Nima Arkani-Hamed, a theoretical physicist born in Houston to Iranian parents and now based at Princeton’s Institute for Advanced Study, was trying to name a new concept when he met the novelist Ian McEwan in London’s Science Museum. McEwan suggested ‘the aleph’; Arkani-Hamed instead went for ‘amplituhedron’. That ungainly mouthful serves as the climax to Graham Farmelo’s rich survey of the growing connections between pure mathematics and fundamental physics. Farmelo is himself a physicist, with a particular interest in the subject’s aesthetic dimension. He weighs up the claim, often made, that good physics has to be beautiful and that if it’s beautiful it has to be true. What does that have to do with the ampli-whatsit? We’ll come to that.