"When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong." -- Arthur C. Clarke, author, 1962
Asimov, I., The Truth Isn't Stranger Than Science Fiction -- Just Slower, The New York Times, Feb 1984
Two astronauts floated free in space last week before their shuttle touched down in Florida yesterday. They were not tethered. They left the spacecraft and returned to it on their own.
Those of a certain age were reminded of Buck Rogers comic strips of the 1930's and 40's. All of it - the space walk, the rocket ship, the backpack - happened there. Those still better acquainted with science fiction (or s.f. and not the barbarous ''sci-fi'') know of stories that dealt with such strange phenomena even earlier. Hugo Gernsback, editor of the first s.f. magazine, was writing about reaction motors that kept men in flight, in Earth's atmosphere as well as in space, in 1911. It took reality only three-fourths of a century to catch up.
The trip to the Moon, accomplished in 1969, followed by more than a century the first attempt to describe such a voyage with some attention to scientific detail. That was Jules Verne's ''From the Earth to the Moon'' published in 1866. Verne's launch mechanism was a giant cannon. The idea was impractical and, in a sense, outdated, for rocketry in connection with a Moon flight had already been mentioned by Cyrano de Bergerac. Yes, the fellow with the nose was also a science fiction writer. His story was published in 1655, 30 years before Isaac Newton demonstrated that, at least in principle, a rocket could carry people to the Moon, and that as far as was known, then or now, only a rocket would do the trick. Rocketry, then, lags three centuries behind science fiction. And what now? Will further advances in space overtake and outstrip science fiction once and for all? No danger! The National Aeronautics and Space Administration is talking of a permanent space station occupied by a dozen astronauts at a time. But Gerard O'Neill suggested space settlements, virtual cities of 10,000 or more, back in 1974, following serious suggestions - advanced by scientists in the early 1960's - for building solar power stations in space. And even those were not original notions. Back in 1941, Isaac Asimov (that's the fellow writing this piece) published ''Reason,'' a story that described in some detail a solar power station in space. In 1929, Edmond Hamilton wrote ''Cities in the Air'' in which cities declare their independence of Earth's surface and loft themselves into the atmosphere. It was not quite space, but it paved the way for James Blish, who began his stories about cities of the cosmos in 1948. By the time stations and power plants are built in space, they will have lagged behind science fiction for at least half a century. Once we have space stations, we will be able to take longer space trips. Using materials mined on the Moon, sometimes mentioned in space travel stories of the 1930's, and the special physical conditions of space, ships much larger than those practical on Earth's surface could be manufactured and launched. They could be manned by people accustomed to space travel who would be psychologically fit, as Earth-bound folk are not, to spend months or even years in transit. Of course, it is all old hat in science fiction, where interstellar travelers have wandered the solar system since the 1920's.
After the solar system come the stars. The nearest stars would take years and decades to reach - even if we went at the speed of light, which in theory is the fastest possible. If we went at reasonable less-than-light speeds, it would take generations. There are various strategies for dealing with this space-time problem - every one of them pretested in science fiction. Arthur Clarke's story ''2001: A Space Odyssey'' placed astronauts into frozen hibernation to wait out the long journey. Poul Anderson's book, ''Tau Zero,'' was one of many that had astronauts take advantage of the relativistic slowing of time at high speeds. Back in 1941, Robert Heinlein described in ''Universe'' a large ship - actually a small world - whose passengers were ready to spend millenia, and countless generations, to reach their starry destination.
Will faster-than-light travel be possible? My inclination is to say ''No,'' though I know it is unwise to be too categorical in such things. Back in 1928, Edward E. Smith wrote ''The Skylark of Space,'' the first story of interstellar travel using faster-than-light speeds. He invented the inertialess drive, which is probably impossible and which, in any case, would only achieve light- speed, nothing more. Still, the principle remains.
What kind of mind is required to think of things to come a generation and more ahead? Nothing unusual, judging by my own. It's just a matter of knowing science and technology and the way they have developed, and of thinking what the next steps might logically be - and thinking and thinking. People expect dramatic shortcuts, but it all boils down to the dull, hard work of thought. Which doesn't mean that science fiction writers have anticipated everything. Their record isn't that good. For instance, they concentrated on space flight under direct human control and never realized what could be done by remote-controlled probes. They foresaw computers but missed their true role in space flight. No one, for example, predicted the advent of the microchip, the computer's compactness and versatility, and how essential it would become to piloting, say, a shuttle. Science fiction writers missed all sorts of activities that could be performed in space. We had trips to the Moon, but no weather satellites, no communication satellites (though Arthur Clarke first described them in a nonfiction piece in 1945), no navigation satellites. Oddly enough, although we foresaw both television and landings on the Moon, no one anticipated reality by describing a landing on the Moon that was watched by hundreds of millions of people on Earth as it happened. Only the comic strip ''Alley Oop'' came close. The conclusion is this. It is unlikely that science and technology, in their great sweeps, will outstrip science fiction. In many small and unexpected ways, however, there were and undoubtedly will continue to be surprises that no science fiction writer - or scientist, for that matter - has thought of. It is these surprises that are the excitement and glory of the human intellectual adventure.