All the stories in this collection were published previously, and all fit into the “young adult” category of Heinlein’s body of work because none deals explicitly with sexual content. Although Heinlein did not necessarily intend to be prophetic with his series of connected stories, his engineering background and strong interest in subjects such as sociology and human psychology, along with his insistence on believable science, resulted in many of his science-fiction extrapolations becoming scientific fact. Heinlein provides the outline of the future, even if the details do not correspond exactly: The world still awaits the mechanical housekeepers of The Door into Summer (1957), and the computers described in his early science fiction are not nearly as sophisticated as personal computers of the 1990’s. The effect of a national transportation strike in “The Roads Must Roll” is one example of prophecy. The dilemma of nuclear power safety as exemplified by the disaster in Chernobyl in April, 1986, was explored in both “Blowups Happen” and “The Long Watch” (1948).
James Blish describes Heinlein as the best all-around science-fiction writer of the modern (post-1926) era in his introduction to Alexei Panshin’s Heinlein in Dimension (1968). Heinlein was such an influential writer in part because at some point in his writing career he explored virtually every possible science-fictional theme. Clever plot twists, based on science as it was known when the stories were written, provide recurring satisfaction for Heinlein’s readers. As an introduction to and an example of the early magazine works in the field, this collection is an excellent choice.
Although the future history chart (Astounding Science-Fiction, 1941) that these stories were collected to coincide with appears in other Heinlein works, it is not printed in the Ace paperback (1987) edition of The Past Through Tomorrow (1967), despite Damon Knight’s introductory statement to the contrary. As a common background for Heinlein’s stories, the future history chart provides a consistency to his storytelling without making the stories in this work dependent on one another.
Many of the themes first appearing in these short stories recur in later Heinlein novels. “Requiem” (1939) describes commercial lunar exploration, an idea further developed in “The Man Who Sold the Moon.” Aspects of both of these short stories appear both in Rocket Ship Galileo (1947), a novel made into the film Destination Moon (1950), and in The Moon Is a Harsh Mistress (1966), Heinlein’s 1967 Hugo Award-winning novel.