Dr. Siegmund Brandt is Professor Emeritus of Physics and Dr. Hans Dieter Dahmen is Professor Emeritus of Theoretical Physics at the University of Siegen. Their fields of research are the experimental and theoretical physics of elementary particles, respectively. They are joint authors of several textbooks, among them i? The Picture Book of Quantum Mechanicsi? (3rd edition, Springer, 2001). Dr. Tilo Stroh took his Ph.D. with a thesis on computation quantum mechanics under Hans Dahmen.