Pebble in the Sky is a science fiction novel by American writer Isaac Asimov, published in 1950. This work is his first novel — parts of the Foundation series had appeared from 1942 onwards in magazines, but Foundation was not published in book form until 1951. The original Foundation books are also a string of linked episodes, whereas this is a complete story involving a single group of characters.

Startling Stories was an American pulp science fiction magazine, published from 1939 to 1955 by publisher Ned Pines' Standard Magazines. It was initially edited by Mort Weisinger, who was also the editor of Thrilling Wonder Stories, Standard's other science fiction title. Startling ran a lead novel in every issue; the first was The Black Flame by Stanley G. Weinbaum. When Standard Magazines acquired Thrilling Wonder in 1936, it also gained the rights to stories published in that magazine's predecessor, Wonder Stories, and selections from this early material were reprinted in Startling as "Hall of Fame" stories. Under Weisinger the magazine focused on younger readers and, when Weisinger was replaced by Oscar J. Friend in 1941, the magazine became even more juvenile in focus, with clichéd cover art and letters answered by a "Sergeant Saturn". Friend was replaced by Sam Merwin Jr. in 1945, and Merwin was able to improve the quality of the fiction substantially, publishing Arthur C. Clarke's Against the Fall of Night, and several other well-received stories.