On Friday, September 13, 2019, Alan Grayson <agrayson2...@gmail.com> 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 <agrays...@gmail.com> 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 <agrays...@gmail.com> 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. Each pocket universe may be finite in volume, but extends infinitely in the time direction. As Alan Guth explains, GR can warp things in the internal view of each pocket universe such that the time and space dimensions flip, the infinite time dimension within the pocket universe can give rise to the appearance of infinite space, and the finite space appears as finite time: https://youtu.be/rfeJhzPq3jQ 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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CA%2BBCJUiwU%2B1RgXkCKqjjp0xMZX6JXQgm0qMJceA55Vc5%2BY6KsQ%40mail.gmail.com.
