On Friday, September 20, 2024 at 4:37:26 PM UTC-6 Alan Grayson wrote:
On Friday, September 20, 2024 at 2:23:10 PM UTC-6 John Clark wrote: On Fri, Sep 20, 2024 at 11:09 AM Alan Grayson <[email protected]> wrote: *> Proof by Contradiction: If the universe is infinite in spatial extent, and came into being, that would be a type of singularity where it would have to instantaneously expand infinitely in spatial extent.* s *This entire business started by you asking what would happen at T=0 if the universe started running backwards and obviously, regardless of if space is finite or infinite, space would have to expand infinitely fast because at T=0 it would have a zero amount of time to expand from nothing to something.* *Not exactly. * *I figured that since the universe is expanding, we could run to clock backward and imagine enclosing it in a sphere, say, establishing that it is finite, hence **NOT** flat, since flat implies infinite in spatial extent. IOW, we can prove the universe is NOT flat using a purely logical argument. No need to do any measurements. I sent this analysis to a professor emeritus whose main interest is in cosmology who is associated with Case Western University. He replied that my analysis dealt only with the observable universe and that the universe could be infinite in spatial extent, presumably when one considers the unobservable part. I then realized that the unobservable part was very likely caused by Inflation, and therefore the entire universe would** remain finite** provided we ran the clock backward, prior to Inflation. **While considering these issues, I realized that a universe infinite in spatial extent must be uncreated, since no matter has fast it expands, and for how much time, it cannot expand to infinity in spatial extent. IOW, the concept of a created universe, one which comes into being, which is infinite in spatial extent, assumes a type of singularity which I believe is non-physical and can't be realized; namely, a universe which expands infinitely in spatial extent, * *instantaneously**! So, the professor apparently doesn't realize that his critique of my original analysis implies that his claim that the universe might **be infinite in spatial extent, contains an implicit denial it had a beginning, called the Big Bang. In sum, I believe the universe, our expanding bubble, is finite, not flat in its global geometry, and had a beginning which we can call the Big Bang. **I haven't written him again to relieve him of his apparent misconception, though I might. However, I did write Alan Guth about a week ago, asking if he assumed the entire universe, or just the observable part existed, when Inflation began, at around 10^-35 seconds after the Big Bang, when the universe was around the size of a proton, or possibly smaller. So far he hasn't replied. * *AG* *BTW, I don't agree that the universe would have to expand infinitely fast at T=0 to transition from nothing to something. If that were true, we could conclude that moving an object at rest to some non-zero velocity would require an infinite acceleration. AG* *And yes that is a singularity however in physics, unlike pure mathematics, when you run into a singularity what that is really telling you is that there is some unknown physics going on that you don't understand, or don't understand well enough. Everybody knows something is wrong but nobody knows what. * *By the way when people, like me, say that because of AI we're heading towards a Singularity they are using poetic license, things in general and society in particular won't really be changing infinitely fast, just faster than the human meat brain can comprehend. * John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis> e4b -- 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/2c3cf8ac-4585-4aa1-8766-c4182ac874afn%40googlegroups.com.
