> On 19 Jan 2020, at 10:54, Philip Thrift <[email protected]> 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.
I agree that an axiom of infinity is ontologically doubtful. Now, the universal numbers "already know” (too be short) that the axiom of infinity is phenomenologically necessary. They know that PA+infinity proves more than PA about the arithmetical reality. In fact the machine/numbers can prove their own incompleteness (conditionally to their consistency, though) and they know that if they want to explore the arithmetical reality, they will have to add new axioms all the time. The arithmetical realm is *essentially* undecidable. It is not just incomplete, it is incomplete-able.All effective theories about the arithmetical reality, or about the partial-computational reality, are incomplete. Bruno > > @philipthrift > > -- > 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] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/0a84eefd-80d2-4b95-bc43-a403d3302efa%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/0a84eefd-80d2-4b95-bc43-a403d3302efa%40googlegroups.com?utm_medium=email&utm_source=footer>. -- 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/A142BF56-BBF8-4117-8D8E-AE4A79D4A78D%40ulb.ac.be.
