harrylin
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Ah yes, in fact you did make it clear, thanks - I just hadn't looked at that part, as it appeared to refer to the line before.Delta Kilo said:I thought I made it clear [..]
Ah yes, in fact you did make it clear, thanks - I just hadn't looked at that part, as it appeared to refer to the line before.Delta Kilo said:I thought I made it clear [..]
Delta Kilo said:Is it really?
Consider [itex]\int_0^1 \operatorname{sign}(y-x) dx[/itex], where [itex]0 \le y \le 1[/itex]
billschnieder said:I've tried this several times and I do not get your results. I get every time:
[itex]\int_0^1 \operatorname{sign}(y-x) dx = sign(y-1)[/itex]
Delta Kilo said:I thought I made it clear:EDIT: Oops, just realized I had the sign wrong in the above (I had [itex]1-2y[/itex] instead of [itex]2y-1[/itex]), but they cancel each other out so the end result is the same anyway.

ThomasT said:Since there seems to be some confusion about the meaning of the thread title, I have a question ... for anybody.
Q1: Can the QM prediction (for either the Stern-Gerlach setup that Bell dealt with, or an optical Bell test setup) be reproduced by the form in Bell's equation 2 in his 1964 paper?
That that can't be done has, afaik, been definitively demonstrated and is one way of stating Bell's theorem (without any inference regarding nonlocality), and rules out Bell-type LR models of quantum entanglement.
Q2: So I'm wondering if that's what the classical challenge to Bell's Theorem is eventually going to be getting at.
Q3: If not, then what, exactly, is the classical challenge to Bell's theorem that the title refers to?
ThomasT said:Since there seems to be some confusion about the meaning of the thread title, I have a question ... for anybody.
Q1: Can the QM prediction (for either the Stern-Gerlach setup that Bell dealt with, or an optical Bell test setup) be reproduced by the form in Bell's equation 2 in his 1964 paper?
That that can't be done has, afaik, been definitively demonstrated and is one way of stating Bell's theorem (without any inference regarding nonlocality), and rules out Bell-type LR models of quantum entanglement.
Q2: So I'm wondering if that's what the classical challenge to Bell's Theorem is eventually going to be getting at.
Q3: If not, then what, exactly, is the classical challenge to Bell's theorem that the title refers to?
billschnieder said:I should apologize to Delta Kilo for prematurely judging his integral when in fact he was correct and I was wrong.
I guess it is up to Gordon now to say what next, as it appears his challenge has been solved. One other thing to note is that even the sign function has three values (-1,0,+1).
ThomasT said:Can the QM prediction (for either the Stern-Gerlach setup that Bell dealt with, or an optical Bell test setup) be reproduced by the form in Bell's equation 2 in his 1964 paper?
...
I found it easier to follow after I recast it in the following form; just makes it easier to follow without too much effort.
[itex]E(AB)_V = \int dx \, \rho (x)AB[/itex]
[itex]= \int dx \, \rho (x) \left [<br /> P({A^+}{B^+}|V) <br /> - P({A^+}{B^-}|V) <br /> - P({A^-}{B^+}|V) <br /> + P({A^-}{B^-}|V)<br /> \right ][/itex]
[itex]= \int dx \, \rho (x) \left [<br /> P(A^+|V)P(B^+|V,\,A^+) <br /> - P(A^+|V)P(B^-|V,\,A^+)<br /> - P(A^-|V)P(B^+|V,\,A^-)<br /> + P(A^-|V)P(B^+|V,\,A^-)<br /> \right ][/itex]
[itex]= \int dx \, \rho (x) \left [ <br /> P(A^+|V)\left [P(B^+|V,\,A^+) - P(B^-|V,\,A^+) \right ] <br /> - P(A^-|V)\left [P(B^+|V,\,A^-) - P(B^-|V,\,A^-) \right ]<br /> \right ][/itex]
[itex]= \int dx \, \rho (x) \frac{1}{2}\left [ <br /> P(B^+|V,\,A^+) - P(B^-|V,\,A^+) - P(B^+|V,\,A^-) + P(B^-|V,\,A^-) \right ][/itex]
since for random variables
[itex]P(A^+|V) = P(A^-|V) = \frac{1}{2}[/itex]
Gordon Watson said:Continuing:
6. Designating the general conditions of the classical ("Bell-style") tests on the correlated particles in the OP by W, we are interested in the general application of Bell's (1964) protocol [from (V-1) - (V-5)] thus:
(W-1) E(AB)W = ∫dx ρ(x) AB =
(W-2) ∫dx ρ(x) [P(B+|W, A+) - P(B-|W, A+) - P(B+|W, A-) + P(B-|W, A-)]/2 =
(W-3) ∫dx ρ(x) [(cos2(a, b)+ 2) - (- cos2(a, b)+ 2) - (- cos2(a, b)+ 2) + (cos2(a, b)+ 2)]/8 = (1/2) cos2(a, b):
QED; we have derived the correct answer for classical experiment W (from the OP): using classical principles (including the classical Malus Law), and in agreement with Bell that ∫dx ρ(x) = 1.
