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

[DrChinese]

I just did a miraculous scientific discovery! I made my own little "theory" by assigning Malus' to both (not entangled) Alice & Bob, and guess what?? IT DID PROVIDE ME WITH A DATASET! OH MY GOD!

[B]Angle	Malus'	Alice	Bob[/B]
------------------------------
0º	100%	111111	111111
22.5º	85%	111110	111110
45º	50%	111000	111000
67.5º	15%	100000	100000
90º	0%	000000	000000

Cool. I wonder why some people have such a hard time of it. Heh.

 

[ThomasT]

I just did a miraculous scientific discovery! I made my own little "theory" by assigning Malus' to both (not entangled) Alice & Bob, and guess what?? IT DID PROVIDE ME WITH A DATASET! OH MY GOD!

[B]Angle	Malus'	Alice	Bob[/B]
------------------------------
0º	100%	111111	111111
22.5º	85%	111110	111110
45º	50%	111000	111000
67.5º	15%	100000	100000
90º	0%	000000	000000

Why this doesn't work has been quite extensively discussed in this thread. This is a misapplication of Malus Law. It doesn't predict individual results. Attributing specific values to polarization vectors causes Malus Law to break down.

LR and QM models of entanglement don't predict datasets. They predict rates of detection.

Entanglement stats are produced by entanglement experiments (or valid simulations). This is the only source for datasets that might be used to evaluate the relative accuracy of competing models.

 

[nismaratwork]

Why this doesn't work has been quite extensively discussed in this thread. This is a misapplication of Malus Law. It doesn't predict individual results. Attributing specific values to polarization vectors causes Malus Law to break down.

LR and QM models of entanglement don't predict datasets. They predict rates of detection.

Entanglement stats are produced by entanglement experiments (or valid simulations). This is the only source for datasets that might be used to evaluate the relative accuracy of competing models.

How on Earth does Malus' Law apply to this in the slightest?

 

[DrChinese]

LR and QM models of entanglement don't predict datasets. They predict rates of detection.

I think DevilsAvocado has proven you wrong. Cause there is one for us to look at right there on the page. I see it. If that model is not a QM consistent dataset, perhaps you will point out the elements which fail.

 

[DevilsAvocado]

Why this doesn't work has been quite extensively discussed in this thread. This is a misapplication of Malus Law. It doesn't predict individual results. Attributing specific values to polarization vectors causes Malus Law to break down.

I don’t agree. Yes, Malus' gives a percentage for the probability at a certain angle, but does this fact make it impossible to predict individual results? Definitely no, it’s possible indeed to predict the individual results.

For the first angle 0º we only 1 possible combination, 100% all the time:
111111

For the second angle 22.5º we have 6 different combinations:
111110
111101
111011
110111
101111
011111


For the third angle 45º we have 20 different combinations:
111000
110100
110010
110001
101100
101010
101001
100110
100101
100011
011100
011010
011001
010110
010101
010011
001110
001101
001011
000111

For the forth angle 67.5º we have the same combinations as for angle 22.5º, i.e. 6 different combinations.

For the fifth angle 90º we have the same combinations as for angle 0º, i.e. 1 combination.

This gives us a total of 1 x 6 x 20 x 6 x 1 = 720 combinations.

I know, and you know that it’s very possible to print these different combinations, and predict with 100% certainty every time we run this test, that one of the combinations will occur.

It’s like winning on the lottery every day!


(Maybe someone who is better in math than I am, could tell me if it’s just a fluke that 6! = 720 ??)

 

[DevilsAvocado]

Cool. I wonder why some people have such a hard time of it. Heh.

There are more things in heaven and earth, than are dreamt of in philosophy.

 

[DevilsAvocado]

How on Earth does Malus' Law apply to this in the slightest?

cos^2(a-b)

 

[nismaratwork]

cos^2(a-b)

I think you covered the relevance of how it doesn't interfere with the results a couple of posts ago.

 

[ThomasT]

LR and QM models of entanglement don't predict datasets. They predict rates of detection.

I think DevilsAvocado has proven you wrong. Cause there is one for us to look at right there on the page. I see it. If that model is not a QM consistent dataset, perhaps you will point out the elements which fail.

So, what are you saying DrC, that qm predicts the results of individual measurements? That's silly. Or do you just say these sorts of things to confuse people?

Your 'dataset' requirement for LR models is nonsense. It's nonsense, it has nothing to do with any of this. If you think it does, then write a paper on it and get it peer reviewed. Otherwise, stop presenting it in these forums.

And for DA's idea that specific values of polarization vectors are in one to one correspondence with experimental results -- I'm sorry but we have no way of knowing if that's the case.

So, I'll repeat MY mantra. LR and QM models of entanglement predict rates of coincidental detection. No more, and no less.

 

[DrChinese]

1. Your 'dataset' requirement for LR models is nonsense. It's nonsense, it has nothing to do with any of this. If you think it does, then write a paper on it and get it peer reviewed. Otherwise, stop presenting it in these forums.

2. So, I'll repeat MY mantra. LR and QM models of entanglement predict rates of coincidental detection. No more, and no less.

1. You can consider my dataset requirement more of a crackpot filter. And I think it's working!

2. Then perhaps you will show us your LR formula, and by the way, why don't you give us a sample dataset so we can see it in action. I will gladly do the same for QM's model.

