196 Nature Vol. 284 13 March 1980 OBITUARY O.R. Frisch, 1904-1979 ON 22 September 1979 Professor Otto Bohr's Institute were very fruitful. It was Robert Frisch, OBE, FRS, Emeritus the time when neutron physics had been Jacksonian Professor in the University of initiated by Fermi's work, and Frisch, too, Cambridge, died following an accident. He started on neutron work. Probably he was was a distinguished and original nuclear drawn in initially because he happened to physicist. His contributions to physics will have the most appropriate counter with be, and the example he set in his approach which to test for neutron-induced activity. to the subject should be, remembered by He made many important contributions to future physicists. that subject. Both in physics and in music, which was It was in neutron physics that he did his next to physics his strongest interest, his most famous piece of work. He was main driving force was enjoyment of what spending Christmas 1938 with Lise he was doing. In physics this meant using Meitner, who was now in Sweden. She simple apparatus, preferably designed and received a letter from Otto Hahn, with made by himself, and looking for whom she had collaborated closely until important problems with transparent she had to leave Germany, telling her of his answers. Some of the instruments he made discovery that barium was among the might be called gadgets, but surprisingly products emitted when uranium was bom­ often these gadgets were able to provide barded with neutrons. Hahn realised this answers to topical problems. Naturally meant that the uranium nucleus must have ''big physics'' was not his line, and he never split into two large pieces. Frisch and Lise became involved with projects needing Meitner were as dumbfounded by this news large machines and large teams of as all other physicists when they heard of it. collaborators. But after thinking about the discovery for a His piano playing was of near­ while, they understood how the strong professional standard, but he was not a ideas of my own''. His assignment was electric charge could help to overcome the perfectionist, and was not above listening hardly exciting, but he was able to attend suface tension and lead to an unstable to, or playing with, musicians of a much seminar meetings at the university, and configuration once the nucleus was set lower calibre, provided they shared his listen to remarks by Einstein, Planck, vibrating by a collision. If the nucleus had enjoyment of the result. Nernst and others. Lise Meitner was there, taken a sufficiently elongated form the He was born on 1 October 1904 in too. She worked, and lived, in the suburb mutual repulsion of the positive charges Vienna. His father, Justinian Frisch, was a of Dahlem, but Frisch saw her frequently, would drive it apart, and this would release printer, his mother a very gifted musician. I to the profit of his physics and his music. an energy of about 200 MeV. Frisch coined do not know whether his father's In 1930 he became an assistant to Otto the word "fission" for this process. After profession int1uenced his interest in writing Stern in Hamburg, famous for the Stern­ returning to Copenhagen and composing a and his t1air for the written word, but no Gerlach experiment. Stern was an out­ letter to Nature jointly with Lise Meitner doubt his mother encouraged his music. standing experimenter, not in manual skill, over the telephone to Stockholm, he The members of the family were very close, but in his command of the relevant carried out an impressively simple and all his life he remained in touch with his principles and in the design of experiments, experiment proving the emission of relatives. Above all he was very close to his and his laboratory was the leading one in energetic and heavily ionizing particles aunt, Lise Meitner, the famous nuclear the world for atomic-beam research. Frisch from the bombarded uranium, and thus physicist. worked closely with him and took part in confirmed the interpretation. At school Otto Robert (as he was known important experiments, including the first Fission was now the exciting part of to the family; later he was just Robert to his observation of the diffraction of atomic nuclear physics, and most nuclear physics friends, except for the Los Alamos period, beams by crystal surfaces. At the end of his laboratories started to work on this. Frisch when there were too many Roberts around, Hamburg period he did his first important continued in this field, too, and did several and he became Otto) showed marked experiment on his own, observing the recoil more important experiments. ability in mathematics, and almost chose it of atoms on photon emission. But this was 1939. War was imminent, as a career, but in the end decided that this But by this time the Nazi government and Denmark not too healthy a place for a would be too abstract for his taste, and he was in power, and both Stern and Frisch, German refugee. (The Anschluss had made