Delight of Thinking

Paul Ehrenfest grew up in a middle-class Jewish family in Vienna. Tatiana Afanassjewa came from a wealthy family in St Petersburg. Their love of science brought them together at the beginning of the twentieth century and led them to Leiden in the Netherlands. There, the ebullient Ehrenfest built up an enormous international network of mostly physicists. Afanassjewa worked -- inevitably -- mainly a...