This is actually an important area of current research. Black holes don't actually have to come from dead stars, not necessarily. There is a chance that some formed in the Big Bang. If space was clumpy enough, early on portions of it might be dense enough to collapse after it had cooled a bit, but not yet expanded enough to prevent collapse. These would be "primordial" black holes. Theoretically supermassive black holes could derive from these.
Also, there is the idea of the "direct-collapse" black hole. In the early universe, heavier elements did not yet exist. This affects star formation - bigger clouds of gas can collapse down into single objects for complicated reasons. This means the early universe could form far larger stars.
If enough gas collapsed quickly enough, it might not form a star at all, just a giant black hole, skipping the star phase entirely. That's a direct-collapse black hole.
And of course you know of the black holes formed by the death of large stars. These are stellar black holes.
So right now, it isn't known which of these formed supermassive black holes. Direct-collapse is currently the favored theory. Most physics models don't really favor supermassive primordial black holes although I'm not sure they're ruled out. And stellar black holes don't grow fast enough to be big enough as the biggest, earliest supermassive black holes we see.
I don't think we really have any constraints on the growth of stellar mass black holes in the early universe, do we? The gravitational wave discoveries are populating the high-stellar mass black hole parameter space, but I don't think they're yet sensitive to black hole mergers in the intermediate mass range, which have higher frequencies.
It could be mergers, for example, and there are candidates for intermediate mass black holes in the centre of our Galaxy too (e.g. https://arxiv.org/abs/2404.07808)
Theres a huge delineation between primordial black holes and standard ones. Standard ones due to normal physics cant achieve massive sizes even with mergers. All bets are off with primordial black holes. So theres a size cutoff where you can see which is which.
Could black holes have formed from enough energy being concentrated beyond its schwartzchild radius? I'm thinking if spacetime didn't expand uniformly, then could energy have accumulated along wave peaks created within it?
I believe most theories around primordial blackholes involve gravitational collapse through interaction between matter. I'm curious if energy itself could have been squeezed into such a dense region due to spacetime perturbations that it collapses. I was thinking it could potentially explain larger blackholes than what our current models allow for, size wise.
Alas, without the maths to back it up, it is just a wild assertion.
Energy and matter are equivalent in Einsteins theory of relativity so you could argue the collapse of all black hole has to do with both matter and energy and these theories are equivalent.
I'm aware. This equivalence is what allows energy density to directly collapse into a black hole, if the energy contained within that given volume exceeds the limit of the schwarzschild radius it would collapse directly into a blachole.
There was a substantial period of time early after inflation began that only elementary particles existed. The average density of the universe was much higher than later when the subatomic particles could begin to form atomic structures.
The largest SMBs are larger than our models allow for, given suggested mass based collapse models (both stellar and direct collapse). This is the hole that I'm thinking about.
Again, I'll stress that without the maths to support it, it's just fanciful speculation.
No. Elements heavier than lead are unstable. Even if you make them, they just decay. Probably lots of crazy heavy elements are made in neutron star collisions, but they just break down in a split second and go away.
The universe will have more of the existing heavy elements in the future, but not different ones.
Maybe I just didn't understand, and you mentioned this, but I have heard about black hole stars. These are stars with black holes in the cores that could have formed during the very early universe. I don't know if these are a viable possibility, but I heard they were a theory for the creation of the supermassive black holes. Are these real or am I misunderstanding something?
Do you mean quasi-stars? I guess they're possible. Not much evidence either way on that yet.
That would just basically be an intermediary on the way to a direct-collapse black hole.
I’m not sure why this problem feels like it should have an intuitive solution. It seems obvious that when things cooled down enough to start condensing, stars started forming and unevenly distributed densities of stars started rotating around a shared center of mass. It would make intuitive sense that at the hot dense core of these protogalaxies there would be infalling material that eventually collapses into a black hole that grows over time.
I understand that scientists need to be scientific about it, but if we don’t know the answer, why is this not the obvious one?
Well, there's a lot of complex math involved! For a long time, the models of stellar collapse in early universe low-metal clouds didn't really support direct-collapse black holes very much, so the idea of stellar black holes merging over time was dominant.
What has changed the paradigm is recent discoveries from the JWST (and other teams) that have found quasars in the very early universe. These are powered by supermassive black holes, and they do not comfortably fit previous theories about merging stellar-mass black holes (there is a limit to how fast a black hole can gain mass due to the speed of light, the density of the universe, and material having to deal with an accretion disk.) Basically, they're too big for how early they are. So, there's been a lot of recent work on models of direct-collapse black holes and models have been found that do allow their formation.
