> On 20 Aug 2018, at 19:59, Brent Meeker <[email protected]> wrote: > > > > On 8/20/2018 2:06 AM, Bruno Marchal wrote: >>> On 19 Aug 2018, at 21:36, Brent Meeker <[email protected]> wrote: >>> >>> >>> >>> On 8/19/2018 3:09 AM, Bruno Marchal wrote: >>>>> On 17 Aug 2018, at 22:59, Brent Meeker <[email protected]> wrote: >>>>> >>>>> >>>>> >>>>> On 8/17/2018 7:37 AM, Bruno Marchal wrote: >>>>>>> Of course, but that does not justify the idea that all branches >>>>>>> pre-exist. >>>>>> But that is not exactly what I am saying. I am saying that some >>>>>> superposition can be interpreted as different superposition. When Alice >>>>>> choose her spin direction, she will chose a partition of the multiverse, >>>>>> which is a sort of multi-multiverse. Without this, not only we have FTL, >>>>>> but we get super-determinism. Alice is no more choosing anything. >>>>> But already with no-collapse multiverse you have super determinism. >>>> ? >>>> >>>> >>>> >>>>> The only question is where different branches of possibility diverge. >>>>> Alice's choosing is, in the usual case, a deterministic choice, not one >>>>> that produces or identifies her with a different branch than the one >>>>> before her choice. It just muddles the argument to introduce the >>>>> measurement directions as different possibilities. >>>> Yet, if she has a “real ability to chose”, that will determine the type of >>>> branch she can found herself in. If not, the singlet state cannot be >>>> rotationally invariant. The singlet state gives an infinity of >>>> superposition possibles. We forget this by assuming that ud is supposed to >>>> du, but u’d is superposed with d’u’ too. >>> But Alice and the detector are not in a singlet state and when you combine >>> them in a product with the singlet state the result is no long rotationally >>> invariant. >> The rotational invariance of the singlet state has not been broken, and in >> principle Alice can get back to it by quantum memory erasure, unless >> collapse. > > Yes, by erasing her interaction with it. But the interaction term depends > on her choice of detector orientation, so the symmetry is broken by the > interaction even before there is decoherence...which is why it is possible to > erase it.
Interaction = entanglement =decoherence, and it seems irreversible when it involves to big numbers to memorise and “tracks”. I would say, in Everett. (Not sure for mechanism here, it is premature to ask). Bruno > > Brent > >> >> Bruno >> >> >> >>> Brent >>> >>>> Bruno >>>> >>>> >>>> >>>> >>>> >>>> >>>>> Brent >>>>> >>>>> -- >>>>> 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 [email protected]. >>>>> To post to this group, send email to [email protected]. >>>>> Visit this group at https://groups.google.com/group/everything-list. >>>>> For more options, visit https://groups.google.com/d/optout. >>> -- >>> 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 [email protected]. >>> To post to this group, send email to [email protected]. >>> Visit this group at https://groups.google.com/group/everything-list. >>> For more options, visit https://groups.google.com/d/optout. > > -- > 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 [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
