CHARLES A. BARNES (b. 1921) INTERVIEWED BY HEIDI ASPATURIAN July and August 1987 Charles A. Barnes, 1979 ARCHIVES CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California Subject area Physics Abstract Interview in six sessions, July and August 1987, with Charles A. Barnes, professor of physics, Caltech. He talks about his childhood and adolescence in Ontario, Canada; his early affinity for mathematics and science; undergraduate years at Canada’s McMaster University; wartime work in the British-Canadian atomic energy project at Chalk River, Montreal; and postwar PhD studies in physics at the University of Cambridge, working with O. Frisch and D. Wilkinson. The discussion of his 40-year career in Caltech's Kellogg Radiation Laboratory deals with many aspects of the lab’s history, personnel, and research contributions. Barnes talks about his nuclear physics collaborations with W. Fowler, T. Lauritsen, C. Lauritsen, and R. Christy. He gives a detailed account of his and Kellogg’s accelerator-based investigations into the nature of the weak nuclear interaction—a key focus of postwar work in quantum field theory and the development of grand unified theories—and describes research collaborations in this area with theorists M. Gell-Mann and R. P. Feynman. He talks about http://resolver.caltech.edu/CaltechOH:OH_Barnes_C Kellogg’s social and scientific culture, the development of its accelerators and the chronology of its research, its groundbreaking investigations into stellar evolution and stellar nucleosynthesis, and the awarding of the 1983 Nobel Prize in physics to Fowler for his work in nucleosynthesis. Barnes describes his work with J. Bahcall on the solar neutrino flux and discusses the research contributions of K. Thorne, J. DuMond, F. Boehm, M. Schmidt, and G. J. Wasserburg, among others. The interview also covers Kellogg’s role in the physics and astrophysics community, both within and beyond Caltech, and the lab’s relationship with Caltech administration, including presidents and division chairs; Barnes’s work with students; and his views on current trends and future directions in physics and astrophysics. Administrative information Access The interview is unrestricted. Copyright Copyright has been assigned to the California Institute of Technology © 2012. All requests for permission to publish or quote from the transcript must be submitted in writing to the Head, Archives and Special Collections. Preferred citation Barnes, Charles A. Interview by Heidi Aspaturian. Pasadena, California, July and August, 1987. Oral History Project, California Institute of Technology Archives. Retrieved [supply date of retrieval] from the World Wide Web: http://resolver.caltech.edu/CaltechOH:OH_Barnes_C Contact information Archives, California Institute of Technology Mail Code 015A-74 Pasadena, CA 91125 Phone: (626)395-2704 Fax: (626)395-4073 Email: [email protected] Graphics and content © 2012 California Institute of Technology. http://resolver.caltech.edu/CaltechOH:OH_Barnes_C Charles A. Barnes, 1979 http://resolver.caltech.edu/CaltechOH:OH_Barnes_C CHARLES BARNES IN 1969. Caltech Archives WILLIAM FOWLER AND CHARLES BARNES IN 1982, INSPECTING KELLOGG LABORATORY’S THEN NEWEST TANDEM ACCELERATOR, THE PELETRON—DESIGNED BY BARNES ALONG WITH ENGINEERS FROM THE NATIONAL ELECTROSTATIC CORPORATION. Caltech Archives http://resolver.caltech.edu/CaltechOH:OH_Barnes_C CALIFORNIA INSTITUTE OF TECHNOLOGY ARCHIVES ORAL HISTORY PROJECT INTERVIEW WITH CHARLES A. BARNES BY HEIDI ASPATURIAN PASADENA, CALIFORNIA Copyright © 2012 by the California Institute of Technology http://resolver.caltech.edu/CaltechOH:OH_Barnes_C Barnes–ii TABLE OF CONTENTS INTERVIEW WITH CHARLES A. BARNES Session 1 1-15 Early childhood interest in math and science encouraged by minister father; early years and pre- college educational experiences in Ontario, Canada; influence of reading and schoolteacher mother on intellectual outlook. Undergraduate experience (BS ’43) at McMaster University (Hamilton, Ontario, Canada). Impressions of university’s math and physics program. Wartime environment at McMaster, including student military training, impact of deaths of enlisted classmates, and summer work as student instructor in RAF radar engineering program. Awareness of nuclear fission research in early 1940s. Canadian mobilization for war effort; POW camps in Ontario. Session 2 16-32 Begins MS program in 1943 at University of Toronto under geophysics adviser: geophysics fieldwork on Cheddar Batholith; magnometer research in Canadian forests. Participates in British-Canadian Atomic Energy Project at Chalk River, Montreal. Recollections of Italian physicist and alleged Communist spy Bruno Pontecorvo: politics, wartime activities, physics contributions. Research at Fall