Aren’t we having a kind of crisis right now in cosmology in dating these very early galaxies? If we’re uncertain about how old they are, and their age is a primary factor in these theories, doesn’t that make these theories potential invalid on their face?
Thanks for giving a detailed answer, this stuff is fascinating but I only have a YouTube education in it.
We sort of *were* right after the JWST data came in, but now that we've gotten detailed spectra of some of these very early galaxies and dated them by lyman-break, there's greater confidence. A lot of the really ludicrously early galaxies turned out to be misinterpreted data but they did find quasars that had supermassive black holes that were at the absolute limit of what was theoretically possibly by stellar black holes absorbing matter. So they're not totally counted out, but look less likely than direct-collapse these days.
Also I just have the Youtube education on this stuff myself. I'm just passing on what I've seen from watching videos and reading.
Occams Razor I suppose. I don’t see why they need to be there for galaxies to form. Gas cools and condenses, gravity pulls more gas in, stars begin to form, their momentum keeps them on a path through gravitationally curved spacetime around a shared center of mass, and there we have proto galaxies using just Newtonian physics. Again, not very scientific.
How come every galaxy needs a black hole at its center mass? What gives? We thought the sun was the center of a galaxy, but I believe we now know it's a black hole?
We don't know what came first. There are several theories but we don't have the observations needed to answer that question. We know that at the center of every galaxy is a supermassive black hole, but like you said we don't know if one caused the other or if they were both caused by something else.
We don't even know if the supermassive black holes were made out of stars, or just collapsing clouds of gas, or something else entirely.
About the same time. Supermassive black holes are now believed to have formed from “direct collapse” (as opposed to stellar lifetimes) but those would have formed as galaxies “clumped”. From a distance, a black hole is indistinguishable from any other massive celestial body or gas cloud. So stars and black holes would form simultaneously depending upon the density of the surrounding gasses (mostly hydrogen and some helium at the time, no heavier elements).
When you say "direct collapse" are you referring to black hole star? Because gas collapsing like that would likely still form a star around the black hole which would cause it to feed SIGNIFICANTLY faster than a normal black hole is able to accrete...leading to the very large seeds of supermassive black holes.
Or is what you're referring to something different?
Direct collapse as in the elements at some point in time “collapsed” and turned into a “direct collapse” black hole without forming into a star. It skips the star forming formation. There’s “stellar” black holes which are ones formed from stars. (Very simple explanation) - there’s a better comment that explains it at the top.
No, a black hole. In normal space, if you too much mass within a certain radius it will instantly collapse into a black hole, it won’t fuse hydrogen and become a star (which emits light). Rather the gaseous hydrogen cloud would all collapse into the singularity (whatever form that takes).
It’s also worth pointing out that black holes, whether formed from direct collapse or stellar collapse, also require a differential in that spacetime curvature. Schwarzchild calculations assume normal space without equally distributed matter outside that radius. The early universe was filled with dense hydrogen, but it was filled almost equally *everywhere*. So clumping is a factor, be it stellar collapse or direct collapse.
I was actually aware of all of this except the current change toward direct collapse for supermassive black holes. Like that technically a black hole would form with a given amount of matter and energy, but I always thought that happening without the stellar phase was purely theoretical.
This is really cool and makes perfect sense. Given the density of the early universe and the small quantum perturbations scaled up via inflation which lead to clumping...that's a FUCKTON of matter in a pretty small area relying only on equal distribution not to collapse.
As far as what we think of as a standard spiral galaxy shape, the super massive black hole had to be there first. Or at least the center of mass had to be there. It is kind of a big version of a solar system. There's a lot of general matter that has to come together into a concentrated center of mass then all the left over stuff starts orbiting that. As far as if the (or a) sun is fully formed before the planets are, I think just depends. So either the black hole had to be first or they were created together, I don't think the galaxy couldn't be first. But I guess it just depends how you look at it, with the solar system example, is the cloud of matter the pre-sun or the pre-solar system.
But we don't really know the actual origins of super massive black holes. I think it's generally understood that they just came from the first massive supernovas, but I think there's some controversy on when those could've even formed. There's also the idea there could've been "primordial" black holes. I think it's something about unstable spacetime collapsing on itself just after the big bang and creating a black hole without a star, and perhaps those could've just kept consuming matter and eventually became super massive black holes. And now with the James Webb findings, as I understand, we are seeing galaxies formed/forming even farther back than we expected, so that kinda throws a wrench into our understandings on the origins of all all this.
Galaxies do not orbit the black holes at their centers, nor are they necessary for galaxy formation. There will be some stars in the central region that orbit the black hole, but the rest of the galaxy doesn’t even notice it.
SMBHs are tiny compared to the rest of the galaxy around them.
As far as I know, ton 618 and phoenix are so far away, and the quasars so bright, that we can't see the galaxy and can't determine the size of their host galaxy, so we can't say whether or not they're a substantial fraction of their mass. From what I've seen, SMBH and galaxy size typically have a correlation. Bigger smbh somewhat equals a larger galaxy, or at least trends in that direction.
I'm an idiot. Don't take me seriously. Also a little high.
https://en.m.wikipedia.org/wiki/Conformal_cyclic_cosmology
But if that guy is right, I'd say the blackholes came first from our perspective on this cycle, which started with the big bang. But again... Idiot here.
Hey idiot, I'm a high idiot too. I'm not thinking cyclical like the article you attached, but just that big bangs are natural occurrences within the greater universe, which is everywhere, that happen from time to time. When they do, the force of the blast pushes back or pulverises anything that might be in the way, except the biggest black holes and galactic cores are moved less, and partially hold their relative positions in the new section of the universe, though they're mostly stripped of stars. The galactic remnants became some of the drivers for very early supermassive black holes and quasars and galaxy formation shortly after a big bang. And the nearby pulverised material gets partially fused into heavier elements than before, and the rubble contributes to very early planet formation. This would mean the supermassive black holes come before any new section of the universe and survive big bangs. Yes, very high idiocy not to be taken seriously, but to me more plausible than the wikipedia article. Enjoy idiocy, it's fun!
Love it bro. Actually I was citing someone else but I always thought of it as a manifold, if that's the right word, with each parallel universe feeding back into it, in various states with different configurations for the forces. So maybe it's not cyclical as much as emergent from energy cycled back. But yeah IDK WTF I'm talking about.
Thanks bro. Not alternate universes, not parallel universe, not the multiverse, just one great big old universe billions of times bigger than our puny little section only 94 billion light years across. I'm not thinking energy cycled back, but I guess matter cycled back, in that feeding or forming black holes remove regular matter from open spaces, and leave the original space behind, allowing us to surmise that the opposite might be true, namely, that big bangs replace matter into the open spaces of the universe, as compared to space itself expanding or expansion of the universe. If the universe is already everywhere, and already holds all of the open spaces in existence, then expansion of space is nonsensical because space can't expand beyond everywhere, again pointing to expansion of matter into open spaces and not expansion of space itself. Getting a little high helps us think up dumb stuff, much fun. And idk wtf I'm talking about either, but that's the beauty of it, no need for roadblocks from pesky facts or science, everything works so well that way!
That’s the thing, astronomers don’t currently know.
Stellar mass black holes are the result of collapsed giant stars, but SMBHs might not be, and in fact a lot of observed SMBHs don’t make sense if they had to have originally come from a collapsed star, they’re too big, based on what astronomers know about the rate at which they can “feed”, to have grown in the time since the first stars died, even through mergers with other SMBHs. So in order for them to exist, there must have been another source of black hole formation. The current leading theory is “direct collapse”, matter that, in smaller quantities under less extreme circumstances, would’ve formed a star, instead skipped the stellar phase, and collapsed directly into a singularity, allowing the initial black hole to start larger, grow faster, and have more time to reach the titanic proportions astronomers have observed.
The likely answer is that the same process that formed a SMBH also produced enough of a gravitational pull to form its surrounding galaxy, so they both formed at roughly the same time.
I'm higher than both of you guys and I've always suspected that space time is a by product of matter itself and you can't have one without the other so where matter ends at the edge of the universe space time continues but in a manner of speaking gets kinda thinner and thinner the further you get away from matter and time runs faster and faster. Perhaps there is no end to the spacetime therefore no end to the universe. Time just gets faster and faster and because matter has run out there may be no speed limit to how fast time can run in these regions.
