Paul Ehrenfest’s Rough Road to Leiden: A Physicist’s Search for a Position, 1904–1912

Paul Ehrenfest (1880–1933) received his Ph.D. degree at the University of Vienna in 1904 and moved with his wife and young daughter to St. Petersburg in 1907, where he remained until he succeeded Hendrik Antoon Lorentz (1853–1928) in the chair of theoretical physics at the University of Leiden in 1912. Drawing upon Ehrenfest’s correspondence of the period, we first examine Ehrenfest’s difficult and insecure years in St. Petersburg and then discuss his unsuccessful attempts to obtain a position elsewhere before he was appointed as Lorentz’s successor in Leiden. Pim Huijnen is writing a doctoral dissertation in history; the present paper is based upon his Master’s Thesis, “‘Die Grenze des Pathologischen’: Het leven van fysicus Paul Ehrenfest, 1904–1912,” University of Groningen, 2003. A.J.Kox is Pieter Zeeman Professor of History of Physics at the University of Amsterdam.     

Between Autonomy and Accommodation:The German Physical Society during the Third Reich

I first sketch the history of the German Physical Society (Deutsche Physikalische Gesellschaft,DPG) from its founding by six young Berlin scientists as the Physical Society of Berlin (Physikalische Gesellschaft zu Berlin) in 1845, through its renaming as the DPG in 1899 and its rise to prominence by the beginning of the 1930s. I then turn to the history of the DPG during the Third Reich, which can be divided into two periods, from the transfer of power in Germany to the Nazis in 1933 to 1940, and from 1941 to 1945. During the first period, Johannes Stark (1874–1957), one of the leaders of the “German Physics” (Deutsche Physik) movement, attempted to gain election as the Chairman of the DPG in September 1933 but was repulsed. A period of relative autonomy of the DPG from Nazi ideology and policies ensued, which gradually was transformed into one of accommodation, until at the end of the 1938, Peter Debye (1884–1966), then Chairman of the DPG, bowed to governmental demands and Nazi activists in the DPG, introduced Nazi principles, and strongly advised the Jewish members of the DPG to withdraw from it. Debye left Germany in early 1940, and after a transitional period in which Jonathan Zenneck (1871–1959) served as Acting Chairman, Carl Ramsauer (1879–1955) was elected Chairman of the DPG in December 1940, thus opening the second period, the Ramsauer era, which lasted from 1941 until the end of the war in 1945. Ramsauer oversaw the self-coordination (Selbstgleichschaltung) of the DPG to the Nazi regime, and as an industrial physicist he led the DPG to establish ever more alliances with powerful figures in the military-industrial complex of Nazi Germany, which worked to the advantage both of Ramsauer and the DPG and to that of the Nazi regime during the course of the war. Finally, as the military defeat of Germany loomed, Ramsauer took steps aimed at insuring the survival of German physics in the postwar period. After the war, he masked the wartime activities of himself and the DPG, thereby contributing to the postwar conspiracy of silence or minimization of the Nazi past in Germany. Dieter Hoffmann is a research scholar at the Max Planck Institute for the History of Science and a professor at Humboldt University in Berlin.     

Richard Gans: The First Quantum Physicist in Latin America

Richard Gans (1880–1954) was appointed Professor of Physics and Director of the Institute of Physics of the National University of La Plata,Argentina, in 1912 and published a series of papers on quantum physics between 1915 and 1918 that marked him as the first quantum physicist in Latin America. I set Gans’s work within the context of his education and career in Germany prior to 1912 and his life and work in Argentina until 1925, as well as the foundation of the Institute of Physics of the National University of La Plata in 1906–1909 and its subsequent development by Emil Bose (1874–1911). I conclude by commenting on Gans’s life after he returned to Germany in 1925 and then immigrated once again to Argentina in 1947.     

In Memoriam

In 1905 Lord Kelvin (1824–1907) was awarded the second John Fritz Medal for a lifetime of outstanding achievements in science and technology. I sketch Kelvin’s life, education, and work in thermodynamics, electrical technology, and instrumentation, and his role in the laying of the Atlantic cable. I then turn to Kelvin’s four visits to America, in 1876 on the centenary of the Declaration of Independence of the United States of America; in 1884 when he gave his famous Baltimore Lectures at The Johns Hopkins University; in 1897 when he visited Niagara Falls for the third time and advised George Westinghouse (1846–1914) on how to develop its enormous water power for the generation of electricity; and in 1902 when he advised George Eastman (1854–1932) on the development of the photographic industry. Written in connection with the Kelvin Centenary Year 2007; see “Celebrating the Life of Lord Kelvin,” University of Glasgow News Review No. 11 (2007), 4. Matthew Trainer: Matthew Trainer received his M.Phil. degree in physical sciences at the University of Edinburgh in 1980 and currently is a laboratory instructor at the University of Glasgow where his research focuses in part on the life and work of Lord Kelvin.     

