On Wednesday, April 13, 2022 at 8:55:48 PM UTC+3 meeke...@gmail.com (Brent) wrote:

Decoherence has gone part way in solving the when/where/what basis > questions, but only part way. > As I wrote at the end of my first reply to your message, I share your concern about decoherence but I see the glass as half-full; that is, with a little more subtlety I hope that the matter can be formulated in clear terms. Surely collapse is easier to handle as a general concept (except, on the other hand, that it requires new dynamics). I forgot to mention that *my argument for deriving the Born Rule works with collapse, too* -- so it is an alternative to Gleason's theorem. Here I define colapse as an irreversible process, violating unitarity of course, and I keep it separate from randomisation. The latter means that each outcome is somehow randomised -- an assumption we can do without. *Collapse can also be described in a many-world formulation!* It differs from the no-collapse MWI only in being irreversible. My argument in outline is 1. assessment that MWI-with-collapse is workable; 2. therefore, outcomes of small enough measure can be neglected in practice; 3. now Everett's argument can proceed, concluding that the Born Rule is a practically safe assumption (to put it briefly). So I have replaced two assumptions of Gleason's theorem, randomisation and non-contextuality, by the assessment of workability only. If you don't feel comfortable yet with formulating collapse in a many-world setting, let us also assume randomisation (God plays dice), for the sake of the argument, in a single-world formulation. That is, we ASSUME the existence of probability; then the previous argument just guarantees that this probability follows the Born Rule. Of course I favour the first version of the argument, using the many-world formulation of collapse, to avoid the "God plays dice" nightmare. Thanks for the comments so far, because they stirred my thinking and motivated fresh ideas, some of which I hope will prove helpful and worth discussing, if and when they mature. George K. -- 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 on the web visit https://groups.google.com/d/msgid/everything-list/06930c0c-5537-4fb7-bf70-fd8c7d9859b0n%40googlegroups.com.