On Mon, Jan 6, 2025 at 12:02 PM Russell Standish <li...@hpcoders.com.au> wrote:
> On Sun, Jan 05, 2025 at 04:47:00PM -0800, Brent Meeker wrote: > > > > What he fails to explain is how probabilities are realized in these > worlds. As > > Bruce pointed out, except for 50-50 cases the overwhelming number of > worlds > > find QM to be empirically falsified; so branch counting doesn't work. It > > appears that the Born rule adds another axiom; it's not just the > Schroedinger > > equation. > > > > Brent > > > > Bruce's argument is too coarse. He is assuming that all worlds have > equal representation in the original experimental preparation, whereas > the preparation process can clearly set things up such that there is > 90% up 10% down in the original sample, after which measurement is > performed. "Branch counting" can easily explain something like the > 90/10 Stern Gerlach case. > No, that does not work, even if you make the extreme assumption that measurement is a process of discrimination between already existing worlds (a point of view for which we have no evidence whatsoever.) In Everettian many worlds, every outcome is realized on every trial. So after one trial, there are two branches; after two trials, 4 branches; and so on; so that after N trials, there are 2^N branches. And this happens whatever the initial amplitudes are -- the Schrodinger equation does not act on the coefficients of each amplitude. It merely gives a branch for each existing amplitude (or eigenfunction in the superposition). So, as I said, you get the same 2^N sequences in every case. The majority of these will lead to a contradiction with the Born rule. (You get 50/50 probabilities whatever the initial superposition.) Where things fail is explaining something like the violation of Bell's > inequality. I originally thought I had an answer to that, but after > surface from the rabbit hole of maths, I realised I had to think again > :). > I think you have to understand that Bell's theorem depends only on the assumption of locality. In other words, the inequalities that are derived depend only on the assumption of locality: considerations such as realism and/or determinism play no role whatsoever. Since quantum mechanics violates the derived inequalities, it follows that QM is intrinsically non-local. And this is true for any interpretation of QM, including many-worlds. There is nothing really complicated about this. Bruce -- 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 everything-list+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAFxXSLTsAnU%3DoDf6k_L0MFzH1Sw0L-%3DQnVEqRqn%3D5GLbY6HKtw%40mail.gmail.com.
