On Mon, Sep 16, 2019 at 3:31 AM Alan Grayson <agrayson2...@gmail.com> wrote:
> > > On Wednesday, September 11, 2019 at 10:45:41 PM UTC-6, Alan Grayson wrote: >> >> >> https://www.wired.com/story/sean-carroll-thinks-we-all-exist-on-multiple-worlds/ >> > > Jason; it turns out you were right about the consensus among cosmologists; > that the universe is thought to be *flat*. But I am studying some videos > which seem to suggest that a flat universe can be* finite* in spatial > extent, maybe like a cyclinder without an edge. Try try this, and the two > which follow: > > https://www.youtube.com/watch?v=_k3_B9Eq7eM&feature=youtu.be > > That is interesting and it is a good reminder how how flexible math is to representing various spaces and geometries. Most cosmologists work under the assumption that space is "simply connected", rather than doughnut shaped or otherwise, in which case if space is simply connected, and flat, then it ought to be infinite. There are also interesting things that can be done as far as compacting space, so that a finite cylinder can represent an infinite space evolving through time. There are some good illustrations of this here: https://www.podevin.com/single-post/2019/01/24/Einsteins-Dream-of-a-Grand-Unified-Theory Also known as a "Poincare disk" https://en.wikipedia.org/wiki/Poincar%C3%A9_disk_model http://mathworld.wolfram.com/PoincareHyperbolicDisk.html 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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CA%2BBCJUhTZNp-9YxWbufHrUUOr6-QiOmopqyy-ix%3DWmjK%2BJzoLg%40mail.gmail.com.
