The modern corpuscular theory of radiation was born in 1905 when Einstein advanced his light quantum hypothesis; and the steps by which Einstein's hypothesis, after years of profound scepticism, was finally and fully vindicated by Arthur Compton's 1922 scattering experiments constitutes one of the most stimulating chapters in the history of recent physics. To begin to appreciate the complexity of this chapter, however, it is only necessary to emphasize an elementary but very significant point, namely, that while Einstein based his (...) arguments for quanta largely on the behaviour of high-frequency black body radiation or ultra-violet light, Compton experimented with X-rays. A modern physicist accustomed to picturing ultra-violet light and X-radiation as simply two adjacent regions in the electromagnetic spectrum might regard this distinction as hair-splitting. But who in 1905 was sure that X-rays and γ-rays are far more closely related to ultra-violet light than to α-particles, for example? This only became evident after years of painstaking research, so that moving without elaboration from Einstein's hypothesis to Compton's experiments automatically eliminates from consideration an important segment of history—a segment in which a major role was played by William Henry Bragg. (shrink)

This article addresses the historical problem of how it was possible for Lise Meitner and her nephew Otto Robert Frisch to arrive at their novel interpretation of nuclear fission at the end of 1938. To understand this requires an analysis of the origin and subsequent development of the liquid-drop model of the nucleus. We begin by discussing George Gamow’s conception of the liquid-drop model in 1928 and then explore its extension, particularly by Werner Heisenberg and Carl Friedrich von Weizsäcker, between (...) 1933 and 1936. We then examine the role played by the liquid-drop model in Niels Bohr’s theory of the compound nucleus between 1936 and 1938. We argue that these two stages in the development of the liquid-drop model focused on two distinctly different features of the model, its static and dynamic characteristics, which were employed to understand two distinctly different phenomena, nuclear mass defects and nuclear reactions and excitations. The liquid-drop model thus became embedded in two distinctly different scientific traditions. We conclude by showing how these two traditions merged in the minds of Meitner and Frisch, leading them to their interpretation of nuclear fission. (shrink)

Despite their shared interests, historians and philosophers of science collaborate poorly and generally lack firsthand experience in laboratories. This volume invents ways to develop their understanding of each other's goals and their common subject matter. Internatinally respected historians and philosophers of science clarify the distinct perspectives of each discipline and explore the types of interaction possible between them. By focusing on specific scientific problems, their papers make an excellent introduction to both historical and philosophical theories.

The ArgumentEinstein's mass-energy relationship was not confirmed experimentally until 1933 when Bainbridge showed that the Cockcroft-Walton experiment afforded a test of it. Earlier, however, it had been used constantly in the analysis of nuclear reactions, as can be seen in those involved in the determination of the mass of the neutron. Chadwick in 1932 was convinced that the neutron mass was about 1.0067 amu (atomic mass units), indicating that the neutron was a proton-electron compound, since that figure was less than (...) the sum of the proton and electron masses. Chadwick's value was challenged in 1933 by Lawrence, who proposed a much lower value of 1.0006 amu, and by Curie and Joliot, who proposed a much higher value of 1.011 amu.Much controversy ensued; eventually, Chadwick and Goldhaber showed in 1934 that the neutron mass was about 1.0080 amu, greater than the sum of the proton and electron masses, proving that the neutron was a new elementary particle (which could decay spontaneously), and providing conclusive experimental support for excluding electrons from the nucleus. These results remained unchanged with further refinements in the last decimal place, the entire pursuit of which provided still further vindication of Einstein's massenergy relationship. (shrink)

