This is the definitive collection of the twentieth-century's most characteristic genre--science fiction. The tales are organized chronologically to give readers a sense of how the genre's range, vitality, and literary quality have evolved over time. Each tale offers a unique vision, an altered reality, a universe all its own. Readers can sample H.G. Well's 1903 story ''The Land Ironclads'' (which predicted the stalemate of trench warfare and the invention of the tank), Jack Williamson's ''The Metal Man,'' a rarely anthologized gem written in 1928, Clifford D. Simak's 1940s classic, ''Desertion,'' set on ''the howling maelstrom that was Jupiter,'' Frederik Pohl's 1955 ''The Tunnel Under the World'' (with its gripping first line, ''On the morning of June 15th, Guy Burckhardt woke up screaming out of a dream''), right up to the current crop of writers, such as cyberpunks Bruce Sterling and William Gibson, whose 1982 story ''Burning Chrome'' foreshadows the idea of virtual reality, and David Brin's ''Piecework,'' written in 1990. In addition, Shippey provides an informative Introduction, examining the history of the genre, its major themes, and its literary techniques. These 30 SF tales, arranged chronologically from 1903 to 1990, cover a typically wide and uneven range in the genre. The omission of some authors might raise eyebrows--notably Isaac Asimov, Harlan Ellison, and Robert A. Heinlein, all known for their short fiction. Only three women are represented: C. L. Moore (whose The Piper's Son is written under the collaborative pseudonym Lewis Padgett), Ursula K. Le Guin and Racoona Sheldon (Alice Sheldon, better known under the James Tiptree Jr. pseudonym). Only Sheldon's The Screwfly Solution, a devastatingly scary story about misogyny gone mad, dates from the past 20 years, during which women have made serious progress in the genre; thus, the final third of the book is less representative than it might be. Standouts include Le Guin's 0. Henry-esque The Dowry of the Angyar, Gene Wolfe's frightening How the Whip Came Back, H. G. Wells's anticipation of modern weapons in The L