Is there an upper limit for how much mass a black hole can have?

is there an upper limit for how much mass a black hole can have?

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>is there an upper limit for how much mass a black hole can have?
1/2 of your mother's mass

No,
but in practice it seems that around 50 bn Sun masses the accretion disk starts producing stars of its own. Their radiation then pushes mass away.

not more than your mother
if your mother falls into a black hole our big bang will reverse and our universe will be a singularity in 13.8 bn years again. please avoid that

Depends on the radius of my cock

No. That's why it reaches a singularity.

what if two black holes with disks collided and pushed some mass into each other?

>singularity.

I think there is a difference between whats inside the black hole and what is outside the black hole. The black hole exists with an event horizon that has a radius because the collapse of the star has expelled much energy but that energy can go nowhere. This explosion of energy pushes back against further collapse. You can only imagine the insane forces be applied at the event horizon, where collapse can go no further yet a gravity strong enough to bend light inward, while the internal explosion is equally just as insane pushing back against this gravity.

So if something fell into the gravity of a black hole, where does it go? Is the internal outward force so great that it cannot enter, squashing and being being scattered across the surface of the black hole? Then how could a black hole grow in size?
Would it be only in the case of colliding black holes that they would have enough specific gravity force at their event horizons to tear each other open, near instantaneously attempting to create equilibrium with each other by combining into a larger black hole?

>I think there is a difference between whats inside the black hole and what is outside the black hole
Your Nobel prize is in the mail
ty Captain Obvious

The total mass of the observable universe around it.

I'm just meaning that, unless you're another black hole, falling towards a black hole will not combine you with the internals of the black hole. You will be scattered on the surface at the event horizon.

According to general relativity, objects cross the event horizon and continue on to the singularity, at least from their own inertial reference frame.

That is not a useful assumption.

It's not an assumption. It's a result of the same math that predicted black holes in the first place.

The schwarzchild radius is what predicts black holes. Singularity defined as a infinitesmal point violates thermodynamics.
If you fudge singularity to instead define X a point on a line where the force of gravity becomes greater than c, then "singularity" would be any value on the line < X, or expressed 3-dimensionally with the schwarzchild radius defining mass and volume, X would be the event horizon. There would be no inward gravitational force at the center of a black hole since beyond the event horizon is an explosion of energy with such magnitude that it prevents any further collapse, or any further shrinkage beyond the schwarzchild radius. If the infalling material towards a black hole is being pulled by a force > c, and the internal explosion within the black hole is being pushed by a force > c, on a line where these two forces meet would be the real singularity, but on a sphere it would be every point on the surface of the sphere.

>Schwartzchild radius predicted black holes

No

More realistically it would look like this. Since the explosion cannot escape and ends up either reflecting off the interior back into itself or maybe something else. In both cases what lies within the black hole and outside the black hole dont seem to actually meet. In the case of a black hole colliding with another, it stands to reason that where their event horizons meet would open a channel between the internal guts of each hole so they can explode into each other, combining into a single black hole.

Please, please stop.
It's great that you have an interest in this, and it seems very genuine.

But you really must look up more about the subject before you explain things like this. There is so little correct about your explanations it leads me to believe you're simply writing what sounds good to you.

It requires more than one-half million years for an X-ray-stimulated electron to work its way from the very center of an average sun up to the solar surface, whence it starts out on its space adventure, maybe to warm an inhabited planet, to be captured by a meteor, to participate in the birth of an atom, to be attracted by a highly charged dark island of space, or to find its space flight terminated by a final plunge into the surface of a sun similar to the one of its origin.

I'm not sorry you're so retarded that you only believe what you read in a text book, as it's not my fault.

Let me then ask where you credit your understanding of all the evidence in your argument.

I assume you derived the idea of black holes, schwartzchild radii, number lines, variables, forces, and gravitation on your own seeing as textbooks are so untrustworthy

What i'm saying is where Book A defines some things and Book B defines other things, because there is no book yet between A and B you presume there is no logical connections to be made between anything in A to anything in B.

that being said, i would love to hear an honest argument against what I claimed rather than ad hominem.

Do any of these books you're reading contain the words "metric"? If not, they're probably popsci.

...

