Immediately after earning his Ph.D., in 1943, Harman joined the reaction kinetics department of Shell Oil in Emeryville, California.
He worked for six years as a Shell research chemist, in part studying free radical reactions in petroleum products.
Harman was married to the same woman for most of his life, a journalism student whom he met at a fraternity dance while at the University of California.
[5] In 1954, between his internship and residency in internal medicine, Harman became a research associate at the Donner Laboratory of Medical Physics at UC Berkeley,[2] where he was able to pursue the puzzle of the cause of aging.
He published his ideas on what he called the "mitochondrial theory of aging" in the April 1972 issue of the Journal of the American Geriatrics Society.