On Sat, Sep 14, 2019, 3:00 AM Alan Grayson <[email protected]> wrote:
> > > On Saturday, September 14, 2019 at 1:55:36 AM UTC-6, Alan Grayson wrote: >> >> >> >> On Saturday, September 14, 2019 at 12:34:18 AM UTC-6, Jason wrote: >>> >>> >>> >>> On Friday, September 13, 2019, Alan Grayson <[email protected]> wrote: >>> >>>> >>>> >>>> On Friday, September 13, 2019 at 4:42:00 PM UTC-6, Jason wrote: >>>>> >>>>> >>>>> >>>>> On Fri, Sep 13, 2019 at 8:25 AM Alan Grayson <[email protected]> >>>>> wrote: >>>>> >>>>>> >>>>>> >>>>>> On Friday, September 13, 2019 at 5:24:11 AM UTC-6, Bruno Marchal >>>>>> wrote: >>>>>>> >>>>>>> >>>>>>> On 13 Sep 2019, at 04:26, Alan Grayson <[email protected]> wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Thursday, September 12, 2019 at 11:01:54 AM UTC-6, Alan Grayson >>>>>>> wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Thursday, September 12, 2019 at 7:45:22 AM UTC-6, Lawrence >>>>>>>> Crowell wrote: >>>>>>>>> >>>>>>>>> On Thursday, September 12, 2019 at 4:20:46 AM UTC-5, Philip Thrift >>>>>>>>> wrote: >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> On Wednesday, September 11, 2019 at 11:45:41 PM UTC-5, Alan >>>>>>>>>> Grayson wrote: >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> https://www.wired.com/story/sean-carroll-thinks-we-all-exist-on-multiple-worlds/ >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Many Worlds is where people go to escape from one world of >>>>>>>>>> quantum-stochastic processes. They are like vampires, but instead of >>>>>>>>>> running away from sunbeams, are running away from probabilities. >>>>>>>>>> >>>>>>>>>> @philipthrift >>>>>>>>>> >>>>>>>>> >>>>>>>>> This assessment is not entirely fair. Carroll and Sebens have a >>>>>>>>> paper on how supposedly the Born rule can be derived from MWI I have >>>>>>>>> yet >>>>>>>>> to read their paper, but given the newsiness of this I might get to >>>>>>>>> it. One >>>>>>>>> advantage that MWI does have is that it splits the world as a sort of >>>>>>>>> quantum frame dragging that is nonlocal. This nonlocal property might >>>>>>>>> be >>>>>>>>> useful for working with quantum gravity, >>>>>>>>> >>>>>>>>> I worked a proof of a theorem, which may not be complete >>>>>>>>> unfortunately, where the two sets of quantum interpretations that >>>>>>>>> are ψ-epistemic and those that are ψ-ontological are not decidable. >>>>>>>>> There >>>>>>>>> is no decision procedure which can prove QM holds either way. The >>>>>>>>> proof is >>>>>>>>> set with nonlocal hidden variables over the projective rays of the >>>>>>>>> state >>>>>>>>> space. In effect there is an uncertainty in whether the hidden >>>>>>>>> variables >>>>>>>>> localize extant quantities, say with ψ-ontology, or whether this >>>>>>>>> localization is the generation of information in a local context from >>>>>>>>> quantum nonlocality that is not extant, such as with >>>>>>>>> ψ-epistemology. Quantum interprertations are then auxiliary >>>>>>>>> physical axioms or postulates. MWI and within the framework of what >>>>>>>>> Carrol >>>>>>>>> and Sebens has done this is a ψ-ontology, and this defines the >>>>>>>>> Born rule. If I am right the degree of ψ-epistemontic nature is >>>>>>>>> mixed. So the intriguing question we can address is the nature of the >>>>>>>>> Born >>>>>>>>> rule and its tie into the auxiliary postulates of quantum >>>>>>>>> interpretations. >>>>>>>>> Can a similar demonstration be made for the Born rule within QuBism, >>>>>>>>> which >>>>>>>>> is what might be called the dialectic opposite of MWI? >>>>>>>>> >>>>>>>>> To take MWI as something literal, as opposed to maybe a working >>>>>>>>> system to understand QM foundations, is maybe taking things too far. >>>>>>>>> However, it is a part of some open questions concerning the >>>>>>>>> fundamentals of >>>>>>>>> QM. If MWI, and more generally postulates of quantum >>>>>>>>> interpretations, are connected to the Born rule it makes for some >>>>>>>>> interesting things to think about. >>>>>>>>> >>>>>>>>> LC >>>>>>>>> >>>>>>>> >>>>>>>> If