James Webb Telescope discovers some quasars that seem to exist in isolation(scitechdaily.com)
scitechdaily.com
James Webb Telescope discovers some quasars that seem to exist in isolation
https://scitechdaily.com/james-webb-telescope-discovers-quasars-where-they-shouldnt-exist/
70 comments
I would assume that given the extreme redshift this can be explained by the combination of acoustic oscillation overdensities and gravothermal catastrophe but there is probably some unmentioned reason why it can't.
This sounds like a line stolen from an old Star Trek script, FWIW. For those who need more context, the ideas here are real:
https://physics.stackexchange.com/questions/249679/gravother... https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations
https://physics.stackexchange.com/questions/249679/gravother... https://en.wikipedia.org/wiki/Baryon_acoustic_oscillations
Wait - If I throw a bowling ball really fast in a vacuum, does its temperature increase?
Yes. But if you take an existing slow ("cold") bowling ball in orbit around a mass concentration and hit it with a fast ("hot") one, it will be moving faster immediately. But now it's trajectory will take it out into a longer orbit where it slows down and spends more time moving near apogee, where it looks "cold".
So you end up with this paradoxical situation where a "hot" mass starts to interact with a "cold" one and ends up making it even colder, so it collapses.
So you end up with this paradoxical situation where a "hot" mass starts to interact with a "cold" one and ends up making it even colder, so it collapses.
I'm having trouble wrapping my head around how a measure with an absolute value (temperature) can relate to a measure with no absolute reference (velocity). In a purely inelastic collision, all the energy should be transfered to velocity, and thus the temperature not increase. A pure elastic collision would be the opposite. Similarly, if the ball and launcher are moving away relative to a given point, and the ball is launched towards that given point so that it is moving slower relatively, did the temperature increase or decrease? And with rotational velocity, if you double the radius the velocity halves because the total energy (and therefore temperature?) remains constant. Imagine if I used an inertialess drive to move faster - would my temperature have increased?
Temperature is a property of assemblies of particles, and in this case the “particles” are the bowling balls (dust, rocks), not necessarily atoms. Nothing in the formulation requires it to be atoms.
Of course then you get rocks sitting at a different internal temperature than the temperature of the overall cloud of rocks, and yes, over time that would reach an equilibrium. However, heat transfer in space, for large objects, is slow enough that this can be a very long time indeed.
Of course then you get rocks sitting at a different internal temperature than the temperature of the overall cloud of rocks, and yes, over time that would reach an equilibrium. However, heat transfer in space, for large objects, is slow enough that this can be a very long time indeed.
Thank you. I appreciate the explanation.
Gravothermal catastrophes make clusters bigger, in order to make stars the potential energy of gas clouds has to go down.
That's what I'm suggesting - the catastrophe proceeded to the point that all members of the cluster were either ejected (far away enough to be indiscernable relative to the quasar) or absorbed by the quasar core.
Thinking some more about it, there are probably some ways to constrain the amount of time it takes for a past runaway to have occurred that rules this explanation out.
Thinking some more about it, there are probably some ways to constrain the amount of time it takes for a past runaway to have occurred that rules this explanation out.
They sound like quasars that have consumed everything around them?
Once you look at the math, you realize that no matter how hard they try, black holes can’t suck everything around them.
It probably got kicked out of it's host galaxy during a merger.
These are quasars in 13+ billion years old footage.
Using the official age of the universe we need to then form the quasar in a dense matter region and then speedrun a galaxy merger that ejects the relevant quasar out into sparse space, all of that in a few hundred million years only.
Using contemporary cosmology practices I suggest we add a Dark Age to everything observed. Yes the age of the quasar is 13 billion something years in the axis of regular time, but due to observations disagreeing with this timeline we can just keep adding years to any given observation in the Dark Age, complex time axis, until the problem is solved
Using the official age of the universe we need to then form the quasar in a dense matter region and then speedrun a galaxy merger that ejects the relevant quasar out into sparse space, all of that in a few hundred million years only.
