I'm not necessarily talking about every possible computation being implemented by every physical system, just (at least) the subset of finite computations implemented by a physical computer or brain. I think this is another way of saying that a recording, or a single trace of a computation branching in the multiverse, can be conscious. To prevent a recording being consious yoiu can insist on counterfactual behaviour, but that seems an ad hoc requirement introduced simply to prevent the "trivial" case of a recording or any physical system implementing a computation.

Stathis Papaioannou ---------------------------------------- > From: [EMAIL PROTECTED] > Subject: Re: computationalism and supervenience > Date: Mon, 28 Aug 2006 15:38:23 +0200 > To: everything-list@googlegroups.com > > > > Le 28-août-06, à 07:42, Stathis Papaioannou a écrit : > > > > > Bruno marchal writes: > > > >> Le 26-août-06, à 16:35, 1Z a écrit : > >> > >>> > >>>> And since the computer may be built and programmed in an arbitrarily > >>>> complex way, because any physical > >>>> system can be mapped onto any computation with the appropriate > >>>> mapping rules, > >>> > >>> That is not a fact. > >> > >> > >> It would make sense, indeed, only if the map is computable, and in > >> this > >> case I agree it has not been proved. Again UDA makes such question non > >> relevant, given that the physical is secondary with respect to the > >> intelligible. > > > > Any computation that can be implemented on a physical system A can be > > mapped > > onto another physical system B, even if B has fewer distinct states > > than A, since > > states can be "reused" for parallel processing. If B is some boring > > sysstem such as > > the ticking of a clock then the "work" (not sure what the best word to > > use here is) > > of implementing the computation lies in the mapping rules, not in the > > physical > > activity. The mapping rules are not actually "implemented": they can > > exist written > > on a piece of paper > > Honestly I am not sure about that. > > > > so that an external observer can refer to them and see what > > the computer is up to, or potentially interact with it. And if the > > computer is conscious > > because someone can potentially talk to it using the piece of paper, > > ther is no reason > > why it should not also be conscious when the piece of paper is > > destroyed, or everyone > > who understands the code on the piece of paper dies. In the limiting > > case, the platonic > > existence of the mapping rule contains all of the computation and the > > physical activity > > is irrelevant - arriving at the same position you do. > > > OK, in the case the mapping rule can be coded in a finite way. > For example I can code the computation of any partial recursive > function by using a n-body problem. But a slight change in the initial > position of one of the body would destroy the information, and it is > not clear why some other *finite* working mapping rule would appear, > even in Platonia. Computation is a much constrained notion than people > usually realize. You may be right, but I have never seen any proof. The > probable reason for this is that such a proof would need a much more > formal approach to physics, including what happens in the bottom, but > nobody knows what happens there, and current theories makes big > simplification there (renormalization, etc.). > I think that what you say is not totally excluded by string theory, but > would be false with loop gravity, for example (in loop gravity > everything is quantized, and I can build, if only by diagonalization, > computation non mappable to any finite piece of loop-gravity-matter (if > I can say). > > Bruno > > http://iridia.ulb.ac.be/~marchal/ > > > > _________________________________________________________________ Be one of the first to try Windows Live Mail. http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---