In order to understand the rise of runaway solutions in the radiation reaction problem a mechanical model is used. An alternative demonstration of Daboul’s theorem, through Hurwitz’s criterion, is given. The origin of runaway solutions in electrodynamics is discussed. They arise when the particle has a negative mechanical mass or when approximations are used in the equation of motion. In the 1-dimensional mechanical model an exact and linear equation of motion for the particle is obtained, the corresponding exact solution is (...) again runaway when the mechanical mass is negative. The exact solution is not runaway when the mechanical mass is positive. However, the use of approximations leads to an equation of motion which has runaway solutions. It is exhibited that the use of approximations in the 3-dimensional mechanical model is completely necessary because the general equation of motion for the particle is non-linear. The analysis of this case proceeds in a very similar way to the one carried out in electrodynamics. This means that the number of dimensions also plays an important role in the analysis. (shrink)

__Forging People __explores the way in which Hispanic American thinkers in Latin America and Latino/a philosophers in the United States have posed and thought about questions of race, ethnicity, and nationality, and how they have interpreted the most significant racial and ethnic labels used in Hispanic America in connection with issues of rights, nationalism, power, and identity. Following the first introductory chapter, each of the essays addresses one or more influential thinkers, ranging from Bartolomé de Las Casas on race and (...) the rights of Amerindians; to Simon Bolívar's struggle with questions of how to forge a nation from disparate populations; to modern and contemporary thinkers on issues of race, unity, assimilation, and diversity. Each essay carefully and clearly presents the views of key authors in their historical and philosophical context and provides brief biographical sketches and reading lists, as aids to students and other readers. “Latin American philosophy has a long history of engagement with issues of race, ethnicity, and nationality. To date, however, there has been no volume that focused on the contributions of the major figures in the Latin American tradition, to illustrate their connections, and to illuminate the context in which much of their work occurred. This volume fills that gap and takes an important step in remedying this shortcoming in the existing philosophical literature, and also in the literature of related fields such as Latin American studies, ethnic studies, and the cross-disciplinary work of race, ethnicity, and nationality.” —_Manuel Vargas, University of San Francisco _. (shrink)

How do people understand the concepts of mental health and disorder? The objective of this paper is to examine the impact of several factors on people’s judgments about whether a condition constitutes a mental disorder or a healthy state. Specifically, this study examines the impact of the source of the condition, its outcome, individual valuation (i.e., the value the individual attaches to the condition), and group valuation (i.e., the value the relevant group attaches to the condition). While we find that (...) people’s health and disorder judgments are driven by perceived dysfunction, we also find that health and disorder judgments are impacted differently by these factors. Health judgements are impacted by outcome and individual valuation, and disorder judgments are impacted by condition source. These results suggest that the folk concept of mental health is positive (i.e., mental health is more than the absence of mental disorder) and normativist (i.e., value judgments play a significant role in determining whether a condition counts as healthy), while the concept of mental disorder aligns with a naturalist perspective, at least to the extent that dysfunction plays an important role in categorizing a condition as a disorder. However, our finding that people’s dysfunction judgments are influenced by individual valuation and outcomes poses a strong challenge to naturalist accounts. To provide access to our supplementary data, an appendix has been included. (shrink)

Good academic practice is more than the avoidance of clear-cut cheating. It also involves navigation of the gray zones between cheating and good practice. The existing literature has left students’ understanding of gray zone practices largely unexplored. To begin filling in this gap, we present results from a questionnaire study involving N = 1639 undergraduate students from seven European countries representing all major disciplines. We show that large numbers of these students are unable to identify gray area issues and lack (...) sensitivity to the context dependence of these. We also show that a considerable proportion of students have a poor understanding of concepts like plagiarism and falsification, not only in gray zone scenarios, but also in cases of relatively clear-cut cheating. Our results are similar across the faculties and countries of study, and even for students who have attended academic integrity training. We discuss the implications of this for academic integrity training. (shrink)

