Some stories require more suspension of disbelief than others. Having just completed reading a (mostly) scientific survey of the origin of the universe, including a brief discussion of the multiple worlds hypothesis, I was less ready than usual to read The Long Earth by Terry Pratchett and Stephen Baxter. But a good yarn can captivate me anyway, and this one did. The Pratchett/Baxter collaboration is one of the more fortunate combos in the sci-fi world today.
Most science fiction is based on asking, "What if this or that were different…?" Here, it is, "What if there really are a multitudes of parallel Universes, and what if there were a way to 'step' from one to another?" In this novel, the word 'step' takes on a whole new meaning. The authors thought this through quite thoroughly, and a few of the important implications include:
- Evolution played out differently on different Earths. Sundry hominids, that can step between worlds, could then be behind legends of fairies or elves or trolls.
- Stepping may be an evolved skill.
- With possibly infinite real estate suddenly opened up to humanity, how will it affect politics and economics? Just consider if known gold mines can be re-mined many times over…
- People would vary in their ability to step, once it is unleashed. Suppose it is easy and quick for some, tricky (requiring technical help) and slow for most, and impossible for some. Class warfare, anyone?
By the way, I read somewhere that the approved directions for a fourth dimension are Ana and Kata. As prefixes, "ana" means to build up, as in anabolism, and "kata" means to break down, as in katabolism; they are the two halves of metabolism. Of course, any pair of antonyms one might choose instead of East and West are going to have extra baggage, so perhaps the authors were wise to stick with East and West.
The stepper device is powered by a potato with dissimilar metals stuck in it, forming a crude battery. All commercial batteries contain iron, so none can be used. However, I've made potato batteries; the usual way is to use a piece of heavy copper wire and an iron nail. Obviously, some other metal has to be used in a stepper's potato battery. Which one it is, is never mentioned. I wonder why iron is discriminated against, though.
The action is set just far enough in the future, about 20 years, that Moore's Law is likely to have produced a modest-sized computer that could contain a downloaded, or in this case, reincarnated, human soul. A Tibetan who died at just the right moment takes up residence in a newly-booted-up organic computer. Once it is verified that he is really "in there", and thus it would be murder to turn off the computer, he gets the backing of a powerful magnate, is paired up with a young man who needs no technical help to step, and can endure rapid stepping (most can't). They go on the adventure of a lifetime, into the High-Meggers, worlds a million steps away and further.
Along the way, the authors get to try out an extreme evolutionary hypothesis: Suppose a pre-DNA form of life became dominant. How would it evolve, and what would be the result after 4+ billion years? Further, would there be a way for modern humans to communicate with…whatever it is?
These ingredients have produced a tasty ragout of a book, a great read. And it is a clever place to begin a new series, if the authors are so disposed. After all, with a few million newly-discovered Earths to choose from (and that is just to the "West"), they'll never run out of almost-ordinary situations they can tweak to their heart's content.