On Saturday, September 14, 2019 at 12:34:18 AM UTC-6, Jason wrote: > > > > On Friday, September 13, 2019, Alan Grayson <[email protected] > <javascript:>> 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. > > Each pocket universe may be finite in volume, but extends infinitely in > the time direction. >
Yes, time extends infinitely into the future, and so does space *unless the universe is closed.* But then he claims time and space flip with viewed externally to the bubble. But how does one get outside the bubble to observe it? Not possible AFAICT. AG > 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/ca6b23fc-0946-4bee-9170-ba6026e88360%40googlegroups.com.
