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Little red dots are my favorite new concept in astrophysics. This idea that there could be so much matter orbiting a black hole that the matter reaches sun leve

Little red dots are my favorite new concept in astrophysics. This idea that there could be so much matter orbiting a black hole that the matter reaches sun levels of pressure which in turn starts steller fission without there being an star. Mind-blowing

stouset 4mo ago
Yep, it’s a super cool concept. A black hole of a given size has a finite amount of matter that it can ingest over a period of time. Trying to stuff more matter into it causes an outward pressure from essentially the friction of the swirling mass of material falling in. This radiation pressure could in theory be great enough to start fusion as would happen in a stellar core. Also fun is that this puts a limit on the largest possible black hole we should ever see in the universe. If you assume a black hole formed a moment after matter condensed and then ingested the maximum possible from then until now, you get an upper bound for the largest possible black hole according to our current understanding of the universe. This limit is somewhere around 36 billion solar masses.
- technotony 4mo ago
  Couldn't those large black holes merge though to get bigger ones?
  - muvlon 4mo ago
    Yes, exactly. Black hole mergers are the one thing exempt from the Eddington Limit, because there is no friction there.
- rolph 4mo ago
  a tokomok involving a scale appropriate blackhole is a super cool concept that just came to mind
- thecommakozzi 4mo ago
  [dead]
lenkite 4mo ago
Will all matter in the universe just collapse into black-holes eventually ? It feels that way. And will all the black-holes then merge to form the Primordial Black Hole which will then explode to form a new universe ?
- Larrikin 4mo ago
  All of the evidence currently points the universe expanding and bringing everything further apart. There is no evidence of a cycle. However, some people are starting to believe the expansion is slowing.

stouset 4mo ago

Yep, it’s a super cool concept. A black hole of a given size has a finite amount of matter that it can ingest over a period of time. Trying to stuff more matter into it causes an outward pressure from essentially the friction of the swirling mass of material falling in. This radiation pressure could in theory be great enough to start fusion as would happen in a stellar core. Also fun is that this puts a limit on the largest possible black hole we should ever see in the universe. If you assume a black hole formed a moment after matter condensed and then ingested the maximum possible from then until now, you get an upper bound for the largest possible black hole according to our current understanding of the universe. This limit is somewhere around 36 billion solar masses.

technotony 4mo ago
Couldn't those large black holes merge though to get bigger ones?
- muvlon 4mo ago
  Yes, exactly. Black hole mergers are the one thing exempt from the Eddington Limit, because there is no friction there.
rolph 4mo ago
a tokomok involving a scale appropriate blackhole is a super cool concept that just came to mind
thecommakozzi 4mo ago
[dead]

lenkite 4mo ago

Will all matter in the universe just collapse into black-holes eventually ? It feels that way. And will all the black-holes then merge to form the Primordial Black Hole which will then explode to form a new universe ?

Larrikin 4mo ago
All of the evidence currently points the universe expanding and bringing everything further apart. There is no evidence of a cycle. However, some people are starting to believe the expansion is slowing.