Thread: Black Holes
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Old 20-01-2010, 11:49 PM
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Quote:
Originally Posted by shane.mcneil View Post
Hmm all very interesting. It just seems to me that for a black hole to maintain a gravitational influence then the matter/energy that makes it up must still exist somehow. Otherwise there would no longer be a black hole?
Correct.

If there is one property about BHs that is well understood is it's mass. (Along with electric charge and angular momentum for spinning black holes).
The mass of a BH is calculated through Keplar's laws through objects in orbit around it.
The mass of BH varies from 1.4-3 solar masses for stellar type BHs up to 18 billion solar masses for BHs that reside at the centre of galaxies.

Due to the conservation of mass and energy, when matter falls into a BH it isn't destroyed. We may not know what form the matter takes except it becomes part of the BH mass.

Rather than being theoretical curiosities, the indirect experimental evidence for BHs is quite strong, particularly for supermassive BHs.

Regards

Steven
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