Stefan Buijsman was born in 1995 and gained a master’s degree in philosophy in Leiden at the age of eighteen, after which he moved from Sweden to work on a PhD. Within eighteen months (instead of the usual four years) he gained his doctorate, making him one of the youngest ever PhDs. He is currently studying the philosophy of mathematics as a post-doctoral researcher. Along with Govrien Oldenburger he is the author of a children’s book The Kingdom of Sums (2018). He lives in Amsterdam.

Andy Brown is an English translator and editor who has been living in the Netherlands for 35 years. He has translated around 20 books of non-fiction, specialising in popular science.