X-Message-Number: 3118 Date: Mon, 12 Sep 94 03:50:41 From: Subject: CRYONICS -- Determinism Determinism: some more thoughts Mike Perry, 12 Sep. 1994 Bob Ettinger and others have commented recently on "determinism" vs. "nondeterminism." I'd like to summarize my understanding of the main points, then offer some thoughts that others may not have considered yet. In a deterministic universe, the future is completely determined by the present. In a nondeterministic universe there are "random" events that cannot be predicted from the previous condition of things, e.g. some future event could happen that could not be foretold in advance, even with perfect information about the state of everything. Some (and Bob in particular) find the notion that truly random events happen unscientific and (as I gather) essentially mystical, something then that would be disallowed by the premise that events can be fully explained by some scientific theory. Bob in turn is confident that the scientific rather than the mystical holds sway in our existence, thus the universe will eventually be found to be fully deterministic. An additional property, not guaranteed by determinism, would be what could be called "reverse-determinism"--that the past (rather than the future) is completely determined by the present. As has been pointed out the one does not necessarily follow from the other; however Bob has expressed some confidence that even reverse-determinism will hold. If this is true it will mean that every person who ever lived can be resurrected (that is, we should be able to reassemble the particles that composed any past individual in the correct order, or at any rate, recover a complete description from which a functioning duplicate person could be built). It would also mean that cryonics, in an ultimate sense, is superfluous, though it still would presumably be advantageous because you would come back *sooner*, and perhaps gain other advantages, if your remains had not disintegrated. Sometimes the opinion is also expressed that *unless* a sufficiently complete description of a person can be recovered from surviving information, that person is gone forever or cannot be resurrected. For those who doubt reverse-determinism, then, cryonics may be the only hope for a life after clinical death (though I have a different viewpoint). In any assessment of reality, of course, the final arbiter is reality itself. There was a time when the universe did seem unquestionably deterministic, but in the 20th century, quantum uncertainty seems, on the face of it, to abolish that possibility. A leading theoretician, John von Neumann, "proved," on the basis of quantum mechanics, that uncertainty was built into the fabric of reality, and could not be eradicated. However, eventually this "proof" was shown not to be airtight, and under certain conditions determinism could still hold. One other property had to be sacrificed, however, that of locality. Locality means that a given event is not influenced by events that are happening more-or-less concurrently, but at great distances away. With nonlocality you have "spooky action at a distance" or interactions of concurrent processes that are arbitrarily far apart. (The allowable interactions are not arbitrary, however, and do not, for example, allow passing of messages back and forth at greater than light speed.) By now the spooky action at a distance has actually been verified (to most persons' satisfaction), as in the Aspect experiments with paired, correlated photons. The universe, then, may be deterministic. It does not follow, however, that we can, even in principle, make arbitrarily accurate measurements of some sort, and predict gigantic chunks of the future to subatomic precision, or similarly retrodict the past. Where hidden variables are involved, they may remain forever hidden. To make a prediction it is not sufficient that the determining information exist, it must also be available to the observer. It is possible then that determinism holds in some absolute sense, avoiding the imputation of mystical underlying causes, but in practical terms, the universe is randomizing nonetheless. This state of affairs I'll call "inaccessible determinism." I've now surveyed some opinions of others, and will offer some of my own. Some of these are rather wild speculations; I hope they will be interesting enough to be worth a read. In general, I lean toward inaccessible determinism. I am optimistic, however, on the possibilities of ultimately resurrecting persons from the remote past, though guardedly. It's better to be frozen than not, if you have the choice. Some interesting possibilities may exist for reconciling seemingly incompatible world views such as Many Worlds vs. One World. On the face of it, it seems too tall an order to me that the entire past history of the cosmos, down to subatomic dimensions, could ever be retrodicted. I know of no procedure, for example, that seems remotely capable of mapping the molecular structure of an ice cube, after the ice has melted. Basically, whatever information is straightforwardly captured in written records, fossils, etc., is all we're ever going to get. No doubt with nanotechnology a great deal of previously unknown information will come to light, and it will be exciting times, but I doubt if such things as, say, even the names my 1,000th-generation ancestors will be recoverable. (This would take us back to around 20,000 BC, well before the invention of writing!) The only hope for resurrecting a person once obliterated, as I see it, is a series of lucky guesses that restore the necessary information. This is a very, very remote possibility, by any ordinary standards. For example, if 10^12 bits are sufficient to characterize a person, and we have nothing else to go on, it will take 2^(10^12) guesses to arrive at the correct sequence of bits from which a functioning duplicate person (equivalent to the original and qualifying as a resurrection, in my view) could be constructed. This seems preposterous, but is far from ruled out if time and space are infinite. We may never know if we have found the correct sequence, but that does not rule out finding it anyway. There is more to say on this subject in view of a Many Worlds cosmology. Basically, the viewpoint of Many Worlds is that the universe as we know it is far from all there is--there are in fact parallel universes in which events are happening that are similar but not identical to our own. Whenever a "random" event happens, even on the smallest scale, the whole universe splits into near-identical copies in which this same event happens in different ways, enough universes to completely exhaust all the possibilities. So in reality there is no randomness, but metaphysically this is preposterous! What process could give