This paper provides a method for characterizing space events using the framework of conceptual spaces. We focus specifically on estimating and ranking the likelihood of collisions between space objects. The objective is to design an approach for anticipatory decision support for space operators who can take preventive actions on the basis of assessments of relative risk. To make this possible our approach draws on the fusion of both hard and soft data within a single decision support framework. Contextual data is (...) also taken into account, for example data about space weather effects, by drawing on the Space Domain Ontologies, a large system of ontologies designed to support all aspects of space situational awareness. The framework is coupled with a mathematical programming scheme that frames a mathematically optimal approach for decision support, providing a quantitative basis for ranking potential for collision across multiple satellite pairs. The goal is to provide the broadest possible information foundation for critical assessments of collision likelihood. (shrink)

This paper describes an AFOSR-supported basic research program that focuses on developing a new framework for combining hard with soft data in order to improve space situational awareness. The goal is to provide, in an automatic and near real-time fashion, a ranking of possible threats to blue assets (assets trying to be protected) from red assets (assets with hostile intentions). The approach is based on Conceptual Spaces models, which combine features from traditional associative and symbolic cognitive models. While Conceptual Spaces (...) are revolutionary, they lack an underlying mathematical framework. Several such frameworks have attempted to represent Conceptual Spaces, but by far the most robust is the model developed by Holender. His model utilizes integer linear programming in order to obtain an overall similarity value between observations and concepts that support the formation of hypotheses. This paper will describe a method for building Conceptual Spaces models for threats that utilizes ontologies as a means to provide a clear semantic foundation for this inferencing process; in particular threat ontologies and space domain ontologies are developed and employed in this approach. A space situational awareness use-case is presented involving a kinetic kill scenario and results are shown to assess the performance of this fusion-based inferencing framework. (shrink)

The overall goal of the approach developed in this paper is to estimate the likelihood of a given kinetic kill scenario between hostile spacebased adversaries using the mathematical framework of Complex Conceptual Spaces Single Observation. Conceptual spaces are a cognitive model that provide a method for systematically and automatically mimicking human decision making. For accurate decisions to be made, the fusion of both hard and soft data into a single decision framework is required. This presents several challenges to this data (...) fusion framework. The first is the challenge involved in handling multiple complex terminologies, which is addressed by drawing on a set of Space Domain Ontologies. Another challenge is the complex combinatorics involved when considering all possible feature combinations. This can be mitigated by using integer linear programming optimization that is outlined by the Complex Conceptual Spaces Single Observation mathematical model framework. A third challenge is the complicated physics that is involved in a spacecraft collision that must be addressed to obtain a better understanding of threat assessment. Overcoming these various challenges allows for a quantitative ranking for the potential of a kinetic kill collision across multiple spacecraft pairs. In addition to overcoming these challenges this paper will break down threat assessment into four domains and identify a ranking of threat both for each individual domain and for the four domains combined. Simulation results are shown to verify the developed concepts. (shrink)

PERSON AND OBJECT by Roderick M. Chisholm. U.K.: Allen & Unwin; U.S.A.: Humanities Press, 1976. 230 pp. £7.25.

