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A quasar, too heavy to be true
https://www.nature.com/articles/nature25180
[[Mod. note -- Open-access preprint at https://arxiv.org/abs/1712.01860 -- jt]] Here we report observations of the quasar ULAS J134208.10+092838.61 (hereafter J1342+0928) at a redshift of z=7.54. This quasar has a bolometric luminosity of 4e13 Lsun and a black hole mass of 8e8 Msun. Wow! https://www.sciencedaily.com/release...1206131946.htm "This is the only object we have observed from this era," says Robert Simcoe, the Francis L. Friedman Professor of Physics in MIT's Kavli Institute for Astrophysics and Space Research. "It has an extremely high mass, and yet the universe is so young that this thing shouldn't exist. The universe was just not old enough to make a black hole that big. It's very puzzling." Exactly. It is at 690 My after the supposed "bang". Of course there is an explanation. The authors of the nature paper say that the big bang created black holes and the problem is solved: The big pre-existing black holes of the universe (with 10E4 solar masses) would have seeded this thing of course. How can gravity influence things in the searing hot universe coming from a big bang??? Before a certain point, not even light can travel isn't it? Before the decoupling? How can gravity influence anything at those temperatures? Mystery. Well anyway, the universe can do anything so let's suppose that. Why not see otherwise that there wasn't any bang at all and that we are seeing a very old quasar? The spectra correspond to a quasar. The simplest explanation is that this IS a quasar, a very old one. This implies that the universe must be at least 20-30 Gy old. What can be salvaged? Apparently, the red shift exists and it is an indicator of distance calibrated by other methods using Hubble by NASA. As far as I remember, in their "Origins" program. Many theories could explain that red shift, I just do not know which one will be accepted. And the CMB? Obviously it is there, but what it is, nobody knows. Yes, you can find harmonics, since foreground objects could generate those signatures. Or other explanations, depending on what you think you are seeing. From the outside I just see that the more we look, the more galaxies we find. 72 new ones were discovered in the HUDF just looking with a better instrument. And it goes on and on, and nobody knows if there is any limit. BB theory was adopted because it fitted observations. The cosmic background was thought as the relic radiation Gamow proposed. The explaining power of that theory was reinforced by a huge theoretical work figuring out how that bang would have happened. A book that impressed me more than 3 minutes told us the story... Since there wasn't any telescopes able to see as far as the modern ones, this agreement with observations lasted time enough to establish the theory as the only explanation. Today, we are seeing that the bang couldn't have happened at that date. We see old objects everywhere, that make the fatidic birth date of the universe appear as an error interpretation. Well, we will figure out a new explanation. But maybe it would be better if we recognize that we can only speak scientifically for observations. Astronomy is concerned with observations. Cosmology with the Universe as a whole, something that astronomy can't answer, it can only answer about the observed universe, a surely small portion of the Unknown. |
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A quasar, too heavy to be true
On Sun, 10 Dec 2017, jacobnavia wrote:
The authors of the nature paper say that the big bang created black holes and the problem is solved I am reminded of the creationists' thesis that fossils were part of the 6 days of creation. Not a pleasant similarity. [[Mod. note -- 1. The authors of the nature paper do NOT say that the big bang created black holes. Rather, they discuss "seed" black holes formed soon after the big bang (e.g., by the collapse of the first generation of super-massive stars). 2. The key difference between creationism and the present discussion is that creationists have no solid data & no scientific theory with which to study their claims or make unambiguous predictions. In contrast, there are * a lot of observations of high-redshift objects; * a scientific theory (the hot big bang model) which provides a framework for studying and reasoning about high-redshift objects, and which makes various unambiguous predictions (e.g., the CMB) which have proven to be correct; and * a prediction based on the hot big bang model + well-understood stellar-evolution theory that the first generation of stars in the universe were relatively massive and thus would have relatively short lifetimes before producing supernovae and black holes It may well be that there are difficulties constructing a quantitative theory for the formation of "black holes seeds of at least 1000 M_sun ... by z=40" (as the authors of the Nature paper put it). But these are *scientific* difficulties, and can be addressed by the normal methods of science (e.g., we can see if alternative scientific explanations work better). This is profoundly different from creationism. -- jt]] |
