Asri-unix.980 net.space utcsrgv!utzoo!decvax!ucbvax!sri-unix!DIETZ@USC-ECL@Berkeley@CCA-UNIX Thu Mar 11 13:03:55 1982 Comet Showers From: Paul Dietz On the subject of close encounters with nearby stars (not aliens!), I read that a brush with a star could cause a "comet shower", sending thousands of comets from the cometary halo into the solar system. Many would collide with the planets, either immediately or after being deflected into closed orbits by the gas giants. Perhaps this happened 65 million years ago? De Sitter space: The argument that the de Sitter space thepry is false because the space must exist for an infinite period of time in a metastable state is flawed. For one thing, the space can produce unlimited numbers of separate universes. For another, how do you measure time? The best you could say is that there are infinitely long world lines. Spacetime cannot be said to exist at certain moments and not at others: the concept of time is meaningless unless spacetime exists. ------- ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.