Black Hole Mass Flows: Is the Balance 0%?

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    Black hole Hole Mass
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Discussion Overview

The discussion revolves around the mass-energy balance of black holes, specifically examining the contributions of various forms of energy loss, such as radiation from the accretion disk, Hawking radiation, and relativistic jets. The scope includes theoretical considerations regarding black hole dynamics and mass flow.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant proposes a breakdown of mass falling into a black hole, suggesting that the total mass can be balanced by the mass-energy equivalents radiated away, leading to a final balance of zero.
  • Another participant agrees with the initial breakdown but notes that it would apply primarily to small black holes, emphasizing that the energy radiated from the disk and jets does not originate from within the black hole itself.
  • A further comment suggests that if a black hole runs out of sufficient mass to sustain itself, it should eventually die off, raising questions about the longevity of black holes based on their mass intake.
  • Another participant acknowledges that while black holes can eventually evaporate, the process of Hawking radiation occurs very slowly, indicating that only small black holes can evaporate significantly through this mechanism.

Areas of Agreement / Disagreement

Participants generally agree on the idea that black holes can lose mass through various forms of radiation, but there is no consensus on the implications for black hole longevity or the specifics of the mass-energy balance, particularly regarding the size of the black hole.

Contextual Notes

The discussion does not resolve the assumptions regarding the conditions under which the mass-energy balance holds true, nor does it clarify the definitions of the terms used in the breakdown. The relationship between the size of the black hole and its ability to sustain itself remains ambiguous.

Islam Hassan
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Is the following breakdown possible with respect to the matter falling into a black hole:

+ Total Mass falling into BH per unit time 100%

- Mass-energy equivalent radiated from accretion disk -X%
- Mass-energy equivalent radiated as Hawking radiation -Y%
- Mass-energy equivalent ejected in relativistic jet -Z%

= Nil final mass-energy balance = 0%
 
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Yeah, sure.
It would have to be a small BH though.
And keep in mind that the energy radiated from the disk and jets is not energy from inside the BH.
 
zhermes said:
Yeah, sure.
It would have to be a small BH though.
And keep in mind that the energy radiated from the disk and jets is not energy from inside the BH.

In that case a BH should die off as soon as there is no more sufficient mass to feed/sustain it, no?

IH
 
Eventually, yes. But the emission of hawking radiation only radiates energy very slowly. Only very small BHs can evaporate this way.
 

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