Reading Arthur Clarke is exhilarating, to say the least. All that exuberant imagination, ebullient optimism, joie de vivre is strong medicine against current doomsdayers or Spengierians. This collection--mostly past lectures, television commentaries, or magazine pieces with fore- and afterwords--spans several decades. It ends on the eve of Clarke's 60th birthday, on which date he is to deliver a yet-to-be-written novel, "The Fountains of Paradise." Throughout, personal memoirs mingle with prognostications, sci-fi with sci-fact. One learns that heaven for Clarke is living in Ceylon, now Sri Lanka, in ancient times Serendip; that he took up deep sea diving in his thirties, finds the sea almost as compelling as space, and was party to the discovery of sunken treasure off Ceylon's south coast. There are anecdotes about Willy Ley or Vannevar Bush, accolades to Edgar Rice Burroughs or H. G. Wells, and good-natured kidding about friends Asimov and Stanley Kubrick, neither of whom will set foot in a plane. (That fact may preclude production of any Sons of 2001.) There are times when optimism and the technological fix venture beyond hyperbole--as per the use of oil to produce meat "indistinguishable from the natural product in taste, appearance, and nutritive value. . . " or the statement that "all pollution is simply an unused resource." But Clarke's definition of human beings as information-processing animals may not be hyperbole. Indeed much of the hope he sees for mankind is in the constructive use of space technologies to link individuals on earth and ultimately make cosmic connections. His discussions of the techniques available and the several essays in which he takes up the interrelation of knowledge with technology or speculates about life in 2001 make for some of the most stimulating parts of this personal/scientific potpourri.