#3
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A quasar, too heavy to be true
In article , jacobnavia
writes: "This is the only object we have observed from this era," says Robert Simcoe, the Francis L. Friedman Professor of Physics in MIT's Kavli Institute for Astrophysics and Space Research. "It has an extremely high mass, and yet the universe is so young that this thing shouldn't exist. The universe was just not old enough to make a black hole that big. It's very puzzling." I just returned from the Texas Symposium on relativistic astrophysics. For a while now, there has been renewed interest in primordial black holes. These could a) be dark matter (see Carr et al arXiv:1607.06077 http://adsabs.harvard.edu/abs/2016PhRvD..94h3504C ) and b) perhaps seed larger black holes. Exactly. It is at 690 My after the supposed "bang". You need to come up with more evidence than "supposed" and scare quotes to make your case. How can gravity influence things in the searing hot universe coming from a big bang??? Do the maths. How can gravity influence anything at those temperatures? Stuff is much more dense back then. Why not see otherwise that there wasn't any bang at all and that we are seeing a very old quasar? Because of a huge amount of evidence that points to the more standard scenario. The spectra correspond to a quasar. The simplest explanation is that this IS a quasar, a very old one. This implies that the universe must be at least 20-30 Gy old. Calculation, please. Many theories could explain that red shift, I just do not know which one will be accepted. There is no other viable explanation than the cosmological redshift. Obviously it is there, but what it is, nobody knows. Yes, you can find harmonics, since foreground objects could generate those signatures. Or other explanations, depending on what you think you are seeing. Give me ONE other theory which PREDICTS the CMB power spectrum. From the outside I just see that the more we look, the more galaxies we find. 72 new ones were discovered in the HUDF just looking with a better instrument. And it goes on and on, and nobody knows if there is any limit. Even in the big-bang scenario, the universe can be infinite. |
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A quasar, too heavy to be true
On 10/12/2017 21:29, jacobnavia wrote:
https://www.nature.com/articles/nature25180 [[Mod. note -- Open-access preprint at https://arxiv.org/abs/1712.01860 -- jt]] Here we report observations of the quasar ULAS J134208.10+092838.61 (hereafter J1342+0928) at a redshift of z=7.54. This quasar has a bolometric luminosity of 4e13 Lsun and a black hole mass of 8e8 Msun. Wow! https://www.sciencedaily.com/release...1206131946.htm "This is the only object we have observed from this era," says Robert Simcoe, the Francis L. Friedman Professor of Physics in MIT's Kavli Institute for Astrophysics and Space Research. "It has an extremely high mass, and yet the universe is so young that this thing shouldn't exist. The universe was just not old enough to make a black hole that big. It's very puzzling." Exactly. It is at 690 My after the supposed "bang". Of course there is an explanation. The authors of the nature paper say that the big bang created black holes and the problem is solved: The big pre-existing black holes of the universe (with 10E4 solar masses) would have seeded this thing of course. You wouldn't need very many such seeds to meet the observational constraints. Only one other quasar is known at that sort of redshift. There may be others but we will only be able to see the very brightest ones or those that by sheer luck are gravitationally lensed. How can gravity influence things in the searing hot universe coming from a big bang??? Gravity influences things right from the very start. It doesn't really have much of a bite until things cool to below 4000K and Z~1000 in the recombination era and there is a decent proportion of transparent neutral hydrogen gas with photons able to travel freely some distance. There is a very large gap between Z=7.5 (this quasar) and Z=1000. Before a certain point, not even light can travel isn't it? The universe is opaque until the universe cools to allow neutral hydrogen when it becomes transparent. Later during the star formation era it is partially re-ionised by the UV from the first stars. It looks like this quasar is far enough away that its light has to pass through some of this newly reionised material which makes it an interesting probe into the early universe. Absorption spectra will show one heck of a Lyman forest and other interesting features. Before the decoupling? How can gravity influence anything at those temperatures? It is always an attractive force. Mystery. Well anyway, the universe can do anything so let's suppose that. Why not see otherwise that there wasn't any bang at all and that we are seeing a very old quasar? Quasars and radio galaxies are intrinsically quite young. The huge numbers of them at moderate redshifts and shortage of them nearby was one of the things that killed the Steady State theories stone dead. The spectra correspond to a quasar. The simplest explanation is that this IS a quasar, a very old one. It was very young when the light left it. Very young indeed. It is possible that it is Kerr metric feeding at its optimum rate and we are looking at it from the most favourable possible angle to see it at all. This implies that the universe must be at least 20-30 Gy old. It implies nothing of the sort. -- Regards, Martin Brown |