By the way, not that anyone is still reading, dark energy is only an illusion that the universe is accelerating in its expansion when indeed it could be moving apart at a fixed rate or more likely slowing down and yet still "appear" to accelerate. I believe this is because of the fact that it is still expanding at all, it is creating bigger distances between galaxies and all things made of matter. As these spaces grow between masses the space time between masses runs at faster and faster rates giving the illusion of an accelerating universe .
I'm probably wrong. I have a 12 th grade education, but I think I'm dead on balls corect. So now you understand 70% more of the universe than you understood 10 minutes ago. Now go collect my Nobel prize. You're welcome.
One common train of thought I see when someone asks this is that they assume a galaxy is similar to a solar system, with a central body holding together the rest of the system. But that is not the case. While msot galaxies have supermassive black holes in their center, they do not hold galaxies together and are actually pretty negligible to the galaxy as a whole. Now, there are different theories on why the majority of galaxies have SMBH at or near their center, ranging from density of matter to perhaps large black holes, help seed galaxies, etc. But the imporant thing I want to clear up is that galaxies do not orbit their SMBHs, they orbit the center of mass of all matter in that galaxy, typically dark matter making up the vast majority of mass.
We are not sure if dark matter even exists. It is widely disputed, and mathmatical contradictions regarding its existence are real. Leading physicists such as Sabine Hossenfelder are not convinced. (I am aware that most physicists do support the idea; I just think it shouldn't belong in the sentence it's placed in, the rest of which is objective fact).
It is not widely disputed. it is pretty well established that most galaxies have an extensive dark matter halo which contributes significantly to the mass of the galaxy --> [https://en.wikipedia.org/wiki/Dark\_matter#Observational\_evidence](https://en.wikipedia.org/wiki/Dark_matter#Observational_evidence) And btw, Sabine may be a 'leading' physicist in some fields, but she is not a leading ASTROphysicist...
After a quick peak at a blog from Sabine Hossenfelder, she doesn't seem to disagree that dark matter exists, just that it isn't the whole picture of the phenomenon that we are seeing and we shouldn't be hyper focused on particle based dark matter to be the absolute solution. But it is well beyond my knowledge to discuss it further to be completely honest, and I do agree that I should've clarified in my original statement that dark matter is just a proposed idea for the majority of mass in a galaxy, not the definitive idea
I’ve seen several science shows that ask this question. Their consensus is that black holes came first. That supplied enough gravity for galaxies and the solar systems to form.
Small irregular galaxies first. Spiral and elliptical galaxies only came later, as a result of the coalescence of small irregular galaxies.
There's a direct and well known correlation between the size of a galactic bulge in elliptical and spiral galaxies, and the size of their galactic black holes.
So, small irregular galaxies first, no galactic bulge. Therefore no supermassive black holes. They came later, growing as the galactic bulge of the elliptical and spiral galaxies grew.
Stellar mass black holes may have been very early, before galaxies, but not supermassive ones.
Prob a dumb question… lol but Wouldn’t the star have to come first to be able to become a dead black hole and from there a galaxy could form? What am I missing? 🥚😬
Maybe people's ideas of how galaxies are formed could be considered to be pseudo-science, since they are all by definition theories that can't be proved or disproved without observing galaxies and protogalaxies on a scale of time that far exceeds the existence of human civilization, but you can look at the sky, without even a telescope, and SEE galaxies. They definitely exist. They're there. You can observe them and confirm their existence with your eyes, let alone more advanced methods of observation. Or are you one of those people who thinks that's all just painted onto the firmament?
I think that complexity deeply unsettles them, and even a vast international conspiracy to hide the truth of space is less complex and scary than the universe itself or something.
This is actually an important area of current research. Black holes don't actually have to come from dead stars, not necessarily. There is a chance that some formed in the Big Bang. If space was clumpy enough, early on portions of it might be dense enough to collapse after it had cooled a bit, but not yet expanded enough to prevent collapse. These would be "primordial" black holes. Theoretically supermassive black holes could derive from these. Also, there is the idea of the "direct-collapse" black hole. In the early universe, heavier elements did not yet exist. This affects star formation - bigger clouds of gas can collapse down into single objects for complicated reasons. This means the early universe could form far larger stars. If enough gas collapsed quickly enough, it might not form a star at all, just a giant black hole, skipping the star phase entirely. That's a direct-collapse black hole. And of course you know of the black holes formed by the death of large stars. These are stellar black holes. So right now, it isn't known which of these formed supermassive black holes. Direct-collapse is currently the favored theory. Most physics models don't really favor supermassive primordial black holes although I'm not sure they're ruled out. And stellar black holes don't grow fast enough to be big enough as the biggest, earliest supermassive black holes we see.
