Léon Rosenfeld

The following sections are included:

• Preface

• Contents

• List of Pictures

One way to get insight into the fascinating history of twentieth century physics and its inextricable entanglement with general history is to look at the life stories of particular individuals.¹ This book is a social-intellectual biography of the Belgian theoretical physicist, Léon Rosenfeld (1904–1974). In the history of science literature Rosenfeld is largely a blank sheet, but he was at the centre of modern physics as one of the pioneers of quantum field theory and quantum electrodynamics in the late 1920s and the 1930s. Today he is best known for his publications with Niels Bohr in 1933 and 1950 on measurability in quantum electrodynamics and as the fierce spokesman of Bohr's complementarity interpretation of quantum mechanics after the Second World War.² Rosenfeld was, however, exceptionally erudite and made detailed and significant contributions across the whole range of theoretical physics, such as quantum field theory, nuclear physics, statistical physics, and astrophysics. In 1956, he founded the journal Nuclear Physics. Besides, he reflected deeply on the history and philosophy of science and its social role. During his career he held chairs at Liège, Utrecht, Manchester, and Copenhagen. He received the Francqui Prize in 1949, which is given exclusively to Belgian scientists and scholars, but in spite of its national character bestows an honour comparable to the Nobel Prize. In addition to his contributions to physics, Rosenfeld played a salient role as Bohr's close collaborator as well as communicator of Bohr's quantum philosophy. In their collaboration Rosenfeld was in charge of the mathematical formulations of their theoretical considerations, but he also served as a sounding board for Bohr, that is, a critical mind on whom Bohr could try out his ideas. Such a sounding board was of crucial importance for Bohr's way of working…

The following sections are included:

• “You see, I was Belgian”

• Paris 1926–1927: Physics and Socialism

• Göttingen 1927–1929: The “Indeterminist” School

• Rosenfeld Finds his Style in Physics

• Two Approaches to Quantum Electrodynamics: Jordan versus Dirac

• Zurich 1929–1930: The Pauli–Heisenberg Quantum Field Theory

• Friendships

The following sections are included:

• The Institute for Theoretical Physics

• Assisting Bohr

• Crisis in Quantum Theory

• The “Small War”

• Dirac, “the Ugly Duckling”

• The Bohr–Rosenfeld paper

• The EPR paper

The following sections are included:

• Trotsky in Copenhagen

• Yvonne Cambresier

• The Promised Land

• Fascism and Nazism versus the Popular Front

• Battling for the Ideological Rights to Complementarity

• Bohr's French Connection

• Dreary Times

• Fission — A Question of Priority

The following sections are included:

• The Second World War

• Uhlenbeck's Successor

• Life in Holland under Nazi Occupation

• Heisenberg's Visit

• Hiding

The following sections are included:

• Dividing the World

• Science, Socialism, and Peace

• The End of the Popular Front

• The History of the Social Relations of Science

• Scientific Internationalism

• “The Soviet Crisis”

• The Maverick

• Anglo-American Science Policy and Anti-Communism

• Belgian Recognition

• Rosenfeld versus Bohr

The following sections are included:

• The Relationship between Science and Philosophy

• Rosenfeld versus Bohm

• “Strife about Complementarity”

• Thaw in East–West Relations

• Fock's Visit in Copenhagen

The following sections are included:

• Epilogue

• Bibliography

• Index