On 23 Apr 2002 at 18:56, Tim May wrote: > On Tuesday, April 23, 2002, at 11:18 AM, Ken Brown wrote: > > Back nearer to on-topic, Tim's explanation why the world could not be > > predicted even if it were locally (microscopically) predictable sounds > > spot-on. > > It's not my idea, obviously. But the fact that I wrote it so quickly, > and so glibly (he admits), is because it's so internalized to everything > I think. I simply cannot _conceive_ of anyone thinking the Universe, let > alone the Multiverse, is predictable in any plausible or operational > sense. The sources of "divergence" (aka chaos, aka combinatorial > explosion, aka Big O with a Vengeance) come in from all sides.
I can explain why people might think it were. You could imagine that due to feedback mechanisms or statistical averaging, these small uncertainties tend to cancel each other out, provided you're confining your interest to macroscopic observables. For example, when a sheep dies you get more grass for the remaining sheep, which gets you more sheep again, so you can do a reasonable job of predicting sheep population without knowing anything about the fates of individual sheep. Similarly, if i cut a fart in an elevator, there's no telling where an indvidual stink molecule will go, but in not too long they'll be more or less uniformly spread throughout the elevator. I can't see how anyone would believe you would ever be able to predict, say, radio static. But I think 50 years ago most people believed that in principle you could predict the weather arbitrarily far into the future. And there are still people who believe you can predict stock prices based solely on the squiggles. These people are called "technical traders" by themselves and "fools" by others. George > > --Tim May > "He who fights with monsters might take care lest he thereby become a > monster. And if you gaze for long into an abyss, the abyss gazes also > into you." -- Nietzsche > >