This is simply untrue.
I agree with two things you've said,
Firstly that there are many things that we simply have not proven yet, and current theories are our best guess
Secondly, that mass is spread across the event horizon - this could be true theoretically in pursuit of the conservation of information, but that is beyond the topic at hand

The main argument against what you've claimed is that among everything predicted by science, Einstein's Relativity, QFT - and especially QED within - are among the most supported by real evidence.
The same field equations that dictate Einstein's spacetime suggest it's possible for exotic spacetime curvature in the presence of high pressure (stress/energy or mass colloquially) which we call a black hole. The singularity inside the black hole is thermodynamically irreverent, because it doesn't actually exist. It is a point of infinite mass-density, infinitely far in the future. Upon falling into a black hole, physics is preserved by saying instead of moving forward in time we are moving forward in distance, allowing the time frames of both the observer and you to be relative (ergo they don't see you fall into the black hole)

Of course this is all conditional on the validity of General Relativity, but this like betting on a coin landing completely on its side after being tossed. Sure, it could be possible, but experimental evidence says otherwise.

If the schwarzchild radius did not exist, a black hole would have no volume, and therefore no event horizon. Upon the star collapsing to the point of becoming a black hole, you suggest it continues to collapse infinitely upon itself, but in doing so the horizon would infinitely collapse as well.

Meanwhile is astrophysics and astronomy, stars ready to become black holes as they are "dying", often have much higher rotational spins and energy output than they ever did prior in their lifetime. It stands that there is a correlation between the collapsing fusion and energy output.

Now we take that one step further where the collapse has generated an event horizon, and instead of infalling forever if not evaporating near instantenously or being strangely pushed into another dimension beyond our understanding of space time, the mass retains value and does not lose mass - at least not in any recordable timeframe if hawking radiation is to be trusted.

We now have 2 examples of information we can use to reliably infer things.
I ) a correlation between compacting collapse instigated by fusion increasing energy output exists in recordable information by nature of dying stars, neutron stars, etc.
II ) because the black hole can exist with knowable mass near-indefinitely, it cannot also continue collapsing infinitely, as there is a correlation between collapse and mass defined as the schwarzchild radius. Infinite collapse would mean either (a) the radius infinitely grows or (b) the radius infinitely shrinks. If (b) were true, nearly nothing would be able to fall into a black hole. It would equate to the radius eventually being a planck length where not even an electron could fall into the black hole, and if not even an electron then not a photon, which would begin challenging if light could not escape a black hole when the event horizon is so small that they wouldn't even interact. (b) is thus likely not true based on implied observations of the milky way's hole.

If (a) were true, black holes would suck up everything and there would be no such thing as a near miss.

III ) So because a black hole maintains mass, amd because there is a correlation between collapse and energy output, when a star becomes a black hole, the specific mass causing the event horizon would prevent any energy produced from escaping, feeding back into itself.

We can debate if theres an explosion going on internally or if it's just some ultra dense heat fluid matter, but it is not debateable that the contents of the black hole are collapsing any further. With a black hole 3 kilometers wide of radius 1.5km, it is not intelligble to assume there is any greater force at 0km.r deadcenter than 1.4km.r

The densitity of the contents may be so great globally as to mean no further collapse can happen and it may not even be hot at all. It could be an area devoid of time and without time, no movement, and thus no positive temperature - so anything falling into a black hole would actually be falling onto the black hole on a surface area - a wholly homogenous structure of compacted material than can compact no further resting at absolute zero, where accumulation of outside material merely layers like an onion or a crust.

>So if something fell into the gravity of a black hole, where does it go?
From the outside perspective, it never reaches the Event Horizon, as time slows down. From the victim's perspective, they follow the waterfall of space time heading towards the singularity, effectively infinitely far in the future. Due to time dilation, near the entire life of the universe will appear to go by in an instant from above as they fall. Also, for other odd reasons, time-like coordinates become space-like, and visa versa, with the singularity representing the arrow of time towards the future, rather than a location.

>Is the internal outward force so great that it cannot enter, squashing and being being scattered across the surface of the black hole? Then how could a black hole grow in size?
There is no internal outward force. The Event Horizon grows in size as it contains more mass.

>Would it be only in the case of colliding black holes that they would have enough specific gravity force at their event horizons to tear each other open, near instantaneously attempting to create equilibrium with each other by combining into a larger black hole?
Two black holes just make a whole lotta ruckus followed by bigger black hole - as we've observed. There is a theory, however, that if you got a ring of black holes arranged properly, you could, at least temporarily, expose a naked singularity, which theoretically, should lead to an extreme gamma and x-ray burst, though no such matching phenomenon has yet been observed.

>but in doing so the horizon would infinitely collapse as well
Why? I feel like you don't know what an event horizon is.

It's a practical limit, not an absolute limit. Another black hole, or even a star with sufficient relative velocity, could still enter the black hole and cause it to grow yet more. It's only that most things attempting to enter the black hole are going to get "quasared off".

I suppose the only hard limit would be the mass within the observable universe from the Event Horizon's perspective. There's some question as to whether you could call it a black hole at that point, however. Similarly, if space is compact and uniform, you wouldn't have enough discontinuity for the black hole to exist.

