Question combining - black holes & conservation of angular momentum

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Discussion Overview

The discussion revolves around the relationship between black holes, conservation of angular momentum, and relativistic effects, particularly as they relate to the event horizon and potential implications for dark matter. Participants explore theoretical concepts without a strong mathematical foundation, raising questions about the nature of rotating matter near black holes and the effects of relativistic speeds.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant speculates that as an object approaches the event horizon of a black hole, conservation of angular momentum could accelerate rotating matter to the speed of light, potentially forming an extremely narrow ring.
  • Another participant discusses the idea that centrifugal force, being a manifestation of gravity, might exhibit relativistic effects similar to gravitational forces when taken to extremes.
  • Concerns are raised about the mixing of terms from general relativity, with a participant noting that there is no gravitational force in this framework.
  • There is a suggestion that the conservation of angular momentum could lead to increased rotational speeds in a manner analogous to how mass increases at relativistic speeds.
  • A later reply clarifies the distinction between the angular momentum of a particle near a black hole versus that of a rotating black hole itself, referencing the Kerr solution where the singularity is a ring.
  • One participant expresses a desire for a simpler, non-mathematical explanation of their ideas, indicating a lack of understanding of the relevant mathematics.

Areas of Agreement / Disagreement

Participants do not reach a consensus, as there are multiple competing views regarding the relationship between angular momentum, relativistic effects, and the structure of black holes. Some participants challenge the connections made between concepts, while others propose alternative interpretations.

Contextual Notes

Participants acknowledge limitations in their understanding of the mathematics involved, which may affect the clarity and correctness of their claims. There is also an indication that certain terms and concepts may not relate to one another as suggested.

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had a thought. suspect that i am wrong but not sure where. no idea of the maths involved but suspect As an object approaches the speed of light relativistic forces come into play – effecting time dilation density etc

Can the same theory be rearranged to show that

As you approach the density & time dilation involved at the event horizon of a black hole the conservation of angular momentum would accelerate any rotating matter to the speed of light?
If this is true could the event horizon of a black hole become an extremely narrow ring? Circling its own common center of gravity – material approaching the speed of light at the same time that it forms an event horizon?

If an object of this type existed could they reach galactic sizes ?

Could its diameter, density, rotation, frame dragging of such an object account for the observed effects associated with dark matter ?
 
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ouch :)
i said " no idea of the maths involved " at the start also meaning no understanding of them.

heard a few times from reputable audiobooks that the centrifugal force is indistinguishable from the force of gravity. i have taken this to also mean another manifestation of the same force.

being a manifestation of gravity the centrifugal force should relativistic effects when taken to extremes identical to gravity.

The conservation of angular momentum force is inseparable from the centrifugal force

i was also thinking of the conservation of angular momentum increasing rotation in the same way that any mass is increased with speed is increased. with diverging relativistic effects.

I suspected that the centrifugal forces pulling out and the gravitational forces pulling in could converge forcing such collapsing matter into an extremely narrow ring.
Possibly to the point of a narrow stream of orbiting particles, maybe described as a ring of singularity

the comment about frame dragging was a thought that if such a ring was created the space within that ring could become a frame dragged disc of spacethanks for the reply but if possible is there a simpler non mathematical explanation of if/where i am wrong
 
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I accidentally deleted my post whilst trying to edit it, sorry about that. Regardless, PeterDonis has an excellent blog post related to centrifugal forces in the Schwarzschild geometry (specifically, near Schwarzschild black holes) that may be of use to you: https://www.physicsforums.com/blog.php?b=4327

The problem is that when it comes to topics like this it is near impossible to correctly and comprehensively explain things without math. Unfortunately, you are throwing together a bunch of terms from general relativity that don't actually relate to one another in the way you are describing. Also, there is no gravitational force in general relativity.
 
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is where i am wrong:

knowing that mass is increased when approaching relativistic speeds.
and suspecting that rotational speed is increased in the in the same way ( due to centrifugal ) when approaching relativistic mass/density

or relativistic effects not increasing speeds in the same way



suspected that math could be rearranged to do this in a similar way to e=mc2 can be rearranged to something like m=e/c2 with the same meaning

never even seeing the appropriate math before i won't understand it lol
was thinking someone would point out a simple mistake with the concept rather than needing the math
 
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It's quite confusing for me to try to understand what you want to say. Do you mean angular momentum of a *particle* near a black hole, or are you asking about rotating black hole itself? It seems to me like that latter case from your description. If so, a rotating black hole is described by the Kerr solution in general relativity. The singularity is a ring instead of a point. The black hole itself is like an oblate sphere. Does that help?

See e.g. http://www.daviddarling.info/encyclopedia/K/Kerr_black_hole.html.
 
WannabeNewton said:
The problem is that when it comes to topics like this it is near impossible to correctly and comprehensively explain things without math. .

Here's lots of math for you :-p It's a very recent preprint, in case you missed it.
http://arxiv.org/abs/1306.1019v1
 

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