Le mer. 11 sept. 2024, 09:14, Alan Grayson <[email protected]> a écrit :
> > > On Wednesday, September 11, 2024 at 12:41:56 AM UTC-6 Quentin Anciaux > wrote: > > To be clearer, imagine you have points drawn on the surface of a balloon. > As you inflate the balloon, the distance between two points increases, even > though the points themselves aren't moving across the surface of the > balloon. The farther apart the points are initially, the faster they seem > to be moving away from each other as the balloon inflates. Similarly, in > the universe, the farther away a galaxy is, the faster its recession > velocity, but this velocity is due to the expansion of space itself, not > because the galaxy is moving through space. > > Quentin > > > *If we imagine two separated galaxies on the equator of an expanding > sphere, the distance between them increases as the sphere expands. But the > light from either will reach the other, unless the distance is increasing > faster than c. How does your model guarantee that the distance is > increasing faster than c? AG * > Because the expansion is continuous as long as expansion rate is > 0, sooner or later distant object will receed faster than c. > > Le mer. 11 sept. 2024, 08:37, Quentin Anciaux <[email protected]> a > écrit : > > > > Le mer. 11 sept. 2024, 07:39, Alan Grayson <[email protected]> a écrit : > > > > On Tuesday, September 10, 2024 at 10:51:22 PM UTC-6 Quentin Anciaux wrote: > > > > Le mer. 11 sept. 2024, 00:06, Alan Grayson <[email protected]> a écrit : > > > > On Tuesday, September 10, 2024 at 3:50:08 PM UTC-6 Quentin Anciaux wrote: > > > > Le mar. 10 sept. 2024, 23:19, Alan Grayson <[email protected]> a écrit : > > > > On Tuesday, September 10, 2024 at 2:19:42 PM UTC-6 John Clark wrote: > > On Tue, Sep 10, 2024 at 3:57 PM Alan Grayson <[email protected]> wrote: > > > *>> Even if you ignore Dark Energy and postulate that the Hubble constant > really is constant, every object a megaparsec away (3.26 million > light-years) is moving away from us at about 70 kilometers per second. So > if you try to look at objects a sufficiently large number of megaparsec > away you will fail to find any because they are moving away from us faster > than the speed of light.* > > > >* That was in the past. At present, the universe is expanding at about > 70 km/sec.* > > > *Galaxies are receding from the Earth at 70 km/sec for EACH megaparsec > distant from Earth they are. The further from Earth they are, the faster > they are moving away from us, so if they are far enough away they will be > moving faster than the speed of light away from us. * > > *> You're assuming the universe today is infinite,* > > > *NO! I said IF the entire universe is infinite today then it was always > infinite, and IF it was finite 10^-35 seconds after the Big Bang then it's > still finite today. I also said nobody knows if the entire universe is > infinite or finite. * > > > *>* *Hubble's law applies to the past, not to the future,* > > > *What the hell?! * > > > *How about an intelligent reply? Obviously, if the universe is infinite > today, it was always infinite. But that's what I am questioning. For > galaxies to fall out of view, they have to moving at greater than c. Now > they aren't receding that fast. How will they start moving that fast? > You're applying Hubble's law without thinking what it says. Just because a > galaxy is now receding at less than c, how will continued expansion > increase that speed to greater than c? AG * > > > The farther they are the faster they are receding from you, so as they > continue to get farther away they receed faster from you till the point > they receed faster than c and go out of your horizon. > > Quentin > > > *That's the conventional wisdom but what is the physical mechanism? Hubble > discovered that the universe was expanding faster in the past, than in the > present. Now its rate of expansion is much slower, allowing us to see many > distant galaxies. What is the physical mechanism that will cause its > present expansion rate to increase to greater than c* > > > The expansion rate can still be the same or even slow down that my > explanationis still valid, no need for the *expansion rate* to change for > current objects near the horizon to soon recess at more than c. > > > *You haven't explained anything. You're just repeating what you've heard > or read. A long time ago Brent explained it as a purely geometric result of > the expansion, but now I tend to doubt that explanation. Specifically, if a > galaxy now relatively close and visible but due to the expansion moves, > say, into a region where the recessional velocity HAD BEEN some multiple of > its recessional velocity when relatively near the Milky Way, why does its > recessional velocity increase? AG * > > > Because expansion is everywhere the same, take the inflated balloon > example, any two points are receeding faster from each other as the balloon > inflate at a constant rate, and again it's not the objects that are going > at +c, but the space between those objects that expand. > > > *, so distant galaxies will be beyond our field of view? AG* > > * John* K Clark See what's on my new list at Extropolis > <https://groups.google.com/g/extropolis> > > hwt > > > -- > 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/5485c7a2-a527-448a-b337-3c8c60466d73n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/5485c7a2-a527-448a-b337-3c8c60466d73n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > -- > 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/24def9fe-4c08-4736-b06b-620bca816d35n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/24def9fe-4c08-4736-b06b-620bca816d35n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > -- > 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/afaaab86-7c74-41b4-ba15-8daca021db73n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/afaaab86-7c74-41b4-ba15-8daca021db73n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > -- > 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/c7f0e3dc-ede1-4df6-9690-b3ddec26d0fdn%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/c7f0e3dc-ede1-4df6-9690-b3ddec26d0fdn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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