Are Black Holes Matter Sprinklers?

AI Thread Summary
The discussion centers on whether black holes emit more mass through jets than they absorb from surrounding gas disks. It concludes that the total mass emitted by black holes is likely smaller than the mass they pull in, primarily due to thermal radiation and the dynamics of accretion disks. While some energy conversion processes, like nuclear fusion, may occur, they do not significantly contribute to mass output. The jets are formed from matter that misses falling into the black hole, propelled by magnetic fields rather than originating from the black hole itself. Overall, the net mass-energy balance suggests that black holes are not "matter sprinklers," as they do not create mass but rather lose mass over time through various processes.
Rami.Rom
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Is the total jets mass emitted by a black hole to space smaller or larger than the total mass the black hole pulls in from the flat disk of gas that swirls around it?

In other words, are black holes matter sprinklers that convert heat to matter and spray it to space?
 
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Rami.Rom said:
Is the total jets mass emitted by a black hole to space smaller or larger than the total mass the black hole pulls in from the flat disk of gas that swirls around it?

Smaller. The heat is radiated away primarily via thermal emission. It is possible for some nuclear fusion to take place in the accretion disk, in which case some of that energy could be converted to mass. (See: https://www.physicsforums.com/showthread.php?t=452245). It's almost certain, though, that the net mass will decrease.
 
Nothing comes out of a black hole except Hawking radiation...after the cosmic background radiation gets cooler than the black hole...eons from now...Jet's are exterior phenomena.

Black holes are the ultimate roach motel "You can check in, but you can't check out"
 
"Smaller. The heat is radiated away primarily via thermal emission. It is possible for some nuclear fusion to take place in the accretion disk, in which case some of that energy could be converted to mass. (See: https://www.physicsforums.com/showthread.php?t=452245). It's almost certain, though, that the net mass will decrease."

I understand that you estimate that the net mass will be smaller, but do you base your answer on a known proven theory or measurements or is it based on physical intuition?

Do we know for example what is the temperature of these jets at their origin, and what process creates these extremely energetic jets with particle velocities close to the speed of light?

The mass in the universe is much bigger than estimated by the big bang theories and it has to be created somewhere, do we know other physical processes that create mass?
 
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Ok I need to clarify. No energy is being created in any way from a black hole. There is nowhere that is creating mass, or equivalently, energy. The jets from the black holes result from accreting matter being blown out away long the axis of rotation (I'm being purposefully imprecise here. I'm not too terribly familiar with the phenomenon, and I'm not entirely certain even the experts have reached a conclusion) -- i.e. the phenomenon is completely external to the event horizon of the hole. It could equally well happen around a neutron star. So the only thing that is happening is matter falls in, gains kinetic energy, heats up and radiates through accretion, and then is blown out at high velocities poleward -- all a result of the potential energy the matter had before falling in.

While what I said before was based on physical intuition rather than calculations, I am almost certain it is true. The fact is that a large proportion of infalling matter will fall past the event horizon, and this alone is likely enough to compensate for any nuclear fusion that takes place and may spew out mass via the jets. At any rate, the net mass-energy of the infalling matter will decrease as some of it will ultimately be transmitted to the black hole or radiated away.
 
Dear Nabeshin,

The hypothesis is that the black hole is heating the falling matter to extremely high temperatures, particle anti-particle pairs are created and at the event horizon of the black hole the pairs are splitted, anti-particles falls in and particles are injected to space (Hawking radiation). The temperature might be so high that nuclear fusion may occur and heavy atoms may also be created and injected to space by the energetic particle jets. Thus, black holes may convert heat to matter and fill space with the created matter if mass-energy ballance of these processes allow it to occur.
Do you think this scenario is feasible or maybe it contradicts a known physical law?
 
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Mass-Energy Balance of Black Holes

Is the total jets mass emitted by a black hole to space (including hawking radiation) smaller or larger than the total mass the black hole pulls in from the flat disk of gas that swirls around the center of the active galactic nucleus?

In other words, can black holes convert heat to matter and spray it to space?
 


The mass of a black hole includes the sum of all the mass-energy that has fallen into it. This includes mass-energy in every form, including the rest energy of particles and heat.
 


