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Bell's theorem - for or against Hidden Variables?
Of course I know him, I have already had some longer discussions with him in his forum. (Ok, it is not his, but of one of his supporters.) The article you have linked is weak:

Quote:There is no competing theory that banishes the weirdness and embraces a reality that exists independent of our observations of it. The spookiness, it seems, is here to stay.

You see, it already starts with a lie. There are realistic theories equivalent to quantum theory, and I have only started here with dBB, because it is the oldest and most well-known. There are others, and imho better, like Nelsonian stochastics and Caticha's entropic dynamics. If I find time I will present them here too.

Quote:He claims that physicists' supposed proofs of the impossibility of more "realistic" theories rest on false assumptions and so don't prove much at all.
There is no "supposed proof of the impossibility of more 'realistic' theories". What Christian questions is Bell's theorem, which rejects only the possibility of Einstein-causal realistic theories.

Quote:"Contrary to the received wisdom," he says, "quantum theory doesn't rule out the possibility of a deeper theory, even one that might be fully deterministic."
"Received wisdom" has accepted Bohm's proof of existence, by construction, of a hidden variable theory which is fully deterministic.
Quote:Christian's conclusion follows from a relatively simple calculation using alternative mathematics, described in a paper now under review at the journal
Physical Review Letters.
There is no such animal as "alternative mathematics" (or is this the type of mathematics where 2+2=5?). And, of course, PRL has rejected this.

Quote:Bell imagined an experiment that would send particles from millions of entangled pairs to distant places around the globe, where experimenters would measure their spins. He assumed that some "real", pre-existing properties of the two particles would determine the measurement outcomes. He also assumed that relativity remains intact, so if measurements of entangled particles were made at the same moment, the properties of one particle could not possibly affect its entangled twin quickly enough. From these assumptions, Bell predicted what such experimenters would find.

What I have emphasized is wrong too - Bell has not assumed this, but derived this using the classical EPR argument. And the relativity about relativity was necessary only to prove this. But this error is already forgivable, there are too many scientists who have made the same error interpreting Bell too. (Read the Norsen paper about this, he is one of the guys who does not make this error.)

Quote:Recent experiments have gone further and tried to establish which of the two ideas has to go: locality or realism. They concluded that we have to abandon the
idea of an objective reality (New Scientist, 23 June, p 30).
More nonsense. I don't have access to this, but I would guess that this is about some small and irrelevant class of realistic theories which violates Einstein causality, but is restricted by some other conditions in such a way that one can derive also some inequality similar to Bell's, which is violated by quantum theory (and all its completely realistic interpretations like dBB) too.

Quote:Bell assumed the hidden variables in his argument would be familiar numbers, akin to the value of a velocity or a mass. Such numbers obey the ordinary rules of algebra, including a law that says that the order of multiplication doesn't matter - so that, for example, 2 × 5 equals 5 × 2. This property of multiplication is called commutation. The idea that hidden variables are commuting numbers might seem so basic as to be beyond question, but Christian argues it is important to question this point because mathematicians know that different kinds of variables needn't obey commutative algebra.
A complete misrepresentation. Bell makes no assumption at all about the hidden variables. Except that they are elements \(\lambda\) of some set of possible values of these hidden variables, \(\lambda\in\Lambda\). All what Bell assumes is that these hidden variables, together with the parameters of the measurement device a, define the result of the measurement A, which is spin up or down, or +1 resp. -1, so that \(A=A(\lambda,a)\in\{-1,+1\}\).

Quote:The debate seems likely to continue for some time while researchers puzzle over details.

No. There is no need to puzzle over details, there is also no debate - there is full agreement in the scientific community that Christian is wrong.

In the remaining part about others I have not seen obvious errors. So it may be he was simply misguided by Christian.

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RE: Bell's theorem - for or against Hidden Variables? - by Schmelzer - 05-21-2016, 05:59 PM

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