Harry L. Swinney: Nonlinear science and chaos pioneer

Harry Leonard Swinney passed away peacefully at his home in Austin, Texas, on July 13, 2026, at the age of 87. Harry was an exceptional experimental physicist, well-known for elegant studies of instabilities, nonlinear dynamics, chaos and pattern formation in a wide variety of fluid, chemical, and granular systems, work whose influence propagated into numerous scientific and engineering disciplines well beyond the particular problems that prompted it. The late Russell Donnelly of the University of Oregon used to say, “Harry is a prince”; Russ meant it, in the spirit of the tenth-century Persian poet Ferdowsi, as a compliment affirming the nobility, dignity, integrity, and grace with which Harry pursued his science and treated everyone he worked alongside.