind of example that clarifies so that definitions are not standing in the way of finding a common ground.

 

[DevilsAvocado]

He has peer reviewed publications in several well respected journals.

Could you please show me one title, link, or paper-id?

So far, he doesn't seem like a crackpot. But I'll grant you that in the video he did seem a bit, er, scattered (but considering the obvious time constraint, his behavior didn't seem weird or anything). Nevertheless, his credentials appear to exceed any of the contributors to this thread.

ThomasT, please tell me you are joking, right? A bit "scattered"?? This is some of the worst cranky stuff I have ever seen. The first 4 min of the video Crackpot Kracklauer dismisses QM and states that the Heisenberg uncertainty principle is wrong! According to Crackpot Kracklauer at 03:20.

"The reason they don’t commute is not because someone has imposed the Heisenberg uncertainty relationship on them. In fact, the reason they don’t commute is purely geometry. The ah eh the the the structure of 'Qubit Space' in terms of polarization was worked out by... by... what’s his name... an Englishman ...in 1856... Stokes's! Fifty years before Pauli was born even!"​

Crackpot Kracklauer is now talking about one of the pioneers of quantum physics and a Nobel laureate in Physics http://en.wikipedia.org/wiki/Wolfgang_Pauli" was a QM pioneer and a Nobel laureate in Physics.

Don’t you see the pure madness in this!? Crackpot Kracklauer tries to give picture that QM is completely wrong, and the big questions were already solved fifty years before anyone has ever heard the word quantum theory?? This is insane. He runs his own private mad war against QM.

And to be perfectly clear to the "casual reader"; IF Crackpot Kracklauer is right and QM is wrong, then right now your hard disk drive in your own computer will have 3 times lesser capacity! Since QM http://en.wikipedia.org/wiki/Giant_magnetoresistance" is used by ALL manufacturers to increase HDD capacity.

Furthermore, there’s a whole bunch of gadgets you use every day that will stop working if Crackpot Kracklauer is anywhere near right. But don’t worry, Crackpot Kracklauer dead wrong and QM is the most precise theory we got. Period.

So, Crackpot Kracklauer is just too much, and I will never back off from this, never. Supporting Crackpot Kracklauer must be against all and everything in https://www.physicsforums.com/showthread.php?t=5374" (my emphasis):

Overly Speculative Posts:
One of the main goals of PF is to help students learn the current status of physics as practiced by the scientific community; accordingly, Physicsforums.com strives to maintain high standards of academic integrity. There are many open questions in physics, and we welcome discussion on those subjects provided the discussion remains intellectually sound. It is against our Posting Guidelines to discuss, in most of the PF forums or in blogs, new or non-mainstream theories or ideas that have not been published in professional peer-reviewed journals or are not part of current professional mainstream scientific discussion. Personal theories/Independent Research may be submitted to our Independent Research Forum, provided they meet our Independent Research Guidelines; Personal theories posted elsewhere will be deleted. Poorly formulated personal theories, unfounded challenges of mainstream science, and overt crackpottery will not be tolerated anywhere on the site. Linking to obviously "crank" or "crackpot" sites is prohibited.

In any case, thanks for the resource.

You are welcome.

 

[DevilsAvocado]

... BTW, you could have simply asked I would have given you the list of people who have influenced my approach to Bell.

So I’m asking you very friendly now: Please show me one reputable scientist who speculates around the possibilities that John Stewart Bell made a terrible mistake when he used a comma instead of vertical bar, in equation (2), and therefore Bell's Theorem is all wrong from start. Please, just one trustworthy scientist.

I will apologize sincerely if you prove me wrong.

 

[billschnieder]

So I’m asking you very friendly now: Please show me one reputable scientist who speculates around the possibilities that John Stewart Bell made a terrible mistake when he used a comma instead of vertical bar, in equation (2), and therefore Bell's Theorem is all wrong from start. Please, just one trustworthy scientist.

I will apologize sincerely if you prove me wrong.

Provide a quote from the article where you think Kracklauer made such a statement, and I will use the same quote to prove to the whole world just why it is you who has issues understanding simple English. So the the ball is in your court. I hope you will keep your honor by appologizing sincerely when this is all over.

I'm waiting!

 

[DevilsAvocado]

Provide a quote from the article where you think Kracklauer made such a statement

I hope there’s nothing wrong with your glasses? Because it’s right in front of your nose in https://www.physicsforums.com/showpost.php?p=2766674&postcount=806":

(I’ll make it a little bigger for you this time)

IX. CONCLUSIONS
The points made above offer several explanations for the observation noted in the introduction, that BELL’s Ansatz, Eq. (1), cannot be found in treatises on statistics and probability. To begin, there is misleading notation; BELL USED A COMMA to separate the independent arguments, whereas ‘hidden’ variables, by definition would be conditioning parameters, and, as such, in the notation customary in works on probability, are separated from independent variables by a VERTICAL BAR. This malapropos TURN OF THE PEN appears to have been an important facilitating element in the general MISCONSTRUAL OF BELL’S ANALYSIS. Once this defect is corrected, it is a short leap to the understanding of the necessity for applying BAYES’ formula; a leap apparently made first by JAYNES.

