Southampton Row, in London's Bloomsbury district, has been witness to some transformative moments over the years. The most staggering occurred on 12 September 1933, when the idea of a nuclear chain reaction occurred to the Hungarian physicist Leo Szilard as he crossed that very road. His thinking led to the development of the atom bomb. The moment is best captured in the words of US historian Richard Rhodes, who wrote that, 'as he crossed the street time cracked open before him and he saw the way to the future, death into the world and all our woes, the shape of things to come'.