Heads and Tails: Molecular Imagination and the Lipid Bilayer, 1917–1941

Today, the lipid bilayer structure is nearly ubiquitous, taken for granted in even the most rudimentary introductions to cell biology. Yet the image of the lipid bilayer, built out of lipids with heads and tails, went from having obscure origins deep in colloid chemical theory in 1924 to being “obvious to any competent physical chemist” by 1935. This chapter examines how this schematic, strictly heuristic explanation of the idea of molecular orientation was developed within colloid physical chemistry, and how the image was transformed into a reflection of the reality and agency of lipid molecules in the biological microworld. Whereas in physical and colloid chemistry these images considered secondary to instrumental measurement and mathematical modeling of surface phenomena, in biology the manipulable image of the lipid on paper became an essential tool for the molecularization of the cell

A Failed Encounter in Mathematics and Chemistry: The Folded Models of van ‘t Hoff and Sachse

Three-dimensional material models of molecules were used throughout the 19th century, either functioning as a mere representation or opening new epistemic horizons. In this paper, two case studies are examined: the 1875 models of van ‘t Hoff and the 1890 models of Sachse. What is unique in these two case studies is that both models were not only folded, but were also conceptualized mathematically. When viewed in light of the chemical research of that period not only were both of these aspects, considered in their singularity, exceptional, but also taken together may be thought of as a subversion of the way molecules were chemically investigated in the 19th century. Concentrating on this unique shared characteristic in the models of van ‘t Hoff and the models of Sachse, this paper deals with the shifts and displacements between their operational methods and existence: between their technical and epistemological aspects and the fact that they were folded, which was forgotten or simply ignored in the subsequent development of chemistry

Reconciling visions and realities of virtual working: findings from the UK chemicals industry

The emergence of advanced technologies such as Grid computing will, some suggest, allow the final realisation of visions of virtual organisations. This will, according to its advocates, have entirely positive impacts, creating communities of experts, increasing flexibility, reducing the need for travel and making communications more efficient by crossing boundaries of time and space. Such predictions about future patterns of virtual working are, unfortunately, rarely grounded in real working practices, and often neglect to account for both the rich and varied interpretations that may exist of what constitutes virtual working and the constraints and concerns of those who would do it. This chapter gives attention to the consequences of different views over what virtuality might mean in practice and, in particular, considers virtuality in relation to customer and supplier relationships in a competitive and commercial context. The discussion is based upon a three year study that investigated contrasting visions of what was technically feasible and might be organisationally desirable in the UK Chemicals industry. Through interviews with managers and staff of companies both large and small that research provided insights into the different meanings that organisations attribute to the virtuality of work and to the acceptability of potential implementations of a middleware technology. It was found that interpretations of virtuality amongst the potential users and participants were strongly influenced by established work practices and by previous experiences of relationships-at-a-distance with suppliers and customers. There was a sharp contrast with the enthusiastic visions of virtual working that were already being encapsulated in the middleware by the technical developers; visions of internet-only interaction were perceived as rigid, alienating from well-established ways of working with suppliers and customers and unworkable. In this chapter we shall capture these differences by making a distinction amongst compet

Chemical Concepts in the Era of Computational Chemistry

Present work in the philosophy of chemistry has overlooked a foundational debate among chemists about the proper function of chemical concepts. The debate is fueled by a desire to connect computational models with traditional chemical concepts, and has divided chemists since the origins of quantum chemistry. By analyzing the history of the concepts of electronegativity and the atom in the molecule, I show that there are two camps with conflicting priorities. Theorists who favor rigor seek concepts that neatly summarize important elements of the underlying physical models. Theorists who favor understanding seek concepts that achieve a balance between simplicity and qualitative accuracy. The development of concepts for understanding is shown to involve the use of multiple quantification schemes in order to achieve consistency with other concepts. This practice might appear shortsighted if not for the diverse functionality of the resulting concepts. These concepts can i) help discover new reactions and structures, ii) allow comparison of different models in computational chemistry, and iii) guide chemists to develop more accurate and more interpretable computational models. Finally, it is shown that these conflicting modes of conceptual development have implications for the nature of chemical concepts. Chemists on each side of the debate adopt different positions, explicitly or tacitly, on reduction, pluralism, and the ontology of chemical concepts. Philosophers of chemistry who neglect this debate cannot responsibly interpret chemists’ statements on these issues