>There's some question as to whether you could call it a black hole at that point
You mean if a black hole hypothetically sucked up every piece of matter?
If the density of a black hole decreases in density as it grows in size, and you threw everything and the kitchen sink inside, would it stop being a black hole and just basically revert to "normal space."

Jayzus you guys, is it so hard to consider the implications of mass being broken down into sub-sub-atomic pieces as it's sucked into a black hole?

Think about it: at some point matter is stretched to the point that its comprising atoms themselves are stretched, pulled apart as the furthest-inward pieces accelerate faster than their neighbors.

there can only be some point beyond which even the smallest known pieces of atoms are themselves broken down into their components, and those components also broken down, and so on.

it's a recursive effect, where pieces that continually require less and less space to remain next to each other are packed further and further together, nearing the center.

now, what could Hawking radiation be? what could happen to smaller-than-imaginable pieces of reality as they're continually accelerated toward some center point, given the concept that they could only circle toward it in a collapsing orbit and never actually reach it?

I, for one, must assume that there is a point beyond which those pieces are not subject to gravity, and their velocity causes them to exit the black hole in a manner that Hawking radiation approximates.

Maybe... There's an interesting theory involving singularity-free black holes that runs along those lines, saying that our own universe is a series of such black holes inside one another, matryoshka doll style. It doesn't really fit with certain key observations, but it's an interesting thought experiment:
insidescience.org/news/every-black-hole-contains-new-universe

>Jayzus you guys, is it so hard to consider the implications of mass being broken down into sub-sub-atomic pieces as it's sucked into a black hole?
Actually, unless Cosmic Censorship is a thing, this isn't necessarily the case for very large black holes not taking in a whole lotta matter. You could, theoretically, enter the Event Horizon of such a supermassive black hole unharmed. The gravitational distortions wouldn't become a problem until you got closer to the singularity.

>it's a recursive effect, where pieces that continually require less and less space to remain next to each other are packed further and further together, nearing the center.
Nothing ever actually reaches the singularity, as it is eternally collapsing. The problem with this idea is that the birth of the black hole itself is the result of a mass so dense that there are no forces left that can prevent it from collapsing. It's just going to collapse forever, until it's unwound by Hawking Radiation. Any matter that enters after that event, is just along for that effectively infinite ride.

>now, what could Hawking radiation be?
Hawking radiation introduces a number of problems - but the idea is that virtual particle pairs at the edge of the horizon fail to match up. Nothing actually exits the black hole, it's only that the unmatched particle on the edge has enough momentum to affect other particles that fail to enter the hole and thus release as gamma rays. Its twin enters the black hole, and annihilates with matter inside instead of its pair as it normally would. Ya get into weirdness with either violation of information preservation or causality depending on which variant of the theory you use (either something is effectively erased, or some portion of the mass that created the black hole is "borrowed" in time - which, given the nature of time inside an Event Horizon, is not quite as paradoxical as it sounds, but still ugly.)

>is it so hard to consider the implications of mass being broken down into sub-sub-atomic pieces as it's sucked into a black hole?
Yes, this violates all standard models.

> what could Hawking radiation be?
EM radiation caused by the spontaneous creation of matter and antimatter particles at the event horizon.

>I, for one, must assume that there is a point beyond which those pieces are not subject to gravity, and their velocity causes them to exit the black hole in a manner that Hawking radiation approximates.
By virtue of gravity bending spacetime, this point never exists. Take light for example, it is massless but is still drawn by gravity.

It's a good thought experiment you're having but most of this stuff is already well documented.

If the contents of a black hole were under such pressure that they'd be dead at absolute zer with no movement, that doesn't exactly explain why a black hole would have rotation.

Actually is there any proof blackholes actually rotate? Or is that based solely on the idea that matter around the black hole orbits it?

It's not like you can see the surface of a black hole to actually measure local rotation.
If a black hole actually does rotate, then the contents would have to be explosive in nature providing an evident force to combat further collapse. If it doesnt rotate, it's likely the contents are dead at absolute zero and the compacted material is homogenous through and through. In the nonrotational example, any matter falling into the black hole would be squashed on the surface with such force that it breaks down completely to an elementary particle that becomes indistinguishable from any other completely broken down particle that makes up the black hole, and any sufficiently large mass colliding with the black hole would near instantaneously be spread across the entire surface area of the event horizon to create a perfect sphere, where each completely broken down particle is forced to scatter across the surface until it can find an equilibirum cranny to settle down into rather than collission occuring and making a big lump on the surface.

>is there any proof blackholes actually rotate?
Frame dragging.
Also the star it came from was rotating, and rotational speed increases as the radius decreases to conserve angular momentum.