In Appreciation¶A Lifetime of Connections: Otto Herbert Schmitt, 1913 - 1998

Otto H. Schmitt was born in St. Louis, Missouri, in 1913. As a youth, he displayed an affinity for electrical engineering but also pursued a wide range of other interests. He applied his multi-disciplinary talents as an undergraduate and graduate student at Washington University, where he worked in three departments: physics, zoology, and mathematics. For his doctoral research, Schmitt designed and built an electronic device to mimic the propagation of action potentials along nerve fibers. His most famous invention, now called the Schmitt trigger, arose from this early research. Schmitt spent most of his career at the University of Minnesota, where he did pioneering work in biophysics and bioengineering. He also worked at national and international levels to place biophysics and bioengineering on sound institutional footings. His years at Minnesota were interrupted by World War II. During that conflict - and the initial months of the Cold War to follow - Schmitt carried out defense-related research at the Airborne Instruments Laboratory in New York. Toward the end of his career at Minnesota, Schmitt coined the term biomimetics. He died in 1998. RID="*" ID="*"Jon M. Harkness received his Ph.D. degree in the history of science from the University of Wisconsin in 1996. During the spring of 2002, he is an adjunct assistant professor of the history of medicine at the University of Minnesota.     

Ettore Majorana’s Forgotten Publication on the Thomas-Fermi Model

We analyze the forgotten communication of Ettore Majorana (1906–1938?) on the Thomas-Fermi statistical model of the atom, which he presented on December 29, 1928, during the XXII General Meeting of the Italian Physical Society in Rome, and which was published in Il Nuovo Cimento, the Society’s journal, in 1929. His communication was not mentioned subsequently in any of the numerous publications of Enrico Fermi (1901–1954) and his group in Rome, nor in any of the later accounts of Majorana’s life and work. We place Majorana’s contribution within the context of contemporary research on the subject, point out its influence on the final formulation of the Thomas-Fermi statistical model by Fermi and Edoardo Amaldi (1908–1989) in 1934, and discuss Majorana’s other scientific contributions before his mysterious disappearance in 1938. Francesco Guerra is Professor of Theoretical Physics in the Department of Physics at the University of Rome “La Sapienza.” His main fields of research are quantum-field theory, statistical mechanics of complex systems, and the history of nuclear physics. Nadia Robotti is Professor of History of Physics in the Department of Physics at the University of Genoa. Her main fields of research are the history of atomic physics, quantum mechanics, and nuclear physics.     

Gerson Goldhaber: A Life in Science

I draw on my interviews in 2005–2007 with Gerson Goldhaber (1924–2010), his wife Judith, and his colleagues at Lawrence Berkeley National Laboratory. I discuss his childhood, early education, marriage to his first wife Sulamith (1923–1965), and his further education at the Hebrew University in Jerusalem (1942–1947) and his doctoral research at University of Wisconsin at Madison (1947–1950). He then was appointed to an instructorship in physics at Columbia University (1950–1953) before accepting a position in the physics department at the University of California at Berkeley and the Radiation Laboratory (later the Lawrence Berkeley Laboratory, today the Lawrence Berkeley National Laboratory), where he remained for the rest of his life. He made fundamental contributions to physics, including to the discovery of the antiproton in 1955, the GGLP effect in 1960, the psi particle in 1974, and charmed mesons in 1977, and to cosmology, including the discovery of the accelerating universe and dark energy in 1998. Beginning in the late 1960s, he also took up art, and he and his second wife Judith, whom he married in 1969, later collaborated in illustrating and writing two popular books. Goldhaber died in Berkeley, California, on July 19, 2010, at the age of 86.     

A Physicist for All Seasons: Part I

The first part of this interview covers Frank Oppenheimer’s childhood, family background, and early education in New York City; his deep lifelong bond to his older brother Robert; his undergraduate years at Johns Hopkins University (1930–1933); his stays at the Cavendish Laboratory in Cambridge, England, and at the University of Florence, Italy (1933–1935); his graduate studies at the California Institute of Technology (1935–1939); his postdoctoral assistantship at Stanford University (1939–1941); and the frequent summers he spent in New Mexico with his brother, family, and friends.     

