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Re: Record-breaking supermassive black hole found in heart of far-off galaxy

Cross-posted to 3 groups.

Followups directed to: sci.physics.relativity

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Mike Duffy wrote:

> On Fri, 12 Feb 2016 10:26:28 -0600, Odd Bodkin wrote:
>> Note, John Sefton, that black holes are not presented in GR as things
>> that swallow everything in their vicinity, and that star formation in
>> the region outside a black hole is perfectly consistent with general
>> relativity.
> 
> How does that work?

Very simple.  An object has to *pass* the event horizon of a black hole in 
order to be “swallowed” by it.  That does not happen if the object is far 
enough away from the event horizon and/or has an orbital speed that is high 
enough.  For example, light can circulate forever around a black hole on a 
trajectory outside the event horizon called the “photon sphere”.

Popular-scientific version: <https://www.youtube.com/watch?v=eI9CvipHl_c>
Corresponding science: <http://jila.colorado.edu/~ajsh/insidebh/>

> My limited understanding of the mechanism for black holes emitting matter
> via 'Hawking' radiation works best for black holes just barely big enough
> to hold thenselves together. Bigger ones would thus emit less.

Hawking radiation – which AFAIK is yet to be detected – has nothing to do 
with this.

<https://en.wikipedia.org/wiki/Hawking_radiation>


X-Post & F'up2 <news:sci.physics.relativity>

PointedEars
-- 
Q: Who's on the case when the electricity goes out?  
A: Sherlock Ohms.

(from: WolframAlpha)

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Record-breaking supermassive black hole found in heart of far-off galaxy Yousuf Khan <bbbl67@spammenot.yahoo.com> - 2016-02-12 11:21 -0500
  Re: Record-breaking supermassive black hole found in heart of far-off galaxy Odd Bodkin <bodkinodd@gmail.com> - 2016-02-12 10:26 -0600
    Re: Record-breaking supermassive black hole found in heart of far-off galaxy Mike Duffy <Invalid@no_such_domain.com> - 2016-02-12 11:56 -0500
      Re: Record-breaking supermassive black hole found in heart of far-off galaxy Odd Bodkin <bodkinodd@gmail.com> - 2016-02-12 11:09 -0600
      Re: Record-breaking supermassive black hole found in heart of far-off galaxy Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2016-02-13 01:37 +0100
  Re: Record-breaking supermassive black hole found in heart of far-off galaxy Sam Wormley <swormley1@gmail.com> - 2016-02-12 11:02 -0600

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