I’ve been a big fan of the Canadian science fiction writer Karl Schroeder ever since I came across his Permanence in 2003. His Centauri Dreams essay explaining the thinking behind his new novel Lockstep, which makes use of cyrogenics to simulate the social effects of faster-than-light travel,
Creativity under constraint is the best kind of creativity; it’s the kind that really may take us to the stars someday. In this case, by placing such mutually contradictory — even impossible — restrictions on myself, I was forced into a solution that, in hindsight, is obvious. It is simply this: everyone I know of who has thought about interstellar civilization has thought that the big problem to be solved is the problem of speed. The issue, though (as opposed to the problem), is how to travel to an interstellar destination, spend some time there, and return to the same home you left. Near-c travel solves this problem for you, but not for those you left at home. FTL solves the problem for both you and home, but with the caveat that it’s impossible. (Okay, okay, for the outraged among you: as far as we know. To put it more exactly, we can’t prove that FTL is impossible any more than we can prove that Santa Claus doesn’t exist. I’ll concede that.)
Generations of thinkers have doubled down on trying to solve the problem, unaware that the problem is not the same as the issue. The problem — of generating enough speed to enable an interstellar civilization — may be insoluble; but that doesn’t mean the issue of how to have a thriving interstellar civilization can’t be overcome. You just have to overcome it by solving a different problem.
The problem to solve doesn’t have to do with speed (or velocity, for you purists), but rather with duration.
Enter Lockstep. In the novel, all worlds, all spacecraft and all habitats participating in a particular civilization use cold-sleep technology “in lockstep:” the entire civilization sleeps for thirty years, then simultaneously wakes for a month, then sleeps for another thirty years, etc. All citizens of the lockstep experience the same passage of time; what’s changed is that the duration of one night per month is stretched out to allow time for star travel at sublight speeds. In the novel I don’t bother with interstellar travel, actually; the Empire of 70,000 Worlds consists almost entirely of nomad planets, wanderers populating deep space between Earth and Alpha Centauri. Average long-distance travel velocity is about 3% lightspeed, and ships are driven by fission-fragment rockets or ‘simple’ nuclear fusion engines.
The result is a classic space opera universe, with private starships, explorers and despots and rogues, and more accessible worlds than can be explored in one lifetime. There are locksteppers, realtimers preying on them while they sleep, and countermeasures against those, and on and on. In short, it’s the kind of setting for a space adventure that we’ve always dreamt of, and yet, it might all be possible.