At some point, most science fiction readers come across the “Big Three” authors from its so-called Golden Age: Robert A. Heinlein, Isaac Asimov, and Arthur C. Clarke. Over the course of his lifetime, Clarke witnessed the birth of the space age, and helped push science fiction from a nascent literary movement into a modern vision for humanity’s future with grounded, realistic stories that drew on science and technology—themes that are more relevant than ever today, on the 100th anniversary of his birth.

When Clarke began writing science fiction in the late 1930s, the genre was on the cusp of a major transformation. Up to that point, science fiction stories appeared in cheap pulp magazines, and were often sensational tales featuring murderous robots, outlandish planets, and swashbuckling adventure. As Clarke entered the field, the trend of scientific realism was on the rise, pushed along by editors like John W. Campbell, who ran the magazine Astounding Science Fiction. Clarke, whose writing was grounded in a firm sense reality, found himself at home in this burgeoning movement. His vision for the future set the mold for his many literary heirs, including Alastair Reynolds, James S.A. Corey, and Allen M. Steele.

Born in Minehead, Somerset on December 16th, 1917, Clarke discovered science fiction at a young age, which began his lifelong obsession with space and humanity’s place in it. He built his own telescopes, served as a radar officer during World War II, and in the late 1930s, began writing stories of his own. Clarke funneled his interests in physics and mathematics into his fiction, creating characters who embarked on missions that readers could easily imagine taking place just years away.

His longer works, such as 2001: A Space Odyssey, Rendezvous with Rama, Fountains of Paradise, and Childhood’s End, begin with simple, straightforward events—like the discovery of an alien monolith, the arrival of an extrasolar object, or the arrival of an alien spacecraft—and lead characters on remarkable, transformative journeys.

Clarke infused those journeys with plausible technology and recognizable settings, but also explored profound, transcendental notions about our place in the universe. He coined the frequently-quoted saying “Any sufficiently advanced technology is indistinguishable from magic.” His work often suggested that humanity is just one minuscule part of the cosmos—that there’s so much we still don’t know that could change the way we perceive the world forever.

In his 1951 short story The Sentinel, the discovery of an alien artifact on the moon leads to the realization that humans aren’t alone in the universe. In his 1953 story The Nine Billion Names of God, a group of monks use a supercomputer to fulfill their mission to list all of God’s names, believing that something incredible will happen when they do. Its conclusion leads to one of the genre’s most awe-inspiring closing lines: “Overhead, without any fuss, the stars were going out.”

While Clarke was often profound, he could also be witty. In 1958’s Who’s There?, he sets up a thrilling, claustrophobic tale where an astronaut is sent into space to retrieve a wayward satellite, only to feel something moving around in his suit. After accidentally knocking himself unconscious, he awakens back onboard the space station to discover that the station’s resident cat had been using his space suit as a home for her kittens.

A century after his birth, our understanding of the universe around us has continually and drastically changed; we’ve discovered vast numbers of planets and solar systems throughout the cosmos, as well as new discoveries and surprises closer to home. Through his hundreds of short stories and novels, Clarke paved the way for his successors to process the vast size and utter strangeness of this new terrain and explore one of science fiction’s most defining questions: what is humanity’s place in the universe?