German-language version of Pyramids. Works Discworld Pratchett began writing the Discworld series in 1983 to "have fun with some of the cliches" and it is a humorous and often satirical sequence of stories set in the colourful fantasy Discworld universe. The series contains various story arcs (or sub-series), and a number of free-standing stories. All are set in an abundance of locations in the same detailed and unified world, such as the Unseen University and 'The Drum/Broken Drum/Mended Drum' public house in the twin city Ankh-Morpork, or places in the various continents, regions and countries on the Disc. Characters and locations reappear throughout the series, variously taking major and minor roles. The Discworld is a large disc resting on the backs of four giant elephants, all supported by the giant turtle Great A'Tuin as it swims its way through space. The books are essentially in chronological order, and advancements can be seen in the development of the Discworld civilisations, such as the creation of paper money in Ankh-Morpork. Many of the novels in Pratchett's Discworld series parody real-world subjects such as film making, newspaper publishing, rock and roll music, religion, philosophy, Ancient Greece, Egyptian history, the Gulf War, Australia, university politics, trade unions, and the financial world. Pratchett also included further parody as a feature within the stories, including such subjects as Ingmar Bergman films, numerous fiction, science fiction, and fantasy characters, and various bureaucratic and ruling systems. The Science of Discworld Pratchett wrote four Science of Discworld books in collaboration with Professor of mathematics Ian Stewart and reproductive biologist Jack Cohen, both of the University of Warwick: The Science of Discworld (1999), The Science of Discworld II: The Globe (2002), The Science of Discworld III: Darwin's Watch (2005), and The Science of Discworld IV: Judgement Day (2013). All four books have chapters that alternate between fiction and non-fiction: the fictional chapters are set within the Discworld universe, where characters observe, and experiment on, a universe with the same physics as ours. The non-fiction chapters (written by Stewart and Cohen) explain the science behind the fictional events. In 1999, Pratchett appointed both Cohen and Stewart as "Honorary Wizards of the Unseen University" at the same ceremony at which the University of Warwick awarded him an honorary degree. Folklore of Discworld Pratchett collaborated with the folklorist Dr Jacqueline Simpson on The Folklore of Discworld (2008), a study of the relationship between