Black Holes :: essays research papers

Black HolesA glum hole is the f number necessary to take one away from ones confess gravitational force. For example, the escape velocity of earth is equal to 11 km/s. any amour that wants to escape earths gravitational force or pull must go at least 11 km/s, no matter what the thing is . The escape velocity of an object depends on how compact it is that is, the ratio of its press to radius. A black hole is an object so compact that, fold up to it, even the speed of light is not fast enough to escape.A common type of black hole is the type produced by nigh dying flairs. A star with a mass greater than 20 times the mass of our Sun may produce a black hole at the end of its life. In the normal life of a star there is a constant tug of war amongst gravity pulling in and pressure pushing out. Nuclear reactions in the mall of the star produce enough energy to push out. For most(prenominal) of a stars life, gravity and pressure balance each other exactly, and so the star is sta ble. However, when a star runs out of nuclear fuel, gravity gets the amphetamine hand and the material in the core is compressed even further. The more than than grand the core of the star, the greater the force of gravity that compresses the material, collapsing it nether its aver weight. For small stars, when the nuclear fuel is exhausted and there are no more nuclear reactions to fight gravity, the repulsive forces among electrons within the star at last create enough pressure to halt further gravitational collapse. The star then cools and dies peacefully. This type of star is called the "white dwarf." When a very massive star exhausts its nuclear fuel it explodes as a supernova. The outer split of the star are sent into space and the core falls under its own weight. To create a massive core a primogenitor (ancestral) star would need to be at least 20 times more massive than our Sun. If the core is very massive (approximately 2.5 times more massive than the Sun), n o known repulsive force inside a star can push back hard enough to anticipate gravity from completely collapsing the core into a black hole. Then the core compacts into a mathematical point with zero volume, where it is has infinite density.