settled for physics. who were of Jewish descent, had to leave. him a German subject). Besides, the His studies in the University of Vienna Frisch went to Birkbeck College to work Danish police were making difficulties under Professor Karl Przibram appear to under Blackett with a grant from the about extending his permit. So he tried to have been uneventful, and he obtained his Academic Assistance Council. Here he find a place in England, and, when D Phil in 1926, after four years in the became interested in nuclear physics, Oliphant heard of his problem, he university. This was rapid progress, but at which in 1933 was full of excitement. He arranged an appointment for him in the the time not unusual. After a year in a small invented a method of measuring very University of Birmingham. Here Oliphant firm run by an inventor, where he short-lived activities, and this led to the was trying to build up facilities for nuclear presumably could indulge in his love for discovery of some new radioactive iso­ physics work, but there was not much gadgets, he accepted a post in the topes. equipment as yet, and Frisch could not Physikalisch-Technische Reichsanstalt in A year later, Niels Bohr, who must have continue his experimental work Berlin. His work there was in the optics heard of his ingenuity in devising and immediately. But he continued speculating division, with the assignment to work on a carrying out experiments, invited him to about fission. proposed new light standard, but he says "I Copenhagen. The next five years in the The possibility of the release of nuclear stayed long hours trying out half-baked informal and stimulating atmosphere of energy was then in many people's minds,

© 1980 Nature Publishing Group Nature Vol. 284 13 March 1980 197 once it had been shown that neutrons were tration was not his favourite pastime, but Mediterranean atmosphere with the colour emitted after the fission. One was awed by he found that his deputy Dr (later Sir) play and diverse insect cacophony in the the thought of a new weapon of terrifying Robert Cockburn delighted in running flower fields he developed a love and power, but Frisch, like others who had things and did it well. Frisch left Harwell in interest of plants and animals. In Basel in understood the paper by Bohr and Wheeler 1947 to become the Jacksonian Professor 1944 he was awarded a PhD in zoology. on the mechanism of fission, and Bohr's of Physics in Cambridge and a Fellow of After his marriage to Noemi Stoecklin, argument that the fission caused by slow Trinity. At that time nuclear physics in daughter of the Basle artist Niklaus neutrons was due to the rare isotope 235 U, Cambridge was overshadowed by Stoecklin, which proved to be a true life were reassured that no violent explosion cystallography and other lines. It was not in partnership, he began, with her, his life­ could happen in ordinary uranium. The Frisch's character to fight for more long progress as a zoologist. They shared a thought of separating uranium isotopes in support. Besides, nuclear physics had now life of work, pleasures and trials. A great large quantities seemed to belong to science become big physics and less to his taste. deal of his professional success was due to fiction. Then one day Frisch came to me While he kept a lively interest in nuclear his close accord with his wife, with guests and said ''Suppose one had a large amount physics and in the newly developing always welcome at their home. of separated 235 U, what would happen?" particle physics, he spent more of his time As a young zoologist, LUscher 's first One could make a guess at the fission cross teaching and writing. Many students post was as a research assistant in Berne, section from the ideas of Bohr, and I knew profited from contact with his way of doing where he worked under F.E. Lehmann on how to estimate the critical size, given the and looking at things. He still liked the physiology of development of cross section. The answer staggered us by gadgets, and made many ingenious instru­ amphibians. Soon afterwards he met his being smaller than we would have guessed. ments. His writing included Meet the great teacher, the insect physiologist, Sir Next we had to estimate how far the chain Atoms, a very readable popular intro­ Vincent Wigglesworth of Cambridge, reaction would proceed before the energy it duction to modern physics. Only a few under whom he was able to work. Martin released would drive the uranium apart. months ago he published his recollections LUscher saw Wigglesworth as the founder The answer again staggered us by being a under the appealing title What little I of a new branch of research: experimental reasonable fraction of the total energy remember, 1 and it is pleasing that he was insect physiology. available. If that was so, we said, it would able to leave this lively record of his From England LUscher moved to Paris, be, as a weapon, worth its price, even if the personality. where he was introduced to the