Superluminal Gravitational Acceleration

In summary, the conversation discusses the possibility of gravitational attraction from a black hole accelerating an object faster than the speed of light. It is mentioned that this is not possible due to time dilation and the complexities of incorporating an accelerating object into the equation. The conversation also delves into the infalling matter disintegrating into energy and becoming part of the accretion disk, with some of that energy potentially exiting through the accretion jets. The use of the term "disintegrates into energy" is clarified and the debate on the Penrose mechanism as an energy source for black holes is mentioned. The conversation also discusses the form of particles near the event horizon and the temperatures involved.
  • #1
Terdbergler
15
0
Can gravitational attraction (generated by a super-massive black hole, for instance) accelerate you faster than c?
 
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  • #2
No. You can't overtake light.
 
  • #3
That it's impossible to go faster than light is common knowledge. It should be obvious that I'm asking for more information than just that. Does the body reach a terminal velocity in a vacuum? Or will the acceleration itself "decelerate" but never stop? There are a number of ways this could hypothetically play out. I'm asking for the way in which it would actually play out.
 
  • #4
Infalling matter disintegrates into energy and becomes part of the accretion disk. Though not 100% of the infalling material will fall past the EH. Some of that energy may exit via the accretion jets. If you want the complete picture though technical you can find it contained in this lengthy and technical paper. There is a variety of influences on the angular momentum most of which are covered in this paper

http://arxiv.org/abs/1104.5499
 
  • #5
Terdbergler said:
Can gravitational attraction (generated by a super-massive black hole, for instance) accelerate you faster than c?

you can't fault, Bandersnatch's answer considering the question and title you posted lol
 
  • #6
Terdbergler said:
That it's impossible to go faster than light is common knowledge. It should be obvious that I'm asking for more information than just that. Does the body reach a terminal velocity in a vacuum? Or will the acceleration itself "decelerate" but never stop? There are a number of ways this could hypothetically play out. I'm asking for the way in which it would actually play out.

This is actually a little more complicated than you realize. You are talking about incorporating an accelerating object with increasing gravitational time dilation. An observer stationary with respect to the black hole would need to compensate for the time dilation in order to properly calculate the acceleration of the infalling object. I honestly don't know exactly what the observer would "see", so I can't answer your question.

Mordred said:
Infalling matter disintegrates into energy and becomes part of the accretion disk.

I don't think this is very accurate. Infalling matter is heated up within the accretion disk, which does emit radiation, but I wouldn't say it "disintegrates into energy". Matter can and does fall past the event horizon intact.
 
  • #7
Drakkith said:
This is actually a little more complicated than you realize. You are talking about incorporating an accelerating object with increasing gravitational time dilation. An observer stationary with respect to the black hole would need to compensate for the time dilation in order to properly calculate the acceleration of the infalling object. I honestly don't know exactly what the observer would "see", so I can't answer your question.
I don't think this is very accurate. Infalling matter is heated up within the accretion disk, which does emit radiation, but I wouldn't say it "disintegrates into energy". Matter can and does fall past the event horizon intact.

the disintegrates into energy is the terms used in the article, " the disintegration process must convert most of the rest mass energy of the infalling particle to kinetic energy, in the sense that, in the center-of-mass frame, the E particle must have velocity v > c/2. Its under the section described as the Penrose process. Essentially the energy of the particle splits into two particles one positive, and one negative, the negative particle falls in the positive particle escapes to infinity. page 44

though I may have this mistinterpreted for example I'm not sure what they mean by escapes to infinity lol (quantum tunnelling)? I would assume so as its similarity to Hawking radiation cannot be ignored
they do explain after that, a debate on this process

"The Penrose mechanism cannot serve as a useful energy source for astrophysical processes. In no case can one obtain energies which are greater by a signicant factor than those which already could be obtained by a similar breakup process without the presence of the black hole."

though this debate is more in line as to whether or not you can extract energy from a black hole.

so as you say the question is not easily answered
 
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  • #8
Mordred said:
the disintegrates into energy is the terms used in the article, " the disintegration process must convert most of the rest mass energy of the infalling particle to kinetic energy, in the sense that, in the center-of-mass frame, the E particle must have velocity v > c/2. Its under the section described as the Penrose process. Essentially the energy of the particle splits into two particles one positive, and one negative, the negative particle falls in the positive particle escapes to infinity. page 44

Yes, but the penrose process is about stealing angular momentum from the black hole by using the ergosphere, not about the accretion process as a whole. The penrose process does not occur in a non-rotating black hole and is a little beyond the scope of the OP's question.
 
  • #9
ah but my original reply is this

Infalling matter disintegrates into energy and becomes part of the accretion disk. Though not 100% of the infalling material will fall past the EH. Some of that energy may exit via the accretion jets. If you want the complete picture though technical you can find it contained in this lengthy and technical paper. There is a variety of influences on the angular momentum most of which are covered in this paper


you asked for the clarification on the use of the term "disintegrates into energy" let me ask you this in any calculation you've seen near or around the event horizon what form is the particles in? if I'm not mistaken its in the form of photons. ie relativistic. prior to reaching the EH particles reach thermal equilibrium. The temperatures involved are so extreme that hydrogen for example would not be stable. So do we term photons as matter? I chose the dintegrates term as it was used in the literature I provided.


And yes you are correct on the Penrose mechanism, relation to the ergosphere. However mass is already being stripped outside the EH in the region of the ergoshere. Once you remove mass from a particle its obviously not the same particle, which is defined by its mass spin etc. if you strip all the rest mass then and it becomes relativistic its essentially a photon. Now the Penrose process states this photon then decays into a particle pair the negative falls in the positive tunnels out. same with Hawking radiation at the EH itself

edit: in hindsite I should have stated converted to radiation not energy though black holes are often described as the most efficient matter to energy converters in nature next to direct matter-antimatter annihilation's
 
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  • #10
I'm honestly not sure what the paper you linked is saying when they use "particle", as they talk of splitting particles into pieces. (As do other explanations of the Penrose effect I looked at) Perhaps they aren't referring to fundamental particles?
 
  • #11
Yeah they don't specify in this article, any form of virtual particle production I've seen is usually
photons or electrons. However this article specifies electrons due to photon interactions

that's based more on this article

http://arxiv.org/abs/astro-ph/0306135

[tex]\gamma\gamma\rightarrow e^-e^+[/tex]

yay I figured out how to latex this lol, took me a bit
 
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1. What is superluminal gravitational acceleration?

Superluminal gravitational acceleration refers to a hypothetical phenomenon in which an object is accelerated faster than the speed of light due to the influence of gravity.

2. Is superluminal gravitational acceleration possible?

Currently, there is no evidence or scientific theory to support the possibility of superluminal gravitational acceleration. According to Einstein's theory of relativity, nothing can travel faster than the speed of light, including gravitational effects.

3. How is superluminal gravitational acceleration different from regular gravitational acceleration?

Regular gravitational acceleration occurs when an object is pulled towards a massive body, such as the Earth, due to the force of gravity. Superluminal gravitational acceleration, on the other hand, suggests that an object can be accelerated to speeds faster than light due to the influence of gravity.

4. What are the potential implications of superluminal gravitational acceleration?

If superluminal gravitational acceleration were possible, it would challenge our current understanding of physics and the laws of the universe. It could also have significant implications for space travel and the exploration of distant galaxies.

5. Are there any experiments or studies being done on superluminal gravitational acceleration?

Currently, there are no known experiments or studies being conducted on superluminal gravitational acceleration. However, scientists continue to explore and research potential theories and phenomena that could potentially challenge our current understanding of the universe.

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