Black Holes Essay -- essays research papers fc

Black holes are one of the many things in the universe that scientists still have a muddy understanding about. However, with the incredible advances of technology, we are able to understand more than what we have in the past. Today, the only way to observe these incredible objects are by looking for radiation from the gas surrounding it. What are they? Black holes are no more than a  ³dead star. ² A star that is considered  ³alive ² would be our sun. The sun still produces energy by converting hydrogen into helium, thus considered to be  ³alive. ² Once a star has run out of hydrogen, it begins its dying process. The final stage may result in a black dwarf, which is a small cool object no longer radiating energy, or if the star harbors enough mass it could result in a black hole. Black holes are defined as a collapsed star. The difference between a black dwarf and a black hole is the original mass of the star, which determines whether or not that star will have enough gra vitation force to collapse upon its self and form a suction, or to remain as that small cool object, a black dwarf. Why do black holes suck everything in? To understand why material that enters a black hole is unable to escape, one must understand the concept of escape velocity. This is the velocity (speed) at which any material needs to exceed in order to escape from something. Because, as Einstein said,  ³What ever goes up must come down! ² In other words, in order for a space craft to exit the Earth ¹s atmosphere so that it must not come down, it must exceed a certain speed. In order to figure out the Earth ¹s escape velocity one takes the square root of the planet ¹s mass divided by the planet's radius. PLANET ¹S MASS / PLANET ¹S RADIUS = ESCAPE VELOCITY On Earth with a radius of 6,500 km, the escape velocity would be 11 km/sec. Therefore to launch any object away from Earth, the object must travel (escape) faster than 11 km/sec. All of this is of course the result of gravity. However, imagine a huge vise that squeezed the Earth to one-quarter its present size. What would then happen to the escape velocity? The velocity would increase because the mass would increase as the radius increased. Thus, taking the square root of a larger number, ending up with a larger number that being the escape velocity. The actual escape velocity of this hypothetical question would double it making it 22 km/sec. Taking ... ... horizon, which would emit radiation because of this. The thermal radiation is so hot that it is expected to be x-ray types of radiation. Once the radiation surpasses the even horizon, the x-rays cease and the material inside continues in great distortion. This is what scientists are trying to link to their observation of such radio active areas within out universe today. Bibliography Abell, George O. Exploration of The Universe. Holt, Rinehart and Winston, 1975. Berger, Melvin. Quasars, Pulsars and Black Holes In Space. Canada: Longman Canada Limited, 1977. Bisnovatyi-Kogan, G.S.  ³At The Border of Eternity. ² Science. February, 27, 1998: 1321- 1322. Chaisson, Eric. Relatively Speaking. Canada: The Readers Digest Association Ltd., 1990.  ³Down The Galactic Drain. ² Discover. April 1998: 25. Shipman, Harry L. Black Holes, Quasars, and The Universe. Boston: Houghton Mifflin Company, 1976. Sullivan, Walter. Black Holes- The Edge of Space, The End of Time. New York: Anchor Press, 1979. Taylor, John G. Black Holes: the End of The Universe?. New York: Random House Inc., 1973.  ³The Astronomers- Searching for Black Holes. ² Community television of Southern California, 1991.