 

[DevilsAvocado]

a crackpot filter. And I think it's working!

 

[DevilsAvocado]

And for DA's idea that specific values of polarization vectors are in one to one correspondence with experimental results -- I'm sorry but we have no way of knowing if that's the case.

So, I'll repeat MY mantra. LR and QM models of entanglement predict rates of coincidental detection. No more, and no less.

Okay, I’m not stubborn, running over people with my own little skewed view.

Let’s do it real simple:

[B]Angle	Alice	Bob[/B]
--------------------
0º	100%	100%
22.5º	85%	85%
45º	50%	50%
67.5º	15%	15%
90º	0%	0%

This is the "prediction rates of coincidental detection", or the correlation between Alice & Bob. Angle is the relative angle between Alice & Bob. And there are no individual results, just statistics.

Happy?

Now, please deliver your LR model and percentage for the correlation, as above.


P.S. Please, don’t forget to explain in detail how this will be achieved in the real world!

 

[ThomasT]

1. You can consider my dataset requirement more of a crackpot filter. And I think it's working!

Your dataset requirement is itself crackpotty. You're requiring models of entanglement to do something that they're not designed to do. To reiterate, neither LR nor QM models of entanglement predict datasets. They predict rates of detection.

In another recent thread you used your 'dataset requirement' to 'show' that LR models of individual results are incompatible with QM -- a 'result' which stands in direct contradiction to Bell. None of the other posters in that thread had any idea what you were talking about either.

2. Then perhaps you will show us your LR formula, and by the way, why don't you give us a sample dataset so we can see it in action.

You've been given the opportunity to look at and critique several purported LR models, but you've refused to do so. Maybe you can present an argument that they're not local or not realistic, or that they're neither. But you can't do it by requiring them to produce datasets, because they don't predict datasets -- any more than QM does. What they do is match the QM prediction regarding rate of coincidental detection.

I will gladly do the same for QM's model.

Well, that will be a neat trick, since afaik QM doesn't predict datasets, but only detection rates.

 

[ThomasT]

Now, please deliver your LR model and percentage for the correlation, as above.

There have been at least a couple, authored by working physicists, already presented in this thread.

P.S. Please, don’t forget to explain in detail how this will be achieved in the real world!

They predict the same results that QM does for applicable experiments. As I mentioned to DrC, you might present some reason(s) why they shouldn't be considered LR models.

 

[JesseM]

There have been at least a couple, authored by working physicists, already presented in this thread.

What posts are you referring to? Are you talking about models that exploit loopholes, or are you claiming there are local realist models that predict BI violations even in loophole-free experiments of the type imagined by Bell?

 

[DrChinese]

There have been at least a couple, authored by working physicists, already presented in this thread.

Let's see a peer reviewed reference when it comes to non-standard science. I missed any that meet that criteria.

 

[DevilsAvocado]

There have been at least a couple, authored by working physicists, already presented in this thread.

Oh yeah, could please give me a link, or are we exercising that famous swindlin' again?

Edit: I think I’ve found it:

... So, there's some room for speculation there (not that there's any way of definitively knowing whether a proposed, and viable, 'realistic' model of 'interim' photon behavior corresponds to reality). In connection with this, JenniT is developing an LR model in the thread on Bell's mathematics, and Qubix has provided a link to a proposed LR model by Joy Christian.

Okay, so JenniT (a PF user) is the "working physicists" + Joy Christian alias "Mr. Disproofs", who have no working LR model, but a http://arxiv.org/find/all/1/all:+AND+Joy+Christian/0/1/0/all/0/1"...?

Anyway, it isn't like these are easy question/considerations.

Well, this statement seems to be a contradiction to the first line in this post: "There have been at least a couple, authored by working physicists, already presented in this thread."

... Wrt to your exercises illustrating the difficulty of understanding the optical Bell test correlations in terms of specific polarization vectors -- yes, that is a problem. It's something that probably most, or maybe all, of the readers of this thread have worked through. It suggests a few possibilities: (1) the usual notion/'understanding' of polarization is incorrect or not a comprehensive physical description, (2) the usual notion/'understanding' of spin is incorrect or not a comprehensive physical description, (3) the concepts are being misapplied or inadequately/incorrectly modeled, (4) the experimental situation is being incorrectly modeled, (5) the dynamics of the reality underlying instrumental behavior is significantly different from our sensory reality/experience, (6) there is no reality underlying instrumental behavior or underlying our sensory reality/experience, etc., etc. My current personal favorites are (3) and (4), but, of course, that could change. Wrt fundamental physics, while there's room for speculation, one still has to base any speculations on well established physical laws and dynamical principles which are, necessarily, based on real physical evidence (ie. instrumental behavior, and our sensory experience, our sensory apprehension of 'reality' -- involving, and evolving according to, the scientific method of understanding).

A lot of personal speculations, but still no working LR model. If there is one, please provide the link.​

They predict the same results that QM does for applicable experiments.

Interesting, could you please describe where the "on/off button" for entangled/not entangled pairs is situated in your LR model? And how does it work?

I take it for granted that you are aware that not entangled pairs produce completely different statistics, and I want to know what your LRM has to say about that?

