Relativity! Extremely well supported by the evidence, and extremely inconvenient for SF authors who want jaunts to the galactic core to be as easy as popping down the road. Given a universe so large that light takes as long as anatomically modern humans have existed to meander across a single galaxy, combined with a very strict speed limit of C, and you face a cosmic reality that makes many stories authors might want to write quite simply physically impossible. So… what are hardworking science fiction authors to do?
Disregard the Issue
By far, the most popular option is to ignore the issue or actively deny that it is an issue. Maybe Einstein divided when he should have multiplied (he didn’t). Perhaps light speed can be surpassed given sufficient will (it can’t). What if some miracle material for which absolutely no evidence exists could facilitate superluminal travel? (More likely, such materials are simply non-existent.)
One might excuse an early example, such as Doc Smith’s The Skylark of Space, on the grounds that the novel was written early enough that relativity had not yet earned by weight of evidence the overwhelming consensus it now enjoys. I don’t know if a physicist of that day would have agreed, but they might have admitted that Smith’s handwaving facilitated a thrilling tale of galactic-scale interstellar travel uninhibited by physics or indeed, basic literary values.
More than a century of research suggesting that Einstein was right hasn’t stopped authors from imagining faster-than-light drives. Julia E. Czerneda’s 2001 In the Company of Others features convenient and affordable faster-than-light travel, not to mention an abundance of easily-terraformed planets suitable for human exploitation. The cost: if it’s easy to explore the Milky Way, it’s possible to encounter a lifeform one would have been better off never contacting. In this case, that would be the Quill, a seemingly harmless lifeform that by the novel’s beginning has wiped out human life on all colony worlds.
Accept the Universe the Way It Is
Yes, that means giving up dreams of galactic communities where a gentle being can send a message to Sirius before breakfast and get a reply by lunch. But… embracing the universal speed limit and scale only rules out most interstellar adventures. Fun in our Solar System is still possible! Well, to backtrack a bit, relativity does not rule out interstellar adventures, just as long as one accepts that such endeavors will be inherently difficult and time consuming…
Arthur C. Clarke’s 1975 Imperial Earth, set during the American quincentennial, dispatches Duncan Makenzie from his native Titan to Earth. The ostensible reason for the trip is diplomatic outreach between the US and resource-focused Titan. Side projects include saving Titan’s economy from being destroyed by an impending drop in demand for their primary export and dealing with Duncan’s excessively fraught romantic life.
Ari North’s 2020 webtoon/graphic novel Always Human is likewise set in the not-too-distant future, one in which most but not all people have access to life-enhancing body modifications. Austen is one of the unlucky few; she has an autoimmune disorder that precludes using mods. Sunati, smitten with the imaginary Austen she has invented based on a few brief public transit encounters, successfully woos Austen. Will the relationship prevail or is it doomed by inherent communication issues and career choices?
Yes, there’s travel within the Solar System in this webtoon/novel.
Move the Stars
Adherence to scientific plausibility would seem to rule out interstellar travel, at least of the convenient variety. There is a loophole. Use settings in which one or more stars are closer to us than they are at present, which is entirely possible because STARS MOVE.
In John Brunner’s 1982 Catch a Falling Star, astronomer Creohan observes a star making a beeline for the Solar System. The consequences of a close encounter could be catastrophic. Inconveniently for Creohan, his Earth is a decadent one—even had it the means to deal with the crisis, it does not appear to have the will.
More recently (and yet somehow still decades ago) Donald Moffitt’s Orientalist 1989 space opera series Mechanical Sky showcased an ambitious sultan whose solution to interstellar distance was to exploit Moffitt’s comprehensive misapprehension of basic physics certain curious aspects of near-light travel to move the stars themselves. Even a single cubic light year is a very large volume of space, more than enough to house a vast number of systems.
Time Dilation
Relativity itself offers a useful coping mechanism in the form of time dilation. The duration of a trip varies according to the observer. When relative speeds are low, clocks will agree. A traveler who travels close to the speed of light or at the speed of light will experience less time than that measured on Earth. The catch is that travelers who return home will find worlds transformed by time.
The golden age of Bussard ramjets was filled with such stories. In Larry Niven’s 1976 A World Out of Time, Jerome Branch Corbell, a reincarnated 20th century man, hijacks the Bussard ramjet with which he has been entrusted and takes a jaunt to the core of the Milky Way and back. An encounter with the black hole at the core of the galaxy sees Corbell return to the Solar System millions of years later, time its inhabitants have used to dramatically alter our home system.
Increase Lifespan
Finally, perhaps the issue isn’t that star travel is inherently time-consuming. Maybe the real problem is that humans are fragile mayflies. Increase lifespan significantly and voyages once far longer than any reasonable lifespan become, if not practical, then at least achievable.
Consider Linda Nagata’s 1998 Vast. Not only do its characters inhabit a sub-light starship far superior to any we might now build, but they have access to life-extending technology that can, under the right circumstances, make death itself a temporary inconvenience. Given the hostility of the galaxy they are exploring, such life-extension technology is invaluable.
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These are just a few of the options available to authors who want to acknowledge the light-speed limit while still crafting thrilling space adventures. No doubt I overlooked or didn’t have space for some ingenious alternatives. Feel free to mention them in comments below.
In the words of fanfiction author Musty181, four-time Hugo finalist, prolific book reviewer, and perennial Darwin Award nominee James Davis Nicoll “looks like a default mii with glasses.” His work has appeared in Interzone, Publishers Weekly and Romantic Times as well as on his own websites, James Nicoll Reviews (where he is assisted by editor Karen Lofstrom and web person Adrienne L. Travis) and the 2021, 2022, and 2023 Aurora Award finalist Young People Read Old SFF (where he is assisted by web person Adrienne L. Travis). His Patreon can be found here.
