Daniel Kivelson, an emeritus professor of physical chemistry at UCLA, died of cancer in Los Angeles, California, on 23 January 2003. Throughout his career, he combined expertise in experimentation with fundamental theoretical analysis to make important advances in several fields of chemical physics. Those fields included microwave spectroscopy, electron spin resonance spectroscopy (ESR), nuclear magnetic resonance, low-energy electron–molecule scattering, dynamic light scattering, relaxation phenomena in liquids and viscoelastic fluids, and supercooled liquids and glasses.
Daniel was born in New York City on 11 July 1929. He was educated at Harvard University, where he received an AB in chemistry and physics (1949), an MS in physics (1950), and a PhD in chemical physics (1953). His doctoral research, with E. Bright Wilson, in molecular spectroscopy included development of the theory of internal rotation and centrifugal distortion applied to the microwave spectra of small molecules.
In 1955, he joined the chemistry faculty at UCLA, where he spent the remaining 48 years of his career. During that time, Daniel served as department chair (1975–78) and chair of the UCLA academic senate (1980–81).
In the 1960s, Daniel concentrated his research on ESR studies and used both theoretical and experimental approaches. One of his papers, a “citation classic” that was published in 1960 in the Journal of Chemical Physics , applies linear-response theory to develop a complete and systematic approach to understanding ESR linewidths in liquids. That paper was the beginning of his long fascination with liquid dynamics.
Daniel had moved into studies of liquids by the early 1970s. He concentrated on molecular rotations and determined the effect of molecular reorientation and relaxation dynamics on dielectric phenomena by probing them simultaneously with ESR and optical methods. Thirty years later, his contributions to depolarized light scattering from viscoelastic liquids, and specifically to the coupling of shear modes in those systems, are still regarded as the definitive work in the field.
In the late 1980s, Daniel began to focus on the special nature of supercooled liquids; that work led to his interest in the glass transition and the nature of the glassy state. In the 1990s, he developed a new physical picture for the glass transition: The liquid prefers a local structure but is prevented by geometric frustration from crystallizing via a critical phase transition into a periodic structure consistent with the local structure. Although it has proved difficult to tie his picture to a concretely defined order parameter for the glass transition, the idea of an “avoided critical point” is consistent with much of the known phenomenology and has had a profound influence on the field. As he wrote in 1997 (Journal of Physical Chemistry ), “I have never been as excited by my science as with this work because it represents an attempt to develop a novel, initial description of important, but still not well-understood phenomena.” He continued to pursue that research with energy and enthusiasm until shortly before his death.
Daniel was not committed only to research. His devotion to teaching was recognized by a university teaching award in 1969. He was constantly seeking new and better ways to present fundamental ideas to his students; every year, he thoroughly revised the detailed notes he distributed. Although he had many graduate students and postdocs, undergraduates played a significant role in his experimental research. After nominally retiring in 2000, Daniel remained active in research and continued to teach undergraduates.
In recognition of his remarkable contributions in research, teaching, and university service, Daniel received the UCLA College of Letters and Science Award in 1987. His scientific awards included the American Chemical Society’s California Section Award in 1967 and the American Physical Society’s Irving Langmuir Prize in Chemical Physics in 1999.
The Kivelson family has been described as a “distinguished academic dynasty.” Daniel’s wife, Margaret, a professor at the Institute of Geophysics and Planetary Physics at UCLA, and son, Steven, a physics professor at UCLA, each collaborated with Daniel on a few papers. Daniel’s daughter, Valerie, is an associate professor of history at the University of Michigan. One obsession of the family is Turkoman rugs; Daniel, together with his wife, was an avid collector of Turkoman rugs. The family lent pieces from their collection to various museums.
Daniel believed in a just society and was dedicated to the elevation of the civil rights, well-being, and human dignity of all people. He was deeply disturbed by many recent developments, both in the US and abroad. He set an example that has been a source of inspiration to many. His ambition was not to win prizes and attract attention (although he did), but to do beautiful science, to enjoy doing it with friends, and to instruct new generations of scientists.
For more than four decades, those of us fortunate to be Daniel’s friends and colleagues, both junior and senior, sought him out for his advice, scientific insight, and stimulating company. Daniel made a lasting mark on everyone who interacted with him closely. We miss his penetrating intellect, conspicuous originality, relentless honesty, loving generosity in thought and action, infectious love for and appreciation of the richness of life’s offerings, deft sense of humor, and megawatt smile.
To honor Daniel and to remember his singular ability to stimulate undergraduates in research, the UCLA department of chemistry and biochemistry has established a fund in his name to provide undergraduate research fellowships.
