Where do things go after they were sucked by a Blackhole?

[at94official]

I'm just wondering if a spacecraft or any kind of matter was swallowed by a black hole , where does the debris go? I know that it will disintegrate, but even the gravity in there is very strong will there be debris left? If there is, Will it go to other dimension or what?

Thanks,
Austin

 

[Chronos]

It's too late to hold much hope for fragments to escape the gravity well once it get close enough to be tidally disrupted. The debris then joins the accretion disc, otherwise known as the buftet line, to feed the black hole. The only way to escape the accretion disc is thru jets where a forrtunate few particles can be accelerated to and escape at relativistic velocities. If a sub atomic particles qualify as 'debris', this is the only know way to escape such an encounter.

 

[phinds]

If "swallowed" by a black hole means "crossed the Event Horizon" (and I can't think what else it could mean) then the object becomes part of the singularity at the center of the black hole. We don't know what the singularity is but may know when a theory of Quantum Gravity is developed.

 

[at94official]

If "swallowed" by a black hole means "crossed the Event Horizon" (and I can't think what else it could mean) then the object becomes part of the singularity at the center of the black hole. We don't know what the singularity is but may know when a theory of Quantum Gravity is developed.

If this is the case, let's say the black hole is keep on swallowing things, and all particles and debris will occupy the center of the black hole? will it affect strength of the particular black hole? or it may result to a new cosmic environment. no?

 

[at94official]

It's too late to hold much hope for fragments to escape the gravity well once it get close enough to be tidally disrupted. The debris then joins the accretion disc, otherwise known as the buftet line, to feed the black hole. The only way to escape the accretion disc is thru jets where a forrtunate few particles can be accelerated to and escape at relativistic velocities. If a sub atomic particles qualify as 'debris', this is the only know way to escape such an encounter.

I'm just wondering for the fragments, where would they go if they can't escape the gravity. IF they will occupy the center of the black hole, isn't it a best place for a new evolution of cosmic activity? Because as what I've understand of black holes is that they are compose of energy (Dark energy or Vacuum Energy). And I believe there is no such thing as infinite energy. So there might be some point that it will slowly loose its gravity.

 

[phinds]

I'm just wondering for the fragments, where would they go if they can't escape the gravity. IF they will occupy the center of the black hole, isn't it a best place for a new evolution of cosmic activity? Because as what I've understand of black holes is that they are compose of energy (Dark energy or Vacuum Energy). And I believe there is no such thing as infinite energy. So there might be some point that it will slowly loose its gravity.

Well, then what you have heard is nonsense.

 

[phinds]

If this is the case, let's say the black hole is keep on swallowing things, and all particles and debris will occupy the center of the black hole? will it affect strength of the particular black hole? or it may result to a new cosmic environment. no?

Yes, it will increase the gravitational attraction of the black hole. I have no idea what you are talking about when you say "new cosmic environment".

I think you should read some real physics instead of pop-science nonsense.

 

[Drakkith]

I'm just wondering for the fragments, where would they go if they can't escape the gravity. IF they will occupy the center of the black hole, isn't it a best place for a new evolution of cosmic activity? Because as what I've understand of black holes is that they are compose of energy (Dark energy or Vacuum Energy). And I believe there is no such thing as infinite energy. So there might be some point that it will slowly loose its gravity.

Black holes are made up primarily of matter, but energy (in the form of light and the kinetic/potential energy of the matter) also contributes. Note that gravity does not require the expenditure of energy to function. In other words, the only way for the black hole's gravity to lessen in strength is for the black hole to lose some of its mass. The only way for this to occur is through hawking radiation.

 

[H G Kellogg]

Is it possible for a 'Black Hole' to reach a critical mass- such as in an exploding star?

 

[nitsuj]

Black holes are made up primarily of matter, but energy (in the form of light and the kinetic/potential energy of the matter) also contributes. Note that gravity does not require the expenditure of energy to function. In other words, the only way for the black hole's gravity to lessen in strength is for the black hole to lose some of its mass. The only way for this to occur is through hawking radiation.

I thought the generation of gravity waves reduces energy.

Edit: hmm I just read the wiki on those waves, and it says it causes orbital decay. I don't think that means less energy (mass) for the body, but for the "system" as a whole. Though such a system is likely to eventually become a single body and it had dissipated some energy "via gravity".

