*To recapitulate and clarify the argument:* *Firstly, by "universe" I mean the observable and unobservable regions defining our expanding bubble. **Since the universe is expanding, we could run to clock backward and imagine enclosing it in a sphere, say, establishing that the observable region is finite in spatial extent. (It's actually measured to have a radius of 46 BLY.)*
*As for the unobservable region. let's assume it's infinite in spatial extent. If so, this couldn't have occurred in sta**ges, say by expansion, since no matter how fast it might expand, or for how large a length of time, it would remain finite throughout, and could never achieve infinite status. Hence, the only way it could be infinite in spatial extent, would be for it to be UN-created. This option is falsified by the CMBR, which is predicted by the Big Bang. That is, empirical evidence affirms it had a starting time. Moreover, as previously argued, if it is now infinite in spatial extent, it would have had to expand *i*nstantaneously **to infinity. Since I consider this physically impossible -- which is my unproven and likely unprovable assumption -- by two lines of argument our bubble must be finite in spatial extent.** Finally, being finite in spatial extent, it cannot be flat, since that implies infinite in spatial extent (assuming it's not toroidal). General conclusion: no need to do any measurements. Using a purely logical argument, our bubble is finite in spatial extent and cannot have a flat global geometry. It's likely global geometry is **approximately spherical*,* since it's expanding in all directions from every point in spacetime and is approximately isotropic. 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 on the web visit https://groups.google.com/d/msgid/everything-list/aac1ca28-ab64-4381-b839-1a55128d862en%40googlegroups.com.
