The gauge-invariant relativistic wave mechanics corresponds to relativistic magneto-hydrodynamics according to Planck's version of the correspondence principle.

A dual form of the general relativistic and covariant generalization of the first vorticity theorem of Helmholtz is proven. This dual form is the generalization of Boltzmann's formulation of the Helmholtz theorem.

The article gives an overview on Albert Einstein's activity in relation to geophysics. Various aspects of his fundamental investigations and their significance for geophysical research are discussed.

The general theory of relativity gives an absolutely covariant formulation of Helmholtz's laws of vorticity which is valid in arbitrary reference systems. For small relative velocities ui, (with ui,u′≪ε2) these generally covariant laws deliver Helmholtz's first law for a vorticity ωi in a rigidly rotating references system $\frac{d}{{dt}}(\omega _i - \Omega _\iota ) = (\omega ^l - \Omega ^l )u_{l,i} $ with the angular velocity Ω of the rotation.

The relativistic formulation of Hide's “magnetic analogue” of Ertel's potential vorticity theorem is Dirac's “new classical theory of electrons”.

The covariant and relativistic generalization of the Helmholtz integral vorticity theorems and Thomson's circulation theorem are derived.

The general relativistic and covariant differential form of Helmholtz's first vorticity theorem is presented. We prove in relation with it an invariant kinematic identity which is the generalisation of the Helmholtz theorem for general continua.

Written in the 1960s, TRUTH AND METHOD is Gadamer's magnum opus.

It is a remarkable fact that Hilbert's programmatic papers from the 1920s still shape, almost exclusively, the standard contemporary perspective of his views concerning (the foundations of) mathematics; even his own, quite different work on the foundations of geometry and arithmetic from the late 1890s is often understood from that vantage point. My essay pursues one main goal, namely, to contrast Hilbert's formal axiomatic method from the early 1920s with his existential axiomatic approach from the 1890s. Such a contrast illuminates (...) the circuitous beginnings of the finitist consistency program and connects the complex emergence of existential axiomatics with transformations in mathematics and philosophy during the 19th century; the sheer complexity and methodological difficulties of the latter development are partially reflected in the well known, but not well understood correspondence between Frege and Hilbert. Taking seriously the goal of formalizing mathematics in an effective logical framework leads also to contemporary tasks, not just historical and systematic insights; those are briefly described as “one direction” for fascinating work. (shrink)

Der große jüdische Religionsphilosoph Martin Buber (1878-1965) war auch als Pädagoge und Andragoge eine bedeutende Persönlichkeit in der Geistesgeschichte des 20. Jahrhunderts. 1924 war er Gast der damals von Wilhelm Flitner geleiteten Volkshochschule Jena. An seinen dortigen Begegnungen lässt sich exemplarisch das Selbstverständnis und die Methodik Bubers eindrucksvoll sichtbar machen. Von der Analyse der Jenaer Konstellation geht dieser Sammelband aus, führt aber darüber hinaus zu Bubers weitgespannten Wirkungsfeldern, wobei auch bisher unerschlossenes Archivmaterial ausgewertet wird. Vertieft werden neben pädagogisch-andragogischen auch religiöse, (...) sprachanalytische und politisch-ethische Aspekte, dargestellt u.a. auch über biographische Bezüge zu herausragenden Zeitgenossen wie Leo Boeck und Dag Hammarskjöld. Darüberhinaus enthält der Band auch Unveröffentlichtes aus Bubers Feder, so eine Auswahl aus seinem Briefwechsel mit Wilhelm Flitner sowie einen systematischen Grundlagenartikel zur Erwachsenenbildung. (shrink)

Émile Durkheim remains one of the most controversial, and deeply misunderstood, classics of social theory. His work differs from the dominant version of sociology that has essentially accepted the modernist self-description of contemporary societies; and it contradicts the individualism that has come to dominate the social sciences. For everybody who is interested in constructing theoretical alternatives to this individualism, Durkheim's sociology can be a useful inspiration - not only because of the solutions it suggests, but already because of the questions (...) it asks. Making use of the theoretical possibilities offered by the Durkheimian tradition, however, requires going beyond the familiar appropriations. The Oxford Handbook of Émile Durkheim takes stock of the different recent debates on Durkheimian sociology, and makes them accessible to a wide audience spanning various disciplines; this includes crucial debates that, due to language barriers, are not easily accessible for an English-reading public. The handbook's chapters elucidate the controversial key concepts of Durkheimian sociology; situate them within the contemporary political and theoretical debates they were originally responding to; offer surveys of empirical research that uses Durkheimian concepts (on topics that were already central for Durkheim's own work as well as on topics that Durkheim hardly touched upon), thus demonstrating the possibilities of a Durkheimian sociology; bring out the divergent, and competing, ways in which Durkheim's ideas have been appropriated and reformulated within more recent theoretical developments in the social sciences. In doing so, this volume is an important resource for all scholars and students looking to understand Durkheimian sociology. (shrink)

