On Friday, August 23, 2019 at 8:12:55 PM UTC-6, Lawrence Crowell wrote: > > On Friday, August 23, 2019 at 9:01:42 PM UTC-5, Alan Grayson wrote: >> >> >> >> On Friday, August 23, 2019 at 7:48:19 PM UTC-6, Lawrence Crowell wrote: >>> >>> On Friday, August 23, 2019 at 5:48:13 PM UTC-5, Alan Grayson wrote: >>>> >>>> >>>> >>>> On Friday, August 23, 2019 at 3:31:36 PM UTC-6, Lawrence Crowell wrote: >>>>> >>>>> On Thursday, August 22, 2019 at 12:37:40 AM UTC-5, Alan Grayson wrote: >>>>>> >>>>>> >>>>>> >>>>>> On Wednesday, August 21, 2019 at 7:12:14 PM UTC-6, Alan Grayson wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Wednesday, August 21, 2019 at 3:13:11 PM UTC-6, Lawrence Crowell >>>>>>> wrote: >>>>>>>> >>>>>>>> On Tuesday, August 20, 2019 at 4:56:23 PM UTC-5, Alan Grayson wrote: >>>>>>>>> >>>>>>>>> https://en.wikipedia.org/wiki/Conformal_cyclic_cosmology >>>>>>>>> >>>>>>>>> Is this a viable theory for avoiding a BB interpreted as a >>>>>>>>> singularity? AG >>>>>>>>> >>>>>>>> >>>>>>>> Penrose proposed a conformal identification of spatial infinity in >>>>>>>> the past and future i^±∞ of FLRW spacetimes. A cosmology expands and >>>>>>>> in the >>>>>>>> limit time → ∞ it transitions into a new cosmology. The de Sitter >>>>>>>> vacuum is >>>>>>>> not eternally stable, so the idea may have some germ of relevancy. I >>>>>>>> am not >>>>>>>> sure about how this would work with vacuum to vacuum transitions. The >>>>>>>> exponential expansion of the universe is a sort of time dependent >>>>>>>> conformal >>>>>>>> transformation with a small vacuum expectation for the scale field. To >>>>>>>> transition to a new cosmology, say with inflationary expansion, this >>>>>>>> means >>>>>>>> the vacuum expectation is increased. >>>>>>>> >>>>>>>> The overall physics community response to this has been tepid at >>>>>>>> best. There are some possible conflicts with observed data. >>>>>>>> >>>>>>>> LC >>>>>>>> >>>>>>> >>>>>>> FWIW, ISTM that what GR might be indicating about the BB, is that, >>>>>>> insofar as it's a singularity, it couldn't have occurred, and didn't >>>>>>> occur. This is to say the universe didn't become infinitely small in >>>>>>> spatial extent, like a mathematical point, but rather that there was a >>>>>>> maximal finite value of its energy density, hugely high but not >>>>>>> infinite. >>>>>>> For this reason I find the cyclic models promising, although, as you >>>>>>> rightly indicate, they're far from complete or bug-free. AG >>>>>>> >>>>>> >>>>>> Which brings up a possibly relevant question: If the total energy of >>>>>> the universe occupied zero spatial volume (the presumed condition of the >>>>>> universe at t=o according to the BB theory), wouldn't that contradict >>>>>> the >>>>>> Uncertainty Principle? AG >>>>>> >>>>> >>>>> The total mass-energy content of the universe is zero. >>>>> >>>>> LC >>>>> >>>> >>>> Is that a provable fact, or something that can be measured? TIA, AG >>>> >>> >>> It is provable, because in general spacetimes there does not exist a >>> Gaussian surface to define mass. This sets the energy to zero. Think of it >>> as meaning gravitational potential energy as negative is equal in magnitude >>> to positive mass-energy. >>> >>> LC >>> >> >> If, using E=mc^2, one computes the rest energy of the material Earth, it >> seems implausible that this equals the negative potential energy of the >> Earth's gravitational field, to yield a net energy sum of zero. AG >> > > Consider the gravitation with expansion and cosmological constant. This > was first pointed out by Tolman many decades ago. > > LC >
I will. But maybe in the meantime you could explain how, using E=mc^2 and the negative potential energy of Earth's gravity field , you can get them to cancel out for an isolated Earth. Something very puzzling here. Additionally, ISTM that one would have an impossible task making a nuclear weapon from negative potential energy. What am I doing wrong, if anything? 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/bef9dcdc-53ae-4d60-85a3-8ea85d2be5e4%40googlegroups.com.
