Science of Discworld

The title of the book is a contradiction in terms…there is no science in or on Discworld. There is magic and a certain relentless logic all its own, plus a respect for scholarship and learning, but there really isn't science. At least not so's you'd notice. It does have mathematics of course, with the greatest mathematician in the world being a camel (see Pyramids), who rather surprisingly really, bears no resemblance whatsoever to mathematician Ian Stewart, one third of the author of Science of Discworld. Another third is biologist Jack Cohen (JC), and the final third of the triumverate is ex-journalist Terry Pratchett (TP), in whose head Discworld may be said to reside (if it isn't out there, somewhere, that is)

So, how do three such disparate folk get to write a best-seller? "We meet up for a chat and a pub lunch several times a year. Inspired by The Physics of Star Trek, I raised the possibility of something similar related to Discworld. We then thought about this a lot and decided that (a) there is no science on Discworld and (b) [six months later] the answer is to put some there" explained Ian Steward (IS).

While Ian and Jack might be considered, by most to be purely scientists, who write science stuff, Ian has written quite a lot of SF, as well " 19 short stories in fact" and the next book collaboration between IS and JC is half written and is an SF novel tentatively called Wheelers. "The real fun is watching your characters take on their own life and head off in directions you didn't expect".

As the book itself says 'There is no science on Discworld. Discworld runs on magic and on narrative imperative. Things happen because people want them to, or the demands of the story mean that they have to. Science is different: it runs on rules.'

"Which leads to the first question. The differences between magic and science are highly illuminating, and Discworld is the perfect framework for a 'What if' discussion of science --- a well-established, self-consistent universe that can be used to ''compare and contrast'. It was a book that had to be written. The narrative imperative of Roundworld ---our universe ---demanded it. Terry had a universe to play with, and Ian and Jack wanted to play. Jack had known Terry since before he was famous, and he introduced Ian at one of the annual Novacon science fiction conventions.

"When The Physics of Star Trek appeared, and found an audience, we quickly realised that the world was licking its figurative chops for The Science of Discworld. There was only one problem, as Terry immediately pointed out: there is no science of Discworld. A Science of Star Trek treatment of dragons, for instance, might involve the chemistry of methane biogenesis and combustion, and the genetic engineering of asbestos-lined intestines.

"But, on Discworld dragons do not breathe fire because of chemistry and genetics: they breathe fire because that's what dragons do.

"The art of the science writer, of course, is to overcome minor expository obstacles like this. It took only a few months to find the obvious answer: since there was no science on Discworld, we had to put some there. Instead of producing a scientific commentary on existing events in the Discworld canon, we had to write a fantasy/fact fusion in which an unfolding story of some wizardly brand of science was interlaced with a popular science book. Terry would have to tailor a genuine Discworld short story.

"We soon thrashed out a rough skeleton of the plot. One or more of the wizards at

Unseen University must set in train The Roundworld Project --- a magical containment field about the size of a football, thaumically engineered to keep magic out. Within that field, science would happen instead of magic, with the wizards looking on baffled. The space within the field, of course, would be virtually unlimited - only its outside would be small.

"That was the framework, but what was the detail? We had to devise a plot that was flexible enough to evolve as the writing proceeded. Fortunately we had plenty of common interests, and over the years we'd discovered that on many questions we shared a common attitude. That helped a lot: it meant that we could (mostly!) trust each other.

"We began by brainstorming likely areas of science --- superconductivity and Troll brains, the ecology of dragon husbandry, the aerodynamics of broomsticks... We considered and discarded numerous scenarios. The scientific story crystallised into an evolutionary history of the Earth, starting from the Big Bang and the formation of the solar system, and continuing with evolution and the appearance of human beings. "Jack sketched out a list of scientific milestones, about a paragraph for each. ("The big extinctions, 'cos I happened to have the book around "JC) Terry took that, and when his bit was about half done, and the rest existed in outline, Ian and Jack went to work on the science. They broke Terry's story up into short sections, each containing at least one major scientific 'hook' --- neutron stars, bacteria, but also more philosophical things like 'coincidence'. Then they wrote commentaries on those topics, using a method that had evolved for previous joint books.

"After various discussions in the local pub Jack would generate a set of (often cryptic) notes. To begin with, none of this was sent to Terry, because he wanted to 'listen to the wizards' and let the plot follow its own Discworldly logic. But, once his story line had gelled, Ian and Jack began e-mailing drafts to him -chopped up fantasy plus interwoven science. This wasn't totally straightforward, since Ian used a Mac, Terry used a PC and they both preferred different wordprocessing packages.

"However, from this point on the book grew rapidly, until we had a fairly complete draft that was 20,000 words too long. We then held a joint meeting of all three of us, in which we tore it to bits and reassembled it, asking questions like 'What's it about anyway?

"IS, armed with copious notes, went into purdah and did a major editing job. Meanwhile Terry, assured that whatever IS did wouldn't cause any new problems for his bit, rewrote the fantasy story to smooth transitions and set the scene. After another iteration of this process, some rearrangement of the order of chapters, and changes in the break-points of the fantasy story, we had a virtually final manuscript. Terry now went over the whole thing, fantasy and fact, administering a 'sprinkling of fairy dust'. Jack and Ian read the result, made a few consequential changes to their bit (but only where absolutely necessary) and told TP what they had done so that he could make sure there was no knock-on effect on what he had done. And that was that"

How well did the three find that they worked together - three authors could be a recipe for a disaster. Ian Stewart again explains "We considered TP to be the senior author, whose reputation was on the line if the book was a flop, so he had the power of veto. However, he never had to use it. I did tend to put in a lot of physical science, which TP took out again as 'its quantum, isn't it?' but I didn't feel too bad about this…although, late in the day we did edit out a few things that one or other of us was rather attached to, as the 'sprinkling of fairy dust' was added at the end.

"We've known each other long enough, and talked to each other often enough, to feel confident that we view the world in very similar ways."

"Our relationship was pretty much sweetness and light" added JC

Okay, so everything was moonlight and roses amongst you all, but why write such a book in the first place. Isn't such a book merely cashing-in…riding on the coattails, so to speak, of a successful product - Discworld?

"We wanted to write a book which made use of the very positive fan base for Discworld as a way to promote and explain science," ("produce a really enlightened pop-science book explaining science to those fold who were caught on Discworld -but not The Physics of Star Trek -being clever on a scientific pedestal" - JC) to make use of our fan base of science fans to introduce a new group to Discworld, and have lots of fun writing the thing." While TP often claims that writing is the most fun he has with his clothes on, JC comments "Science of Discworld was more fun than I'd had out of bed for a year".

So, why did they go into science (TP again claims that it was an indoor job with no heavy lifting) Ian - " It seemed like a good idea at the time" while Jack elaborated " I loved animals, all kinds, from being a kid; if it had meant standing on my head (or, preferably someone else's) for a year I'd 've done that. I've had such fun all my life, doing bench research into important things like hair growth, sperm numbers, and been encouraged to teach bright young minds…If you want to play around with their bodies they put you in prison, but it's much more exciting mucking about with young minds…all but two of the about 25 people who did PhDs with me have earned more than I ever did, have had very successful lives, have changed what people do and what they think...and my books too…especially since Ian"

And finally, will there be another Science of Discworld book? "Wait and see if it comes off " (JC). Confided IS (July 5)"There is a good chance there will be another book along the same lines. So far - tentatively - it will be called the Magic of Roundworld and will involve the witches and Death. Confirmation in a couple of months" Watch this space!