Liberate all the matter from a black hole

[ugalpha]

So let's say that in my universe Dark energy would get stronger with time.

Could it liberate all the matter stucked on the black hole with suficient repulsive energy?

if not

What if i got dark energy of infinite repulsive energy?

What happens to the black hole?

Does all the matter gets liberated from the gravity of the black hole?

CRAZY i know...


Thought*(don't know how to edit the title)

 

[Simon Bridge]

Since it is your universe - you can make any rules you like.

Note, though, that a BH is not a place that matter gets sucked into - it is the result of having a lot of matter in one place. You don't hoover matter out of it like you are describing.

 

[ugalpha]

Why not? gravity is holding it there isn't it ? what if i got enaugh repulsive energy to overcome that gravity?

 

[Drakkith]

We cannot get infinite dark energy, and black holes are not thought to work that way, so your answer is no, we cannot get the matter out of a black hole.

 

[Simon Bridge]

You'd release a lot of energy.

The exact effect would depend on exactly how you went about it.
But what you just suggested is ironing space-time flat. What is gravity, anyway?
As Drakkith says - not how it works.

Set up the rules in your universe right and all that energy pops into existence as a big pink rabbit.

You seem to be imagining a black holes as a kind of bag of the sort you can take things out of... which is the main problem here. Other than your constraints being a little ... unconstrained. Remember - you can make up any kind of universe you like - perhaps you'll be happier in a sci-fi forum?

Otherwise: what is the physics you are trying to explore here?

 

[ugalpha]

i think that yes black holes are tought that way .
compact objects of infinite density holding all the matter that goes through the event horizon just like Earth holds me to the ground, the only difference is that nothing can come out of its gravitanional attraction unless going faster then light.
I just don't see how a repulsive force stronger then the attractive force of a black hole could not free its matter of the gravitational attraction

 

[Drakkith]

i think that yes black holes are tought that way .
compact objects of infinite density holding all the matter that goes through the event horizon just like Earth holds me to the ground, the only difference is that nothing can come out of its gravitanional attraction unless going faster then light.
I just don't see how a repulsive force stronger then the attractive force of a black hole could not free its matter of the gravitational attraction

Because the gravitational strength would get stronger as you get closer to the singularity if it exists. At that point it would take an infinite amount of force to disrupt the singularity.

 

[ugalpha]

a bag of the sort i can take things out of ...not really.
a compact object of the like of a star , yes

i see black holes for what they are, very dense object with immense gravitational force

 

[ugalpha]

Because the gravitational strength would get stronger as you get closer to the singularity if it exists. At that point it would take an infinite amount of force to disrupt the singularity.

So infinite repulsive energy VS infinite attractive energy

i wonder what would happen

 

[ugalpha]

You'd release a lot of energy.

The exact effect would depend on exactly how you went about it.
But what you just suggested is ironing space-time flat. What is gravity, anyway?
As Drakkith says - not how it works.

Set up the rules in your universe right and all that energy pops into existence as a big pink rabbit.

You seem to be imagining a black holes as a kind of bag of the sort you can take things out of... which is the main problem here. Other than your constraints being a little ... unconstrained. Remember - you can make up any kind of universe you like - perhaps you'll be happier in a sci-fi forum?

Otherwise: what is the physics you are trying to explore here?

Theoretical physics but you can call it science fiction.
Given that we know litle about dark energy and that it may or not get stronger with time i think that we need to address the issue of dark energy and black holes. What if in trillions of years all that is left of our universe is supermassive black holes scattered throughout the cosmos and that suddenly dark energy gets strong enaugh to release all the inormation that these black holes contain. Multi Big bang theory YES! that's the name of my theory!

 

[phinds]

Theoretical physics but you can call it science fiction.
Given that we know litle about dark energy and that it may or not get stronger with time i think that we need to address the issue of dark energy and black holes. What if in trillions of years all that is left of our universe is supermassive black holes scattered throughout the cosmos and that suddenly dark energy gets strong enaugh to release all the inormation that these black holes contain. Multi Big bang theory YES! that's the name of my theory!

Flights of fancy can be interesting but if you want to do any good for your own brain, you would likely find it more helpful to think about actual physics.

 

[ugalpha]

this is physics

 

[Simon Bridge]

OK - show us the physics.

 

[ugalpha]

working on it

 

[DaveC426913]

Our current laws of SR and GR prohibit infinities. Sorry.

The reason things cannot escape a black hole is that the escape velocity exceeds the speed of light.

Since no mass can reach, let alone exceed the speed of light, no amount dark energy or any other fanciful evocation can extract it.PF forbids wild speculation. This thread is definitely wild speculation. ugalpha, please read the PF rules on overly-speculative posts.
https://www.physicsforums.com/showthread.php?t=414380

I don't know how it survived 24 hours already but ... lock commencing... 10 ... 9 ... 8 ...

working on it

Great. When you publish it in a peer-reviewed journal, please be sure to return and point us at it, we will be very interested.

