On Monday, January 27, 2020 at 6:41:45 AM UTC-7, John Clark wrote: > > On Sun, Jan 26, 2020 at 9:49 PM Alan Grayson <[email protected] > <javascript:>> wrote: > > Note: At the end of this email I posted a picture, if anybody responds to > it PLEASE don't just hit the reply button, take 2 seconds to edit the > picture out so we don't get endless recursive iterations of it. > > >>Regardless of if space is positively curved or negatively curved or as >>> flat as a pancake, if the universe is accelerating and not just expanding >>> then galaxies in our OBSERVABLE region will eventually cross over our event >>> horizon into our UNOBSERVABLE region, >>> >> >> *> How many times must I say this? * >> > > 42. > > *> It does NOT depend on acceleration, just expansion, because the effect >> is purely geometrical, which I earlier explained.* [...] *So if you wan**t >> to calculate its radius, all you need is its curvature! -- which, I >> conjecture, will one day be able to be measured.* >> > > First of all, you'll never be able to measure exactly zero curvature and > prove it's flat, you might in principle be able to measure positive curvature > and show that the universe is spherically shaped, but in a expanding > accelerating universe that wouldn't prove the universe is finite. >
It sure would. If it's expanding at a finite rate for finite time (the age of the universe), how could it be other than finite? AG > You can fit an infinite volume inside a expanding sphere if you take > length contraction into account. > Failing to apply length contraction (and I'm not sure it is applicable in this situation), would just mean that the estimate without it would be too large, but not infinite. AG Einstein tells us that if the universe is a expanding sphere then the more > distant a star is from us the faster it will be moving away from us and > thus the thinner it will look to us, this is even more important if it's > not just expanding but accelerating. > Irrelevant IMO. AG > It's rather like one of M C Escher's "Circle Limit" series of 2D woodcuts > blown up to 3D. They're all great but take a look at Circle Limit III: > > > [image: image.png] > > > John K Clark > -- 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/7d076162-f0d7-4ed6-97da-37ad1e3cea6b%40googlegroups.com.
