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Why the De Raedt Local Realistic Computer Simulations are wrong 
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#55
May111, 05:11 PM

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DrChinese, I'm also interested in the same paper (mentioned in the message just before this) that alleged that Bell's Theorem was wrong and really supported Local Realism. Were you able to find a flaw after 4 months of analyzing it? If you can't find a flaw, then Bell's Theorem is refuted and local realism holds? This is important as proof of the paper claims can refute even Aspect experiment, etc. and entertain the possibility of local hidden variables and let us return back to the days of Einstein EPR.



#56
May211, 08:52 AM

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#57
Jun1611, 06:29 AM

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http://physicsforums.com/showthread.php?t=499002 


#58
Jun1611, 06:41 PM

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May I just add that there’s one variable missing to get this kind of realism working; Varon also need to update his gear and get an authentic phonograph. I guess any local dealer could help him out, they often keep this stuff in the basement, hidden under 9″ of dust. ... or one could just make it easy and watch The Return of the Living Dead – it will have the same effect ... 


#61
Apr2612, 01:58 PM

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#62
Apr2612, 02:17 PM

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So my apologies. I will use the term "coincidence time window" instead of detector efficiency, with the understanding that in a computer simulation, some of this is arbitrary. If it were to be considered a candidate model, you would want to challenge whether such an effect really existed. Specifically, how does the photon get delayed without losing its entangled characteristic (i.e. perfect correlations)? Because if it lost that, it should NOT be considered at all. If you vary the k= setting (in the spreadsheet, tab B. Entangled) from 1 to 30 to 100 you will see how things change in a very unphysical manner. 


#63
Apr2712, 12:41 PM

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#64
Apr2712, 02:14 PM

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#65
Apr2712, 03:28 PM

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By the way, this thread is dredged up from some time ago. I would like to say that the de Raedt team was kind enough to work with me to refine my spreadsheet model. After they supplied me with some modifications to their original Fortran code, my primary objection* to their model disappeared. I have not come to understand why it was able to accomplish that feat  simply because I have not devoted the time to the matter.
So while I disagree with Hans and Kristel on the conclusions that should be drawn from the model, I agree with its operation. Here is the link to the Excel spreadsheet model: http://drchinese.com/David/DeRaedtCo...hPhotons.C.xls * Which had to do with a specific case of PDC simulation, not the general case. 


#66
Apr2712, 04:22 PM

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If you could be kind as to explain why you disagree with their conclusion, despite agreeing that their model is local and realistic, then we can discuss that. 


#67
Apr2712, 05:10 PM

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The good:  It is 100% local and realistic, so no issue there.  It does violate a Bell Inequality, so it succeeds there.  It did model product state statistics correctly when it needed to, which was my original objection to the simulation itself. The bad:  It posits physical effects that are new, and subject to experimental rejection or confirmation (don't hold your breath on that one).  It only matches experiment when the window size is very small, otherwise it deviates quite quickly towards the Bell boundary.  It beats the Bell Inequality when the window size is made to be medium, but only barely.  And most telling, it does not match QM for the full universe. Now, you don't seem to think this is a problem but it really is quite serious for a model of this type. Because there would be tests that could be constructed to exploit this difference. This is part of the reason that the team has attempted to construct further simulations to take things a few steps farther.  It does not match the dynamics of actual data when the time window is varied. I.e. it is obviously ad hoc. DrC 


#68
Apr2712, 08:56 PM

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#69
Apr3012, 09:05 AM

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2.Not so! Otherwise it wouldn't be an issue. 


#70
Apr3012, 10:53 AM

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2) This is false. Look at figure 2 in their article in which they analyze the actual experimental data, varying the window: http://arxiv.org/pdf/1112.2629v1.pdf. QM is violated by 5 standard deviations! 


#71
May212, 09:31 AM

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#72
May212, 10:44 AM

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