Arne Schirrmacher

Multiparameter R-matrices and their quantum groups

Multiparameter solutions of the Yang-Baxter equation associated with the groups of types A, B, C, D are given as generalizations of the well-known one-parameter solutions. The R-matrix approach to quantum groups is related to the algebraic one of Rheshitikhin (1990).

Generalized q‐exponentials related to orthogonal quantum groups and Fourier transformations of noncommutative spaces

Essential prerequisites for the study of q‐deformed physics are particle states in position and momentum representation. In order to relate x and p space by Fourier transformations the appropriate q‐exponential series related to orthogonal quantum symmetries is constructed. It turns out to be a new q‐special function giving rise to q‐plane wave solutions that transform with a noncommutative phase under translations.

Remarks on the Use of R-matrices

Examples for the application of the R-matrix formalism on problems related to GL(n) quantum groups are given. (1) The Yang-Baxter property of the R-matrix provides a simple means to replace the explicit use of the diamond lemma and thus eliminates lengthy calculations. (2) The Rmatrix description induces a pair of bicovariant differential calculi on the group. Reasons are given that these may be the only suitable ones.

Quantum Groups, Quantum Spacetime, and Dirac Equation

A simple modification of the Dirac algebra yields the q-deformed version corresponding to the framework of quantized Minkowski space. The method of deriving R-matrix relations for Minkowski coordinates, differentials, derivatives, and γ-matrices is explained. Taking a suitable conjugation structure on the derivatives and q-Dirac matrices allows for a q-analog of the Dirac equation that iterates to a Klein-Gordon equation. Its covariance is shown.

The structure of U q (sl(2, C))

The structure of the deformation Uq(sl(2, C)) is discussed. The comultiplication, all commutation relations, and a conjugation follow in a clear way form the simple SLq(2) structure. ‘Fundamental’ and spin representation are given.

Sounds and repercussions of war: mobilization, invention and conversion of First World War science in Britain, France and Germany

Abstract This paper examines the complex and evolving relationship between science and the military in the development of listening technologies by British, French and German combatants during the First World War to combat increasingly effective ballistics and artillery on the Western Front. Land-based combat changed from the visual to the aural with an increasing selection of audio-based surveillance technologies being made available, notably sound-ranging, in part to combat the physical limitations of the human ear in the battlefield space. The article concludes by analyzing how post-war physics responded to these developments in sound-based battlefield technologies.

Introduction: Communicating Science: National Approaches in Twentieth-Century Europe

In a recent book on The Publics of Science; Experts and Laymen Through History, Agustı́ Nieto-Galan introduced his subject of a (mostly Western) history of public science, covering the times from the Scientific Revolution to the twenty-first century, with reference to Sigmund Freud. In one of his essays of cultural critique, Freud had, so to speak, put culture itself on his couch, and this session also featured talk about science and technological application. Civilization and Its Discontents identified a factor of disillusionment in the progress of science and technology, which gave rise to “The Uneasiness in Culture” (the literal translation of the title of Freud’s German essay Das Unbehagen in der Kultur), and this uneasiness tainted a great deal of the happiness science and technology were intended to cultivate (Nieto-Galán 2011; Freud 1930). New technology and inventions like telephones, ocean liners, or drugs, Freud argued, were mostly remedies for negative developments technology had just created; for instance, without modern transportation people would stay close to each other and not need any telephone. (However, he did not address the issue of whether scientific knowledge itself may have provided some satisfaction.) The modern individual, as analyzed by Freud, was therefore constantly ill at ease with modern scientific and technological culture. Roughly the same line of thought is found by Nieto-Galán in Eric Hobsbawm’s The Age of Extremes: A History of the World, 1914–1991.1 In this book history is told through processes of failure, in particular of communism, capitalism, and nationalism, and in a chapter on the natural sciences he describes “a background glow of suspicion and fear” that accompanied progress in this sphere. Here it is the twentieth century which “was not at ease with the science which was its most extraordinary achievement, and on which it depended.” Four “feelings” dominated the perception of the modern world: “that science was incomprehensible; that both its practical and moral consequences were unpredictable . . . , that it underlined the helplessness of the individual,” and that “it was inherently dangerous” since it “interfered with the natural order of things”

Popular Science as Cultural Dispositif : On the German Way of Science Communication in the Twentieth Century

German twentieth-century history is characterized by stark changes in the political system and the momentous consequences of World Wars I and II. However, instead of uncovering specific kinds or periods of “Kaiserreich science,” “Weimar science,” or “Nazi science” together with their public manifestations and in such a way observing a narrow link between popular science and political orders, this paper tries to exhibit some remarkable stability and continuity in popular science on a longer scale. Thanks to the rich German history of scientific leadership in many fields, broad initiatives for science popularization, and a population and economy open to scientific progress, the media offered particularly rich popular science content, which was diversified for various audiences and interests. Closer consideration of the format, genre, quality, and quantity of popular science, and of the uses and value audiences attributed to it, along with their respective evolution, reveals infrastructures underpinning science communication. Rather than dealing with specific discourses, the conditions of science communication are at the center of this article. Therefore I focus on the institutions, rules, laws, and economies related to popular science, as well as on the philosophical, moral, and national propositions related to it, and also on the interactions among this ensemble of rather heterogeneous elements. This approach allows a machinery of popular scientific knowledge to be identified, in Foucauldian terms a dispositif , one which is of a particularly cultural nature.

Einleitung des Herausgebers

Philipp Lenard war Naturforscher, Nobelpreistrager und Nationalsozialist. Die letzten beiden Charakterisierungen sind die, in denen er bislang vornehmlich gesehen wurde. Darstellungen uber seine wissenschaftlichen Leistungen beschrankten ihn oft auf die Person eines Vorzeigewissenschaftlers des Kaiserreichs, dem wir bleibende und nicht in Frage stellbare Erkenntnisse zum Elektron, zum Atom oder zum Photoeffekt verdanken, und auf den eine Reihe wissenschaftlicher Instrumente und Begriffe zuruckgehen. Oder er erscheint als der ideologisch verirrte Vertreter einer durch Rasse determinierten Naturwissenschaft, der sich in Schriften und Kampagnen den Nationalsozialisten andiente und von ihnen ge- und verehrt wurde.

Philipp Lenard: Erinnerungen eines Naturforschers, der Kaiserreich, Judenherrschaft und Hitler erlebt hat

Meine Zeiten sind nicht da. Vielleicht kommen sie spater, wenn Wahrheit, Wirklichkeit und damit auch Naturforscher-Denken etwas gelten werden. Wahrheit wird zur Geltung kommen mussen unter den Menschen; denn sie ist das allein Geltende in der Natur, und die Menschen wurden sonst, trotz aller Technik, an Vertierung zu Grunde gehen, – was aber gegen die so offensichtliche Aufwartsentwicklung alles Lebenden ware, welche die Geologie in der Vorzeit an den Ausgrabungen in Geltung zeigt.