rise to whole universes on such short notice? On the other hand, who said reality had to fit our preconceptions? Despite the metaphysical difficulties Many Worlds has some attractive features, e.g. observations can be explained without invoking an observer that not subject to quantum processes (a bug with most other theories). There are also ways of effectively getting Many Worlds without the incessant creation, e.g. supposing infinitely many worlds *already* exist side-by-side, some of which are so closely correlated as to seem identical, until a "random" event happens differently in different worlds, effectively splitting them apart. In addition to splitting apart, it appears worlds can be joined together, by what we perceive as information losses, e.g. the melting of an ice cube. Suppose at the start there are many similar worlds, each with an ice cube. On the macroscopic level the cubes appear identical but ultrastructurally they are different (and detectably so), effectively separating each world from the others, Melt the ice, however, and this distinguishing information is (arguably) lost, effectively joining the worlds, or some of them. How would Many Worlds affect the prospects of resurrecting previously obliterated individuals? Mainly, by enlarging the possibilities for success, and by greatly reducing the time expected to achieve any given resurrection. This would follow because (a) more than one historical timeline is authentic, and (b) more than one resurrection process would be expected to be in progress, if we ever reach the point of trying one ourselves. Basically, every world has its own, distinct historical timeline. A case can be made in fact that substantially every possible history is happening in parallel. So not many guesses may be needed (perhaps only one) to recreate a person from *some* real past. (And with Many Worlds, there is not just one version of "our" past but more than one with equal claims of authenticity.) On the other hand, if a resurrection project is ever started (as might be the case in a few centuries or millennia) one would expect a great profusion of similar processes in other worlds. Any given, real person, once obliterated, could then expect to pop up somewhere amidst all the attempted reconstructions. To me it would seem sensible, not to just try for individuals, but for entire histories of individuals stretching far back into the past. More bits to guess, but the same considerations would apply. It would make sense (the first time around at least) to reconstruct a history that perfectly fit the surviving records, which by then we could assume had been totally exposed through nano-archaeology. A resurrection of this sort, i.e. involving lucky guesses, is different from one that could be carried out straightforwardly, if we had enough information to start with (as we hope will happen with cryonics, for example). With lucky guesses we will never "know" when we have the person; such persons will be separated irremediably from verifiable history. To me that is significant. I would rather be part of verifiable history if I could; this essentially is what survival is all about. I would settle for an alternative if I had to (i.e. if I died and couldn't be frozen); better to be present in some sense than not at all, but then I'd want to survive for the *rest* of eternity, at least. So it's better to be frozen, than obliterated. Another reason for being frozen is that you'd certainly expect to come back sooner, even if the parallel resurrections were eventually going full tilt, as I've indicated. There are other interesting possibilities. Those that did the resurrecting would presumably be strongly immortalist posthumans, who we can assume will come to dominate the future. If I were such a being, I might create the *potential* for regenerating an entire, multigenerational population of earlier beings, by generating the necessary information, long before I'd want to use that information to actually resurrect some specific being. The ones I'd be most interested in resurrecting early on, by far, would be rationally, strongly immortalist themselves. (A few other attributes would help too, e.g., decency, kindness, love of fellow beings, etc.) I think I would have a lot of empathy with that sort of person, even if they were primitive by my standards, but considerably less interest in those who really didn't have it together that way. If this is any indication of what the future actually holds in store, and you would like to be resurrected relatively soon, you'd better be strongly, rationally immortalist right now. This means, of course, being a signed up cryonicist! If you aren't that way, then you may reappear someday, but rather remotely, and in some latter-day counterpart of a mental hospital, where you might have to spend a long time (subjectively at least, maybe in actuality) before you could reasonably take your place in the world. Many Worlds is a viewpoint I favor. Partly it's just because I like it--it seems to provide the best scenarios of resurrection in the tough cases, i.e. after obliteration, assuming the hidden past will never be recoverable in the usual sense, which I think is likely. But also it actually seems to be viable from a physics point of view, in ways most alternative interpretations of reality are not. (Sometimes the complaint is raised that no experiment can distinguish between Many Worlds and alternatives, but while this has been true up to now, there are some apparently viable future possibilities.) Some alternatives exist to Many Worlds, however, that avoid the problem with the observer I mentioned earlier. One of these that has attracted interest recently is a theory of David Bohm (*Scientific American* May 1994 p. 58). This is a fully deterministic theory, but has nonlocality. It is a One World, not a Many Worlds theory. It is also, relative to other, comparable quantum theories, quite simple, which itself is a reason to give it attention. So now I'll offer another wild speculation: the (possible) reconciliation of a One World, nonlocal theory with Many Worlds. Basically, while there is really One World, there are Many Large Pieces of that world, connected by nonlocality, and interacting in such a way as to effectively constitute Many Worlds. Our known universe would be one Large Piece, for instance. Somewhere there is something else very similar to that, and somewhere else something else very similar, etc. In all of (possibly infinite) time and space there are many possibilities. Sufficiently similar pieces would interact nonlocally, that is, instantaneously at a distance. The how and the why (or the whether, for that matter) I don't know, but I think (and hope) this bears looking into. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=3118