Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!seismo!mcvax!lambert From: lambert@mcvax.UUCP Newsgroups: sci.physics,sci.philosophy.tech Subject: Re: Yet Another EPR Question Message-ID: <7407@boring.cwi.nl> Date: Thu, 4-Jun-87 02:52:07 EDT Article-I.D.: boring.7407 Posted: Thu Jun 4 02:52:07 1987 Date-Received: Sat, 6-Jun-87 06:35:37 EDT References: <422@telesoft.UUCP> <1205@batcomputer.tn.cornell.edu> <7400@boring.cwi.nl> <5925@brl-smoke.ARPA> Reply-To: lambert@boring.UUCP (Lambert Meertens) Organization: CWI, Amsterdam Lines: 72 Xref: utgpu sci.physics:1491 sci.philosophy.tech:140 In article <7400@boring.cwi.nl> lambert@boring.UUCP (I) wrote: >> Here is another many-worlds interpretation of the Aspect experiment than >> the usual one. It requires no "supra-luminal collapse" of the wave- >> function and is in fact pseudo-deterministic. [...] >> Question: does this predict something different from QM? In article <5925@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) ) replies: > No. The "many-worlds" interpretation has been known for quite some > time to make the same predictions as the Copenhagen interpretation. Has this been shown then for *all* many-worlds interpretations? Or is there some obvious bijection between the one I gave and the well-known MWI? (In the usual version the world "forks" on the *current* *observation*; in the one I gave on *future* *experiments*.) One of the things I don't understand with the usual MWI is how it gets the probabilities right. An observing consciousness on a branching path has a history of say L and R turns; why should there be (in the case of a replicated experiment with bias) more of one sort than of another? > It also seems to lack any real explanatory advantage. A philosophy.technical point: Even if two theories are isomorphic, it may be the case that one admits of or even invites certain variations that the other does not. It may then be the case that with a subtle variation (one that predicts the same observations within experimental precision on the repository of past experiments) an "unorthodox" theory is suddenly isomorphic to yet another, possibly much simpler (that is, elegant), theory. The time has come then to start thinking of experiments for which the orthodox theory and the new one predict different outcomes. Some people seem to think that it is a waste of time to speculate on variations of orthodox QM since it has withstood all attempts at experimental falsification with an untarnished record. It seems extremely unlikely to me that this state will extend forever into the future. What is more important, new theories do not seem to spring forth from experimental falsification of old theories, but are dreamt up by original thinkers dissatisfied with the inelegance of those theories. For example, it is now known that Einstein was already (unsuccessfully) working on a theory of relativity before he knew of the Michelson-Morley experiments, driven by esthetic considerations. I find QM as it stands UGLY. This is not because I cannot "understand" it in terms of a macroscopic model with bouncing balls or jelly, but because it has a built-in *irreducible* casino, while we know now how little it takes to get chaotic behaviour as an emergent property from deterministic non-linear dynamic systems. I refuse to be convinced that there is not some (predictively almost identical) theory that does not suffer from this. And I do not mean ugly hacked variations of orthodox QM, but a conceptually truly different theory. One of the kind of things I am speculating about is that the world as observed is just a projection on a space of "observables" of the "true" world. I *know* that this is mathematically the same as introducing hideous variables and thus would be falsified because of Bell's inequalities. But maybe we are locked into a certain way of looking at all kinds of theories that causes these inequalities to be applicable, and are overlooking an obvious other kind in which an essential assumption in their proof does not hold. Unfortunately, I know too little of QM, QCD and what not to be able to speculate fruitfully about all this (and cannot find the time to take this subject seriously up), and, moreover, I am not Einstein. Still, I find thinking about this intellectually stimulating, and I for one have learned a lot more from the discussion in these newsgroups than from all kinds of popular books on QM combined. -- Lambert Meertens, CWI, Amsterdam; lambert@cwi.nl