Kernphysiker in einer neuen Welt: Die Emigranten der dreißiger Jahre in Amerika. - Unter der großen Anzahl derjenigen, die durch Nationalsozialismus zur Emigration gezwungen wurden und zwischen 1933 und 1941 in die Vereinigten Staaten von Amerika einwanderten, befanden sich auch mehr als hundert Physiker, und unter ihnen einige der genialsten Kernphysiker der Welt. Die Physik in Amerika hatte damals den Status einer voll ausgereiften Wissenschaft erreicht, und so kam es zu einem bedeutsamen und facettenreichen Zusammenwirken zwischen den emigrierten und den (...) einheimischen Kernphysikern, zumal sie die verschiedenen Forschungsgebiete vertraten, die sich durch die Entdeckungen und Erfindungen des Jahres 1932 (Neutron, Deuterium, Positron, Cockcroft-Walton-Beschleuniger, Zyklotron) aufgetan hatten. Von besonderer Bedeutung Für die Konsolidierung und Entwicklung der gesamten Kernphysik war dabei die Veröffentlichung von drei Artikeln in den Reviews of Modern Physics von 1936 und 1937, bekannt als die „Bethe-Bibel”︁. Nach der Entdeckung der Kernspaltung von 1938 und dem Ausbruch des Krieges 1939 in Europa wirkte die Befürchtung, daß Hitler eine Atomwaffe erhalten könnte, als mächtige, Emigranten und Nicht-Emigranten gleichermaßen erfassende einigende Kraft unter den Atomphysikern in Amerika, und die meisten von ihnen stellten ihre Fähigkeiten in den Dienst der US-Regierung und arbeiteten am Manhatten-Projekt und an anderen militärischen Forschungsvorhaben mit. Bei Kriegsende waren die in den dreißiger Jahren emigrierten Kernphysiker wie so viele Flüchtlinge vor ihnen Amerikaner geworden, und keiner von ihnen kehrte in sein Geburtsland zurück.Among the large number of refugees from Nazism and Fascism entering the United States between 1933 and 1941 were more than 100 physicists, including some of the most gifted nuclear physicists in the world. By that time physics in America had come of age, and a remarkable and multifaceted symbiosis occurred between the émigré and native-born nuclear physicists as they pursued the many avenues of research opened up by the discoveries and inventions of 1932 (neutron, deuterium, positron, Cockcroft-Walton accelerator, cyclotron). Of particular importance for the consolidation and development of the entire field of nuclear physics was the publication in 1936–37 of the three articles in the Revieus of Modern Physics known as the „Bethe Bible”︁. With the discovery of nuclear fission in 1938 and the outbreak of war in Europe in 1939, the fear that a nuclear weapon might fall into Hitler's hands served as a powerful unifying force among nuclear physicists in Amerika, émigrés and non-émigrés alike, and most placed their talents in the service of the United States Government working on the Manhattan Project and other wartime research. By the end of the war, like so many refugees before them, the émigré nuclear physicists of the 1930s had become Americans, and not one of them returned to the country of his birth. (shrink)

Introduction: to the student -- Ethics and Christian ethics -- An overview of ethics -- Definitions -- Subject matter -- Assumptions -- Cautions -- Alternatives to Christian ethics -- Religious systems -- Judaism -- Islam -- Hinduism -- Buddhism -- Humanism -- Objectivism -- Behaviorism -- Alternatives within Christian ethics -- Obedience to external authority -- In Roman Catholicism -- In Protestantism -- Responsibility for personal decisions -- What am I to do? -- What am I to be? -- Transforming (...) society -- Reinhold Neibuhr's "impossible possibility" -- Paul Ramsey's "obedient love" -- James Gustafson's "theocentric ethics" -- Liberation theology -- Ethics and the Christian faith -- Sources of guidance -- The Bible -- The Christian community -- The nature of the church -- The function of the church -- The Christian in the church -- Personal experience -- The use of the mind -- The prompting of the conscience -- The leadership of the spirit -- Biblical ethics -- The Hebrew Scripture -- General characteristics of Hebrew morality -- The law, the prophets, and the writings -- Jesus and the Gospels -- Jesus and Judaism -- Characteristics of Jesus's ethical teachings -- Basic concepts in Jesus's ethical teachings -- The example of Jesus -- The ethical teachings of Paul -- Theology and ethics -- An ethic of responsible freedom -- An ethic of love -- An ethic of a new life -- Faith working through love -- Theological premises -- Beliefs about God -- Beliefs about humankind -- Beliefs about history -- Faith -- Faith and salvation -- Life in the Christian community -- The instruction of Scripture -- Worship and morality -- Love (agape) -- The nature of love -- The source of love -- The demands of love -- The relationship between love and justice -- Decision -- Christian ethics and contemporary issues -- Human sexuality and the marriage relationship -- The current scene -- A Christian interpretation of sexuality -- A theological perspective -- Questions about the relationship -- A Christian interpretation of marriage -- Homosexuality and the Christian faith -- Contemporary social perspective -- A biblical perspective -- Varying Christian interpretations -- Homosexuality and the Christian way of live. (shrink)

