Harlow ShapleyBorn 2 Nov 1885; died 20 Oct 1972 at age 86. American astronomerknown as “The Modern Copernicus,” who discovered the Sun's position in the galaxy. From 1914 to 1921 he was at Mt. Wilson Observatory, where he calibrated Henrietta S. Leavitt's period vs. luminosity relation for Cepheid variable stars and used it to determine the distances of globular clusters. He boldly and correctly proclaimed that the globulars outline the Galaxy, and that the Galaxy is far larger than was generally believed and centered thousands of light years away in the direction of Sagittarius. In the early 1920's, Shapley entered a “Great Debate” with Heber D. Curtis. They truly argued over the “Scale of the Universe.” |