Paul E. Phillipson

Paul E. Phillipson, a theoretical physicist and leading researcher in the realms of nonlinear dynamics and biophysics, passed away peacefully on October 20, 2023, at his home in Boulder, CO, attended by family. Though actively working and traveling until very recently, a number of intersecting health challenges drew his activities to a close. His life was a testament to the power of knowledge, exploration, perseverance, and deep familial bonds.

Paul was born on May 22, 1933, in Newark, NJ, to the late Harry and Anna Zimetbaum Phillipson. After briefly attending Columbia High School in Maplewood, NJ, Paul entered the University of Chicago's Hutchins College at the age of 16, where he developed a life-long interest in classical literature, history, and humanities, completing a B.A. in Liberal Arts in 1953. He then shifted into scientific study at the University of Chicago, obtaining an M.S. in Physics in 1956 and later a Ph.D. in Physics in 1962, under the direction of Nobel laureate Robert S. Mulliken. His first postgraduate appointment was as Research Associate at the University of Michigan from 1961 to 1963.

In 1963 Paul began his long tenure in the Department of Physics at the University of Colorado, where he cultivated his research, taught innumerable courses, and held a series of positions: Assistant Professor and Alfred P. Sloan Fellow (1963-1967), Associate Professor (1967-1977), full Professor (1977-1998), and Professor Emeritus (1998 to 2023). Paul's research focused on nonlinear dynamics and biophysics, and he published many articles elucidating dynamical processes in macromolecular and physical systems. Over his career Paul collaborated with leading theoretical chemists, biochemists, and biophysicists such as Jeffries Wyman, Manfred Eigen, Enrico Di Cera, and Peter Schuster, with whom he co-authored the monograph "Modeling by Nonlinear Differential Equations: Dissipative and Conservative Processes" in 2009.

Soon after moving to Boulder, Paul met the love of his life, Patricia May Bradley of Pocatello, Idaho. They married in 1965 and, after establishing a home and family, pursued extensive opportunities to live and travel in Europe during sabbaticals and a series of visiting professorships. Their main European bases were Rome (1969, 1971-73, 1982-83), where Paul researched at the University of Rome, and Vienna (1983-2007), where he spent many semesters as Visiting Professor at the University of Vienna and Visiting Research Professor at the Austrian Academy of Sciences.

Paul and Pat extended these opportunities into explorations of numerous other European countries, often bringing along family members and friends and expanding their horizons. One of Paul's favorite locations was Greece, where he felt particularly close to the classical world. At the same time, Paul and Pat continued their engagements and friendships in Boulder, where Pat led the Physical Therapy department at the University of Colorado's Wardenburg Health Center. During his emeritus years, Paul kept up an active research agenda, biking into the office every day whenever he was in Boulder. Pat and Paul could also frequently be seen in local cafes battling it out over the chess board.

Besides his passion for travel, Paul was an avid photographer and had a strong affection for classical music, with a particular fondness bordering on obsession for opera. Over the years he developed deep and loving relationships with his wife's siblings, their spouses, and their extended families, and was a fixture at annual camping gatherings and other family reunions in Idaho. Wherever he was during his long and wide-ranging life, Paul remained firmly centered in his many interests and unfailingly devoted to family and friends. His conversational warmth, quick wit, and ready laughter will long be remembered by all who knew him.

In addition to his wife, Paul's survivors include his son Mark Phillipson (and spouse Scott Tebbetts); his daughter Andrea Vassiliadis; his grandson Nicholas Vassiliadis (and spouse Ozgu Vassiliadis); and his grandson Jack Vassiliadis. His sister Marcia Abby Phillipson Ross also passed away this year, but Paul is survived by two nephews, Robert Ross and Richard Ross. He also leaves behind numerous cherished members of his wife's extended family.

Paul's remains were cremated and, per his wishes, they will be scattered into the Atlantic Ocean later this year, during a private family ceremony.