Posted by
chrisd
on from the infinite-radius-finite-diameter dept.
paradox writes "Reuters is reporting that scientists have found a massive black hole 40,000 light-years away that could change the way scientists think about black holes. The mass of this particular black hole is 14 times the mass of the sun, compared to the typical mass of 3 to 7 suns."
Supermassive black holes
by
ukryule
·
· Score: 4, Interesting
Whatever happened to the theory of supermassive black holes? These black holes, at the centre of each galaxy are supposed to be millions of times heavier than the sun.
So what's so great about a black hole only 14 times as heavy as the sun (which is also further away than the centre of our galaxy)?
yes you can...
by
efuseekay
·
· Score: 5, Interesting
it's called the Penrose process. You use it on a rotating blackhole.
The idea is that in a rotating blackhole, the minimum point of the potential moves around, so you can actually "slows" the blackhole while getting a nice angular momentum kick.
Much like how you use the rotation of jupiter for slingshot. ("gravity assist" is a bad phrase, reality is that it's "angular momentum assist")
-- Mode (3) smart-aleck mode. Press * to return to main menu.
Re:Potential energy source?
by
gilroy
·
· Score: 4, Interesting
Blockquoth the poster:
Assuming Big Bang theory, yadda yadda, the reason the universe expands is because of kinetic energy -- mass moving away from the "big bang".
Actually, the Universe expands because, well, the Universe expands... it's in the nature of the spacetime metric, as one of the solutions to Einstein's equations. It doesn't (necessarily) have anything to do with kinetic energy... it's not that planets, stars, etc., are flying into empty space. It's that space itself is growing larger with time.
Slashdot Mirror
Whatever happened to the theory of supermassive black holes? These black holes, at the centre of each galaxy are supposed to be millions of times heavier than the sun.
So what's so great about a black hole only 14 times as heavy as the sun (which is also further away than the centre of our galaxy)?
it's called the Penrose process. You use it on a rotating blackhole.
The idea is that in a rotating blackhole, the minimum point of the potential moves around, so you can actually "slows" the blackhole while getting a nice angular momentum kick.
Much like how you use the rotation of jupiter for slingshot. ("gravity assist" is a bad phrase, reality is that it's "angular momentum assist")
Mode (3) smart-aleck mode. Press * to return to main menu.
Actually, the Universe expands because, well, the Universe expands... it's in the nature of the spacetime metric, as one of the solutions to Einstein's equations. It doesn't (necessarily) have anything to do with kinetic energy... it's not that planets, stars, etc., are flying into empty space. It's that space itself is growing larger with time.
The Mongrel Dogs Who Teach