 

[ugalpha]

im not talking about anything beyond the event horizon escaping the gravity of the black hole. I am talking about completely bursting it open with a stronger repulsive energy

 

[Simon Bridge]

Given that we know litle about dark energy and that it may or not get stronger with time i think that we need to address the issue of dark energy and black holes. What if in trillions of years all that is left of our universe is supermassive black holes scattered throughout the cosmos and that suddenly dark energy gets strong enough to release all the information that these black holes contain

... let's see if I understand you:

if the universe goes through a stage where there are only SMBHs
if dark energy interacts with BHs to release their "information"
if dark energy increases

then dark energy may possibly increases enough to release this information
in which case, maybe you'd get a flood of degenerate energy.
... see the problem?

Can you support any of these ifs?

Now you seem to be thinking of dark energy as some sort of magic anti-gravity.
Perhaps you mean one of these:

There are some very speculative ideas about the future of the universe. One suggests that phantom energy causes divergent expansion, which would imply that the effective force of dark energy continues growing until it dominates all other forces in the universe. Under this scenario, dark energy would ultimately tear apart all gravitationally bound structures, including galaxies and solar systems, and eventually overcome the electrical and nuclear forces to tear apart atoms themselves, ending the universe in a "Big Rip". On the other hand, dark energy might dissipate with time, or even become attractive. Such uncertainties leave open the possibility that gravity might yet rule the day and lead to a universe that contracts in on itself in a "Big Crunch". Some scenarios, such as the cyclic model suggest this could be the case. It is also possible the universe may never have an end and continue in its present state forever (see Ludwig Boltzmann#The Second Law as a law of disorder). While these ideas are not supported by observations, they are not ruled out.

... what you have described is a cyclic universe.

 

[DaveC426913]

im not talking about anything beyond the event horizon escaping the gravity of the black hole. I am talking about completely bursting it open with a stronger repulsive energy

This is not science.

See post 15.

Write short replies.

 

[ugalpha]

you sound more like a catholic inquisitor than a science advisor to be honnest.

let me advise you:

Imagination is more important than knowledge
A.E

 

[phinds]

Hey, Dave, I see we've got another live one ... you inquisitor you

 

[ugalpha]

i don't think Dark energy is some magic anti gravity force but I am starting to think most people that posted in my thread have no idea of what a black hole is or dark energy

 

[DaveC426913]

Imagination is more important than knowledge

This is not a board of imagination. It is a board of science.

I don't wish to discourage you from being imaginative, but this is not the place for it.

You agreed to the rules when you signed up:

Overly Speculative Posts:
One of the main goals of PF is to help students learn the current status of physics as practiced by the scientific community; accordingly, Physicsforums.com strives to maintain high standards of academic integrity. There are many open questions in physics, and we welcome discussion on those subjects provided the discussion remains intellectually sound. It is against our Posting Guidelines to discuss, in the PF forums or in blogs, new or non-mainstream theories or ideas that have not been published in professional peer-reviewed journals or are not part of current professional mainstream scientific discussion. Non-mainstream or personal theories will be deleted.

 

[ugalpha]

this is theoretical physics based on a model of the universe with dark energy getting stronger with time. So yes this is science

 

[ugalpha]

also the implications of dark energy on black holes is science

 

[e^(i Pi)+1=0]

http://family.lifegoesstrong.com/sites/default/files/slideshows/images/10131029.jpg

 

[Drakkith]

this is theoretical physics based on a model of the universe with dark energy getting stronger with time. So yes this is science

also the implications of dark energy on black holes is science

The scientific investigation of the effect of dark energy on black holes is science yes. You coming to this forum and posting nonsense and speculation is NOT.

 

[Drakkith]

i don't think Dark energy is some magic anti gravity force but I am starting to think most people that posted in my thread have no idea of what a black hole is or dark energy

You apparently don't know what either of them are. For one, black holes do not "burst open". Second, you cannot, at this time, control, manipulate, or in any way work with any amount of dark energy, let alone an infinite amount of it.

 

[marcus]

Could this liberate all the matter from a black hole?..thought experiment

Hello Ugalpha, welcome to PF, I think you have a legitimate thought experiment that can be a way to learn something about the cosmological constant and/or the different ideas people have about "dark energy".

I don't know anything about you but it seems abstractly speaking like a reasonable question to ask. A person could learn by asking it. I'm not sure I know enough to respond adequately but I will try a little anyway.

So let's say that in my universe Dark energy would get stronger with time.

