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Re: Accretion discs

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john <johnsefton288@gmail.com> writes:

> Hawking radiation).  The jets come from the inner accretion disk, not 
> the hole itse"
> 
> And you know this how?
> And how does this accretion disc matter
> get accelerated to .9c?
> Please explain.

Unlike you, astronomers have models of how they believe the universe works.
These models either directly or through computer simulations, show what
should happen given certain initial conditions.  These models predict
acceretion disks around black holes, which are very violent places with
extreme temperatures.

These models and simulations, including the effects of GR and powerful magnetic
fields, then go on to predict that some of the (extreme) kinetic energy of
plasma in the disk expels some of the matter from the disk violently
(~90% of c) at right angles to the disk.  And what we observe seems to match
those predictions quite well.

>Ed
>"
>Do you not understand the conversion of 
> potential to kinetic energy? 
>"
>Which is which? They saw a star orbit
>more and more rapidly around a BH,
>and then it shredded,
>and then jets formed as soon as it shredded.
>Where is the potential and where does it
>convert?

You don't know the difference between potential and kinetic energy? Sheesh.

Pick up a rock and hold it high. It took energy for you to do that.  If
energy is conserved, where did it go? The rock now has potential energy,
it has energy that can do something.  Now let go of the rock. It starts
to fall, to move faster. The motion is kinetic energy.  As it smashes into
your foot, the kinetic energy becomes work it takes to smash your toes. :-)

A star nearish a black hole. It has potential energy that can be released
by falling toward the hole. As it falls toward the hole (not directly but
in some sort of decaying orbit) some of that energy becomes kinetic energy
in the form of the velocity of the star.  The star orbits faster as it gets
closer to the hole.  Like the moon, it takes a month to orbit the earth
but the much closer ISS takes only about 90 minutes to do so.

Separately, go look up "Roche Limit".  As something that is held together
by gravity only (such as the star) gets too close to something more massive,
tidal forces start to tear it apart. You say "shreds".  Doesn't have to be
a black hole, think of the rings of Saturn which may have been from a moon
within Saturn's Roche Limit that got shredded.  (Or at least the Roche Limit
prevents the rings from forming into a new moon).

A star too close to the black hole is tidally disrupted and it, too, forms
rings around it.  Those rings are called an accretion disk.
As the matter in the accretion disk gets squeezed and heated, the jets
form as some of the matter is expelled from it and forms jets.

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Accretion discs john <johnsefton288@gmail.com> - 2017-04-21 17:20 -0700
  Re: Accretion discs poraty350@gmail.com - 2017-04-22 02:03 -0700
    Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-22 07:17 -0700
      Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-22 08:37 -0700
        Re: Accretion discs poraty350@gmail.com - 2017-04-25 03:12 -0700
      Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-22 08:50 -0700
      Re: Accretion discs HVAC <mr.hvac@gmail.com> - 2017-04-22 17:12 -0700
        Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-23 06:12 -0700
          Re: Accretion discs HVAC <mr.hvac@gmail.com> - 2017-04-23 07:28 -0700
            Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-23 10:08 -0700
            Re: Accretion discs benj <nobody@gmail.com> - 2017-04-24 00:35 -0400
          Re: Accretion discs moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-24 21:49 +0000
        Re: Accretion discs benj <nobody@gmail.com> - 2017-04-24 00:24 -0400
    Re: Accretion discs "Kevin Jones" <mapihapimapihapal@gmal.com> - 2017-04-22 08:55 -0700
  Re: Accretion discs "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-04-22 15:17 -0700
    Re: Accretion discs HVAC <Harlowcampbell@gmail.com> - 2017-04-23 11:05 -0400
      Re: Accretion discs benj <nobody@gmail.com> - 2017-04-24 00:36 -0400
        Re: Accretion discs HVAC <mr.hvac@gmail.com> - 2017-04-24 02:16 -0700
          Re: Accretion discs benj <benj@nobody.net> - 2017-04-24 16:11 -0400
            Re: Accretion discs "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-04-24 13:45 -0700
              Re: Accretion discs benj <benj@nobody.net> - 2017-04-24 17:31 -0400
                Re: Accretion discs "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-04-25 11:15 -0700
                Re: Accretion discs "hanson" <hanson@quick.net> - 2017-04-25 12:30 -0700
                Re: Accretion discs benj <benj@nobody.net> - 2017-04-25 18:25 -0400
                Re: Accretion discs HVAC <mr.hvac@gmail.com> - 2017-04-26 02:43 -0700
                Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-26 16:14 -0700
                Re: Accretion discs pnalsing@gmail.com - 2017-04-26 17:25 -0700
                Re: Accretion discs moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-27 02:14 +0000
                Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-27 09:18 -0700
                Re: Accretion discs Edward Prochak <edprochak@gmail.com> - 2017-04-27 09:51 -0700
                Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-27 10:47 -0700
                Re: Accretion discs moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-27 20:18 +0000
                Re: Accretion discs john <johnsefton288@gmail.com> - 2017-04-27 13:46 -0700
                Re: Accretion discs moroney@world.std.spaamtrap.com (Michael Moroney) - 2017-04-28 02:23 +0000
                Re: Accretion discs Edward Prochak <edprochak@gmail.com> - 2017-04-28 10:39 -0700
  Re: Accretion discs "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-04-28 12:21 -0700
    Re: Accretion discs "hanson" <hanson@quick.net> - 2017-04-28 16:05 -0700
    Re: Accretion discs "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-04-30 12:58 -0700
      Re: Accretion discs "hanson" <hanson@quick.net> - 2017-04-30 13:35 -0700
      Re: Accretion discs "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-05-01 10:00 -0700
        Re: Accretion discs "hanson" <hanson@quick.net> - 2017-05-01 12:30 -0700
        Re: Accretion discs "reber G=emc^2" <herbertglazier0@gmail.com> - 2017-05-01 15:36 -0700
          Re: Accretion discs "hanson" <hanson@quick.net> - 2017-05-01 19:53 -0700

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