Kim Stanley Robinson wrote an excellent essay on generation ships — the science-fiction concept of building starships designed to take hundreds or thousands of years to fly to their destination, with generations of people living within them — and summarized all the physical, biological, and ecological problems with them that would ultimately doom such a project to failure. His conclusion is that “Earth is our only home”, which sounds depressing if you look at it one way, but really shouldn’t be, if only we could stop trashing the place.

I agree completely with that essay.

Now Kameron Hurley has written her own excellent essay in response, pointing out that there is a path towards making them viable again. I agree completely with this one, too.

If we figured out how to jettison ourselves from the Earth, we can figure out how to alter ourselves to traverse the incredible distances between stars and even galaxies. And here, then, is the difference in ideas that drives my writing as opposed to that of many other science fiction writers. I understand that space travel and expansion is just as much about altering ourselves, our attitudes, our social structures, our very biology, as it is about altering the places we choose to live.

The one problem is that word “ourselves”. Who are “we”? As Hurley says, the only way this works is if we are plastic and willing to change who we are, adapting to radically new circumstances. We can’t expect to simply put New York in a bubble and lift it off the planet — New York in space is a completely different beast from a New York planted firmly in the BosWash corridor with harbors and airports to connect it to everywhere else. The life of the city would have to change utterly.

The Puritans left England in their ships to preserve their way of life. It didn’t work. It changed everything about them in ways they could not predict, and I suspect that if we could go back in time and show the Puritan emigrants a picture of what America would become and how their descendants would live, they would react with horror and decide that there is no point in leaving after all. If your goal is to shelter your identity, your way of life, and the lives of your children, packing up and moving to a wildly different environment with unpredictable elements is probably the very worst idea you could have. If you want to define “ourselves” as a body of beliefs and ideas, well, sorry, those are extremely fragile and tend not to survive in new environments without some major transformations.

What about our biology? Look at the formation of the Panamanian land bridge and the exchange of North and South American fauna. We couldn’t possibly predict who the winners and losers would be, except, maybe, that there’d be a lot of losers. The grand champion of the invasion of North America was…opossums? Really? Come on. If they’d been sapient, those 5 meter tall phorusrhacid terror birds might have been pretty confident that they were going to kick ass and take over and rule two continents, but instead they all went extinct — as did the Astrapotheria, the Litopterna, the Sparassodonta, and other orders of big strong beasties — and it was the marsupial rat-thingies that thrived?

Hurley is exactly right that generation ships could be doable if we didn’t think of them as shells for people in transit and more as self-sustaining ecological islands cast off to grow and change, but then we have to change our notions of what constitute “us”, because for sure what arrives at a distant star a thousand years from now won’t be Americans, and may not even be recognizable as human any more. We could be building a bridge to Tau Ceti that delivers a chittering cargo of marsupial rat-thingies to a brand new world.

Is that acceptable? Is our vision of ourselves sufficiently flexible that we would consider planting a colony of unicellular eukaryotes on a distant planet to be a success? Would we be disappointed if we didn’t at least get mammals off-world, or are we going to insist on a primate exodus? We’re going to have to have an extraordinarly broad sense of identity for this all to work. Hurley seems to get that, I’d just wonder whether she’s gotten weird enough.

This was a concept I explored deeply in my novel, The Stars are Legion. Because certainly, we will change if we create and inhabit a living organism to which we are intrinsically tied. The Earth has shaped our evolution in every way, and our world-ships will no doubt do the same. Perhaps we’ll never be able to leave these ships. But propelling ourselves across the universe inside a self-sustaining world that can repair and reproduce itself solves the problems of distance and reduces the chance of ecological collapse, particularly if the worlds moved together as a legion and included independent layers of systems so that if one began to decline, another would rise. Think of it as naturally evolving back-up systems.

Exactly. People aren’t an ecosystem. It’s going to require establishing a complex, diverse assemblage of organisms to be self-sustaining, and everything will change year after year. And you aren’t going to be able to predict ahead of time how it will change, only that it will change. And the most fungible, protean, fragile elements will be the highest level bits, things like “societies”.

Those who arrive in the next star system, if they have created societies that allow them to change what we currently consider to be the intrinsically human foibles of war and strife and pettiness and bickering, will require time to adapt to a new environment. Consider how symbiotic parasites can chemically change and shape their hosts to suit them. Now imagine a ship is programmed to merge its flora and fauna with a new planet when it arrives, making the world-ship, now, into a living terraforming machine, a bacterial incubator that rapidly adapts the local environment to sustain its hosts. If symbiotic parasites can do this here on earth, why can’t we hurl something like it through space?

There are nightmares nestled in that idea.

Imagine you fill your ship with high-minded idealists, intellectuals and artists, and plan to export the very best of your culture to distant alien worlds…and by the time it gets there, it turns out that the best survivors are Republican neo-Nazis and televangelists.

Or it isn’t even people who last a thousand years in your starfaring arcology, and the survivors are all marsupial rat-thingies. But I repeat myself.

Try flipping the perspective, too. You’re having a grand time on an ecologically restored Earth, living in balance with all of nature, when a legion of ecological arks from an alien world arrive. They don’t want to exercise the cartoon SF prerogative of exterminating all humans or destroying Earth, they want to merge with us allow change to flow from the natural ecological and evolutionary interactions of diverse species. They aren’t going to kill us, no not directly, they’re going to give us an opportunity to adapt and change, like all good species. Never mind that these kinds of interactions are always catastrophic for some. We send probes up to the oncoming giant space island to figure out what we are going to face, and the astronauts look inside and say, “My god, it’s full of marsupial rat-thingies!”

Or Republicans and televangelists. But again, I repeat myself.

But I am looking forward to reading Hurley’s The Stars are Legion. Maybe I’ll get to it this weekend.