Using contemporary cosmology practices I suggest we add a Dark Age to everything observed. Yes the age of the quasar is 13 billion something years in the axis of regular time, but due to observations disagreeing with this timeline we can just keep adding years to any given observation in the Dark Age, complex time axis, until the problem is solved
Primordial black holes I believe are the answer to this, but I’m not a pro physicist.
AFAIK we have seen indirect evidence of their existence with Webb. They could explain some of this early structure.
AFAIK we have seen indirect evidence of their existence with Webb. They could explain some of this early structure.
Please respect the guidelines of this community. This is really unnecessary.
> Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.
> Comments should get more thoughtful and substantive, not less, as a topic gets more divisive.
> Please don't fulminate. Please don't sneer, including at the rest of the community.
> Be kind. Don't be snarky. Converse curiously; don't cross-examine. Edit out swipes.
> Comments should get more thoughtful and substantive, not less, as a topic gets more divisive.
> Please don't fulminate. Please don't sneer, including at the rest of the community.
Not sure how you read into any of those things in the parent comment. Dark Age he's suggesting already exists in cosmology in form of short period of rapid inflation that started and ended for no reason other than without it we can't fit inflationary cosmology to observation at all.
The GP poster is clearly making fun of dark matter and dark energy, supporting the typical trope among dark matter skeptics that both are mere crutches because most cosmologists refuse to find modifications to gravity for whatever reason. This interpretation is in line with other comments made in this thread by the same account (the one about "dark suction" and others).
Inflation has no influence on galaxy formation. Its duration was also a tiny fraction of a second, not years. It's also the first time I have heard it being associated with the term "dark age". The only actual "dark age" in cosmology in the common sense of the term is the period between reionization and first light by stars. Nothing to do with the quasars we are discussing here. It's really hard for me to read the comment in the way you suggest.
Inflation has no influence on galaxy formation. Its duration was also a tiny fraction of a second, not years. It's also the first time I have heard it being associated with the term "dark age". The only actual "dark age" in cosmology in the common sense of the term is the period between reionization and first light by stars. Nothing to do with the quasars we are discussing here. It's really hard for me to read the comment in the way you suggest.
Dark Matter is a name for set of observations that aren't explainable with currently accepted cosmological theory. There are many possible ideas of how Dark Matter problem can be solved. Why do you think making fun of specific idea of what might be the cause of Dark Matter problem or even the Dark Matter problem itself is problematic? Did suddenly the deficiencies of current state of science became not funny? Modifications to gravity are one of the possible solutions to Dark Matter problem (just as Machos and Wimps are) but not especially good or plausible ones and deserve being joked about just as much.
You can learn more about the problem from this physicist: https://www.youtube.com/watch?v=qS34oV-jv_A
> Inflation has no influence on galaxy formation.
That's completely not what I was talking about. I was saying that the era of rapid inflation that despite being postulated to be just a fraction of a second had immense impact on the shape of the universe can't be swept under the rug just because it's short and is already a kind of "Dark Time" when huge things were happening despite time barely passing.
You could equally sensibly postulate that 500 million years since the Big Bang there was a fraction of a second when galaxy formation underwent accelerated progress that aged them few billion years and that explains early black holes and such. Hopefully it won't come to that and more sensible explanation of what JWST sees will prevail.
It's true that "dark age" is not talked about in cosmology and is and invetion of the downvoted user. However when you think about it this naming analogy makes perfect sense when there seems to be missing mass it's called dark matter (which makes sense since it looks like the mass is there but it isn't shining), if there's missing energy it's called dark energy (despite the fact that we don't expect it to be shining in any way)... by extension when there's time missing we could call this problem dark time (witch is about as sensible name as dark energy) ... It's a case like scandal in Watergate hotel and then naming all scandals something-gate.
You can learn more about the problem from this physicist: https://www.youtube.com/watch?v=qS34oV-jv_A
> Inflation has no influence on galaxy formation.
That's completely not what I was talking about. I was saying that the era of rapid inflation that despite being postulated to be just a fraction of a second had immense impact on the shape of the universe can't be swept under the rug just because it's short and is already a kind of "Dark Time" when huge things were happening despite time barely passing.