The singularity *technically* doesn't rotate, as it doesn't have dimension, but the event horizon retains the rotation of the mass that created it (which tends to be rather extreme - having been a neutron star at some point during that collapse). The collision of the two black holes we observed back in August indicate that both had rotation, though there's some debate as to how much that rotation slowed as they got close enough to gravitationally lock one another - the smaller of the two may have nearly stopped spinning.

Observations of frame dragging around Quasars are also good indicators that black holes not only spin, but tend to have rather extreme spins - much like their precursor Neutron Stars.

>If a black hole actually does rotate, then the contents would have to be explosive in nature providing an evident force to combat further collapse. If it doesnt rotate, it's likely the contents are dead at absolute zero and the compacted material is homogenous through and through.
Eh... A black hole isn't really a solid object. It's better described an infinitely deep hole of space - a cascading waterfall of spacetime that nothing can "swim up" from. There's, effectively, an infinite amount of room for mass inside. The Event Horizon only expands from our perspective due to the mass that is inside (and from our perspective, aside from the origin mass, its is all on the outside, until red-shifted to invisibility). None of it is anymore crowded or compact than when it first went in - kinda the opposite, it's stretched out over a never ending cascade of spacetime. (The exception being the singularity itself, which is no longer classical matter.)

>this violates all standard models
It's a given that I've only supposed it's possible that acceleration of parts could cause separation, but why do standard models find this not possible?

>by virtue of gravity bending spacetime, this point never exists.
That's kinda the point of the thought-experiment, here. If something like a Higg's boson might exist, there may well be a "smaller" comprising piece that would not be subject to gravity--at least in the ways we can observe and predict with known pieces. It's a pointlessly speculative thing to imagine, but perhaps useful in considering the behavior of reality concerning black holes.

>most of this stuff is already well documented
There's a great deal more thought and conjecture than overation, IMO. Most is based on conjecture and assumption, so it doesn't seem inappropriate to try new things.

>Cosmic censorship...
Aptly put, but we aren't exactly presented with those situations, observationally.

>Nothing ever actually reaches the singularity, as it is eternally collapsing.
I'd written, "given the concept that they could only ever circle toward it in..." etc., but out of the idea that a center of gravity could be sustained within a vortex necessarily without matter at its center. Frankly, the idea of continual, eternal collapse just doesn't make sense without non-hand-waving provision for internal contents. Yes, spacetime may be warped, but it ought not be entirely isolated into abstraction by that warping.

It is precisely the problems with Hawking radiation that I've been thinking of. Speculatively, a "singularity" might be only a frame-of-reference issue in which matter behaves in ways that have caused prior studies to misrepresent it.

A whirlpool does not send water continually inward, why should its cosmically-furthest counterpart do the same?

pardon, *observation

If so, it suffices to also say that high enough rotation could counteract gravitational collapse, as the rotation attempts to toss away shit like a wet ball being spun and the water being flung off.

So i would still say that the innermost contents of a black are a contained explosive energy that are active and preventing further collapse, but probably not from any ongoing fusion unless there is some further concept that says a system can still fuse if the resulting energy has nowhere to go. A stick of TNT sealed inside an inpenetrable container with enough air to keep the fuse lit, when the TNT ignites, how much ignites? The initial explosion of fire at the end of the fuse would consume the rest of the oxygen in the container, and without oxygen no fire, and no more energy to consume any unignited powder. Yet the contained force of the explosion has to factor in there somewhere. If the container were left to sit an hour and then somehow opened from the outside - as soon as it could attempt equilibrium with the outside pressure, would it then explode outward as if to be expected at the moment of detonation an hour prior? Would that interior pressure generate enough heat to ignite the remaining TNT even after the oxygen had been consumed or is there a definite upper limit to how much reaction can occur in a closed system where because X amount of energy and pressure exists at the limit Y, X=Y, that even though there is fuel for more explosion the fuel will not be consumed? If so, what remains as the contents of a black hole could very well be an actual star with layers of elements and potential fusion, trapped along with all the emitted energy that would inspire more pressure and more fusion up to a point.

Or maybe a better translation would be encapsulating the stick of TNT a mere moment after it has exploded to be analagous to a situation where all possible fusion potential has occurred in the collapsing star just before it has the time to expel.

what if the innermost contents of a black hole was only void?

What if there was a point beyond which things just weren't there anymore?

>A whirlpool does not send water continually inward, why should its cosmically-furthest counterpart do the same?
Cuz it's a whirlpool with no bottom, and it's not made of matter, but space. The space inside the Event Horizon is falling at faster than the speed of causality, which causes the whole "everything beyond this point is no longer part of your reality" effect to begin with.

