Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site brl-tgr.ARPA Path: utzoo!linus!philabs!cmcl2!seismo!brl-tgr!gwyn From: gwyn@brl-tgr.ARPA (Doug Gwyn) Newsgroups: net.philosophy Subject: Re: Electrons, etc., may TOO be deterministic. Message-ID: <3018@brl-tgr.ARPA> Date: Fri, 8-Nov-85 01:05:19 EST Article-I.D.: brl-tgr.3018 Posted: Fri Nov 8 01:05:19 1985 Date-Received: Sat, 9-Nov-85 06:15:45 EST References: <664@h-sc1.UUCP> <639@spar.UUCP> Distribution: net Organization: Ballistic Research Lab Lines: 99 > Please note in the first paragraph, I have specified `causally > deterministic mechanisms'. In accord with Hume's notion of `causality' > as a spatial and temporal conjunction between cause and effect, or > Einstein's notion as the propagation of influences locally through > spacetime, I believe it's fair to say that modern science has thrown the > classical doctrine of determinism (that present state is causally > determined by past effects) into the Humean flames. Unless prefer you > turn the word `cause' into swiss cheese, that is. Take your pick. Since when is Hume relevant to physics? His idea of causality is not necessarily correct; there have been serious criticisms of it. Certainly few if any theoretical physicists pay any attention to Hume's work. I was unaware that Einstein had such a notion of causality; could you provide a reference? Einstein believed in a form of determinism in physics, but I doubt he would have agreed with your attempt to define what it means. He was quite aware of the degree to which physical "laws" (theories, actually) constrain the behavior of systems and to what extent systems are not constrained by the laws. In the case of classical (non-quantum) field theories, he even developed a specific technique for quantifying this. Neither of the two items you mention preclude deterministic evolution of physical systems. However, quantum theory (if correct!) does appear to do so. > The 1982 Aspect experiment indicates we can toss more into those flames > than causal determinism. In particular, reductionism (the notion that > all phenomena can be completely understood by recursive analysis into > progessively smaller spatial and temporal elements) must be thrown into > the Humean flames, even on the macroscopic level, unless it can be > demonstrated that individual quantum events do not affect the high-level > behavior under study. Note that most of our machines can be understood > reductionistically BECAUSE WE DESIGNED THEM as hierarchical structures > whose behavior is determined by strictly causal connections and thus > relatively free of `unwanted' noncausal effects. No serious thinker proposes reductionism as you state it. Statistical physicists are quite aware of the problems. > Living things are notoriously nonhierarchical in their design, and I am > hardly alone in supposing that, during the evolution of life, nonlocal > interactions may have been put to use in very central organizing roles. > Frankly, I am not surprised that the problems encountered in the life > sciences have proven intractable to any primitive cause-and-effect > analysis that sees everything mechanistically. Mysticism has had even less success in the life sciences. Cause-and-effect does not imply mechanistic. To say that certain things happen acausally is tantamount to giving up any attempt to understand them. You may of course do so, but you should not call that "science". > Whether in anticipation of the results of the 1982 Aspect experiment or > not, during the past few decades or so, the sciences have been > liberating themselves from the sterility of 17th century dogma and rigid > reductionistic constraints that set the norms of classical physics as > THE standard of scientific excellence. QM paved the way. I doubt very much that many scientists from 1900 onward know what those dogma and constraints are. The so-called philosophers of science have been very slow to catch up. > I suppose it's understandable that computer professionals would > number among the last holdouts. Computers are, after all, totally > deterministic -- that is, until they break. But we shouldn't be blinded > to the world outside of our deterministic digital world. Dijkstra's classic "A Discipline of Programming" makes explicit use of nondeterminism as a tool for constructing correctness proofs for programs. > Some have misinterpreted Bohm's theories as a rearguard attempt to > reinstate the deterministic world of our forefathers -- this is > mistaken. Bohm insists that nature possesses an inexhaustible depth of > properties and qualities that no finite system of laws and categories > can ever express entirely; in particular, the universe has an infinite > number of nearly autonomous levels of explanation in which the natural > laws at any level must admit irreducible fluctuations which are only > explicable by the laws of that level's substratum; likewise, the > emergent properties of a higher level exist on their own terms and are > not totally inferrable from the laws of the substratum: This has been obvious to nearly everybody; no reputable biologist tries to ignore those attributes of reality that pertain specifically to his field but not to the supporting fields of chemistry or physics. Bohm really was trying to salvage determinism (but not that of our forefathers). There is much more that could be said to refute much of the mystical nonsense in the latter part of the article, but I tire of this. Could you "philosophers" PLEASE quit cross-posting this sort of stuff to the technical newsgroups such as net.math and net.physics?