Since the publication of Einstein's ''Special Theory of Relativity'' in 1905, the discovery of such astronomical phenomena as quasars, pulsars, and black holes -- all intimately connected to relativity -- has provoked a tremendous upsurge of interest in the subject.This volume, a revised version of Martin Gardner's earlier ''Relativity for the Million, ''brings this fascinating topic up to date. Witty, perceptive, and easily accessible to the general reader, it is one of the clearest and most entertaining introductions to relativity ever written. Mr. Gardner offers lucid explanations of not only the special and general theories of relativity, but of the Michelson-Morley experiment, gravity and spacetime, Mach's principle, the twin paradox, models of the universe, and other topics. A new Postscript, examining the latest developments in the field, and specially written for this edition, is also included. The clarity of the text is especially enhanced by the brilliant graphics of Anthony Ravielli, making this ''by far the best layman's account of this difficult subject.'' -- ''Christian Science Monitor. ''