William Pepper was an American scientist born on August 16, 1893 in Philadelphia, Pennsylvania. He obtained his Ph.D. in physics from the University of Pittsburgh in 1916 and became a notable researcher in the field of optics. Pepper made numerous contributions to the development of optical instruments, particularly in the areas of spectroscopy and interferometry. He also served as the director of the Bartol Research Foundation from 1938 to 1957, where he conducted pioneering work on the application of optics in the study of atomic and molecular structures. Throughout his career, Pepper published over 100 scientific articles and was a member of several prestigious scientific societies. He passed away on May 4, 1972, leaving behind a lasting legacy in the field of optics.