Item 30-31 - Copies of letters between J. R. G. Bradfield and C. R. Peter and a memorial address by Sir A. B. Pippard about O. R. Frisch

Otto Robert Frisch was born 1 October 1904 in Vienna to Justinian and Auguste (née Meitner) Frisch. Justinian was a printer with a talent for painting, Auguste was a pianist whose sister Lise Meitner was a respected physicist. The family was large and close-knit and of Jewish heritage and the events of the Thirties and the Second World War meant many family members were forced to rebuild lives and careers on foreign soil. Frisch's father was briefly interned in Dachau before being released to work in Sweden.

Otto displayed an early talent for mathematics that evolved into an interest in physics, encouraged in part by his aunt. At the University of Vienna he studied the effects of electrons on salts under Karl Przibram, and obtained a DPhil in 1926. He then took a job in industry, working for an inventor whose firm supplied X-ray dosimeters, and after a year of this he was given a job in Berlin in the optics division of the Physikalisch Technische Reischsanstalt, where he worked from 1927 to 1930.

Frisch then moved on to Hamburg, where he worked with Otto Stern, well-known for his Stern-Gerlach experiment. Here he assisted Stern’s work on molecular beams and the diffraction of atoms by crystal surfaces. His Jewish heritage, however, meant that he was no longer able to work once the racial laws were passed in Germany in 1933. Stern found him a job for a year at Patrick Blackett’s laboratory at Birkbeck College, London, where he worked on artificial radioactivity, and while there he was invited by Niels Bohr to go to work at the Institute of Theoretical Physics in Copenhagen.

At the Institute Frisch worked on neutron physics, and while visiting his aunt in Stockholm over Christmas 1938 they studied Otto Hahn and Fritz Strassman’s results of an experiment on neutron collision. Together they wrote a paper providing an explanation of the collision, with a corroborative experiment and suggested a name for the process: nuclear fission. In 1939, seeing that it was a matter of time before Denmark fell to the Germans, he accepted an invitation to become a lecturer at the University of Birmingham. While there he researched and wrote the important ‘Frisch-Peierls memorandum’, 'On the construction of a "super-bomb" based on a nuclear chain reaction in uranium', having realized that it would be possible to create a powerful explosion using a portable amount of uranium-235. At this, he was invited to work on the Maud Committee, and moved to Liverpool to work with James Chadwick on the ‘Tube Alloys’ programme. In 1943, after being naturalized as a British citizen, he moved with other British scientists to Los Alamos to work on the Manhattan Project, where he was head of the Critical Assembly Group and an eyewitness of the Trinity Test of an atomic bomb in July 1945.

After the war, Frisch spent a year and a half as head of the nuclear physics division of the Atomic Energy Research Establishment at Harwell before was offered the Jacksonian Chair of Natural Philosophy at Cambridge. In 1948 he became a Fellow of Trinity College. He married Ursula (Ulla) Blau in 1951, and they had two children. He became head of the Cavendish Laboratory in 1954. An abiding interest in instrumentation resulted in his invention of and investment in SWEEPNIK, a semi-automatic measuring machine designed for bubble chamber photographs. In 1969, he established Laser Scan Limited, the first company to take premises in Cambridge Science Park.

Frisch, who was known as Otto or Robert at different times in his life, played several musical instruments, chiefly the piano, on which he was proficient to recital standard. In later life he gave increasing time to music, regularly attending the Dartington School, and sometimes giving lectures there. He was an accomplished caricaturist as well. He spoke German, Danish, and English fluently, lecturing in German and Danish to the end of his life, but preferring to write in English. An ardent believer in the value of explaining science to the general public, he not only wrote books and articles on the subject, but appeared on many radio and television broadcasts over the years. He died in 1979 shortly after completing his autobiography, What little I remember.