Variability of Blazars

Variability of Blazars

Author: E. VALTAOJA (Ed)

Publisher: Cambridge University Press

Published: 1992

Total Pages: 484

ISBN-13: 9780521413510

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Blazars (also known as BL Lac objects), first discovered in 1978, are unusually energetic objects in the extragalactic universe. About 200 are known or suspected. They are radio sources with highly variable optical and radio emission, as well as high polarisation, and their optical spectra normally have no distinguishable features. It is generally accepted that they belong to that class of galaxies with active galactic nuclei, which are presumed to be driven by infall of matter to a supermassive black hole. In this book researchers give a complete summary of the observations of blazars and the theoretical interpretation. A comprehensive listing of confirmed and candidate objects is included. Mechanisms in which the variability can arise from shocks and relativistic jets are discussed. There are at least four different answers given to the question: what is a blazar? This book is a complete overview of the violent activity observed in these extreme active galactic nuclei.


The X-ray Background

The X-ray Background

Author: Xavier Barcons

Publisher: Cambridge University Press

Published: 1992-07-31

Total Pages: 328

ISBN-13: 9780521416511

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A review of the current observational knowledge and understanding of the cosmic X-ray background.


“The main Business of natural Philosophy”

“The main Business of natural Philosophy”

Author: Steffen Ducheyne

Publisher: Springer Science & Business Media

Published: 2011-10-20

Total Pages: 367

ISBN-13: 9400721269

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In this monograph, Steffen Ducheyne provides a historically detailed and systematically rich explication of Newton’s methodology. Throughout the pages of this book, it will be shown that Newton developed a complex natural-philosophical methodology which encompasses procedures to minimize inductive risk during the process of theory formation and which, thereby, surpasses a standard hypothetico-deductive methodological setting. Accordingly, it will be highlighted that the so-called ‘Newtonian Revolution’ was not restricted to the empirical and theoretical dimensions of science, but applied equally to the methodological dimension of science. Furthermore, it will be documented that Newton’s methodology was far from static and that it developed alongside with his scientific work. Attention will be paid not only to the successes of Newton’s innovative methodology, but equally to its tensions and limitations. Based on a thorough study of Newton’s extant manuscripts, this monograph will address and contextualize, inter alia, Newton’s causal realism, his views on action at a distance and space and time, the status of efficient causation in the /Principia/, the different phases of his methodology, his treatment of force and the constituents of the physico-mathematical models in the context of Book I of the /Principia/, the analytic part of the argument for universal gravitation, the meaning and significance of his regulae philosophandi, the methodological differences between his mechanical and optical work, and, finally, the interplay between Newton’s theology and his natural philosophy.


Science and Modern India: An Institutional History, c.1784-1947: Project of History of Science, Philosophy and Culture in Indian Civilization, Volume XV, Part 4

Science and Modern India: An Institutional History, c.1784-1947: Project of History of Science, Philosophy and Culture in Indian Civilization, Volume XV, Part 4

Author: Das Gupta

Publisher: Pearson Education India

Published: 1900

Total Pages: 1230

ISBN-13: 8131753751

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Science and Modern India: An Institutional History, c.1784-1947: Project of History of Science, Philosophy and Culture in Indian Civilization, Volume XV, Part 4 comprises chapters contributed by eminent scholars. It discusses the historical background of the establishment of science institutes that were established in pre-Independence India, and still exist, their functions and their present status. This volume discusses Indian science institutes that specialize in a particular field. It also delves into the area of engineering sciences.


Meteoroids

Meteoroids

Author: Galina O. Ryabova

Publisher: Cambridge University Press

Published: 2019-10-10

Total Pages: 321

ISBN-13: 1108683584

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This definitive guide provides advanced students and researchers with a detailed yet accessible overview of all of the central topics of meteor science. Leading figures from the field summarise their active research on themes ranging from the physical composition of meteoroids to the most recent optical and radar observations and ongoing theoretical developments. Crucial practical issues are also considered, such as the risk posed by meteoroids - to spacecraft, and on the ground - and future avenues of research are explored. Taking advantage of the latest dynamical models, insights are offered into meteor flight phenomena and the evolution of meteoroid streams and complexes, as well as describing the in-depth laboratory analysis of recovered material. The rapid rate of progress in twenty-first-century research makes this volume essential reading for anyone who wishes to understand how recent developments broaden our understanding of meteors, meteoroids and their origins.


A Philosophical Approach to MOND

A Philosophical Approach to MOND

Author: David Merritt

Publisher: Cambridge University Press

Published: 2020-04-30

Total Pages: 285

ISBN-13: 1108665683

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Dark matter is a fundamental component of the standard cosmological model, but in spite of four decades of increasingly sensitive searches, no-one has yet detected a single dark-matter particle in the laboratory. An alternative cosmological paradigm exists: MOND (Modified Newtonian Dynamics). Observations explained in the standard model by postulating dark matter are described in MOND by proposing a modification of Newton's laws of motion. Both MOND and the standard model have had successes and failures – but only MOND has repeatedly predicted observational facts in advance of their discovery. In this volume, David Merritt outlines why such predictions are considered by many philosophers of science to be the 'gold standard' when it comes to judging a theory's validity. In a world where the standard model receives most attention, the author applies criteria from the philosophy of science to assess, in a systematic way, the viability of this alternative cosmological paradigm.