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The Unpredictable Universe |
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Written by Staff Writer
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Feb 04, 2008 at 04:53 PM |
The clock spring is wound, the regulator releases its energy according to a certain inbuilt periodicity, brass wheels mesh finely with other brass wheels, and all the future states of this mechanism should be exactly specifiable. This is what makes it function as a timekeeper. We are not greatly surprised, though, to discover that it loses or gians a minute or two a week, which makes it plain that the specifiability is not as exact as all that.
Then one day it stops altogether. There was evidently a speck of dirt in the mechanism somewhere. One of the bearings has become a little worn. Well, we could have found the piece of dirt and worked out what it would do; we could have calculated the wear on the bearing. But we know that our predictivity is never going to be complete. We are never going to be able to isolate our clockwork completely from the other forces in the universe, or completely calculate the possibilities for wear and breakdown that lurk within it.
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Looking back from the present, the determinist says "I could in principle give you a causal account of everything about the present. All I should need to know is everything about the past." What possible meaning could be attached to this? It what sort of way could everything about the past ever be known? How big would this gentleman's head have to be? The answer is: bigger than you think, because one of the things that it would have to contain, among so much else, is his head. Then again, in what sort of words would the knowledge be expressed? In what sort of equations? Would these words, once uttered, these equations, once written, then become part of the world they were supposed to contain? In which case...
Looking forward from the present, the determinist assures us: "I could in principle give you a causal account of everything about the future. All i should need to know is everything about the present." All the same problems arise, of course; the only complete model of the present state of anything would be the present state itself. And what an incomprehensible mess that always is! Its unsatisfactoriness is well expressed by the yokel in the ancient but profound Irish joke who is asked by a motorist how to get to Kilkenny, and who replies :"Well, I shouldn't start from here." Excellent advice, that applies to so many aspects of life; think of allthe political reforms, all the scams and wheezes, all the human relationships, all the battle plans, all the schemes for doing anything, that might just possibly work if only you could start from scratch, with a clean sheet of paper, and not from the crumpled, scribbled-over heap of torn dog-ends which is all that ever comes to hand!
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There is another problem, too, about wholly specifying the present state of even the most limited system, never mind the entire universe; the present keeps dissolving into the past. In any case, there is always an element of arbitrariness, or at least of choice, in specifying the present state of affairs - or any other starting point in a causal system. This arbitrariness carries through the system, even in one as apparently closed and classical as a snooker table, so that our knowledge of the future position of the balls on the table at the end of a shot, even if we exclude the indeterminacy introduced by the uncertainties of the human performance in which the shot originate, must always remain more or less indeterminate. And in the highly volatile systems studied in chaos theory, where the smallest variations in initial conditions notoriously produce large differences in outcome, the significance of this inevitable arbitrariness of the starting point will be likewise magnified. The only entirely definite and not arbitrary starting point one can conjecture in the universe is the supposed starting point of the universe itself (which is always just a moment or two out of the cosmologists' range).
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In which case the only definite and non-arbitrary model of the universe is the universe itself.
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Last Updated ( Feb 04, 2008 at 04:56 PM )
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