Wednesday 26 January 2011

Black Hole:

A black hole is an astronomy theoretical celestial object, formed when a massive star collapses from its own gravity. A black hole has such a strong pull of gravity that not even light can escape from it.
Some scientists theorize that rotating black holes (also know as Kerr black holes) which contain billions of dead stars lie at the centers of galaxies.

The idea of black holes was first theorized in the late eighteenth century by English geologist John Mitchell and French astronomer Pierre Simon Laplace. At one time, scientists called them "gravitationally collapsed objects." Russian scientists suggested calling them "collapsars," but it wasn't until 1969 when Princeton physicist, John Wheeler coined the term black hole. Black holes have continued to hold public interest and are a popular fixture of science fiction books and movies.
Definition: black-hole dynamic laws:

Laws of black-hole dynamics -
First law of black hole dynamics: For interactions between black holes and normal matter, the conservation laws of mass-energy, electric charge, linear momentum, and angular momentum, hold. This is analogous to the first law of thermodynamics.
Second law of black hole dynamics: With black-hole interactions, or interactions between black holes and normal matter, the sum of the surface areas of all black holes involved can never decrease. This is analogous to the second law of thermodynamics, with the surface areas of the black holes being a measure of the entropy of the system.