Daniel T. Valentine Ph.D. is Professor Emeritus and was Professor and Chair of the Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York. He was also Affiliate Director of the Clarkson Space Grant Program of the New York NASA Space Grant Consortium, a program that provided support for undergraduate and graduate research. His Ph.D. degree is in fluid Mechanics from the Catholic University of America. His BS and MS degrees in mechanical engineering are from Rutgers University. Dr. Valentine is also co-author of Aerodynamics for Engineering Students (Butterworth Heinemann).Brian Hahn was a professor in the Department of Mathematics and Applied Mathematics at the University of Cape Town. In his career, Brian wrote more than 10 books for teaching programming languages to beginners.