On Wednesday, January 17, 2018 at 3:45:25 AM UTC-7, Lawrence Crowell wrote: > > On Tuesday, January 16, 2018 at 4:35:36 PM UTC-6, agrays...@gmail.com > wrote: >> >> >> >> On Sunday, January 14, 2018 at 9:57:14 AM UTC-7, John Clark wrote: >>> >>> On Sun, Jan 14, 2018 at 5:17 AM, <agrays...@gmail.com> wrote: >>> >>> > >>>> I recently viewed a documentary on Quasars. IIRC, they are interpreted >>>> as immense BH's with inflowing matter of galactic size to account for >>>> their >>>> brightness, and their redshift, applying Hubble's Law, indicates they are >>>> far removed, closer to the BB than any galaxies within our observable >>>> universe. Question: did galaxies form that early after the BB to account >>>> for the huge inflows of matter and brightness? TIA, AG >>>> >>> >>> Quasars formed very soon after the Big bang, almost embarrassedly soon. >>> A recently discovered quasar called J1342+0928 is 13.1 billion light years >>> away and was formed just 690 million years after the Big Bang, and yet it >>> is powered by a Black Hole of 800 million solar masses. Astronomers >>> have trouble explaining how a Black Hole could get that big that fast >>> by conventional stellar evolution, but if from day one the universe >>> already contained 100 solar mass Black Holes that would help a lot in >>> explaining how that could happen and maybe give us a hint at what Dark >>> Matter is too. >>> >> >> *Hard to believe it formed that soon and so huge. For it to be that >> bright, how much mass must be inflowing per unit time, say per second or >> year? Is that mass speculated to be from an already formed galaxy? TIA, AG* >> > > From the perspective of classical gravitation it might be thought that the > initial singularity fragmented into singularities of black holes in the > emergent cosmology. If we think of singularities as topological objects, > then their generation or destruction means topology changes. We might then > think of the demolition of the initial timelike singularity at time t = 0 > and the generation of spacelike singularites in Schwarzschild black holes > or mass-inflation singularities as an operation that changes topology. > Quantum gravity is then a theory described by cobordism. General relativity > does not permit this. So it is possible that black holes emerged in the > first few Planck units of time in the generation of this cosmology. >
What's the difference between a timelike and spacelike singularity? Also, these BH's are not the result of collapse of massive stars, since stars didn't exist at the time. What is the speculation of the cause of these BH's? And why would they be bright without any infalling matter? AG > > If so then some of them may have grown very quickly in the early universe. > As John Clark points out the occurrence of black hole in the 100 solar mass > range in black hole coalescent events observed by gravitational radiation > is also a bit of a head scratcher. It was not expected that black holes in > that mass range would exist. They may constitute black holes that did not > grow that much, while a few grew into behemoths. > > LC > > >> >>> >>> We know from the percentage of the elements Hydrogen, Deuterium, Helium >>> and Lithium in existence how much regular matter was around one minute >>> after the Big Bang when nucleosynthesis cooked up these elements, and there >>> is no room for Dark Matter. So the Black Holes that form the bulk of the >>> Dark Matter can't have come from the corpses of dead stars made of regular >>> matter; but maybe Black Holes formed long before nucleosynthesis occurred >>> when the universe was much less than one minute old and things were too hot >>> for even protons to exist much less elements. >>> >>> Stephen Hawking proposed this explanation for Dark Matter some years ago >>> but the idea had fallen out of favor because it was largely (but not >>> entirely) ruled out by the data. We know that to account for all the Dark >>> Matter the Black Holes can't be larger than 100 solar masses because there >>> would be more gravitational microlensing than we observe. And we know that >>> to account for all the Dark Matter the Black Holes can't be smaller than 10 >>> solar masses because we'd see Black Hole explosions / evaporations (if they >>> were REALLY small) and the orbits of widely spaced binary stars would be >>> disrupted, but we don't see any of that. >>> >>> But there is still a window for Primordial Black Holes being Dark Matter >>> that the data hasn't excluded and it's between 10 and 100 solar masses, and >>> that's just what LIGO discovered. LIGO has so far detected 6 collisions >>> between Black Holes ranging in size between 36 and 7 solar masses resulting >>> in Black Holes of 18, 21, 35, 49, 53, and 62 solar masses. So maybe 85% of >>> all the matter in the universe is in the form of Primordial Black Holes. >>> >>> >>> 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 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.
