On Sunday, October 18, 2020 at 10:11:15 AM UTC-5 agrays...@gmail.com wrote:
> > > On Sunday, October 18, 2020 at 6:09:39 AM UTC-6, John Clark wrote: >> >> On Sun, Oct 18, 2020 Alan Grayson <agrays...@gmail.com> wrote: >> >> *> If the very early universe is a hot photon gas, wouldn't that be a >>> very high entropy initial condition?* >> >> >> That would be true if gravity was not an important factor as is the case >> for most experiments we can produce in the lab where gravity can be safely >> ignored, but in the very early universe gravity was enormously important >> and can not be ignored. >> > > > *In Boltzmann's formula for entropy, gravity isn't a parameter. I think > entropy only depends on the number of possible microstates, and therefore > on the volume. AG * > Totally wrong. Entropy is given by the area of a black hole, where the area is A = 4πr^2 and r = 2GM/c^2 or just 2m. Gravity is equivalent to temperature and T = 1/8πm. LC > > The early universe was very smooth but, due to random quantum variations, >> not perfectly smooth. So some parts of the universe had very slightly more >> mass/energy than other parts. As time progressed, because of gravity, the >> slightly denser regions pulled in slightly more particles into themselves >> than the slightly less dense regions did, and so those tiny variations >> started to grow larger. As a result of that growth of variations entropy >> increased and the Universe never again reached the very low entropy level >> it had when it was young. >> >> *> For a given volume, the entropy is what it is, related to the possible >>> microstates as given by Boltzmann's formula. If the volume increases, the >>> entropy increases, and it starts at a maximum level depending on the volume >>> of the very early universe. So I see no distinguishing the Actual Entropy >>> from the Maximum Possible Entropy. AG* >> >> >> The point is that if the universe is expanding (and accelerating) then >> there is no such thing as the universe having a Maximum Possible Entropy, >> whatever entropy value you give me no matter how large I can show you a >> time when the universe will have an even larger entropy. >> > > *The concept of Maximum Possible Entropy was introduced by Jason, via his > reference, and shown schematically in his diagram. Supposedly it can be > compared with actual entropy at any time. I have no idea what this means. > AG * > >> >> John K Clark >> > -- 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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/216240cf-f75a-4169-b2a4-d64bcd71f0ebn%40googlegroups.com.
