It's puzzling why Bruce and Clark affirm IR-reversible in principle in the context of the collapse model of the CI, when they should know that this is the source of the error. If the apparatus is treated quantum mechanically, we are left SOLELY with IR-reversible FAPP. But this is still an unproven, and likely unprovable result of decoherence theory. AG
On Sunday, August 14, 2022 at 11:40:13 AM UTC-6 Alan Grayson wrote: > I was referring to IRREVERSIBLIY IN PRINCIPLE, which is an artifact of the > collapse hypothesis of the CI. What remains, for sure, is IRREVERSIBILITY > FAPP. AG > > On Saturday, August 13, 2022 at 9:07:04 AM UTC-6 Alan Grayson wrote: > >> IRREVERSIBILITY is an artifact of the CI, where collapse occurs to an >> eigenstate of the observable being measured. But if the measuring apparatus >> is treated quantum mechanically, all processes associated with measurements >> are unitary and reversible. >> >> On Saturday, August 13, 2022 at 12:47:06 AM UTC-6 Alan Grayson wrote: >> >>> That's defining IRREVERSIBLE FAPP. OTOH, if X and Y produce Z at any >>> time, I don't see any way to reverse the process, so it's IRREVERSIBLE IN >>> PRINCIPLE. Do you agree? AG >>> >>> On Saturday, August 6, 2022 at 5:02:17 AM UTC-6 johnk...@gmail.com >>> wrote: >>> >>>> On Fri, Aug 5, 2022 at 6:47 PM Jesse Mazer <laser...@gmail.com> wrote: >>>> >>>> *> But when physicists say that a given system's dynamics are >>>>> "reversible" doesn't this generally involve an appeal to different >>>>> initial >>>>> boundary conditions?* >>>>> >>>> >>>> If at the time of the Big Bang the universe was it in an extremely low >>>> entropy state then even if the laws of physics were 100% deterministic >>>> and even if X and Y always produced Z and nothing except X and Y could >>>> produce Z the second law of thermodynamics would still insist that things >>>> are irreversible because there are an astronomical number to an >>>> astronomical power more ways for something to have high entropy than low >>>> entropy. >>>> >>>> John K Clark See what's on my new list at Extropolis >>>> <https://groups.google.com/g/extropolis> >>>> 2le >>>> >>>> >>>> -- 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/c0715c2e-4b00-4935-9229-c9a838c4f05dn%40googlegroups.com.