The mass and energy of the jets from a black holes poles don't have to equal the black holes mass. In fact it would be very unlikely for this to occur by chance. It all depends on how much gas/plasma gets pulled towards the black hole and forms an accretion disk. The jets don't really have anything to do with Hawking radiation. As the gas and plasma gets pulled into the black hole the magnetic field lines get all twisted, and when this happens it brings about the existence of the black holes polar jets. The jets come from the accretion disk, and not the black hole itself.

However by the time that a black hole evaporates the total Hawking radiation from the entire life of the black hole will have equaled the mass of the black hole.
 
  • #10


My question is the following, if we will calculate the amount of mass falling in and compare it to the amount of mass thrown out by the jets through a large radius spherical surface that surrounds the active galactic nucleus (AGN) that includes a massive black hole, will we get more matter falling in or more matter thrown out to space?

If we get in this calculation more matter thrown out by the jets to space than falling in, AGN's are sources of matter that may fill space even now, and do not depend on the big bang theory as the only source of matter of the entire universe, am I right?
 
  • #11


Can anyone suggest a calculation, or suggest a guideline for such calculation, that will answer the mass - energy balance question, is the total mass falling into an AGN bigger or smaller comparing to the total mass thrown out by the observed particle jets?
 
  • #13


Thanks!

A relevant paper by Reva Kay Williams describes how Penrose processes can generate high energy e-e+ pairs but it does not try to estimate the total mass of the jets and does not try to compare it to the total infalling mass from the accertion disk.

"Collimated escaping vortical polar e-e+ jets intrinsically produced by rotating black holes and Penrose processes". The Astrophysical Journal, 611, 952-963. (http://arxiv.org/abs/astro-ph/0404135)
Retrieved from "http://en.wikipedia.org/wiki/Relativistic_jet"
 
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  • #14


Rami.Rom said:
Can anyone suggest a calculation, or suggest a guideline for such calculation, that will answer the mass - energy balance question, is the total mass falling into an AGN bigger or smaller comparing to the total mass thrown out by the observed particle jets?

is it an open issue with no answer yet?
 
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  • #15
General Relativity and the AGNs particles jets

Can general relativity theory be used to answer the following question - is the total mass falling into an AGN black hole bigger or smaller comparing to the total mass thrown out by the AGN relativistic particles jets?
 
  • #16


I think so. Since the spacetime is asymptotically flat, the ADM and Bondi masses are conserved. It doesn't matter whether you use ADM or Bondi, because gravitational radiation is negligible. Since the mass of the black hole can only increase, not decrease, it follows that the net mass emitted has to be less than the net mass infalling.
 
  • #17


What about Hawking radiation that decreases the black hole mass and possibly the conversion of heat to matter close the the black hole event horizon where spacetime is curved and particles may be created and where the temperature is extremely high due to the infalling matter from the accertion disks?
 
  • #18
Hawking Radiation and AGN's Jets

Can field theory in curved space and Hawking radiation processes be used to answer the following question - is the total mass falling into an AGN black hole bigger or smaller comparing to the total mass thrown out by the AGN relativistic particles jets?
Thanks,
Rami.
 
  • #19


Hawking radiation has never been observed, and is not responsible for AGN jets. The jets are not well understood, but the assumption is that a portion of the infalling matter is somehow grabbed by the magnetic field surrounding the hole and accelerated out along the poles.
 
  • #20


Rami.Rom, this gets confusing because you simultaneously posted the same question to two different threads. Let me repeat my answer.. Hawking radiation is an extremely small effect, important only in the last few moments of a black hole's existence, once the mass has become small. It has never been observed, and plays no role whatsoever in supermassive black holes, including AGN jets.
 
  • #21


Yeah, AGN jets aren't stuff LEAVING a hole, it's stuff which JUST MISSED the hole and wound up being flung outwards.
 
  • #22


I am looking for a different answer which is:
we do not know, the system is too complex, too many parameters are unknown and a detailed calculation of how much matter falls in and how much matter is thrown out with different temperaure of the AGN and taking into account the curved spacetime and the possibility that matter can be created by the field has never been done.
What do you think?
 
  • #23


>.>

Hmmm, that's starting to sound dangerously like some of those electric universe thunderbolt cranks there... hopefully that's just an odd coincidence?


