Searching for the fundamental laws of the universe, physicists have found themselves developing ambitious mathematical ideas. But without observation and experiment as their guide, are they now doing ‘fairy-tale physics’ as their detractors claim? In The Universe Speaks in Numbers, Graham Farmelo argues that today’s greatest scientific minds are working in a tradition that dates back to Newton. He takes us on an adventure, from the Enlightenment to the breakthroughs of Einstein and Dirac, to the work of modern physicists and mathematicians shedding light on each other’s disciplines, to their mutual surprise and excitement. This blossoming relationship is responsible for huge advances in our understanding of space and time – and as Farmelo explains, could redefine reality as we know it.