On Sunday, September 15, 2024 at 6:24:40 AM UTC-6 John Clark wrote:
On Sun, Sep 15, 2024 at 3:26 AM Alan Grayson <[email protected]> wrote: > *I prefer approximately spherical compared to flat because as we go backward in time, we can enclose the universe in a sphere, implying it is finite in spatial extent (not infinite).* *There is no such implication. If the universe is a 3-sphere then it could be finite or infinite. * *The sphere I am referring to is finite in spatial extent. AG * *A 3-sphere is a compact, connected, 3-dimensional manifold without boundary embedded in 4-space, any loop on a 3-sphere can be continuously shrunk to a point without leaving the 3-sphere.* * > It then occurred to me that the Unobservable universe was plausibly created during Inflation, * *NO. The rate of expansion during inflation was mind blowingly gargantuan, but it was finite. If the universe was infinite before inflation then it was infinite after it, and if it was finite before inflation then it was finite after it. * *Why the "NO"? I completely agree with your comment and never intended otherwise. I am saying that if the universe was finite when Inflation began, it might have created an Unobservable but FINITE region as a result of Inflation. And then, if we run the clock backward, this FINITE, presently Unobservable region, will come back into view. AG * *> to Alan Guth. I asked him, when he assumes the universe was around the size of a proton when Inflation began, was he referring only to the Observable universe,* *I know for a fact Guth was referring to the observable universe because he's a good enough physicist to know that a proton and the observable universe have one thing in common, both of them are finite in size. And no physical process can turn a finite thing into an infinite thing.* *Of course; I never stated otherwise! Note that a physicist holding a prestigious position at a US university disagreed that the universe might be finite before Inflation began, implying that Guth might NOT have considered the very early universe as finite. I asked Guth about this very issue. Hopefully, we'll get an answer. AG * * > or both hypothetic parts, Observable and Unobservable. * *If the universe has any curvature at the largest possible scale it is unobservable, and if you insist that postulating that something you cannot observe and will never be able to observe nevertheless exists is unscientific, then you would have to conclude that the pope was right and Galileo was wrong because the Earth really is the center of the universe. Do you really want to insist on that? * *I tend to believe the universe is positively curved, but beyond our ability to distinguish curved from flat. I wasn't insisting on anything. I was just wondering what Guth assumed, finiteness or not, when Inflation began, given the physicist's critique of my conjecture. You seem to have an obsession in proving I am mistaken, when you obviously have no clue of my reasoning in this matter. I am just trying to determine Guth's intention, not claiming to be able to do the impossible, such as measuring something in the unobservable universe. AG* John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> uss -- 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/e7d8812f-93d1-4d63-bc98-0eb69aecd8aan%40googlegroups.com.
