Charles W. Clark is a Fellow of the National Institute of Standards and Technology (NIST) and is Co-Director of the Joint Quantum Institute of NIST and the University of Maryland. He has a Ph.D. in theoretical atomic, molecular and optical physics from the University of Chicago and has spent most of his career at NIST. Since 1997 he has run a summer course on solution of physics problems for first-year graduate students of UMD, and he is co-editor of the NIST Digital Library of Mathematical Functions, which will be used as a primary reference in some parts of the course.