Subject: Re: Hawking, Penrose: Our universe, highly unlikely. Date: Tue, 14 Aug 2001 15:07:54 -0700 From: "Brian Holtz" To: "Paul Filseth" wrote: > What I remember Poundstone saying was that someone had > shown it's possible to build evolving patterns in Conway's Life By showing that Life supports Turing machines, or by some other more direct method? I've heard of no other such method. So again: if your claim were merely about the theoretical possibility of artificial life in a Turing machine, then it seems disingenuous to instead invoke the simplistic physics of Life and its menagerie of 2-D geometric critters like puffers and floaters, when a Turing-on-Life organism would not be such a 2-D self-contained pattern. It seems more direct to say that Turing machines are believed to be capable of supporting patterns that reproduce and evolve. > > and in effect is meticulously designed to exhibit natural selection. > > Mainly that means it's designed to be fault tolerant, so > a mutation doesn't cause an instant program crash. No, I mean in particular the very fact that it (I think) time-slices each organism like a thread or a process. Systems like Tierra or Core Wars that maintain a program counter for each organism are much more nurturing universes than are true cellular automata or our physical universe. > Surely you're not suggesting that if we knew > for a fact that some other set of laws would support life, that means > those laws wouldn't count, since then they aren't "bio-agnostic"? I'm suggesting that a universe which keeps track of the program counter of its every organism is not nearly as bio-agnostic as ours. -- Brian.Holtz@sun.com Knowledge is dangerous. Take a risk: http://humanknowledge.net