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Sunday, April 20, 2014

Agree that Mermin is rehashing Bohr

I previously commented on a Nature article:
My only quarrel with Mermin is that he acts as if he is saying something new. He is just reciting the view of Bohr and everyone else not infected with Einstein's disease.
Before that, I said:
I am not sure why a new name is needed to reiterate what Bohr said. After all, Bohr won those Bohr-Einstein debates back in the 1930s.
Lubos Motl now says the same thing:
The particular buzzword "Quantum Bayesianism" (or "Qbism") is meant to describe this 2001 preprint (and 2002 PRA paper) by Carlton M. Caves, Christopher A. Fuchs, Ruediger Schack. It describes probabilities in quantum mechanics in the way they are. Your humble correspondent would probably agree with all papers in literature presenting Qbism. I just have a trouble with the "credits", with the claim that "Quantum Bayesianism" is some really new 21st contribution to physics (and also with the prominent role that is given to Thomas Bayes). It is really just a new brand that describes the very same thing that the Copenhagen school understood well. They just didn't expect that the meaning of probabilities in quantum mechanics – which is really simple and obvious for anyone who is not prejudiced – would remain a source of controversy among professional physicists for at least 90 years so they didn't write long essays and they weren't inventing new words to describe the same thing.
He also mocks Mermin's discussion of the problem of Now, just as I also did. So I actually agree with him about something.

Apparently Mermin and Lumo have to keep repeating 80yo explanations of quantum mechanics because so many get it wrong. Here is the latest example:
"Even great physicists will tell you that nobody understands quantum mechanics, although we use it every day," said Stanford philosophy Professor Thomas Ryckman. ...

One of them, the philosopher maintains, is Albert Einstein's unorthodox critique that quantum theory was incomplete and that a larger mathematical description of reality was possible. "Because his views went against the prevailing wisdom of his time, most physicists took Einstein's hostility to quantum mechanics to be a sign of senility," Ryckman said. ...

"Because he was arguing against a very empirically successful theory," said Ryckman, "his scientific biographer Abraham Pais asserted that after 1925, 'Einstein might as well have gone fishing.'" ...

As it turns out, in the 1960s, a physicist visiting Stanford named John S. Bell wrote a paper reviving Einstein's critique of quantum mechanics, arguing that if the late scientist were right, the quantum formalism would be describing a reality greatly at odds with our everyday experience of familiar objects. "By the 1980s it was possible to do an actual experiment to test this," Ryckman said, "and in fact it was shown that the world of quantum particles is indeed 'entangled.'"
In other words, those experiments showed that the 1930 understanding of quantum mechanics was correct, and that Einstein and Bell were barking up the wrong tree.
Ryckman attempts to restore the great physicist's reputation in his new book, Einstein, co-written with Arthur Fine, professor emeritus of philosophy at the University of Washington. The book is slated to be published by the Routledge Philosophers series in 2015, the centennial of the theory of relativity.
Ryckman is yet another crackpot idolizing Einstein.
"There is little mainstream research in the foundations of quantum mechanics," Ryckman said. "The reason is that most physicists consider it unproductive and not likely to be successful. This is the attitude that is taught to students."
There is too much research that is nothing more than rehashed disproved ideas.

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