Also frame dragging, I'd think that's a clear example of weaker gravity from a body losing energy (mass).

 

[SteamKing]

Is it possible for a 'Black Hole' to reach a critical mass- such as in an exploding star?

You're confusing two different concepts here.

1. "Critical mass" is a term which describes the amount of nuclear material which, when brought together, will sustain a nuclear chain reaction where the atoms in the critical mass are split by atomic fission:

http://en.wikipedia.org/wiki/Critical_mass

2. Stars don't explode because they reach some critical mass. Stars create energy by using atomic fusion, rather than atomic fission, so there is no critical mass beyond which they will explode. Stars explode for a variety of reasons. See supernova:

http://en.wikipedia.org/wiki/Supernova

 

[Chronos]

There is no theoretical mass limit for a black. IIRC the largest known black hole has a mass around 20 billion times that of the sun. As Drakkith noted, the only way they can shed mass is via Hawking radiation and that process is well beyond painfully slow.

 

[nitsuj]

As Drakkith noted, the only way they can shed mass is via Hawking radiation and that process is well beyond painfully slow.

How is the "Penrose Process" not also a way in which a BH could lose energy (mass)?

 

[Chronos]

The hypothetical penrose process extracts energy from outside the event horizon, so the black hole does not decrease in mass via any such mechanism.

 

[nitsuj]

Hmmm...I'm not sure about the equally Hypothetical Hawking Radiation process (or how accepted it is either, though agree it would have been "reviewed" far more than the Penrose Process), but the Penrose Process decreases the energy of a rotating black hole, is this splitting hairs between mass/energy loss and a decrease in gravity? Since you specifically said the penrose process does not decrease a black holes mass.

Yes it begins outside the EH, but part if the process is a piece of the "attracted object" must "fall" past the EH.

Is the distinction between "rest mass" and energy with respect to gravity relevant for a black hole? When I read a black hole is 20 million time more massive than our sun, does that exclude kinetic energy, pressure ect? I'd guess that value is derived from the observed gravitational effect of the black hole. I can't imagine the calculation includes an estimate of the radiation absorbed because "Oh that's just momentum, not mass. We want to know how massive it is."Just to make clear my point is there isn't only one theoretical way for a black hole's gravity to lessen than it losing mass. In turn it leads to having to say only hawking radiation theorizes a way for a black hole to lose mass, since it was previously said the only way for a BH to have reduce gravity is by losing mass. (despite have made the comment that light, kinetic, momentum contribute to a bh's gravity)

In other words, the only way for the black hole's gravity to lessen in strength is for the black hole to lose some of its mass. The only way for this to occur is through hawking radiation.

What's more, I'm sure if I read about hawking radiation...it will be about radiation...not ejection of matter (rest mass) from the within the black hole. And again it just seems pointless making a mass/energy distinction in this context of changes in gravity of a black hole...why not just call all of it energy?

 

[AgentSmith]

I'm just wondering if a spacecraft or any kind of matter was swallowed by a black hole , where does the debris go? I know that it will disintegrate, but even the gravity in there is very strong will there be debris left? If there is, Will it go to other dimension or what?

Thanks,
Austin

We cannot know for sure, but presumably it is crushed into the singularity. Some do not think an actual singularity can exist, based on quantum mechanics, so the center of the black whole is the smallest meaningful volume, the Planck volume. Either way, the spacecraft is crunched out of existence.

 

[stevebd1]

You can also consider a hypothetical phenomena called mass inflation that occurs at the Cauchy horizon (or inner horizon) of charged (Reissner–Nordström) bh's, rotating (Kerr) bh's or black holes that have both charge and spin (Kerr-Newman). At the Cauchy horizon (r_-) is predicted to be a 'weak' singularity where gravity increases infinitely in a Dirac Delta function, as apposed to a Schwarzschild singularity where gravity (and tidal forces) increase exponentially the closer you get. This seems to be caused by a possible number of things. For a rotating black hole, matter/energy is flung out by a central spinning ring singularity, the outfalling matter meeting the infalling matter creating the Cauchy horizon, this is also predicted to recreate time-like worldlines within the Cauchy horizon. For a charged black hole mass inflation is caused by electrostatic repulsion. Another way of looking at this is at the outer horizon (r₊), outgoing light rays are infinitely redshifted while ingoing light rays are infinitely blueshifted, this balance means the spacetime stays smooth, but at the inner horizon, both ingoing and outgoing lightrays are blueshifted, causing the pinch in spacetime. It's also predicted that gravity waves that fall back into a charged/spinning black hole contribute to mass inflation. If a spaceship is robust enough, it might be able to pass through the weak singularity though the Cauchy horizon is sometimes referred to as the boundary of predictability and the Kerr-Newman case is predicted to be unstable. Here is the old PF library entry for mass inflation which also has links to some papers-

what is mass inflation?