The pure fact that you are continually supporting Crackpot Kracklauer proves, without any doubt, that I was perfectly correct from the start. I gave you a fair chance to solve this in a civilized manner – you didn’t take it.

If you continue to promote Crackpot Kracklauer’s completely crazy theories, I will report you. I don’t even have to "prove" anything – Crackpot Kracklauer is, by his very own definition, an independent researcher. His crazy "stuff" is only allowed in the Independent Research Forum, provided he meets the Independent Research Guidelines, which he will never do. End of story.

I do hope you are capable of reading and understanding the https://www.physicsforums.com/showthread.php?t=5374"?

Make your choice.

 

[billschnieder]

Remember, the phrases you are trying to prove against Kracklauer are the following, in your own words:

WOW! Now we know why Bell is wrong! He used a comma instead of vertical bar! THIS IS GROUNDBREAKING NEWS!

John Stewart Bell made a terrible mistake when he used a comma instead of vertical bar, in equation (2), and therefore Bell's Theorem is all wrong from start.

You said twice, that Kracklauer claims Bell's Theorem is all wrong because he used a comma instead of a vertical bar. So let us examine your so-called proof.

IX. CONCLUSIONS
The points made above offer several explanations for the observation noted in the introduction, that Bell’s Ansatz, Eq. (1), cannot be found in treatises on statistics and probability.
To begin, there is misleading notation; Bell used a comma to separate the independent arguments, whereas ‘hidden’ variables, by definition would be conditioning parameters, and, as such, in the notation customary in works on probability, are separated from independent variables by a vertical bar.
This malapropos turn of the pen appears to have been an important facilitating element in the general misconstrual of Bell's analysis. Once this defect is corrected, it is a short leap to the understanding of the necessity for applying bayes’ formula; a leap apparently made first by Jaynes.

Clearly, from the above, any layman capable of understanding English can figure out that according to Kracklauer, the non-standard notation used by Bell, has facilitated a general misunderstanding of Bell's analysis. Was this quote supposed to prove that Kracklauer claims Bell's inequalities are wrong because he used a comma instead of a vertical bar?

1) Did Bell use non-standard notation? Yes
2) Does standard notation use a vertical bar instead of a comma when expressing conditional probability? Yes
3) Is it reasonable to suggest that the use of non-standard notation leads to misunderstanding? Yes.

I do hope you are capable of reading and understanding the https://www.physicsforums.com/showthread.php?t=5374"?

Let us see what the document you linked to says:

When posting a new topic do not use the CAPS lock (all-CAPS), bold, oversized, or brightly colored fonts, or any combination thereof. They are hard to read and are considered yelling. When replying in an existing topic it is fine to use CAPS or bold to highlight main points.

So keep looking and produce the quote where Kracklauer claims Bell's inequalities are wrong because he used a comma instead of a vertical bar.

 

[DevilsAvocado]

Remember, the phrases you are trying to prove against Kracklauer are the following

Hahahah! I’m laughing my pants off! (<-- Note: BOLD! )

billschnieder, you must be the most "peculiar" guy I’ve ever seen on PF. Don’t you understand that you are helping me to prove beyond any doubts – that your one and only source for all this extensive cranky-probability-mess, that you have practiced all over the place, is Crackpot Kracklauer!

Don’t you understand this?? Is this really so hard??

And this strategic blunder is nothing more than laughable (and I do feel sorry for you):

1) Did Bell use non-standard notation? Yes
2) Does standard notation use a vertical bar instead of a comma when expressing conditional probability? Yes
3) Is it reasonable to suggest that the use of non-standard notation leads to misunderstanding? Yes.

Here you are actually verifying that all my claims were correct from the very start.

I don’t care if you spend 1000 "probability-enigma-posts" in threads like "Trying to understand this and that", but if you continue in this thread, I will report you, guaranteed.

By the way: Why don’t you report me for using CAPS lock (all-CAPS) + bold + oversized?? It’ll be fun! Ever heard of the boomerang??

Thanks for the laughs, take care.

 

[billschnieder]

DevilsAvocado,
Did you find the quote yet where you say Kracklauer claims Bell's inequalities are wrong because he used a comma instead of a vertical bar? Or was it just as untrue as the claim that Kracklauer has only two peer reviewed articles published before 1999 and none after.