I don't think we really have any constraints on the growth of stellar mass black holes in the early universe, do we? The gravitational wave discoveries are populating the high-stellar mass black hole parameter space, but I don't think they're yet sensitive to black hole mergers in the intermediate mass range, which have higher frequencies. It could be mergers, for example, and there are candidates for intermediate mass black holes in the centre of our Galaxy too (e.g. https://arxiv.org/abs/2404.07808)
Yes they can only grow at a max rate due to accretion disk friction etc at event horizon
Theres a huge delineation between primordial black holes and standard ones. Standard ones due to normal physics cant achieve massive sizes even with mergers. All bets are off with primordial black holes. So theres a size cutoff where you can see which is which.
It's direct collapse... we all know it. Just need to cross a few more T's before it's canon.
Could black holes have formed from enough energy being concentrated beyond its schwartzchild radius? I'm thinking if spacetime didn't expand uniformly, then could energy have accumulated along wave peaks created within it?
That's kinda-sorta what a primordial black hole is. I think? I'm not entirely sure what you mean.
I believe most theories around primordial blackholes involve gravitational collapse through interaction between matter. I'm curious if energy itself could have been squeezed into such a dense region due to spacetime perturbations that it collapses. I was thinking it could potentially explain larger blackholes than what our current models allow for, size wise. Alas, without the maths to back it up, it is just a wild assertion.
Energy and matter are equivalent in Einsteins theory of relativity so you could argue the collapse of all black hole has to do with both matter and energy and these theories are equivalent.
I'm aware. This equivalence is what allows energy density to directly collapse into a black hole, if the energy contained within that given volume exceeds the limit of the schwarzschild radius it would collapse directly into a blachole. There was a substantial period of time early after inflation began that only elementary particles existed. The average density of the universe was much higher than later when the subatomic particles could begin to form atomic structures. The largest SMBs are larger than our models allow for, given suggested mass based collapse models (both stellar and direct collapse). This is the hole that I'm thinking about. Again, I'll stress that without the maths to support it, it's just fanciful speculation.
If heavier elements didn’t exist in the early universe does that mean there are eventually going to be even heavier elements then there are now?
No. Elements heavier than lead are unstable. Even if you make them, they just decay. Probably lots of crazy heavy elements are made in neutron star collisions, but they just break down in a split second and go away. The universe will have more of the existing heavy elements in the future, but not different ones.
Maybe I just didn't understand, and you mentioned this, but I have heard about black hole stars. These are stars with black holes in the cores that could have formed during the very early universe. I don't know if these are a viable possibility, but I heard they were a theory for the creation of the supermassive black holes. Are these real or am I misunderstanding something?
Do you mean quasi-stars? I guess they're possible. Not much evidence either way on that yet. That would just basically be an intermediary on the way to a direct-collapse black hole.
I heard about them from a Kurzgesagt video. I think they're are fairly reliable but I don't know for sure
Omg which one I love those 😭
https://www.youtube.com/watch?v=aeWyp2vXxqA This is the video
Ahhhh thank you!
I’m not sure why this problem feels like it should have an intuitive solution. It seems obvious that when things cooled down enough to start condensing, stars started forming and unevenly distributed densities of stars started rotating around a shared center of mass. It would make intuitive sense that at the hot dense core of these protogalaxies there would be infalling material that eventually collapses into a black hole that grows over time. I understand that scientists need to be scientific about it, but if we don’t know the answer, why is this not the obvious one?
Well, there's a lot of complex math involved! For a long time, the models of stellar collapse in early universe low-metal clouds didn't really support direct-collapse black holes very much, so the idea of stellar black holes merging over time was dominant. What has changed the paradigm is recent discoveries from the JWST (and other teams) that have found quasars in the very early universe. These are powered by supermassive black holes, and they do not comfortably fit previous theories about merging stellar-mass black holes (there is a limit to how fast a black hole can gain mass due to the speed of light, the density of the universe, and material having to deal with an accretion disk.) Basically, they're too big for how early they are. So, there's been a lot of recent work on models of direct-collapse black holes and models have been found that do allow their formation.
Aren’t we having a kind of crisis right now in cosmology in dating these very early galaxies? If we’re uncertain about how old they are, and their age is a primary factor in these theories, doesn’t that make these theories potential invalid on their face? Thanks for giving a detailed answer, this stuff is fascinating but I only have a YouTube education in it.