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A quasar, too heavy to be true
In article ,
jacobnavia writes: https://www.nature.com/articles/nature25180 [[Mod. note -- Open-access preprint at https://arxiv.org/abs/1712.01860 The Nature article is still preliminary and has some typos in it. The preprint doesn't have those, and the figures are better. Here we report observations of the quasar ULAS J134208.10+092838.61 (hereafter J1342+0928) at a redshift of z=7.54. This quasar has a bolometric luminosity of 4e13 Lsun and a black hole mass of 8e8 Msun. It is at 690 My after the supposed "bang". The big pre-existing black holes of the universe (with 10E4 solar masses) would have seeded this thing of course. Fig 2 of the paper shows that seeds need to be 1000 Msun at z=40 or 1E4 Msun (not 10E4) at z=22 or so if the subsequent accretion is at Eddington rate. Temperature at z=40 is about 112 K (hardly "searing hot"). I invite you to calculate the Jeans mass at these redshifts. I don't think anyone knows how the initial seed black holes formed or what their mass distribution was, but why should it be impossible to form the seeds as suggested above? At least on current knowledge, there don't have to be very many of them. There's also the alternative of super-Eddington accretion. While there's some evidence for that at lower redshifts, it seems less likely than high-mass seeds. -- Help keep our newsgroup healthy; please don't feed the trolls. Steve Willner Phone 617-495-7123 Cambridge, MA 02138 USA |
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A quasar, too heavy to be true
In article ,
Martin Brown writes: The universe is opaque until the universe cools to allow neutral hydrogen when it becomes transparent. I'm afraid that's backwards. The universe starts out with opacity dominated by scattering. After recombination (a slight misnomer -- that epoch is the first appearance of atoms), the universe was opaque to ultraviolet light. Only after reionization did the universe become transparent to UV. That corresponds to redshifts of something like 6 to 9 or so, but the details are not yet known. Reionization was almost certainly patchy so occurred at different times in different locations. -- Help keep our newsgroup healthy; please don't feed the trolls. Steve Willner Phone 617-495-7123 Cambridge, MA 02138 USA [[Mod. note -- Maybe there's a confusion here about wavelengths. Is this chart correct? visible/IR hard UV before recombination opaque opaque (roughly z 1100) between recombination & reionization transparent opaque (roughly 8 z 1100) after reionization transparent transparent (roughly z 8) Here "hard UV" means UV with a photon energy high enough that H atoms can be photoionized. -- jt]] |
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A quasar, too heavy to be true
Le 15/12/2017 Ã* 05:33, Steve Willner a écritÂ*:
Fig 2 of the paper shows that seeds need to be 1000 Msun at z=40 or 1E4 Msun (not 10E4) at z=22 or so if the subsequent accretion is at Eddington rate. Temperature at z=40 is about 112 K (hardly "searing hot"). 1) At z = 1000 we have a temperature of 2,728 degrees... Completely new and unknown processes must have been at work to form structures like a black hole at those temperatures. And nothing less than a black hole of 1E4 solar masses. It seems (to me) impossible that gravity can condense something at those temperatures. 2) At z = 40 we have a temperature of 112 K. Star formation happens in clouds with temperatures between 10 to 20 K. Yes, 112 K is not "searing hot", but hot enough to make star formation impossible. 3) If we assume that star formation could happen at 50 K, i.e. at z = 17, approx 228 My after the bang, that leaves 690 - 228 --462 My to form a black hole that has an 800 Msun mass... I am not saying that BB theory is impossible. I am just saying that explaining observations within that framework becomes more and more difficult, requiring more and more "ad hoc" hypothesis (now we have primordial black holes) and requiring explanations that look less and less probable. And observations that contradict the bang start coming almost daily now. ALMA has seen a galactic collision at 780 My and the two galaxies are very dusty and huge... I will post another article about that. |
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A quasar, too heavy to be true
In article , jacob navia
