Rolf E. Hummel is a Professor Emeritus of Materials Science and Engineering at the University of Florida, Gainesville, USA. He received his Ph.D (Dr. rer.nat.) in 1963 from the University of Stuttgart, Germany and the Max-Planck Institute for Materials Research, also in Stuttgart. He has been at the University of Florida since graduation, only interrupted by Sabbatical stays in Japan, Korea, China, New Zealand, France, Vietnam, Germany, and Colorado. His previous publications include Optical Properties of Metals and Alloys (1971), Electro-and Thermo-Transport in Metals and Alloys (ed.),(1977), the two-volume Handbook of Optical Properties (ed.), (1996), and Understanding Materials Science 2nd Ed. (2004). His books are widely appraised for their easy understandability.