(If you refer to earlier posts without linking, I take it for granted you have no answer.)

 

[ThomasT]

There have been at least a couple, authored by working physicists, already presented in this thread.

Oh yeah, could please give me a link, or are we exercising that famous swindlin' again?

Swindle these:

Failure of Bell's Theorem and the Local Causality of the Entangled Photons
Joy Christian (Oxford)
http://arxiv.org/abs/1005.4932

Disproofs of Bell, GHZ, and Hardy Type Theorems and the Illusion of Entanglement
Joy Christian (Oxford)
http://arxiv.org/abs/0904.4259

Can Bell's Prescription for Physical Reality Be Considered Complete?
Joy Christian (Oxford)
http://arxiv.org/abs/0806.3078

Disproof of Bell's Theorem: Further Consolidations
Joy Christian (Perimeter and Oxford)
http://arxiv.org/abs/0707.1333

Disproof of Bell's Theorem: Reply to Critics
Joy Christian (Perimeter and Oxford)
http://arxiv.org/abs/quant-ph/0703244

Disproof of Bell's Theorem by Clifford Algebra Valued Local Variables
Joy Christian (Oxford)
http://arxiv.org/abs/quant-ph/0703179

Possible Experience: from Boole to Bell
K. Hess (Beckman Institute, Department of Electrical Engineering and Department of Physics, University of Illinois)
K Michielsen (Institute for Advanced Simulation, Julich Supercomputing Centre, Research Centre Julich)
H. De Raedt (Department of Applied Physics, Zernike Institute of Advanced Materials)
Published in: EPL, 87 (2009) 60007
http://arxiv.org/abs/0907.0767

Extended Boole-Bell inequalities applicable to quantum theory
H. De Raedt (Department of Applied Physics, Zernike Institute of Advanced Materials)
K. Hess (Beckman Institute, Department of Electrical Engineering and Department of Physics, University of Illinois)
K. Michielsen (Institute for Advanced Simulation, Julich Supercomputing Centre, Research Centre Julich)
http://arxiv.org/abs/0901.2546

Bell's Inequality: Physics meets Probability
Andrei Khrennikov (International Center for Mathematical Modelling in Physics and Cognitive Sciences, Linnaeus University)
http://arxiv.org/abs/0709.3909

A Mathematician's Viewpoint to Bell's theorem: In Memory of Walter Philipp
Andrei Khrennikov (International Center for Mathematical Modelling in Physics and Cognitive Sciences, Linnaeus University)
http://arxiv.org/abs/quant-ph/0612153

Quantum nonlocality or nonergodicity? A critical study of Bell's arguments
Andrei Khrennikov (International Center for Mathematical Modelling in Physics and Cognitive Sciences, Linnaeus University)
http://arxiv.org/abs/quant-ph/0512178

Quantum correlations from local amplitudes and the resolution of the Einstein-Podolsky-Rosen nonlocality puzzle
C. S. Unnikrishnan (Gravitation Group, Tata Institute of Fundamental Research)
http://arxiv.org/abs/quant-ph/0005103

There is no spooky action-at-a-distance in quantum correlations: Resolution of the EPR nonlocality puzzle
C. S. Unnikrishnan (Gravitation Group, Tata Institute of Fundamental Research)
http://arxiv.org/abs/quant-ph/0001112

Three-particle GHZ correlations without nonlocality
C. S. Unnikrishnan (Gravitation Group, Tata Institute of Fundamental Research)
http://arxiv.org/abs/quant-ph/0004089

Law of Malus and Photon-Photon Correlations: A Quasi-Deterministic Analyzer Model
Bill Dalton (SCSU)
http://arxiv.org/abs/quant-ph/0101127

Bell's inequality violation due to misidentification of spatially non stationary random processes
Journal-ref: Journal of Modern Optics, 2003, Vol. 50, No. 15-17, 2465-2474
Louis Sica (Naval Research Laboratory, Washington, D. C.)
http://arxiv.org/abs/quant-ph/0305071

Bell's inequalities I: An explanation for their experimental violation
Journal-ref: Optics Communications 170 (1999) 55-60
Louis Sica (Naval Research Laboratory, Washington, D. C.)
http://arxiv.org/abs/quant-ph/0101087

Bell's inequalities II: logical loophole in their interpretation
Journal-ref: Optics Communications 170 (1999) 61-66
Louis Sica (Naval Research Laboratory, Washington, D. C.)
http://arxiv.org/abs/quant-ph/0101094

Correlations for a new Bell's inequality experiment
Journal-ref: Foundations of Physics Letters, Vol. 15, No. 5, 473 (2002).
Louis Sica (Naval Research Laboratory, Washington, D. C.)
http://arxiv.org/abs/quant-ph/0211031

There are a couple of purported LR models in the bunch. When you've finished reading and critiquing these, and given us your conclusions and recommendations, then I have some more for you to look at. Some of them go back quite a few years, but then Bell's papers were published almost half a century ago.

Of course, nobody was too worried about nature being nonlocal pre Bell, and it seems that nobody's too worried about it post Bell either. After all, there's really no way to know. It's all in how one interprets the logic involved. So, be sure to pay particular attention to the papers that address that.

Anyway, it isn't like these are easy question/considerations.

