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Post by SM on Mar 5, 2009 18:29:52 GMT -5
If no singularity, then yes.
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Post by The Dark Master on Mar 7, 2009 11:45:44 GMT -5
There are singularities though.
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Post by SM on Mar 8, 2009 12:30:58 GMT -5
No there are not.
A singularity is an infinitely small and infinitely dense object, which cannot exist.
First of all, because D=M/V, and Infinity=X/Infinity, the mass is undefined, and therefore infinite.
This means that the black hole will have infinite gravity regardless of distance. Also it means we will all get pulled in infinitely fast and will all become infinitely dense.
Also, it creates infinite heat. Because heat=expansion, the black hole will expand infinitely, and therefore an infinite amount of matter will be ejected, creating an infinitely large solid mass in the universe expanding at infinite speeds.
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Post by General Veers on Mar 8, 2009 12:36:36 GMT -5
First of all, because D=M/V, and Infinity=X/Infinity, the mass is undefined, and therefore infinite. Actually, the limit of x/z as z approaches infinity is zero, not infinity...so the mass would therefore be undefined without necessarily being infinite. But yes, singularities seem impossible. Ever since The Dark Master brought it up, I've been wanting to read Stephen Hawking's literature. As for infinite gravity... F grav=(GM bhM 2)/r 2...when G=~6.67*10 -11Nm 2kg -2, M bh is the mass of the black hole, M 2 is the mass of whatever entity is being affected by the black hole, and r is the distance between the centers of the two masses. It is also true that F grav=M 2g, where g is the acceleration of gravity (which on Earth would be approximately 9.8ms -2. (GM bhM 2)/r 2=M 2g. (GM bh)/r 2=g For a black hole, its gravitational acceleration at any point would be directly proportional to its mass and inversely proportional to the square of the distace from that point to the center of the black hole. GMbh=gr2
The square of the distance and the gravitational acceleration are both directly proportional to the mass of the black hole. If both mass and distance were infinite, that does not necessarily mean that the gravitational force would be infinite (infinity/infinity 2 indeterminate form conflict).
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Post by SM on Mar 8, 2009 13:08:22 GMT -5
If the mass was 0 then that means that the black hole would fizzle out instantly.
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Post by General Veers on Mar 8, 2009 13:09:31 GMT -5
Which is why singularities wouldn't exist, according to the math that we know...
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Post by The Dark Master on Mar 8, 2009 13:16:20 GMT -5
If singularities didn't exis, how come there are black holes?
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Post by SM on Mar 8, 2009 13:18:46 GMT -5
BECAUSE BLACK HOLES DON'T HAVE SINGULARITIES DAMMIT
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Post by The Dark Master on Mar 8, 2009 13:23:21 GMT -5
Then what would they have?
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Post by General Veers on Mar 8, 2009 13:26:08 GMT -5
Superdense (but still finite) mass, which results in super (but still finite) gravitational forces and what not...
It's a shame I don't have a copy of A Brief History of Time, though...
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Post by The Dark Master on Mar 8, 2009 13:38:00 GMT -5
Well in it i methinks singularities will be explained... You could order it off somewhere or go in a library. Anyway i have now decided that singularities cant be infinitely dense, because where would the infinite mass come from? The imploded star doesnt provide infinite mass or gravity....
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Post by SM on Mar 8, 2009 13:58:21 GMT -5
If they aren't infinitely dense, but infinitely small, then they have no mass and don't exist.
Singularities are a property of special relativity which I believe is false.
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Post by The Dark Master on Mar 8, 2009 14:03:02 GMT -5
If they don't exist, how did the idea of them come about?
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Post by SM on Mar 8, 2009 14:12:18 GMT -5
Because people believe special relativity is true.
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Post by The Dark Master on Mar 8, 2009 14:27:49 GMT -5
Hm. What about general relativity? What does that say about black holes?
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Post by spaghetticat on Mar 8, 2009 18:11:24 GMT -5
You guys are looking at it all wrong. Singularity is just a fancy way of saying the density of the black holes center. Today I was watching a documentary on Supermassive black holes at the center of galaxies. They have discovered that all observable galaxies have supermassive black holes and there are several ratios between the black hole and the galaxy. One ratio is mass of the galaxy to the mass of the black hole. The other is the mass of he black hole to the gravitational force on stars at the edge of the galaxy.
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Post by General Veers on Mar 8, 2009 19:26:20 GMT -5
Indeed have we not been talking about the density of a black hole? And indeed wouldn't any entity of finite volume and finite mass have finite density?
Granted, we haven't necessarily been talking about the center of a black hole, but would that not still have finite mass and finite volume, and therefore finite density? Even if the center was a geometric point of no volume and mass, in which case the density would be indeterminate?
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Post by spaghetticat on Mar 8, 2009 20:35:48 GMT -5
That's just it! Black holes have a finte density but not a finite mass!
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Post by General Veers on Mar 8, 2009 21:26:18 GMT -5
Well, if you take into account that they are constantly pulling in anything within its gravitational field, then you could say that it has infinite mass...but at any one instantaneous moment in time, there is a finite amount of matter composing the black hole, even though that finite amount might change over time...
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Post by spaghetticat on Mar 8, 2009 21:40:53 GMT -5
If something's mass is finite, it's mass cannot increase. That's like saying two times infinity.
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