Plus que tout autre philosophe antique, Plotin semble mettre ses interprètes au défi de décrypter le fond de sa pensée. En effet, elle a l’air d’un système, mais le lecteur des Ennéades ne se voit pas livrer les structures conceptuelles principales qui doivent en assurer la cohérence. Emilsson s’est proposé le décryptage de certaines structures qui ont la fonction de principe conceptuel soit tout à fait général soit spécifique pour un champ thématique déterminé. Après avoir proposé une étude...

Religious sects and their practices have become highly topical in the recent past in Germany. The call for criminal sanctions in order to tackle actual or presumed misconduct is becoming louder and louder. The author, a criminal law professor, analyses the present discussion and puts it into a constitutional law perspective. Any civil society that aims to optimise the scope of the personal freedoms of its members must withstand the temptation of creating a special regime of criminal law rules just (...) to combat religious sects and their practices. Criminal law has tobe applied uniformly in the whole society. Therfore, criminal sanctions can only be handed out, when practices infringe intolerably with the individual' s rights protected by the law. (shrink)

Users have adopted a wide range of digital technologies into their communication repertoire. It remains unclear why they adopt multiple forms of communication instead of substituting one medium for another. It also raises the question: What type of need does each of these media fulfill? In the present article, the authors conduct comparative work that examines the gratifications obtained from Facebook with those from instant messaging. This comparison between media allows one to draw conclusions about how different social media fulfill (...) user needs. Data were collected from undergraduate students through a multimethod study based on 77 surveys and 21 interviews. A factor analysis of gratifications obtained from Facebook revealed six key dimensions: pastime, affection, fashion, share problems, sociability, and social information. Comparative analysis showed that Facebook is about having fun and knowing about the social activities occurring in one’s social network, whereas instant messaging is geared more toward relationship maintenance and development. The authors discuss differences in the two technologies and outline a framework based on uses and gratifications theory as to why young people integrate numerous media into their communication habits. (shrink)

The Hygiene Hypothesis has been recognized as an important cornerstone to explain the sudden increase in the prevalence of asthma and allergic diseases in modernized culture. The recent epidemic of allergic diseases is in contrast with the gradual implementation of Homo sapiens sapiens to the present-day forms of civilization. This civilization forms a gradual process with cumulative effects on the human immune system, which co-developed with parasitic and commensal Helminths. The clinical manifestation of this epidemic, however, became only visible in (...) the second half of the twentieth century. In order to explain these clinical effects in terms of the underlying IgE-mediated reactions to innocuous environmental antigens, the low biodiversity of antigens in the domestic environment plays a pivotal role. The skewing of antigen exposure as a cumulative effect of reducing biodiversity in the immediate human environment as well as in changing food habits, provides a sufficient and parsimonious explanation for the rise in allergic diseases in a highly developed and helminth-free modernized culture. Socio-economic tendencies that incline towards a further reduction of environmental biodiversity may provide serious concern for future health. This article explains that the “Hygiene Hypothesis”, the “Old Friends Hypothesis”, and the “Skewed Antigen Exposure Hypothesis” are required to more fully explain the rise of allergy in modern societies. (shrink)

In Hume’s Of Miracles the person movecl by faith is put in a dilemma between faith and reason. Can one resolve this dilemma as a compleat Humean? The answer is yes. Within the Humean context different approaches can be developed ta overcome Hume’s dilemma. One uses Hume’s theory of utility to defend the belief in the afterlife. The other requires Hume to place faith on a par with beauty and therefore among the passions to which reason must be a slave. (...) Historically there was at least one compleat Humean who was also moved by faith --- Johann Georg Hamann [1730- 1788]. (shrink)

What are networked organizations? The focus of discussions of the networked organization has been on the boundary-spanning nature of these new organizational structures. Yet, the role of the group in these networked organizations has remained unclear. Furthermore, little is known about how computer-mediated communication is used to bridge group and organizational boundaries. In particular, the role of new media in the context of existing communication patterns has received little attention. We examine how employees at a high-tech company, referred to as (...) KME, communicate with members of the work group, other colleagues in the organization, and colleagues outside the organization to better understand their boundary-spanning communications. (shrink)