To attain native-like competence, second language (L2) learners must establish mappings between familiar speech sounds and new phoneme categories. For example, Spanish learners of English must learn that [d] and [ð], which are allophones of the same phoneme in Spanish, can distinguish meaning in English (i.e. /deɪ/ ‘day’ and /ðeɪ/ ‘they’). Because adult listeners are less sensitive to allophonic than phonemic contrasts in their native language (L1), novel target language contrasts between L1 allophones may pose special difficulty for L2 learners. (...) We investigate whether advanced Spanish late-learners of English overcome native language mappings to establish new phonological relations between familiar phones. We report behavioral and magnetoencepholographic (MEG) evidence from two experiments that measured the sensitivity and pre-attentive processing of three listener groups (L1 English, L1 Spanish, and advanced Spanish late-learners of English) to differences between three nonword stimulus pairs ([idi]-[iði], [idi]-[iɾi], and [iði]-[iɾi]) which differ in phones that play a different functional role in Spanish and English. Spanish and English listeners demonstrated greater sensitivity (larger d’ scores) for nonword pairs distinguished by phonemic than by allophonic contrasts, mirroring previous findings. Spanish late-learners demonstrated sensitivity (large d’ scores and MMN responses) to all three contrasts, suggesting that these L2 learners may have established a novel [d]-[ð] contrast despite the phonological relatedness of these sounds in the L1. Our results suggest that phonological relatedness influences perceived similarity, as evidenced by the results of the native speaker groups, but may not cause persistent difficulty for advanced L2 learners. Instead, L2 learners are able to use cues that are present in their input to establish new mappings between familiar phones. (shrink)

© 2017. The American Astronomical Society. All rights reserved.We present new observations of the low-mass companion to HD 984 taken with the Gemini Planet Imager as a part of the GPI Exoplanet Survey campaign. Images of HD 984 B were obtained in the J and H bands. Combined with archival epochs from 2012 and 2014, we fit the first orbit to the companion to find an 18 au orbit with a 68% confidence interval between 14 and 28 au, an eccentricity (...) of 0.18 with a 68% confidence interval between 0.05 and 0.47, and an inclination of 119°with a 68% confidence interval between 114°and 125°. To address the considerable spectral covariance in both spectra, we present a method of splitting the spectra into low and high frequencies to analyze the spectral structure at different spatial frequencies with the proper spectral noise correlation. Using the split spectra, we compare them to known spectral types using field brown dwarf and low-mass star spectra and find a best-fit match of a field gravity M6.5 ±1.5 spectral type with a corresponding temperature of K. Photometry of the companion yields a luminosity of log=2.88 ± 0.07 dex with DUSTY models. Mass estimates, again from DUSTY models, find an age-dependent mass of 34 ±1 to 95 ±4 M Jup. These results are consistent with previous measurements of the object. (shrink)

We present a one per cent measurement of the cosmic distance scale from the detections of the baryon acoustic oscillations in the clustering of galaxies from the Baryon Oscillation Spectroscopic Survey, which is part of the Sloan Digital Sky Survey III. Our results come from the Data Release 11 sample, containing nearly one million galaxies and covering approximately 8500 square degrees and the redshift range 0.2 < z < 0.7. We also compare these results with those from the publicly released (...) DR9 and DR10 samples. Assuming a concordance Λ cold dark matter cosmological model, the DR11 sample covers a volume of 13 Gpc3 and is the largest region of the Universe ever surveyed at this density. We measure the correlation function and power spectrum, including density-field reconstruction of the BAO feature. The acoustic features are detected at a significance of over 7σ in both the correlation function and power spectrum. Fitting for the position of the acoustic features measures the distance relative to the sound horizon at the drag epoch, rd, which has a value of rd,fid = 149.28 Mpc in our fiducial cosmology. We find DV = at z = 0.32 and DV = at z = 0.57. At 1.0 per cent, this latter measure is the most precise distance constraint ever obtained from a galaxy survey. Separating the clustering along and transverse to the line of sight yields measurements at z = 0.57 of DA = and H =. Our measurements of the distance scale are in good agreement with previous BAO measurements and with the predictions from cosmic microwave background data for a spatially flat CDM model with a cosmological constant. © 2014 The Author Published by Oxford University Press on behalf of the Royal Astronomical Society. (shrink)

