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. Even the Fredkin/Toffoli/Wheeler stuff (and E. Leitl sent me a note saying he thinks the reference to predictability was about Fredkin's "Digital Philosophy" stuff...maybe, maybe not) does not escape the impasse of unpredictability. For reasons I will not even belabor here...those who don't see it already won't be convinced even if I and others write a dozen long articles. On to Ken's point about Merrye Olde England. The U.K. has long been a hotbed of quantum and cosmology things, from Dirac onwards. (I started to list the cosmologists, but bogged down trying to remember all of them...Hoyle, Bondi, Penrose, Hawking, etc.) It turns out I've been reading a lot of quantum theory related to the interest I talked about a few weeks ago, namely, category theory and topos theory. And there's a fascinating link with quantum cosmology and quantum mechanics in general. I'll reference a lecture given in honor of, believe it or not, my professor of relativity back in 1973; Jim Hartle. Chris Isham and his collegeague Butterfield are applying topos theory to the problem of observables, logic, and apparent paradoxes in quantum mechanics. An excellent lecture is downloadable in Media Player/Quicktime form at http://www.newton.cam.ac.uk/webseminars/19990902-isham/ "Quantum Theory and Reality" is the theme. It's worth watching. About half way through, Isham has an astounding graphic showing how the natural topos of quantum mechanics naturally gives us the Schrodinger's Cat situation, showing that how natural it is in this topos (this "mathematical universe") that the Law of the Excluded Middle (A or Not-A) be ignored. And, as I told you a few weeks ago, there are even connections with themes of this list. But the margins of this thread are too narrow and I regret that I cannot say more at this point. --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
