Carlo Rovelli, an Italian physicist, emeritus professor at the Centre de Physique Théorique in Marseille, has in the last 15 years or so established himself as a leading populariser of science. Although his specialist field, quantum gravity, is one of the most inaccessible areas of contemporary thought, he has reached an astonishingly wide audience through his public lectures, YouTube videos and popular books, several of which have become bestsellers.