 In 1917, solar astronomer George Ellery Hale convinced Millikan to begin spending several months each year at the Throop College of Technology, a small academic institution in Pasadena, California, that Hale wished to transform into a major center for scientific research and education.A few years later Throop College became the California Institute of Technology (Caltech), and Millikan left the University of Chicago in order to become Caltech's "chairman of the executive council" (effectively its president).Millikan would serve in that position from 1921 to 1945.