ArgumentThis essay seeks to identify the cultural significance of Goethe's scientific writings. He reformulates, in the light of his own concrete experience, “crucial turning-points” in the history of science – key ideas, the historical understanding of which is vital to present understanding – thus situating his own scientific work at the bi-polar center of the Western scientific tradition, conceived as the dramatic interplay over centuries of two opposing modes of thought. For in his experimentation he recaptures the glimpse of living (...) form gained in aesthetic perception, from which such inherited theoretical positions are ultimately derived. At each stage of this process, imagination, in its aesthetic modality, is essential, for it alone reveals the world as it truly is. The literary quality of his writings on nature, as on culture, reveals Goethe's stylistic achievement in devising a medium in which the insights gained in contemplation may be so transmitted as to make a similar, imaginative, appeal to his reader – re-enacting the abstract-concrete equilibrium characterizing all aesthetic experience. Matching his style to the subtle, delicate, connectedness of Nature, Goethe recreates the delights of participating in natural creativity. His Janus-faced, scientific-literary, style illustrates “binary synthesis,” the principle that unites Goethe's science with his art.Beauty is the normal state.There can be no such thing as an eclectic philosophy, but there can be eclectic philosophers. But an eclectic is anyone who, from whatever exists and is happening round about, appropriates the things he or she finds congenial to her or his nature; and this context validly includes all that can be called culture and progress in a theoretical and practical sense. It follows that two eclectic philosophers could turn into the greatest opponents if they are antagonistic to one another, each picking out whatever suits him or her in every traditional system of philosophy. (shrink)

Occasional Papers in Cassirer and Cultural-Theory Studies presented at the University of Glasgow's Centre for Intercultural Studies. Given the growing disenchantment, on all sides, with the 'high theory' of the 1970s and 1980s, and with the dominant master-trope of literary and cultural reflexion of the 1980s and 1990s, the extended metaphor or 'allegory', this volume offers a timely re-examination of what, according to Goethe, is a deeper mode of understanding the symbol. Via the life-long preoccupation of Ernst Cassirer with the (...) problems of 'symbolic form', as he christened it, the papers collected here try to come to terms with the thinking of Goethe and Schiller on the symbol, and on related issues. Taken together, they attempt to elucidate the filiation of German classicism down through the nineteenth century to the present, in the belief that some of Cassirer's ideas have fed, often unacknowledged, into the mainstream of contemporary cultural theory, and that the rigour of his thought can help clear up much of the confusion in that 'theory'. (shrink)

The famous story of the choice of Hercules became one frequently depicted in Western art and, as Ernst Panofsky showed, the various treatments of this theme demonstrate the significance of cultural continuity through the centuries. At the same time, the motif of Hercules and his choice presents us with a challenge to current theoretical approaches to culture. We can either take the easy path and accept the current hermeneutic orthodoxies of popular cultural studies, or we can choose a harder but, (...) ultimately, more rewarding path: the philosophy of culture articulated by Ernst Cassirer. This volume brings together a collection of papers which reflects the broad sweep, both historical and theoretical, of Cassirer's philosophy of symbolic forms. They range from language-theory to myth and religion; and all are set, with varying degrees of emphasis, in a comparative context. (shrink)