Can black holes convert matter/dark matter?

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Discussion Overview

The discussion revolves around whether black holes can convert dark matter into normal matter and vice versa. Participants explore the nature of black holes, the composition of Hawking radiation, and the properties of dark matter, touching on theoretical implications and the limitations of current understanding in physics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants propose that black holes can gain mass from normal matter, dark matter, or light, and question if Hawking radiation includes particles from these sources.
  • Others argue that Hawking radiation is not composed of particles but is electromagnetic radiation, leading to a debate about the nature of this radiation.
  • There is uncertainty regarding whether a black hole made of matter is the same as one made of dark matter, with some suggesting that dark matter could possess a "dark charge" affecting the black hole's metric.
  • Some participants express skepticism about the current understanding of dark matter and the internal workings of black holes, noting that General Relativity does not clarify the nature of dark matter.
  • A later reply emphasizes that the evidence for dark matter is based on gravitational effects rather than direct detection, suggesting it behaves like regular matter in terms of gravity.
  • Participants discuss the thermal nature of Hawking radiation, with some asserting that stellar-mass black holes emit radiation similar to a black body at very low temperatures, which complicates the production of massive particles.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the nature of Hawking radiation or the properties of dark matter in relation to black holes. Multiple competing views remain, particularly regarding the conversion of dark matter and the implications of black hole metrics.

Contextual Notes

There are limitations in the discussion regarding the assumptions made about dark matter and the singularity predicted by General Relativity, which some participants question. The discussion reflects ongoing uncertainties in the field.

Khashishi
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Can black holes convert dark matter into matter and vice versa?

Presumably, a black hole can gain its mass from eating normal matter, or dark matter, or light. Then, it will eventually evaporate into Hawking radiation. I guess the Hawking radiation should include light as well as both matter and dark matter particles.

Is a black hole made of matter exactly the same as a black hole made of dark matter? Could dark matter possesses a "dark charge" which alters the black hole metric analogous to the Reissner-Nordstrom metric?
 
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Khashishi said:
Can black holes convert dark matter into matter and vice versa?
no, stuff just falls in.

Presumably, a black hole can gain its mass from eating normal matter, or dark matter, or light.
yes
Then, it will eventually evaporate into Hawking radiation.
yes
I guess the Hawking radiation should include light as well as both matter and dark matter particles
No, Hawking radiation is not particles it is electromagnetic radiation.

Is a black hole made of matter exactly the same as a black hole made of dark matter?
Yes, you can't tell any difference at all.
 
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phinds said:
No, Hawking radiation is not particles it is electromagnetic radiation.
Oh? I thought it was a thermal mix of all particles. Photons just happen to be the most likely, due to having zero mass.
 
I don't think anyone knows what dark matter is or what really happens inside a black hole. General Relativity is the usual model that is used for black holes but it is silent about what constitutes dark matter. Also GR predicts a singularity in the black hole but I don't think anyone seriously believes that this is physically the case.

Cheers
 
cosmik debris said:
I don't think anyone knows what dark matter is or what really happens inside a black hole. General Relativity is the usual model that is used for black holes but it is silent about what constitutes dark matter. Also GR predicts a singularity in the black hole but I don't think anyone seriously believes that this is physically the case.

Cheers
We all know what really goes on in those Black Holes
tesseract.jpg
 
Khashishi said:
Is a black hole made of matter exactly the same as a black hole made of dark matter? Could dark matter possesses a "dark charge" which alters the black hole metric analogous to the Reissner-Nordstrom metric?
We don't know for sure what the stuff is, so we can't make authoritative pronouncements about its properties.

But seeing as how the evidence for its existence is observation of gravitational effects consistent with there being more mass in some volumes of space than is accounted for by the matter that we can see... The simplest and most obvious hypothesis is that it gravitates just like all other matter, and what makes it "dark" is just that it's not readily detectably through any of our traditional methods.
 
phinds said:
No, Hawking radiation is not particles it is electromagnetic radiation.
Khashishi said:
Oh? I thought it was a thermal mix of all particles. Photons just happen to be the most likely, due to having zero mass.
Khashishi is right...

Although for a stellar-mass black hole "most likely" is an huge enormous understatement. These things are radiating like a black body just barely above zero degrees Kelvin, and that's nowhere near energetic enough to have any discernible probability of producing massive particles. It gets more exciting with much smaller and hotter black holes.
 
Last edited:
Nugatory said:
Khashishi is right...
Thanks for that correction.
 

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