Fans of science fiction have a somewhat well-deserved reputation for nit-picking. Debates of the subtle meaning and implications of some minor detail of a book or movie are legion. In fact, part of the reason why we find science fiction enjoyable is that it gives fodder for such intellectually stimulating debates.
One of the oldest such controversies asks the question, “exactly what is science fiction?” in the sense of defining the category — “what rule we can use to determine whether a given creative work counts as science fiction or not?”
The question is made more confusing by the fact that there are numerous other genres — fantasy, space opera, Gothic literature, paranormal romance, and so on — that share some similarities with science fiction. (All of these genres fall within the super-category of “fantastic literature” or “literature of the imagination”.)
Among the many definitions of science fiction, my two favorite are the Aldiss definition (stated by Brian Aldiss) and the Gerrold definition (by David Gerrold).
The Aldiss definition is uplifting: “Science fiction is the literature that explores the relationship between mankind and the universe.”
The Gerrold definition is more pragmatic: “A story is a person with a problem. A science fiction story is a person with a problem involving science.”
As a general rule, I tend to include creative works that fit either of these definitions into the category of science fiction.
Note that neither of these definitions mentions anything about spaceships, aliens, time travel, or any of the standard SF tropes. Just because a movie has space travel in it does not make it science fiction; conversely, a movie can be science fiction without having any futuristic gadgets or technology.
Take for example, Star Wars. Most fans would agree that Star Wars is properly considered space opera rather than science fiction. Space opera is a genre in which the characters have rollicking adventures in space with dueling spaceships, ray-guns, exotic aliens and so on. But there is not a speck of science anywhere to be found in the Star Wars movies. You could change the spaceships to sailing ships, change the aliens to exotic foreigners, and set the whole thing in the year 1632, and none of the essential details of the plot would need to be altered.
Conversely, there’s nothing futuristic or high-tech about the excellent movie Children of Men, in which the entire human race has lost the ability to bear children, except for one woman. But it is certainly science fiction in both senses — it explores how humanity would react if faced with certain biological extinction, and the problems that the protagonist faces definitely involves science!
There have even been science fiction stories that, on a superficial level at least, appear to be classic fantasy. One of the best known of these is Anne McCaffery’s Dragonriders of Pern, in which the characters are living in a quasi-medieval lifestyle and fly around on fire-breathing dragons — yet the inhabitants of this planet are desperately trying to advance their knowledge of the world, using both reasoning and experimentation to escape the primitive conditions they are trapped in. In other words — science!
You may have noticed that as simple as the Aldiss and Gerrold definitions are, they imply a deeper question that needs to be answered: “If science fiction is about science, then what exactly is science?”
For example, I stated above that there was no science to be found within the Star Wars movies, and yet such as statement is only meaningful if we have some way to decide what kinds of story elements are scientific and what are not.
Many classic science fiction stories are based around a “what if” proposition: “what if biological sex was not fixed at birth?” (Ursula K. LeGuin’s The Left Hand Of Darkness) or “what if we could manufacture people?” (Phillip K. Dick’s Do Androids Dream of Electric Sheep). Some great SF novels, such as Frank Herbert’s Dune, or Neal Stephenson’s Anathem, involve dozens of “what ifs” or more.
However, it is also possible to ask “what if” questions of a more prosaic nature, such as “what if a retired cop married a famous Broadway actress?”. This is certainly not science fiction. One thing that is different about this “what if” question is that it lacks universality — the outcome of the question only affects a limited number of characters, and for the rest of us, life goes on unchanged.
I’m not going to try and give a complete and consistent definition of science for the purposes of judging what is and is not science fiction; Such a definition would be complex and almost certainly controversial.
One reason why it would be difficult to create such a definition — and what I really want to discuss in this essay — is the fact that science is not static, and the answer to the question “what is science?” changes over time.
Long ago, when the Enlightenment was just getting started, it was observed that while science could explain many of the aspects of our world that were previously thought to be the Will of God (such as the orbits of the planets, or the complex anatomy of living beings), there were other things that remained mysteries, and could thus be used as “proof” of the existence of a divine intelligence.
Later, it was observed that as science got better, the number of such mysteries decreased over the years. The phrase “God of the gaps” was used to describe a theological perspective in which God’s handiwork could only be observed in those realms which science had not gotten around to explaining yet. As science marched onward, the “gaps” grew smaller, and the role for God diminished with each passing year.
I would like to propose a similar perspective for thinking about science fiction as a “literature of the gaps”. As science learns more about the universe, things that seemed fantastic become commonplace; and stories involving them, which once might have been science fiction, are no longer so.
Think of it this way: if we know that a story concept is completely impossible (like rubbing a lamp and summoning a wish-granting genie), then that story is clearly fantasy.
On the other hand, if the story is based around a concept that we know for sure exists (like long-distance communication to anyone on the planet using a portable device in your pocket) then that story isn’t science fiction or even fantastic literature — it’s just a mundane or “mainstream” story.