We can model these systems pretty well actually, but I'm not sure where you're going with "the possibility that matter can be created by the field" part?

http://www.sciencedaily.com/releases/2010/11/101118124212.htm
http://www.sciencedaily.com/releases/2011/03/110302171322.htm

This is right on topic actually: http://www.sciencedaily.com/releases/2011/03/110324153753.htm

This is the first time that magnetic fields have been identified so close to a black hole. Most importantly, Integral shows they are highly structured magnetic fields that are forming an escape tunnel for some of the doomed particles.

Philippe Laurent, CEA Saclay, France, and colleagues made the discovery by studying the nearby black hole, Cygnus X-1, which is ripping a companion star to pieces and feeding on its gas.

Their evidence points to the magnetic field being strong enough to tear away particles from the black hole's gravitational clutches and funnel them outwards, creating jets of matter that shoot into space. The particles in these jets are being drawn into spiral trajectories as they climb the magnetic field to freedom and this is affecting a property of their gamma-ray light known as polarisation.

A gamma ray, like ordinary light, is a kind of wave and the orientation of the wave is known as its polarisation. When a fast particle spirals in a magnetic field it produces a kind of light, known as synchrotron emission, which displays a characteristic pattern of polarisation. It is this polarisation that the team have found in the gamma rays. It was a difficult observation to make.
 
  • #24


Thanks for the pointer. Please note the two quotes from the article -

"Vast storms of particles are falling to their doom at close to the speed of light, raising the temperature to millions of degrees."

and

"We still do not know exactly how the infalling matter is turned into the jets. There is a big debate among theoreticians; these observations will help them decide," says Laurent.

With temperature of millions of degrees nuclear reaction may occur and in addition according to field theory in curved space, particles may be created in strongly curved space close to a black hole and taking these effects into account is not simple.
I guess that no detailed calculation had been done that can tell us how much matter is thrown out in the jets comparing to the matter that falls in. I think it is not a trivial question and my intuition tells me that maybe more matter is thrown out!
 
  • #25


This thread has been merged together from four different threads on basically the same topic. I'm too lazy today to remove the duplicate question posts.
 
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  • #26
Rami.Rom said:
With temperature of millions of degrees nuclear reaction may occur and in addition according to field theory in curved space, particles may be created in strongly curved space close to a black hole and taking these effects into account is not simple.
I guess that no detailed calculation had been done that can tell us how much matter is thrown out in the jets comparing to the matter that falls in. I think it is not a trivial question and my intuition tells me that maybe more matter is thrown out!
The creation of particles in curved space-time does not violate conservation of local stress-energy-momentum (SEM). If the AGN is in a steady state (i.e., the SEM of the accretion disc, black hole, infalling, and jet constituents is constant) then, by definition, the amount of SEM leaving a given region containing the black hole and accretion disc must equal the SEM that is entering the region. Otherwise SEM conservation would be violated (and the correspondence principle would not hold).

So, over very long time periods (and with suitable averaging of any periodic processes so that the conditions described above apply) it is impossible for more SEM to leave an AGN via the jets than enters via infalling SEM (no detailed calculations of the internal dynamics or source of the jets is required to arrive at this conclusion).
 
  • #27
I am not familiar with the steady state approximation applied to an AGN system that includes a black hole, infalling matter from accertion disk and outgoing matter by the jets. Can you send me a reference for such estimation/calculation?
Thanks,
Rami.
 
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  • #28
Rami.Rom said:
I am not familiar with the steady state approximation applied to an AGN system that includes a black hole, infalling matter from accertion disk and outgoing matter by the jets. Can you send me a reference for such estimation/calculation?
To be honest, I just assumed such a scenario was possible given the right assumptions. If the black hole and accretion disc are not growing, and if SEM is not accumulating elsewhere in the region of interest conservation of energy requires the rate of SEM infalling match the rate it is expelled from that region by jets.

However, I found a http://arxiv.org/pdf/1103.0548" that may support these assumptions. It indicates that jets may lead black hole growth to be minimized. Since the amount of infalling SEM is finite, if the rate is approximately constant over a given time period, the accretion disc will settle into equilibrium with about as much leaving via the jets as is impinging onto it. This would lead to the conditions assumed previously.
 
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  • #29
Thanks, the paper is interesting and it shows that the energy balance and the processes that occur at AGNs are not understood very well. Since the paper describes periodic outbursts of energy from the AGNs, maybe they operate like a heat engines and it would be nice if under some physical condition the total mass expelled from the AGNs heat engines would be higher than the total mass falling in.
 
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  • #30
Hawking radiation consists of photons, not particles.
 

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