What is "hard science fiction"

n. A subgenre of (l/en: science fiction) that focuses on technical detail and scientific accuracy.

Hard science fiction is a category of science fiction characterized by an emphasis on scientific accuracy or technical detail or both. The term was first used in print in 1957 by P. Schuyler Miller in a review of John W. Campbell, Jr.'s Islands of Space in Astounding Science Fiction. The complementary term soft science fiction, formed by analogy to hard science fiction, first appeared in the late 1970s. The term is formed by analogy to the popular distinction between the "hard" ( natural) and "soft" ( social) sciences. Science fiction critic Gary Westfahl argues that neither term is part of a rigorous taxonomy; instead they are approximate ways of characterizing stories that reviewers and commentators have found useful.

Stories revolving around scientific and technical consistency were written as early as the 1870s with the publication of Jules Verne's Twenty Thousand Leagues Under the Sea in 1870 and Around the World in 80 Days in 1873, among other stories. The attention to detail in Verne's work became an inspiration for many future scientists and explorers, although Verne himself denied writing as a scientist or seriously predicting machines and technology of the future.

Today, the term "soft science fiction" is also often used to refer to science fiction stories which lack any scientific focus or rigorous adherence to known science. The categorization "hard science fiction" represents a position on a broad continuum—ranging from "softer" to "harder".