Richard C. Tolman - Biography

Biography

Tolman was born in West Newton, Massachusetts. His brother was the behavioral psychologist Edward Chace Tolman. Richard studied chemical engineering at the Massachusetts Institute of Technology, receiving his bachelor's degree in 1903 and Ph.D. in 1910.

In 1912, he coined the concept of relativistic mass by writing that "the expression m₀(1 - v2/c2)-1/2 is best suited for the mass of a moving body." In a 1916 experiment, Tolman demonstrated that electricity consists of electrons flowing through a metallic conductor. A by-product of this experiment was a measured value of the mass of the electron. Overall, however, he was primarily known as a theorist.

Tolman was elected a Fellow of the American Academy of Arts and Sciences in 1922. The same year, he joined the faculty of the California Institute of Technology, where he became professor of physical chemistry and mathematical physics, and later dean of the graduate school. An early student of Tolman's at Caltech was the American theoretical chemist Linus Pauling, to whom he taught the pre-wave-mechanics quantum theory.

In 1927, Tolman published a text on statistical mechanics whose background was the old quantum theory of Max Planck, Niels Bohr, and Arnold Sommerfeld. In 1938, he published a completely new work, covering in detail the application of statistical mechanics to both classical and quantum systems. It was the standard work on the subject for many years, and is still of interest today.

In the later years of his career, Tolman became increasingly interested in the application of thermodynamics to relativistic systems, and cosmology, work that culminated in an important 1934 monograph. That monograph showed that black body radiation in an expanding universe cools but remains thermal - a vital result for the properties of the cosmic microwave background. His investigation of the oscillatory universe hypothesis, which Einstein had proposed in 1930, resulted in its demise until the late 1960s.

During World War II, he served as scientific advisor to General Leslie Groves on the Manhattan Project. At the time of his death in Pasadena, he was chief advisor to Bernard Baruch, the U.S. representative to the United Nations Atomic Energy Commission.

Each year, the southern California section of the American Chemical Society honors Tolman by awarding its Tolman Medal "in recognition of outstanding contributions to chemistry."