The acclaimed Science of Discworld centred around an original Pratchett story about the Wizards of Discworld. In it they accidentally witnessed the creation and evolution of our universe, a plot which was interleaved with a Cohen & Stewart non-fiction narrative about Big Science. In The Science of Discworld II our authors join forces again to see just what happens when the wizards meddle with history in a battle against the elves for the future of humanity on Earth. London is replaced by a dozy Neanderthal village. The Renaissance is given a push. The role of fat women in art is developed. And one very famous playwright gets born and writes The Play. Weaving together a fast-paced Discworld novelette with cutting-edge scientific commentary on the evolution and development of the human mind, culture, language, art, and science, this is a book in which 'the hard science is as gripping as the fiction'. ( The Times )

Roundworld is in trouble again, and this time it looks fatal. Having created it in the first place, the wizards of Unseen Univeristy feel vaguely responsible for its safety. They know the creatures who lived there escaped the impending Big Freeze by inventing the space elevator - they even intervened to rid the planet of a plague of elves, who attempted to divert humanity onto a different time track. But now it's all gone wrong - Victorian England has stagnated and the pace of progress would embarrass a limping snail. Unless something drastic is done, there won't be time for anyone to invent spaceflight and the human race will be turned into ice-pops.

Why, though, did history come adrift? Was it Sir Arthur Nightingale's dismal book about natural selection? Or was it the devastating response by an obscure country vicar called Charles Darwin, whose bestselling Theology of Species made it impossible to refute the divine design of living creatures? Either way, it's no easy task to change history, as the wizards discover to their cost. Can the God of Evolution come to humanity's aid and ensure Darwin writes a very different book? And who stopped him writing it in the first place?

The fourth book in the Science of Discworld series, and this time around dealing with THE REALLY BIG QUESTIONS, Terry Pratchett’s brilliant new Discworld story Judgement Day is annotated with very big footnotes (the interleaving chapters) by mathematician Ian Stewart and biologist Jack Cohen, to bring you a mind-mangling combination of fiction, cutting-edge science and philosophy.

Marjorie Daw is a librarian, and takes her job – and indeed the truth of words – very seriously. She doesn’t know it, but her world and ours – Roundworld – is in big trouble. On Discworld, a colossal row is brewing…

The Wizards of Unseen University feel responsible for Roundworld (as one would for a pet gerbil). After all, they brought it into existence by bungling an experiment in Quantum ThaumoDynamics. But legal action is being brought against them by Omnians, who say that the Wizards’ god-like actions make a mockery of their noble religion.

As the finest legal brains in Discworld (a zombie and a priest) gird their loins to do battle – and when the Great Big Thing in the High Energy Magic Laboratory is switched on – Marjorie Daw finds herself thrown across the multiverse and right in the middle of the whole explosive affair.

As God, the Universe and, frankly, Everything Else is investigated by the trio, you can expect world-bearing elephants, quantum gravity in the Escher-verse, evolutionary design, eternal inflation, dark matter, disbelief systems – and an in-depth study of how to invent a better mousetrap.

The fantastic first book in the Sunday Times bestselling Science of Discworld series

When a wizardly experiment goes adrift, the wizards of Unseen University find themselves with a pocket universe on their hands: Roundworld, where neither magic nor common sense seems to stand a chance against logic.

The Universe, of course, is our own. And Roundworld is Earth. As the wizards watch their accidental creation grow, we follow the story of our universe from the primal singularity of the Big Bang to the internet and beyond.

Through this original Terry Pratchett story (with intervening chapters from Cohen and Stewart) we discover how puny and insignificant individual lives are against a cosmic backdrop of creation and disaster. Yet, paradoxically, we see how the richness of a universe based on rules, has led to a complex world and at least one species that tried to get a grip of what was going on.

Terry Pratchett is the acclaimed creator of the global bestselling Discworld series, the first of which, The Colour of Magic , was published in 1983. Raising Steam is his fortieth Discworld novel. His books have been widely adapted for stage and screen, and he is the winner of multiple prizes, including the Carnegie Medal, as well as being awarded a knighthood for services to literature. After falling out with his keyboard he now talks to his computer. Occasionally, these days, it answers back.

www.terrypratchett.co.uk
@terryandrob

Professor Ian Stewart is the author of many popular science books. He is the mathematics consultant for New Scientist and a Professor of Mathematics at the University of Warwick. He was awarded the Michael Faraday Prize for furthering the public understanding of science, and in 2001 became a Fellow of the Royal Society.

Dr Jack Cohen is an internationally-known reproductive biologist, and lives in Newent, Gloucestershire. Jack has a laboratory in his kitchen, helps couples get pregnant by referring them to colleagues, invents biologically realistic aliens for science fiction writers and, in his spare time, throws boomerangs. Jack, who has more letters to his name than can be repeated here, writes, lectures, talks and campaigns to promote public awareness of science, particularly biology. He is mostly retired.