Fritz Zwicky

Fritz Zwicky (February 14 1898 – February 8 1974) was a Swiss astronomer, born in Varna, Bulgaria to Swiss parents. In 1925 he came to the California Institute of Technology in the United States and remained there for the rest of his life, though he remained a Swiss citizen. He was the first to use the virial theorem to deduce the existence of dark matter. He proposed the use of gravitational lenses. With Walter Baade, he came up with the idea that supernovas could create neutron stars and produce cosmic rays. He also pioneered and promoted the use of Schmidt telescopes. In his later career, he compiled a Catalogue of Galaxies and of Clusters of Galaxies (CGCG). He won the Gold Medal of the Royal Astronomical Society in 1972. Zwicky, Fritz