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. 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.
