Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site utastro.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!ut-sally!utastro!ethan From: ethan@utastro.UUCP (Ethan Vishniac) Newsgroups: net.books,net.sf-lovers,net.physics Subject: Re: Procyon's Promise & antimatter black holes Message-ID: <518@utastro.UUCP> Date: Fri, 9-Aug-85 15:07:44 EDT Article-I.D.: utastro.518 Posted: Fri Aug 9 15:07:44 1985 Date-Received: Mon, 12-Aug-85 05:56:13 EDT References: <320@baylor.UUCP> <1491@shark.UUCP> <313@ttrdc.UUCP> <560@mmintl.UUCP> <530@brl-tgr.ARPA> Distribution: net Organization: U. Texas, Astronomy, Austin, TX Lines: 30 Xref: linus net.books:2037 net.sf-lovers:8261 net.physics:2824 [] A few comments about Black Holes. First, when people make comments about all BH's being alike no matter what they are made of, they are referring to their effects on the rest of the universe. Since physics as we know it breaks down near the center of a BH people normally refrain from making comments about life inside a BH. Not only is the gravitational field of an BH made from anti-matter identical to one made from matter, but when BH's evaporate due to quantum mechanical processes, they emit equal amounts of matter and anti-matter *no matter what they were originally made of*. Second, when people talk about fitting the universe inside a BH they are not talking about conventional physics. The theory of GR says that in the center of a BH a singularity forms in one spot and continues for all future times (although what happens as the BH evaporates is not clear). Models of the universe (the successful ones) have a singularity at one time over all of space. Third, for quantum mechanical reasons no BH can be smaller than 10^-5 grams in weight. In fact, a BH weighing a metric ton would evaporate in about 10^-10 seconds (the lifetime is proportional to the mass cubed). Therefore it is probably nonsensical to talk about BH's the mass of a subatomic particle. -- "Support the revolution Ethan Vishniac in Latin America... {charm,ut-sally,ut-ngp,noao}!utastro!ethan Buy Cocaine" ethan@utastro.UTEXAS.ARPA Department of Astronomy University of Texas