Against the Copenhagen interpretation of quantum mechanics

[Daymare17]

Hello, this is my first post on the new forum (great design BTW).

 

I am a Marxist and I am also very interested in science. The site of my tendency recently carried an article about quantum mechanics. It criticises the mystical and irrationalist trends in modern science in general, and the Copenhagen Interpretation of quantum mechanics in particular. The writer is a layman and has probably not had access to much scientific debate. Can any of you criticise the article? I'm sure it has very interesting points even for anyone who's not into politics at all.

 

http://www.marxist.com/quantum-mechanics-copenhagen130705.htm

[CraigD]

… Can any of you criticise the article? I'm sure it has very interesting points even for anyone who's not into politics at all.

I think Neilsen’s article presents a decent summary of the background of quantum mechanics. However, his characterization of the Copenhagen interpretation as a purposeful attack on dialectic materialism strikes me as disingenuous and ad hominem: while many early 20th century physicists were politically opposed to world socialism, I believe that the various interpretations of QM, of which the Copenhagen interpretation is not the only, not the first, nor, arguably, at present, dominant, have been proposed to promote progress in Physics, not attack any particular political system.

 

The article also makes distinct errors in theory: for example, the assertion that bubble chamber data violates uncertainty.

 

The Afshar experiment, is, I think, the article’s most credible argument that not just the Copenhagen interpretation, but most of quantum physics, may be incorrect. While legitimate, controversial, and thought-provoking, the Afshar experiment is very new (3/2004), tentative, and entirely contradicted by many “quantum eraser” experiments that support the theory of complimentarity. In citing it, I believe Neilsen is grasping at straws in order to support his article’s thesis.

 

At its core, dialectic materialism holds that reality is objective, not social, and is best defined by science, not political criticism. Although quantum physics has effectively overturned much classical physics, it is not a subjective, phenomenalistic theory. Although its underlying formalism is not as intuitive as classical physics, it is equally formal and deterministic.

 

To those with a good understanding of it, including, I strongly suspect, its originators, the Copenhagen interpretation has always been considered tentative and pragmatic. Increasingly, QM formalisms in which measurement has no “spooky” role in decoherence, are emerging, and appear supported by recent experimentation, particularly in the area of quantum computing. In general, these new theories “banish the ghosts” by recognizing that everything in the universe according to quantum physics is a quantum physical system, including “conscious observers”.

 

For an example of modern, non-Copenhagen interpretations of decoherence, I recommend http://gregegan.customer.netspace.net.au/SCHILD/Decoherence/DecoherenceNotes.html. While actually part of writer Greg Egan’s site supporting his science fiction novel “Schild’s Ladder”, it presents real Physics in a insightful and accessible way.