An observer principle for general relativity

We give a mathematical uniqueness theorem which in particular shows that symmetric tensors in general relativity are uniquely determined by their monomial functions on the light cone. Thus, for an observer to observe a tensor at an event in general relativity is to contract with the velocity vector of the observer, repeatedly to the rank of the tensor. Thus two symmetric tensors observed to be equal by all observers at a specific event are necessarily equal at that event.Comment: arXiv admin note: substantial text overlap with arXiv:0903.522

Life as process

This is the final version. Available from the publisher via the DOI in this record.The thesis of this paper is that our understanding of life, as reflected in the biological and medical sciences but also in our everyday transactions, has been hampered by an inappropriate metaphysics. The metaphysics that has dominated Western philosophy, and that currently shapes most understanding of life and the life sciences, sees the world as composed of things and their properties. While these things appear to undergo all kinds of changes, it has often been supposed that this amounts to no more than a change in the spatial relations of their unchanging parts. From antiquity, however, there has been a rival to this view, the process ontology, associated in antiquity with the fragmentary surviving writings of Heraclitus. In the last century it has been especially associated with the work of the British metaphysician and logician, Alfred North Whitehead. For process ontology, what most fundamentally exists is change, or process. What we are tempted to think of as constant things are in reality merely temporary stabilities in this constant flux of change, eddies in the flux of process. My main claim in this paper will be that a metaphysics of this latter kind is the only kind adequate to making sense of the living world. After explaining in more detail, the differences between these ontological views, I shall illustrate the advantages of a process ontology with reference to the category of organism. Finally I shall explore some further implications of a process ontology for biology and for philosoph

Social Reformers and Regulation: The Prohibition of Cigarettes in the U.S. and Canada

The apogee of anti-smoking legislation in North America was reached early in the last century. In 1903, the Canadian Parliament passed a resolution prohibiting the manufacture, importation, and sale of cigarettes. Around the same time, fifteen states in the United States banned the sale of cigarettes and thirty-five states considered prohibitory legislation. In both the United States and Canada, prohibition was part of a broad political, economic, and social coalition termed the Progressive Movement. Cigarette prohibition was special interest regulation, though not of the usual narrow neoclassical genre; it was the means by which a group of crusaders sought to alter the behavior of a much larger segment of the population. The opponents of cigarette regulation were cigarette smokers and the more organized cigarette lobby. An active Progressive Movement was the necessary condition for generating interest in prohibition, while the anti-prohibition forces played a more significant role later in the legislative process. The moral reformers' succeeded when they faced little opposition because few constituents smoked and/or no jobs were at stake because there was no cigarette industry. In other words, reform is easy when you are preaching to the converted.

Sub-Doppler frequency metrology in HD for test of fundamental physics

Weak transitions in the (2,0) overtone band of the HD molecule at $\lambda = 1.38 \, \mu$m were measured in saturated absorption using the technique of noise-immune cavity-enhanced optical heterodyne molecular spectroscopy. Narrow Doppler-free lines were interrogated with a spectroscopy laser locked to a frequency comb laser referenced to an atomic clock to yield transition frequencies [R(1) = $217\,105\,181\,895\,(20)$ kHz; R(2) = $219\,042\,856\,621\,(28)$ kHz; R(3) = $220\,704\,304\,951\,(28)$ kHz] at three orders of magnitude improved accuracy. These benchmark values provide a test of QED in the smallest neutral molecule, and open up an avenue to resolve the proton radius puzzle, as well as constrain putative fifth forces and extra dimensions.Comment: 5 pages, 4 figure

F05RS SGR No. 6 (Flag)

A RESOLUTION To discourage the use of the purple and gold Confederate Navy Jack on the LSU campus and discuss its negative impact on the Universit

Drawing and the dynamic nature of living systems

This is the final version. Available from eLife Sciences Publications via the DOI in this record.Representing the dynamic nature of biological processes is a challenge. This article describes a collaborative project in which the authors – a philosopher of biology, an artist and a cell biologist – explore how best to represent the entire process of cell division in one connected image. This involved a series of group Drawing Labs, one-to-one sessions, and discussions between the authors. The drawings generated during the collaboration were then reviewed by four experts in cell division. We propose that such an approach has value, both in communicating the dynamic nature of biological processes and in generating new insights and hypotheses that can be tested by artists and scientists.Arts and Humanities Research Counci

Causally powerful processes

This is the final version. Available on open access from Springer via the DOI in this recordProcesses produce changes: rivers erode their banks and thunderstorms cause floods. If I am right that organism are a kind of process, then the causally efficacious behaviours of organisms are also examples of processes producing change. In this paper I shall try to articulate a view of how we should think of causation within a broadly processual ontology of the living world. Specifically, I shall argue that causation, at least in a central class of cases, is the interaction of processes, that such causation is the exercise of a capacity inherent in that process and, negatively, that causation should not be understood as the instantiation of universal laws. The approach I describe has substantial similarities with the process causality articulated by Wesley Salmon and Phil Dowe for physical causation, making it plausible that the basic approach can be applied equally to the non-living world. It is an approach that builds at crucial points on the criticisms of determinism and universal causality famously articulated by Elizabeth Anscombe