You could equally sensibly postulate that 500 million years since the Big Bang there was a fraction of a second when galaxy formation underwent accelerated progress that aged them few billion years and that explains early black holes and such. Hopefully it won't come to that and more sensible explanation of what JWST sees will prevail.
It's true that "dark age" is not talked about in cosmology and is and invetion of the downvoted user. However when you think about it this naming analogy makes perfect sense when there seems to be missing mass it's called dark matter (which makes sense since it looks like the mass is there but it isn't shining), if there's missing energy it's called dark energy (despite the fact that we don't expect it to be shining in any way)... by extension when there's time missing we could call this problem dark time (witch is about as sensible name as dark energy) ... It's a case like scandal in Watergate hotel and then naming all scandals something-gate.
> Dark Matter is a name for set of observations
Angela collier's video is philosophically disingenuous (I do believe she believes what she says). You can't just lump a set of observations together and say it's not a hypothesis. The act of lumping those observations together implies the hypothesis that they share a casual unification.
"Observation" in the scientific vernacular carries added cachet because (barring fraud or miscalculation) it's irrefutable and more value neutral, versus a "hypothesis" which is designed to be refuted.
Calling the Dark Matter hypothesis an observation is a blatant attempt to inappropriately steal a sense of irrefutability. It's kind of terrifying that smart people are repeatedly using her video as a dunk
Angela collier's video is philosophically disingenuous (I do believe she believes what she says). You can't just lump a set of observations together and say it's not a hypothesis. The act of lumping those observations together implies the hypothesis that they share a casual unification.
"Observation" in the scientific vernacular carries added cachet because (barring fraud or miscalculation) it's irrefutable and more value neutral, versus a "hypothesis" which is designed to be refuted.
Calling the Dark Matter hypothesis an observation is a blatant attempt to inappropriately steal a sense of irrefutability. It's kind of terrifying that smart people are repeatedly using her video as a dunk
Steal?
Irrefutability?
That doesn't sound scientific at all. Especially in the context of hypothesis that supposedly accounts for a set of observations unexplainable by status quo, while having zero predictive power so far.
The only irrefutable thing is that we observe something that behaves like gravitational attraction from the spots in space that don't seem to emit electromagnetic radiation. "Why is that?" is the Dark Matter problem or question. Anything said beyond that question on this subject is a hypothesis of some form of solution to that question. All of them equally useless so far.
Irrefutability?
That doesn't sound scientific at all. Especially in the context of hypothesis that supposedly accounts for a set of observations unexplainable by status quo, while having zero predictive power so far.
The only irrefutable thing is that we observe something that behaves like gravitational attraction from the spots in space that don't seem to emit electromagnetic radiation. "Why is that?" is the Dark Matter problem or question. Anything said beyond that question on this subject is a hypothesis of some form of solution to that question. All of them equally useless so far.
> Steal?
> Irrefutability?
> That doesn't sound scientific at all
We're not talking about science here, we are talking about the philosophy of science.
At a trivial level it is still a hypothesis that each deviation from newtons laws (as in on a per galaxy basis) we observe has a common cause. But let's say that's quite trivial and it's an extremely easy hypothesis to accept.
There are levels to this. Are the deviations at the galaxy level caused by the same phenomenon as the deviations at the cluster level? Easy to believe, but still needs to be poked at. Slightly harder to believe out of hand than the previous
Is the ringing in the CMB caused by the same thing? If you don't admit that that is a harder sell (if even slightly) then that's dishonest.
By having grouped all of these distinct observations into one group of observations Angela has slyly implied they are all caused by the same thing, and introduced friction to exploring the possibility that they are not. That is scientifically irresponsible. Especially given, as you say, all the models suck.
> Irrefutability?
> That doesn't sound scientific at all
We're not talking about science here, we are talking about the philosophy of science.
