An article on the Daily Galaxy blog, reports that the spin of super massive black holes is faster than it has ever been in the history of the universe.
First off, you have to admit like I did that this stuff about rotational dynamics of a Kerr or Kerr-Neuman singularity and the loss of angular velocity through energy conversion at the ergosphere/event horizon interface really does make my brain go tilt. Because here is one group that say that the spin collected from the parent star as it collapsed was transferred to the black hole and can be measured at the event horizon (wait, don't call me in it yet). But that spin should be bled off by the ergosphere much like applying disk breaks in a car. Ok, I'll buy that. But then we have to be honest with ourselves when we say black hole and really mean the event horizon. Because the event horizon is in some respect arbitrary in a relative kind of way, because there really isn't anything AT the event horizon. So being honest we are saying that "nothing" can have spin. (no I am not being flip, I know this "nothing" would kill me before I got within a handful of light years from it.)
Ok so this spin is being siphoned off, but in reality will never reach zero. But before that limit is reached where no more energy can be extracted, the black hole converts from a Kerr / Neuman black hole to a Schwarzschild black hole.
Ok so far? So now two UK astronomers have found that the supermassive black holes in the centers of galaxies are on average spinning faster! (HUH? Oh come ON! ) Yep, faster than they ever have in the past 13 odd billion years of the universe's existence. DR. Martinez-Sansigre and Prof. Rawlings say that black holes had very low spins at first (That leaves out the star's rotational energy unless that is what they consider slow...) and adding mass from the accretion disk wouldn't add either. But merging super massive black holes would add significantly to their spin.
Hummmm ok, so Martinez-Sansigre and Rawlings say that they are spinning up, where as papers like this wikipedia article for all intents is saying the more the mass the harder the breaks are applied.
Check them both out and let me know what you people think.
First off, you have to admit like I did that this stuff about rotational dynamics of a Kerr or Kerr-Neuman singularity and the loss of angular velocity through energy conversion at the ergosphere/event horizon interface really does make my brain go tilt. Because here is one group that say that the spin collected from the parent star as it collapsed was transferred to the black hole and can be measured at the event horizon (wait, don't call me in it yet). But that spin should be bled off by the ergosphere much like applying disk breaks in a car. Ok, I'll buy that. But then we have to be honest with ourselves when we say black hole and really mean the event horizon. Because the event horizon is in some respect arbitrary in a relative kind of way, because there really isn't anything AT the event horizon. So being honest we are saying that "nothing" can have spin. (no I am not being flip, I know this "nothing" would kill me before I got within a handful of light years from it.)
Ok so this spin is being siphoned off, but in reality will never reach zero. But before that limit is reached where no more energy can be extracted, the black hole converts from a Kerr / Neuman black hole to a Schwarzschild black hole.
Ok so far? So now two UK astronomers have found that the supermassive black holes in the centers of galaxies are on average spinning faster! (HUH? Oh come ON! ) Yep, faster than they ever have in the past 13 odd billion years of the universe's existence. DR. Martinez-Sansigre and Prof. Rawlings say that black holes had very low spins at first (That leaves out the star's rotational energy unless that is what they consider slow...) and adding mass from the accretion disk wouldn't add either. But merging super massive black holes would add significantly to their spin.
Hummmm ok, so Martinez-Sansigre and Rawlings say that they are spinning up, where as papers like this wikipedia article for all intents is saying the more the mass the harder the breaks are applied.
Check them both out and let me know what you people think.
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