Le mer. 12 févr. 2025, 09:55, Alan Grayson <[email protected]> a écrit :
> If the age of the universe is finite, which is generally believed, then no > matter how fast it expands, it can never become spatially infinite, So,* > IF* it is spatially infinite, this must have been its initial condition > at or around he time of the Big Bang (BB). But this contradicts the > assumption that it was at a super high temperature at or around the time of > the BB. > AG, your assumption that a finite-age universe must be spatially finite is flawed. If the universe is infinite now, it was infinite at the Big Bang, just in a much hotter and denser state everywhere. The Big Bang wasn’t an explosion from a point but a transition from an extremely dense, uniform state, which applies whether the universe is finite or infinite. Eternal inflation suggests the universe was already infinite before the Hot Big Bang phase. The observable universe was once small and dense, but the entire universe could have been infinite at all times. Spatial flatness doesn’t imply finiteness—flat, infinite universes expanding from a dense state are fully consistent with general relativity. There’s no contradiction between a spatially infinite universe and high density at early times. The problem isn’t with cosmology—it’s with your mistaken assumption that high density requires finiteness. Quentin IOW, if we run the clock backward, the universe seems to get incredibly > small, and for *this reason* incredibly hot, roughly analogous to a > highly compressed gas. Therefore, it cannot have a flat global geometry, > since such a geometry is infinite in spatial extent. QED. 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/81398d3e-4195-4c46-b3b4-094812dd5898n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/81398d3e-4195-4c46-b3b4-094812dd5898n%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/CAMW2kAqZyV6fYYbSi-0p0VK3sdUM%3D%2B1ioK195LqQ5n8CmsrAiQ%40mail.gmail.com.
