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Q & A: Light from a black hole?

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Most recent answer: 12/15/2013
Q:
I really struggle with this one ! Black holes have such intense gravity that once something goes over the event horizon it cannot escape. That's not to say it has vanished from the universe but it is thought to be irretrievable matter that cannot escape the clutches of black holes. Why then do we see an apparent ejection of material in a quasar. Could it be that the " hole" is actually more like a donut where the core has a substantially less gravitational pull wherein the " inner wall of that donut somehow allows for those particles to escape? I've always been under the impression that NOTHING can escape a black hole so how and why do these ejections exist ?
- Craig (age 63)
Orange City Fl
A:

Hello Craig,

The 'light' that astronomers say is coming from a black hole is really not from the black hole itself but from the 'accretion disk' surrounding it.  As the black hole gobbles up surrounding matter, that matter gets accelerated, becomes very hot, and starts radiating.   So it is essentially the 'death throes' of stars about to be eaten by the black hole.  The resulting bright light that astronomers observe is sometimes called a 'Quasar'.  

See:

 

LeeH

 


(published on 12/15/2013)

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