The sort of thinking you are applying works better with Neutron Stars and Quark Stars, where at least quantum physics still applies. Here there are things preventing a collapse, if barely. Things get more wonky when you have an infinite collapse as with black holes.

...Also, this talk of "violating the Standard Model" - leaving aside the fact that a singularity defies all analysis (which is why Einstein proposed there must be some hereto unknown mechanism preventing such collapses, until we started observing Event Horizons) - the Standard Model doesn't even work with regular gravity or general relativity, nevermind a black hole.

>If so, it suffices to also say that high enough rotation could counteract gravitational collapse
Some Neutron Stars rotate at close to the speed of light. This doesn't stop them from collapsing. Centrifugal force isn't what ya think it is.

>a whirlpool with no bottom... ...space.
This doesn't bother me, though the idea is outside any other observable form of matter. I'm somehow happier thinking of matter as destructing into a non-matter-esque particulate which can escape than consider that matter could be forever trapped.

I'd rather think singularities mis-named, as though the thinking of isolated loners had characterised it.

Near c is not the same effect as >=c which defines the event horizon.

It's silly but shit like this might be real reason for concepts like 0.999... ≠ 1, unless the near c value is determinable.

The idea of all this is for providing reason for the event horizon to exist with a definite radius rather than collapsing any further, so there must be some counteracting outward force within the black hole doing this.

Relativity is pretty much the most thoroughly tested theory around - and you can test it yourself, anytime you want - just whip out your cell phone and see if it knows where you are.

Millions of scientists have been trying to kill singularities for near a century now - and that includes Einstein. They are ugly, because they represent a point that is literally barred from understanding, that you can't even say anything mathematically about, aside from "yup, that's a singularity". They are, however, the only force in the universe that could create the sort of gravitational warping we see, despite all the thousands and thousands tried and proposed alternatives that all failed both observationally and mathematically.

There's going to be a lot of things in physics you "don't like", but as you research them, you'll find more and more that they are true (indeed, sadly, if you don't like something in physics, that's a good clue it's going to be true.) You aren't going to get very far in your understanding of the universe if you ignore all the reasons why something you don't like may indeed be true, simply out of an obstinate personal preference.

>all this is for providing reason for the event horizon to exist with a definite radius rather than collapsing any further
Event horizons don't collapse - they are the collapse. They aren't solid objects made up of things - they are holes.

well. put.

still, there may be another way.

as a grazing hominid respecting another, goodnight to you.

Nah. You defy logical thinking with that assumption. Maybe watched too much sci fi.

You cannot discover without bias, as without comprehension for what is normal, you cannot recognize the abnormal. If you take scientific knowings and understandings of how various physical laws work and interact with one another, you can make assumptions about black holes that fit into those understandings without violating various laws of nature, which the idea of evercollapsing infinite density actually ends up violating a lot of understandings.

I keep seeing this as a common underpinning of arguments on Veeky Forums desu : a division of understandings and fields where focusing inward and self reference becomes the behaviour for explaining more complex or abstract concepts, which of course natural fail when cross referenced with different fields of understanding almost as if to say science is not a thing at all, but that there are instead numerous science fields which try their damndest to be proven right be self reference rather than cross reference.

>You cannot discover without bias, as without comprehension for what is normal, you cannot recognize the abnormal.
This is oddly exactly what I'm saying.

We get a lot of guys on here who balk at some element of fundamental physics or other, who think they have that "one alternative answer" that will make it "right" to them, and thus set make comfy their vision of the universe that the current theories so threaten.

I mean, nevermind all the anti-intellectual trolls we get swamped with, trying to say every bit of science is wrong for , just start a thread on Block Universe, and watch the abject rage that will result even from the main stream science folks who probably learned this stuff in high school, and just filtered it out when they heard about QM.

The more unintuitive or disturbing a fundamental scientific underpinning in the mainstream is, the more people have attempted to topple it. If you see something truly bizarre, thousands of better men than you have tried to disprove it, thousands of times. So, before you attack it with no knowledge whatsoever, please, learn why it is first, and further, way so many other things rely on it being so. Then, when you have a broad understanding of the interrelations and why you can't pluck out "this one thing you find disturbing", you can start looking for reasons to take it down.

Contradiction is not argument and belligerence is not having an open mind. It's self-enforced ignorance at best, solipsism at worst. Learn the difference.

I mean, unless you just wanna troll - then as you were.

The Schwarzchild result was one solution (among many) of Einstein's general relativity field equation, you stupid, pathetic, ignorant fuckhead.

So, infinite mass?

