Thursday, May 28, 2015

EPR was not a sleeping beauty

Lubos Motl writes:
Nature wrote an article with the list of top 15 "sleeping beauty" papers that were initially almost ignored but many decades later, they exploded and began to attract lots of followups.

Almost all of them are about the physics of surfaces and closely related issues in solid state physics. One exception, ranking as the #14 sleeping beauty, is the Einstein-Podolsky-Rosen 1935 paper ...

It's funny because the 100% unjustified and self-evidently incorrect assertion "no reasonable definition of reality could be expected to permit this" is the central point that decides about the validity or, in this case, invalidity of the whole paper. This is the point of the paper saying "here a miracle occurs". Quantum mechanics changes our notions of reality in such a way that exactly the "forbidden" insight is true and fundamental in the whole theory: the reality always depends on the observables we can make, and realities of noncommuting observables are always mutually exclusive.
Motl is right about this.

People commonly praise this 1935 paper as if it pointed out some profound flaw in quantum mechanics, or as if it opened the way for quantum information/cryptography/computing. It did not.

All it did was to draw attention to an aspect of quantum mechanics, and declare it unreasonable.

It was the belief of Bohm, Bell, Clauser, and others that Einstein had the germ of an idea that might be turned into an experimental disproof of quantum mechanics. If they had turned out to be right, then this would have a very important development. But it was not right, and the quantum mechanics of 1930 has held up.

1 comment:

  1. "...and the quantum mechanics of 1930 has held up. "

    for toy systems.

    In the real world, Density Functional Theory is the real work-horse and it is a pile of crap. There are a zillion density functionals out there and there is no such thing as an expert on the subject because it is rife with confusion.

    Why doesn't Wile E. Motl, supergenius, end his current career of being a fantasist and go save those poor souls.