Smith, Sinclair

Born Chicago, Illinois, USA, 24 March 1899

Died Pasadena, California, USA, 8 May 1938

Sinclair Smith is best known to astronomers for his measurement of the gravitating mass of the Virgo cluster of galaxies in 1937, which confirmed the very large mass-to-light ratio that had been found for the Coma cluster by Fritz Zwicky in 1933. Smith is a less familiar name in twentieth-century cosmology for two reasons: First, his work was largely in the area we would now call instrumental physics, rather than observational astronomy, and, second, he died tragically early, of cancer.

Smith received his bachelor’s degree from the California Institute of Technology (Caltech) in 1921 and his Ph.D. in 1924, also from Caltech, for work with John Anderson on electrically exploded wires as a method of obtaining laboratory spectra at high excitation and ionization energies. He remained in the physics laboratory of Mount Wilson Observatory the rest of his life, apart from a year (1924/1925) at the...