The term "science fiction" was invented to describe a certain genre of literature popularized in the 1920s, when pulp fiction magazines specializing in this type of fiction first appeared. But as a genre of popular literature, under no particular name, science fiction is found in general fiction magazines throughout the 19th Century. Many of the themes invented by writers 100 to 150 years ago have penetrated the public consciousness so thoroughly that pseudoscience writers need only mention one or two key words to suggest a whole scenario in the mind of the reader! What is really frightening, however, is that the average reader probably thinks these familiar concepts borrowed from nearly two centuries of fantasy fiction are actual, well-established scientific fact real phenomena of the real world! In fact, the vast majority of these science fiction themes are fictional cliches without any fixed meaning, much less any correspondence to anything in the real world.
Let's discuss some of the more common themes that appear in 19th century fantastic fiction. These include:
The usual story goes that an explorer stumbles onto a "lost" civilization in some isolated part of the world; a high urban civilization that has no contact or communication whatsoever with the rest of the world, is geographically isolated by jungles or mountains, and, often, possesses a high technology. In the 19th Century this fictional cliché, particularly exploited by British novelist H. Rider Haggard, was a pleasant enough conceit, but it makes little sense today, with the globe so thoroughly explored. Furthermore, the concept of an advanced but totally isolated civilization has been widespread trade and frequent cross-cultural contacts. In 19th century fiction, the hero generally falls in love with the local princess and gets her out of the country just as a volcano or something similar destroys the civilization forever.
NEW ANIMALS, BOTH FOUND AND MADE
This was an especially popular theme in the latter part of the 19th century. Still-surviving dinosaurs could be found on a remote plateau in South America, as in The Lost World, by Sir Arthur Conan Doyle; familiar small animals could be made unrecognizably gigantic, as in The Food of the Gods, by H. G. Wells; or animals could be surgically turned into human beings, as in The Island of Dr. Moreau, also by Wells. Hence our inheritance of two familiar themes: those supposedly extinct animals are hiding out somewhere, and those meddling scientists can create monsters to menace us. Public fears of and legal interference with modern genetic engineering experiments probably stem mainly from such fantasies, not from any real threat or menace.
MECHANICAL LIFE -- ROBOTS AND ANDROIDS
Many writers explored this theme during the latter half of the 19th century, often as a social satire on the ultimate influence of assembly lines -- assembling peoples rather than products. In 20th Century science fiction the terms "robot" and "android" have clearly established meanings of which movie script writers and many others seem to be totally ignorant. A robot is any machine, which can do all or some of the work of a man without human supervision. An android is an artificial human; it can operate mechanically or biochemically, but it is manufactured. The concept of mechanical life grew up out of the fad for clockwork automatons that continued from themid-18th to mid-19th century. Typical is the Ambrose Bierce story, Moxon's Master, in which a mechanical chess player ultimately murders its designer.
VISITORS FROM OTHER PLANETS
This is probably the single most familiar theme from science fiction. As soon as people suspected that life is a natural phenomenon, which may appear anywhere conditions are right, and that the other planets are worlds like earth, the possibility that intelligent creatures from other planets might visit us became a common topic of discussion. Sometimes the visitors of fiction were peaceful and came to Earth seeking knowledge; other times they were desperate and/or warlike, and came to earth seeking conquest. Reality is quite different. There is no evidence whatsoever that creatures from any other world have ever visited Earth, and our increasing knowledge of the other planets of our solar system -- none of which is suitable for life -- makes clear why we haven't been visited. Visits from other solar systems are an extremely remote possibility, in view of the vast distances between stars with solar systems and the vast numbers of such systems to choose from.
VISITS TO OTHER PLANETS
This tradition in literature goes back nearly 2,000 years, but only in the 19th century did writers of such stories generally try to describe the other planets as they actually were thought to be, rather than as imaginary Cloud-coocoolands in which anything was possible. Nineteenth century fiction about visits from and to other planets had a strong influence on the 19th century pseudoscientific religion of Theosophy, and through it on much of 20th century pseudoscience. (Did you know, for instance, that the Earth was once colonized from Venus?!? Or that Atlantis had a death ray?!?)
TIME TRAVEL INTO THE PAST
There is no debate, even among science fiction writers, that this is completely impossible. It not only involves violations of the laws of physics, particularly the Second Law of Thermodynamics, but literally and actually involves gross logical contradictions. The idea is that mad Dr. Soandso gets into his time machine (not clearly described) and somehow goes back to ancient Rome, where he gives a translated handbook of physics and chemistry to a Roman scholar, and thus utterly changes the course of human history the atomic bomb, for instance, is then invented by Claudius Festus Arpinna in 350 AD. Despite the fact that even the writers agree time trips into the past are an impossibility, they love to play with them, because of the plot complications that can be generated by the logical contradictions that arise. My favorite books of this type are Dinosaur Beach by Keith Laumer and The End of Eternity by Isaac Asimov. The time-travel short story to end all time-travel short stories is All You Zombies! By Robert A. Heinlein. Wells' 19th Century The Time Machine is the genre's daddy.
SUSPENDED ANIMATION OR TIME TRAVEL INTO THE FUTURE
Nothing impossible about this, and a pseudoscientific rewrite of the Rip Van Winkle plot was the easiest way for a writer to get his 19th century Every man into the Utopian future to comment, marvel, and react. A classic example is Wells' When the Sleeper Wakes. However, travel into the future (possible -- in fact, unavoidable!) is not much fun unless you can return to the past to tell the home folks what you saw (impossible).