By day, Jack Cohen was a reproductive scientist, whose main contribution to the field was an explanation of why men produce so many redundant sperm. But he was also a close friend of DDP alumni Terry Pratchett (the pair met at a science-fiction convention when Cohen spilled his pint over the big-hatted fantasy doyen). Cohen worked on four volumes of The Science of Discworld, explaining the rules and truths of our world via the fantasy world created by Pratchett.
Jack Cohen
19 September 1933 – 6 May 2019
Died aged 85 (unique hit)