On Friday, October 11, 2019 at 9:32:04 AM UTC-5, John Clark wrote: > > On Mon, Oct 7, 2019 at 2:49 PM Philip Thrift <[email protected] > <javascript:>> wrote: > > >> https://aeon.co/essays/post-empirical-science-is-an-oxymoron-and-it-is-dangerous >> > > *> the so-called Many-Worlds interpretation of quantum mechanics, there >> are universes containing our parallel selves, identical to us but for their >> different experiences of quantum physics. These theories are attractive to >> some few theoretical physicists and philosophers, but there is absolutely >> no empirical evidence for them.* > > > I would maintain that the 2 slit experiment is, not proof, but evidence > that Many Worlds is right because if it is right then the odd results from > that experiment is exactly what you should expect to see; and if it's not > right and those other worlds do not exist then, to be compatible with > observation, new physics must be postulated, such as in > Ghirardi-Rimini–Weber theory (GRW). GRW modifies the Schrodinger equation > so it's no longer completely deterministic (Einstein would not have liked > that) and as a result on very rare random occasions, about once every > hundred million years, the wave function of a particle spontaneously > collapses for no reason at all. Despite claims, made by those who haven't > read it, that Carroll's book doesn't talk about alternatives to Many Worlds > he goes into much more detail about GRW than I have here, but please note > that the bottom line fact is *there is absolutely no empirical evidence > that GRW theory is true*. So is GRW also a danger to science? > > John K Clark >
I did a search of his book [ https://books.google.com/books?id=f16IDwAAQBAJ ] and though he does write about *Feynman diagrams* I don't see anything about *path integrals*. That would be a curious omission. https://arxiv.org/abs/1808.04178 Path integrals, spontaneous localisation, and the classical limit Bhavya Bhatt <https://arxiv.org/search/quant-ph?searchtype=author&query=Bhatt%2C+B>, Manish Ram Chander <https://arxiv.org/search/quant-ph?searchtype=author&query=Chander%2C+M+R>, Raj Patil <https://arxiv.org/search/quant-ph?searchtype=author&query=Patil%2C+R> , Ruchira Mishra <https://arxiv.org/search/quant-ph?searchtype=author&query=Mishra%2C+R>, Shlok Nahar <https://arxiv.org/search/quant-ph?searchtype=author&query=Nahar%2C+S> , Tejinder P. Singh <https://arxiv.org/search/quant-ph?searchtype=author&query=Singh%2C+T+P> (Submitted on 13 Aug 2018 (v1 <https://arxiv.org/abs/1808.04178v1>), last revised 31 Jan 2019 (this version, v3)) We recall that in order to obtain the classical limit of quantum mechanics one needs to take the ℏ→0 limit. In addition, one also needs an explanation for the absence of macroscopic quantum superposition of position states. One possible explanation for the latter is the Ghirardi-Rimini-Weber (GRW) model of spontaneous localisation. Here we describe how spontaneous localisation modifies the path integral formulation of density matrix evolution in quantum mechanics. (Such a formulation has been derived earlier by Pearle and Soucek; we provide two new derivations of their result). We then show how the von Neumann equation and the Liouville equation for the density matrix arise in the quantum and classical limit, respectively, from the GRW path integral. Thus we provide a rigorous demonstration of the quantum to classical transition. @philipthrift -- 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/83850285-686d-4f82-9904-f882294781f2%40googlegroups.com.