Below is a link relating to mass inflation in charged black holes-

http://jila.colorado.edu/~ajsh/insidebh/realistic.html#inflation

If you also do a search in the forums, you should find various discussions on the subject.

 

[nitsuj]

^^ that's some weird stuff

We need to do something about these black holes, they're making a mess of spacetime :( lol

 

[Quds Akbar]

One idea proposed by Stephen Hawking to satisfy the law of conservation of matter is that the black hole has a life span and when it dies and evaporates everything it has is released back into the Universe, but since there is no way to look into a black hole (which would be nice) what actually happens to the matter inside is a mystery, it may be thrown into other regions of spacetime, no one knows.

 

[Drakkith]

the law of conservation of matter

I'm not aware of such a law.

 

[nitsuj]

law of conservation of matter

I'm not aware of such a law.

You are, more recently referred to as law of conservation of mass. lol

 

[AlephNumbers]

You are, more recently referred to as law of conservation of mass. lol

The principle of conservation of matter is different from conservation of mass.

 

[nitsuj]

The principle of conservation of matter is different from conservation of mass.

Okay and in what way? My understanding is its one if those principals that evolved with technology/measurement accuracy. Both are measured as mass. The more recent term is conservation of mass, whether matter or energy.

 

[AlephNumbers]

Wikipedia has a surprisingly easy to understand explanation. I don't think I could explain to you better myself.

http://en.wikipedia.org/wiki/Conser...ions_or_caveats_to_mass.2Fmatter_conservation

 

[nitsuj]

Wikipedia has a surprisingly easy to understand explanation. I don't think I could explain to you better myself.

http://en.wikipedia.org/wiki/Conser...ions_or_caveats_to_mass.2Fmatter_conservation

I'm not sure what you mean. It says what I said. What's more it meantions specifically its not true for high energy situations. We can now measure this mass/energy equivelance. Since 1930ish.

The only argument I could see is going down to a standard model description of atoms. I don't know if quarks quarks or whatever can be destroyed. Or that because comparatively (density) matter is so much more massive than energy so it generally makes little measurable difference.

Either way the law has been updated since conservation of matter, to the one of the wiki page you referenced

 

[gennarakis]

I'm just wondering for the fragments, where would they go if they can't escape the gravity.

All we know is that matter and all the laws of quantum physics -like the minimum quantum energy or the energy states- collapse. You can't have a periodic element inside a black hole. And I guess mass too, loses its properties as we know it from everyday interaction with it.

To me black holes remain a mystery on the inside since you can't observe anything of the inside (apart from hawking radiation). And I can cope with that.

 

[nitsuj]

...black holes remain a mystery on the inside since you can't observe anything of the inside (apart from hawking radiation).

Can you provide a reference that Hawking Radiation has been observed?

 

[Drakkith]

Can you provide a reference that Hawking Radiation has been observed?

It hasn't, but gennarakis isn't claiming that we've observed it, only that it should be observable.

 

[nitsuj]

It hasn't, but gennarakis isn't claiming that we've observed it, only that it should be observable.

Hmmm... paraphrasing here but they said observe "...you can't observe inside of a black hole ...(apart from Hawking Radiation)." Seemed to imply we have observed nothing of the inside of a black hole apart from Hawking Radiation; and that seemed wrong on two fronts.

Also, what are the "observables" of hawking radiation that "should be observable"?

 

[Drakkith]

I'm not reading it that way.

 

[nitsuj]

I'm not reading it that way.

fair enough.

Here is the strongest support I see for Hawking Radiation...maybe more accurately some form of it.

from the wiki page on Hawking Radiation: "Hawking radiation is required by the Unruh effect and the equivalence principle applied to black hole horizons."

...but apparently may lead to other conflicts that need to be theorized away.

