On Sat, Sep 21, 2019 at 9:10 PM John Clark <[email protected]> wrote:
> On Thu, Sep 19, 2019 at 12:07 PM Bruno Marchal <[email protected]> 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAFxXSLTzmRFCT--0ShER042tLQm__FzEo6EbLWAOLMwa9MqCbA%40mail.gmail.com.