Well, this statement seems to be a contradiction to the first line in this post: "There have been at least a couple, authored by working physicists, already presented in this thread."

Exactly how do these statements contradict each other? Logic, or rather illogic, of this sort will undoubtedly lead you down the wrong path.

A lot of personal speculations, but still no working LR model. If there is one, please provide the link.

They've been in the thread for quite a while. Why am I not surprised that you didn't read them? They're included in the links above. After you read them, to be fair, I think that we might both agree that calling them LR models is a bit of a stretch. Anyway, whether an LR model of entanglement is possible isn't going to tell us that nature is local any more than a nonlocal model of entanglement tells us that nature is nonlocal. The important question is: how can we infer anything about fundamental reality from the arithmetized Boolean logic constituting Bell, GHZ, and Hardy type theorems? And the point of most of the papers linked to is that we can't. This is actually good news for those who have chosen to believe that nature is nonlocal. It means that they can remain steadfast in their belief, or rather faith, that nature is nonlocal (whatever that might possibly mean). It's also impossible to 'prove' that entanglement correlations are or aren't caused by really fast sub-quantum bike messengers -- though there are some very good reasons not to believe that, just as there are some very good reasons to believe that entanglement correlations can happen via fundamental dynamics constrained by the principle of local action.

They predict the same results that QM does for applicable experiments.

Interesting, could you please describe where the "on/off button" for entangled/not entangled pairs is situated in your LR model? And how does it work?

I don't have an LR model, and don't recall ever saying that I did. However, some professional physicists do. Their models are linked to above.

(If you refer to earlier posts without linking, I take it for granted you have no answer.)

Well, now you have some stuff to look at. Have fun.

 

[DrChinese]

Swindle these:

...

However, some professional physicists do. Their models are linked to above.

That's actually a very poor list, but I will give you this: it's about as good as you could possibly come up with. So you get an A-. I can give you some more names if you like. In fact, Khrennikov had a new paper this week on how 4th order effects cause photons not to be detected.

Most of those are the same authors, and only a few are peer reviewed. The only one I think worth reading is the De Raedt, and that is simply because it is a computer model. If you study it, you will realize how difficult the modeling issue really is. Bell is respected with it - the only one of the lot I believe. Which is to say that their model does not claim to match QM.

 

[DevilsAvocado]

Swindle these:

Why 19 papers? If I were wrong, then one would have been enough!

Exactly how do these statements contradict each other? Logic, or rather illogic, of this sort will undoubtedly lead you down the wrong path.

Well, if you do have 19 papers proving the same (or 19 different) fully functional LR models, the LRM subject could hardly be characterized as: "Anyway, it isn't like these are easy question/considerations."

You, I and anyone else would then completely natural have stated: "Well, it may look like a difficult question, but that fact is that there are 19 papers proving a working LR model, in detail. So the LRM question is already solved, and perfectly clear to the scientific community."

Capice?

They've been in the thread for quite a while. Why am I not surprised that you didn't read them? They're included in the links above.

Why should I read all these 19 papers?

After you read them, to be fair, I think that we might both agree that calling them LR models is a bit of a stretch.

Ahh! Sorry, you’ve already gave me the answer: "calling them LR models is a bit of a stretch"

Conclusion: There is absolutely no reason for me to spend time, looking for a working LR model in your 19 papers – because there is none. Thanks for saving me the time!

I don't have an LR model, and don't recall ever saying that I did. However, some professional physicists do. Their models are linked to above.

I do think you need that break you were mentioning https://www.physicsforums.com/showpost.php?p=2820096&postcount=24", because now you are making contradictory statements in the same post:

calling them LR models is a bit of a stretch

??

Well, now you have some stuff to look at. Have fun.

I don’t want to hurt your feelings – but I’m laughing already!

Take a break. Think it over. Come back as a new man, in possession of that wonderful word "Maybe".

Take care!

 

[billschnieder]

Most of those are the same authors, and only a few are peer reviewed. The only one I think worth reading is the De Raedt, and that is simply because it is a computer model. If you study it, you will realize how difficult the modeling issue really is. Bell is respected with it - the only one of the lot I believe. Which is to say that their model does not claim to match QM.

Huh?

Shuang Zhao · Hans De Raedt · Kristel Michielsen
"Event-by-Event Simulation of Einstein-Podolsky-Rosen-Bohm Experiment"
Found Phys (2008) 38: 322–347
http://arxiv.org/abs/0712.3693

Abstract:
We construct an event-based computer simulation model of the Einstein-Podolsky-Rosen-Bohm experiments with photons. The algorithm is a one-to-one copy of the data gathering and analysis procedures used in real laboratory experiments. We consider two types of experiments, those with a source emitting photons with opposite but otherwise unpredictable polarization and those with a source emitting photons with fixed polarization. In the simulation, the choice of the direction of polarization measurement for each detection event is arbitrary. We use three different procedures to identify pairs of photons and compute the frequency of coincidences by analyzing experimental data and simulation data. The model strictly satisfies Einstein's criteria of local causality, does not rely on any concept of quantum theory and reproduces the results of quantum theory for both types of experiments. We give a rigorous proof that the probabilistic description of the simulation model yields the quantum theoretical expressions for the single- and two-particle expectation values.

