Asri-unix.1065 net.space utcsrgv!utzoo!decvax!ucbvax!ARPAVAX:C70:sri-unix!KATZ@USC-ISIF Sun Mar 21 02:24:51 1982 Re: SPACE Digest V2 #135 Thought experiment in general relativity: How do you define a straight line? It turns out that a "straight" line is the path of a light ray, so by definition, if you have a "straight" rod, a beam of light would follow it. However, "straight" here means a geodesic which is a straight line in a curved space. Alan ------- ----------------------------------------------------------------- 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.