Somewhere between these two extremes — where a concept is not known to be true, but has a scientifically plausible explanation — is where science fiction lives.
I should note here that a creative work need only have a single scientific idea to be considered science fiction, regardless of how many other fantastic, non-scientific concepts are contained within, so long as that scientific idea is in some way important to the story. Thus, a story about a genie is science fiction if it explores what would be the economic consequences of having wishes granted.
When Dick Tracy used his portable wrist-radio to coordinate his police activities in the 1930s newspaper comics, you could reasonably argue that this should fall into the category of science fiction. Radios small enough to fit on your wrist did not exist then, but were well within the realm of believability. But if the same story were written today, it would not be considered fantastic at all.
Similarly, our increased understanding of the laws of physics and biology can close off certain possibilities, transforming stories from science fiction into fantasy.
If someone were to write a story like H. G. Wells’ The Time Machine today, it would probably be considered planetary romance rather than science fiction. Planetary romance is a genre in which characters are transported to an exotic, alien environment, have adventures, fall in love, and either live happily ever after or come to some tragic end.
Similarly, works such as E. E. Doc Smith’s The Lensman Series (written in the 1930s) contain pseudo-scientific explanations of how spaceflight is achieved, but such explanations are so out of line with modern scientific thinking that you would have to consider the books to be pure space opera.
I want to examine what is probably the most common scientific trope in science fiction literature, which is the notion of interstellar travel.
These days the existence of interstellar travel, by itself, does not make a work science fiction. However, if there is a scientifically plausible explanation of how interstellar travel works that is of interest to the reader, then that would qualify, making it “hard science fiction”. If the book examines the social consequences of interstellar travel, that would also qualify, making it “sociological science fiction”.
Most such stories involve the ability to travel faster than light, using some sort of warp drive, hyperdrive or other means. Almost all fictional FTL drives fall into about five or six categories — TVTropes has a good list if you are interested.
However, in the real world we have never observed any phenomena that travels faster than light, and there’s no scientific evidence or theory that would incline someone to believe that such travel is possible.
Instead, the rationale for most fictional FTL drives are based around the lack of evidence to the contrary. In other words, our scientific understanding does not promote the concept of FTL travel, but it does not absolutely rule it out either.
A textbook example of this is the concept of tachyons, hypothetical particles that can only travel faster than light.
You see, Einstein’s theory says that no object with mass can travel at exactly the speed of light, because its mass would become infinite. But what about particles traveling faster than the speed of light? The equations are mute on this point, so the idea of tachyons was born.
Unfortunately, no one has ever observed a tachyon; worse, no one has ever observed any phenomena that would provide even the most indirect evidence of a tachyon. There’s no good reason to believe they exist.
And as science advances, those gaps get smaller every decade.
Thus, the concept of FTL slowly moves from the realm of science fiction into the realm of fantasy.
FTL is still around in science fiction literature because it’s simply too useful of a story trope to let go of. People like reading stories about adventures on exotic planets and strange alien creatures. If it requires decades to travel between the stars, this creates a very different (and frankly, darker) story atmosphere.
Most of the stories written today that incorporate FTL are either plain and simple space opera, or have some other scientific story concept, in addition to FTL, that lets them hold on to the science fiction label.
The other major form of interstellar travel is, of course, sublight travel. However, even this has come under attack in recent years, as the “gaps” in our knowledge shrink — as we gain a better understanding of fragile ecosystems, human biology, and the factors that allow human cultures and political systems to be stable over long periods of time. Kim Stanley Robinson’s recent novel Aurora is in fact a deconstruction of the sublight travel trope, but it is not the only critique out there.
My personal belief is that the universe will be colonized by our robotic descendants, who can simply “power down” for a few decades when needed to conserve energy, and who don’t require complex ecosystems to survive. If we ourselves travel between stars, it will likely be in the form of data (a concept explored in many novels, and the recent Netflix series Altered Carbon).
Why is this important? Why does it matter if scientific ideas, and therefore the definition of science fiction, change over time?
It’s important because it challenges authors to come up with fresh ideas.
The idea of FTL travel as a story trope has been around for something like 80 years (it actually originated long before that, but it only became a staple of science fiction in the pulp era). A story whose only imaginative concept is travelling to other star systems is simply not enough to stimulate the imagination of the modern SF reader; the ideas would be considered stale and boring. FTL as a trope can only exist today in stories that mix it with newer, fresher ideas.
(Note that TV and movies tend to lag 20–30 years behind literary SF; it often requires several decades for ideas to migrate to the screen.)
What are some examples of newer science fiction tropes? One that is only about 25 years old can be seen in many novels like Charles Stross’s Accelerando, Doctorow’s Walkaway, David Brin’s Existence, and even some recent TV shows like Altered Carbon: the “self as computational product” concept. Basically it extrapolates the impact of computers on our lives, and posits a future in which our bodies or our minds are shaped or even generated by software algorithms.
But as a reader, I am constantly on the lookout for the Next Thing. What will it be?
Footnote: Every one of the books mentioned in this article is a classic, and is well worth reading.