H. De Raedt, K. De Raedt, K. Michielsen, K. Keimpema, S. Miyagarbagea
J. Comp. Theor. Nanosci. 4, 957 - 991, (2007)
"Event-by-event simulation of quantum phenomena: Application to Einstein-Podolosky-Rosen-Bohm experiments"
http://arxiv.org/abs/0712.3781

We review the data gathering and analysis procedure used in real Einstein-Podolsky-Rosen-Bohm experiments with photons and we illustrate the procedure by analyzing experimental data. Based on this analysis, we construct event-based computer simulation models in which every essential element in the experiment has a counterpart. The data is analyzed by counting single-particle events and two-particle coincidences, using the same procedure as in experiments. The simulation models strictly satisfy Einstein's criteria of local causality, do not rely on any concept of quantum theory or probability theory, and reproduce all results of quantum theory for a quantum system of two $S=1/2$ particles. We present a rigorous analytical treatment of these models and show that they may yield results that are in exact agreement with quantum theory. The apparent conflict with the folklore on Bell's theorem, stating that such models are not supposed to exist, is resolved. Finally, starting from the principles of probable inference, we derive the probability distributions of quantum theory of the Einstein-Podolsky-Rosen-Bohm experiment without invoking concepts of quantum theory.

K. Michielsen, S. Yuan, S. Zhao, F. Jin, H. De Raedt
"Coexistence of full which-path information and interference in Wheelers delayed choice experiment with photons"
Physica E, Volume 42, Issue 3, January 2010, Pages 348-353
http://arxiv.org/abs/0908.1032

We present a computer simulation model that is a one-to-one copy of an experimental realization of Wheeler's delayed-choice experiment that employs a single photon source and a Mach–Zehnder interferometer composed of a 50/50 input beam splitter and a variable output beam splitter with adjustable reflection coefficient R [V. Jacques, E. Wu, F. Grosshans, F. Treussart, P. Grangier, A. Aspect, J.-F. Roch, Phys. Rev. Lett. 100 (2008) 220402]. For 0<=R<=0.5, experimentally measured values of the interference visibility V and the path distinguishability D, a parameter quantifying the which-path information (WPI), are found to fulfill the complementary relation V2+D2less-than-or-equals, slant1, thereby allowing to obtain partial WPI while keeping interference with limited visibility. The simulation model that is solely based on experimental facts that satisfies Einstein's criterion of local causality and that does not rely on any concept of quantum theory or of probability theory, reproduces quantitatively the averages calculated from quantum theory. Our results prove that it is possible to give a particle-only description of the experiment, that one can have full WPI even if D=0, V=1 and therefore that the relation V^2+D^2<=1 cannot be regarded as quantifying the notion of complementarity.

Extended Boole-Bell inequalities applicable to quantum theory
Authors: Hans De Raedt, Karl Hess, Kristel Michielsen
http://arxiv.org/abs/0901.2546
In conclusion:

We have shown in a series of papers42,43,47,48,59 that it is possible to construct models, that is algorithms, that are locally causal in Einstein’s sense, generate the data set Eq. (126) and reproduce exactly the correlation that is characteristic for a quantum system in the singlet state. These algorithms can be viewed as concrete realizations of Fine’s synchronization model8. According to Bell’s theorem, such models do not exist. This apparent paradox is resolved by the work presented in this paper: There exists no Bell inequality for triples of pairs, there are only EBBI for pairs extracted from triples.
...
The central result of this paper is that the necessary conditions and the proof of the inequalities of Boole for n-tuples of two-valued data (see Section II) can be generalized to real non negative functions of two-valued variables (see Section III) and to quantum theory of two-valued dynamical variables (see Section IV). The resulting inequalities, that we refer to as extended Boole-Bell inequalities (EBBI) for reasons explained in the Introduction and in Section III, have the same form as those of Boole and Bell. Equally central is the fact that
these EBBI express arithmetic relations between numbers that can never be violated by a mathematically correct treatment of the problem: These inequalities derive from the rules of arithmetic and the non negativity of some functions only. A violation of these inequalities is at odds with the commonly
accepted rules of arithmetic or, in the case of quantum theory, with the commonly accepted postulates of quantum theory.
...
A violation of the EBBI cannot be attributed to influences at a distance. The only possible way that a viola-
tion could arise is if grouping is performed in pairs (see Section VII A).

I will just assume that you did not know what you were talking about. And in case you forgot, you still have not addressed a single point of my argument.

 

[DevilsAvocado]

Wooden mechanical horse simulator during WWI.

 

[RUTA]

billschnieder,

I read

Shuang Zhao · Hans De Raedt · Kristel Michielsen
"Event-by-Event Simulation of Einstein-Podolsky-Rosen-Bohm Experiment"
Found Phys (2008) 38: 322–347
http://arxiv.org/abs/0712.3693

I did not spend the hrs it would take me to reproduce all the calculations, so maybe I'm missing something. If so, hopefully you can correct me. Here is what I understand from the paper:

1. Given the manner by which experiments X and Y were carried out and the data analyzed, one cannot rule out local realism (LR).

2. They prove this by constructing an LR simulator which produces data that, when analyzed per the techniques of X and Y, violates Bell's inequality, i.e., gives |S| > 2.