At a trivial level it is still a hypothesis that each deviation from newtons laws (as in on a per galaxy basis) we observe has a common cause. But let's say that's quite trivial and it's an extremely easy hypothesis to accept.
There are levels to this. Are the deviations at the galaxy level caused by the same phenomenon as the deviations at the cluster level? Easy to believe, but still needs to be poked at. Slightly harder to believe out of hand than the previous
Is the ringing in the CMB caused by the same thing? If you don't admit that that is a harder sell (if even slightly) then that's dishonest.
By having grouped all of these distinct observations into one group of observations Angela has slyly implied they are all caused by the same thing, and introduced friction to exploring the possibility that they are not. That is scientifically irresponsible. Especially given, as you say, all the models suck.
> At a trivial level it is still a hypothesis that each deviation from newtons laws (as in on a per galaxy basis) we observe has a common cause. But let's say that's quite trivial and it's an extremely easy hypothesis to accept.
Even this isn't commonly accepted hypothesis that explains the problem named Dark Matter. MOND postulates that while most of the observed effects have the same cause, that gravity works differently, it also states that smaller effects observed might have another source.
She's lumping all those observations because they are lumped by most physicists because they might potentially have a single cause and thus might be parts of singular problem. Maybe at some point Dark Matter problem will have to be split into several but we are not at that point of knowledge yet.
Physicists have always searched for theories of everything and I haven't seen where the friction introduced by that search prevented them from finding out how parts like quantum mechanics or gravity work even if they don't have any underlying common mechanism. On the contrary, idea that vastly different phenonmenons might have a single cause led to deep advancements and insights like in the case of Newtonian gravity.
Philosophy is BS. It doesn't matter. What matters if there's data available. Until there is, everything is open to ridicule because all ideas are ridiculous until some of them are shown to be true. Then the next generation learns about them at schools, integrates them into their intuition and they no longer see how ridiculous they are.
Even this isn't commonly accepted hypothesis that explains the problem named Dark Matter. MOND postulates that while most of the observed effects have the same cause, that gravity works differently, it also states that smaller effects observed might have another source.
She's lumping all those observations because they are lumped by most physicists because they might potentially have a single cause and thus might be parts of singular problem. Maybe at some point Dark Matter problem will have to be split into several but we are not at that point of knowledge yet.
Physicists have always searched for theories of everything and I haven't seen where the friction introduced by that search prevented them from finding out how parts like quantum mechanics or gravity work even if they don't have any underlying common mechanism. On the contrary, idea that vastly different phenonmenons might have a single cause led to deep advancements and insights like in the case of Newtonian gravity.
Philosophy is BS. It doesn't matter. What matters if there's data available. Until there is, everything is open to ridicule because all ideas are ridiculous until some of them are shown to be true. Then the next generation learns about them at schools, integrates them into their intuition and they no longer see how ridiculous they are.
I was not sure about the GP comment, but "complex time axis" near the end and other two similar comments make it look like a bad comment.
I was just watching this: https://www.youtube.com/watch?v=c1sZpSoMq5g
And, apparently, poor lonely black holes can evaporate over time?
And, apparently, poor lonely black holes can evaporate over time?
Bekenstein-Hawking radiation is unproven hypothesis based on Bekenstein‘s idea that black hole should have entropy and non-zero temperature. It does not follow from General Relativity equations. One can argue just as well that black holes have zero temperature and do not evaporate.
Not if their Hawking temperature is below the CMB, which is the case I think for any above asteroid mass. As the universe cools and the CMB drops that threshold drops. The big black holes will last n^n^n… ridiculous amounts of time.
Just one ^n. Supermassive black holes are expected to have completely evaporated by 10^100 years.
Evaporate into what? Nothingness?
Energy, over a very long period of time. Remember that mass and energy are equivalent.
Hawking temperature is inversely proportional to black hole size, so the bigger the hole the "colder" it is. The largest black holes will start evaporating very slowly once the CMB drops below their temperature.
A tiny micro black hole, if one were created, would evaporate almost instantly converting 100% of its mass into energy, basically a bomb. E.g. a 1kg micro black hole smaller than an electron would have a yield similar to a small hydrogen bomb, most of which would be released as ultra high energy gamma rays.
