On Mon, May 11, 2015 at 10:36:55AM -0700, meekerdb wrote: > On 5/11/2015 12:14 AM, Bruce Kellett wrote: > >Bruno Marchal wrote: > > I think this obfuscates the point. One says yes to the doctor not > because one's conscious thought is a computation, but rather because > the doctor proposes to replace part of your brain with something > that will perform ALL the computations that part of the brain could > do. It is not that consciousness is a computation, rather it is a > class of computations that will map all possible (not just actual) > environmental inputs into outputs. And that's why a recording is > ruled out - whether it would be conscious or not; it is not > counterfactually adequate. >
I do think this insight is important, but it does require more explicit treatment than simple dismissal along the lines of "a recording is not a computation". > Whether the ultrafinitism is > true or not, our theory of the world and consciousness should not > depend on there being infinities. So within ultrafinitism all TM's > can be replaced by lookup tables. Or looked at the other way > around, a sufficiently enormous lookup table is a computer. > Well, as Bruno points out, a lookup table can never be universal. What is true is that a lookup table can replace any program that halts, and the lookup table size is bounded by an exponential function of whatever bound you wish to apply to the number of steps the program must halt within. Within ultrafinitism, too, there cannot be lookup tables for all TMs because of this exponential relationship. > > But the interesting thing about Bruno's theory is that it proposes a > solution to the mind-body problem by making both of them > computations. Aside from the UD, this is not particularly radical. > If you had an intelligent/conscious AI within a virtual environment > then the consciousness of the AI would be relative to that > environment and both of them would be computations. Bruno proposes > that the relation can be expressed in terms of what the AI would > "believe", i.e. able to prove, about the environment. I find this > interesting aside from arguments trying to defeat some imaginary > "primitive physicalists". I'm not entire convinced they are imaginary. I used to think so, but John Clark is giving an awfully good impersonation of one. > The UD is interesting because it makes > Tegmarks mathematical-universe idea more specific, something you > might be able to draw inferences from. > Exactly. Regardless of truth, it is an interesting model that could well inform us about the truth. Provided it is tractable, of course, which so far it has tended not to be (John Clark's criticism). -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics [email protected] University of New South Wales http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
