The Long Earth - Terry Pratchett & Stephen Baxter

I'm always nervous about collaborations between a beloved author and one I've never heard of before, but as usual I should just trust Terry Pratchett to know what he's doing. Also, I appear to be living under a log to never have heard of Stephen Baxter and now intend to go hunt down his other novels.

The idea behind The Long Earth is that there are a possibly infinite number of alternate versions of Earth, each only as far as a thought away. Up until very recently only a very few people were able to step between them, but now the schematics for a "Stepper", a device which allows one to step between worlds, has been published on the internet, and suddenly everyone is Stepping. Except for the few who can't. Also, iron does not move between worlds for reasons no one understands.

Joshua Valienté is a "natural stepper", and unlike those who need a device in order to Step, he doesn't get nauseous as he steps from one world to another. This makes him an ideal companion for Lobsang, either a sentient computer or a Tibetan motorcycle repairman reincarnated inside a computer, who plans to travel as far across the long earth as possible. There are a few other characters who stay closer to home, allowing us to see what happens to society when people can step pretty much anywhere they please. What happens to crime when theft is unbelievably easy, but there is enough space and resources for everyone? What happens when your gold supply becomes effectively infinite? Why farm when there is enough space for everyone to enjoy a hunter gatherer lifestyle?

The social implications of The Long Earth are fascinating, but by far the most interesting bit as far as I was concerned involved the alternate versions of Earth. The landscape changes slowly as Joshua and Lobsang travel farther from Datum Earth, and this does appear to be the only version of Earth which produced humans, but there are other sentient beings out there which are likely the basis for our legends of trolls & elves. But it is the landscape itself that I find the most fascinating, the unfolding of different possibilities.

Overall this felt like an introduction to the concept of the Long Earth, setting the stage for an infinite number of possible stories and I'm very interested in seeing where Pratchett & Baxter take this. Step Day is a singularity with huge potential, and it wouldn't surprise me if other authors wanted to come play in this particular sandbox.