Librivox: Short Science Fiction Collection 005 by Various

Summary: Science fiction (abbreviated SF or sci-fi with varying punctuation and case) is a broad genre of fiction that often involves sociological and technical speculations based on current or future science or technology. This is a reader-selected collection of short stories, originally published between 1960 and 1963, that entered the US public domain when their copyright was not renewed. Summary by Cori Samuel, with Wikipedia input.