On Saturday, September 14, 2024 at 2:31:39 PM UTC-6 Brent Meeker wrote:
On 9/14/2024 12:30 AM, Alan Grayson wrote: But it's not a property of an expanding sphere without the condition that the expansion has a constant proportional rate; so the relative distances keep the same proportions. The further away something is the faster it is moving away. That's why your first assumption ds/dt=const gives a result inconsistent with Hubble's law, it doesn't keep theta constant for every point. Brent I never assumed ds/dt = const. Rather I calculated ds/dt and found it not surprisingly positive, which I concluded was insufficient to show ds/dt would eventually be > c. AG Hubble's law or something equivalent is necessary to give more definition to the problem. The balloon model does the same as Hubble's law; it posits that the expansion preserves proportions, i.e. if s=>s+ds then n*s=>n*s +n*ds. Brent I recall from years ago the proportion issue we discussed. Obviously, if r, the radius of sphere, increases by x%, so will any great circle on the sphere since its circumference also increases by x%, given the formula for circumference 2*pi*r. So, Hubble's measurements indirectly imply that the global geometry of the universe is spherical. 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/c365bcaa-cca1-4ed3-9d45-c0ff347dac59n%40googlegroups.com.
