Established in 1942, the Manhattan Project brought together an international team of scientists in a top secret quest: beating the Nazis to the atomic bomb. Their 'Little Boy' and 'Fat Man' bombs destroyed Hiroshima and Nagasaki in August 1945. In one terrible swoop humans could now kill potentially millions of fellow humans. It was the dawn of a new age - in war, in politics and, so Jeff Hughes deftly explains, in science.