From the fact that the event horizon is just space it can't rotate and just what is outside that rotate
To possible having momentum in a black hole is the singularity that should rotate

I dont get it where the collapse things came from
Where should a black hole collapse in itself?

You didn t know but the newton result is a result of einstein work so einstein discovered gravity

Space rotates just fine - just needs mass to perturb it enough to do so, which the Event Horizon contains, in spades.

A singularity can't *technically* rotate for the simple reason that it has no surface. It's a single point with no dimensions of its own that defines the spacetime (or in this case, timespace) around it.

It becomes less where, and more when, but I maybe over complicating things with that factoid.

Stars prevent collapsing against their own weight by fusion reactions, but once the hydrogen runs out, and the star starts fusing iron, it can fuse no more. Thus, the outward force of the fusion is no longer sufficient to prevent gravitational collapse (insert mom joke here). Core collapses, star goes boom.

If it's lucky, the collapse will be stopped by neutron degeneracy pressure (and if really lucky, possibly by quark degeneracy). If the star is still too massive, they'll either skip this step entirely, or slow for awhile in this state before collapsing. At that point (about 3 solar masses pact down to about the size of the moon), there is no mechanism that can prevent the collapse, or even slow it. It happens all at once, and at faster than the speed of light (cuz while matter can't do that - space can).

At this point, from an external view, a singularity and related Event Horizon form simultaneously. Inside, space and time flip, with the singularity no longer representing a point in space, but a point in time, effectively, infinitely far in the future of this closed universe, with the last light of the star just behind. (Hence the more when that where comment.)

From the outside, the Event Horizon, for all intents and purposes, replaces the star, having no more gravitational pull than the mass that created it. Only, as more and more matter and energy falls in, it contains more mass, and thus expands. As others have stated repeatedly, from the outside perspective, due to time dilation, that mass stops at the Event Horizon, slowly red-shifting into invisibility. From the perspective of the matter or energy so caught, it does indeed cross that horizon, and begins an infinitely long journey towards that infinitely collapsing singularity infinitely far in what is now its future.

Might be worth noting that, since space is collapsing towards the singularity at faster than the speed of light, objects inside the Event Horizon do not necessarily "spiral". They should retain the angular velocity they had going in due to the spin of the black hole (which is generally considerable, as that collapse involves a huge increase in rotation, whether the original star skipped the Neutron Star stage or not), but in some sense, space is so stretched here, it might as well be a straight line towards the singularity.

If you took a spaceship into a very large and calm black hole, and cosmic censorship isn't a thing, you could, in theory, control your direction within the black hole. Much like you can never travel to the past in the regular universe, you can never travel back towards the event horizon in this one, and any movement you do make will drive you faster forward in "time" towards the singularity. As you traveled in this fashion, however, the light intersecting with you would be coming from different periods, so it might look as though you're traveling through time as you move through space. ...and if you look back towards the event horizon, as you enter, there's the disturbing realization that you just watched your whole universe die of heat death - assuming you didn't blink.

Mind, once inside an Event Horizon, anything described gets very dicey, theory-wise. This is just an amalgamation of possibilities based on how it "should", more or less, work. There's no way to test it, as even if we had access to one, Event Horizons use the same slogan as Las Vegas.

Shit's weird - that's why so many folks, including the folks that discovered the math that predicted them, kept trying to debunk these things. As of yet, however, no other valid explanation for those massive Event Horizons we see.

The mass of the observable universe isn't infinite. For us it's about 3e+55g (including dark matter), plus or minus whatever new factor that comes along to fuck that up, but not infinite. Might be more or less for another black hole somewhere, but *probably* not that much different, particularly if its observable universe overlaps with ours.

This might be a retarded question, but you think, as its falling down that hole, matter could form a star with planets inside the black hole?

Source?

Theres an idea that Singularities spawn universes inside themselves, that may have black holes of their own that form still more sub-universes.
But I think the official stance on what happens inside a singularity is that all bets are off.

It's a neat thought, and I suppose there's some variants mentioned in this thread that would allow that sorta thing, even if observations kinda kill them (). In the end, however, space is just too stretched out too quickly. Pretty soon your feet are moving towards the black hole faster than the speed of light relative to your head, thus no electric signals can travel between them - they effectively don't exist to one another. Similarly, the extreme shape of space quickly makes it impossible for matter to gather together, or even hold together atomically. Everything is spaghetti, as they say.

Though - in the case of a 50 billion solar mass black hole (not that we've ever seen anything like that - think we top off at 37b), assuming Cosmic Censorship doesn't shred you as soon as you cross the horizon, and you don't get quasared off, maybe something the size of a small star could keep shining for awhile before shit got too steep. Dun think you'd have 'time' to form a new one though.

