A point charge accelerating under the influence of an external force emits electromagnetic radiation that reduces the increase in its mechanical energy. This causes a reduction in the particle's acceleration. We derive the decrease in acceleration due to radiation reaction for a particle accelerating parallel to its velocity, and show that it has a negligible effect.

The meaning of Lorentz contraction in special relativity and its connection with Bell’s spaceships parable is discussed. The motion of Bell’s spaceships is then compared with the accelerated motion of a rigid body. We have tried to write this in a simple form that could be used to correct students’ misconceptions due to conflicting earlier treatments.

We study the acceleration and collisions of rigid bodies in special relativity. After a brief historical review, we give a physical definition of the term ‘rigid body’ in relativistic straight line motion. We show that the definition of ‘rigid body’ in relativity differs from the usual classical definition, so there is no difficulty in dealing with rigid bodies in relativistic motion. We then describe The motion of a rigid body undergoing constant acceleration to a given velocity.The acceleration of a rigid (...) body due to an applied impulse.Collisions between rigid bodies. (shrink)

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps, and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may (...) freely copy and distribute this work, as no entity has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

Given the long-standing controversy about whether the brain-dead should be considered alive in an irreversible coma or dead despite displaying apparent signs of life, the ethical and policy issues posed when family members insist on continued treatment are not as simple as commentators have claimed. In this article, we consider the kind of policy that should be adopted to manage a family's insistence that their brain-dead loved one continues to receive supportive care. We argue that while it would be ethically (...) inappropriate to continue to devote scarce acute care resources to such patients in a hospital setting, it may not be ethically inappropriate for patients to receive these resources in certain other settings. Thus, if a family insists on continuing to care for their brain-dead loved at their home, we should not, from a policy perspective, interfere with the family's wishes. We also argue that healthcare professionals should make some effort to facilitate the transfer of brain-dead patients to these other settings when families insist on continued treatment despite being informed about the lack of any potential for recovery of consciousness. Our arguments are strengthened by the fact that patients in a persistent vegetative state, who, when correctly diagnosed, also have no potential for recovery of consciousness, are routinely transferred from hospitals to nursing homes or long-term care facilities where they continue to be ventilated, tube fed and to receive other supportive care. We also briefly explore the question of who should be responsible for the costs of such treatment at the long-term care facility. (shrink)

Incomplete Archaeologies takes a familiar archaeological concept--assemblages--and reconsiders such groupings, collections and sets of things from the perspective of the work required to assemble them. The discussions presented here engage with the practices of collection, construction, performance and creation in the past (and present) which constitute the things and groups of things studied by archaeologists--and examine as well how these things and thing-groups are dismantled, rearranged, and even destroyed, only to be rebuilt and recreated. The ultimate aim is to reassert (...) an awareness of the incompleteness of assemblage, and thus the importance of practices of assembling (whether they seem at first creative or destructive) for understanding social life in the past as well as the present. The individual chapters represent critical engagements with this aim by archaeologists presenting a broad scope of case studies from Eurasia and the Mediterranean. Case studies include discussions of mortuary practice from numerous angles, the sociopolitics of metallurgy, human-animal relationships, landscape and memory, the assembly of political subjectivity and the curation of sovereignty. These studies emphasise the incomplete and ongoing nature of social action in the past, and stress the critical significance of a deeper understanding of formation processes as well as contextual archaeologies to practices of archaeology, museology, art history, and other related disciplines. Contributors challenge archaeologists and others to think past the objects in the assemblage to the practices of assembling, enabling us to consider not only plural modes of interacting with and perceiving things, spaces, human bodies and temporalities in the past, but also to perhaps discover alternate modes of framing these interactions and relationships in our analyses. Ultimately then, Incomplete Archaeologies takes aim at the perceived totality not only of assemblages of artefacts on shelves and desks, but also that of some of archaeology's seeming-seamless epistemological objects"--From publisher's website. (shrink)

T he nine papers of this Supplement on these significant issues and important ideas are closely accentuated and critically discussed by well-established specialists, philosophers and historians, from various relevant disciplines of study.

Cultural differences in the perception of geometric illusions. Science 139: 769- 71. Shepard, RN 1 99o. Mind sights. New York: Freeman & Co. ...

What is 'praxis'? How do we study theology from its perspective? These are the main questions which this book seeks to answer.

According to Quine’s indispensability argument, we ought to believe in just those mathematical entities that we quantify over in our best scientific theories. Quine’s criterion of ontological commitment is part of the standard indispensability argument. However, we suggest that a new indispensability argument can be run using Armstrong’s criterion of ontological commitment rather than Quine’s. According to Armstrong’s criterion, ‘to be is to be a truthmaker (or part of one)’. We supplement this criterion with our own brand of metaphysics, 'Aristotelian (...) realism', in order to identify the truthmakers of mathematics. We consider in particular as a case study the indispensability to physics of real analysis (the theory of the real numbers). We conclude that it is possible to run an indispensability argument without Quinean baggage. (shrink)

Classic rock of the 1960s and early 1970s broke away from the harmless bubblegum and surfing music of the 1950s to become a vehicle for profound commentary upon the human condition. Theories and motifs from major figures in the history of philosophy, theology and literature were refracted and transfigured in this intelligent new popular art form.

The Encyclopedia of Philosophy could state accurately in 1967: "Of all the major German philosophers, Schelling is the least known in the English-speaking world." A tentative survey discloses few articles and books on one who is casually ranked with Hegel. There is, in fact, not one book-length study in English on Schelling’s thought.

T he nine papers of this Supplement on these significant issues and important ideas are closely accentuated and critically discussed by well-established specialists, philosophers and historians, from various relevant disciplines of study.