A connection viewed from the perspective of integration has the Bianchi identities as constraints. It is shown that the removal of these constraints admits a natural solution on manifolds endowed with a metric and teleparallelism. In the process, the equations of structure and the Bianchi identities take standard forms of field equations and conservation laws.The Levi-Civita (part of the) connection ends up as the potential for the gravity sector, where the source is geometric and tensorial and contains an explicit gravitational (...) contribution.Nonlinear field equations for the torsion result. In a “low-energy” approximation (linearity andlow energy-momentumtransfer), the postulate that only charge and velocities contribute to the source transforms these equations into the Maxwell system. Moreover, the affine geodesics become the equations of motion of special relativity with Lorentz force in the same approximation [J. G. Vargas,Found. Phys. 21, 379 (1991)]. The field equations for the torsion must then be viewed as applying to an electromagnetic/strong interaction.A classical unified theory thus arises where the underlying geometry confers their contrasting characters to Maxwell-Lorentz electrodynamics and to an Einstein's-like theory of gravity. The highly compact field equations must, however, be developed in phase-spacetime, since the connection is velocity-dependent, i.e., Finsler-like.Further opportunities for similarities with present-day physics are discussed: (a) teleparallelism allows for the formulation of the torsion sector of the theory as a flat space theory with concomitant point-dependent transformations; (b) spinors should replace Lorentz frames in their role as the subjects to which the connection refers; (c) the Dirac equation consistent with the frame bundle for a velocity-dependent metric with Lorentz signature generates a weak-like interaction in the torsion sector. (shrink)

Limits to Action: The Allocation of Individual Behavior presents the ideas and methods in the study of how individual organisms allocate their limited time and energy and the consequences of such allocation. The book is a survey of individual resource allocation, emphasizing the relationships of the concepts of utility, reinforcement, and Darwinian fitness. The chapters are arranged beginning with plants and general evolutionary considerations, through animal behavior in nature and laboratory, and ending with human behavior in suburb and institution. Topics (...) discussed include operant conditioning; the principle of diminishing returns; and issues in relation to mating strategies. Biologists, sociologists, economists, and psychologists will find the book interesting. (shrink)

What are physical quantities, and in particular, what makes them quantitative? This book presents an original answer to this question through the novel position of substantival structuralism, arguing that quantitativeness is an irreducible feature of attributes, and quantitative attributes are best understood as substantival structured spaces.

Analogies must be symmetric. If a is like b, then b is like a. So if a has property R, and if R is within the scope of the analogy, then b (probably) has R. However, analogical arguments generally single out, or depend upon, only one of a or b to serve as the basis for the inference. In this respect, analogical arguments are directed by an asymmetry. I defend the importance of this neglected – even when explicitly mentioned – (...) feature in understanding analogical arguments. (shrink)

Manuscript Add. 3965, section 13, folios 541r–542r and 545r–546r is in the Portsmouth Collection of manuscripts and housed in the University Library, Cambridge. These drafts contain a careful account, in Newton's hand, of his views on place, time, and God. They are part of a large number of drafts relating to the three official editions of the Principia published in Newton's lifetime.

'To think often, and never to retain it so much as one moment, is a very useless sort of thinking' In An Essay concerning Human Understanding, John Locke sets out his theory of knowledge and how we acquire it. Eschewing doctrines of innate principles and ideas, Locke shows how all our ideas, even the most abstract and complex, are grounded in human experience and attained by sensation of external things or reflection upon our own mental activities. A thorough examination of (...) the communication of ideas through language and the conventions of taking words as signs of ideas paves the way for his penetrating critique of the limitations of ideas and the extent of our knowledge of ourselves, the world, God, and morals. Locke's masterpiece laid the foundation of British empiricism and is of enduring interest to anyone exploring the development of philosophical thought. This sensitive abridgement uses P. H. Nidditch's authoritative text, and together with an illuminating introduction and other features, makes Locke's arguments more accessible. (shrink)

: This article is concerned with Newton's appropriation of Descartes' ontology of true and immutable natures in developing his theory of infinitely extended space. It contends that unless the part played by the Platonic distinction between "being a nature" and "having a nature" in Newton's thinking is properly appreciated the foundation of his doctrine of space in relation to God will not be fully understood. It also contends that Newton's Platonism is consistent with his empiricism once the mediating role is (...) made clear that the geometry of moving loci play in grounding his intuitions concerning infinite natures. (shrink)

This book is available either individually, or as part of the specially-priced Arguments of the Philosphers Collection.

