On Saturday, September 14, 2019 at 5:31:12 AM UTC-6, Lawrence Crowell wrote: > > On Saturday, September 14, 2019 at 6:02:13 AM UTC-5, Alan Grayson wrote: >> >> >> >> On Saturday, September 14, 2019 at 3:56:42 AM UTC-6, Lawrence Crowell >> wrote: >>> >>> On Friday, September 13, 2019 at 10:22:38 PM UTC-5, Alan Grayson wrote: >>>> >>>> >>>> >>>> On Friday, September 13, 2019 at 4:08:23 PM UTC-6, John Clark wrote: >>>>> >>>>> On Thu, Sep 12, 2019 at 10:26 PM Alan Grayson <[email protected]> >>>>> wrote: >>>>> >>>>> >>>>>> *> 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. What's the argument for such a claim?* >>>>>> >>>>> >>>>> Of course it's been proven! It's simple math, there are only a finite >>>>> number of ways the atoms in your body, or even the entire OBSERVABLE >>>>> universe, can be arranged so obviously if the entire universe is infinite >>>>> then there is going to have to be copies, an infinite number of them in >>>>> fact. Max Tegmark has even calculated how far you'd have to go to see >>>>> such a thing. >>>>> >>>> >>>> What I think you're missing (and Tegmark) is the possibility of >>>> UNcountable universes. In such case, one could imagine new universes >>>> coming >>>> into existence forever and ever, without any repeats. Think of the number >>>> of points between 0 and 1 on the real line, each point associated with a >>>> different universe. AG >>>> >>>>> >>>>> Your closest identical copy is 10^12 light years away. About 10^76 >>>>> light years away there is a sphere of radius 100 light-years identical to >>>>> the one centered here, so everything we see here during the next century >>>>> will be identical to those of our counterparts over there. And 10^102 >>>>> light >>>>> years away the is a exact copy of our entire observable universe. And all >>>>> this is true regardless of if the Many Worlds Interpretation of Quantum >>>>> Mechanics is correct or not, it only depends on the universe being >>>>> spatially infinite. >>>>> >>>> >>>> But our universe is NOT spatially infinite if its been expanding for >>>> finite time, starting very small, as can be inferred from the temperature >>>> of the CMBR. AG >>>> >>> >>> This is wrong. The CMB is at a distance of 46 billion light years while >>> it was also generated 13.8 billion years ago. The more distant things are >>> the more it is frame dragged by the accelerated expansion, in a sense a >>> "soft inflationary" expansion. If this were not the case the CMB would have >>> markedly different characteristics. >>> >>> LC >>> >> >> Doesn't the high temperature and density at BB +380,000 years imply the >> universe was small at that time? AG >> > > It implies that matter and radiation had a higher density. Whether the > space of this cosmology was smaller is problematic. If the space is R^3 > without bounds it makes no sense to say it was smaller. The same if the > space is the Poincare dodecahedron space. > > LC >
To reiterate: I've never read a description of inflation where the universe is described as very large spatially when it initiates. It's always claimed inflation begins a few Planck durations (10^-43 seconds) after the BB, at which time the spatial diameter is many orders of magnitudes smaller than the diameter of a proton. Inflation then expands the universe to the diameter of the Earth or the Solar System before terminating, all this occuring within the first second after the BB. The idea behind inflation is to preserve the original homogeneity of a universe presumed be very small, and therefore causally connected.This entire model breaks down if one insists on a large universe immediately after the BB. As I understand it, present models have the expansion continuing until present, and even at 380,000 it's still relatively small but homogeneous. AG -- 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/1b45f319-4fa1-4614-a455-4fc4aeae747a%40googlegroups.com.
