668. Century Ships

Joachim Boaz at Science Fiction and Other Suspect Ruminations has been running a series of reviews on century ship stories. He does a good job, even providing links so you can read the story itself before or after reading his review. I’ve read two of them, both story and review, picked out because they were by Brunner and Ballard.

Century ship stories are an extreme version of slow starship stories, that is, stories about exploration in ships which do not travel faster than light. Century ship stories assume that the people who start the journey will not live to complete it. It will be completed by their descendants who, when they arrive, will never have lived anywhere but on the ship.

That sounds like a recipe for disaster, and it typically is. A reversion to barbarism along with a superstitious belief that nothing outside the ship actually exists is a common trope. The original Star Trek used it in For the World is Hollow, and I Have Touched the Sky.

I first encountered century ships before I reached high school in The Forgotten Star, a top notch juvenile which has, ironically, been forgotten. It takes place in our solar system, before star flight; the young heroes discover that Ceres isn’t really an asteroid, but a century ship from elsewhere.

The first time I read a century ship story told from the occupants’ viewpoint was Heinlein’s Orphans of the Sky. It was such a dreary presentation of the “we forgot this is a starship” trope that I never returned to it, and it pretty much put me off century ship stories for a long time.

On the other hand, slow — but not that slow — starship stories are my bread and butter. They take relativity more or less seriously, and offer all kinds of complications through the slowing of time at the approach of lightspeed. Heinlein did it well in the juvenile Time for the Stars. Other authors had milked the concept for its considerable potential for weirdness.

At nearly the speed of light a trip to the stars will seem quick, no matter how many years pass back on Earth, but getting up to the speed of light is an issue is two senses.

First, it will require power on the order of what would come from the total annihilation of matter. This generally requires a MUD (magical unexplained dingus). Slipstick Libby invented one, but usually Heinlein got there by torch ship (what a wonderful name!), a MUD he never bothered to explain. When I needed that much power in Cyan, I invoked Lassiter’s Anomaly as an ersatz explanation. This gave my core ships a nice philosophical underpinning, like E. E. Smith’s Bergenholm which cancelled inertia, but core ships are still MUDs.

Given the power, however you get it, relativistic starflight still has the problem of acceleration time. True, time slows down at near lightspeed, but you have to get there first. If you are an honest writer who takes the time to look at Einstein’s simpler equations, you will realize that it takes a long time to approach lightspeed at an acceleration that wouldn’t squash a human flat.

I did the math for Cyan, and it turned out that a one-way trip to Procyon — accelerating at one gee, coasting, then decelerating at one gee — took three years subjective while twelve years passed on Earth and Cyan. That’s a six year round trip for the ten crewmen, which calls for a lot of games of chess and a lot of intimate human interactions. If you’ve read Cyan, you know what I mean.

As a side note for new writers looking for a useful tip, that coasting stage is a near-freebie. A ten light year or a hundred light year trip would take about the same subjective time, but the time differential between the crew and the folks back home would become immense.

Later in the book, sending colonists took a whole different set of calculations. Accelerating to half the speed of light takes a tiny fraction of the fuel needed to accelerate to near lightspeed, so the colony ships were even-slower-starships, though still not nearly as slow as century ships. Call it twenty years, one way.

How do you get tens of thousands of people into a small space and keep them from killing each other over twenty years? Freeze them. Given the technology of 2107, that meant a twenty percent loss of life among those who chose to go.

Cold blooded? (Forgive the pun.) Not when you consider the conditions they were fleeing.

While the colonist were on their way toward Cyan, a group of beltmen (denizens of the asteroid belt) were also planning an escape. They were already used to living in space; many of them were born there. A long slow trip in a small habitat did not deter them, but the eighty year voyage to Sirius had a lot of unintended consequences. Not quite a century ship perhaps, but close enough.

Of course if you have been following this blog during the last six months you realize that I am talking about Dreamsinger, the sequel I am working on now.

Further down the to-write list is a sequel to the sequel to A Fond Farewell to Dying which concerns a hyper-century ship built around memory taping and a few frozen stem cells. That one doesn’t turn out the way its originators planned either.

I guess the trauma of reading Orphans of the Sky at a tender age hasn’t completely put me off century ships after all.


2 thoughts on “668. Century Ships

  1. thebigbuddy

    The SF novelist Alastair Reynolds is well known for generation ship stories, especially in his Revelation Space novels, in which humans travel between star systems on ships called “lighthuggers”: 4km-long behemoths that can carry a quarter of a million passengers and take up to two years to accelerate to .99c, where they rely on relativistic time dilation and cryopreservation to “shorten” journeys that can take decades or centuries.

    Reynolds, a physicist, uses the concept of advanced ramscoops: Drives that suck hydrogen from the interstellar medium into a maw in the ship, then subject the hydrogen to reactions that power the ship’s drives. It’s good, feasible science, and it’s entirely possible the first human journeys outside of our system will be powered that way because it does not require a ship to carry fuel for its primary drive.

    One of the most interesting concepts is that, when passengers embark on those voyages, they are already relying on information that is decades old at the very least, and can arrive to find very different worlds than the ones they expected to find.

    Then there are the social and political aspects. Reynolds’ novel Chasm City is about the crew of a flotilla of generation ships, and the incredible resentment they feel toward the wealthy passengers who sleep through the journey as crew members are born, live and die aboard those ships

    I’d also recommend Kim Stanley Robinson’s Aurora, which is about a generation ship crew en route to an idyllic colony, and deals heavily not only with the psychological challenges, but also the remarkably difficult balance of maintaining a closed ecosystem for more than 100 years when there is no hope of resupply and no way to obtain more resources during the journey.

    The technical challenges are fascinating and enormous, and in some ways are as interesting as the psychological issues that stem from locking thousands of people in a closed environment for generations.

    Thanks for reminding me of Orphans of the Sky. It had been recommended to me a few years ago and I’d forgotten about it.


    1. sydlogsdon Post author

      I like ramscoops, but I had more than one fish to fry. After a lifetime of watching “scientists” more disconnected from reality than novelists as they came up with a proliferations of untestable theories, I wanted to kick them in the slats with Lassiter’s anomaly which nobody understands but which does stand up to testing.

      I also like the “old data due to lightspeed” concept. A lot of stories could be generated out of that. My somewhat similar issue is that when I started Cyan back in the eighties, exoplanets were essentially unknown. Pretty soon, if not already, a writer won’t be able to put planets where he wants them in the nearby galaxy. I haven’t checked lately, but my three sets of man-visited exoplanets may already be known to be in the wrong places.

      My reference to Orphans of the Sky was not a recommendation, but a warning. However, I haven’t read it for decades so maybe it is better than I remember.

      If you didn’t follow up my link to Boaz, here is another
      It takes you directly to his extensive list of century ship stories.



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