Niels Bohr: Collected Works, Volume 13: Cumulative Subject Index documents aspects of Niels Bohr's varied life and work in the form of a cumulative subject index, with emphasis on his scientific contributions in the field of physics. The general organization of the material is thematic rather than strictly chronological, allowing for the presentation of each paper (or group of papers) along with other relevant material such as drafts, notes, letters, and other items. The book is illustrated with rare photos and includes explanatory notes as well as a bibliography. The bibliography is restricted to the versions of Bohr's publications reproduced in this volume and encompasses a wide range of topics in physics, from the determination of the surface tension of water by the method of jet vibration to the electron theory of metals and of thermoelectric phenomena; the theory of the decrease of velocity of moving electrified particles on passing through matter; the constitution of atoms and molecules; and the spectra of helium and hydrogen. Bohr's other papers focus on the effect of electric and magnetic fields on spectral lines; the quantum theory of radiation and the structure of the atom; the polarization of radiation in the quantum theory; and collisions between atomic systems and free electrical particles. This monograph will be useful to students, practitioners, and researchers interested in Bohr's life and work in general and in quantum mechanics in particular.

The life of Niels Bohr spanned times of revolutionary change in science itself as well as its impact on society. Along with Albert Einstein, Bohr can be considered to be this century's major driving force behind the new philosophical and mathematical descriptions of the structure of the atom and the nucleus. Abraham Pais, the acclaimed biogrpaher of Albert Einstein, here traces Bohr's progress from his well-to-do origins in late nineteenth-century Denmark to his position at centre stage in the world political scene, particularly during the Second World War and the development of atomic weapons. Pais' description moves through the science as it was before Bohr, as it became because of Bohr, and thence to Bohr's scientific and philosophical legacy. That legacy is contained both in theory as it is now universally enshrined, as well as in its practice in such great Danish institutions as Riso. But more than that, Pais captures the essence of Bohr, the intensely private family figure who, despite appalling personal tragedy, became one of the most loved cultural figures of recent times.

The Niels Bohr Collected Works are now complete with the publication of Volume 12, Popularization and People (1911-1962).Niels Bohr is generally regarded as one of the most influential physicists of the twentieth century. The following are only some of the high points. In 1913, Bohr proposed a revolutionary model of the atom breaking with classical conceptions of physics. In 1921, he established the Institute for Theoretical Physics at the University of Copenhagen, which became the centre for the new physics visited by the younger generation of physicists from all over the world. From 1927, he oversaw the development leading to the "Copenhagen interpretation" of quantum mechanics which for Bohr formed the foundation for an epistemology valid beyond physics based on Bohr's complementarity concept. In 1939, he explained the mechanism of nuclear fission. Finally, from 1943 until the end of his life in 1962, he carried out a personal political mission to establish an open world between nations which he considered to be necessary in view of the existence of the atomic bomb.All these contributions are amply documented in the earlier volumes of the Niels Bohr Collected Works. This last volume documents Niels Bohr as a person and his efforts to explain quantum physics and its implications to physicists and non-physicists alike. While his activity over many years in the area of superconductivity illustrates his striving for synthesis in physics, his encyclopaedia articles and radio speech for Scandinavian gymnasium students document his effort to make quantum physics and its implications understandable to the general public. The bulk of the volume comprises Bohr's many published writings about his predecessors (for example Isaac Newton), teachers and colleagues (for example Ernest Rutherford and Albert Einstein), family and friends. These writings, which include several rare pieces of autobiogaphy, bring new perspectives to Bohr's life and document his substantial social network, both internationally and within his beloved Denmark.In addition to Bohr's publications reproduced in Parts I and II, the volume includes a more brief Part III with selected correspondence, as well as an inventory of relevant manuscripts. It concludes with a bibliography of Bohr's many publications, chronologically arranged with references to where they can be found in the various volumes of the Collected Works. The volume is illustrated with many new photographs.* Niels Bohr * Collected Works * Archival Documents * Original Photographs

This collection of articles, which were first published in 1958 and written on various occasions between 1932 and 1957, forms a sequel to Danish physician Niels Bohr’s earlier essays in Atomic Theory and the Description of Nature (1934). “The theme of the papers is the epistemological lesson which the modern development of atomic physics has given us and its relevance for analysis and synthesis in many fields of human knowledge. “The articles in the previous edition were written at a time when the establishment of the mathematical methods of quantum mechanics had created a firm foundation for the consistent treatment of atomic phenomena, and the conditions for an unambiguous account of experience within this framework were characterized by the notion of complementarity. In the papers collected here, this approach is further developed in logical formulation and given broader application.”

During this period Bohr's researches had a double aim: to develop a consistent and adequate quantum theory and to explain the structures and properties of the elements of the periodic system. ``The Correspondence Principle'' contains the papers and manuscripts dealing mainly with the elaboration of the general quantum theory.

It is now a little more than 11 years since the idea of writing a personal and scientific biography of H. A. Kramers took hold of me. A few days earlier I had been lecturing, in a course on field theory, on the renormalization proce dures of relativistic quantum field theory. Since the students had considerable trouble understanding the physical basis of the procedure, at the end of the lecture T explained that renormalization is not an exclusive quantum or relativistic procedure. A careful treatment of classical electron theory as started by Lorentz and developed in detail by Kramers also requires re normalization. The students appeared quite interested and I promised them that I would explain all this in more detail in the next lecture. I could have looked up this material in Kramers' book, but I remembered that Kramers had stressed this idea in a course I had attended in Leiden in 1938-1939. I did dig up some of these old notes and, although they were considerably less transparent than my recollection seemed to indicate, they reminded me force fully of the thrilling days I had spent in Leiden with Kramers. Kramers' deep insight and originality were apparent even when distorted by my opaque notes. The students had never heard of these ideas of Kramers' and were totally unaware of his work in field theory.