A revised and updated edition of this bestselling title, containing two new chapters and a new jacket.

In the 'fantasy' universe of the phenomenally bestselling Discworld series, everything runs on magic and common sense. The world is flat and million-to-one chances happen nine times out of ten. Our world seems different - it runs on rules, often rather strange ones. Science is our way of finding out what those rules are. The appeal of Discworld is that it mostly makes sense, in a way that particle physics does not. The Science of Discworld uses the magic of Discworld to illuminate the scientific rules that govern our world.

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.