We are living in consciousness. On Wednesday, 19 March 2025 at 16:56:19 UTC+2 Alan Grayson wrote:
> On Wednesday, March 19, 2025 at 8:22:35 AM UTC-6 Quentin Anciaux wrote: > > Yes, if we extrapolate the standard Big Bang model backward in time, the > density increases everywhere without bound as T approaches zero. In an > infinite universe, this means every region, even in the unobservable part, > reaches arbitrarily high density simultaneously. This is why the Big Bang > is often described as a singularity in time, not in space—it’s not a > localized point, but rather a state where all of space was at infinitely > high density at the same time. > > > That's what I recall, but it seems ridiculous so I didn't want to state > it. AG > > However, in modern cosmology, the singularity at T=0 is generally > considered an indication that our current physical theories break down > rather than an actual point of "infinite density everywhere." Quantum > gravity effects (which we don’t yet fully understand) would likely smooth > out this singularity, preventing true infinite density. Inflationary models > also suggest that what we call the "Big Bang" may not be a singular > beginning but instead a transition from a pre-existing state (such as a > quantum fluctuation, an eternal inflation scenario, or a bounce from a > prior contracting phase). > > So, while classical general relativity predicts a singularity of infinite > density everywhere as T -> 0, most physicists suspect this is a limitation > of the theory, and quantum gravity will provide a more complete picture. > > > I personally doubt there will ever be a quantum theory of gravity. A > repulsive fifth force seems like a simpler possible solution. Is there any > substantive objection to this conjecture? AG > > > Quentin > > All those moments will be lost in time, like tears in rain. (Roy > Batty/Rutger Hauer) > Le mer. 19 mars 2025, 15:13, Alan Grayson <[email protected]> a écrit : > > > > 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 > > -- 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/24997937-7495-4e18-852c-965e910843a2n%40googlegroups.com.
