Obituary of Michael Nieto (1940-2013)

Research Associate, Institute for Theoretical Physics, SUNY at Stony Brook (1966-1968); Visiting Physicist, Niels Bohr Institute, University of Copenhagen (1968-1970); Lecturer, UC Santa Barbara (1970-1); Senior Research Associate, Purdue UNiversity (1971-2); Staff Member, Theoretical Division, Los Alamos National Laboratory (1972-2012) and LANL Fellow, 2003-2013.

On 8 June 2013, in Los Alamos, New Mexico, Michael Martin Nieto completed a life of passionate devotion to physics. As a youngster, this son of an immigrant musician and a homemaker encountered a depiction of atomic structure, and although expected to follow in his father’s footsteps, he immediately fell in love with physics and charted a different course.

Born in Los Angeles, California on March 15, 1940 to parents originally from a remote mountain village in Mexico, Michael completed his undergraduate studies at the University of California - Riverside, then entered Cornell University as a Woodrow Wilson Graduate Fellow (1961), continuing as an NSF Graduate Fellow, and received his Ph.D in physics in 1966. He was a Research Associate of the Institute for Theoretical Physics at the State University of New York at Stony Brook (1966-1968) and a Visiting Physicist in the Niels Bohr Institute at the University of Copenhagen (1968-1970), where he met his future wife, Merete. He was also a lecturer at UC Santa Barbara (1970-1) and a Senior Research Associate at Purdue (1971-2) before joining the Theoretical Division at the Los Alamos National Laboratory as a Staff Member (1972-2012).

Michael became a Fellow of the American Physical Society in 1975. He held a Visiting Erskine Fellowship at the University of Canterbury in New Zealand in 1989, and received an Alexander von Humboldt Senior Research Award in 1994, which he used for visits to (Einstein’s birthplace) \'{U}lm, although he always said that Feynman (whose Messenger lectures he attended at Cornell) was his ‘physics hero’. He was recognized with a Distinguished Alumnus Award from UC RIverside in 1999, and received an Award and two Honorable Mentions from the Gravity Research Foundation for Essays on Gravitation. Michael’s contributions to Los Alamos were recognized in 2003 when he became a Laboratory Fellow. In addition to the honors, these awards assisted Michael in pursuing his goal of reaching all the Earth’s continents; ultimately, only Antarctica eluded him.

Michael recalled that, when he asked Peter Carruthers to be his thesis advisor, ‘Pete decided to chase me off by giving me a problem. When I came back a couple of days later [with a solution], Pete was stuck and I was set.’ The problem involved the generation of coherent states in a forced oscillator. Although it did not become a part of his Ph.D thesis on ‘A Dynamical Study of the Quark-Meson System,’ it marked the beginning of his research and a series of seminal papers on quantum action-angle operators, uncertainty relations, and on coherent states and squeezed states for general potentials. Throughout his career, he maintained an ardent commitment to finding exact solutions of quantum mechanical problems. Among his many other contributions to mathematical physics was his work on supersymmetric quantum mechanics, including his explication of the relation between supersymmetry and the inverse scattering method in quantum mechanics and his work on atomic supersymmetry, which remains (today) one of the very few realized physical applications of supersymmetry in Nature.

Michael worked for over forty years on the limits to photon and graviton masses (with ASG). In its careful and persistent attention to the underlying concepts and assumptions made in deducing these limits, as well as to the diverse observations and experiments on which they are based, Michael’s contribution to the subject typified his oeuvre. For nearly as long, he was a leading figure in the search for possible experimental evidence for quantum gravity, and on the gravitational acceleration of antimatter, including early proposals for experiments with antihydrogen; unfortunately his career ended before he could follow the recent and ongoing ALPHA experiments at CERN on the gravitational acceleration of antihydrogen.

Initially motivated primarily by his interest in geophysical measurements of Newton’s gravitational constant, Michael devoted much of his time in the early 1980s to collaborating on a proposal to build a national underground science facility. It was only because he felt so fervently about the need for such a facility that he took time away from his research to temporarily engage in ‘administration and entrepreneurial stuff.’ Nearly two decades later, his interest in gravitational theory led him to become deeply engaged along with researchers at JPL in efforts to understand the very small, but unambiguously confirmed, anomalous acceleration of the Pioneer 10 and 11 satellites and his last publication (with JDA) also found three additional apparently anomalous effects in solar-system dynamics. These efforts demonstrate that Michael was searching for physics ‘beyond the standard model’ before that term, or even the Standard Model itself, was invented.

Michael’s research papers, and especially his numerous authoritative review articles, reflect his careful attention not only to the latest developments but also to the earliest literature on his diverse research areas. His strong interest in the history of physics is evidenced by the book he wrote on the Titius-Bode law of planetary distances (which was translated and printed in Russian in 1976). He also co-edited proceedings on the foundations of quantum mechanics, underground physics, and the 1984 meeting of the Division of Particles and Fields. The long-lasting value of his own work is reflected in the reprinting and translation of approximately a dozen of his more than 200 papers in refereed journals and conference proceedings. In one of the earliest applications of intensive computing to physics visualization, he collaborated in the production of the movie, ‘Time Evolution of Coherent States for General Potentials’.

Michael’s contributions to physics at Los Alamos included his role in early efforts to strengthen theoretical particle physics there; he liked to joke that he hired Carruthers as leader of the Theoretical Division in 1972. His broad enthusiasm for physics, his scholarship and depth also attracted a number of postdocs to T-Division, several of whom (including TG) stayed on at the Laboratory in permanent positions. Throughout the Laboratory, Michael was known as the ‘go to’ guy for questions involving special functions, difficult integrals and quantum mechanics, especially as the last referred to coherent and squeezed states or number-phase relations. He was clearly pleased to be known as the Lab’s ‘quantum mechanic’.

Michael was never one to bow to authority, however established. For many years, his office door had a sheet of paper with a US 5 cent piece taped on it, representing the winnings of a 5 cent wager with a (very prominent) physicist, on the outcome of an experiment. His comment on the episode captures both his feisty but modest character and simultaneous commitment to getting physics exactly correct: ‘Just because you are smarter than I am doesn’t make you right.’

Finally, Michael and Merete’s exceptional personal warmth and hospitality towards collaborators and visitors, both at Los Alamos and in Denmark, are fondly recalled by all.

John D. Anderson

Alfred Scharff Goldhaber

Terry Goldman

Peter W. Milonni