X-Message-Number: 4792 From: Date: Thu, 17 Aug 1995 19:39:27 -0400 Subject: determinism Relatively recent posts have expressed opinions on determinism and its implications. One view is that, (a) even given determinism, there may be no uniquely inferrable past (or future); and (b) even if the past were uniquely inferrable in principle, in practice not much could be done because of great sensitivity to errors in starting observations. Both these ideas seem to rest on an oversimplified view of inference. In the simplistic view, the inference model is akin to trying to chart an asteroid path: an irregular body of relatively small mass, influenced gravitationally by many larger or comparable masses, is indeed very hard to track for long, using only the law of gravitation. But any postulated future inference engine would have many more resources. Bodies act, interact and react not only gravitationally but in many other ways, including emission/absorption/scattering of photons and perhaps including non-local quantum effects, maybe tachyons. Taken together, these would almost certainly narrow down the possibilities to just one. Hans Moravec reportedly has a similar view--that a person could be inferred, even in the distant future, from clues in the environment, the footprints he left in the sands of time. I agree (for a change). As to the validity of determinism, I rely again on the sweep of history, in a certain sense. The whole thrust of the advance of science is that things make sense if we look hard enough, that effects are preceded by (or at least linked to) causes; and also that Newton's Third Law can be generalized: there are no one-sided actions, but only interactions. And if everything reacts with everything, then indeed information is never lost. The current prevailing I-surrender-Dear interpretation of quantum mechanics seems to accept a partial randomness in the universe, but I cannot see that a true "randomness" (an objective randomness, not grounded just in the accidental ignorance of the observer) has any MEANING, let alone any possible reality. It is conceivable, of course, that the hidden variables are truly hidden forever from our ken, more or less as fire is hidden from fishes, just by our physical limitations as a species or by our three dimensionality; but any FUNDAMENTAL randomness is just a nonsense term that is given a spurious air of meaning by the misuse of language. Think of the quantum rules governing statistical distributions of certain quantities. An actual observation produces a "random" result--but all of these build up to a definite distribution. So we have "random" events that nevertheless follow a definite overall PATTERN. Are RANDOM events supposed to have MEMORIES or GUARDIAN ANGELS that warn them not to stray too far, too often? Quantum mechanics (in the common interpretation) requires orderly randomness! Stuff it. As for many-worlds, I have problems with that too, but that's another long story. Robert Ettinger Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=4792