Black holes are awesome. In some ways they are the most extreme things in the universe, the extreme-est of extreme physics.
The mass-energy density required to create them is so far beyond anything humanly possible that trying to do so with, for example, hydrogen bombs would be not much better than trying to do it by squeezing really hard with your hand. It requires things like the first few milliseconds after the Big Bang (if primordial black holes exist) or collapsing massive stars. To give a sense of this density: a black hole with the mass of the Earth would be about the size of a marble (Schwartzchild radius). Inside of course there's either a true singularity or -- if certain theories of quantum gravity are correct -- a region of some kind of maximum-theoretical-density matter. (Some theories predict that true singularities don't exist.)
If somehow someday it were possible to create or control them, it would be possible to access energies far beyond fusion or even antimatter-driven reactions... think perfect direct mass-energy conversion with near 100% efficiency.
Hawking temperature is inversely proportional to black hole size, so the bigger the hole the "colder" it is. The largest black holes will start evaporating very slowly once the CMB drops below their temperature.
A tiny micro black hole, if one were created, would evaporate almost instantly converting 100% of its mass into energy, basically a bomb. E.g. a 1kg micro black hole smaller than an electron would have a yield similar to a small hydrogen bomb, most of which would be released as ultra high energy gamma rays.
Black holes are awesome. In some ways they are the most extreme things in the universe, the extreme-est of extreme physics.
The mass-energy density required to create them is so far beyond anything humanly possible that trying to do so with, for example, hydrogen bombs would be not much better than trying to do it by squeezing really hard with your hand. It requires things like the first few milliseconds after the Big Bang (if primordial black holes exist) or collapsing massive stars. To give a sense of this density: a black hole with the mass of the Earth would be about the size of a marble (Schwartzchild radius). Inside of course there's either a true singularity or -- if certain theories of quantum gravity are correct -- a region of some kind of maximum-theoretical-density matter. (Some theories predict that true singularities don't exist.)
If somehow someday it were possible to create or control them, it would be possible to access energies far beyond fusion or even antimatter-driven reactions... think perfect direct mass-energy conversion with near 100% efficiency.
Thanks for the in depth answer. Pretty wild that something that nothing can escape, not even light, can still just evaporate over ridiculous time spans.
We think this is the case, and the math very much says that it is, but in truth we have yet to observe it so we cannot be absolutely 100% certain. If it's not the case it would mean new physics. It happens due to quantum effects at the event horizon.
Photons.
Is that necessarily true in the earliest moments of the universe? Probably there are good reasons for it to be so that I don't understand, but then most of what cosmologists understand about the period that JWST looks back to is from extrapolating backwards, and it seems like the new observations it has enabled keep disagreeing with previous assumptions. Anyway, I really look forward to finding out what improvements to theory can be made to better explain anomalies like these lonely quasars or the apparently overdeveloped young galaxies.
If they did they’d be invisible, which is why isolated primordial black holes with a variety of masses are a dark matter candidate. A quasar would be one with a giant accretion disk right?
Maybe a theory of hard-to-observe Dark Suction will come to the rescue
Quasars are bright because they are surrounded by material that accretes and shines. If they are isolated then they are just quiet black holes.
Well, the accretion disk surely runs out at some point, and just before that point, shouldn't it look like a quasar in surprisingly empty space?
The brightness comes from the accretion disk.
Quasars don't and can't even consume a significant fraction of their host galaxies' mass, never mind other nearby galaxies.
If Halton Arp were still here he'd be smiling
This is clickbait / regurgitating a press release from a university outfit
tl;dr there's a lot of dust around the quasar
Astronomy has a big problem with people overhyping their results
tl;dr there's a lot of dust around the quasar
Astronomy has a big problem with people overhyping their results
benjamaan(1)
haccount(3)
first brown dwarfs seen in other galaxies too
https://bsky.app/profile/philplait.bsky.social/post/3l7bssmh...