Andrew Brown wrote the first biography of Sir James Chadwick (1891–1974), Nobel laureate and discoverer of the neutron. Research for this led him to interview Professor Sir Joseph Rotblat, whose biography he is well placed to write. It is based largely on material appearing in Rotblat's Churchill College Archive, some four tonnes of papers having been removed from his house after his death in 2005.
Rotblat was born in Warsaw in 1908, in what was a prosperous household, but suffered severe poverty after the failure of the family business at the start of the First World War. He started work as a domestic electrician with a growing ambition to become a physicist. Without formal education he won a place in the physics department of the Free University of Poland, gaining an MA in 1932, and then a doctorate in physics at the University of Warsaw in 1938. During his time in Warsaw he made major discoveries, including inelastic neutron scattering and Cobalt-60, subsequently used worldwide in radiotherapy. With the discovery of nuclear fission, he repeated the experiments and showed that in the fission process more neutrons were emitted than absorbed; he was probably ahead of Joliet-Curie, who won the Nobel Prize for this discovery.
In early 1939 Rotblat envisaged that a large number of fissions could occur, and if they did so in a short enough period of time, then considerable amounts of energy could be released. The idea of an atomic bomb occurred to him around February 1939. In the same year he was invited to study under James Chadwick, then at Liverpool University, who was building a cyclotron to study fundamental nuclear reactions. After the outbreak of war Chadwick instructed Rotblat to investigate the properties of uranium, to determine the absorption cross-section for fast neutrons and the energy spectrum of fission neutrons. Following work by Otto Frisch and Rudolf Peierls, it became clear that it was only a matter of time before a bomb could be made.
In 1944 Rotblat joined Chadwick's group working on the Manhattan Project, but walked out in under a year. His ambivalence towards the project was compounded when, at a dinner hosted by Chadwick, General Groves announced to the room that the whole purpose of the bomb was to subdue the Russians, a statement that appalled Rotblat as they were an ally. Some did not believe his account, and Brown discusses whether Groves would ever have made such a comment with Rotblat present. It has also been questioned whether Rotblat's memory is accurate. Rotblat's concerns were further compounded by his being considered a security risk, if not a Soviet spy.
Rotblat was shocked and appalled when the bomb was used over Hiroshima and Nagasaki, and on returning to Liverpool his research interests moved towards the medical applications of nuclear science. He took up the post of professor of physics as applied to medicine at St Bartholomew's Medical College, London University, in 1950. Rotblat made important contributions to understanding the effects of fallout from nuclear bomb tests and, together with Professor Patricia Lindop, did fundamental work on the biological effects of radiation. He oversaw the installation of a 15 MeV linear accelerator dedicated solely to research.
Rotblat took the lead in setting up the Atomic Scientists Association to stimulate public debate on the peaceful uses of nuclear science; this adopted a non-political agenda but was wound down in 1959. Rotblat also collaborated with Bertrand Russell and helped launch the ‘Russell–Einstein Manifesto’ in 1955, calling for a conference of scientists to discuss nuclear disarmament and the abolition of war. This led to the foundation of the Pugwash Conferences on Science and World Affairs, the key founding principle of which was that participants attended as individuals and not as government representatives. Rotblat was secretary general of Pugwash from 1957 to 1993, when it was instrumental in achieving agreement on the 1963 Partial Test Ban Treaty; helped to establish links between the US and Vietnam in the late 1960s; and played a role in the renegotiation of the 1972 Biological Weapons Convention. He was chairman of British Pugwash from 1980 to 1988, and president from 1998 to 1997. In 1995 Rotblat was finally elected FRS for his brilliance as an experimental physicist, and also that year, together with Pugwash, was awarded the Nobel Prize for Peace; he was knighted in 1998.
Rotblat said of his working life that it comprised twenty years of nuclear physics, thirty years of medical physics, and fifty years of Pugwash. Brown is an adviser to the Centre of Arms Control and Proliferation in Washington, and is clearly enamoured of Rotblat and his achievements in this field. Roughly two-thirds of the text are concerned with Rotblat's development as a public figure involved in peace-related activities. The author presents an account of Rotblat's early life and crucial work in neutron physics and achievements in medical physics, but perhaps a more extensive exposition of his successes in these areas was required.
Some other interesting aspects of Rotblat's life and career are not adequately addressed in this volume. Rotblat made it very clear in his 1985 paper ‘Leaving the bomb’ that when he departed from Los Alamos all of his papers were packed into a trunk which disappeared on the train journey to Washington, where the Chadwicks had located, never to be seen again. Rotblat believed for the rest of his life that the trunk was appropriated by US security officials. However, there is a body of papers in the Churchill Archive from his time at Los Alamos, which is not mentioned by Brown. In addition, the 15 MeV accelerator that Rotblat installed at St Bartolemew's never performed to specification and suffered regular breakdown. Norman Kember, who succeeded Rotblat as head of the academic department, noted that only one publication was produced during the lifetime of the machine and remarked that ‘great men are allowed to make great mistakes’.
Some did think of Rotblat as arrogant, and he was certainly a showman. He was, however, a towering intellectual figure whose contributions to mankind should be better known and more widely understood. Andrew Brown's fine book goes some way in achieving that end.
