This is the first full-length biography of Ernest Rutherford (1871-1937), the most important experimental physicist of his time, and probably the most ingenious since Faraday. It was Rutherford who discovered the atomic nucleus and who first split an atom.Based in large part on previously inaccessible letters and other papers, the book traces Rutherford's life from his upbringing in the pioneering society of New Zealand to his burial in Westminster Abbey as Lord Rutherford of Nelson. It recounts his student years at Cambridge, working with J.J. Thomson on the newly discovered X-rays; the years of McGill University when (with Soddy) he established the laws of radioactive decay and demonstrated the transmutation of elements, work that resulted in a Nobel prize; his highly productive years at Manchester when he discovered the nucleus and developed in collaboration with Niels Bohr, the standard model of atomic structure; and finally, his return to Cambridge to direct the Cavendish Laboratory.Wilson unearths new material on Rutherford's development of SONAR-like antisubmarine devices during World War I, an official secret for many years after his death. He also presents new information on Rutherford's relationship to Russian physicist Peter Kapitza, his favourite son, who was denied permission to return to Cambridge after a visit to his homeland in 1934. The Kapitza affair unleashed a storm of protest in international scientific and political circles. The book also offers numerous personal glimpses of Rutherford - the hundreds of unreported experimental dead ends that lay behind his legendary scientific intuition, and the sensitive and sympathetic side of the older Rutherford who presented a gruff, crusty exterior to his colleagues.