Space, supervenience and substantivalism

[FIRST PARAGRAPH] Consider a straight line on a flat surface running from point A to C and passing though B. Suppose the distance AB to be four inches, and the distance BC to be six inches. We can infer that the distance AC is ten inches. Of all geometrical inferences, this is surely one of the simplest. Of course, things are a little more complicated if the surface is not flat. If A, B and C are points on a sphere, then the shortest distance between A and C may be smaller (it may even be zero). We can make our inference immune from concerns about non-Euclidean spaces, however, by qualifying it as follows: if AB = n, and BC = m, then, in the direction A⇒B⇒C, the distance AC is n + m. This is apparently entirely trivial. But trivial truths can hide significant ontological ones. Let us translate our mathematical example to the physical world, and suppose A, B and C to be points, still in a straight line, but now at the centre of gravity of three physical objects

Missing Elements and Missing Premises: A Combinatorial Argument for the Ontological Reduction of Chemistry

Does chemistry reduce to physics? If this means Can we derive the laws of chemistry from the laws of physics?', recent discussions suggest that the answer is no'. But sup posing that kind of reduction-- epistemological reduction'--to be impossible, the thesis of ontological reduction may still be true: that chemical properties are determined by more fundamental properties. However, even this thesis is threatened by some objections to the physicalist programme in the philosophy of mind, objections that generalize to the chemical case. Two objections are discussed: that physicalism is vacuous, and that nothing grounds the asymmetry of dependence which reductionism requires. Although it might seem rather surprising that the philosophy of chemistry is affected by shock waves from debates in the philosophy of mind, these objections show that there is an argumentative gap between, on the one hand, the theoretical connection linking chemical properties with properties at the sub-atomic level, and, on the other, the philosophical thesis of ontological reduction. The aim of this paper is to identify the missing premises (among them a theory of physical possibility) that would bridge this gap. Introduction: missing elements and the mystery of discreteness The refutation of physicalism A combinatorial theory of physical possibilia Combinatorialism and the Bohr model Objections The missing premises and a disanalogy with min

Time, and the static image

Photographs, paintings, rigid sculptures: all these provide examples of static images. It is true that they change-photographs fade,paintings darken and sculptures crumble-but what change they undergo (unless very damaging) is irrelevant to their representational content. A static image is one that represents by virtue of properties which remain largely unchanged throughout its existence. Because of this defining feature, according to a long tradition in aesthetics, a static image can only represent an instantaneous moment, or to be more exact the state of affairs obtaining at that moment'. It cannot represent movement and the passage of time. This traditional vieu- mirrors a much older one in metaphysics: that change is to be conceived of as a series of instantaneous states and hence that an interval of time is composed of extensionless moments. The metaphysical view has been involved in more controversy than its aesthetic counterpart. Aristotle identified it as one of the premises of Zeno's arrow paradoxZ and Augustine employed it in his proof of the unreality of time. The aesthetic view, for its part, was subjected to a blistering attack in Ernst Gombrich's brilliant essay 'Moment and movement in Art'", uhich persuasively argues, not only against the doctrine that the changeless cannot represent change, but also against the very idea of an instant of time. Still, Gombrich overstates his case. Is the idea of an instant simply a philosophers' fiction? And if we allow such an idea into our conception of the world, are we thereby committed to a mistaken view of pictorial representation? Implicit in Gombrich's argument is a link between depiction and perception. But what is this link, and what role does it play in the argument? I propose in this essay to take another look at the question of what time-span is represented by the static image, and consider whether answering this question presupposes a view of time and change. I shall begin with a brief resume of Gombrich's discussion

Playing the God game: the perils of religious fictionalism

To what extend can someone who treat religious discourse as fictional discourse live a religious life, that is, one that is informed by that discourse? To what extent can they be integrated into a religious community in which the realist approach is dominant, or at least significantly represented? This paper explores both the possibilities and limitations, of religious fictionalism, and compares it with other non-realist approaches. Finally, a certain kind of agnostic position is presented, one which has something in common with fictionalism, and it is suggested that this latter position may offer the best way of combining religious engagement with a retreat from traditional realism

Multi-Scale Analysis of Magnetic Fields in Filamentary Molecular Clouds in Orion A

New visible and K-band polarization measurements on stars surrounding molecular clouds in Orion A and stars in the BN vicinity are presented. Our results confirm that magnetic fields located inside the Orion A molecular clouds and in their close neighborhood are spatially connected. On and around the BN object, we measured the angular offsets between the K-band polarization data and available submm data. We find high values of the polarization degree, P_{K}, and of the optical depth, \tau_{K}, close to an angular offset position of 90^{\circ} whereas lower values of P_{K} and \tau_{K} are observed for smaller angular offsets. We interpret these results as evidence for the presence of various magnetic field components toward lines of sight in the vicinity of BN. On a larger scale, we measured the distribution of angular offsets between available H-band polarization data and the same submm data set. Here we find an increase of with angular offset which we interpret as a rotation of the magnetic field by \lesssim 60^{\circ}. This trend generalizes previous results on small scale toward and around lines of sight to BN and is consistent with a twist of the magnetic field on a larger scale towards OMC-1. A comparison of our results with several other studies suggests that a two-component magnetic field, maybe helical, could be wrapping the OMC-1 filament.Comment: 53 pages, 21 figures, 7 tables, Accepted in the Astrophysical Journa

Comparison of Prestellar Core Elongations and Large-scale Molecular Cloud Structures in the Lupus I Region

Turbulence and magnetic fields are expected to be important for regulating molecular cloud formation and evolution. However, their effects on sub-parsec to 100 parsec scales, leading to the formation of starless cores, are not well understood. We investigate the prestellar core structure morphologies obtained from analysis of the Herschel-SPIRE 350 μm maps of the Lupus I cloud. This distribution is first compared on a statistical basis to the large-scale shape of the main filament. We find the distribution of the elongation position angle of the cores to be consistent with a random distribution, which means no specific orientation of the morphology of the cores is observed with respect to the mean orientation of the large-scale filament in Lupus I, nor relative to a large-scale bent filament model. This distribution is also compared to the mean orientation of the large-scale magnetic fields probed at 350 μm with the Balloon-borne Large Aperture Telescope for Polarimetry during its 2010 campaign. Here again we do not find any correlation between the core morphology distribution and the average orientation of the magnetic fields on parsec scales. Our main conclusion is that the local filament dynamics—including secondary filaments that often run orthogonally to the primary filament—and possibly small-scale variations in the local magnetic field direction, could be the dominant factors for explaining the final orientation of each core

Des animaux qui parlent d’or : le projet Animaliter à Strasbourg

Dans quelle mesure et par quels moyens une bibliothèque peut-elle tirer parti de grands projets initiés à l’échelle européenne ? Quelles opportunités peut-elle saisir pour développer un travail de coopération internationale ? Quels bénéfices en attendre ? Qu’ont donc à nous dire les animaux qui parlent