On Sat, Sep 21, 2019 at 9:10 PM John Clark <johnkcl...@gmail.com> wrote:
> On Thu, Sep 19, 2019 at 12:07 PM Bruno Marchal <marc...@ulb.ac.be> wrote: > > >> *> Our decision are classical, so (even in the Everett quantum world) >> they do not "create new worlds”. I suspect Sean Carroll is quoted out of >> context, as indeed that is a mistake (a common one).* > > > If there is one theme running through Sean Carroll's new book it's that > nothing is classical and everything is Quantum Mechanical, and the > deterministic wavefunction of the Multiverse can be thought of as a > wavefunction of wavefunctions not of worlds because even the concept of a > world is just a human approximation. He suggests our current difficulties > in finding a theory that goes beyond General Relativity is that we're > trying to find something to stick onto it to make it Quantum Mechanical but > nature didn't start classical, it was Quantum Mechanical from day one, if > there was a day one and there may not have been. > Has Carroll forgotten about effective theories? Even QFT is just an "effective theory". We use classical approximations to quantum mechanics because they work -- not for ideological or philosophical reasons. 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 on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLTzmRFCT--0ShER042tLQm__FzEo6EbLWAOLMwa9MqCbA%40mail.gmail.com.
