Dr. James Van Allen
"Seriously, one of the things that is very, very difficult to portray when writing anything involving Space is the truly ridiculous distances involved in anything."
(for whom the Van Allen Radiation Belt
is named) was once asked by a reporter to 'define space'. He replied, "Space is the hole that we are in."
Most people (if not, in fact, everyone
) can't get their minds around just how big the universe is. So it should come as little surprise that most Speculative Fiction
writers can't either.
This is chiefly true of creators of TV, film, and video game SF. Creators of written
science fiction can be positively obsessive about accuracy (but on the other hand, sometimes they're not
). If your qualitative yardstick is based around an author's ability to describe distances, this may be a useful way to distinguish good print science fiction from bad print science fiction. And it's why a lot of science fiction fans don't like the movie and TV adaptations of their favorite books and stories. The usual blend of Adaptation Decay
and bad research is a surefire way to leave the adaptation with no sense of scale
On the other hand, "Space is so ridiculously huge that there is absolutely no realistic way that anyone could ever travel to anywhere even remotely interesting in the lifespan of most major civilizations", while not a total deal-breaker, does rule out an awfully broad range of plots.
For example, consider that a light year is about ten quadrillion
meters or nearly six trillion
miles. That's 10 petameters. Let's assume your family car uses about 2 and a half gallons (11.37 litres) of fuel per 100km - about 25 mpg - and a gallon (2.55 litres) costs about $4 USD (i.e. 1.6 USD/1 Euro per litre) to traverse it. This means that one light year is roughly where you'd end up if you spent the entire national debt of the US on petroleum fuel note
. At the opposite end, an atomic nucleus is on the order of a quadrillionth
of a meter. That's ten-to-the-power-of-negative-fifteen of a meter, or a femtometer. Such outrageous SI prefixes
rarely appear in fiction, and that's before we get anywhere near the scales of galaxies and subatomic particles. This is because most writers aren't that good at or are too lazy to implement mathematics, let alone the branch of calculus
. If it sounds like a number made up by a child
(Attention all yoctograms!
, septillion seconds), the writer might have actually taken it seriously.
Another example which often comes up is the idea of beings coming to our galaxy from another galaxy. While there's no reason why a writer can't
introduce beings from the nearest galaxy intent on contacting/conquering the Milky Way, there would have to be a pretty dang good reason
to travel the incredibly vast distances separating galaxies — distances which make traveling between stars seem like a little hop.
Some would consider this one of the Acceptable Breaks from Reality
. If the characters didn't travel through space at thousands of times the speed of light
, it wouldn't be very interesting, unless the focus was just the spaceship itself. Either you'd have to make the ship incredibly powerful to max out Time Dilation
and shorten the time spent from the characters' perspective, put the characters into some kind of suspended animation
(and just fast forward through their journeys), or even have entire generations of characters that would live and die on the ship
before they even reached a known extrasolar planet (meaning the audience would say They Wasted a Perfectly Good Character
or treat the new generations as a Replacement Scrappy
), and so on... If Star Trek
, for example, was realistically scaled, it'd be a lot
When adding examples, it may be wise to consider the capabilities of the faction in question. What is "unrealistic" for a low-tech harder-SF group may not be so for a high-Kardashev Higher-Tech Species
; after all, what we can do now would be outlandish to our medieval ancestors, so who's to say a society centuries if not millennia more advanced than us can't invent a "unrealistically" light yet superstrong material? On the other hand, some things are laws of physics
, not limits of technology, and the difference is an important one (any ship that expels an exhaust to propel itself, for example, functions by the Tsiolkovsky rocket equation, which is basically a special case of the Second Law of Motion—regardless of what the exhaust is or how it imparts the energy to expel it).
Two related tropes are Medieval Stasis
and Modern Stasis
, where society stays the same for thousands of years. It is a subtrope of Space Does Not Work That Way
, which features a list of tropes that try to treat space in a way that it wouldn't realistically work. See also: MST3K Mantra
, Bellisario's Maxim
, Watsonian Versus Doylist
Examples go into subpages: