"The only way to discover the limits of the possible is to go beyond them into the impossible."

- Arthur C. Clarke (Clarke's Second Law from his essay Hazards of Prophecy: The Failure of Imagination)

Legendary science fiction author Sir Arthur C. Clarke died March 19 at his home in the island nation of Sri Lanka. He celebrated his 90th birthday in December 2007, but had suffered from post-polio syndrome in his later years. His death was the result of respiratory problems.

Arthur C. Clarke was best known in popular culture as one of the most notable and talented writers of the science fiction genre.  Holding degrees in both physics and mathematics, he often grounded his fantastical characters and plot-lines with a basis in science.  He had more than 100 books, several film adaptations, and numerous awards to his name, and his novels include 2001: A Space Odyssey, Childhood's End, and the Rama series.

It could be argued that his most significant contribution was not to literature but to science and technology. Building on the earlier theories of Herman Potocnik and Konstantin Tsiolkovsky, he envisioned the conceptual framework that led to the invention of geostationary satellites, enabling signals to be relayed to and from the ground and orbiting machines in space as a means of transmitting communications over a wide area of the earth's surface. His theoretical paper was published in 1945, and his dream was realized 19 years later. The synchronous orbit into which these geostationary satellites are placed is referred to as the Clarke Orbit.

Some of Clarke's other ideas include space elevators, cryogenics, detecting and preventing asteroid collisions, nuclear powered spacecraft, and earthquake detection.  Many of these continue to be researched by scientists, and a few have already been implemented in some form.

In addition to being a writer and inventor, Clarke was also an avid scuba diver. Exploring the underwater world in the same way that some of his fictional characters explored intergalactic worlds, he spent much of his free time beneath the ocean's surface. He founded his own school for scuba diving near his home in Sri Lanka.

Clarke had no children of his own, but has left us all with a great legacy. He helped to open the minds and spirits of many of those exposed to his work. In his final year, Clarke wished for mankind to break its dependence on fossil fuels, for peace to be established in Sri Lanka, and for the discovery of extraterrestrial beings. On his 90th birthday, Clarke bid farewell to fans, expressing his desire "to be remembered most as a writer — one who entertained readers and, hopefully, stretched their imagination as well."