Like so many around the world I was greatly saddened by the death of Sir Terry Pratchett earlier this year. Pratchett’s books, especially the discworld series, have been favourites of mine for many years: I would eagerly await the publication of a new title and also find myself returning to old favourites again and again. Many people watch The Sound of Music or It’s a Wonderful Life each Christmas but I would reread Hogfather each year.
Pratchett was not only an immensely prolific author, writing more than 70 novels over the course of a four-decade career, but an incredibly skilled one. He achieved the almost impossible feat of dealing with complex and controversial topics in a way that was accessible, thought provoking and incredibly funny. He was also unfailing moral without being self-righteous, intelligent without being pretentious and astute without being cold. The worlds created in his imagination were wonderful mirrors of our own where I (and so many others) happily got lost countless times. Pratchett’s down-to earth and irreverent sense of humour continued into his later life, when he referred to his Alzheimer’s as “the embuggerance.” I cannot imagine how distressing a neurological condition must have been more someone who relied on their imagination for their living and could create a world behind their eyes that was as rich, varied and bizarre as anything reality could offer.
The topics covered in Pratchett’s work were greatly varied and include religion, gender equality, the movie industry, fairy tales and several Shakespearean works. A fair number of scientific and tech related topics are also referenced; among them cryptography, chaos theory and the many-worlds theory of quantum mechanics. One of my favourites of his treatments of the scientific world is the idea of a new colour (octarine, the colour associated with magic that can only be seen by wizards). The idea of different colours corresponding to different wavelengths is a fairly common topic on most KS3/GCSE physics courses but the way in which our eyes register different colours is slightly more complex, involving specialised cells our eyes which are sensitive to different wavelengths. However, while humans have three types of these cells (that are sensitive to red, blue and green light) some creatures have many more, enabling them to see colours we have no name for and no way of describing or visualising. An excellent summary of this idea may be found here.
Perhaps the most fitting tribute to Pratchett has been the news that his name will be incorporated into unseen scripts used by the software and hardware that make up the internet. The idea that his name will be ever present in the everyday life of so many people seems a richly deserved honour for such a prolific and much loved author. GNU Terry Pratchett!
 Not to mention incredibly fond of footnotes.