 

[gennarakis]

I'm not a black holes expert. Though, what I was trying to say is that you can't describe something you don't know anything about. Matter inside a black hole probably collapses or becomes into another form. No one will ever know until something is observed. Models help you look at he right direction. You can't predict how the laws of physics behave in a whole new phenomena. We expect them to be the same but they might not. And that's what drives scientists' curiosity to find things out. Beautiful models and assumptions in that case don't differ much from sci-fi stories, dealing with the unknown. What we can directly observe is their radius/mass charge and angular momentum. Hawking radiation is part of a model (and trying to be verified at this time in experiments).

 

[stevebd1]

Is the distinction between "rest mass" and energy with respect to gravity relevant for a black hole? When I read a black hole is 20 million time more massive than our sun, does that exclude kinetic energy, pressure ect? I'd guess that value is derived from the observed gravitational effect of the black hole. I can't imagine the calculation includes an estimate of the radiation absorbed because "Oh that's just momentum, not mass. We want to know how massive it is."

What's more, I'm sure if I read about hawking radiation...it will be about radiation...not ejection of matter (rest mass) from the within the black hole. And again it just seems pointless making a mass/energy distinction in this context of changes in gravity of a black hole...why not just call all of it energy?

A more accurate statement might be '..the only way for a black hole to lose irreducible mass is via Hawking radiation, in accordance with https://www.physicsforums.com/threads/black-hole-thermodynamics.762982/'.

 

[at94official]

We cannot know for sure, but presumably it is crushed into the singularity. Some do not think an actual singularity can exist, based on quantum mechanics, so the center of the black whole is the smallest meaningful volume, the Planck volume. Either way, the spacecraft is crunched out of existence.

Yes, I understand that the spacecraft will be crunched , let's say it will disintegrate into its smallest parts ( Into atoms perhaps? ) But my questions means where do they go? If they were sucked in, it would be impossible for it to go back to event horizon right?

 

[nitsuj]

Yes, I understand that the spacecraft will be crunched , let's say it will disintegrate into its smallest parts ( Into atoms perhaps? ) But my questions means where do they go? If they were sucked in, it would be impossible for it to go back to event horizon right?

A neutron star "crushes" things, beyond atomic structure. Who knows what a black hole does... but "crushed" may not be the right word as it implies things like a surface to "land" on.

The things go "elsewhere".

 

[Drakkith]

The things go "elsewhere".

What do you mean? As far as I understand, matter does not go anywhere. It stays in the black hole, probably in an unknown form or state due to the extreme pressure.

 

[nitsuj]

What do you mean? As far as I understand, matter does not go anywhere. It stays in the black hole, probably in an unknown form or state due to the extreme pressure.

In the same sense of the "elsewhere" region of a light cone...simply a cheeky comment referring to the physical elusiveness...or physical insignificance to an observer (distant)

 

[Sun E Man]

It's too bad that black holes got named as such. They are not holes at all, but the most condensed masses we know about as far from being a hole as anything can get. (That we know of so far.) Food for thought. If two of these masses got close enough to each other their gravitational pull would bring them together at some speed faster than light. That would be a collision of such magnitude that you would think that they would break up and send debris and energy in many different directions. That would be a small bang comparable to "The Big Bang". Or would they just combine and have a new gravitational pull of x + y? It is said that nothing can go faster than light. This is an untrue statement because light goes faster than it's own speed when it enters a (I don't like to use the term) black hole. Think about it.

 

[phinds]

It's too bad that black holes got named as such. They are not holes at all, but the most condensed masses we know about as far from being a hole as anything can get. (That we know of so far.) Food for thought.

Well, "hole" is not all THAT bad a description, since they take stuff out of normal spacetime like putting it into a deep hole

If two of these masses got close enough to each other their gravitational pull would bring them together at some speed faster than light.

Nonsense. Where did you ever get that idea?

That would be a collision of such magnitude that you would think that they would break up and send debris and energy in many different directions. That would be a small bang comparable to "The Big Bang". Or would they just combine and have a new gravitational pull of x + y?

No, they would just merge. Possible there would be debris from one or both accretion disks but nothing from the BH's themselves.

It is said that nothing can go faster than light.

true that it is said and true that it is true.

This is an untrue statement because light goes faster than it's own speed when it enters a (I don't like to use the term) black hole. Think about it.

No, I think perhaps YOU should think about it. Perhaps you are getting confused because of gravitational time dilation but I don't see how even that could lead you to the conclusion that anything travels faster than light.

