Jerrold R. Zacharias

Jerrold Reinach Zacharias (January 23, 1905 – July 16, 1986) was an American physicist and institute professor at the Massachusetts Institute of Technology, as well as an education reformer. His scientific work was in the area of nuclear physics.

Biography Jerrold Zacharias was born on January 23, 1905, in Jacksonville, Florida.

During World War II, Zacharias was involved in both the Radiation Laboratory at MIT and the Manhattan Project. In the former he helped develop practical radar uses for the United States Navy and in the latter he was head of an engineering division at Los Alamos Laboratory.

Zacharias developed the first practical version of the cesium-beam clock, often called an "atomic clock". Developed in 1956, it later became the internationally accepted standard for timekeeping. Zacharias continued to push for educational reform throughout the 1960s and 1970s through such projects as Elementary Science Study and the educational TV series Infinity Factory. He was also the founder of Education Development Center, a global nonprofit that develops science and math curricula.

Zacharias died in 1986 at age 81. Zacharias' wife, Leona Zacharias was a scientist, researcher, and lecturer at Massachusetts Eye and Ear.

Katie Hafner is their granddaughter.