On Sunday, January 19, 2020 at 2:54:49 AM UTC-7, Philip Thrift wrote: > > > > On Saturday, January 18, 2020 at 6:04:53 PM UTC-6, Alan Grayson wrote: >> >> >> >> On Saturday, January 18, 2020 at 2:55:16 PM UTC-7, Brent wrote: >>> >>> >>> >>> On 1/18/2020 1:29 AM, Alan Grayson wrote: >>> >>> *the infinite spatial extent must have occurred instantaneously, at the >>> BB.* >>> >>> >>> It doesn't have to "occur". If the universe is infinite then it didn't >>> become infinite, it was always (in some timeless way) infinite. The >>> equations of cosmology are just for a scale factor. We estimate the >>> parameters from observation and project back to a beginning. So there's >>> really no sense in projecting back to zero scale factor...there the size of >>> a flat universe according the equations is infinity*zero. Hopefully a >>> quantum theory of gravity will replace that oo*0 with something more >>> sensible. >>> >>> Brent >>> >> >> What do "infinity*zero" and "oo*0" mean? I see your point. My problem is >> that we seem to have a universe with a BEGINNING, called the BB, and I find >> it virtually impossible to imagine it starting with an infinite spatial >> extent. How could "nothing" become infinite in any parameter, suddenly, or >> due to finite processes? What I can imagine is it emerging from something >> flat and eternal, having an infinite past. AG >> > > > > > Any theory (of physics/cosmology) that *asserts the existence of infinite > anythings* as an "axiom" or starting point has no basis of any support by > empirical data. (That I am aware of.) > > So it seems useless to even talk about them. > > @philipthrift >
*Hypothetically, one could measure the curvature of spacetime and conclude it implies flatness. This wouldn't be an axiom, but an inference from data. As I have previously stated, I don't think the measured curvature unambiguously implies flatness. 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/676e6fa6-1df8-4cd3-9b1d-7e20b0683ace%40googlegroups.com.