Could it liberate all the matter stuck in the black hole with suficient repulsive energy?
...

First of all, this is not new. This idea has come up in the professional research literature. That is OK! Ideas for thought experiments do not have to be new. The thing is not how original you are but whether you can learn something by some path of thought.

So people have thought about what would happen if the "dark energy" density was not constant but could change over time. Would it eventually tear apart atoms? Would it eventually tear apart black holes?

IMHO it is a good question because it makes you think about what (in the real world) is at the center of a BH.
I don't mean what is at the center of an idealized theoretical BH according to General Relativity. The idealized GR model is not naturalistic. It has a "singularity" meaning that it breaks down and stops giving meaningful answers.

I mean what is really there? Because if (in thought experiment) you could jack up the cosmological constant until the thing destabilized and dissipated then what would happen would depend on what was really there.

Personally, although I respect the possible pedagogical value of the question, I don't KNOW enough to respond usefully. I don't have any idea what is there in the pit of a BH, really. Is it a new form of matter, of energy? Is it a small chaos of uncertainty? Is it a stew of indefinite geometry? or a state in which geometry and matter are indistinguishable? Personally I have no clue.

Anyway AFAICS it's a constructive thought experiment, so I guess I will think about it a little. I wonder how the Schwarzschild radius depends on Lambda. Or on some other "dark energy" parameter.
Can anyone say? Is anyone reading this thread who knows? Does it depend at all? There have been GR papers about the BH in deSitter space. That would be what one wants. In ordinary non-expanding space the Schw radius is just 2GM/c², so it depends only on the mass and Newton G etc very boring. But in deSitter space,with a Lambda, the BH should look a bit different. and its radius should depend on Lambda, I think. I could be wrong. Anybody?

 

[marcus]

Could this liberate all the matter from a black hole?..thought experiment

OK I found a little something. If anyone reading is more expert and can correct me please do. A quick search came up with this:
http://arxiv.org/pdf/1003.0604v1.pdf
http://arxiv.org/abs/1003.0604

Which says that a black hole cannot exist if its mass exceeds a certain amount depending on one over Lambda.

As you increase Lambda its reciprocal gets less and less it constrains the BH more and more until the BH must cease to exist.

Lambda is the cosmo constant and is our usual handle on what is popularly called "dark energy". It is not clear that "dark energy" as such exists. It is just a way of thinking about Lambda that some people like.
Other people just think of it as another physical constant, like Newton G. Not as an "energy".

But anyway the thought experiment consists of cranking up Lambda to larger and larger levels, and indeed at some point the BH cannot exist.

The formula is very simple if one uses natural units so let us think of G=c=1

and then we have mass and length on the same scale and we can bound the mass of the BH.M < .333 Lamda^-1/2 = 1/(3 √Lambda)

The mass of the BH cannot exceed one over three-times-squareroot-Lambda. So let's say we have a supermassive BH with like a billion solar masses. This corresponds on a length scale to about 1/6000 of a lightyear. Correct me if I'm wrong. Well our present Lambda if you take sqrt inverse corresponds to a length of 9 billion lightyears. So it is too long by a factor of some 54 trillion. That gives an idea of how much we would have to increase Lambda in order to make that particular BH burp itself out of existence.

This is very imprecise. I am neglecting numbers like 3. But anyway. It looks like by increasing the cosmological constant enormously we could make a BH like that begin to burp and gradually DWINDLE in mass and size as we increased Lambda. I don't know what it would look like maybe a great storm of bats, witches hats, and television sets would fly out as it began to give up its existence.

Ugalpha mentioned "information". It might be expected to barf up all the information it had swallowed. But I tremble to speculate what that might look like.

Anyway that's a first installment Ugalpha. Maybe someone else can come up with more specifics. I know a bunch has been written about BH in a universe with Lambda. Not just this one paper. Maybe you can look at the references at the end of this paper and find some earlier ones.

There is also "quintessence". Some professional research literature about some kind of pathological phantom dark energy. I never paid any attention to it. I don't think there is any evidence that Lambda is increasing or that its equation of state is anything but what you would expect for a constant. But you might find out stuff by googling "big rip" and "quintessence" Maybe someone has already studied this very exact thing.

 

[salvestrom]

Oddly enough the charley link in you signature, marcus, very briefly mentions the future state of expansion and mentions it potentially overwhelming the atomic bounds to rip planets apart.

Equally, if all the matter and space in the universe, condensed to a tiny point, which you'd think woud have an even stronger gravitational pull than any black hole yet detected, can still end up being blown apart, then what's to stop a BH suddenly popping open. Potential knew model, where existing black holes, at the end of the universe suddenly burst open and start everything over?

Imagination has driven absolutely everything we have ever done. Don't knock it so readily.