X-Message-Number: 7993 Date: Wed, 02 Apr 97 12:52:56 From: Mike Perry <> Subject: Re: CryoNet #7985-#7992 Peter Merel writes, >Mike Perry writes, > >>A person is an FSM over finite stretches of time, but >>could also be a "growing automaton"--not limited to any >>fixed size if you take eternity into account. > >A growing automaton is an FSM? I take "finite state" to >mean, at the very least, recursively enumerable; how are >"growing automatons" recursively enumerable? I have made a confusing statement. A growing automaton is not an FSM--but behaves like one over a finite interval of time. And the FSM model is still useful in describ- ing reality, according to my understanding. It would only apply, strictly speaking, in localized domains. For instance, we could consider a bounded region of space over an interval of time (and this could be quite large, the whole known universe, for instance, but still it must be bounded). What is going on in that space (barring certain extremely weird possibilities) could be described by the behavior of an FSM which is subject to a sequence of inputs from the outside. The inputs need not conform to a computable se- quence, however, so the successive states of the FSM al- so would not have to be computable, if we suppose that time could be indefinitely extended, which we would have to do to raise the question of computability. (Finite sequences are always computable, and finite sets re- cursively enumerable.) Overall, it seems that reality can be described as an interconnection of FSMs--in- finitely many of them. I would call this "digital"--so our existence could be described as digital, even if the FSM model only applies locally. >>As for the quantum computer, it seems to provide a way >>of getting results that are hard to explain unless you >>assume many, many computations are being done in >>parallel--a suggestion that many-worlds is true, i.e. the >>extra "worlds" really exist. (I'm not saying that all other >>interpretations are ruled out, however, but clearly the >>others have some explaining to do.) > >Weeelll, for Cramer, just as the cat is not truly in a >superposition, neither are the qbits; instead, you've got the >standard atemporal TI mechanisms linking the >measurement of the result with the initialization >of the computer. Since the TI doesn't suggest any >different result than the maths of QM, there's no great >mystery in this. Okay, I have to acknowledge that other interpretations than many-worlds do make the same predictions mathemati- cally, and we must look harder for tests to distinguish them. More work would be needed to justify a claim that a successful quantum computer would "prove" many-worlds over its rivals. To me it still "tends to support" many worlds because that seems to provide a straightforward explanation of what is going on, and I have doubts about the other interpretations with their non-locality, atemporal- ity, etc. I also wonder about possible, unsuspected equiva- lences among the various interpretations. To me it seems entirely possible that two very different-looking interpreta- tions could be equivalent at a deep enough level that both could be accepted, for philosophical purposes, as true. >>here is what Michael C. Price had to say (17 Feb. 1995, >>"Many-worlds FAQ," >>http://www.airtime.co.uk/users/station/m-worlds.faq): [snip] The Cramer TI interpretation has some prominent physi- cists supporting it, just as many-worlds does. I'll try to get in touch with Mike Price to see what he has to say. A few other comments: I've also read that many-worlds is the only version of QM that allows quantum gravity. Anybody know anything about this? Tipler in *The Phys- ics of Immortality* says (p. 170): "Of course, the Many- Worlds Interpretation may be wrong; many physicists think it is. But the overwhelming majority of people working on quantum cosmology subscribe to some version of the Many-Worlds Interpretation, simply because the mathe- matics forces one to accept it." Finally, Nick Herbert in his well-known book *Quantum Reality* (1985) makes a mistake in his discussion of many-worlds. On p. 242 he says, "Although Bell's theorem does not apply to an Ever- ett-style [many-worlds] universe, there's plenty of non- locality present without it. Any model of reality in which a tiny event in the Andromeda galaxy can instantly split my reality into thousands of Xerox copies cannot by any stretch of the imagination be called 'local.'" The mistake here is that this assumes the split propagates instantan- eously--but actually it is not necessary to assume it propa- gates at more than light speed--locality is preserved. [snip] >For a look at all of the surviving interpretations, you >might try > >http://ring.aist.go.jp/archives/misc/NetNews/FAQandDOCS/alt.sci.physics.newtheories/Measurement_in_quantum_mechanics_FAQ Thanks for the reference re Thomas Donaldson Thomas questions whether mathematics would be universal to "advanced" aliens, and uses this to call into question my idea of a universal language. To me the potential, at least, to develop mathematics to an arbitrary level is a prerequi- site for being considered "advanced"--impose a ceiling of some kind and your aliens are forever limited and fail what I would consider a crucial test of being "advanced." In particular the aliens should, after sufficient advancement, understand the concept of computable function and should have general-purpose computers, equivalent to a universal Turing machine. One trend in our own civilization is that mathematics is a cumulative enterprise--branches once developed do not lose relevance or interest over time, even when we find them inadequate in certain circumstances, as with Euclid- ean geometry. This argues against the thought that some- day we might "forget" something we now consider impor- tant, such as the prime numbers or computable functions. It also suggests that alien civilizations would, given sufficient time, master the same mathematics we have mastered, and retain this knowledge once acquired. Thomas also wrote, >I am doubting the Turing Test, not just as a test of >consciousness but as a test of intelligent behavior. To me, passing the Turing Test would demonstrate intelli- gence. This doesn't mean "demonstrate it in all possible ways" however. Thomas, is this what you had in mind? Mike Perry http://www.alcor.org Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=7993