The Norwegian and the Englishman

I sketch the lives and work of the Norwegian physicist Kristian Birkeland (1867–1917) and the English mathematician Sydney Chapman (1888–1970), focusing particularly on Chapman’s controversy with Birkeland over the origin and development of auroras, a controversy that Chapman conducted with Birkeland for more than fifty years after Birkeland’s death. Sidney Borowitz is Professor Emeritus of Physics at New York University.     

Harry Lehmann

   Harry Lehmann was born in 1924 at Güstrow, Mecklenburg. After graduation from school in Rostock, the German army drafted him in 1942 for service in North Africa, where he was taken prisoner of war by the American forces. He spent three years in a prison camp in the United States; there he had the opportunity to study on his own, and to prepare for the university. When he was released in 1946, he soon returned to his parents in Rostock and began to study physics, first at the University of Rostock, then at the Humboldt University in East Berlin, obtaining his diploma with a thesis on experimental physics. In 1949 he became assistant of Friedrich Hund at the University of Jena, where he wrote his doctoral dissertation on classical electrodynamics. When Hund moved to the University of Frankfurt, Lehmann served at Jena as acting professor, until Hund was replaced. In the fall of 1952, Heisenberg offered Lehmann a position at the Max Planck Institute for Physics in G?ttingen. There he joined an active group of young theorists from Germany and abroad who had come to collaborate with Heisenberg. After his initial stay, he requested permission to extend his visit; but the authorities of the former German Democratic Republic never responded, and so Harry Lehmann remained in the west. As a result it was not until 1976 that he could once again visit his parents in Rostock. A main topic of discussion in Heisenberg's institute was the method of renormalization, that had been developed in the United States and Japan right after the war. This technique made it possible to compute measurable quantities of quantum electrodynamics, and to compare them with experiments, even though divergent integrals entered intermediate stages of the calculations. Despite the enormous success of renormalization theory, made evident by the high-precision agreement between theory and experiment, many physicists of the older generation in Europe remained skeptical and were convinced that the infinities indicated a serious deficiency of quantum field theory. Dirac, for instance, called renormalization theory “a sin against theoretical physics”. On the other hand the younger theoretical physicists were quite enthusiastic. They considered it a challenge to reformulate the theory in such a way that renormalization infinities never occur, either in the formulation of the principles, or in the calculation of observable quantities. Harry Lehmann's publication on the properties of propagators [1] was an early decisive step in this direction. From minimal assumptions he derived the main properties of propagators, and expressed the constants of renormalization by integrals over finite quantities, even though those quantities diverged in perturbation theory. He carried out a large part of his pioneering work in the 1950's, in collaboration with Kurt Symanzik and Wolfhart Zimmermann. The shorthand designation LSZ is familiar to all elementary particle physicists up to this day. The LSZ-formalism and the Lehmann representation are among the most important basic tools of the theory of elementary particles [2]. An important application of this technique in scattering theory provides the relation between scattering amplitudes and time ordered correlation functions. These were derived as an immediate consequence of the asymptotic behavior of field operators in the distant past and future. In 1955 Harry Lehmann left Heisenberg's institute to visit Copenhagen as a member of the CERN Study Group, and in 1956 he accepted a professorship at the University of Hamburg to become the successor to Wilhelm Lenz. He founded the theoretical elementary particle physics group, and for thirty years, his strong personality determined the character of the II. Institut für Theoretische Physik at Hamburg University. He became Professor Emeritus in 1986. He also advised the German Electron Synchrotron laboratory DESY and helped start its theory group by persuading Kurt Symanzik to return there from New York. Many young scientists were strongly influenced by his personality, by his style of discussion in seminars, by the conciseness of his insightful contributions to research, and by his views on physics in general. Harry Lehmann's interest in the theory of dispersion relations led to the beginning of his close collaboration with Res Jost. In the case of equal mass scattering Jost and Lehmann found a representation for matrix elements of the commutator of two field operators between energy-momentum eigenstates [3]. This representation was extended by Dyson to the general case of unequal masses [4]. On the basis of the Dyson representation, Lehmann derived dispersion relations and other analytic properties of the scattering amplitudes as a consequence of locality, relativistic invariance and conditions on the particle spectrum [5]. These results are also valid for composite particles despite their internal structure, since only general properties are used in the derivation which are independent of the dynamics of the system. Dispersion relations, therefore, provide an experimental test for the principles of local quantum field theory. Harry Lehmann remained active in research until the end of his life. He directed several NATO Advanced Study Institutes in Cargèse (France). With K. Pohlmeyer he worked on field theories with non-polynomial Lagrangians. During his last years he investigated symmetry breaking effects for the quark mass spectrum together with T. T. Wu. Harry Lehmann's scientific merits were recognized in many ways. He received the Max Planck medal of the German Physical Society 1967 and he was made a Chevalier de la Legion d'Honneur on December 31, 1969. He was honoured in 1997 by the Dannie Heineman Prize of the American Physical Society and the American Institute of Physics. Harry Lehmann was an excellent speaker with the remarkable ability to communicate involved and difficult subjects understandably. We remember him gratefully, in friendship, and with esteem for his scientific work.     

