Article View: sci.physics
Article #4550I'm no radical
From: John C. Baez
Date: Sun, 04 Oct 1992 22:35
Date: Sun, 04 Oct 1992 22:35
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Paul Budnik writes: >In article <1992Oct2.202249.21453@galois.mit.edu>, jbaez@riesz.mit.edu (John C. Baez) writes: >(Budnik writes:) >> >But my formalism makes the same predictions of quantum mechanics with >> >the exception of tests of Bell's inequality. >> Let's see your formalism - where are the equations? What precisely does >> it predict in situations where QM violates Bell's inequality? Not >> words, numbers. Show how to do some QFT-type calculations using this >> formalism (since QFT combines relativity and QM) - say electron-electron >> scattering. >If I could do that I would not be wasting my time posting this stuff. I >would be publishing it and patiently waiting for the Nobel committee to call. >I should not have said `my formalism'. Yes, that was my point. I think your ideas are interesting enough without having to oversell them. Overselling them will attract crackpots but repel the sort of people you might want to become interested. You have a rough idea for an alternative formalism. Very few people who might have the chops to turn it into a working alternative to QM are likely to be interested in spending their energy on such a project, which has (IMHO) a very low chance of success. Of course, you think it has a high chance of success and are trying to convince others of that. If you don't have the ability to turn your ideas into a fully functioning formalism, I guess that's a good approach. Even better would be convincing or paying someone to do the crucial experimental test of Bell's inequality. (I should add that I have simply been taking your word all along on the claim that existing tests fail to ensure spacelike separation. Shows how nice I really am. :-)) I should emphasize though, that until you spend a lot of energy trying to turn your ideas into a real formalism, you will never really know how reasonable they are. >The alternative to the existing theory >I am proposing is to add locality as an additional constraint to that >theory. This implys that we do not know how the wave function changes >before and after an observation. The multiparticle wave function cannot, >in general, change in a local fashion when an observation is made, but that >is not the issue. It must change in such a way that there are no nonlocal >macroscopic effects. No one knows how it does change. I think it is a >chaotic-like process that cannot be modeled by an equation. The underlying >laws can be modeled and the whole process could in theory be simulated on >a computer. But one cannot give a simple equation that models this behavior, >Just as one cannot give a simple equation that models the atmosphere in >enough detail to predict the weather. That can only be done to >a limited degree by large scale simulations. >A few months ago you gave an argument why quantum mechanics may not be >completely valid at very small distances. Huh?? I never gave anything of the sort, although I can imagine what you are referring to. I am more worried about your tendencies to overstate things when you are describing MY work than your own. In any case, let me state that I am working on the assumption that quantum mechanics is completely valid at very small distances, simply because I see no evidence against this, and a huge amount of evidence for QM in general, together with its tremendous mathematical elegance. >You do not have an alternative >theory worked out. You would like to develop such a theory that combines >gravity with QFT but you know it will be hard problem and take a long time. >I do not think you expect to be able to do it by yourself. Let me clarify what I was referring to. Typically in quantum theory the inner product is fixed by the requirement that symmetry groups act unitarily, together with the requirement that the Hamiltonian be nonnegative. In quantum gravity it is well-known by now that neither of these requirements are applicable, at least when space is taken as a compact manifold, say S^3. I have developed a mathematical formalism whereby certain "nonnegative" states of quantum gravity on S^3 determine Hilbert spaces for "quantum gravity on D^3", where D^3, the closed unit ball, is one of the halves of the S^3. This is rather radical because of the state-dependence, and I imagine that's what you're talking about when you say I'm claiming that "quantum mechanics is wrong on small distance scales." However: 1) I am not proposing dropping what I see as the key principles of quantum mechanics, namely the use of Hilbert spaces to calculate probabilities via inner products. To do so in the absence of compelling experimental evidence would be nuts. 2) I have worked out a mathematical formalism which led me to this notion. It is only because I have worked out lots of the details that I have dared mutter anything about such ideas on sci.physics, and even so, I believe that in my original post I said "take this with a mongo grain of salt." 3) This formalism, far from being all my own, is simply the result of applying ideas from knot theory and Chern-Simons gauge theory to the Ashtekar-Rovelli-Smolin loop variables approach to quantum gravity. The latter approach, I should add, is extremely conservative in that it is simply using a change of variables to simplify the constraints that typically make quantum gravity so hard. It is not, like string theory, a whole new theory - it simply combines quantum mechanics and general relativity in a mathematically clever way. 4) I'm not working on my own; I'm constantly checking my ideas with people who know infinitely more about general relativity than I do, and I'm submitting papers to refereed journals and rewriting them to correct errors and tone down any unsupported claims. In short, I am not doing anything nearly as radical (hence likely to fail) as you seem to think. I think that, in the absence of compelling experimental evidence, it is best to take a conservative approach. The above is sort of an over-reaction to Budnik's remark, but I think it's important for people not to get an over-romanticized notion of how progress in science typically works. >Tests >of locality can be done using existing technology. Perhaps you should >consider changing your area of research. :-) Alas, I'm a mathematician, not an experimentalist. I had enough trouble trying to light a Coleman stove last weekend.
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Newsgroups: sci.physics Path: arc1-ca.pugleaf.net!sparky!uunet!haven.umd.edu!darwin.sura.net!spool.mu.edu!sol.ctr.columbia.edu!eff!snorkelwacker.mit.edu!galois!riesz!jbaez From: jbaez@riesz.mit.edu (John C. Baez) Subject: I'm no radical Message-ID: <1992Oct4.223546.9969@galois.mit.edu> Sender: news@galois.mit.edu Nntp-Posting-Host: riesz Organization: MIT Department of Mathematics, Cambridge, MA Date: Sun, 4 Oct 92 22:35:46 GMT Lines: 123