Measurement realism, the view that measurement targets quantitative attributes and that not all attributes are quantitative, has come under attack both from metrologists and philosophers. In this paper, I take a close look at two influential arguments against measurement realism: the argument from obsolescence and the argument from coordination. I concede that these arguments do challenge the epistemological position traditionally taken by measurement realists, but argue that the metaphysical core of measurement realism survives the challenge posed by these arguments. This (...) metaphysical core is vital to maintaining a clear and ambitious standard for successful measurement. (shrink)

Recent literature on causation invokes a distinction between deviant and default behavior to account for token causation. Critical examination of two prominent attempts to employ a distinction between deviants and defaults reveals that the distinction is far from clear. I clarify and develop the distinction by appeal to the notion of a modally robust process, and show how the distinction can be employed by causal process theorists to respond to cases of causation by omission. This shows that the default/deviant distinction (...) is not so much a tool for counterfactual accounts of causation, but rather for causal process theory. (shrink)

This study considers Newton's views on space and time with respect to some important ontologies of substance in his period. Specifically, it deals in a philosophico-historical manner with his conception of substance, attribute, existence, to actuality and necessity. I show how Newton links these “features” of things to his conception of God's existence with respect of infinite space and time. Moreover, I argue that his ontology of space and time cannot be understood without fully appreciating how it relates to the (...) nature of Divine existence. In order to establish this, the ontology embodied in Newton's theory of predication is analysed, and shown to be different from the presuppositions of the ontological argument. From the historical point of view Gassendi's influence is stressed, via the mediation of Walter Charleton. Furthermore, Newton's thought on these matters is contrasted with Descartes's and Spinoza's. In point of fact, in his earliest notebook Newton recorded observations on Descartes's version of the ontological argument. Soon, however, he was to oppose the Cartesian conception of the actuality of Divine existence by means of arguments similar to those of Gassendi. Lastly, I suggest that the nature and extent of Henry More's influence on Newton's conception of how God relates to absolute space and time bears further examination. (shrink)

Music raises many problems for those who would understand it more deeply. It is rooted in time, yet timeless. It is pure form, yet conveys emotion. It is written, but performed, interpreted, improvised, transcribed, recorded, sampled, remixed, revised, rebroadcast, reinterpreted, and more. Music can be studied by philosophers, psychologists, sociologists, mathematicians, biologists, computer scientists, neuro-scientists, critics, politicians, promoters, and of course musicians. Moreover, no single perspective seems either sufficient or invalid. This situation is not so different from that of other (...) arts, but perhaps more intense, due to the pervasiveness of pop, the inaccessability of much contemporary classical music, the strong cultural associations of many styles, the infusions of technology, and the combination with lyrics. (shrink)

It is standardly assumed that there are three — and only three — ways to solve problem of temporary intrinsics: (a) embrace presentism, (b) relativize property possession to times, or (c) accept the doctrine of temporal parts. The first two solutions are favoured by endurantists, whereas the third is the perdurantist solution of choice. In this paper, I argue that there is a further type of solution available to endurantists, one that not only avoids the usual costs, but is structurally (...) identical to the temporal-parts solution preferred by perdurantists. In addition to providing a general characterization of this new type of solution, I discuss certain of its anticipations in the literature on bundle theory, as well as provide a detailed development of it in terms of my own preferred metaphysics of ordinary objects — namely, a distinctive form of substratum theory tracing to Aristotle. (shrink)

The subject is in both cases the voyage of the Argo, and therefore the use of the same words is not likely to be coincidental, even though the words themselves are scarcely uncommon. One would hesitate to deny, however, that such reminiscence might be unconscious; that Lucan had famous tags in his head is suggested by another allusion to famous opening lines.

Isaac Newton wrote the manuscript Questiones quaedam philosophicae at the very beginning of his scientific career. This small notebook thus affords rare insight into the beginnings of Newton's thought and the foundations of his subsequent intellectual development. The Questiones contains a series of entries in Newton's hand that range over many topics in science, philosophy, psychology, theology, and the foundations of mathematics. These notes, written in English, provide a very detailed picture of Newton's early interests, and record his critical appraisal (...) of contemporary issues in natural philosophy. Written predominantly in 1664-5, they give a significant perspective on Newton's thought just prior to his annus mirabilis, 1666. This volume provides a complete transcription of the Questiones, together with an 'expansion' into modern English, and a full editorial commentary on the content and significance of the notebook in the development of Newton's thought. It will be essential reading for all those interested in Newton and the intellectual foundations of science. (shrink)