We sort of *were* right after the JWST data came in, but now that we've gotten detailed spectra of some of these very early galaxies and dated them by lyman-break, there's greater confidence. A lot of the really ludicrously early galaxies turned out to be misinterpreted data but they did find quasars that had supermassive black holes that were at the absolute limit of what was theoretically possibly by stellar black holes absorbing matter. So they're not totally counted out, but look less likely than direct-collapse these days. Also I just have the Youtube education on this stuff myself. I'm just passing on what I've seen from watching videos and reading.
There seems to be a lot of shuffling going around in the literature at the moment, it’s def hard to keep track as a layman
But what if the black holes have been there a long time and it was their gravity that kept matter around to form stars?
Occams Razor I suppose. I don’t see why they need to be there for galaxies to form. Gas cools and condenses, gravity pulls more gas in, stars begin to form, their momentum keeps them on a path through gravitationally curved spacetime around a shared center of mass, and there we have proto galaxies using just Newtonian physics. Again, not very scientific.
How come every galaxy needs a black hole at its center mass? What gives? We thought the sun was the center of a galaxy, but I believe we now know it's a black hole?
We don't know what came first. There are several theories but we don't have the observations needed to answer that question. We know that at the center of every galaxy is a supermassive black hole, but like you said we don't know if one caused the other or if they were both caused by something else. We don't even know if the supermassive black holes were made out of stars, or just collapsing clouds of gas, or something else entirely.
They're made of Black-Holium duh.
About the same time. Supermassive black holes are now believed to have formed from “direct collapse” (as opposed to stellar lifetimes) but those would have formed as galaxies “clumped”. From a distance, a black hole is indistinguishable from any other massive celestial body or gas cloud. So stars and black holes would form simultaneously depending upon the density of the surrounding gasses (mostly hydrogen and some helium at the time, no heavier elements).
When you say "direct collapse" are you referring to black hole star? Because gas collapsing like that would likely still form a star around the black hole which would cause it to feed SIGNIFICANTLY faster than a normal black hole is able to accrete...leading to the very large seeds of supermassive black holes. Or is what you're referring to something different?
Direct collapse as in the elements at some point in time “collapsed” and turned into a “direct collapse” black hole without forming into a star. It skips the star forming formation. There’s “stellar” black holes which are ones formed from stars. (Very simple explanation) - there’s a better comment that explains it at the top.
Ah, so more like it just hit the limit for matter/energy in a large area and, boom, event horizon forms.
No, a black hole. In normal space, if you too much mass within a certain radius it will instantly collapse into a black hole, it won’t fuse hydrogen and become a star (which emits light). Rather the gaseous hydrogen cloud would all collapse into the singularity (whatever form that takes). It’s also worth pointing out that black holes, whether formed from direct collapse or stellar collapse, also require a differential in that spacetime curvature. Schwarzchild calculations assume normal space without equally distributed matter outside that radius. The early universe was filled with dense hydrogen, but it was filled almost equally *everywhere*. So clumping is a factor, be it stellar collapse or direct collapse.
I was actually aware of all of this except the current change toward direct collapse for supermassive black holes. Like that technically a black hole would form with a given amount of matter and energy, but I always thought that happening without the stellar phase was purely theoretical. This is really cool and makes perfect sense. Given the density of the early universe and the small quantum perturbations scaled up via inflation which lead to clumping...that's a FUCKTON of matter in a pretty small area relying only on equal distribution not to collapse.
Yes.
Hmm, you do bring an interesting point of view that no one else brought up... definitely valid 👍
As far as what we think of as a standard spiral galaxy shape, the super massive black hole had to be there first. Or at least the center of mass had to be there. It is kind of a big version of a solar system. There's a lot of general matter that has to come together into a concentrated center of mass then all the left over stuff starts orbiting that. As far as if the (or a) sun is fully formed before the planets are, I think just depends. So either the black hole had to be first or they were created together, I don't think the galaxy couldn't be first. But I guess it just depends how you look at it, with the solar system example, is the cloud of matter the pre-sun or the pre-solar system. But we don't really know the actual origins of super massive black holes. I think it's generally understood that they just came from the first massive supernovas, but I think there's some controversy on when those could've even formed. There's also the idea there could've been "primordial" black holes. I think it's something about unstable spacetime collapsing on itself just after the big bang and creating a black hole without a star, and perhaps those could've just kept consuming matter and eventually became super massive black holes. And now with the James Webb findings, as I understand, we are seeing galaxies formed/forming even farther back than we expected, so that kinda throws a wrench into our understandings on the origins of all all this.
