On the stackexchange I presented <https://physics.stackexchange.com/questions/257476/how-did-the-universe-shift-from-dark-matter-dominated-to-dark-energy-dominate/257542#257542> FLRW cosmology. The important equation is
(a'/a)^2 = 4πGρ/3 for a' = da/dt. The parameter a is a scale factor and the distance and velocity of a distant galaxy is v = xa' and d = xa. This equation also is the same as (a'/a)^2 = H^2 or that v = Hd. This is the Hubble relationship with the Hubble parameter H. The x in this is the standard ruler. This is determined by other means. The earliest such ruler was from Cepheid variables. Now for great distances type I supernovae are used. The value of the Hubble parameter is about 70m/s-Mpc. However as I indicated in my post on the big rip there is a growing chasm between this value as determined by the CMB and by galactic measurements. LC https://physics.stackexchange.com/questions/257476/how-did-the-universe-shift-from-dark-matter-dominated-to-dark-energy-dominate/257542#257542 On Friday, December 8, 2017 at 9:04:42 AM UTC-6, agrays...@gmail.com wrote: > > How is it distinguished from red and possibly blue shifting due to > relative motion of distant galaxies? TIA, 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 everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
