In quantum mechanics, the expression for entropy is usually taken to be -kTr(ln), where is the density matrix. The convention first appears in Von Neumann's Mathematical Foundations of Quantum Mechanics. The argument given there to justify this convention is the only one hitherto offered. All the arguments in the field refer to it at one point or another. Here this argument is shown to be invalid. Moreover, it is shown that, if entropy is -kTr(ln), then perpetual motion machines are possible. (...) This and other considerations support the conclusion that this expression is not the quantum-mechanical correlate of thermodynamic entropy. Its usefulness in quantum-statistical mechanics can be explained by its being a convenient quantification of information, but information and entropy are not synonymous. As the present paper shows, one can change while the other is conserved. (shrink)

In The Sources of Normativity Korsgaard introduces her conception of practical identities understood as the source of moral obligations. This conception forms a point of transition from Korsgaard’s theory of action to her solution to the problem of the authority of moral norms. In order to describe how universal categorical reasoning is compatible with the moral content of particular practical decisions, Korsgaard needs to show how our contingent practical identities can be reconciled with what she defines as the universally shared (...) identity that expresses our humanity. To make this reconciliation work, she devises an argument for the public shareability of reasons amended by her reinterpretation of the Kantian as if principle. I suggest that, in doing so, Korsgaard steps too far away from Kant’s architectonic approach to the question of why moral norms bind us, and that, consequently, the Korsgaardian reconciliation between the two kinds of identities, as it stands, cannot be accomplished. (shrink)

Zusammenfassung Die empirische Dauerproduktion immer neuer Zahlenkolonnen lässt kaum Zweifel am Ernst der Lage: Deutsche Kinder stecken in einer nie da gewesenen Fett- und Fitnessmisere. Beachtliche Resonanzwerte bezieht diese alarmierende Befundlage nicht zuletzt im Revier sportpädagogischer Kommunikation, die feldgerecht auf unverzichtbare Lösungspotenziale verweisen kann. Der vorliegende Beitrag bringt „inkongruente Perspektiven“ in Anschlag: Nach einer Analyse semantischer und struktureller Voraussetzungen der Kriseninklusion liegt das Augenmerk auf deren Funktionssinn: Dicke Kinder, unfitte Körper - es sind nicht zuletzt die allerneuesten somatogenen Trägheiten, an (...) denen sich Dynamik sportpädagogischer Reformkommunikation gegenwärtig aufschaukelt. Abschließende Reflexionen spielen das Panorama übergangener „Risiken und Nebenwirkungen“ dieses Typs von Krisenkommunikation ein. (shrink)