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Author Topic: MASS AND BLACK HOLES  (Read 3501 times)

Offline ukmicky

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MASS AND BLACK HOLES
« on: 02/08/2005 04:23:30 »
If rest mass can create a black hole why can't relativistic mass?

( an object travelling near the speed of light for instance)
« Last Edit: 03/08/2005 02:10:02 by ukmicky »


 

Offline gsmollin

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Re: MASS AND BLACK HOLES
« Reply #1 on: 03/08/2005 03:48:26 »
Well... it can. But remember that the black hole exists in its own local frame. From that frame, there is only rest mass.

However, there are experiments planned where physicists will collide particles in an attempt to create a microscopic black hole. The particles will be moving at nearly c and will have large relativistic masses. When they collide the massive particles may form super-massive particles that collapse into black holes. These holes will evaporate in picoseconds, but their existence would confirm higher dimensional gravitational theories.
 

Dr. Praetoria

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Re: MASS AND BLACK HOLES
« Reply #2 on: 06/08/2005 01:00:24 »
I've heard that a massive nuclear explosion (h-bomb) could create a "blackhole singularity".  Would there be some relationship between such a phenomena and the "creation" of a new galaxy because of the correlation of blackholes at the center of these bodies?
 

Offline David Sparkman

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Re: MASS AND BLACK HOLES
« Reply #3 on: 07/08/2005 04:00:54 »
I don't think we need to worry about a low energy h-bomb causing a black hole. Otherwise the sun would have collapsed upon itself long ago. The energy to form a black hole dwarfs most supernova, in fact, very large supernova are the source of most of the larger black holes. I am not sure about the therorical formation of the smaller ones, but it could make interglactic space travel insurance quite expensive if they are common.

There was a fun novel by Robert Hogan called Thrice upon a time that speculated on forming black holes by the collision of heavy nucelic (Hg), as well as communicating backward in time though the use of positrons (things that behave just like an electron, but with the time axis reversed). I like Hogan's SF because it is only a small stretch from real science as compaired to most of the pop SF of today.

David
 

Dr. Praetoria

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Re: MASS AND BLACK HOLES
« Reply #4 on: 07/08/2005 21:29:17 »
The energy amounts would have to be colossal but I did find that Dr. J. Wheeler did suggest a similar ideas"...ccording to John Wheeler of Princeton University, there is another way: detonating a big hydrogen bomb. He showed that the pressures generated by a suitable explosion could crush matter to the densities needed (around 1017 kilograms per cubic metre) to stand a chance of creating a black hole. However, Wheeler estimated that a "suitable" H-bomb would require all the heavy water in the oceans, and weigh many billions of tonnes." Some bomb
 

Offline Simmer

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Re: MASS AND BLACK HOLES
« Reply #5 on: 08/08/2005 23:09:23 »
I think you missed some zeroes off, 1017 kilograms per cubic metre is less dense that a decent pint of beer!  I've noticed this blind-spot before with you astrophysicists, orders of magnitude mean nothing to people who use giga-suns as a unit of mass! :-)
 

Offline David Sparkman

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Re: MASS AND BLACK HOLES
« Reply #6 on: 09/08/2005 05:13:18 »
I also question the concept as well as the decimal point. The explosive forces of the hydrogen reaction are outward, not inward. Even assuming a simplist model of how a H bomb works, almost all the forces are outward. Super nova's use more energy than exists in the whole earth, and the occasional black hole generated only by the very largest supernova is not caused by the supernova explosion, but rather by the gravitational collapse that comes after the explosion. Most supernova's result in neutron stars, or less. Now a neutron star has some nice exponentials to describe density.

The h-bomb works by creating a temperature of several million degrees inside a sphere of deturium and tridium by using a fission reaction (a-bomb). Hence the a-bomb is pushing outward from inside the fussion bomb. The momentium is mostly outward.
There is compression of the plutonium by the explosive charges (lenses) that will compress the plutonium to roughly twice it's natual density to force it to go crtical, but this is nothing when conpared to a neutron start with roughly a million kg per cc.

David
« Last Edit: 09/08/2005 05:18:57 by David Sparkman »
 

Offline weebrain

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Re: MASS AND BLACK HOLES
« Reply #7 on: 11/08/2005 07:41:03 »
implosion of a star? does that sum it up?


sir loony
 

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Re: MASS AND BLACK HOLES
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