Perpetual Motion (Short Story) (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. "Perpetual Motion" is a science fiction short story written by L. Sprague de Camp, a story in his Viagens Interplanetarias series. It was first published under the title "Wide-Open Planet" in the magazine Future in the issue for September-October, 1950. It first appeared in book form under the present title in the collection The Continent Makers and Other Tales of the Viagens, published in hardcover by Twayne Publishers in 1953, and in paperback by Signet Books in 1971. It was also included in the paperback edition of The Queen of Zamba published by Dale Books in 1977. This edition was reprinted by Ace Books in 1982 as part of the standard edition of the Krishna novels. The story has been translated into Portuguese, Dutch, and Italian.