Jerry Gollub
Jerry Gollub was a remarkably creative physicist who conducted pioneering experiments in nonlinear dynamics, including the first experiments that demonstrated the transition from order to chaos in fluid systems. His experiments contributed greatly to the understanding of complex dynamical behavior, including chaos and fractal growth patterns in diverse systems. His lucid papers and lectures led to his being widely sought as a lecturer at universities and international conferences.
Jerry was born in St. Louis, Missouri, on 9 September 1944. He died on 8 June 2019. He is survived by his wife, Diane Nissen, a daughter, a son, and four grandchildren. He graduated with an AB degree from Oberlin College in 1966 and with a PhD from Harvard University in 1971; his PhD advisor was Michael Tinkham. His primary appointment for his entire professional career was at Haverford College (1971–2012), where in 1979 he was named the John and Barbara Bush Professor of Physics. His steadfast commitment to undergraduate education and to Haverford College led him to decline offers of professorships at several major research universities.
Jerry mentored more than 100 undergraduates who worked in his Haverford laboratory with postdocs and with graduate students from the University of Pennsylvania, where he was an adjunct professor. Jerry was a pioneer in conducting world-class research at an undergraduate institution, and in 1985 he became the first recipient of the American Physical Society (APS) Award for Research at an Undergraduate Institution. He also held visiting appointments at the University of Paris VII (1985), Ecole Normale Supèrieure (Paris, 1991), and the Weizmann Institute of Science (1997–98).
My fondest memories of Jerry are from the period 1974–75, when we collaborated in an experiment designed to test Lev Landau’s 1944 prediction that the transition to turbulence would occur through an infinite sequence of instabilities as the Reynolds number was increased. Our experiments, conducted at the City College of New York, yielded time series of the fluid velocity measured at a point between concentric cylinders. When the inner cylinder rotation rate (proportional to Reynolds number) was increased, power spectra of the velocity time series revealed a transition from time-independent flow to a state characterized by a single frequency, in accord with the Landau picture. At a higher Reynolds number, a second frequency component, incommensurate with the first, appeared in the power spectrum, just as Landau anticipated. However, with further increase in Reynolds number, the spectra contained increasing broadband noise but no additional discrete frequency components. The noisy behavior differed from the expected Landau scenario, but the observation was consistent with models and analyses of chaos developed in the 1960s and 1970s. In our intense collaboration in 1974–75, Jerry and I developed a deep friendship and a research style and purpose that we sustained through our careers.
In the 1980s Jerry’s group at Haverford developed a technique for visualizing spatial patterns in convecting fluids. Jerry and his team used the technique to investigate how competition between different spatiotemporal modes led to chaos. In the late 1980s Jerry used particle tracking methods to characterize chaotic mixing in time-periodic convective flows, the formation of fractal and dendritic structures in solidification processes, and pattern formation and chaos in surface waves. He also conducted a series of imaginative experiments on the dynamics of granular materials. In 2008–09 Jerry was Leverhulme Visiting Professor at Cambridge University, where he collaborated with Raymond Goldstein, who had developed green algae as model organisms for biological fluid dynamics. Their experiments revealed diffusive yet non-Gaussian tracer statistics in suspensions of swimming microorganisms.
In 1983 Jerry became an APS Fellow, and in 2003 he was awarded the APS Fluid Dynamics Prize “for his elucidation of chaos, instabilities, mixing and pattern formation …" He also served for three decades in many elected and appointed positions in APS, including the Council and the Executive Board. In 1993 Jerry was elected to the National Academy of Sciences, and in 2005–08 he served on the NAS Governing Council. In 2000–02 he cochaired the National Research Council study “Learning and Understanding: Improving Advanced Study of Science in US High Schools.”
Jerry Gollub is greatly missed by his many friends, students, postdocs, and other collaborators throughout the world. His innovative experiments on the complex dynamics of systems driven away from thermodynamic equilibrium will have lasting impact. He will also be remembered as a tireless advocate for high school and undergraduate science education, especially in physics, and for his contributions to the general good of the broad scientific community.