 

[billschnieder]

Yes, that is the full quote. My point is that EPR sets up a definition of realism which is NOT limited to what can be experimentally demonstrated. That 2 or more elements of reality - a, b and c were used by Bell - should be reasonably expected to exist simultaneously. Bell and Aspect have shown us that this view (EPR realism) is theorically and experimentally invalid.

DrC,
I disagree with your interpretation of the EPR quote, which I parse below. Not only is theEPR definition not limited to what can be experimentally demonstrated, but it is also not limited to what can be predicted as explained below.

"
1) One could object to this conclusion on the grounds that our criterion of reality is not sufficiently restrictive.
2) Indeed, one would not arrive at our conclusion if one insisted that two or more physical quantities can be regarded as simultaneous elements of reality only when they can be simultaneously measured or predicted.
3) On this point of view, since either one or the other, but not both simultaneously, of the quantities P and Q can be predicted, they are not simulataneously real. This makes the reality of P and Q depend upon the process of measurement carried out on the first system, which does not disturb the second system in any way.
4) No reasonable definition of reality could be expected to permit this."

1) Here they lay out a possible objection to their criterion for reality, the one that they should have restricted it more as outlined in point (2).
2) EPR argue that, if we insist that "simultaneous elements of reality" is taken to mean elements of reality must be simultaneously measured or predicted, then their conclusion can not be reached. Therefore, according to EPR, their definition of "simultaneous elements of reality" does not mean they must be simultaneously measured or predicted.
3) In support of the above, EPR lay out a situation in which it is not possible to simultaneously measure or predict P and Q, and use it to show that if we insist that "simultaneous elements of reality" means they must simultaneously be measurable or predictable, then under this more restrictive definition (which is not the one they are proposing), the reality of a remote station can be changed by a measurement on a local station.
4) They then conclude that such a more restrictive definition is therefore not reasonable. According to EPR, therefore, any definition of reality which insists that elements of reality are only simultaneously real if they can be simultaneously measured, is a different definition from the EPR definition.

 

[DrChinese]

Did you find the quote yet where you say Kracklauer claims Bell's inequalities are wrong because he used a comma instead of a vertical bar?

And I will tell you again, as I have said many times before, that trying to read Bell on a literal or character for character basis is absurd. You don't need Bell (2) to get to his result, there are other ways too. That is simply a single way to express one of the assumptions of local realism. If you substitute your own, you will still arrive at his conclusion. Ergo, attacking the specific form is a waste of time.

The correct way to read Bell is to consider his audience. He knew they would follow his thinking in their own manner. The key was that any reasonable set of local realistic assumptions - again supply your own - leads right back to the Bell conclusion: QM and LR are not compatible.

I have to tell you that Devil's quote about the "misleading" notation is pretty funny. I don't think I have EVER heard an attack like that from a professional about another professional. And as I say, it is ridiculous to boot!

 

[DrChinese]

...

1) Here they lay out a possible objection to their criterion for reality, the one that they should have restricted it more as outlined in point (2).
2) EPR argue that, if we insist that "simultaneous elements of reality" is taken to mean elements of reality must be simultaneously measured or predicted, then their conclusion can not be reached. Therefore, according to EPR, their definition of "simultaneous elements of reality" does not mean they must be simultaneously measured or predicted.
3) In support of the above, EPR lay out a situation in which it is not possible to simultaneously measure or predict P and Q, and use it to show that if we insist that "simultaneous elements of reality" means they must simultaneously be measurable or predictable, then under this more restrictive definition (which is not the one they are proposing), the reality of a remote station can be changed by a measurement on a local station.
4) They then conclude that such a more restrictive definition is therefore not reasonable. According to EPR, therefore, any definition of reality which insists that elements of reality are only simultaneously real if they can be simultaneously measured, is a different definition from the EPR definition.

Yes, I quite agree with your parsing of EPR (as I said previously). And as I said, they assert that for their elements of reality to stand - a, b and c for example - they do not need to be simultaneously predictable with certainty. Bell accepted this definition, and I do too.

So then Bell went to work on a, b and c, and discovered that IF they existed simultaneously - as EPR asserts - then they could NOT match the QM expectation values. Ergo, either the EPR assertion is wrong OR there is spooky action at a distance. Take your pick!

 

[billschnieder]

So then Bell went to work on a, b and c, and discovered that IF they existed simultaneously - as EPR asserts - then they could NOT match the QM expectation values. Ergo, either the EPR assertion is wrong OR there is spooky action at a distance. Take your pick!

But you are drawing the wrong conclusion. EPR did not say Bell's a, b, c must be simultaneous elements of reality. So I do not see which EPR assertion is claimed to be wrong here?