In Memoriam

I sketch the rich life and multifaceted work of Philip Morrison (1915–2005), from his early life in Pittsburgh, Pennsylvania, and higher education at the Carnegie Institute of Technology and the University of California at Berkeley, to his contributions to the Manhattan Project, his research at Cornell University and the Massachusetts Institute of Technology after the war, his subsequent political activity on behalf of nuclear disarmament, his role in the search for extraterrestrial intelligence, and his enormous influence as an educator, public speaker, and writer. A.P. French is Professor of Physics, Emeritus, at the Massachusetts Institute of Technology.     

In Appreciation

Leslie Foldy’s diminutive stature and modest demeanor gave little clue to the powerful intellect responsible for several significant advances in theoretical physics.Two were particularly important. His 1945 theory of the multiple scattering of waves laid out the fundamentals that most modern theories have followed (and sometimes rediscovered), while his work with Siegfried Wouthuysen on the nonrelativistic limit of the Dirac equation opened the way to a wealth of valuable insights. In this article we recall some of the milestones along Foldy’s path through a life in physics. Some of the anecdotes we report here were related to one of the authors (PLT) just before an event in 2000 celebrating Foldy’s 80th birthday, while others were told to us over the course of the nearly forty years during which we were colleagues. Still others were uncovered during the course of WJF’s research for his book, Physics at a Research University: Case Western Reserve 1830–1990 (Cleveland: Case Western Reserve University, 2006). Other details were provided by Foldy’s widow, Roma. Philip L. Taylor is the Perkins Professor of Physics and Professor of Macromolecular Science and Engineering at Case Western Reserve University. William J. Fickinger is Professor Emeritus of Physics at Case Western Reserve University.     

Berkeley and Its Physics Heritage

I first sketch the settlement of Berkeley, California, the founding of the University of California at Berkeley, and the origin of its Department of Physics. I then discuss the pivotal role that Ernest O. Lawrence (1901–1958) and his invention and subsequent development of the cyclotron played in physics at Berkeley after his arrival there in 1928 through the Second World War and beyond. I close by commenting on the Lawrence Hall of Science, the educational center and science museum conceived as a living memorial to Lawrence.     

Quirino Majorana’s Experiments on the Speed of Light and Gravitational Absorption

Quirino Majorana (1871–1957) was an outstanding Italian experimental physicist who investigated a wide range of phenomena during his long career in Rome,Turin, and Bologna. We focus on his experiments in Turin during 1916–1921 and in Bologna during 1921–1934 to test the validity of Albert Einstein’s postulate on the constancy of the speed of light and to detect gravitational absorption. These experiments required extraordinary skill, patience, and dedication, and all of them confirmed Einstein’s postulate and Isaac Newton’s law of universal gravitation to high precision. Had they not done so, Majorana’s fame among historians and physicists no doubt would be much greater than it is today. Giorgio Dragoni is Professor of History of Physics at the University of Bologna. Giulio Maltese is a Roman member of the Italian Society for the History of Physics and Astronomy. Luisa Atti is a Bolognese member of the Association for the Teaching of Physics.     