biology of isotope separation plant cost as much as a Shortly after moving to Cambridge he termites by the renowned termite specialist battleship (this turned out to be an under­ married, and there were two children. His T.P. Grasse and found the stimulus for estimate). What if the Germans got there wife shared not only his Austrian origin, what was to become his principal research first and a nuclear bomb was in the hands but very many of his attitudes and his love -caste formation in termite colonies. He of Hitler's Germany? for music. wished to study termites in the field as well We wrote down our arguments, and that Shortly before retiring in 1972 he as the laboratory, and he soon had the was the start of serious interest in atomic invented an apparatus for measuring and opportunity to take part in an expedition to energy work in England. Frisch first tried evaluating bubble-chamber tracks, and he observe at first hand the highly organised to explore the possibility of isotope later became a partner in a firm set up to termite colonies of Africa. LUscher was separation by thermal diffusion, but did manufacture this. I do not know whether particularly fascinated by the highly not get far, and we now know that the this commercial activity made him a elaborate nest structures built by the thermal diffusion coefficient in the only wealthy man, but he clearly enjoyed this millions of termites within the colony. He gaseous uranium compound happens to be novel position and seeing his gadget being was the first to understand their design as a practically zero. Instead Frisch moved to produced. well planned respiratory system with Liverpool, where in Chadwick's His was a full life, but he just failed to temperature and humidity regulation, and laboratory there was a cyclotron and other reach his seventy-fifth birthday with its an air circulation system functioning facilities for nuclear physics, and worked warm messages from his many friends. through the warming of the air inside the on the nuclear physics aspects of atomic RudolfPeierls nest. After imaginative and productive energy until the end of 1943, when it was I. Frisch, O.R. What Lirr/e I Remember. (Cambridge University field work he spent a very important year of decided to discontinue work in England Press, 1979) See review by Rudolf Peierls in Nature 280, 257·259 study in the United States on a grant from (19 July 1979). and move to America those who could be the Rockefeller Foundation. He was given useful to the American work. the opportunity to stay for some time with So Frisch went to Los Alamos, the A.E. Emerson, the expert on termite strange atom-bomb city in the middle of biology and taxonomy, and was then able New Mexico. He was not attached to any to acquaint himself with modern methods specialist team but had a roving assignment of insect endocrinology in the leading and in that way was able to give essential laboratories at Berkeley, and at Harvard help to many different groups. One of the Martin Luscher with C.M . Williams. Afterwards he experiments he set up himself was a worked at the Swiss Tropical Institute in typically original scheme known as the IN THE midst of his fruitful work, Martin Basel and in 1954 was appointed professor dragon. Two pieces of fissile material LUscher's life was taken on 9 August 1979 at the University of Berne. Under his which together would make a critical mass by a tragic accident, at the age of 63. He direction the new Department of Zoo­ and so cause a violent chain reaction, were was Professor of Zoology at the University physiology was formed. allowed near each other for only a short of Berne, and directed its Department of In 1965 he was appointed to the four­ moment, by dropping one piece past the Zoophysiology with scientific foresight year directorship of the Zoological other. The speed was so arranged that the and a fatherly concern for his colleagues Institute. During the academic year chain reaction did not develop to any and students . His name will be 1967/ 68 he was Dean of the natural science dangerous degree. The name indicated that remembered by zoologists throughout the faculty and from 1969 a member of the one was tickling the tail of a dragon. The world. Swiss National Science Foundation. In his experiment made it possible to observe Martin LUscher, son of the Basle artist last important undertaking, in Nairobi as details of a near-critical situation which Jean-Jacques LUscher, spent a quiet youth project leader at the newly founded were otherwise hard to get at. in his family home, with extended visits to International Centre of Insect Physiology After the war, Frisch returned to Provence. There, the harmony and beauty and Ecology, he set up an enthusiastic England and became head of the Nuclear of the landscape created a lasting research team. Physics Division at Harwell. Adminis- impression on him; in the balmy Li.ischer carried his title with quiet

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