All those moments will be lost in time, like tears in rain. (Roy Batty/Rutger Hauer)
Le mer. 19 mars 2025, 10:19, Alan Grayson <[email protected]> a écrit : > > > On Wednesday, March 19, 2025 at 2:39:57 AM UTC-6 Quentin Anciaux wrote: > > > > All those moments will be lost in time, like tears in rain. (Roy > Batty/Rutger Hauer) > > Le mer. 19 mars 2025, 09:30, Alan Grayson <[email protected]> a écrit : > > > > On Tuesday, March 18, 2025 at 11:52:42 PM UTC-6 Quentin Anciaux wrote: > > AG, > > No, I’m not asserting that the universe is spatially finite. The standard > ΛCDM model allows for an infinite spatial extent while still experiencing > expansion. The observable universe is finite due to the speed of light and > the age of the universe, but beyond that, space could extend infinitely > while still expanding. Expansion refers to the metric stretching of space, > not necessarily implying a finite boundary. Already discussed. > > Some photons emitted in the unobservable region will never reach us > because their source galaxies are receding too fast, while others might > enter our observable universe if the Hubble rate decreases sufficiently > over time. The key factor is that the expansion rate evolves, altering the > fate of emitted light. > > Quentin > > All those moments will be lost in time, like tears in rain. (Roy > Batty/Rutger Hauer) > > Le mer. 19 mars 2025, 05:36, Alan Grayson <[email protected]> a écrit : > > > > On Tuesday, March 18, 2025 at 10:30:41 AM UTC-6 Quentin Anciaux wrote: > > Yes, I’m assuming spatial expansion, not just increasing galactic > distances. The observable horizon expands because the Hubble rate evolves > over time. > > > *So, are you now agreeing that the universe is spatially finite and > expanding, as distinguished from the model that the universe is infinite in > spatial extent while the average distance between galaxies in increasing? > AG * > > While some distant galaxies are receding faster than light, the expansion > rate is not constant, allowing light from previously unobservable regions > to eventually reach us. This is why our observable universe continues to > grow. > > > *So, for some photons emitted from a galaxy in the unobservable region, > they never reach us since space in that region is expanding faster than > light speed, but others (emitted from different galaxies in the > unobservable region) will eventually reach us since the rate of expansion > slows as time progresses, such that the spatial expansion in their region > has slowed below light speed? AG * > > > As for black holes, when they eject material, it comes from the accretion > disk, not the interior. Excess inflowing matter, under extreme magnetic > fields and radiation pressure, is expelled before crossing the event > horizon. Once inside, nothing escapes. > > > *That might not be true if all the mass/energy of the universe originated > as a BH, which we can identify as the BB. Doesn't the ultra high > temperature with all mass/energy concentrated nearly as a spatial > singularity at this BB cause a BH to form? AG * > > > Already answered. > > > *Please copy and paste your answer.* > > > No, use your own fingers. > > > I forgot where that was posted. AG > > > * 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? What happens to the mass/energy of the unobservable > region? TY, AG* > > > Did you answer the above question? AG > Yes, multiple times. > > Quentin > > > Quentin > > All those moments will be lost in time, like tears in rain. (Roy > Batty/Rutger Hauer) > > Le mar. 18 mars 2025, 16:54, Alan Grayson <[email protected]> a écrit : > > > > On Monday, March 17, 2025 at 5:03:42 PM UTC-6 Quentin Anciaux wrote: > > I have been reflecting on the idea that our universe could be the interior > of a giant black hole, but several fundamental questions arise. > > How can this account for the apparent flatness of the universe, given that > a black hole’s interior should exhibit strong curvature? Observations > indicate that our universe is nearly flat, yet this hypothesis lacks a > clear mechanism to explain why. > > If we are inside a black hole, where is the boundary? A black hole's > internal space-time is inherently limited by the event horizon, yet our > observable universe does not show any indication of such a constraint. How > does this model reconcile the absence of an observable edge? > > Furthermore, in classical black hole physics, the event horizon expands > only when additional mass or energy is absorbed. In contrast, our > universe’s observable horizon grows over time without any apparent external > input. What mechanism would drive this expansion in a black hole framework? > > These points suggest that such a model would require an unconventional and > exotic space-time structure beyond classical general relativity. I would > appreciate any insights on how these issues could be addressed. > > Quentin > > All those moments will be lost in time, like tears in rain. (Roy > Batty/Rutger Hauer) > > > When you refer to the horizon expanding of the observable universe, are > you now assuming the universe is expanding spatially, rather than just the > average galactic distances increasing? BTW, I'm confused about how that > horizon increases spatially. Aren't the galaxies in the unobservable > regions receding faster than light speed, and this is the reason they're > unobservable for us? If so, how can the observable region increase so some > of them become part of the observable region? One other thing; I viewed a > video showing BH's releasing material when too much is inflowing. Is some > of this material from the interior, or is all of it inflowing material that > is rejected? 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/0534ced9-b434-4ba0-8d54-070aa9241fbfn%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/0534ced9-b434-4ba0-8d54-070aa9241fbfn%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/1f59ad4b-eafd-42e1-95f3-1d1626005f20n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/1f59ad4b-eafd-42e1-95f3-1d1626005f20n%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/CAMW2kAowSJaa-qONgc_sG9JsSUEWJXbkByQuLNLdZTL8xW-Qpg%40mail.gmail.com.
