On Thu, Oct 13, 2011 at 05:20:11PM +0200, Bruno Marchal wrote: > > On 12 Oct 2011, at 23:48, Russell Standish wrote: > > >I certainly appreciate you don't use Bayes' theorem in your work, but > >don't understand why you say you cannot use it. > > I am not saying that we cannot use it in some context. I am not sure > we can use it to explain the physical laws in the comp frame, > because, it seems to me that it assume that we belong in a physical > universes among other possible one. But when we assume comp, we do > not belong to a universe, our bodies (at the subst level) "belong" > in infinitely many computations at once, and the appearance of the > universe results from the competition among those infinities of > computations. > It seems to me that in the comp theory Bayes's theorem can be used > to justify some geographical aspect, but not laws which have to e > independent of any observers. >
I don't see why Bayes' theorem assumes a physical universe. All it assumes is a prior probability distribution. Something like the universal prior of Solomonoff-Levin, or the distribution of observer moments within UD*. > >It is discussed in my book (page 83). The terminology (Occam > >catastrophe) is mine, but it is certainly possible that other people > >may have raised the issue by a different name. > > I will look at this again asap. I thought we discuss all this during > the ASSA/RSSA debate. > I don't recall this issue being discussed during that debate. There was some discussion on it after my book came out, but more about the conclusion that self-awareness is required for consciousness, which apparently people found counter-intuitive for some reason. > > > > >>Does the OCCAM catastrophe relies on Bayes? > > > >It is a consequence of the Occam's razor theorem, which in turn relies > >on the Solomonoff-Levin universal prior, and the working assumption of > >living in an ensemble. It doesn't rely on Bayes' > >theorem itself, but you can apply Bayes' theorem to the universal > >prior to get the only effective form of induction known. Li and > >Vitanyi has a good technical discussion of this, though not of the > >"catastrophe", as they don't assume an ontology. > > But this is closer to Hal Finney Universal Distribution theory, > based on ASSA. > Like in the doomsday argument, the reference base seems to me undefined. > I am not oppose to such an approach, I just don't understand how it > could work, and I prefer to avoid it. > I take observer dependent reference base. The beauty of something like COMP is one can show that all observers must generate equivalent reference bases - agreeing up to some additive constant independent of the complexity of what's being opbserved. > > > > >>What would it be with respect of UD*?. > > > >IFAICT, UD* should be equivalent to the all strings ensemble. > > I don't think so at all. This is missing the highly non trivial > structure on the set of all computations coming from the non trivial > notion of computations. Allmost all strings are random, but no > computations at all is random, except the result of the application > of the identity program on the arbitrary inputs when dovetailing on > inputs. But that is just a part of UD*. Most of UD* is not random at > all, and it has an extreme redundancy. There is the presence of deep > computations, self-referential entities, etc. > You may be right, but I think that needs to be demonstrated. If true, it should give rise to observable differences between my theory and yours, which would be an interesting and important result. BTW - I'm not convinced by Schmidhuber's speed prior work, which prima facie looks like an attempt in this direction. Are you? > >It wasn't a critique of your UDA and AUDA reasoning, (which I agree > >does not use probability, nor anthropic principle) but of your > >statement that Bayes' and the Anthropic Principle is inapplicable. > > Not in all context. The anthropic principle might been use for > deriving cosmological principles, but not the physical *laws*. > Why not? > Again if people have alternative, [to Theatetus] > and show to me how to translate them in arithmetic, I will interview > the LUMs accordingly :) > Sorry - I don't really have a good suggestion either. Epistemology is not my field :). -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au 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 post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