Well I mean if you think about it, if there's an infinite well of space, there's a chance there's a few Boltzmann brains spawned in there if that theory is correct.

Not him, but:
newscientist.com/article/dn28647-black-holes-have-a-size-limit-of-50-billion-suns/

It isn't a "hard" limit though, just a naturally practical one. Basically the resulting quasar is just too active for anything to normally get in, and what does isn't going to grow it much more. However, if it hits a similar beast, all bets are off.

Heh, I suppose... Though maybe not beyond a certain 'depth'. Even a Boltzmann brain has to have a certain volume and connectivity to have that moment of false consciousness.

Yes. But it's 'way up there.phys.org/news/2008-09-astronomers-upper-mass-limit-black.html

The supermassive black holes at the centers of galaxies can, theoretically, mass as much as 50 billions Suns. Link explains why there's a cut-off.

>One possible explanation put forth by Natarajan is that the black holes eventually reach the point when they radiate so much energy as they consume their surroundings that they end up interfering with the very gas supply that feeds them, which may interrupt nearby star formation
That wouldn't be a problem if you kept slamming black holes into each other.

>"I'm not sorry you're so retarded that you only believe what you read in a text book, as it's not my fault."
>emoji
brainlet detected

black holes expell hawkings radiation

No, because black holes don't exist.

i like it

for what it's worth, i'm with you user

what are the current theories linking black holes, dark matter and dark energy, kind user?

You seem like a feg. But i agree, everyone needs to step back and stop only believing a textbook.

None that I know of... Other than dark matter isn't black holes, and I guess Hawking radiation and dark energy are loosely related, being different manifestations of vacuum energy. Well, and quasar energy is probably more than it should be, due black holes forcing to dark matter to annihilate.

Dark matter does share a similarity in its scientific history, I suppose. Non-baryonic matter (matter that only bonds with the weak and gravitational forces) was something that was theorized to exist well before these non-uniform gravitational eddies were observed helping to form the odd galactic sinu we see throughout the universe. It seems it maybe the best explanation for this dark matter effect. In the same way, black holes were a mathematical possibility that many thought would not be a reality, that turned out not only to be so, but also fundamental to the universe's formation. In both cases, while their effects are readily observable, neither has been directly observed. (Difference being that you can't directly observe a singularity in an event horizon, by definition, while we may one day directly observe dark matter - and while there's currently no other working theory for the event horizons we see, there's more hope for alternative explanations for the dark matter effect.)

Dark Energy is a bit different, as it's really just a matter of how much energy there is in the quantum field's vacuum energy and the zero state. Right now, the math behind that, and our observations, do not match up at all, which is the current "Vacuum Catastrophe" in cosmology (not to be confused with "False Vacuum" which is a possible catastrophe of an entirely different sort). The universe's expansion is accelerating, so we know it's there, but it isn't what the math says it should be, thus this *shrug* name "dark energy".

For anyone curious about black holes or OP's question, it's probably best to avoid this thread, which is filled with misinformation.

There seems to be an upper limit, and the question is interesting, but the arguments necessary to understand it are technical and quantitative. If you really want to answer this question, your best shot is checking out Hartle or Schutz's General Relativity books, and then reading the relevant parts of the literature. The papers I'm referring to don't require a super deep understanding of GR -- Schutz or Hartle should allow you to understand the gist.

You can get the pdfs/djvus on libgen.

>Hartle or Schutz's General Relativity books
I don't think you'd find any such in there... There is no *mathematical* limit to the size of black holes. The only one I'm aware of is a result of their interaction with matter around them. I mean, you might be able to *infer* that a semi-quasar would repel far more matter than it takes in at a certain size, but such literature isn't going to give you that directly.

Not that I'm discouraging reading such books, just saying, they won't mention any such limitation.

I didn't mean to say those books directly answer the question, you just have to read an introduction to the subject to be able to evaluate whether or not the research published on the topic is correct.

True... Though that particular approach might be akin to learning to read binary in order to to debug Pearl. There might be some more "macro" oriented works that also contain the relevant formulas. Frolov & Zelnikov wrote a good book called "Introduction to Black Hole Physics" in 2011, for instance.

Though, as always, the only true path involves seven years of grad school.

> stop only believing a textbook
...as opposed to, what, your intuition?

Unless you're a billionaire, you're going to have to depend on textbooks for observational data - or at least logs. I suppose interviews with the folks involved also helps, but, if you can't get ahold of them in person, the best interviews are, of course, in textbooks.

There's little observational data involved, in this case, and a good textbook will contain the math. So - if you don't believe it - just do the math yourself.

If you can't do any of that, then books and schooling are indeed your best source of information.

