Hans A. Bethe

A compilation of previously unpublished lectures delivered at the International Centre for Theoretical Physics by the pioneers and creators of modern physics --Bethe, Dirac, Heisenberg, Wigner, Klein and Landau (the sixth delivered by E Lifshitz). By sharing with us their own lives of physics, these outstanding physicists convey the sense of total dedication, the pleasure and elegance of scientific creation at its peak. Readers would acquire a deeper sense of the scope and nature of physics, and the insights of its fascinating diverse disciplines as the developments of modern physics are being unfolded through history.

Nearly all of this book is taken from an article prepared for a volume of the Encyclopedia of Physics. This article, in turn, is partly based on Dr. Norbert Rosenzweig's translation of an older article on the same subject, written by one of us (H. A. B.) about 25 years ago for the Geiger-Scheel Handbuch der Physik. To the article written last year we have added some Addenda and Errata. These Addenda and Errata refer back to some of the 79 sections of the main text and contain some misprint corrections, additional references and some notes. The aim of this book is two-fold. First, to act as a reference work on calcu­ lations pertaining to hydrogen-like and helium-like atoms and their comparison with experiments. However, these calculations involve a vast array of approxi­mation methods, mathematical tricks and physical pictures, which are also useful in the application of quantum mechanics to other fields. In many sections we have given more general discussions of the methods and physical ideas than is necessary for the study of the H- and He-atom alone. We hope that this book will thus at least partly fulfill its second aim, namely to be of some use to graduate students who wish to learn "applied quantum mechanics". A basic knowledge of the principles of quantum mechanics, such as given in the early chapters of Schiff's or Bohm's book, is presupposed.

Mesons and Fields, Volume 2: Mesons is a comprehensive book written by Silvan S. Schweber. This book is a sequel to the first volume of Mesons and Fields and focuses on the study of mesons, which are subatomic particles that have a mass between that of an electron and a proton. The book begins with an introduction to the basic concepts of meson physics and then delves into the mathematical and theoretical aspects of meson interactions. The author provides a detailed account of the history of meson physics, including the discovery of mesons and their role in nuclear interactions. The book covers various topics related to mesons, such as the properties of mesons, meson decay, meson-nucleon interactions, and meson spectroscopy. The author also discusses the experimental techniques used to study mesons and the theoretical models used to describe their behavior. The book is written in a clear and concise manner, making it accessible to both students and researchers in the field of particle physics. It includes numerous diagrams, tables, and equations to aid in the understanding of the material. Overall, Mesons and Fields, Volume 2: Mesons is an essential resource for anyone interested in the study of mesons and their role in particle physics. In Two Volumes. Volume 1, Fields; Volume 2, Mesons. This scarce antiquarian book is a facsimile reprint of the old original and may contain some imperfections such as library marks and notations. Because we believe this work is culturally important, we have made it available as part of our commitment for protecting, preserving, and promoting the world's literature in affordable, high quality, modern editions, that are true to their original work.

As the head of the theory group at Los Alamos, Hans A. Bethe played a

This book was written twenty years ago, but we are leaving it unchanged - not because little has happened to the subject, but because so much has happened that any change would require very major rewriting. On the other hand, no other book on the subject seems to have appeared and we hope this paperback edition will be of some use to a younger generation - if not for another twenty years, at least until someone else has the patience to write a new book. Although we have added no new material we have corrected some misprints. We have added new references only where they correct actual errors. We are grateful to Drs. G. Feinberg, M. Inokuti, Y. Kim, and A. Petermann for pointing out errors. Nearly all of this book is taken from an article prepared for a volume of the Encyclopedia of Physics. This article, in turn, is partly based on Dr. Norbert Rosenzweig's translation of an older article on the same subject, written by one of us (H. A. B.) about 25 years ago for the Geiger-Scheel Handbuch der Physik. To the article written last year we have added some Addenda and Errata. These Addenda and Errata refer back to some of the 79 sections of the main text and contain some misprint corrections, additional references and some notes.