On Sun, Mar 09, 2014 at 06:15:07AM -0700, Edgar L. Owen wrote: > Russell, > > Yes, but that is crazy because it assumes all theories are equally valid > with which I disagree. Science selects theories based on which best explain > the observable universe. Therefore it is reasonable to assume that theories > DO reflect actual reality. They are not just made up by humans willy > nilly.... > > I would be surprised if Brent, a physicist, disagrees with that but I'll > let him speak for himself. > > Edgar >
Actually, both Brent and Liz made comments here which I broadly agree with, as well as pointing out David Deutsch's position, which I do find myself in disagreement, for much the same reasons they mentioned. I would describe myself as an agnostic realist, not an a-realist. There may very well be some external reality propping everything up, but if COMP is true, and more importantly, if our observed reality is some random selection from the space of all possible bits strings compatible with our existence (eg we are facing UD*), then the properties of that external reality are fundamentally unknowable. It is about as useful a hypothesis as a deist God who doesn't interfere in the running of the universe. One of David's strongest arguments in favour of a genuine external reality is the fact that the physical universe seems incapable of computing things that Turing machines are incapable of. His counter example is the Infinity Hotel universe, based on the popular "Infinity Hotel" story used to introduce Cantor's paradise to maths students. The Infinity Hotel is capable of computing things which are impossible in our universe, or in any Turning machine, for that matter. It is an example of a hypercomputer. This is not a problem with COMP, which axiomatically supposes the conventional Turing model of computation is all that exists. But it may be an issue for my somewhat more general "Nothing" model of all bitstrings, as a priori, there is no restriction of computational models. It remains an open problem to show whether the "Nothing" naturally implies the Turing model, or the converse, that hypercomputers are indeed possible in that idea (in which case my thesis would be refuted, and David would essentially be right). But my point remains, at this point in time, intrasubjective consistency is not sufficient to demonstrate the existence of an external reality independent of the process of observation, contra Edgar's claim. -- ---------------------------------------------------------------------------- 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.
