Message-ID: <348449F2.E8B220DD@usa.net> Date: Tue, 02 Dec 1997 10:48:35 -0700 From: The Privateer Reply-To: privateer@thevortex.com To: Tenchi Muyo ML Subject: Re: Black Holes Here are the definitions of black holes from NASA (if you are not interested stop reading now): Micro-Black Holes Formation Possibly formed in small regions of high density during the first few seconds of the Big Bang. Unusual Features Micro-black holes aren't so black! Quantum mechanics and thermodynamics tell us that they should radiate all forms of energy due to the strongly varying gravitational fields just outside their event horizon. These black holes slowly radiate themselves away, finally disappearing in a flash of high-energy radiation. Size If a micro-black hole is created with a mass of greater than 10^17 grams, it would still be around today. This mass corresponds to about a cubic kilometer of water. In terms of size, it would be smaller than an electron! Observations Once believed to be a possible source of gamma-ray bursts, there is no current observational evidence for their existence. Stellar-Mass Black Holes Formation When a star with a mass of greater than 10 times the mass of the Sun explodes in a supernova, the central core left behind will collapse into a black hole. Unusual Features When this type of black hole is part of a binary system, matter can sometimes stream from the other star into a disk surrounding the black hole. This is called an accretion disk. Size These black holes would range from about 5 to 100 times the mass of the Sun, giving them diameters of 20 to 400 miles. Observations At present, there are over 25 objects astronomers suspect may be black holes near or in our own galaxy. A partial list: Cygnus X-1, A0620-00, V404 Cygni, LMC X-1, LMC X-3 Super-Massive Black Holes Formation Formed via accretion from smaller bodies in the centers of many galaxies. Unusual Features On this scale, some of the infalling matter may become redirected into jets and ejected over the poles of the black holes. This phenomenon may explain the radio jets observed from the centers of some galaxies. Size HUGE! One million to one billion times the mass of the Sun. They would be about the size of our solar system. Observations Active Galactic Nuclei (AGN), Seyfert Galaxies, Quasars. If this is not enough information for you, you can go to the site: http://www.geocities.com/Area51/Cavern/6910/high-crusade.html and page down to the NASA search engine, and enter the words "black holes" (without quotes). You will even find articles about the Hubble telescope's evidence of the existance of black holes. -- Your humble servant (but hide the good china), The Privateer Anime Files at http://www.geocities.com/Area51/Cavern/6910/anime.html Free Web Cruiser at http://www.geocities.com/SiliconValley/Vista/7829/cruise.html