writes: 1) At z = 1000 we have a temperature of 2,728 degrees... Completely new and unknown processes must have been at work to form structures like a black hole at those temperatures. Perhaps different than for stellar-mass black holes, but not necessarily completely new and unknown. And nothing less than a black hole of 1E4 solar masses. It seems (to me) impossible that gravity can condense something at those temperatures. Then read up on your physics. 2) At z = 40 we have a temperature of 112 K. Star formation happens in clouds with temperatures between 10 to 20 K. Yes, 112 K is not "searing hot", but hot enough to make star formation impossible. Not all black holes must form from stars. 3) If we assume that star formation could happen at 50 K, i.e. at z = 17, approx 228 My after the bang, that leaves 690 - 228 --462 My to form a black hole that has an 800 Msun mass... Not all black holes must form from stars. I am not saying that BB theory is impossible. I am just saying that explaining observations within that framework becomes more and more difficult, requiring more and more "ad hoc" hypothesis (now we have primordial black holes) Primordial black holes are neither an ad-hoc hypothesis nor were they thought of first to explain this observation. Do a literature search for "primordial black holes". and requiring explanations that look less and less probable. By which measure? And observations that contradict the bang start coming almost daily now. ALMA has seen a galactic collision at 780 My and the two galaxies are very dusty and huge... I will post another article about that. You have been claiming this for years, but have never come up with anything which convincingly contradicts the big bang. |
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A quasar, too heavy to be true
[[Mod. note -- I apologise for the delay in processing this article.
It arrived in my moderation queue on 2017-12-18, just before an extended power/internet outage at my location. -- jt]] In article , jacob navia writes: 1) At z = 1000 we have a temperature of 2,728 degrees... Completely new and unknown processes must have been at work to form structures like a black hole at those temperatures. And nothing less than a black hole of 1E4 solar masses. It seems (to me) impossible that gravity can condense something at those temperatures. A star can have a central temperature of tens of millions of degrees, yet gravity manages to condense the star into a black hole as soon as fusion can't generate enough radiation pressure to balance gravity. |
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A quasar, too heavy to be true
[[Mod. note -- I apologise for the delay in processing this article.
It arrived in my moderation queue on 2017-12-18, just before an extended power/internet outage at my location. -- jt]] On Sunday, December 17, 2017 at 1:18:58 PM UTC-7, Phillip Helbig (undress to reply) wrote: In article , jacob navia writes: 1) At z = 1000 we have a temperature of 2,728 degrees... Completely new and unknown processes must have been at work to form structures like a black hole at those temperatures. Perhaps different than for stellar-mass black holes, but not necessarily completely new and unknown. And nothing less than a black hole of 1E4 solar masses. It seems (to me) impossible that gravity can condense something at those temperatures. Then read up on your physics. 2) At z = 40 we have a temperature of 112 K. Star formation happens in clouds with temperatures between 10 to 20 K. Yes, 112 K is not "searing hot", but hot enough to make star formation impossible. Not all black holes must form from stars. 3) If we assume that star formation could happen at 50 K, i.e. at z = 17, approx 228 My after the bang, that leaves 690 - 228 --462 My to form a black hole that has an 800 Msun mass... Not all black holes must form from stars. I am not saying that BB theory is impossible. I am just saying that explaining observations within that framework becomes more and more difficult, requiring more and more "ad hoc" hypothesis (now we have primordial black holes) Primordial black holes are neither an ad-hoc hypothesis nor were they thought of first to explain this observation. Do a literature search for "primordial black holes". and requiring explanations that look less and less probable. By which measure? And observations that contradict the bang start coming almost daily now. ALMA has seen a galactic collision at 780 My and the two galaxies are very dusty and huge... I will post another article about that. You have been claiming this for years, but have never come up with anything which convincingly contradicts the big bang. Well, maybe no outright contradicting the BB, but it doesn't agree with the experimental evidence without inflation: "Inflation isn't falsifiable, it's falsified -- BICEP did a wonderful service by bringing all the Inflationists out of their shell, and giving them a black eye." - Roger Penrose "Even from the beginning, inflation looked like a kluge to me-- I rapidly formed the opinion that these guys were just making it up as they went along" -- Neil Turok And a "singularity" is certainly unphysical. It means the physics has broken down. It would seem that alternatives might exist: https://www.edge.org/conversation/pa...aul-steinhardt http://clearlyexplained.com/answers/membranetheory.html |
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