John Dewey is a philosopher who seems perpetually on the verge of rhetoric. He displays a continual interest in the necessity of communication for democracy, and yet he often remains vague as to what shape such communication should take. While this would seem to limit his usefulness for rhetoricians, the opposite has proven true. As scholars of rhetoric, we now find ourselves in the midst of a renaissance in studies of Dewey. Trained Capacities: John Dewey, Rhetoric, and Democratic Practice seeks (...) to both consolidate the gains made by such scholarship and further encourage rhetoricians’ interest in Dewey’s work. Namely, the various authors in this volume concern themselves with treating Dewey’s.. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:The Journal of Aesthetic Education 39.1 (2005) 105-118 [Access article in PDF] Sibley's Legacy Brandon Cooke Philosophy Department Auburn University Approach To Aesthetics, by Frank Sibley. John Benson, Betty Redfern, and Jerome Roxbee Cox, editors. Oxford: Clarendon Press, 2001, 280 pp., $45.00 hardcover. Aesthetic Concepts: Essays After Sibley, edited by Emily Brady and Jerrold Levinson. Oxford: Clarendon Press, 2001, 239 pp., $49.95 hardcover. Unquestionably, Frank Sibley should be (...) counted among those who helped return aesthetics to intellectual health and respectability as a proper field for philosophical investigation. He published no monographs outlining his views, but managed nonetheless to make highly influential contributions to research in aesthetics through a small number of papers. The two books under review in a sense are long overdue. Sibley died in 1996, before he could assemble a collection of his papers for publication in a single volume. Approach to Aesthetics is perhaps the next best thing — a collection of essays assembled and shaped by a highly conscientious editorial team. The book collects all of Sibley's published writings in aesthetics, together with a number of unpublished papers in various states of completion. The editors were confronted with the difficult question of what to do with many of these latter pieces. In the end, they made the unhappy but correct decision to leave out some work, which would have been of great interest but was still embryonic at the time of Sibley's death. But while we may not have in this volume the fullness of Sibley's mature thinking on aesthetics, the importance of its contribution to the literature is in no way diminished. Clarendon has published Aesthetic Concepts: Essays After Sibley as a companion to the collection of Sibley's work. It, too, is a valuable contribution, and evidence of Sibley's agenda-setting influence on subsequent work in aesthetics. First I shall explore some of the main themes of Sibley's thought in Approach to Aesthetics. Approach to Aesthetics "Aesthetic Concepts" leads off the collection. Sibley concentrates on two sorts of remarks we make in talking about art: those that "may be made by...anyone with normal eyes, ears, and intelligence," and those that require "the exercise of taste, perceptiveness, or sensitivity, of aesthetic discrimination or appreciation" (p. 1). Concepts in the second group are aesthetic [End Page 105] or taste concepts. Sibley notices that in support of aesthetic judgments, we often (but not always) adduce reasons which involve non-aesthetic concepts only. The question to ask, then, is just what is the relation between the two? Sibley remains deliberately uncommitted on the specific nature of the relation, except for the important claim that whatever it is, it is not condition-governed. That is, "there are no non-aesthetic features which serve in any circumstances as logically sufficient conditions for applying aesthetic terms" (p. 4). The claim is strict, and in the tradition which says that nothing can substitute for individual, spontaneous contact with an artwork to judge its aesthetic qualities; no application of principles will suffice. On the one hand, such a position makes aesthetic education quite an important task, if the distinctive qualities of artworks are out of reach even to those who are cognitively and perceptually well-equipped. And yet, if no rules or general standards can be brought to the experience of art, one might well wonder just how such an education is to be carried out. Sibley is aware of this tension. The solution lies first in realizing that the aesthetic terminology is not different in kind from "everyday" language. Even if in the art-related cases, some of those are deployed in metaphors, our understanding of their use here is deeply related to their ordinary uses. But then, what stops any one of us from seeing that a painting is imbalanced or lurid? Sibley describes the several ways in which the critic "gets his audience to see what he sees" (p. 18). These include pointing out salient non-aesthetic features, using the aesthetic terms themselves, making use of metaphors, contrasts, comparisons, and so on. In effect, the critic's... (shrink)

We discuss from a philosophical perspective the way in which the normal concept of time might be said to `emerge' in a quantum theory of gravity. After an introduction, we briefly discuss the notion of emergence, without regard to time. We then introduce the search for a quantum theory of gravity ; and review some general interpretative issues about space, time and matter. We then discuss the emergence of time in simple quantum geometrodynamics, and in the Euclidean approach. Section 6 (...) concludes. (shrink)

Of all the demands that mathematics imposes on its practitioners, one of the most fundamental is that proofs ought to be correct. It has been common since the turn of the twentieth century to take correctness to be underwritten by the existence of formal derivations in a suitable axiomatic foundation, but then it is hard to see how this normative standard can be met, given the differences between informal proofs and formal derivations, and given the inherent fragility and complexity of (...) the latter. This essay describes some of the ways that mathematical practice makes it possible to reliably and robustly meet the formal standard, preserving the standard normative account while doing justice to epistemically important features of informal mathematical justification. (shrink)

We survey some philosophical aspects of the search for a quantum theory of gravity, emphasising how quantum gravity throws into doubt the treatment of spacetime common to the two `ingredient theories' (quantum theory and general relativity), as a 4-dimensional manifold equipped with a Lorentzian metric. After an introduction (Section 1), we briefly review the conceptual problems of the ingredient theories (Section 2) and introduce the enterprise of quantum gravity (Section 3). We then describe how three main research programmes in quantum (...) gravity treat four topics of particular importance: the scope of standard quantum theory; the nature of spacetime; spacetime diffeomorphisms, and the so-called `problem of time' (Section 4). These programmes are the old particle-physics approach, superstring theory, and canonical quantum gravity. By and large, these programmes accept most of the ingredient theories' treatment of spacetime, albeit with a metric with some type of quantum nature; but they also suggest that the treatment has fundamental limitations. This prompts the idea of going further: either by quantizing structures other than the metric, such as the topology; or by regarding such structures as phenomenological. We discuss this in Section 5. (shrink)

The main aim of this paper is to make a remark about the relation between dualities between theories, as `duality' is understood in physics and equivalence of theories, as `equivalence' is understood in logic and philosophy. The remark is that in physics, two theories can be dual, and accordingly get called `the same theory', though we interpret them as disagreeing---so that they are certainly not equivalent, as `equivalent' is normally understood. So the remark is simple: but, I shall argue, worth (...) stressing---since often neglected. My argument for this is based on the account of duality developed by De Haro: which is illustrated here with several examples, from both elementary physics and string theory. Thus I argue that in some examples, including in string theory, two dual theories disagree in their claims about the world. I also spell out how this remark implies a limitation of proposals to understand theoretical equivalence as either logical equivalence or a weakening of it. (shrink)

