Wei Dai wrote: > On Tue, Jun 09, 1998 at 04:13:22AM +0000, Nick Bostrom wrote: > > Only if you believe in the many-worlds interpretation. A believer in > > the MWI will have to add the idea of a measure, and say:"I will > > observe X" with amplitude psi(x), and "I will observer Y" with > > amplitude psi(y). This can then be translated into probabilities by > > squaring the amplitude. > > I'm not sure what you mean. How does it differ from what I suggested?
I'm not sure it does, except that it is a clarification of an earlier suggestion I made that you objected to: > On Fri, May 29, 1998 at 04:03:00AM +0000, Nick Bostrom wrote: > > It seems we can interpret "I will observe X" as meaning: "There is > > a future brain-state B2, similar in certain respects to the > > brain-state B1 which instanciates this present cognition C1, such > > that B2 instanciates C2, and C2 includes an observation of X.". > > That is not going to give you nice results. For example if there is > no wavefunction collapse, all possible brain-states exist in the > future and "I will observe X" would have probability 1 for all X > under your interpretation. Do you think that the interpretation I mention works for non-quantum situations? (Instead of saying "...similar in certain respects...", I would now say "...standing in a certain relation R to...", since in some theories of personal identity R will involve more than similarity.) If I am copied, then, depending on the details of the execution and on R, there might either be one or two brains belonging to my future self. The two brains might even have different perceptions. If they both belong to my future self, I should have to say that I will have multiple perceptions. Now, if we want to combine this with the many-worlds interpretation, we have to take into account that both the future brains may be in superpositions, i.e. they might be instanciated in many different real worlds. Will all these different brains, existing in different worlds, belong to the same person? -- That depends on how different these brains are from one another and on R. So whether "I will observer X" has probability 1 in my interpretation depends on what specific case you have in mind and on your theory of personal identity. _____________________________________________________ Nicholas Bostrom Department of Philosophy, Logic and Scientific Method London School of Economics [EMAIL PROTECTED] http://www.hedweb.com/nickb