River; visits by N. Bohr and General L. Groves; facility’s rather lax security provisions. First contact with R. Bacher over prospect of pursuing PhD work at Cornell. Accepts scholarship to study at University of Cambridge. Travels to UK on one of the first postwar Atlantic crossings; shipboard experiences and recollections of fellow passengers. Physics PhD work with adviser O. Frisch and D. Wilkinson. Fritsch’s personality; Frisch-Meitner fission experiment (1939); Meitner visits Cambridge. Academic environment at Cambridge; interactions with fellow students. Session 3 33-66 Differences between British and American approaches to graduate education; vacation breaks on European continent; marriage in England. PhD research on measuring the cross section for photo-disintegration of the deuteron: development of experimental detector and development of technique for measuring radiation. Investigation of angular correlation between alpha and gamma emission: Discussions with Cambridge professor S. Devons; encounters research by C. and T. Lauritsen and W. Fowler; carries out first-ever successful measurement of alpha-gamma correlation; meets T. Lauristen. http://resolver.caltech.edu/CaltechOH:OH_Barnes_C Barnes–iii Faculty experiences at University of British Columbia (1951–1953): environment, responsibilities, and faculty/student challenges in development of UCB’s new PhD program. Visit by physicist R. Herb, “father” of the Van de Graaff accelerator. Barnes unexpectedly “hosts” first large American Physical Society party and writes to T. Lauritsen about possibility of coming to Caltech. Relocates to Pasadena in 1953. Begins research work with Kellogg Laboratory electrostatic accelerators. Unexpected discovery of new low-lying states in F-19. Studies Coulomb excitation of these states with W. Fowler, C. Lauritsen, and R. Christy. Receives tenure-track job offers from UCLA and Caltech. Post-war atmosphere and personalities in Kellogg. R. Christy as theorist; his understanding of instrumentation. C. Lauritsen as scientist and Kellogg administrator. Kellogg’s relationship with Physics, Mathematics and Astronomy (PMA) Division; personalities in Kellogg: R. Bacher, R. Walker, A. Tollestrup, M. Sands. Relationship between Kellogg and high-energy physics and astronomy/astrophysics in 1950s. Impact of H. Bethe’s 1930s papers on hydrogen- burning on direction of Kellogg's research. K. Thorne’s early relationship with Kellogg. Barnes’s teaching responsibilities. Research into weak interaction spurred by seminal Yang-Lee paper on non-conservation of parity; 1955 Brookhaven Laboratory (Rustad and Ruby) experiments on beta decay (Tensor vs. Axial Vector); R. Feynman–M. Gell-Mann collaboration on weak interaction. Kellogg Lab investigates beta polarization. Barnes and grad student discover error in original Brookhaven determination of beta decay interaction as tensor; correspondence with C. S. Wu (see also Session 4). Collaboration with F. Boehm to measure the level of polarization of the beta rays from the decay of N-13. Session 4 67-82 Interpersonal friction in Kellogg in the 1950s. J. DuMond’s X-ray research, spectrometer building, and work with F. Boehm. 1960s construction of new synchrotron accelerator lab in Kellogg; overview of accelerators at UC Berkeley. Early synchrotron experiments in Kellogg; Kellogg’s role in fostering Caltech’s high-energy physics program. Students at Caltech contrasted to those at other institutions; Barnes’s enjoyment of teaching. Kellogg investigations of` beta decay of Li-8; determination that decay is via A-V interaction. Influence of Wu letter on Feynman–Gell-Mann work on beta decay (see also Session 3). Feynman’s involvement with Kellogg during beta decay experiments. Feynman and Gell-Mann as scientists and personalities; Feynman’s grasp of experimentation. Recollections of F. Dyson. Session 5 83-130 Speculative implications of parity violation for biology and chemistry. Relationship between theory and experiment in physics; challenges of opening new avenues of investigation in fundamental physics. Kellogg’s decision to branch out into intermediate and high-energy nuclear physics. Growth of “big science” in particle and nuclear physics; its appeal to some scientists. Future of physics as a profession; growing competition with industry for top http://resolver.caltech.edu/CaltechOH:OH_Barnes_C Barnes–iv physicists. Challenges, limitations, and opportunities in development of quantitative nuclear physics theory. Collaboration with Gell-Mann on experiments regarding A-V theory of the weak interaction: isopsin, mirror states in nuclei, weak magnetism, isospin conservation. Weak magnetism experiments comparing beta spectra of B-12 and N-12. Technical aspects of beta spectrometer. Investigation of weak magnetism