One of the leading legal philosophers of this century, Kelsen published this short treatise in 1934, when the neo-Kantian influence on his work was at its zenith. An earlier, "constructivist" phase had been displaced by his effort to provide something approximating a neo-Kantian foundation for his theory. If this second phase represents the Pure Theory of Law in its most characteristic form, then the present treatise may well be its central text. And of Kelsen's many statements of the Pure Theory, (...) this one is surely the most accessible. Topics covered include the legal norm and Kelsen's normativity thesis, law and morality, the role of ideology, the concept of the legal person, legal interpretation, the identity of law and state, and the theory of international law. Among the appendices is an annotated bibliography of secondary literature on Kelsen. (shrink)

In this article we give a unifying approach to the theory of fundamental sequences and their related Hardy hierarchies of number-theoretic functions and we show the equivalence of the new approach with the classical one.

In his classic paper On Computable Numbers Turing analyzed what can be done by a human computor in a routine, “mechanical” way. He argued that mechanical op-erations obey locality conditions and are carried out on configurations satisfying boundedness conditions. Processes meeting these restrictive conditions can be shown to be computable by a Turing machine. Turing viewed memory limitations of computors as the ultimate reason for the restrictive conditions. In contrast, Gandy analyzed in his paper Church’s Thesis and Principles for Mechanisms (...) what can be done by “discrete deterministic mechanical devices” and appealed to physical considerations to motivate restrictive principles. These devices include, crucially, ones that carry out parallel processes, e.g., cellular automata. Following Turing’s methodological ways and guided by Conway’s “Game of Life” as a paradigm, Gandy formulated four restrictive principles and proved that devices satisfying them are computationally equivalent to Turing machines. (shrink)

Since their inception, the Perspectives in Logic and Lecture Notes in Logic series have published seminal works by leading logicians. Many of the original books in the series have been unavailable for years, but they are now in print once again. This volume, the fifteenth publication in the Lecture Notes in Logic series, collects papers presented at the symposium 'Reflections on the Foundations of Mathematics' held in celebration of Solomon Feferman's 70th birthday (The 'Feferfest') at Stanford University, California in 1988. (...) Feferman has shaped the field of foundational research for nearly half a century. These papers reflect his broad interests as well as his approach to foundational research, which emphasizes the solution of mathematical and philosophical problems. There are four sections, covering proof theoretic analysis, logic and computation, applicative and self-applicative theories, and philosophy of modern mathematical and logic thought. (shrink)

Das Werk ist die erste komplett an allen Gebieten der Physik systematisch ausgerichtete Darstellung der Geschichte der Physik. Geschrieben von einem erfahrenen Didaktiker seines Faches und als Ergebnis jahrzehntelanger Recherche soll dieses Buch ein tieferes Verständnis seines Faches vermitteln, als dies traditionelle Lehrbücher vermögen. Der rote Faden sind die Konzepte und Theoriebildungen, wie sie sich durch die Jahrhunderte nachzeichnen lassen. Das Ergebnis ist ein lebendig geschriebenes Fachbuch, das sich sowohl zum Lernen und Nachschlagen systematisch nutzen wie auch als packende Physikgeschichte (...) von der ersten bis letzten Seite spannend lesen lässt. (shrink)

In this rapid commentary, a mini-review is given of the present state-of-knowledge regarding the etiology and epidemiology of the new coronavirus 2019-nCoV and the risks for developing Acute respiratory distress syndrome. The available knowledge on the viral genomics, molecular biology and pathogenicity of viruses of the Coronaviridae family and other Nidovirales, forms a helpful template for understanding the present pandemic outbreak. However, important questions remain unanswered about the underlying mechanism causing the very high case fatality ratios and mechanisms regarding severe (...) reactions like ARDS, fatal cardiac and renal failures, associated with a number of important comorbidity factors. Immunological reactions to lung alveoles in particular in late phase ARDS in SARS-like CoV diseases, so far may not have received enough attention. Finally a shortlist of questions for high priority further research is suggested. (shrink)

Using the concept of notations for infinitary derivations we give an explanation of Takeuti's reduction steps on finite derivations (used in his consistency proof for Π1 1-CA) in terms of the more perspicious infinitary approach from [BS88].