Mary Shelley’s Frankenstein ( 1818) is widely regarded as the first proper science fiction novel. Ever wondered how to define sci- fi and fantasy? Here’s a handy summary from The Twilight Zone creator Rod Serling: “Fantasy is the impossible made probable. Science fiction is the improbable made possible.” The first person to coin the term “sci- fi” was the late Forest J Ackerman in 1953. Of the top 50 highest grossing movies of all time, only five wouldn’t qualify as “SFX territory”.