you read the link, it's pretty obvious that Carroll believes the >>>>>>>> many worlds of the MWI, literally exist. AG >>>>>>>> >>>>>>> >>>>>>> Carroll also believes that IF the universe is infinite, then there >>>>>>> must exist exact copies of universes and ourselves. This is frequently >>>>>>> claimed by the MWI true believers, but never, AFAICT, proven, or even >>>>>>> plausibly argued. >>>>>>> >>>>>>> >>>>>>> The idea comes from Tegmark, and I agree with you, it necessitate >>>>>>> more than an infinite universe. It requires also some assumption of >>>>>>> homogeneity. >>>>>>> >>>>>> >>>>>> Our universe is, on a large scale, homogeneous. But it can't be >>>>>> infinite since it has only been expanding for finite time, 13.8 BY. I >>>>>> had a >>>>>> discussion with Brent about this some time ago, and he claimed finite in >>>>>> time doesn't preclude infinite in space. I strongly disagree. Perhaps I >>>>>> am >>>>>> missing something. Wouldn't be the first time. AG >>>>>> >>>>> >>>>> I think what you may be missing is that in popular (but misleading) >>>>> accounts of the BB they often say everything originated from a point, >>>>> rather than everywhere at once. To say "everything came from a point" is >>>>> at best only valid for describing the observable universe (or any finite >>>>> portion of the universe) but is invalid to extrapolate it to the whole >>>>> universe, which may be spatially infinite. >>>>> >>>> >>>> I am not assuming our universe began from a mathematical point, but I >>>> do assume that 13.8 BYA it was very very small, the observable and >>>> unobservable parts. >>>> >>> >>> Why do you assume this? Most cosmologists make no such assumption. >>> Under the concordance (standard assumed) model of cosmology, space is >>> infinite. >>> >>> >>>> >>>> >>>> >>>> I don't think there is an implied disconnect between our measurements >>>> of the CMBR and what an observer would measure in parts we have no access >>>> to. It was everywhere hot and dense, and very very small. >>>> >>> >>> There's no observational motivation for the universe being very very >>> small at the beginning. It could have been small, large or infinite, for >>> all we know. >>> >>> >>>> If it were infinite at that time, its temperature would have been near >>>> absolute zero. AG >>>> >>> >>> I think you're working under the assumption that some finite amount of >>> energy was injected into space at one particular point. This is not what >>> the big bang theory says, rather all space (everywhere there was space), >>> was equally hot and dense. >>> >>> Inflation modifies the picture a bit where the vacuum of space expands >>> rapidly due to its high energy density (which suggests a negative >>> pressure). Under the equations of GR, such a state would expand itself >>> exponentially. Eventually parts of this vacuum decay to a lower energy >>> density, and this dump of energy into space gives us the early hot stage of >>> the big bang. >>> >>> We don't know how big this initial inflating space was, but if inflation >>> is right, most of the universe is still experiencing exponential growth. >>> >> > We don't know why inflation started and what stopped it, if it stopped. AG > We don't know where the initial vacuum state came from, but with certain assumptions we can say why it stops in some places and continues in others.tge reasons are inherently quantum in nature, like the decay of a radioactive element. Inflation may bring it's own questions, but it solves at least four problems: Why space is so flat Why the universe is still expanding Where the heat and energy came from Why we see no magnetic monopoles It might also explain some fine tuning mysteries, if other vacuum states are possible, as they are under string theory. Finally, there's observational support for inflation based on the latest measurements of the CMB by the Planck satellite. Jason -- 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/CA%2BBCJUhPbm4kj2N6S-zwtSGSP4F0EZdPZwneDci6%2BsWfjhjg3w%40mail.gmail.com.
