On Sunday, January 19, 2020 at 10:07:47 PM UTC-7, Alan Grayson wrote: > > > > On Sunday, January 19, 2020 at 12:18:54 AM UTC-7, Brent wrote: >> >> >> >> On 1/18/2020 10:56 PM, Alan Grayson wrote: >> >> I don't claim anything except that GR has solutions for a cosmos in which >>> space is flat and, in that solution, space is infinite and empirically it >>> appears that space is flat. >>> >> >> *Measurements don't establish it's flat, as I previously argued. And, as >> you previously stated, the sign of k, the parameter in GR intimately >> associated with curvature, is folded into the initial conditions. But since >> the initial conditions are really unknown, or are speculative, you can >> assume initial conditions which satisfy your bias, in this case FLAT. AG * >> >> >> No. It's not an assumption. Empirically the universe appears flat, which >> (assuming the FLRW model) implies it was always flat. It is not a >> question of assuming an initial condition, it is inferring the initial >> condition from present measurements of k. >> >> Brent >> > > *If, say, you have a sphere with the diameter of a light year, how far > would its measured curvature deviate from zero? I'm suggesting that the > deviations from zero might be the same as for a flat universe. But I am > still stuck with an spatially infinite start, which most models incorporate > IIUC. AG * >
*Last sentence above: I mean that if it had a "start" with infinite spatial extent, that would seem to mean it did NOT have an infinite spatial extent just prior to the start. For me this seems like a singularity, an infinite physical process which occurs in zero time. If I were betting, I'd bet on a finite closed universe for any universe which "starts", not for the Multiverse. 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/a1b26979-c032-4b1b-9d7c-3990057cf5b0%40googlegroups.com.
