On Monday, December 11, 2017 at 3:09:19 PM UTC, Lawrence Crowell wrote: > > On Sunday, December 10, 2017 at 8:07:15 PM UTC-6, Brent wrote: >> >> >> >> On 12/10/2017 5:25 PM, Lawrence Crowell wrote: >> >> >> >> On Sunday, December 10, 2017 at 5:13:38 PM UTC-6, [email protected] >> wrote: >>> >>> >>> >>> On Sunday, December 10, 2017 at 10:54:11 PM UTC, Lawrence Crowell wrote: >>>> >>>> >>>> >>>> On Sunday, December 10, 2017 at 3:34:33 PM UTC-6, [email protected] >>>> wrote: >>>>> >>>>> >>>>> >>>>> On Saturday, December 9, 2017 at 2:17:38 PM UTC, Lawrence Crowell >>>>> wrote: >>>>>> >>>>>> On Saturday, December 9, 2017 at 7:34:29 AM UTC-6, >>>>>> [email protected] wrote: >>>>>>> >>>>>>> >>>>>>> I think you're making the unwarranted assumption that the measured >>>>>>> shift in H is not >>>>>>> effected by the cosmological red shift which presumably shifts all >>>>>>> wave lengths. AG >>>>>>> >>>>>> >>>>>> Of course it shifts all wavelengths by the same factor. So the >>>>>> spectrum of atoms are shifted accordingly. With v = Hd the red shift >>>>>> factor >>>>>> is z = v/c = H(d/c). for H = 70km/s/Mpc for v = c we then have that d = >>>>>> c/H >>>>>> = 3x10^{5}km/s/(70Mpc/km/s) = 4.3x10^3Mpc = 1.4x10^{10}ly. So at z = 1 >>>>>> there lies the cosmological horizon. We now observe galaxies with z = 8 >>>>>> and >>>>>> the CMB has z = 1100. One can however thing of these photons as emitted >>>>>> prior to these systems crossing the horizon. >>>>>> >>>>>> LC >>>>>> >>>>> >>>>> Since a parsec is about 3.26 LY and the SoL is about 300,000 km/sec, >>>>> the event horizon should be about 300,000/70 * 3.26 * 10^6 = 13971 * 10^6 >>>>> LY =~ 13971 MLY = 13.971 BLY. But this is a far cry from about 50 BLY, >>>>> which is what I think the true distance is to the event horizon. I >>>>> probably >>>>> didn't account for the intervening expansion. How is accurate calculation >>>>> done? TIA, AG >>>>> >>>> >>>> That is about it. There is a bit with significant figures for you might >>>> want to use c = 299800km/s. >>>> >>>> LC >>>> >>> >>> But isn't the event horizon much farther out, about 50 BLY? AG >>> >> >> No that is about where the CMB surface of last scatter lies. >> >> >> To clarify, you mean where it lies "*now"*; and *"now" *means the >> (universe wide) time at which the CMB is 2.7degK. >> >> Brent >> > > The photons we observe from the CMB were emitted prior to the ionized gas > crossing the cosmological horizon. We see it as it was 380k years after the > big bang, with this huge red shifting. This red shifting indicates that on > the Hubble frame this stuff is "way out there," in fact at about 47bly > beyond the horizon. > > LC >
If I make the correction you suggest, I will get about 13.8 BLY for the event horizon, which is the distance a photon would travel if it began its journey at t = 0, ignoring the intervening expansion. Is this coincidental? Moreover, the figure of 47 BLY is the current distance of the object which emitted said photon. So I don't have to worry about the CMB to calculate this value. I think I just need to integrate for the age of the universe, but I am not sure what the integrand should be. AG > > >> >> It has z = 1100 and is further out beyond the horizon. >> >> LC >> -- >> 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. >> >> >> -- 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.
