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Re:event horizon.

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[It should be noted that, sadly, Stephen W. Hawking died this morning
 at the age of 76, which might have caused the question to be posted.]

Libor Striz wrote:

> Simon Roberts <retenshun@gmail.com> Wrote in message:
>> event horizon.
>> 
>> What happens when the event horizon's radius becomes smaller than its
>> black hole?
> 
> See evaporation of black holes by the Hawking radiation. This
>  radiation progressively increases with the BH mass decreasing,
>  ending with a big shower of particles.

You should be more specific.

The *temperature* of the radiation should be progressively increasing:

  T_H = ℏ c³∕(8π G M k_B).
 
Therefore the *luminosity*

  P = Aₛ ε σ T_H⁴ = ℏ c⁶∕(15360 π G² M²).

  Aₛ = 4 π rₛ²     Schwarzschild surface
  rₛ = 2 G M∕c²    Schwarzschild radius

  G – Newton’s gravitational constant
  M – mass of black hole
  c – speed of light in vacuum
  ε – emissivity
  σ – Stefan–Boltzmann constant

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

> For usual BH masses, this process is extremely slow even if
>  compared to the supposed universe age.

While your answer makes sense, the question is just word salad.

A (non-rotating) black hole is *defined* as the spherical region surrounding 
a spacetime singularity, whose radius is that of the (outer) event horizon.  
So the “event horizon's radius” cannot “[become] smaller than its black 
hole”.

<https://en.wikipedia.org/wiki/Event_horizon#Event_horizon_of_a_black_hole>

Instead, evaporation is precisely the process where the black hole loses 
mass by emitting Hawking radiation, so that the radius of its event horizon 
shrinks *accordingly*, and the black hole *becomes* *smaller* as a result.

<http://jila.colorado.edu/~ajsh/bh/singularity.html#r=1>


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

(from: WolframAlpha)

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event horizon. Simon Roberts <retenshun@gmail.com> - 2018-03-13 23:32 -0700
  Re:event horizon. Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-03-14 08:14 +0100
    Re: event horizon. mlwozniak@wp.pl - 2018-03-14 00:53 -0700
    Re:event horizon. Térov Balónky <iytn@yeicenlw.ik> - 2018-03-14 15:59 +0000
      Re:event horizon. "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-14 09:19 -0700
    Re:event horizon. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-14 18:18 +0100
  Re: event horizon. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-14 22:15 -0500
    Re: event horizon. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-15 16:29 +0100
      Re: event horizon. Gary Harnagel <hitlong@yahoo.com> - 2018-03-15 09:20 -0700
      Re: event horizon. Térov Balónky <iytn@yeicenlw.ik> - 2018-03-16 14:48 +0000
      Re: event horizon. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-19 10:36 -0500
        Re: event horizon. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-20 00:56 +0100
          Re: event horizon. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-20 14:13 -0500
            Re: event horizon. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-20 20:56 +0100
              Re: event horizon. Steven Carlip <carlip@physics.ucdavis.edu> - 2018-03-22 09:17 -0700
                Re: event horizon. Darryl Fletcher <lu@ewiwwe.tt> - 2018-03-22 16:37 +0000
                Re: event horizon. Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-22 18:10 +0100
                Re: event horizon. JanPB <filmart@gmail.com> - 2018-03-23 13:13 -0700
                Re: event horizon. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2018-03-22 14:54 -0700
                Re: event horizon. Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-22 23:06 -0700
            Re: event horizon. Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-20 22:51 -0700
              Re: event horizon. Odd Bodkin <bodkinodd@gmail.com> - 2018-03-21 11:37 +0000
                Re: event horizon. Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-22 13:51 -0700
              Re: event horizon. JanPB <filmart@gmail.com> - 2018-03-23 13:31 -0700
                Re: event horizon. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-23 15:59 -0500
                Re: event horizon. Emma Blazer <aemb@wmopswxa.as> - 2018-03-23 22:19 +0000
                Re: event horizon. JanPB <filmart@gmail.com> - 2018-03-23 15:43 -0700
                Re: event horizon. Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-23 22:06 -0700
                Re: event horizon. mlwozniak@wp.pl - 2018-03-23 23:05 -0700
                Re: event horizon. Emma Blazer <aemb@wmopswxa.as> - 2018-03-24 10:55 +0000
    Re: event horizon. JanPB <filmart@gmail.com> - 2018-03-19 20:42 -0700
      Re: event horizon. Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-23 10:37 -0500
    Re: event horizon. Koobee Wublee <koobee.wublee@gmail.com> - 2018-03-20 22:44 -0700
  Re: event horizon. numbernumber1964@gmail.com - 2018-03-20 13:55 -0700
    Re: event horizon. Odd Bodkin <bodkinodd@gmail.com> - 2018-03-20 23:02 +0000
  Re: event horizon. alsor@interia.pl - 2018-03-20 16:12 -0700
  Re: event horizon. numbernumber1964@gmail.com - 2018-03-22 15:24 -0700
    Re: event horizon. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2018-03-22 17:14 -0700
    Re: event horizon. pnalsing@gmail.com - 2018-03-22 17:32 -0700
  Re: event horizon. numbernumber1964@gmail.com - 2018-03-23 10:37 -0700
    Re: event horizon. Prokaryotic Caspase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2018-03-23 13:32 -0700
  Re: event horizon. numbernumber1964@gmail.com - 2018-03-23 10:38 -0700
    Re: event horizon. moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-03-24 01:36 +0000

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