|MadSci Network: Astronomy|
GLANCING BLOW BETWEEN TWO BLACK HOLES TRAVELING AT HIGH RELATIVE SPEEDS ONE MASSIVE THE OTHER NOT SO MASSIVE...WOULD IT BE POSSIBLE TO UNWIND THE SMALLER OF THE TWO? AT SOME POINT MATTER MUST BE TRAVELING AT THE SPEED OF LIGHT, CREATING ALOT OF MOMENTUM...REACH IN THERE AND PEEL OFF ENOUGH MATTER TO REDUCE THE SMALLER BELOW THE THESHOLD OF BLACKHOLENESS AND LET ALL THAT MATTER ESCAPE?
What makes a black hole a black hole is the very fact that matter cannot escape from it, no matter what. A black hole is an object so dense that in order for anything to escape from it's surface it must go faster than the speed of light. But that is impossible as shown in the theory of special relativity. Nothing can go faster than the speed of light. And matter cannot even travel at the speed of light. It would take an infinite amount of energy to accelerate something to the speed of light. The surface of a black hole is thus called an event horizon because we cannot know about any event that occurs beneath that surface. Therefore two black holes colliding will coalesce into a larger black hole.
There is a quantum mechanical effect that makes a black hole slowly lose mass and energy and eventually evaporate. This is called Hawking Radiation because it was first hypothesized by Cambridge physicist Stephen Hawking. Matter from within the black hole does not travel at the speed of light to escape. The vacuum of space surround the black hole consists of a quantum froth of virtual particles of matter and antimatter coming in an out of existence. There is no violation of the law of conservation of mass and energy so long as the particles come in and out of existence in a period of time consistent with the Heisenberg Uncertainty Principle. If one of the virtual particles created near the black hole falls beneath the event horizon before annihilating with its partner then the black hole must lose the equivalent amount of mass of the particle trapped outside the event horizon. In this way the black hole appears to radiate particles. The process is very slow and it would take a google years (10100 years) for a supermassive black hole to completely evaporate.
A number of research groups have done computer simulations of the results of a black hole collision. Here a few links:
I hope that helps,
Dr. Bryan Méndez, UC Berkeley
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