
#163
Dec2512, 02:16 PM

P: 50

Hmm how does Bohmian mechanics deal with KochenSpecker?




#164
Dec2512, 02:36 PM

PF Gold
P: 670





#165
Dec2512, 02:55 PM

P: 50

Aah right coming back to me, nonlocality allows plausible contextuality.




#166
Dec2512, 05:15 PM

P: 53

In a photon experiment with spacelike separation, I have shown that unless the optical pathways are blocked for a very significant portion of presumed particle flight, then a speedoflight interaction acting for a nonzero time interval can explain the correlations. A traditional way to look at it would be to consider an extended wave packet with more information than just a frequency, duration, and envelope. Synchronized rapidly rotating disks, with a slit in each, like the "chopper" described in Hans De Raedt's paper on Neutron interferometry, (http://arxiv.org/abs/1208.2367) but placed as close to the measuring aparatus as possible. The size of the slit should be as small as possible without reaching the scale where a significant portion of photons interact with the slit but still reach the detector. In this experiment, the coincident detection counts diminish but their correlation should not. There may be an equivalent experimental condition, which is why I'm curious as to what measures are being taken with future experiments. If it is just closing all of the recognized loopholes in one experiment, then I believe that would not be definitive. Another compelling theoretical case for doing an experiment with the "chopper" condition is John Cramer's transactional interpretation of QM (http://www.npl.washington.edu/npl/in...qm/TI_toc.html). The experiment then might at least tell us where the superluminal effects go: E>A and E>B or A<>B Of course, this would only lead to a conclusive result if the mechanism of "teleportation" travels only through the same pathways as the particles themselves. 



#167
Dec2512, 05:23 PM

PF Gold
P: 670

http://plato.stanford.edu/entries/ko...ker/index.html So, while the KS theorem establishes a contradiction between VD + NC and QM, the qualification above immunizes Bohmian mechanics from contradiction. 



#168
Dec2512, 08:31 PM

P: 53

repost to follow because of edit issue ...




#169
Dec2512, 08:35 PM

P: 53

Regarding Bell and KS, I'm trying to get clarity on the definitions in order to determine applicability to a hypothetical system. Consider a system of two vectors, A and B, at two points in space X_{1},X_{2}, with c=1. Let the two be in a bidirecitonal relationship that maintains the rule A(t)[itex]\bullet[/itex]B(tX_{1}X_{2})=1 and B(t)[itex]\bullet[/itex]A(tX_{1}X_{2})=1.
This system seems to me to be both realistic and deterministic? It seems to me to be value definite too, in that the result of an observation is the negative of the observed? It seems to be contextual, in that an observer affects the observed. Although, an observer in a directed relationship could observe noncontextually. But, there is the question of what is being observed. Is it the observed in the past, or is it the "messenger"? There are solutions to the equation involving a chain of vectors, so there's the question of "which" is being observed too! 



#170
Dec2612, 06:47 AM

P: 60

mbd asked "What are the additional experimental conditions in the upcoming potentially definitive experiments?"
It's not a question of "additional". Bell's papers make perfectly clear how a BellCHSH experiment needs to be performed, in order that the experimental findings would disprove local realism. Alice's measurement setting needs to be generated at Alice's location while the particles are "in flight" and her measurement needs to be completed before any information concerning Bob's setting could have reached her apparatus; and vice versa. Implicit in this is that every pair of particles do both get measured. In real world experiments to date, though the spacetime constraints have been satisfied, it has not been possible to detect and measure every particle. The outcome at each measurement station is not +/1 but +/1 or "no show". For a situation with ternary outcomes one needs a different, appropriate, Bell inequality. If one focusses on the correlations between outcomes conditional on both particles being measured, the appropriate inequality looks just like CHSH but with the bound "2" replaced by 2 plus a positive term depending on the overall experimental efficiency, defined as the minimum over settings and parties of the probability of an outcome in one party's wing of the experiment given an outcome in the other. When the efficiency is above 70% then the relevant bound is smaller than 2 sqrt 2. So a good experiment has to have efficiency above 70% and close to perfect reproduction of the singlet correlations. And detectors far apart, setting generation fast and unpredictable, duration of measurement fast. It has still not been done, though I believe several experimental groups are getting close, at last, 30 years on from Aspect's experiment. 



#171
Dec2612, 07:04 AM

P: 50

I'm still having no joy trying to understand Joy Christian's rebuttal. If A(a,\lambda) = +1 when \lambda = +1 and A(a,\lambda) = 1 when \lambda = 1, in what sense doesn't A(a,\lambda) = \lambda? or is the +/1 that A(a\lambda) is set to something other than normal +/1 which don't multiply together as we expect? Surely someone with his credentials hasn't completely lost the plot?




#172
Dec2612, 08:15 AM

P: 60

"Surely someone with his credentials hasn't completely lost the plot?"
What credentials? A PhD in the foundations of physics means you are good with words and ideas and imagery, and are wellread. It doesn't mean that you can do mathematics. In earlier versions of Christian's model, the sign error was much more deeply hidden. Florin Moldoveanu carefully studied all versions and found the same error in about four different guises. 



#173
Dec2612, 08:51 AM

P: 50

I think there is a whole range of unrecognized "cognitive disorders" out there that aren't being diagnosed or treated by psychologists.
The other day I found a paper by someone who thought that they had proven that the standard definition of natural numbers implied the existence of a greatest natural number if the natural numbers are not treated as a proper class. The author was clearly intelligent, had a PhD, but was completely failing to grasp the very basics of the theory of ordinals  and was unaware that he was failing to grasp it. Worse, there was the case of a fairly capable student, who picked up the basics of Pascal programming within a day ... and went on to write a program which in his words was for testing if infinity existed ...by writing an unending loop that incremented a counter and printed the result. oO 



#174
Dec2612, 10:24 AM

Sci Advisor
PF Gold
P: 5,146

Here is a new paper with another take:
http://arxiv.org/abs/1212.4854 Abstract: "I present a local, deterministic model of the EPRBohm experiment, inspired by recent work by Joy Christian, that appears at first blush to be in tension with Belltype theorems. I argue that the model ultimately fails to do what a hidden variable theory needs to do, but that it is interesting nonetheless because the way it fails helps clarify the scope and generality of Belltype theorems. I formulate and prove a minor proposition that makes explicit how Belltype theorems rule out models of the sort I describe here. " (Of course Christian disagrees...) 



#175
Dec2612, 11:43 AM

P: 53

In C#, though, both negative infinity and positive infinity exist: Double.PositiveInfinity and Double.NegativeInfinity. 



#176
Dec2612, 12:39 PM

P: 60

Why should probability not ontologically exist? What kind of prejudice is that? I think quantum mechanics is telling us that it does exist, despite our intuition or instinct to the contrary. Our brains evolved and led us from success to success by hardwiring in us a belief that nothing happens without a cause... this belief worked just fine, till we ran up against quantum mechanics.




#177
Dec2612, 12:42 PM

P: 50

Its even got infinitisimals (in a sense) Double.Epsilon :)




#178
Dec2612, 12:47 PM

P: 50

Theory of Hidden Authors ... just a thought, is it possible that Joy Christian really doesn't know much math at all and all the math is being ghost written for him by someone else who is trying to rigorize some hand waving from Christian and stuff is getting lost in translation somewhere?




#179
Dec2612, 12:58 PM

Sci Advisor
Thanks
P: 2,951





#180
Dec2612, 01:08 PM

P: 53




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