We have two aims. The main one is to expound the idea of renormalization in quantum field theory, with no technical prerequisites. Our motivation is that renormalization is undoubtedly one of the great ideas—and great successes--of twentieth-century physics. Also it has strongly influenced in diverse ways, how physicists conceive of physical theories. So it is of considerable philosophical interest. Second, we will briefly relate renormalization to Ernest Nagel's account of inter-theoretic relations, especially reduction. One theme will be a contrast between (...) two approaches to renormalization. The old approach, which prevailed from ca. 1945 to 1970, treated renormalizability as a necessary condition for being an acceptable quantum field theory. On this approach, it is a piece of great good fortune that high energy physicists can formulate renormalizable quantum field theories that are so empirically successful. But the new approach to renormalization explains why the phenomena we see, at the energies we can access in our particle accelerators, are described by a renormalizable quantum field theory. For whatever non-renormalizable interactions may occur at yet higher energies, they are insignificant at accessible energies. Thus the new approach explains why our best fundamental theories have a feature, viz. renormalizability, which the old approach treated as a selection principle for theories. That is worth saying since philosophers tend to think of scientific explanation as only explaining an individual event, or perhaps a single law, or at most deducing one theory as a special case of another. Here we see a framework in which there is a space of theories. And this framework is powerful enough to deduce that what seemed “manna from heaven” is to be expected: the good fortune is generic. We also maintain that universality, a concept stressed in renormalization theory, is essentially the familiar philosophical idea of multiple realizability; and that it causes no problems for reductions of a Nagelian kind. (shrink)

I have two main aims. The first is general, and more philosophical. The second is specific, and more closely related to physics. The first aim is to state my general views about laws and causation at different ”levels’. The main task is to understand how the higher levels sustain notions of law and causation that ”ride free’ of reductions to the lower level or levels. I endeavour to relate my views to those of other symposiasts. The second aim is to (...) give a framework for describing dynamics at different levels, emphasizing how the various levels’ dynamics can mesh or fail to mesh. This framework is essentially that of elementary dynamical systems theory. The main idea will be, for simplicity, to work with just two levels, dubbed ”micro’ and ”macro’, which are related by coarse-graining. I use this framework to describe, in part, the first four of Ellis’ five types of top-down causation. (shrink)

We present a formal system, E, which provides a faithful model of the proofs in Euclid's Elements, including the use of diagrammatic reasoning.

Proponents of evidence-based medicine and some philosophers of science seem to agree that knowledge of mechanisms can help solve the problem of applying results of controlled studies to target populations (‘the problem of extrapolation’). We describe the problem of extrapolation, characterize mechanisms, and outline how mechanistic knowledge might be used to solve the problem. Our main thesis is that there are four often overlooked problems with using mechanistic knowledge to solve the problem of extrapolation. First, our understanding of mechanisms is (...) often (and arguably, likely to remain) incomplete. Secondly, knowledge of mechanisms is not always applicable outside the tightly controlled laboratory conditions in which it is gained. Thirdly, mechanisms can behave paradoxically. Fourthly, as Daniel Steel points out, using mechanistic knowledge faces the problem of the ‘extrapolator’s circle’. At the same time, when the problems with mechanistic knowledge have been addressed, such knowledge can and should be used to mitigate (nothing can entirely solve) the problem of extrapolation. (shrink)

In another paper, one of us argued that emergence and reduction are compatible, and presented four examples illustrating both. The main purpose of this paper is to develop this position for the example of phase transitions. We take it that emergence involves behaviour that is novel compared with what is expected: often, what is expected from a theory of the system's microscopic constituents. We take reduction as deduction, aided by appropriate definitions. Then the main idea of our reconciliation of emergence (...) and reduction is that one makes the deduction after taking a limit of an appropriate parameter $N$. Thus our first main claim will be that in some situations, one can deduce a novel behaviour, by taking a limit $N\to\infty$. Our main illustration of this will be Lee-Yang theory. But on the other hand, this does not show that the $N=\infty$ limit is physically real. For our second main claim will be that in such situations, there is a logically weaker, yet still vivid, novel behaviour that occurs before the limit, i.e. for finite $N$. And it is this weaker behaviour which is physically real. Our main illustration of this will be the renormalization group description of cross-over phenomena. (shrink)

In a wide range of fields, the word “modular” is used to describe complex systems that can be decomposed into smaller systems with limited interactions between them. This essay argues that mathematical knowledge can fruitfully be understood as having a modular structure and explores the ways in which modularity in mathematics is epistemically advantageous.