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Old 08-10-2009, 03:13 PM
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Robh (Rob)
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Join Date: Feb 2009
Location: Blue Mountains, Australia
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Quote:
Originally Posted by Paddy View Post
Mind boggling indeed, even more so since they are 1 million - 1 billion times the mass of the sun, but have no size at all. A black hole is a mathematical point as far as I understand.
In General Relativity, a black hole can be thought of as a massive singularity.
However, the physical size of the black hole is measured as the radius of the event horizon, the point of no return for matter and electromagnetic energy. Also known as the Schwarzschild radius. If the Sun were a black hole, its radius would be about 3 km.

Regards, Rob.
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