Since its inception in the early part of the twentieth century, quantum physics has fascinated the academic world, its students, and even the general public. In fact, it is – or has become – a highly interdisciplinary eld. On a topic such as “the physicsof the atom” the disciplines of physics, philosophy,and history of science interconnect in a remarkable way, and to an extent that is revealed in this volume for the rst time. This compendium brings together some 90 researchers, who have authored approximately 185 articles on all aspects of quantum theory. The project is truly international and interdisciplinary because it is a compilation of contributions by historiansofscience,philosophers,andphysicists,all interestedinparticularaspects of quantum physics. A glance at the biographies at the end of the volume reveals author af liations in no fewer than twenty countries: Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany,Greece, Italy, Israel, the Netherlands, New Zealand, Norway, Poland, Portugal, Spain, Switzerland, the United Kingdom and the United States. Indeed, the authors are not only international, they are also internationally renowned – with three Physics Nobel Prize laureates among them. The basic idea and motivationbehind the compendiumis indicatedin its subtitle, namely,to describe in concise and accessible form the essential conceptsand exp- iments as well as the history and philosophy of quantum physics. The length of the contributions variesaccording to the topic, and all texts are written by recognized experts in the respective elds.