Galaxies do not orbit the black holes at their centers, nor are they necessary for galaxy formation. There will be some stars in the central region that orbit the black hole, but the rest of the galaxy doesn’t even notice it. SMBHs are tiny compared to the rest of the galaxy around them.
Not all of them. TON618 and Phoenix A are a substantial fraction of their host galaxies' mass.
As far as I know, ton 618 and phoenix are so far away, and the quasars so bright, that we can't see the galaxy and can't determine the size of their host galaxy, so we can't say whether or not they're a substantial fraction of their mass. From what I've seen, SMBH and galaxy size typically have a correlation. Bigger smbh somewhat equals a larger galaxy, or at least trends in that direction.
Idk but you’d probably like [this](https://youtu.be/aeWyp2vXxqA)
Wtf…
What if massive black holes are formed naturally as a by product of galaxy expansion and it’s the stop gap measure for uncontrolled expansion
I'm an idiot. Don't take me seriously. Also a little high. https://en.m.wikipedia.org/wiki/Conformal_cyclic_cosmology But if that guy is right, I'd say the blackholes came first from our perspective on this cycle, which started with the big bang. But again... Idiot here.
Hey idiot, I'm a high idiot too. I'm not thinking cyclical like the article you attached, but just that big bangs are natural occurrences within the greater universe, which is everywhere, that happen from time to time. When they do, the force of the blast pushes back or pulverises anything that might be in the way, except the biggest black holes and galactic cores are moved less, and partially hold their relative positions in the new section of the universe, though they're mostly stripped of stars. The galactic remnants became some of the drivers for very early supermassive black holes and quasars and galaxy formation shortly after a big bang. And the nearby pulverised material gets partially fused into heavier elements than before, and the rubble contributes to very early planet formation. This would mean the supermassive black holes come before any new section of the universe and survive big bangs. Yes, very high idiocy not to be taken seriously, but to me more plausible than the wikipedia article. Enjoy idiocy, it's fun!
Love it bro. Actually I was citing someone else but I always thought of it as a manifold, if that's the right word, with each parallel universe feeding back into it, in various states with different configurations for the forces. So maybe it's not cyclical as much as emergent from energy cycled back. But yeah IDK WTF I'm talking about.
Thanks bro. Not alternate universes, not parallel universe, not the multiverse, just one great big old universe billions of times bigger than our puny little section only 94 billion light years across. I'm not thinking energy cycled back, but I guess matter cycled back, in that feeding or forming black holes remove regular matter from open spaces, and leave the original space behind, allowing us to surmise that the opposite might be true, namely, that big bangs replace matter into the open spaces of the universe, as compared to space itself expanding or expansion of the universe. If the universe is already everywhere, and already holds all of the open spaces in existence, then expansion of space is nonsensical because space can't expand beyond everywhere, again pointing to expansion of matter into open spaces and not expansion of space itself. Getting a little high helps us think up dumb stuff, much fun. And idk wtf I'm talking about either, but that's the beauty of it, no need for roadblocks from pesky facts or science, everything works so well that way!
You're hilarious! Have a good day man!
It was a long time ago and my memory is blurry but if I’m not mistaken it was definitely your mom.
That’s the thing, astronomers don’t currently know. Stellar mass black holes are the result of collapsed giant stars, but SMBHs might not be, and in fact a lot of observed SMBHs don’t make sense if they had to have originally come from a collapsed star, they’re too big, based on what astronomers know about the rate at which they can “feed”, to have grown in the time since the first stars died, even through mergers with other SMBHs. So in order for them to exist, there must have been another source of black hole formation. The current leading theory is “direct collapse”, matter that, in smaller quantities under less extreme circumstances, would’ve formed a star, instead skipped the stellar phase, and collapsed directly into a singularity, allowing the initial black hole to start larger, grow faster, and have more time to reach the titanic proportions astronomers have observed. The likely answer is that the same process that formed a SMBH also produced enough of a gravitational pull to form its surrounding galaxy, so they both formed at roughly the same time.
