Born in Milwaukee, Wisc., to Greek parents who had lived in Bulgaria before moving to the U.S., Tsingou graduated with a bachelor’s in mathematics and education from the University of Wisconsin, then a master’s in mathematics from the University of Michigan, and was hired by the Los Alamos National Laboratory in New Mexico, where she was a programmer of its home-built MANIAC — the Mathematical Analyzer Numerical Integrator and Automatic Computer. An early assignment: write the program for MANIAC to test a problem put forth by Enrico Fermi, John Pasta, and Stanislaw Ulam. The idea was to find a physics problem worthy of a simulation on the new computer; it was 1953, and the resulting experiment became known as the Fermi–Pasta–Ulam problem, a seminal experiment in the fields of chaos theory and scientific computing.
Wait: what about Tsingou? She’s the one who knew enough math to come up with the algorithm to simulate the problem, and program the computer to run it. Eh: she was just a woman — she was lucky to even get a thanks in a footnote for her “efficient coding of the problems” and running the computer. Fermi had actually died before the 1955 paper was published. Her contributions to the effort were not fully recognized until 2008, when physicist Thierry Dauxois wrote an article for Physics Today about the “mysterious lady” who did the actual work. He noticed the first page of the FPU report noted, “Report written by Fermi, Pasta, and Ulam. Work done by Fermi, Pasta, Ulam, and Tsingou.” Dauxois pointed out that “That remark, that Mary Tsingou took part in the numerical study but is not an author of the report, has puzzled many of the scientists who have read the paper. Her programming of a 1950s computer was not a trivial task. Why has her contribution received only a two-line acknowledgment?” His argument was enough that the problem was renamed, since then known as the Fermi–Pasta–Ulam–Tsingou problem. In 1958, Tsingou married another employee at the Lab, Joe Menzel.
The Laboratory itself finally cleared up the record in 2020, “A half-century after being mentioned in the footnote of a seminal physics paper, one of the Laboratory’s first computer programmers gets the recognition she deserves,” they wrote. “The scientists who wrote the paper — Enrico Fermi, John Pasta, and Stanislaw Ulam — were quickly recognized for the remarkable simulation,” they said …even though Fermi didn’t write the paper, since he was dead. But, they acknowledged, “Some of her coding work is used to this day.”
Still, Tsingou was paid poorly for her work — because she was a woman, that LANL article notes: “‘We as women were expected to be second rate,’ Tsingou says. She was repeatedly told by supervisors that they were trying to raise her salary to equal that of a man with her skills and experience; she never understood, she says, why they couldn’t just do it.” On the other hand, “We were doing this in the same way young men went into the military,” she said of women like her at the Lab. “We knew it was something that was important for the country.” She retired in 1991 after 40 years on the job. Back in the 1950s, “when you were married, you were only eligible for apartments,” she said in 2020, “and then when you were at least three months pregnant, you were eligible to apply for a house.” When pregnant with their first daughter, they were assigned a house. They never moved out. “This is our place,” she said in 2020. “This is our home.”
She said the mid-20th-century prognosticators at the Lab got it all wrong. “They thought nuclear energy was going to change the world,” she said. “But it’s the computers that have changed the world.” Joe died in 2021. Mary Tsingou Menzel died at their home in Los Alamos on August 27, at 97.