Alien life matters: reflections on cosmopolitanism, otherness, and astrobiology

This is a synaptic paper that invites the reader to take a stroll on the edges of cross-disciplinary knowledge. We will walk the roads of anthropology, history, philosophy, astronomy and biology. It is mainly a theoretical article, where I attempt to provide links between authors and theories that were, at first sight, unrelated. In doing so, this paper is aimed at making one controversial claim: ideologically and politically speaking, cosmopolitanism may never fully transcend itself beyond a debate until and unless humankind encounters alien life forms. The argument is based on a simple equation. Despite all the quarrels and debates around the concept, it seems innocuous to assume that cosmopolitanism is the search for a certain universal identity or, at least, a search for a common culturalia, i.e. the cultural grounds wherein local and global senses of universalism come into being (section 2). In spite of the fact that identities are built in opposition and supported by difference (section 3), cosmopolitanism might only be possible as a political project (cosmopolitics) when humankind is faced with life forms that are capable of providing true Otherness. I believe that this may explain why we have been fascinated by the utopias of extra-terrestrials for many centuries now (section 4). These utopias are present in a diverse array of knowledges, ranging from science to art, literature or even religion. They have been around for at least 500 years. Until now, all of them have been trapped in the realm of imagination, but there is one concrete cluster of knowledge that has attempted to transpose these imaginings into reality: the promising discipline of astrobiology. Astrobiology is mainly troubled by the de-naturalisation of Earth in order to create analogues for the study of life elsewhere in the cosmos. Provocatively, I end up this paper stating that this may well be the most cosmopolitical practice available to us (section 5)

‘The Action of the Brain’. Machine Models and Adaptive Functions in Turing and Ashby

Given the personal acquaintance between Alan M. Turing and W. Ross Ashby and the partial proximity of their research fields, a comparative view of Turing’s and Ashby’s work on modelling “the action of the brain” (letter from Turing to Ashby, 1946) will help to shed light on the seemingly strict symbolic/embodied dichotomy: While it is clear that Turing was committed to formal, computational and Ashby to material, analogue methods of modelling, there is no straightforward mapping of these approaches onto symbol-based AI and embodiment-centered views respectively. Instead, it will be demonstrated that both approaches, starting from a formal core, were at least partly concerned with biological and embodied phenomena, albeit in revealingly distinct ways

How and why physicists and chemists use blogs

This study examined how and why chemists and physicists blog. Two qualitative methods were used: content analysis of blog and “about” pages and in-depth responsive interviews with chemists and physicists who maintain blogs. Analysis of the data yielded several cross-cutting themes that provide a window into how physicists and chemists use their blogs and what value they receive from maintaining a blog and participating in a blogging community. The article concludes with a discussion of implications for supporting scientists’ work

Natural Kinds and Ceteris Paratis Generalizations: In Praise of Hunches

According to stereotypical logical empiricist conceptions, scientific findings are approximately true (or perhaps true ceteris paribus) law-like generalizations used to predict natural phenomena. They are deployed using topic-neutral, generally reliable inferential principles like deductive or statistical inferences. Natural kinds are the kinds in such generalizations. Chemical examples show that such conceptions are seriously incomplete. Some important chemical generalizations are true often enough, even though not usually true, and they are applied using esoteric topic- and discipline-specific inference rules. Their important methodological role is to underwrite often-enough reliable, often socially implemented, scientifically informed guessing about chemical phenomena. Some chemical natural kinds earn their naturalness mainly from participating in such generalizations. These results generalize: many scientific generalizations, inference rules, and natural kinds function to inform guessing, that is, to underwrite the generation of hunches