Otto E. Rössler

Otto Eberhard Rössler was born in Berlin on 20 May 1940. His father, Otto Rössler, was an Austrian-born scholar of Semitic languages who had worked with the Ahnenerbe during the Nazi period and later became a professor at the University of Marburg. The son took a medical doctorate in 1966. After postdoctoral work at the Max Planck Institute for Behavioral Physiology and a visiting appointment at the Center for Theoretical Biology at the State University of New York at Buffalo, he joined the University of Tübingen in 1969 as Professor of Theoretical Biochemistry.

At Tübingen Rössler built an interdisciplinary career spanning theoretical biochemistry, chemistry and nonlinear physics. In 1976 he published An equation for continuous chaos in Physics Letters A, introducing the three-dimensional dynamical system now known as the Rössler attractor. The work grew out of conversations with Arthur Winfree and became one of the most widely taught examples of continuous chaos. In 1994 he was additionally appointed Professor of Chemistry by decree.

He held visiting positions in mathematics at the University of Guelph, at the Center for Nonlinear Studies at Los Alamos, in chemical engineering at the University of Virginia, in theoretical physics at the Technical University of Denmark, and in complexity research at the Santa Fe Institute. His later interests included endophysics, which treats the observer as part of the physical system, chaotic hysteresis, the Burning Ship fractal and questions of artificial universes and world-changing technology. Books associated with his name include Encounter with Chaos (1992), Endophysics: The World As An Interface (1998) and Chaos: The World of Nonperiodic Oscillations (2020). He authored or co-authored hundreds of scientific papers.

Rössler was married to Reimara Rössler, a professor of medicine. From the late 1980s the couple were locked in a long-running conflict with the University of Tübingen and the state of Baden-Württemberg over departmental transfer, teaching assignments and academic freedom. Reimara Rössler lost her university post in the mid-1990s after refusing a transfer. Otto Rössler, assigned in 1993 and 1994 to teach an introductory chemistry course for medical students, insisted on teaching his own material; he was replaced, repeatedly tried to lecture anyway and was removed by police on several occasions. A 1995 plan to compel him to undergo psychological testing was dropped after international academic protest. In August 2001 he was caught spray-painting the university auditorium as a protest. The disputes were widely reported in the German press.

Otto E. Rössler died in Tübingen on 5 October 2026, aged 86. A death notice in the Schwäbisches Tagblatt, carried on Südwest Presse Trauer and dated 15 October 2026, recorded his birth on 20 May 1940 and his death on 5 October 2026. The cause of death was not stated in public notices. English and German Wikipedia and the Nekrolog for October 2026 list the same date and place.

The Rössler attractor remains a staple of textbooks and courses on dynamical systems, chaos and nonlinear science, often placed beside the Lorenz attractor as a transparent example of continuous chaotic motion in three dimensions. Beyond that single discovery, Rössler helped keep open a conversation between biochemistry, physics and speculative philosophy through endophysics and related ideas. His later public advocacy against the Large Hadron Collider, though rejected by mainstream physics, made him briefly one of the most visible scientific dissenters of the late 2000s. For many students and researchers, his name is still synonymous with a simple, elegant picture of chaos.