 

[DevilsAvocado]

And I will tell you again, as I have said many times before, that trying to read Bell on a literal or character for character basis is absurd. You don't need Bell (2) to get to his result, there are other ways too. That is simply a single way to express one of the assumptions of local realism. If you substitute your own, you will still arrive at his conclusion. Ergo, attacking the specific form is a waste of time.

Thanks DrC, very well formulated words.

 

[my_wan]

Yes, I quite agree with your parsing of EPR (as I said previously). And as I said, they assert that for their elements of reality to stand - a, b and c for example - they do not need to be simultaneously predictable with certainty. Bell accepted this definition, and I do too.

So then Bell went to work on a, b and c, and discovered that IF they existed simultaneously - as EPR asserts - then they could NOT match the QM expectation values. Ergo, either the EPR assertion is wrong OR there is spooky action at a distance. Take your pick!

Put this way I have to agree. The operational definition of realism as provided by EPR is fatally flawed beyond any reasonable doubt. I see this as an indication that observables are not non-degenerate. As such, the observables likely do, in a sense, lack a reality independent of the measurement. I don't see the generalization of this as a refutation of realism in general, nor that determinism is refuted. Though this, and other considerations, indicates that if elements of reality exist they are not directly accessible empirically and also most likely transfinite.

 

[zonde]

As to GHZ:

"Surprisingly, in 1989 it was shown by Greenberger, Horne and Zeilinger
(GHZ) that for certain three- and four-particle states a conflict with
local realism arises even for perfect correlations. That is, even for those cases
where, based on the measurement on N −1 of the particles, the result of the
measurement on particle N can be predicted with certainty. Local realism
and quantum mechanics here both make definite but completely opposite
predictions.

"To show how the quantum predictions of GHZ states are in stronger conflict
with local realism than the conflict for two-particle states as implied by Bell’s
inequalities, let us consider the following three-photon GHZ state:

"We now analyze the implications of these predictions from the point of
view of local realism. First, note that the predictions are independent of the
spatial separation of the photons and independent of the relative time order
of the measurements. Let us thus consider the experiment to be performed
such that the three measurements are performed simultaneously in a given
reference frame, say, for conceptual simplicity, in the reference frame of the
source. Thus we can employ the notion of Einstein locality, which implies
that no information can travel faster than the speed of light. Hence the
specific measurement result obtained for any photon must not depend on
which specific measurement is performed simultaneously on the other two
or on the outcome of these measurements. The only way then to explain
from a local realistic point of view the perfect correlations discussed above
is to assume that each photon carries elements of reality for both x and y
measurements considered and that these elements of reality determine the
specific individual measurement result. Calling these elements of reality...

"In the case of Bell’s inequalities for two photons the conflict between local
realism and quantum physics arises for statistical predictions of the theory;
but for three entangled particles the conflict arises even for the definite predictions."

Zeilinger talking about GHZ in:
http://www.drchinese.com/David/Bell-MultiPhotonGHZ.pdf

So GHZ does show that Local Realism makes specific predictions which are flat out contradicted by both QM and experiment.

I looked into experiments. Have to say that the one provided by unusualname was very helpful:

4 Particle GHZ violations of local realism were demonstrated back in 2003:
Violation of Local Realism by Four-Photon
Greenberger-Horne-Zeilinger Entanglement Phys. Rev. Lett. 91, 180401 (2003) [4 pages] [/url]

So as to what it demonstrates.
First of all it uses four modifications of experiment to demonstrate the point about LR.
Three experiments are used to make LR prediction for the fourth experiment.
That way you can't say that contradiction is achieved in single run.

Another thing is that as in any real experiment you don't have perfect result. So if you say that every single (4-fold coincidence) detection confirms QM and contradicts LR then in experiment we have situation like that:
"The experimental results in (f) are in agreement with the QM predictions (d) while in conflict with LR (e), with a visibility of 0.789+-0.012."
That means we have 90 detections out of every 100 that without any doubt confirm QM and 10 detections that without any doubt confirm LR.

That of course is not very serious interpretation of experimental results.

Next if we look at this sentence (from the quote you already provided):
"The only way then to explain from a local realistic point of view the perfect correlations discussed above is to assume that each photon carries elements of reality for both x and y measurements considered and that these elements of reality determine the specific individual measurement result."
First of all correlations are not perfect. If we compare visibility of HVVH and VHHV results they had around 0.98 visibility. Switching to L/R and H'/V' (+45°/-45°) base considerably reduced visibility i.e. around 0.80. So measurements in base that is incompatible with the base photons where created in are far from prefect correlations.
Second a local realistic point of view is not restricted to the point that each photon should carry all the relevant information.
For example, two photon combination can carry more information than simple sum of information from two single photons. That's because there is additional information in possible two photon configurations relative to each other.
So the point about "the only way" is not very serious.