On Sunday, January 19, 2020 at 12:58:59 AM 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. >> > > *This seems to modify what you wrote a few day ago. In any event, > "empirically" means "measurement", and one cannot measure the curvature as > exactly zero, which is what you need to empirically establish flatness. The > measurements are very close to zero, but not zero. AG* >
*All the FLRW model establishes is that IF it is flat, it was always flat. But the flatness or not, is determined by measurements, and they are ambiguous wrt flat or closed hyper-spherical. AG * > >> Brent >> > -- 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/02c8d50d-5146-4746-b99d-5435d3b8def7%40googlegroups.com.