To be continued: but please report any errors or confusions, etc., in the interim.
..
Gordon Watson said:Re the correlations: Since the HVs are generally unknown random variables, it figures that correlations must arise from other sources (since "random" is hardly the sort of correlation we are looking for). But the A and B outcomes (from particle-device interactions), knock the HVs into shape (as it were), and so the HVs may be eliminated from the correlation functions (as we see). Thus the correlations, deriving from the distribution of the outcomes, are independent of the HVs.
DrChinese said:...and thus leaving the (future) relative angle settings of the observation devices as the only relevant quantities in the outcomes. We live in an observer dependent universe.
billschnieder said:I can verify that this is correct as follows:
[itex] P(B^+|W,\,{A^+}) + P(B^-|W,\,{A^+}) = 1, \; \;<br /> P(B^+|W,\,{A^-}) + P(B^-|W,\,{A^-}) = 1[/itex]
[itex]P(B^+|W,\,{A^+}) = P(_B^-|W,\,{A^-}) = \frac{1}{2}cos^2(a-b) + \frac{1}{4}[/itex]
therefore
[itex]P(B^-|W,\,{A^+}) = P(B^+|W,\,{A^-}) = -\frac{1}{2}cos^2(a-b) + \frac{3}{4}[/itex]
from V-4:
[itex]E(AB)_w <br /> = \int dx \, \rho (x) \frac{1}{2}\left [ <br /> P(B^+|W,\,{A^+}) - P(B^-|W,\,{A^+}) - P(B^+|W,\,{A^-}) + P(B^-|W,\,{A^-}) \right ][/itex]
[itex]= \int dx \, \rho (x) \frac{1}{8}\left [ <br /> \left [2cos^2(a-b) + 1 \right ] <br /> - \left [-2cos^2(a-b) + 3 \right ]<br /> - \left [-2cos^2(a-b) + 3 \right ]<br /> +\left [2cos^2(a-b) + 1 \right ] <br /> \right ][/itex]
[itex]= \int dx \, \rho (x)\left [ <br /> cos^2(a-b) - \frac{1}{2}<br /> \right ] = cos^2(a-b) - \frac{1}{2} = \frac{1}{2}cos(2\theta), \;\;\; for \; \theta = a - b[/itex]
Gordon Watson said:Many thanks, Bill, much appreciated: with a small point for the future.
Note that a and b are detector orientations: often defined as unit-vectors in a 2-space orthogonal to the line-of-flight; or in 3-space.
The latter is important in considering the spherically-symmetric singlet-state.
So, in Bell-studies, the most general way to represent the angle between these vectors (in the argument of a trig-function) is (a, b).
Gordon Watson said:Aspect (2004) -- http://arxiv.org/abs/quant-ph/0402001 -- represents an optical Bell setup. Designating its general conditions by Y, and applying Bell's protocol as part of the form that you request, we proceed from (V-4) above as follows:
(Y-1) E(AB)Aspect (2004) = E(AB)Y =
(Y-2) ∫dx ρ(x) [P(B+|Y, A+) - P(B-|Y, A+) - P(B+|Y, A-) + P(B-|Y, A-)]/2 =
(Y-3) ∫dx ρ(x) [cos2(a, b) - sin2(a, b) - sin2(a, b) + cos2(a, b)]/2 = cos2(a, b):
which is the correct result for Aspect (2004); see his equation (6).
Gordon Watson said:..
DrC, I would welcome and appreciate your expanding on the point that you seek to make. It is not at all clear to me. Thanks. GW
billschnieder said:It appears you have classically reproduced the QM result E(AB) for the Aspect experiment. However, I'm not sure how you obtained [itex]P(B^+|Y, A^+) = \cos^2(a,b)[/itex]
billschnieder said:Thanks to Delta Kilo, we do have a locally causal derivation of the W case. Do you have a derivation of the Aspect case that is locally causal? Is it a straightforward application of Malus?
billschnieder said:In other words, why is [itex]P(B^+|Y, A^+) = \cos^2(a,b)[/itex] for Aspect 2004 (Y), different from [itex]P(B^+|W, A^+) = \frac{1}{2}cos^2(a,b) + \frac{1}{4}[/itex] for the the classical case in the OP (W)?
billschnieder said:Also since
[itex]P(B^+|W,\,{A^+}) + P(B^-|W,\,{A^+}) = 1, \; \; <br /> P(B^+|W,\,{A^-}) + P(B^-|W,\,{A^-}) = 1[/itex]
and [itex]P(B^+|W,\,{A^+}) = P(B^-|W,\,{A^-})[/itex]
Your condition V-4 can be reduced to:
[itex]E(AB)_V= \int dx \, \rho (x) \left [ 2 \cdot P(B^+|V,\,A^+) - 1 \right ][/itex]
DrChinese said:We live in an observer dependent universe. All of the major interpretations of QM agree on this point in some fashion: Copenhagen, MWI, dBB/BM, TS (Time Symmetric).
