Mary Tsingou Menzel, a mathematician and pioneering computer programmer whose work was instrumental in a landmark 1955 physics experiment, died on August 27 at her home in Los Alamos. She was 97. Her death was confirmed by her daughter Ann Menzel.
Ms. Tsingou joined the Los Alamos Scientific Laboratory in New Mexico in 1952, shortly after earning a mathematics degree from the University of Wisconsin. At the time, Los Alamos was a front-runner in Cold War scientific research and nuclear development. She initially worked as a “human computer” performing basic calculations, a task she found unchallenging. She soon transitioned to programming MANIAC I, the laboratory’s first fully electronic computer, which used punched tape as input. This allowed her to translate complex mathematical equations into machine-readable code, a highly technical and innovative process for the era.
Her programming skills enabled one of the first major computational physics experiments known now as the Fermi-Pasta-Ulam (FPU) problem. This project, designed by physicists Enrico Fermi, John Pasta, and mathematician Stanislaw Ulam, simulated the motion of particles connected by springs to study energy distribution in nonlinear systems. Contrary to expectations that the energy would distribute randomly, the experiment revealed unexpected ordered behaviors and recurrences. This finding was significant in developing nonlinear science and laid the groundwork for chaos theory, influencing diverse fields from cardiac rhythms to weather forecasting and economic modeling.
Despite her crucial contributions, Ms. Tsingou was not initially credited as a coauthor of the published report but was acknowledged only in a footnote for her “efficient coding.” She later explained that although the scientists set up the equations, she was responsible for the entire programming process. Retrospective recognition of her role grew after French physicist Thierry Dauxois highlighted her work in 2008, leading to broader use of the term “Fermi-Pasta-Ulam-Tsingou” to acknowledge her contribution.
Born in Milwaukee in 1928 to Greek immigrant parents, Mary Tsingou and her family moved to Bulgaria during the Great Depression before returning to the United States during World War II. She faced linguistic challenges in school but excelled in mathematics. After completing a master’s degree in mathematics at the University of Michigan in 1955, she continued to apply her skills at Los Alamos, supporting thermonuclear research and later contributing to the Strategic Defense Initiative.
Ms. Tsingou married Joseph Menzel, a Los Alamos security officer, in 1958; he passed away in 2022. She is survived by two daughters, Ann and Carol, eight grandchildren, and three great-grandchildren.
Reflecting on her decades-long career, Ms. Menzel expressed no resentment about initially being omitted from the experiment’s formal credit. “I was just doing the job,” she said. “I was glad to get paid.”