Le mar. 10 sept. 2024, 15:43, Alan Grayson <[email protected]> a écrit :
> > > On Tuesday, September 10, 2024 at 6:32:37 AM UTC-6 John Clark wrote: > > On Mon, Sep 9, 2024 at 9:54 PM Alan Grayson <[email protected]> wrote: > > *> the rate of expansion of the universe appears to be increasing, * > > > *Yes but even if the rate of expansion stopped increasing it would still > be true that some galaxies we can see today we won't be able to see > tomorrow. * > > > *But you haven't explained WHY that is the case. AG * > > > *> is it increasing fast enough to cause galaxies in our local group to > become part of the UNobservable universe?* > > > *We are already part of the unobservable universe to galaxies that we > cannot see. None of the galaxies in the local group are moving away from us > because the local group is gravitationally bound together, that is to say > the mutual gravitational attraction between its members is strong enough to > overcome the general expansion of the universe. But there are only about 80 > galaxies in our local group, the three largest in order of size are > Andromeda, the Milky Way and the Triangulum Galaxy. 77 are just dwarf > galaxies. Except for those, all the other galaxies in the universe are > moving away from us.* > > > > * > I conjecture that the UNobservable universe came into being with > Inflation. If so, it must have been initially finite in spatial extent* > > > *If the entire universe, observable plus unobservable, is infinite today > then it must've been infinite even before inflation started, it must've > been infinite from the first Planck Time Instant of its creation. I think > most cosmologists would say that at the largest level space is curved into > some unknown shape but inflation has flattened it out so much the curvature > is too small to ever be detected. * > > > *You're assuming what I'd like to see argued. Guth says Inflation started > at t = 10^-35 seconds and the universe was around the size of a proton. * > The actual observable universe was the size of a proton, for all we know it could be infinite in size at that rime, but the region of our observable universe was at that time the size of a proton... inflation maybe eternal and stopped only in our region. *I think the huge expansion created the unobserved region since space must > have expanded greater than the speed of light. AG * > > > > *They used to say there was a strict relationship between the amount of > mass/energy in the universe and its shape, if it was less than a certain > figure it was positively curved like a sphere, if it was over that figured > it was negatively curved like a saddle, and if it was EXACTLY at that > figure it was flat; but after the discovery of Dark Energy things became a > lot more complicated and they knew that simple relationship could not be > true. * > > *By the way, there is some indication that Dark Energy is getting weaker > and thus the acceleration of the universe is slowing down, but there's not > enough evidence to claim a discovery and get a Nobel prize; it only has 3.9 > sigma, enough to be very exciting but you need at least 5 sigma to claim a > discovery. If that turns out to be true then all bets are off and we have > no idea what the distant future will be like, for all we know after Dark > Energy drops to zero it may turn negative and Dark Energy might start > slowing down the expansion of the universe. Nobody knows.* > > *Dark Energy May Be Weakening, Major Astrophysics Study Finds* > <https://www.quantamagazine.org/dark-energy-may-be-weakening-major-astrophysics-study-finds-20240404/?mc_cid=27ab9f2b7c&mc_eid=1b0caa9e8c> > > John K Clark See what's on my new list at Extropolis > <https://groups.google.com/g/extropolis> > ba0 > > > > -- > 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/71236162-e994-4ccf-9497-1ea622250840n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/71236162-e994-4ccf-9497-1ea622250840n%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 on the web visit https://groups.google.com/d/msgid/everything-list/CAMW2kAqS3T4kR9kbku4FJP7F15_LFk2Y8RD7q0eFJ-ozzaAyVA%40mail.gmail.com.
