Mary Menzel

Mary (Tsingou) Menzel, age 97, passed away peacefully in her home on August 27, 2026, following a short illness.

Mary was born to Greek immigrant parents on October 14, 1928. She earned her undergraduate degree from the University of Wisconsin and a Master's degree in Applied Mathematics from the University of Michigan. In 1952, she accepted a position at Los Alamos National Laboratory, where she dedicated her entire 35-year career. It was also at Los Alamos where she met and married her husband of 63 years, Joseph L. Menzel.

Selected as one of the first programmers for the historic MANIAC computer, Mary spent her career solving complex problems in mathematics and applied physics. She was instrumental in computer programming and executing the simulations for the Fermi-Pasta-Ulam-Tsingou (FPUT) problem—a seminal achievement in computational physics that launched the field of nonlinear science and laid key groundwork for chaos theory.

Following retirement, Mary and Joe fully embraced life in Los Alamos. They enjoyed daily swims, regular walks to the Mesa Public Library, and warm lunches with the East Park Pool Lunch Ladies group.

Mary was preceded in death by her beloved husband, Joe, and her sister, Sally Peavy. She is survived by her two daughters, Dr. Ann Menzel (John Charney) of Pittsburgh, PA, and Dr. Carol Menzel of San Antonio, TX; eight grandchildren: Taylor Stine (Chelsea), Connor Charney (Elisa), Quinn Charney, Grant Charney, Kyle Anderson (Veda), Jillian Anderson, Lauren Anderson, and Nathan Anderson; and three great-grandchildren.

Memorial donations may be made to the Betty Ehart Senior Center in Los Alamos, NM.

A memorial service will take place on Monday September 21, 2026 at Rivera Family Funeral Home of Espanola, NM (305 Calle Salazar, 87532) at 11 am, followed by a light reception at the same address. A private family burial will follow at Santa Fe National Cemetery, where she will be interred with her beloved husband.