> On 28 Jan 2021, at 11:03 am, Bruce Kellett <bhkellet...@gmail.com> wrote: > > On Thu, Jan 28, 2021 at 10:44 AM smitra <smi...@zonnet.nl > <mailto:smi...@zonnet.nl>> wrote: > > FAPP, therefore not well defined at all. Sticking to FAPP you could > never have discovered Special Relativity, General Relativity, found the > correct way to resolve Maxwell's Demon paradox, etc. etc. > > FAPP is well-defined for all practical purposes. That is all that you require > for special and general relativity, statistical mechanics, and the rest of > physics. You cannot point me to any physical result that is not FAPP -- we > have only limited measurement precision, after all. And that is good enough > for real-world physics. >
Bruno’s point IIUC is that FAPP is OK for the physics you have now, but possibly not for the next physics. "Irreversible FAPP” means irreversible today. It’s true that there does come a point with decoherence where the state is irreversible, but that point is arbitrary and depends on the technology you have available. Proposals for testing MWI involve extending that point further and further. If you can reverse a quantum state that has evolved to macroscopic complexity, you can get interference and you’re on your way to showing that QM is indeed universal, and that MWI may be the best theory. FAPP is just giving up on testing, say, the Frauchiger-Renner experiment, which may prove to be tomorrow's equivalent of testing Bell’s theorem - not possible when the theorem was created, but possible later on. > Bruce > > -- > You received this message because you are subscribed to a topic in the Google > Groups "Everything List" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe > <https://groups.google.com/d/topic/everything-list/xsl8cSDT4M8/unsubscribe>. > To unsubscribe from this group and all its topics, send an email to > everything-list+unsubscr...@googlegroups.com > <mailto:everything-list+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAFxXSLSKqrr0KEg9ZHoOU1z58nsnP%2Bw%3DDFk04apjshzO3Gr7gg%40mail.gmail.com > > <https://groups.google.com/d/msgid/everything-list/CAFxXSLSKqrr0KEg9ZHoOU1z58nsnP%2Bw%3DDFk04apjshzO3Gr7gg%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- 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/E4D8AD83-F033-43B1-AE18-187475AF6B50%40gmail.com.