>From the outside perspective, it never reaches the Event Horizon, as time slows down.

If we can't see anything ever go in, how does it form in the first place?

The initial Event Horizon forms from our perspective instantaneously. As for things that go in later, they add to its mass as they hover at the edge of the Event Horizon, creating the expansion effect.

Also:

so, the universe's expansion could be accelerating because of vacuum energy produced by black holes?

also
>dark matter isn't black holes
why would that be indubitable?

So our expanding universe is because we're encoded in the 2D surface of an expanding black hole?

No no... Vacuum energy is the energy inherent to spacetime due to the quantum fields. The whole "empty space isn't really empty" thing.

But as a consequence of that same empty space not really being empty thing, virtual particles are constantly manifesting in the quantum fields in pairs, and self-annihilating. At the edge of the an event horizon, every so often, the two get separated - one goes on its merry way, and the other annihilates a bit of the black hole instead. (The smaller the black hole, the more often this happens, so very tiny black holes put off tons of radiation, and don't live as long as big ones, which live practically forever.)

>dark matter isn't black holes
>why would that be indubitable?
Dark matter is merely non baryonic matter. Some might get inside black holes, like any other matter, but that's about it. Unlike an event horizon, dark matter doesn't swallow light - non baryonic matter has no electromagnetic force, so instead, photons pass through it - though they may still have their paths bent by its mass, as it does have gravity.

Dark matter comes into play in the discrepancy in quasar energy outputs (quasars being angry black holes), as when it gets compressed into itself sufficiently, it self annihilates, releasing gamma energy. It has no weak nor electromagnetic ties, so this can only happen under extreme circumstances, such as inside a quasar's accretion disc.

> we're encoded in the 2D surface of an expanding black hole?
Meh, the Fermilab experiment more or less killed the holographic universe hypothesis. I felt it was silly to begin with, as it's really just an excuse to deal with the information paradox caused by some explanations for the internal mechanics of Hawking Radiation.

Every fundamental laws of thermodynamic break down in extreme circumstances, at least locally. So I dunno why folks got so hung up under that idea when there's a black hole involved.

We're expanding due to dark energy - probably.

Meh, good as video as any, if ya got 15 minutes:
youtube.com/watch?v=UwYSWAlAewc

Dark matter and vacuum energy aren't directly related to black holes - because, as a wise man once said, SCIENTISTS ARE SHIT AT NAMING THINGS.

Even black hole isn't very good - might be more accurately described as a "cosmic drain hole". Dark matter is better described by its technical term - "non baryonic matter", although that gets confusing when you get into baryonic dark matter, which is just regular and dark matter mixed together, so "non-reactive matter" or "non-interfaced matter" might be better still. "clear matter" if you're trying to stick to those 1000 common words.

Vacuum energy might be better thought of as "space energy". It's the energy in the fabric of space itself.

beautiful desu

Are there such things as Dark Black Holes?

I'm convinced any singularity is either another universe entirely or another place or time, nobody can convince me otherwise, It seems to line up with nature and birth/rebirth we see everywhere.

cont

If my meme-tier understanding of matter and dark matter is correct, then a black hole is where they both reach singularity, i.e. interface 1:1

Please cite me in your papers.

a lot of people feel like that

why couldn't dark matter and dark energy be just one thing?
i mean like light is a wave and particle or something

>Dark Black Holes
You mean... A black hole made entirely of dark matter? Cuz they be perfectly black, and I don't think you get any darker than that, outside of Africa and some parts of New Jersey.

I'd be thinking no... Dark matter has mass, but as it compresses it self-annihilates - but mind, this doesn't happen under normal circumstances for a reason. Without a strong or electromagnetic bonding, well... Imagine you're falling to the Earth and you go through it each time, unless you hit a particle at the very center - that's kinda what happens, except there's a bunch of these Earths, so dark matter particles are constantly falling into one another, accelerated by that, missing, and flinging themselves off to other dark matter particles that in turn do the same to them. Dark matter is thus very spread out, chaotic, and in a sense, gaseous, thus these sticky, cloud-like formations of mass we see as a result.

So you'd have to compress it a LOT, and it takes something like the force of a quasar to do that. Problem is, when the particles finally do actually hit each other, they self-annihilate, releasing energy.

So you'd have to find some way to instantly get three solar masses of the stuff into one place, packed together closer than Neutrons in a Neutron star, before they collided and self-annihilated. I can't think of any natural phenomenon that would cause that, but maybe if you're some kinda magi-tier alien tech civ, you can arrange a bunch of black holes together into some sorta funneling device and work it out.

>I can't think of any natural phenomenon that would cause that
what about random collision? like for everything else?