Paul Ehrenfest, Niels Bohr, and Albert Einstein: Colleagues and Friends

In May 1918 Paul Ehrenfest received a monograph from Niels Bohr in which Bohr had used Ehrenfest’s adiabatic principle as an essential assumption for understanding atomic structure. Ehrenfest responded by inviting Bohr, whom he had never met, to give a talk at a meeting in Leiden in late April 1919, which Bohr accepted; he lived with Ehrenfest, his mathematician wife Tatyana, and their young family for two weeks. Albert Einstein was unable to attend this meeting, but in October 1919 he visited his old friend Ehrenfest and his family in Leiden, where Ehrenfest told him how much he had enjoyed and profited from Bohr’s visit. Einstein first met Bohr when Bohr gave a lecture in Berlin at the end of April 1920, and the two immediately proclaimed unbounded admiration for each other as physicists and as human beings. Ehrenfest hoped that he and they would meet at the Third Solvay Conference in Brussels in early April 1921, but his hope was unfulfilled. Einstein, the only physicist from Germany who was invited to it in this bitter postwar atmosphere, decided instead to accompany Chaim Weizmann on a trip to the United States to help raise money for the new Hebrew University in Jerusalem. Bohr became so overworked with the planning and construction of his new Institute for Theoretical Physics in Copenhagen that he could only draft the first part of his Solvay report and ask Ehrenfest to present it, which Ehrenfest agreed to do following the presentation of his own report. After recovering his strength, Bohr invited Ehrenfest to give a lecture in Copenhagen that fall, and Ehrenfest, battling his deep-seated self-doubts, spent three weeks in Copenhagen in December 1921 accompanied by his daughter Tanya and her future husband, the two Ehrenfests staying with the Bohrs in their apartment in Bohr’s new Institute for Theoretical Physics. Immediately after leaving Copenhagen, Ehrenfest wrote to Einstein, telling him once again that Bohr was a prodigious physicist, and again expressing the hope that he soon would see both of them in Leiden.     

A Conversation with Franco Rasetti

Along with Enrico Fermi, Franco Rasetti played a key role in the rebirth of Italian physics in the 1920s and 1930s. In this interview he talks about his experiments at Caltech on the Raman effect in 1928–1929, mountain climbing, his passion for bugs, fossils, and flowers, and doing physics in Florence, Rome, Berlin-Dahlem, and Quebec. Rasetti also reminisces about the Rome school of mathematics and other scientists he has known and worked with in Europe and in North America, including Robert and Glenn Millikan, Lise Meitner, and O. M. Corbino.     

Henri Victor Regnault: Experimentalist of the Science of Heat

Henri Victor Regnault (1810–1878) was one of the most famous French experimental scientists of the nineteenth century. After studying and carrying out research at the école Polytechnique and the école des Mines in Paris, he was elected to the Paris Académie des Sciences in 1840 and was appointed Professor of Experimental Physics at the Collège de France in 1841. His initial researches were in chemistry, but his careful experimental investigations of the law of the specific heat of solids that Pierre Louis Dulong (1785–1838) and Alexis Thérèse Petit (1791–1820) proposed in 1818 opened the door to his transition to physics and to his pioneering experimental researches on various thermodynamic properties of liquids and gases. I focus particularly on his investigations on the expansion, compressibility, vapor pressure, and speed of sound in gases. He also made important contributions to the new art of photography and to the ceramic industry as director of the Sèvres factory, at a time when his personal life was filled with tragedy. While his experimental work was acclaimed by his contemporaries, it has been largely neglected by scientists and historians today.     

The Life and Work of Joseph Plateau: Father of Film and Discoverer of Surface Tension

In 1835 Joseph Plateau (1801?C1883) was appointed Professor of Physics and Applied Physics at Ghent University, Belgium. By then he was well known for his groundbreaking work on the aftereffect of light on the human retina, and he would go on to become the first person to produce moving images, for which he is considered to be the Father of Film. His greatest scientific achievement, however, was his discovery of surface tension.     

Bruno Rossi and the Racial Laws of Fascist Italy

Bruno Rossi (1905–1993), one of the giants of 20th-century physics, was a pioneer in cosmic-ray physics and virtually every other aspect of high-energy astrophysics. His scientific career began at the University of Florence in 1928 and continued at the University of Padua until 1938, when the Fascist anti-Semitic racial laws were passed in Italy. He was dismissed from his professorship and was forced to emigrate, as described in unpublished letters and documents that display the international character of physics and physicists. His young bride Nora Lombroso, his love of physics, and the solidarity of the physics community gave him the courage to begin a new life in Copenhagen, Manchester, and in the New World at the University of Chicago, Cornell University, Los Alamos, and after the Second World War at the Massachusetts Institute of Technology where he became the center of a worldwide research network.