Martin Goldstein, whose 1969 paper caused a paradigm shift in our understanding of the physics of viscous liquids and glass, died of complications from cancer on 23 April 2014 at his home in New York City. Only weeks earlier he had been working on a paper on the specific heat of glasses and had participated in a symposium on the physics of the glassy state at Yeshiva University, where he had taught physical chemistry from 1965 to 1987.
Marty was born on 18 November 1919 in the Bronx, New York. He obtained a BSc from the City College of New York in 1940, then served in the US Army during World War II. Under the supervision of Ralph Halford, he obtained his PhD from Columbia University in 1950 on a study of fibrous proteins with polarized IR radiation. He did postdoctoral work at Harvard University and the Brooklyn Polytechnic Institute.
During five years at the Mellon Institute of Industrial Research in Pittsburgh, Pennsylvania, Marty developed an interest in the properties of glass and the glassy state itself. He then spent a year and a half working on solar energy projects at the National Physical Laboratory of Israel. For the next four years, Marty was part of the basic research staff at the Ford Motor Co in Dearborn, Michigan, and worked on fundamental aspects of spontaneous relaxation of glass, such as volume relaxation of zinc chloride near its glass transition temperature. In 1965 he joined Yeshiva’s Belfer Graduate School of Science as a professor of chemistry.
An exceptionally modest man of great scientific depth and compassion, Marty profoundly influenced the thinking of many scientists interested in the consequences of molecular diffusion on the properties of condensed matter. He made numerous contributions to the understanding of how a glass forms when a liquid is cooled below its freezing point, with particular focus on configurational thermodynamics.
One such contribution was an entirely new perspective on viscous liquids and glasses. In his concept, which Marty modestly called a “potential-energy-barrier picture,” the potential energy of an N-atom system is plotted as a function of 3N atomic coordinates in a (3N + 1)-dimensional space. In Marty’s words, “The state of a system is represented by a point moving on the surface with a 3N-dimensional velocity whose average value is temperature dependent.” Each minimum in the hypersurface represents the state point of a liquid, with the structure of the liquids fluctuating between different state points. His approach changed the way we thought about glass formation and the nature of the glassy state.
Frank Stillinger and Thomas Weber gave mathematical description to Marty’s potential-energy surface, and their respective papers are often cited together in the literature on energy-landscape applications. Scientists working in diverse disciplines have used the potential-energy landscape to describe structure fluctuations of hydrated proteins, diffusion-controlled kinetics, rheology, nucleation and crystallization of liquids, aging of glass, atom clusters, and nanoparticles. Some groups have devoted decades of research to obtaining landscape predictions.
Another of Marty’s contributions was the discovery of molecular mobility in rigid molecular glasses, a phenomenon now known as the Johari–Goldstein process. He initiated the experiments and helped confirm the results, which showed that molecular motions in the glassy state do not require intramolecular degrees of freedom. His study also showed that segmental dynamics of polymers and other flexible molecules occurs in an intermolecular environment and hence involves overcoming intermolecular barriers.
Later in his career, Marty developed a second vocation: helping the public understand the methods and processes of science. He and his wife, Inge, now a special lecturer in environmental epidemiology at Columbia University, coauthored four books that elucidate to lay readers the methodology shared by scientists working in various fields: How We Know: An Exploration of the Scientific Process (Plenum Press, 1978), The Experience of Science: An Interdisciplinary Approach (Plenum Press, 1984), The Refrigerator and the Universe: Understanding the Laws of Energy (Harvard University Press, 1993), and How Much Risk? A Guide to Understanding Environmental Health Hazards (Oxford University Press, 2002). But the publication in which he took the most pride may have been the comic book, Comparing Infinities with Teddy, Ari and Pa, that he wrote and illustrated for his grandchildren; in it he used the concept of infinity to showcase the beauty and use of mathematics.
Those who knew Marty also knew his passion for fine prose, poetry, and wit. He published articles on Fyodor Dostoevsky, Anthony Trollope, and William Shakespeare and outperformed all his progeny in limerick slams.
We believe his potential-energy- barrier picture of liquids will be seen as an improvement on two-site models the same way that collective modes of vibrations (phonons) in solids are an improvement on independent modes of vibrations. Those who would use his scientific ideas to explain their findings would be, in their own way, celebrating his life.
