We last heard from Karl Schroeder in his essay Creative Constraints and Starflight, published here back in March. Schroeder was describing his new novel Lockstep, whose ingenious plot is in the service of a daring idea: If we are limited to speeds well less than that of light, can we still find a way to achieve the kind of deep space civilization we’ve seen depicted in so much science fiction? That would include travel to far places within single human lifetimes, trade with colony worlds, and much of the panoply of what is sometimes called ‘space opera.’


Schroeder’s solution is ingenious and challenges the preconceptions most of us bring to interstellar flight, which is why I want to return to Lockstep this morning. I had read a pre-publication copy late in 2013 and found that it triggered some incipient thoughts on how we relate to time that I needed to work out. In particular, not only in Karl’s work but in Neal Stephenson’s and, to an extent, in Alastair Reynolds’, I’ve found a creative re-casting of our relationship to time and how we measure it off in terms of a single human lifetime. Exactly what is ‘subjective’ time, and is there a specific way it should relate to ‘objective’ time?

The question Schroeder forces upon us is whether time is best measured as a clock-driven passage of minutes, hours and days (I call it ‘objective’ time while acknowledging its malleability in the form of spacetime), or as an accumulation of life experiences that can be separated from this objective time. In the world of our experience, we may think of time as a substrate through which we move — we have so many years in our lives and the clock is always ticking in the background. In the world of Lockstep, that ticking can be suspended. Adjusted. The human experience of time is what it has always been, but the world around it is accelerated.

Benefits of Adjusted Chronology

We’re in a world where suspended animation is routine and about as eventful as getting into bed for a good night’s sleep. You might sleep a day, or a year, or in the case of young Toby McGonigal, the book’s protagonist, a breathtaking 14,000 years before waking up. While conventional, day to day life goes on elsewhere, the Lockstep worlds are those that have entered into a contractual arrangement to use suspended animation to stay synchronized. A 360/1 schedule, the primary one in this culture, keeps people suspended for 359 months out of every 360. It’s this last month in which they awake and get about the business of civilization.

Karl has already described this scenario in our pages and we’ve had discussions about its pluses and minuses. But let’s look back and review for a moment what a society like this gets from this strange arrangement. You can see that the so-called ‘fast worlds’ — the inner planets, for example, living as we do today without recourse to suspension — suffer from constraints that the tiny outer worlds in the far Kuiper Belt and beyond don’t endure. As Toby gets used to the world he has awakened into, he marvels at its fecundity. “We’re in the middle of nowhere between the stars but this place seems as rich as Earth. Though that can’t be.”

But of course it is, for reasons he comes to learn, just as he learns the key role his own family has played in this outcome. Schroeder describes all this in terms of computer technology. The locksteps, small worlds synchronized on their schedules with each other, form a synchronous network, with each node acting at the same time. In other words, imagine a large number of tiny, isolated worlds in the Oort Cloud, all sending out their cargo (including passenger ships) on the same schedule. Tuning the ‘frequency’ properly can turn desolate outposts into economically viable societies, for reasons Schroeder is careful to explain in a book where the consequences of this tuning are extremely well thought out and depicted with real panache.

There were tiny colonies that didn’t own even a chunk of cometary ice but harvested the impossibly thin traces of gas found between the stars using modified magnetic ramscoops. In an abyss so empty that there was only one hydrogen atom per cubic centimeter, the scoops filled their vast lungs like baleen whales filtering tenuous oceanic plankton. It could take them decades to fuel a single fusion-powered ship with enough hydrogen to visit their nearest neighbor. Yet even these little starevelings could contribute to the wealth of Lockstep 360/1, because its clock ticks were slow enough for them to keep up.

Automate your industry and go to sleep. When sufficient time has passed to allow the accumulation of a viable amount of resources, you emerge to engage in the necessary trade with other worlds like your own, worlds on the same schedule. A richer world might join a faster lockstep since it could manufacture goods at a greater clip, but even the poorest world has the chance to be part of a functioning civilization at a slow speed. Travel between the worlds takes a lot of time — remember, we’re in a world where Einstein’s speed limit still applies — but on a 360/1 schedule, you might travel half a light year while ‘wintering over,’ as Schroeder calls it.

That makes long periods of suspended animation a genuine plus for those with a yen to engage with the greatest number of the more distant worlds. A wintering over journey at a 36/1 schedule can have a certain number of destinations within range, but a 360/1 lockstep can deal with a thousand times more worlds. Doubling the distance you can travel opens up more distant worlds scattered through three-dimensional space, and a kind of empire can emerge that has resonances with everything from Doc Smith’s clanky space tales to the world of Star Trek.

Differentiation of the Culture

But back to the human experience of time, which is what fascinates me about what Schroeder is doing here. The understandable immediate reaction to a lockstep is that it simply slows the pace of discovery — how to progress when people only wake up briefly every thirty years? But the question is, progress on whose terms? For those whose lives take place within the lockstep, the framework of time outside has been abandoned. They still can expect to live their allotted lifetime, but it’s a lifetime that might take in vast stretches of time during which, to civilizations not in a lockstep, their own empires might rise and fall as the lockstep goes about its way.

All he could really sort out was that humanity and its many subspecies, creations and offspring had experienced many rises and falls over the aeons. Since they had the technology, and lots of motivations, people kept reengineering their own bodies and minds. They gave rise to godlike AIs, and these grew bored and left the galaxy, or died, or turned into uncommunicative lumps, or ran berserk in any of a hundred different ways. On many worlds humans wiped themselves out, or were wiped out by their creations. It happened with tedious regularity. The only reason there were humans at all, these days, was that there were locksteps.

I think this is fascinating — the lockstep as a backup, a repository for the entire species. Schroeder continues:

They served as literal freezers, preserving ancient human DNA and cultures. All kinds of madness might descend upon the full-speed worlds circling the galaxy’s stars — expansions, contractions, raptures, uploading, downloading, mind control, and body-swapping plagues (quite apart from the usual wars, dark ages and terraforming failures) — but everybody ignored those useless frozen micro-worlds drifting between the stars. Their infinitesimal resources and ancient cultures held no interest to the would-be gods of the inner systems. So once those would-be gods had wiped themselves out, the telltale silence from formerly buzzing stars would alert this or that lockstep, and they would send some colonists back. A few millennia later, the human population on Earth and the other lit worlds would again number in the billions or trillions, and some of those would return to the locksteps…

It’s a way of living deep into the remote future, this lockstep, and it sets up levels of civilization that work at different rates of time, from those who continue, as we do, to live one day for every day that passes, to those who adjust that schedule according to the needs of their environment, which out in the Kuiper Belt or Oort Cloud can be quite different. Freeman Dyson has often talked about the biological differentiation that will occur in our species as we adjust to varying conditions moving outward from the Sun. Schroeder is describing a chronological evolution that takes place as entire cultures become disconnected by their choice of calendars.

So how do you feel about it? Is sleeping for thirty years a waste of time? Or is a lockstep a way to continue to live your entire life while what gets ‘burned’ is time that is of little value to you? I’ve always found Karl Schroeder’s work provocative, but Lockstep is a book that keeps coming back to me at odd moments, as I wonder whether people would voluntarily enter into these arrangements in a world where suspended animation was easy, and whether the benefits of a lockstep to the teeming worlds on the Solar System’s edge would outweigh the break from the culture that had spawned the original colonists. I don’t have the answers here, but good science fiction, and this is very good science fiction, asks extraordinarily provocative questions.