This volume covers one of the most thrilling two-year periods in twentieth-century physics, as matrix mechanics-developed chiefly by W. Heisenberg, M. Born, and P. Jordan-and wave mechanics-developed by E. Schroedinger-supplanted the earlier quantum theory. The almost one hundred writings by Einstein, of which a third have never been published, and "This huge volume holds many surprises for readers, even those familiar with much of the recent literature on Einstein's science, politics, and public life."---David E. Rowe, Metascience