On Fri, Oct 13, 2006 at 07:03:18AM -0000, [EMAIL PROTECTED] wrote: > > Also see my reply to Russell below: > > > >Russell Standish > > > >The Multiverse is defined as the set of consistent histories described > >by the Schroedinger equation. I make the identification that a quantum > >state is an observer moment, and the set of consistent quantum > >histories is the set of observer histories. As such all observer > >moments are in the Multiverse. > > > >But I appreciate this is not a widely held interpretation... > > > Indeed so. And there's a good reason why it isn't a widely held > interpretation, as J.barbour explained in 'The End Of Time'. In order > to define 'the Multiverse' in terms of QM one needs a *static* > wave-function solution for the entire universe (one which doesn't > change) , whereas conventional QM solutions to real world problems are > *dynamic* wave-function solutions (wave functions which evolve with > time). No one has yet succeeded in demonstrating a static > wave-function solution for the entire universe. >
I haven't read Barbour's book, but if that is what he is saying, he would be wrong. Consider a universe of a single electron living in a potential well V(x)=|x|^2, x\in R^3. There is a well defined solution \psi(t,x) = \sum_j <\psu_0|j><j| exp(-iE_j t) given the initial condition \psi_0. The function \psi: R x R^3 -> C is a static (time independent) mathematical object (I wrote it the mathematicians write to emphasize this point). Why wouldn't you identify this with the Multiverse of that electron? Now I am aware that several people (Hawking included I gather) have proposed various "wave functions of the universe", which tend to be solutions of the Wheeler de Witt equation, which is a time independent equation. However, I'm not so interested in following that literature. > See what I said above. If the *same* QM state could be associated with > *different* observer moments, then observer moments would not be > reducible to QM states and the set of consistent quantum histories > could not be said to be fully identified with the set of observer > histories. > If the same QM state is associated with different observer moments, you must be talking about some non-functionalist approach to consciousness. The QM state, by definition, contains all information that can be extracted from observation. Cheers -- *PS: A number of people ask me about the attachment to my email, which is of type "application/pgp-signature". Don't worry, it is not a virus. It is an electronic signature, that may be used to verify this email came from me if you have PGP or GPG installed. Otherwise, you may safely ignore this attachment. ---------------------------------------------------------------------------- A/Prof Russell Standish Phone 0425 253119 (mobile) Mathematics UNSW SYDNEY 2052 [EMAIL PROTECTED] Australia http://parallel.hpc.unsw.edu.au/rks International prefix +612, Interstate prefix 02 ---------------------------------------------------------------------------- --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---
