On Oct 31, 5:30 am, meekerdb <meeke...@verizon.net> wrote: > On 10/30/2011 5:13 PM, Nick Prince wrote: > > > > > On Oct 30, 8:56 pm, Russell Standish<li...@hpcoders.com.au> wrote: > > >> My point about the unitary evolution was that the clicking of the > >> Geiger counter is not a unitary process - and until you hear it, you > >> remain in > >> superposition. > > >> - Show quoted text - > > I thought that in the everett interpretation everything was unitary? > > > best wishes > > Nick > > Right. In Everett's interpretation Nick's consciousness exists in many > superpositions and > there must be some additional mechanism of consciousness that accounts for > the separation > of these conscious streams of experience. This would be the same mechanism > that collapses > the wave function in the Copenhagen interpretation - something like > decoherence except > that when the cross terms become sufficiently small they become exactly zero. > This would > be a "small" non-unitary step. But it requires that there be distinguished > variables in > which the density matrix becomes diagonal - the "pointer basis". > > Brent
Hi Brent Ok, after I'd posted the line above I thought again and wondered if my misunderstanding of Russell's answer was that he was indicating that a measurement made would cause the "click" which is essentally due to an hermitian non unitary operator. Yet in many accounts of the measurement procedure they follow my resoning that the apparatus doing the measuring, and the object being measured interact for some time via a unitary operation i.e. obey the SE. So I got confused. I understand that unitary operators are not observable operators yet they do describe the evolution of a state from one to another (as does the action of an observable operator) how do these accounts of the measurement process end up being consistent with each other? My understanding of QM must be lacking here. I read your answer but can't quite connect with it. Why must there be some additional mechanism of consciousness that accounts for the separation of these conscious streams of experience? In two branches of the multiverse can my consciousness not be at the end of the superposition that I put in the original post. exp(-iHt/hbar) (|s0>|a0>|Cons_0> = exp(-iHt/hbar) (c1|s1>|a0>|Cons_0> + c2|s2>|a0>|Cons_0>) (3) = (c1|s1>|a1>|Cons_1> + c2|s2>|a2>|Cons_2>) |s> = system, |a> = apparatus states |Cons_i> standing for conscious state of observer of the measurement. This accounts for 3p viewponts. I thought that 1p viewponts in any branch just change according to some U(t) such that U(t) |cons_i(0)> = |cons_i(t)>. Can you (anyone) help me to understand? Best wishes Nick -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to email@example.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.