On Wednesday, March 19, 2025 at 6:44:47 AM UTC-6 Quentin Anciaux wrote:
Well guess I have to use my fingers for you... you know any decent email client has a search function: AG, your statement "density can't diverge unless volume goes to zero" assumes a finite volume, which doesn’t apply in an infinite universe. In an infinite universe, density can increase indefinitely everywhere without requiring a total volume to shrink. Brent is correct that the observable universe (the region we can see) shrinks as we go back in time, but that doesn’t mean the entire universe (including the unobservable part) does the same. The observable universe is just a region within an infinite space, and as we go back in time, the light cone that defines what we can observe gets smaller. If the entire universe is infinite, its total volume remains infinite at all times—but its density can still increase without bound. There’s no contradiction. If average galactic distances decrease as we go back in time, the density increases locally everywhere without limit in the unobservable region. Won't this be a singularity of infinite density everywhere as T decreases to zero? AG Quentin This is *one* of numerous answers given. All those moments will be lost in time, like tears in rain. (Roy Batty/Rutger Hauer) Le mer. 19 mars 2025, 12:56, Alan Grayson <[email protected]> a écrit : On Wednesday, March 19, 2025 at 5:40:48 AM UTC-6 John Clark wrote: On Wed, Mar 19, 2025 at 4:30 AM Alan Grayson <[email protected]> wrote: *> If the universe is infinite in spatial extent, and we run the clock backward, is all the mass/energy of the observable region confined to a tiny or zero volume?* *The short answer is nobody knows what will happen if you run the clock back to zero, and the mystery remains regardless of if the universe is finite or infinite. Nobody knows what will happen when things get super small because our two best physical theories, Quantum Mechanics and General Relativity, disagree with each other. Most believe that something will prevent a zero volume from ever occurring, but nobody knows what that "something" is. * *John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* Maybe it's a 5th force. What I'd like to know is this; assuming an infinite spatial universe and that it gets very very small as we run the clock backward, the observable regions shrinks, but what happens to the unobservable region? Quentin claimed to have an answer, but I can't recall what it was. AG 23x -- 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/ae72c1a9-1763-4a43-b91f-f2cc67150a35n%40googlegroups.com <https://groups.google.com/d/msgid/everything-list/ae72c1a9-1763-4a43-b91f-f2cc67150a35n%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 visit https://groups.google.com/d/msgid/everything-list/d3770fa7-6df0-42d7-a3ce-a48f01951391n%40googlegroups.com.
