Duhem Before Breakfast

This essay traces some of Pierre Duhem's motives for his celebrated "Quine- Duhem thesis" to a specific worry about theory underdetermination that arises within classical mechanics, concerned with the rivalry between Duhem's own thermomechanical approach and the more narrowly "mechanical" treatment pursued by Hertz and others. In the context of the treatments of "physical infinitesimals" common at the time, these two approaches seem empirically indistinguishable. After an exposition of the basic issues, this alleged "underdetermination" is then evaluated from a more modern perspective

Determinism and the Mystery of the Missing Physics

This article surveys the difficulties in establishing determinism for classical physics in the context of several distinct foundational approaches to the discipline. It also explains that such formulations commonly appear in an incomplete condition due to a deeper problem of "missing physics.

The Campbell Paradigm as a Behavior-Predictive Reinterpretation of the Classical Tripartite Model of Attitudes.

In this article, we introduce the Campbell Paradigm as a novel variant of Rosenberg and Hovlands (1960) tripartite model of attitudes. The Campbell Paradigm is based on a highly restricted measurement model that speaks of a compensatory relation between a persons latent attitude and the costs that come with any specific behavior. It overcomes the overarching weakness of the original tripartite model (i.e., its relative irrelevance for actual behavior) and offers a parsimonious explanation for behavior. Even though this seems attractive, we also discuss why the paradigm has not gained momentum in the 50 years since it was originally proposed by Donald T. Campbell. To demonstrate the paradigms suitability even when implemented with an unrefined instrument in a domain where it has not been used previously, we apply the paradigm to a classic data example from attitude research from the 1984 US presidential election to account for the electorates voting intentions and actual voting behaviors

Congruence successions in compositions

A \emph{composition} is a sequence of positive integers, called \emph{parts}, having a fixed sum. By an \emph{$m$-congruence succession}, we will mean a pair of adjacent parts $x$ and $y$ within a composition such that $x\equiv y(\text{mod} m)$. Here, we consider the problem of counting the compositions of size $n$ according to the number of $m$-congruence successions, extending recent results concerning successions on subsets and permutations. A general formula is obtained, which reduces in the limiting case to the known generating function formula for the number of Carlitz compositions. Special attention is paid to the case $m=2$, where further enumerative results may be obtained by means of combinatorial arguments. Finally, an asymptotic estimate is provided for the number of compositions of size $n$ having no $m$-congruence successions

Probing the effects of steric bulk on the solution-phase behaviour and redox chemistry of cobalt-diimine complexes

Cobalt-diimine complexes are important structural and redox-active elements in supramolecular assemblies. However, functionalisation of the diimine ligand adjacent to the N-donor atoms can affect dramatically the types of Co-diimine complexes that can form and their redox activity. Herein, we compare the solution phase and redox chemistry of Co(II) complexes with 1,10-phenanthroline, 5,5′-dimethyl-2,2′-bipyridine and 2,9-dimethyl-1,10-phenanthroline (neocuproine). In acetonitrile solutions containing Co(NO3)2 and neocuproine, the dominant species is the mono-diimine complex [Co(neocuproine)(NO3)(CH3CN)2]+. This complex cannot be oxidised, either electrochemically nor with iodine. We rationalise this behaviour by considering the steric constraints placed upon the metal centre by the bulky methyl substituents on the neocuproine ligand. Furthermore, from solutions of [Co(neocuproine)(NO3)(CH3CN)2]+, crystals of formula [Co(neocuproine)2(NO3)]+·[Co(neocuproine)(NO3)3]− can be obtained. We believe that this work will guide the development of Co-diimine supramolecular assemblies by highlighting the extent to which substituents close to the N-donor atoms affect which species form in solution, and their likely redox activity