One of the longstanding tropes of science fiction, going back at least to Robert A. Heinlein's Universe, is the giant slowship that forgets its culture and history in the course of the centuries-long journey across the depths of space between stars. However, Eric Flint and David Freer have taken a new view on this hoary old concept with their new novel Slow Train to Arcturus.
Rather than make a one-time journey to a single destination, Flint and Freer postulate that a slowship would find acceleration so precious that it should not be wasted at the end of the voyage. Instead, the main ship would continue to travel indefinitely, while individual habitats would be detached from it, slowed and permitted to be captured by potentially life-bearing stars. There the colonists would have the option of living in their habitats indefinitely if the star's system had no habitable planets, and will have access to the wealth of the system's sub-planetary bodies for space-based industry.
Or at least that was the theory when the Slow Train was sent from Earth sometime in the twenty-second century. It was supposed to simultaneously give a number of separatist groups a new frontier to which to escape and get some of humanity's eggs out of the single basket of the Sol system. But things relatively go as planned.
But Krentz and his colleagues from Miran don't know any of this when their astronomers detect the strange vessel moving into their system's space. They only know that this is an artifact, and that it was not built by any civilization of theirs. Naturally, they are both concerned and curious, so off they go in a spaceship of their own to rendezvous with this stranger and find out what is going on.
But things go disastrously wrong when they make their initial contact with a habitat that turns out to be violently xenophobic. Suddenly Krentz is thrust onto his own resources and into even stranger habitats.
Thus Flint and Freer also delve into another longstanding trope, one that science fiction shares with several other genres: namely, the adventure in the alien society or lost civilization. But the unique nature of the Slow Train makes it possible to visit not one but many such societies in rapid succession.
Some the reader will recognize immediately as commentaries upon certain present-day societies, such as a certain notorious dictator with the bouffant hairdo and the shades. Others seem to be the realization of the fantasies of certain more extreme elements of our own society. But amidst all the humor of cultural misunderstanding and sly cultural commentary, including a very recognizable geek inventor who had the misfortune to be born in a technophobic society, there is a very real consideration of just how well such a scheme would work long-term.
For as it turns out, every one of the habitats we meet is experiencing severe difficulties maintaining the technologies that are essential to their long-term survival. Some, such as the Neo-Nazi group we first meet, seem to have given up altogether and devolved into a war of the all against the all. Others, such as the Matriarchial Republic of Diana which provides ample opportunity for trenchant commentary on relations between the genders, are making an effort to maintain their habitat but are finding it increasingly difficult to keep up the knowledge base, and in particular a population of people with the necessary skill sets to repair the more complex machinery.
Thus, without ever harping openly upon it, Flint and Freer raise yet another age-old question of science fiction -- how large of a population base does one need in order to maintain a technological civilization? And how long can a small group, even one that set out with more than adequate supplies for a long voyage, keep complex systems working when it is not possible to replicate the system of interlocking technologies that originally created them?
Which of course brings us to yet another familiar old trope of science fiction -- the colonial world that reverts to earlier stages of technological development, perhaps even losing civilization altogether and forgetting that it did not originate on the world upon which it now finds itself, or even that it is living on a spherical world spinning in space around its sun, rather than a flat world with a bowl of sky in which hang bright lamps that light and go out as day follows night.
However, Flint and Freer have managed to weave all these ideas together and infuse them with a freshness that is at least partly the result of the alien viewpoint of Krentz, through whose eyes we first see humanity's greatest technological achievement, not as a triumph, but as an intruder not entirely welcome into the skies of a people who assume that of course every organism that reproduces sexually will start as a male, then transform into a female upon full maturity.