3. They have NOT shown that it is possible to obtain |S| > 2 with an LR model in theory. What they HAVE shown is that it's impossible to rule out an LR model in experiments X and Y which found |S| > 2.

 

[billschnieder]

billschnieder,

I read

Shuang Zhao · Hans De Raedt · Kristel Michielsen
"Event-by-Event Simulation of Einstein-Podolsky-Rosen-Bohm Experiment"
Found Phys (2008) 38: 322–347
http://arxiv.org/abs/0712.3693

I did not spend the hrs it would take me to reproduce all the calculations, so maybe I'm missing something. If so, hopefully you can correct me. Here is what I understand from the paper:

1. Given the manner by which experiments X and Y were carried out and the data analyzed, one cannot rule out local realism (LR).

2. They prove this by constructing an LR simulator which produces data that, when analyzed per the techniques of X and Y, violates Bell's inequality, i.e., gives |S| > 2.

3. They have NOT shown that it is possible to obtain |S| > 2 with an LR model in theory. What they HAVE shown is that it's impossible to rule out an LR model in experiments X and Y which found |S| > 2.

1) and 2) You are correct. In that paper you referred to, they constructed a LR model which violates Bell inequality and agrees with QM.

3) Not quite. In the last I pointed to, they have shown that for purely mathematical reasons, it is not possible to apply Bell-type inequalities to the original EPRB type experiments where only pairs of data are recorded. They have shown by extending the thought experiment such that triples can be measured, and demonstrated that the inequalities are never violated even by QM.

They conclude (page 29):

In the original EPRB though experiment, one can measure pairs of data only, making de-facto impossible to use Boole's inequalities properly. This obstacle is remove in the extended EPRB though experiment discussed in Section VIC. In this extended EPRB experiment, one can measure both pairs and triples and consequantly, it is impossible for the data to violate Boole's inequalities. This statement is generally true: It does not depend on whether the internal dynamics of the apparatuses induces some correlations among different triples or that there are influences at a distance. The fact that this experiment yields triples of two-valued numbers is sufficient to guarantee that Boole's inequalities cannot be violated

The rigorous quantum theoretical treatment of a quantum flux tunneling problem (see Section V) and the EPRB experiment (see Section VI) provide explicit examples that quantum theory can never give rise to violations of the extended boole-bell inequalities

 

[DevilsAvocado]

I did not spend the hrs it would take me to reproduce all the calculations, so maybe I'm missing something.

I think what you may have missed is that Mr. BS is a very big fan of Crackpot Kracklauer:

And he will say and do anything to deceive you there is a real functional LR model. At least ThomasT has the decency to give you a hint ...

calling them LR models is a bit of a stretch

... on what this is all about ...

3. They have NOT shown that it is possible to obtain |S| > 2 with an LR model in theory. What they HAVE shown is that it's impossible to rule out an LR model in experiments X and Y which found |S| > 2.

Absolutely correct. As we all know – this is a computer simulation, nothing more nothing less. And I must say they use very "fancy" words:

Abstract:
We construct an event-based computer simulation model of the Einstein-Podolsky-Rosen-Bohm experiments with photons. The algorithm is a one-to-one copy of the data gathering and analysis procedures used in real laboratory experiments.

I don’t know about the algorithm in the paper, but the algorithm in the actual computer program is NOT "a one-to-one copy of the data gathering and analysis procedures used in real laboratory experiments".

There is actually one little line of code that does all the "magic":

There is absolutely no real "time window", only a pseudo-random number in r0, and this has nothing to do with real experiments – it’s just a case of trial & error and fine-tuning.

Don’t waste your time looking for a real LR model in this computer simulation – you never going to find it.

 

[RUTA]

1) and 2) You are correct. In that paper you referred to, they constructed a LR model which violates Bell inequality and agrees with QM.

3) Not quite. In the last I pointed to, they have shown that for purely mathematical reasons, it is not possible to apply Bell-type inequalities to the original EPRB type experiments where only pairs of data are recorded. They have shown by extending the thought experiment such that triples can be measured, and demonstrated that the inequalities are never violated even by QM.

Let's keep the conversation focused on Found Phys (2008) 38: 322–347. We can discuss the last paper later. Is this correct:

They have NOT shown that it is possible to obtain |S| > 2 with an LR model in theory. What they HAVE shown is that it's impossible to rule out an LR model in experiments X and Y which found |S| > 2.

 

[nismaratwork]

Let's keep the conversation focused on Found Phys (2008) 38: 322–347. We can discuss the last paper later. Is this correct:

They have NOT shown that it is possible to obtain |S| > 2 with an LR model in theory. What they HAVE shown is that it's impossible to rule out an LR model in experiments X and Y which found |S| > 2.

That is a beautiful example of rendering nearly a page of bluster down to a single coherent principle. As a reader of this thread, I thank you.

 

[RUTA]

Don’t waste your time looking for a real LR model in this computer simulation – you never going to find it.

I doubt they have an LR model that yields |S| > 2. If someone had managed to create such a model, it would've sent at very least a ripple though the foundations community and I haven't heard anything about it. I've only read the 2008 FoP paper, so I can only comment on that paper at this time.