Given the recent PBR theorem (see 2 of many links below), isn’t non-locality implied by any “realistic” model by PBR theorem itself, irrespective of Bell’s. For instance Leifer writes:billschnieder said:Gordon has now shown that he can obtain classically the result that agrees with QM for the Aspect experiment in a local-realistic manner, which implies a violation of Bell's inequalities and a refutation of Bell's theorem.
The quantum state cannot be interpreted statisticallyIt (PBR) provides a simple proof of many other known theorems, and it supercharges the EPR argument, converting it into a rigorous proof of nonlocality that has the same status as Bell’s theorem...Nevertheless, the PBR result now gives an arguably simpler route to the same conclusion by ruling out psi-epistemic theories, allowing us to infer nonlocality directly from EPR.
billschnieder said:DrC et al,
Gordon has now shown that he can obtain classically the result that agrees with QM for the Aspect experiment in a local-realistic manner, which implies a violation of Bell's inequalities and a refutation of Bell's theorem. I'm surprised this is all you have to say in return. Besides, it is not clear to me how what you say above is relevant to the issue here especially since you already agreed earlier that the OP experiment was entirely classical and local realistic and yet E(AB) contains only the angular settings. Thus, the fact that E(AB) for any experiment contains only the angular settings means squat as far as locality or realism is concerned, no?
Sure, we agree about that. I'm referring to his reproduction of the QM expectation value in post #102. Maybe you missed it. Check it out.DrChinese said:It is really impossible at this point to comment, other that to repeat what has already been stated: his classical thought experiment yields classical probabilities (I gave those) that don't violate a Bell Inequality.
That is strange given that all I'm asking is for someone else to verify the math in post #102 to make sure it is correct because I did not find any errors in it, and it appeared to reproduce the QM expectation classically. So check and explain why you think it is wrong *if* you think it is wrong.Your pushing the idea that Gordon has disproved Bell here is particularly sad.
If the thread is no longer useful for you, feel free to not read it anymore. Clearly there are issues remaining to be clarified for those still participating. I assumed that if you believe Bell's theorem, you would be alarmed anytime the QM expectation values for the EPRB are reproduced in a local-realistic manner, and would seize the opportunity to point out where the error is if there was an error at all! But instead, you start dropping hints/suggestions that the thread should be closed. I wonder why ...Unless there is a new question or example put forth, I personally think this thread has reached the end of its useful life.
DrChinese said:I consider your comments either born of insincerity or ignorance or perhaps a strange form of humor, really cannot figure out what you are trying to do here.
right back at ya!DrChinese said:It is really impossible at this point to comment, other that to repeat what has already been stated: his classical thought experiment yields classical probabilities (I gave those) that don't violate a Bell Inequality. Unless there is something serious offered forward, I do not plan to comment further on the example itself as I have indicated.
In cases where a Bell Inequality does not matter (as in a classical example), the observer angular settings would not imply failure of realism (observer independence).
Your pushing the idea that Gordon has disproved Bell here is particularly sad. I consider your comments either born of insincerity or ignorance or perhaps a strange form of humor, really cannot figure out what you are trying to do here.
Unless there is a new question or example put forth, I personally think this thread has reached the end of its useful life.
billschnieder said:Sure, we agree about that. I'm referring to his reproduction of the QM expectation value in post #102. Maybe you missed it. Check it out.That is strange given that all I'm asking is for someone else to verify the math in post #102 to make sure it is correct because I did not find any errors in it, and it appeared to reproduce the QM expectation classically. So check and explain why you think it is wrong *if* you think it is wrong.If the thread is no longer useful for you, feel free to not read it anymore. Clearly there are issues remaining to be clarified for those still participating. I assumed that if you believe Bell's theorem, you would be alarmed anytime the QM expectation values for the EPRB are reproduced in a local-realistic manner, and would seize the opportunity to point out where the error is if there was an error at all! But instead, you start dropping hints/suggestions that the thread should be closed. I wonder why ...
right back at ya!
Gordon Watson said:DrC, I am hoping that thes question might bring you back to this thread, for it is not yet clear (to me) the critical point that you are making:
DrChinese said:Gordon, it is not appropriate to take a classical example, run a few formulas and say "Voila! Bell is wrong." I have already provided the math to show you your example is classical and does not violate Bell. I believe zonde and Mark M both showed the same thing. Sadly, billschnieder is using you in some strange way and is egging you on. I do not know his reason, but again I implore you to go back to ground zero in learning about the math of Bell.
The idea of this thread - see title - is absurd. You have never done anything so far to show otherwise despite the time I have taken to assist you. Which is why I don't think further discussion here is warranted.
And I respect de Raedt and Michielsen too much to recommend you send your classical example to them so they can analyze your ground-breaking work. So perhaps you might send it to Joy Christian instead.![]()