Jerrold R. Zacharias

On July 16, 1986 Jerrold R. Zacharias died unexpectedly at his home in Belmont,Massachusetts in his 81st year. Dr. Zacharias’ career spanned several areas of physics during his extraordinarily productive life, In the context of time and frequency control his work on the radio frequency spectra of atoms and his superb competence at experimental work led to the successful development of the first atomic clocks and their subsequent manufacture. During the era beginning in the mid 1940’s, prior to the space age, he foresaw the possibility of testing Einstein’s theory of relativity with atomic clocks and began working on clock concept that directly led to present cesium devices. He was truly the Godfather of the atomic clock.