Black Holes :: essays research papers

The theory that black holes have existed is not new at all. The thought of them first started in 1783 when Rev. John Michell applied Newton’s theory of gravity to predict the possibility of so-called â€Å"dark stars.† Albert Einstein’s theory of relativity predicted in 1915 â€Å"Schwartzschild singularities.† In 1967, these were renamed â€Å"black holes.†   Ã‚  Ã‚  Ã‚  Ã‚  A black hole is collapsed object (usually a star) that has become invisible and has such a powerful gravitational force that nothing, even light, can escape its surface. This is the reason that they are invisible. They are so powerful that one could easily crush an enormous amount of matter into an incredibly small space. For instance, if the earth were to be squeezed into a black hole, it would end up as the size of a marble.   Ã‚  Ã‚  Ã‚  Ã‚  A black hole forms when a super massive star has â€Å"used up† all of its nuclear fuel and then collapses under its own gravitational force. This happens because, as a star burns fuel, it creates an outward push, which counteracts the inward pull of gravity. Once the fuel is gone, the internal pressure of the star drops and it can no longer support its own weight. In a monstrous explosion, the outer layers are thrown off. And, at this same moment, the core collapses. This can happen rather quickly because gravity can crush an object 10,000 miles across to an object only 10 miles across in about one second.   Ã‚  Ã‚  Ã‚  Ã‚  During the time that a black hole is created, the star shrinks down to an infinitely small and infinitely dense point know as the singularity. At this point, all we have ever known about the universe breaks down. Around the singularity there is an imaginary circle called the event horizon. This is the black hole’s gravitational boundary where not even light can escape. Once this boundary has been crossed, there is no return. You could never actually see an object fall into a black hole. As it approaches the event horizon, time would slow down to the point in which it would take an infinite amount of time to reach it. Meanwhile, the black hole’s gravitational pull on light would give the effect that the object is fading away. If that object were a person, these are the effects that he would feel: As he fell into the black hole, he would instantly be stretched out because