From 1950 to 2005, our beloved planet gained a whopping 4 billion people, a more rapid population growth than it has ever seen or is projected to see in the near future. Fears about using more resources than the Earth can afford to give permeate both the world of science and the world of politics. Cities grow ever denser, nibbling away at farmland and natural habitats. In many ways, it looks as though humanity is simply running out of room.
In The Long Earth, British sci-fi/fantasy virtuosos Terry Pratchett and Stephen Baxter imagine a scenario in which these anxieties are no longer relevant: access to unlimited Earths, entirely free of humans.
The possibility of other universes is not so far-fetched according to proponents of various multiverse theories (although it is certainly far-fetched according to their critics). And this great “what if” has given science fiction plenty of mileage, inspiring films like Another Earth and Donnie Darko, as well as episodes of Star Trek, Doctor Who, and Buffy the Vampire Slayer.
In The Long Earth, Baxter and Pratchett tap into the potential of this elegantly simple jumping off point, but add a twist which makes the scientific and cultural implications of their story particularly compelling: the endless parallel earths, named “the Long Earth,” are empty. There is no other you, and there is no alternate history of humanity—the evolutionary progress of these infinite earths diverged eons before you were born.
The “science” of their story focuses largely on the evolution of the millions of earths, exploring the ways flora and fauna or even the shape and landscape of the planet might have developed differently. Some differ only slightly from our earth, the Datum Earth, hosting a handful of unusual species that would have been wiped out by humanity. Others are wildly divergent. One lacks a moon because the meteor strike responsible for it never happened, another is almost entirely covered in water, another is home to descendants of dinosaurs who were never destroyed by a catastrophic event. For each of these earths, fleeting though they are in the course of the narrative, Pratchett and Baxter prove their attention to detail by basing their fictional earths on substantial scientific fact.
The narrative theme that strings all these worlds together is a sort of manifest destiny, expansion into the unknown. When humans are given the tools to “step” to these other worlds by making simple devices (powered by something as easily obtainable as a potato), they find little reason to stay on the crowded, competitive Datum Earth. The unlimited worlds have more than enough room and resources for anyone savvy enough to start a new life from scratch. National governments, though they claim the land on the other earths that corresponds to their own, have no way of actually enforcing laws beyond the few worlds to the “East” and “West” of the Datum, so small parties are able to strike out and build new communities with almost total freedom. These communities find their personal earths generous, almost utopian, and while the Datum Earth suffers from economic and social unrest, the pioneer communities find that, away from dense cities and scarce resources, crime rates go down and morale goes up.
But not everyone on the Datum Earth is thrilled by this opportunity. While some people are “natural” steppers, able to step from world to world without a device, others are unable to step at all, with or without a device. And in this unfortunate group, Pratchett and Baxter return to the theme of evolution. In one of the book’s most chilling scenes, a politically radical leader argues that the ability to step is the next stage of human evolution, likening non-steppers to Neanderthals. But rather than concluding that humanity needs to allow itself to progress, he urges the new Neanderthals to eradicate their successors: “You think I’m a Neanderthal? You think I’m gonna make the mistake they made? Are you gonna let these mutants take over God’s good Earth? Are you gonna submit to extinction?”. In this way, Pratchett and Baxter achieve a certain narrative unity—questions relevant to the natural world are also relevant to the social sphere.
In a novel so focused on the natural sciences, making AI a major character might seem out of place. But Pratchett and Baxter take the risk with Lobsang, a nearly omnipotent computer intelligence who partners with a particularly gifted natural stepper to venture as far into the Long Earth as he can. The book spends most of its time following their journey, and Pratchett and Baxter allow the characters and the reader to speculate over whether Lobsang is human at his core, as he says.
Questions about AI might seem irrelevant to the book’s plot and setting, but Lobsang actually makes sense in the context of evolution. In the Long Earth, humanity is examining other worlds to discover how their past might have turned out differently, and wondering whether access to the Long Earth represents the next stage in their own progression as a species. Lobsang might represent a more far-reaching evolutionary advancement. After all, he claims he was once a Tibetan man, and his computerized self is simply a prosthetic for a surviving human consciousness. What if the ability to “reincarnate” into AI was more widespread, like “stepping” has now become?
The fact that Pratchett and Baxter get away with an unlikely combination of sci-fi tropes in The Long Earth speaks to their mastery of the genre. What makes this book successful is the same thing that makes all the great sci-fis great: starting with a simple but slightly out-of-reach scientific possibility, making it reality, and then following the ramifications like a domino chain. They dive into the implications for science, for politics, for culture, and for individuals from differing backgrounds and spheres of life. This is sci-fi as it should be: imaginative, intriguing, and above all, relevant to its time.
Reviewed by Lauren Klepinger