-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Günther Greindl wrote: >> OK. So RR makes a prohibitive claim ... something like "living >> systems cannot be accurately modeled with a UTM because MR systems >> cannot be realized". And you are refuting that claim by a >> counter-claim that MR systems _can_ be realized, emphasizing that >> the recursion theorem is crucial to such a realization. >> >> Do I have it right? > > Yes that's basically my claim - RR also mentions his closed efficient > cause, that's where the rec. theorem comes in: you can code whatever > behaviour you like and then replicate it indefinitely.
OK. But you must realize that this is not really a _refutation_ or disproof. It's just one guy (Rosen) arguing with another guy (Günther). For an actual refutation (proof that Rosen's claim is false), you'd have to provide an explicit (effective) construction of a computational living system. And you haven't done that. [grin] Hence, you haven't proven Rosen wrong ... yet. ALifers across the planet are working on this constructive proof feverishly, of course. Or, you could show us specifically where Rosen's claim contradicts the recursion theorem. But to my knowledge nobody has formalized Rosen's work to the degree of specificity we'd need to show such a contradiction. I could easily be wrong about that, of course. So, if you'll point to such a rigorous formulation of Rosen's claim and precisely how it contradicts the recursion theorem, then we could say that one or the other (Rosen's or the recursion theorem) is refuted. > What is _not_ addressed in the (M,R) model is how it comes up in the > first place (= origin of life); Nobody (including the most zealous Rosenite, I think) would disagree with that. > that is where evolution comes in, and a machine model is at no > disadvantage here, again. It would be interesting to augment MR systems with some reasonably accurate formulation of evolution. - -- glen e. p. ropella, 971-219-3846, http://tempusdictum.com Almost nobody dances sober, unless they happen to be insane. -- H. P. Lovecraft -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFIEj5KpVJZMHoGoM8RAkx0AJ4ivFZFJgaCq9gdvoMWnbON3fnYzwCgqR/A tG+AVzNzHle0kEt6dKpDeww= =o6uQ -----END PGP SIGNATURE----- ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