In that paper they don't claim to have an LR model that yields |S| > 2. You have to read the paper very carefully so as not to misinterpret their statements. What they DO have is an LR model that generates data which, when subjected to data analysis per a couple of legit EPR-Bell experiments, yields |S| > 2. So, what can you conclude from this? Well, you CANNOT conclude that LR models can violate Bell's inequality. Only that LR models can APPEAR to violate Bell's inequality under certain experimental conditions.

If in fact their calculations are correct (again, I didn't check them, but they were published so I'm willing to give the referees and editor of FoP some credit), I think their work is very good physics and deserved to be published. Their conclusion, while not the "LR savior" anti-EPR advocates are looking for, is not insignificant. I'm going to speculate, hoping someone can correct me if I'm way off (I may be).

The "loop hole" they found has to do with the fact that there is a low coincidence frequency, i.e., the experiment has hundreds of thousands of events but only about 13,000 coincidences. Superficially, of course, that means your LR model need only yield |S| > 2 for the "right" 13,000-element subset of its data. Anyone disagree?

I actually think their work is "cool" and I'm glad someone is doing this dirty "police" work. If I had refereed this paper and found all the calculations to be correct, I would've recommended publication. I think this kind of work is important.

 

[DevilsAvocado]

I doubt they have an LR model that yields |S| > 2. If someone had managed to create such a model, it would've sent at very least a ripple though the foundations community and I haven't heard anything about it. I've only read the 2008 FoP paper, so I can only comment on that paper at this time.

Yeah, and why not a front page in Nature or Scientific American!?

In that paper they don't claim to have an LR model that yields |S| > 2.

This is something Mr. BS must have missed...!? ()

You have to read the paper very carefully so as not to misinterpret their statements. What they DO have is an LR model that generates data which, when subjected to data analysis per a couple of legit EPR-Bell experiments, yields |S| > 2. So, what can you conclude from this? Well, you CANNOT conclude that LR models can violate Bell's inequality. Only that LR models can APPEAR to violate Bell's inequality under certain experimental conditions.

Very interesting! I know DrC is working hard on this, and he made https://www.physicsforums.com/showpost.php?p=2724402&postcount=389" to analyze the data.

The "loop hole" they found has to do with the fact that there is a low coincidence frequency, i.e., the experiment has hundreds of thousands of events but only about 13,000 coincidences. Superficially, of course, that means your LR model need only yield |S| > 2 for the "right" 13,000-element subset of its data. Anyone disagree?

I can’t say for certain, but I know DrC is going to love to discuss this. As far as I understand, they are exploiting the "time window" in a way that the angle is 'responsible' for the amount of random "add-ons". But I can definitely be wrong. We have to wait for DrC.

I actually think their work is "cool" and I'm glad someone is doing this dirty "police" work. If I had refereed this paper and found all the calculations to be correct, I would've recommended publication. I think this kind of work is important.

Yes, it’s cool, but I don’t think it’s cool what Mr. BS is doing – claiming this is proof of a real LR model.

 

[RUTA]

Yes, it’s cool, but I don’t think it’s cool what Mr. BS is doing – claiming this is proof of a real LR model.

It's no proof of an LR model for Bell inequality violations. It's value resides in that it shows why a particular pair of experiments cannot rule out LR models. At least that's what I see.

 

[billschnieder]

They have NOT shown that it is possible to obtain |S| > 2 with an LR model in theory. What they HAVE shown is that it's impossible to rule out an LR model in experiments X and Y which found |S| > 2.

It is clear to me from their paper that
a) They have provided an "LR model" of the experiments under consideration. (Section V)
b) For the two types of experiments they considered, they showed that their model agrees with the QM prediction and violates Bell for some values of d. (Section IV)

Let us assume that we can analyze our simulation model, described in Section V, by
replacing the deterministic sequence of pseudo-random numbers by the mathematical con-
cept of independent random variables, as defined in the (Kolmogorov) theory of probabil-
ity [29, 30]. Under this assumption, each event constitutes a Bernouilli trial [29, 30] and we
can readily obtain analytical expressions for the expectation values that we compute with
the simulation model.
This section serves three purposes. First, it provides a rigorous proof that for up to first
order in W and for d = 4, the probabilistic description of the simulation model exactly
reproduces the single particle averages and the two-particle correlations of quantum theory
for the system under consideration. Second, it illustrates how the presence of the time-
window introduces correlations that cannot be described by the original Bell-like “hidden-
variable” models [14]. Third, it reveals a few hidden assumptions that are implicit in the
derivation of the specific, factorized form of the two-particle correlation that is essential to
Bell’s work.

The authors are not ambiguous about what they claim to have demonstrated. At least to me, it is clear that they have a LR model which violates Bell's inequalities but agrees with QM.

Summarizing: We have demonstrated that a simulation model that strictly satisfies Ein-
stein’s criteria of locality can reproduce, event-by-event, the quantum theoretical results for
EPRB experiments with photons, without using any concept from quantum theory. We
have given a rigorous proof that this model reproduces the single-particle expectations and
the two-particle correlation of two S = 1/2 particles in the singlet state and product state.

If you do not think they have presented an LR model which agrees with QM and disagrees with Bell for the two types of experiments they considered, you will have to clarify what you mean by
1) LR Model
2) obtain |S| > 2 in theory

 

[DevilsAvocado]

OMG, here we go again. Perception and logic at the level of a 10-yearold, now we can "look forward" to >100 posts on this...

