Walter John Jr.

1924 - 2023

Walter John Jr.
February 16, 1924 - April 14, 2023
Dr. Walter John Jr., 99, of San Francisco, California, passed away on April 14, 2023. A distinguished aerosol physicist, he conducted groundbreaking research on air pollution, including the study of airborne particles and the design of instruments to measure air pollution.
Walter John Jr. was born in Newkirk, Oklahoma, on February 16, 1924, to Walter John Sr., an immigrant from China, and Carrie Hollingsworth John. He spent two years in China during his youth and later attended Central High School in Oklahoma City, graduating third in his class of 421. Walter's interest in physics was sparked by a high school teacher. He earned a BS in Physics with honors from California Institute of Technology (Caltech) in 1950, which he attended on the G.I. Bill. In 1955 he was awarded a PhD in Physics from the University of California, Berkeley. Walter met his wife of 69 years, Bay Area artist Carol Salin John, when they both lived in the International House at UC Berkeley.
The American Association for Aerosol Research awarded Dr. John the Benjamin Y.H. Liu Award, one of its highest honors, in 2006. The award "recognizes outstanding contributions to aerosol instrumentation and experimental techniques that have significantly advanced the science and technology of aerosols." The award presentation stated, "Both a gentleman and a scientist, always curious, always cheerful, and wonderfully inventive, Walter has been an inspiration and mentor to many."
During World War II, Walter served in the U.S. Army from 1943 to 1946 in the forward headquarters unit of the 69th Infantry Division. His unit traversed Europe to the Elbe River, and he was present at the historic meeting of American and Soviet military generals in April 1945. Walter was awarded the Bronze Star in 1945 for meritorious service. While proud of his military service, Walter later became a committed pacifist and was active in the anti-war movement during the Vietnam War era.
Walter spent much of his career as a Research Scientist at the California Department of Public Health from 1974 to 1992, where he headed the aerosol and microscopy laboratories and consulted on the development of aerosol sampling instruments. He subsequently founded the company Particle Science, and worked with fellow scientist Susanne Hering to conduct aerosol research and develop air pollution measurement equipment that is still widely used, including in U.S. national parks. Walter held two patents for the measurement equipment he developed.
He served on the Board of the American Association for Aerosol Research from 1987 to 1992 and as General Conference Co-chair of the organization's 1992 Annual Meeting. He served on the editorial boards of several journals. He became a fellow of the American Physical Society in 1962 based on his research in nuclear physics. He has over 100 publications in journals and books.
From 1958 to 1971 Walter was Senior Physicist and Nuclear Reactor Research Group leader at the Lawrence Livermore National Laboratory, where he conducted research in experimental nuclear physics, the high point being the discovery of a new mode of fission in Fermium (Element 100). In the 1970s, his professional career transitioned to aerosol science, sparked by the opportunity to study airborne particles contributing to Los Angeles smog. He was Professor and Chairman of the Physical Sciences Department, California State College, Stanislaus, CA from 1971 to 1974. In addition, he taught courses during his career at the University of California, Berkeley, and the University of Illinois Urbana-Champaign.
A devoted husband, father, and grandfather, Walter is survived by his wife Carol, also of San Francisco; children Kenneth John (wife Kathy) of Arlington, VA, Leslie John (husband Greg Blackman) of Media, PA, Laura Ryle (husband Clint) of Santa Cruz, CA, and Claudia Shearer of San Francisco; and grandchildren Augie Blackman, Rachel Blackman, Rebecca Hoskins (husband Ward), Dean Shearer, and Luke Shearer.
Walter will be remembered for his brilliant mind, sense of humor, and love of family gatherings and outings, including vacations at Stinson Beach north of San Francisco and Lewes, DE. He and Carol enjoyed international travel, including to Amsterdam, China, Egypt, Greece, Italy, and Japan. He strongly encouraged Carol's career as an artist, appreciated the fine arts, especially ballet and painting, was an ardent San Francisco 49ers fan, and enjoyed swimming, long walks, and taking family and landscape photographs. Growing up, Walter played the violin and became a lifelong enthusiast of classical music, notably Mozart string quartets.
Memorial gifts in honor of Dr. John can be made to the Food Bank of Contra Costa and Solano in Concord, CA.