Dear Jesse, A very good question, containing its own answer!
You wrote: > Why, out of all possible experiences compatible with my existence, do I only > observe the ones that don't violate the assumption that the laws of physics > work the same way in all places and at all times? Have you taken into account the idea that observers can communicate their finding to each other and that, maybe - just maybe - this plays into the wave function's behavior? David Deutsch has just posted a paper discussing a related subject (http://xxx.lanl.gov/abs/quant-ph/0401024). Let us take some time to read it and then pick this discussion back up. ;-) Kindest regards, Stephen ----- Original Message ----- From: "Jesse Mazer" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, January 08, 2004 1:17 AM Subject: Re: Is the universe computable? > Stephen Paul King wrote: > > > >Dear Jesse, > > > > Would it be sufficient to have some kind of "finite" or "approximate" > >measure even if it can not be taken to infinite limits (is degenerative?) > >in > >order to disallow for "white rabbits"? A very simple and very weak version > >of the anthropic principle works for me: Any observation by an observer > >must > >not contradict the existence of that observer. > > But there are plenty of observations that would not result in my > destruction, like seeing a talking white rabbit run by me, anxiously > checking its pocket watch. To pick a less fantastical example, it would also > not be incompatible with my existence to observe a completely wrong > distribution of photons hitting the screen in the double-slit experiment. > Why, out of all possible experiences compatible with my existence, do I only > observe the ones that don't violate the assumption that the laws of physics > work the same way in all places and at all times? > > > > > I disagree with David's claim that "The universe doesn't depend on the > >rock for its existence..." since the notion of quantum entanglement, even > >when considering decoherence, implies that the mere presense of a rock has > >contrapositive effects on the whole of the "universe". The various > >discussions of "null measurements" by Penrose and others given a good > >elaboration on this. > > I think you're talking about a different issue than David was. You're > talking about a rock that's a component of our physical universe, while I > think David was responding to Chalmers' question about whether random > thermal vibrations in a rock instantiate all possible computer simulations, > including a complete simulation of the entire universe (complete with all > the rocks inside it). > > > > > To me the computational question boils down to the question of how > >does > >Nature solve NP-Hard (or even NP-Complete) problems, such as those involved > >with "protein folding", in *what appears to be* polynomial time. > > What do you mean by "the" computational question? Are you addressing the > same question I was, namely how to decide whether some computer simulation > is instantiating a copy of some other program? If we imagine something like > a detailed physical simulation of some computer circuits running program X, > it seems intuitive that this simulation instantiates a copy of program X, > but Chalmers' paper suggests we don't have a general rule for deciding > whether one program is instantiating any other given program. And as I said, > this is relevant to the question of measure, and a measure on > observer-moments is probably key to solving the white rabbit problem. > > --Jesse > > _________________________________________________________________ > Get reliable dial-up Internet access now with our limited-time introductory > offer. http://join.msn.com/?page=dept/dialup > >