 

[JesseM]

It is clear to me from their paper that
a) They have provided an "LR model" of the experiments under consideration. (Section V)
b) For the two types of experiments they considered, they showed that their model agrees with the QM prediction and violates Bell for some values of d. (Section IV)

The two types of experiments they considered are ones that contain experimental loopholes. They do not show in that paper that a LR model could violate Bell inequalities even in a loophole-free experiment that satisfied all the experimental conditions assumed by Bell. Note on p. 4 where they say:

The crucial
point of the present and of our earlier work [15, 21, 22, 23] is that we simulate a model of
the real EPRB experiments, not of the simplified, gedanken-type version that is commonly
used [17, 18, 19].

Also note that DrChinese did a detailed analysis of the De Raedt model on this thread, and concluded in post #47:

I have been working with the De Raedt team for several months to address the issue identified in this thread. Thanks especially to Dr. Kristel Michielsen for substantial time and effort to work with me on this.

The issue I identified was rectified very quickly using what they call their "Model 2" algorithm. My earlier analysis was using their older "Model 1" algorithm. After getting to the point where we were able to compare statistics for a jointly agreed upon group of settings, I am satisfied that they have a simulation which accomplishes - in essence - what they claim.

...

Please keep in mind that the De Raedt model is a computer simulation which exploits the coincidence time window as a means to achieve a very interesting result: It is local realistic. Therefore, it is able to provide event by event detail for 3 (or more) suimultaneous settings (i.e. it is realistic). It does this with an algorithm which is fully independent (i.e. local/separable). It does not violate a Bell Inequality for the full universe but does (somewhat) for the sample.

So, seems to be exploiting some variant of the detector efficiency loophole.

 

[billschnieder]

The two types of experiments they considered are ones that contain experimental loopholes. They do not show in that paper that a LR model could violate Bell inequalities even in a loophole-free experiment that satisfied all the experimental conditions assumed by Bell.

I take it you believe it is possible to perform an EPRB experiment which is 100% faithful to all of Bell's assumptions. For reasons I have already explained, I do not share that belief. The fact that no such experiment has ever been performed is definitely telling.

And since non-localists rely on the same "loopholed experiments" to proclaim the demise of locality, a locally causal explanation of those same experiments however "loopholed" they are, is an effective counter argument. So contrary to what you might think, the fact that the experiments so modeled, are not loophole free, is not a serious response to the model.

So, seems to be exploiting some variant of the detector efficiency loophole.

No. Read the paper! I should also say I simply enjoy your choice of words here: "exploiting .. loophole". When
Weihs et al. did their experiments and published the result, I did not hear non-localists clamouring that they "exploited ... loophole".

Also note that DrChinese did a detailed analysis of the De Raedt model on this thread, and concluded in post #47:

You mean the same DrChinese who said contrary to what the authors themselves explicitly claimed in the paper that:

The only one I think worth reading is the De Raedt,... Bell is respected with it - the only one of the lot I believe. Which is to say that their model does not claim to match QM.

 

[JesseM]

I take it you believe it is possible to perform an EPRB experiment which is 100% faithful to all of Bell's assumptions.

It would be possible (in principle) to perform an experiment 100% faithful to all his assumptions about the observable conditions of the experiment, yes. Of course the experiment need not match the theoretical assumptions about hidden variables, since the whole point would be to compare a real experiment which matches these observable experimental conditions to what LR hidden-variables theories would predict about an experiment which matches these observable experimental conditions.

And since theorists have come up with modified Bell inequalities that deal with imperfect detector efficiency, it's really only necessary to perform an experiment where the detector efficiency is above a certain threshold, it doesn't have to be perfect as assumed in the original Bell inequalities. As we've discussed before, there have been experiments that got the detector efficiency above such a threshold, although they didn't simultaneously close the locality loophole (and we've also discussed why I think it's very unlikely the true laws of physics would be a hidden-variable theory that exploits both loopholes simultaneously, and why I think it's likely that experiments closing both loopholes will be possible in the near future).

And since non-localists rely on the same "loopholed experiments" to proclaim the demise of locality, a locally causal explanation of those same experiments however "loopholed" they are, is an effective counter argument.

Not if the De Raedt model fails to simultaneously exploit the locality loophole (or it does but requires a very contrived and complicated algorithm).

So, seems to be exploiting some variant of the detector efficiency loophole.

No. Read the paper!

I'm trusting DrChinese's analysis, unless you can show where it's wrong--do you claim there is some section of the paper that demonstrates that every simulated photon emitted by the source is actually detected? If so, perhaps you could quote that section?

You mean the same DrChinese who said contrary to what the authors themselves explicitly claimed in the paper that:

The only one I think worth reading is the De Raedt,... Bell is respected with it - the only one of the lot I believe. Which is to say that their model does not claim to match QM.

Where do the authors "explicitly claim" otherwise? Keep in mind the context, DrChinese would presumably say here that a model which violates the Bell inequalities in experiments with loopholes but respects them in loophole-free experiments is still a model where "Bell is respected". So the fact that the authors may talk about how Bell inequalities are violated doesn't mean that they would disagree that "Bell is respected" in the sense which DrChinese meant that phrase.