On Tuesday, December 25, 2018 at 12:35:24 AM UTC, Jason wrote: > > > > On Mon, Dec 24, 2018 at 6:28 PM <[email protected] <javascript:>> wrote: > >> >> >> On Monday, December 24, 2018 at 9:47:52 PM UTC, Jason wrote: >>> >>> >>> >>> On Mon, Dec 24, 2018 at 4:04 PM <[email protected]> wrote: >>> >>>> >>>> >>>> On Monday, December 24, 2018 at 8:25:11 PM UTC, [email protected] >>>> wrote: >>>>> >>>>> >>>>> >>>>> On Monday, December 24, 2018 at 6:40:03 AM UTC, Brent wrote: >>>>>> >>>>>> >>>>>> >>>>>> On 12/23/2018 8:22 PM, [email protected] wrote: >>>>>> >>>>>> >>>>>> >>>>>> On Monday, December 24, 2018 at 3:50:33 AM UTC, Brent wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 12/23/2018 4:47 PM, [email protected] wrote: >>>>>>> >>>>>>> *If by "flat", you mean mathematically flat, like a plane extending >>>>>>> infinitely in all directions, as opposed to asymptotically flat like a >>>>>>> huge >>>>>>> and expanding sphere, you have to reconcile an infinitesimally tiny >>>>>>> universe at the time of the BB, and simultaneously an infinitely large >>>>>>> universe extending infinitely in all directions. AG* >>>>>>> >>>>>>> >>>>>>> All that's "infinitesimally tiny" is the visible universe. You must >>>>>>> know that the Friedmann equation just defines the dynamics of a scale >>>>>>> factor, not a size. >>>>>>> >>>>>> >>>>>> *Are you claiming the visible universe at the BB was infinitesimally >>>>>> tiny, but the non visible part was infinitely large (mathematically >>>>>> flat), >>>>>> or huge (asymptotically flat)? AG * >>>>>> >>>>>> >>>>>> Right. Although we can't be sure whether it is actually flat or just >>>>>> very big. >>>>>> >>>>>> Brent >>>>>> >>>>> >>>>> *OK. Agreed. We seemed to disagree on this in the past, but maybe we >>>>> miscommunicated. AG* >>>>> >>>> >>>> Here's what Ned Wright wrote. >>>> >>>> Is the Universe really infinite or just really big? >>>> >>>> We have observations that say that the radius of curvature of the >>>> Universe is bigger than 70 billion light years. But the observations allow >>>> for either a positive or negative curvature, and this range includes the >>>> flat Universe with infinite radius of curvature. The negatively curved >>>> space is also infinite in volume even though it is curved. So we know >>>> empirically that the volume of the Universe is more than 20 times bigger >>>> than volume of the observable Universe. Since we can only look at small >>>> piece of an object that has a large radius of curvature, it looks flat. >>>> The >>>> simplest mathematical model for computing the observed properties of the >>>> Universe is then flat Euclidean space. This model is infinite, but what we >>>> know about the Universe is that it is really big >>>> <http://www.astro.ucla.edu/~wright/HGTTG.html>. >>>> >>>> >>>> <http://www.astro.ucla.edu/~wright/cosmology_faq.html#top> >>>> >>>> *It is misleading. He's referring to the VISIBLE universe and concludes >>>> it might be infinite in spatial extent. Impossible due to its finite age. >>>> I >>>> wrote him about this, but never received a reply. AG* >>>> >>>> >>>> >>> It's only impossible if you believe the believe the big bang occurred >>> only at a point, rather than everywhere. >>> >>> Consider that every point in space sees everything else around it flying >>> away from it, such that if you rewound time, everything would return to a >>> single point centered at that location. But this is true for every point in >>> space, so the implication is that the BigBang didn't happen at one >>> particular location long in the past, but at every point, including the >>> period at the end of this sentence. >>> >> >> *You seem inclined to extreme hypotheses for which there is no data. AG * >> >>> >>> > This is the default "standard" model used used by cosmologists, it's > called the concordance model, or the Lambda-CDM model. There is significant > data for it. >
*I don't believe it. AG * > > Jason > -- 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
