On Friday, February 14, 2025 at 6:16:15 PM UTC-7 Brent Meeker wrote:
On 2/14/2025 1:15 AM, Alan Grayson wrote: On Wednesday, February 12, 2025 at 11:09:34 PM UTC-7 Alan Grayson wrote: On Wednesday, February 12, 2025 at 2:26:02 PM UTC-7 Brent Meeker wrote: On 2/12/2025 11:04 AM, Alan Grayson wrote: On Wednesday, February 12, 2025 at 11:49:23 AM UTC-7 Quentin Anciaux wrote: AG, your reasoning is flawed because it assumes a contradiction where none exists. An infinite universe doesn’t have to "become" infinite—it can be infinite at all times, just evolving in density and scale factor. High temperature and density at the Big Bang don’t require finiteness; they describe local conditions, not global topology. Cosmological diagrams showing a "point" origin are simplifications based on the observable universe, not statements about the entire cosmos. The observable universe was smaller, but an infinite universe was never "shrinking" in the way you imply—just getting denser everywhere. But this contradicts the Cosmological Principle (which might be wrong). AG No it doesn't. Every finite subset of the infinite universe originated in a point (at least in the classical analysis). Brent Do you have a reference for this, like a theorem which proves the claim? TY, AG If there are two finite subsets of an infinite universe, is it conceivable that if one contains the other, can their union originate at the same point? AG Sure. Any subset of finite set is finite and so must originate from a point (in an FLRW model). Brent I was referring to the situation where one could keep containing the initial finite set, say the observable universe, and keep enlarging it by containing it in another finite set, but still having the SAME original point. Anyway, what I have real trouble conceptualizing is how a universe can emerge, or come into being, as infinite in spatial extent. It seems like a singularity of sorts, where there's an instantaneous expansion to infinity. 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 visit https://groups.google.com/d/msgid/everything-list/74a3b0ac-63e2-48d6-bc43-16e6283f9a7an%40googlegroups.com.