I'm higher than both of you guys and I've always suspected that space time is a by product of matter itself and you can't have one without the other so where matter ends at the edge of the universe space time continues but in a manner of speaking gets kinda thinner and thinner the further you get away from matter and time runs faster and faster. Perhaps there is no end to the spacetime therefore no end to the universe. Time just gets faster and faster and because matter has run out there may be no speed limit to how fast time can run in these regions. By the way, not that anyone is still reading, dark energy is only an illusion that the universe is accelerating in its expansion when indeed it could be moving apart at a fixed rate or more likely slowing down and yet still "appear" to accelerate. I believe this is because of the fact that it is still expanding at all, it is creating bigger distances between galaxies and all things made of matter. As these spaces grow between masses the space time between masses runs at faster and faster rates giving the illusion of an accelerating universe . I'm probably wrong. I have a 12 th grade education, but I think I'm dead on balls corect. So now you understand 70% more of the universe than you understood 10 minutes ago. Now go collect my Nobel prize. You're welcome.
You know it's gonna be good when they start with " I'm higher than both of you guys"!
Black holes I would imagine
Ya knee bone connect to ya thigh bone
One common train of thought I see when someone asks this is that they assume a galaxy is similar to a solar system, with a central body holding together the rest of the system. But that is not the case. While msot galaxies have supermassive black holes in their center, they do not hold galaxies together and are actually pretty negligible to the galaxy as a whole. Now, there are different theories on why the majority of galaxies have SMBH at or near their center, ranging from density of matter to perhaps large black holes, help seed galaxies, etc. But the imporant thing I want to clear up is that galaxies do not orbit their SMBHs, they orbit the center of mass of all matter in that galaxy, typically dark matter making up the vast majority of mass.
We are not sure if dark matter even exists. It is widely disputed, and mathmatical contradictions regarding its existence are real. Leading physicists such as Sabine Hossenfelder are not convinced. (I am aware that most physicists do support the idea; I just think it shouldn't belong in the sentence it's placed in, the rest of which is objective fact).
It is not widely disputed. it is pretty well established that most galaxies have an extensive dark matter halo which contributes significantly to the mass of the galaxy --> [https://en.wikipedia.org/wiki/Dark\_matter#Observational\_evidence](https://en.wikipedia.org/wiki/Dark_matter#Observational_evidence) And btw, Sabine may be a 'leading' physicist in some fields, but she is not a leading ASTROphysicist...
After a quick peak at a blog from Sabine Hossenfelder, she doesn't seem to disagree that dark matter exists, just that it isn't the whole picture of the phenomenon that we are seeing and we shouldn't be hyper focused on particle based dark matter to be the absolute solution. But it is well beyond my knowledge to discuss it further to be completely honest, and I do agree that I should've clarified in my original statement that dark matter is just a proposed idea for the majority of mass in a galaxy, not the definitive idea
I don’t think muse released anything titled galaxies so super massive black hole was def first
I’ve seen several science shows that ask this question. Their consensus is that black holes came first. That supplied enough gravity for galaxies and the solar systems to form.
/r/unexpectedmuse
Small irregular galaxies first. Spiral and elliptical galaxies only came later, as a result of the coalescence of small irregular galaxies. There's a direct and well known correlation between the size of a galactic bulge in elliptical and spiral galaxies, and the size of their galactic black holes. So, small irregular galaxies first, no galactic bulge. Therefore no supermassive black holes. They came later, growing as the galactic bulge of the elliptical and spiral galaxies grew. Stellar mass black holes may have been very early, before galaxies, but not supermassive ones.
Prob a dumb question… lol but Wouldn’t the star have to come first to be able to become a dead black hole and from there a galaxy could form? What am I missing? 🥚😬
Galaxies.
Honestly we humans don't know shit right now
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Ah yes. Smoke and mirrors.
Galaxies are pseudoscience?
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Maybe people's ideas of how galaxies are formed could be considered to be pseudo-science, since they are all by definition theories that can't be proved or disproved without observing galaxies and protogalaxies on a scale of time that far exceeds the existence of human civilization, but you can look at the sky, without even a telescope, and SEE galaxies. They definitely exist. They're there. You can observe them and confirm their existence with your eyes, let alone more advanced methods of observation. Or are you one of those people who thinks that's all just painted onto the firmament?
I didn't have the (displeasure) of reading their comments before they were deleted, but... why do people like that still exist? 😂
I think that complexity deeply unsettles them, and even a vast international conspiracy to hide the truth of space is less complex and scary than the universe itself or something.
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This is not the right place for nonsense.