Editor:Jurgen Audretsch was born in 1942 in Einbeck, Germany, and studied physics at the Universities of Tubingen and Freiburg. In 1980, he accepted a post as professor for theoretical physics at the University of Constance. His fields of activity were at first the General Relativity Theory and Quantum Field Theory, lately he has been doing research in theoretical quantum optics and the basic principles of quantum theory. Authors:Jurgen AudretschCarsten HeldRobert Low and Tilman PfauGerhard RempeHarald WeinfurterReinhard F. WernerErich JoostRainer BlattMichael Esfeld Professor Audretsch has not only published numerous scientific articles which appeared in scientific journals and books, he is also the author of a number of books for a wider readership interested in physics, which depict the relations between physics and philosophy or physics and theology. Professor Jurgen AudretschFakultat fur Physik der Universitat Konstanz Fach M 673 D-78457 KonstanzGermany