Bio: Sidney Rosen is presently Professor Emeritus of Astronomy at the University of Illinois. He is still teaching, though, in a special undergraduate program called "Unit 1." His special field, however, is not astronomy but the history of science. When he finished his Ph.D. at Harvard in 1955 (on the G.I. Bill), Rosen's wife Dorothy, a children's librarian in the Boston Public Library at the time, persuaded him to write a book about Galileo, and to his surprise, Little, Brown bought it. The book received good reviews and went through 16 printings. The success of this book sparked similar bios of the great early Renaissance physician Paracelsus, who is considered the "father of chemotherapy"; the astronomer Johannes Kepler, who first worked out the planetary orbits; and R. Buckminster Fuller, designer of the geodesic dome. He has an AB degree from what is now the University of Massachusetts at Amherst. Rosen was in the Army Air Corps Medical Department during WWII. He and his wife have written about 15 publications, some of which they co-authored. Their latest publication is the Belle Appleman adult mystery series, Death and Blintzes and Death and Strudel, all of which take place in Boston during the Great Depression of the 1930s.