Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 11/03/84 (WLS Mods); site astrovax.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!astrovax!elt From: elt@astrovax.UUCP (Ed Turner) Newsgroups: net.physics Subject: Re: Bell's Inequality (Reply to E. Brooks) Message-ID: <612@astrovax.UUCP> Date: Thu, 6-Jun-85 14:03:19 EDT Article-I.D.: astrovax.612 Posted: Thu Jun 6 14:03:19 1985 Date-Received: Fri, 7-Jun-85 03:12:48 EDT Distribution: net Organization: Princeton Univ. Astrophysics Lines: 76 >intuition). The theory was developed in the first place to correctly account >for experiments that could not be explained by classical physics. The theory >also reduces to classical physics in the appropo limit. The theory is not >broken! Lets not fix it until experimental evidence points out a need. > > >>I believe that this problem is recognized to be a real one by at least some of >>the experts (e.g., Feynman, Dyson, Penrose, Hawking, not to mention Einstein). >Why are you mentioning your beliefs here? Is this net.religion? Einstein >refused to accept the basic postulates of QM to day he died. I have had many >conversations with Feynman while at Caltech and I can assure you that he finds >the basic postulates of QM entirely workable. > This is my belated and probably final contribution to an exchange between Eugene Brooks and myself about QM which arose after an article I posted about the recent experimental verification of Bell's Inequality. Our discussion (or debate), a small part of which is reproduced above, has not actually had much to do with Bell's Inequality. 1) Basically, Dr. Brooks seems to be arguing that it is not wise, necessary, scientific, justified, or something to that effect to think about extensions, ellaborations, or alternatives to a physical theory which is in essentially perfect agreement with experiment (which I am willing to grant that QM is), particularly if one only seeks a more intuitive or aesthetically appealing theory. This "pure empiricism" is a common but (I think) minority philosophy of working scientists. In any case, I certainly disagree. Evidence for the effectiveness of intuition and aesthetics in the advancing science is very abundant in the history of science. To quote the most familiar (or even cliched) examples: Ptolemy's geocentric solar system explained the existing data much more accurately than Copernicus's prettier heliocentric model, and Poincare's aether drag compression theory explained the existing data exactly as well as Einstein's later Special Relativity. There was a very nice article in Physics Today several years ago discussing the role of beauty in physical theories which gave many less well known examples; I believe it was by S. Chandrasekhar. 2) I mentioned the list of emminent theorists quoted above not as an attempt to settle the issue by reference to authority (clearly inappropriate to net.physics) but rather to indicate that QM offends to some extent the intuition and physical aesthetics of at least some people who understand the theory very well and who could not be accused of having unsophisticated physical intuition. Note that I did not say that these people thought that "the basic postulates" of QM are unworkable (not likely since all of them have "worked" these postulates very effectively), merely that they had some intuitive or aesthetic misgivings about the theory. Since Dr. Brooks mentions personal conversations with Feynman at Caltech, perhaps I should add that my attribution of these views to the mentioned theorists is based on readings in two cases (Einstein and Penrose) and personal conversations in the other three (Dyson, Feynman, and Hawking). 3) One could easily cite other (and perhaps better) evidence that QM is not aesthetically or intuitively satisfactory. For example, many papers have been published about and whole conferences have been devoted to the physical interpretation of QM with authors/participants among the very best of the physics community. Great interest attends experiments such as the quantum nondemolition work at Caltech or Aspect's demonstration of Bell's Inequality that seem to throw further light on the fundamental interpretation of QM. Real disagreements about QM paradoxes (e.g., Schrodinger's cat) have remained unresolved for decades; a clear understanding of the mathematical and empirical content of the theory is not sufficient to resolve these paradoxes (unlike the Twin "paradox" in Special Relativity, for example). 4) It is still my opinion that the quantum theory of measurements (i.e., the collapse of wave functions phenomenon) is at the heart of the wide spread unhappiness of physicists with QM and that in some fundamental sense the theory is not complete. The Caltech work on quantum nondemolition which Dr. Brooks cites is fascinating and important but does not resolve the fundamental difficulty, in my opinion. Perhaps it is a step in the right direction though. My guess is that QM will eventually be superceded by a theory which has a more unambiguous physical interpretation with regard to measurements and perhaps other matters. It would be nice if this new theory were experimentally distinguishable from QM, but this might be impossible in practise or even in principle. Ed Turner astrovax!elt