This book explores a question which should have been bugging all physicists who have used quantum mechanics since its advent in the 1920’s – What does it mean? What is the relation between the particles we observe to the wave mechanics we use to reliably and correctly predict our observations? Its prime “heroes” are Bell, Bohm, Bohr, and Einstein, though many others are brought into the picture. The Copenhagen interpretation, pilot waves, many worlds, Bell’s theorem, EPR, decoherence, superposition, entanglement, determinism, measurement, etc., are repeatedly qualitatively discussed. A great deal of history, philosophy, politics, and personalities, are fruitfully incorporated. The problem of quantum measurement is repeatedly brought up, from the views of the various authors mentioned and, at the book’s end, the author concludes: he doesn’t know what it means, a quandary with which I concur. The book is primarily aimed at the non-physicist, and so there is no mathematics or specific ideas such as the relation between “particle” and its “pilot wave”, or the meanings of “decoherence” and “entanglement”. But the book is a good read and is highly recommended for the physicist who wishes to question the foundations of his subject. Certainly, it refreshed many questions from my long-ago student days and raised new questions for me to think about. The questions are all there; the answers are yet to come.

Alvin M. Saperstein, Emeritus Professor of Physics,
Wayne State University
Detroit MI 48202

The articles in this issue represent the views of their authors and are not necessarily those of the Forum or APS.