 

[ShayanJ]

People here said that the Penrose process can't decrease the mass of the BH. I don't want to argue but here is a quote from page 269 of Sean Carroll's SpaceTime and geometry:

We will now use these ideas to verify that, although you can use the Penrose process to extract energy from the black hole (thereby decreasing M), you cannot violate the area theorem:The area of the event horizon is nondecreasing.

 

[Drakkith]

This is an untrue statement because light goes faster than it's own speed when it enters a (I don't like to use the term) black hole. Think about it.

Light falling into a gravity well does not increase in speed, it increases in frequency.

 

[nitsuj]

People here said that the Penrose process can't decrease the mass of the BH. I don't want to argue but here is a quote from page 269 of Sean Carroll's SpaceTime and geometry:

Post 38 by SteveBD used the correct term, "irreducible mass". The Physics Forum faq has an entry on it. Only Chronos said the Penrose Process doesn't reduce mass, and Drak excluded it saying only Hawking Radiation reduces a BH's mass.

 

[Chronos]

Can anyone cite a rerference claiming the Penrose procees decreases the mass of a black hole.

 

[ShayanJ]

Can anyone cite a rerference claiming the Penrose procees decreases the mass of a black hole.

Carroll(like some other sources) defines an irreducible mass by $M_{irr}^2= \frac 1 2 (M^2+\sqrt{M^4-(\frac J G)^2})$ ans says that it can not decrease, hence the name. But he doesn't state clearly whether M can decrease or not. But he says after you extract all the rotational energy of the BH, you'll have a Schwarzschild BH with mass $M_{irr}$.
But section 13.9 of Lasenby's and Hobson's states it clearly and a bit mathematically.(But it doesn't define an irreducible mass).
Also Zee states it clearly in page 471 of his GR book.
Padmanabhan says that too but you can't see it clearly in his calculations.
It seems to me they aren't making it clear which one, $M \ or \ M_{irr}$, they are considering as the mass of the BH!

 

[Akhand]

I'm just wondering if a spacecraft or any kind of matter was swallowed by a black hole , where does the debris go? I know that it will disintegrate, but even the gravity in there is very strong will there be debris left? If there is, Will it go to other dimension or what?

Thanks,
Austin

there is a theory that they come out of a white hole.
but there is a very high gravity inside as F of gravity
F=GMm/r*r
here M is very much large

 

[ShayanJ]

there is a theory that they come out of a white hole.

No there isn't. Black holes that form from collapsing matter, can't have a white hole.

 

[Akhand]

No there isn't. Black holes that form from collapsing matter, can't have a white hole.

Black holes are formed due the reason that they are acting as a hole in the universe and every hole has it's end that is white hole.

 

[ShayanJ]

Black holes are formed due the reason that they are acting as a hole in the universe and every hole has it's end that is white hole.

White holes arise when people maximally expand the manifold with the Schwarzschild metric. Then you see extra regions which one of those regions is called a white hole because of its properties. But the point is, in the case of a black hole formed from collapsing matter, that part of the manifold which we called white hole, doesn't correspond to any point of the spacetime any more because it resides in the part of spacetime containing star's materials which means we should use a different metric there.

 

[nitsuj]

Can anyone cite a rerference claiming the Penrose procees decreases the mass of a black hole.

I don't have a paper to reference, but the wiki, probably does. It said "A consequence of these laws is that if the process is performed repeatedly, the black hole can eventually lose all of its angular momentum, becoming non-rotating, i.e. a Schwarzschild black hole. In this case the theoretical maximum energy that can be extracted from a black hole is 29% its original mass [4]. Larger efficiencies are possible for charged rotating black holes.[5]"

Here is a paper for the charged BH, Link

 

[Sun E Man]

The speed of gravity is faster than the speed of light or it is a constant force that seems like it is faster than the speed of light. Einstein hypothetically did an experiment in which if the Sun were to loose it's gravity in an instant, the planets would instantly swing out of there orbits. The Earth would already be out of it's orbit for 8.3 minutes + by the time the the sun light reached it that started when the sun lost it's gravity. With this thought in mind is what made me think that the two Black Holes whose gravitational pull is is faster than the speed of light would combine accelerating them to something more than the speed of light. There would be nothing to slow them down as they would have already pulled any thing that was in there way on to them selves now just pulling on each other. I believe this would be especially true once that they came close enough so that their event horizons combined. phinds thank you for your reply and please reply again.