On Tuesday, June 19, 2018 at 12:53:29 AM UTC, John Clark wrote: > > > On Mon, Jun 18, 2018 at 7:54 PM, <[email protected] <javascript:>> > wrote: > > *> If you accept Inflation, the universe is many orders of magnitude >> larger than what we can observe. How much larger depends on the model of >> Inflation one applies. However, AFAIK, there's no persuasive theory that >> claims its extent in space or time is INFINITE.* > > > During inflation the expansion of the universe was exponential which means > it had a fixed doubling time, in this case every 10^-37 seconds the > diameter of the universe doubled. In 10^-35 seconds it doubled a hundred > times and it probably continued doubling for much longer than 10^-35 > seconds.But why did it ever end? > > According to Andrei Linde inflation never did end. Alan Guth, the inventor > of inflation, postulated an inflation field that decayed away in a process > somewhat analogous to radioactive half life, and after the decay the > universe expanded at a much much much more leisurely pace. But then Linde > proved that for Guth's idea to work the inflation field had to expand > faster than it decayed, Linde called it "Eternal Inflation". Linde showed > that for every volume in which the inflation field decays away 2 other > volumes don't decay. So one universe becomes 3, the field decays in one > universe but not in the other 2, then both of those two universes splits in > 3 again and the inflation field decays away in two of them but doesn't > decay in the other 4. And it goes on like this forever creating a > multiverse. > > *>I haven't delved deeply into this issue. I tend to the position that >> the universe MIGHT be infinite in space and time, but NOT our local bubble, >> which I believe is finite. AG* > > > Our observable universe is not only finite its getting smaller due to the > accelerating expansion of space. In a trillion years or so it will consist > of Milkdromeda (the combined Milky Way and Andromeda galaxy) and that's it > because everything else will be moving away from us faster than light and > thus be unobservable > . >
*When I referred to "our local bubble", I meant our entire universe, not just the observable region which is shrinking. Even with Eternal Inflation, our local bubble remains finite if it began at some TIME in the past; that is, if its age if finite. For it to be infinite, I would think it couldn't have a beginning. AG * > > John K Clark > > > > -- 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
