Helge Kragh

Bio: Helge Kragh is an academic researcher from University of Copenhagen. The author has contributed to research in topics: Cosmology & Big Bang. The author has an hindex of 21, co-authored 107 publications receiving 1855 citations. Previous affiliations of Helge Kragh include Aarhus University & Niels Bohr Institute.

An Introduction to the Historiography of Science

Abstract: This book introduces the methodological and philosophical problems with which modern history of science is concerned, offering a comprehensive and critical review through description and evaluation of significant historiographical viewpoints. Incorporating discussion of key problems in general historical writing, with examples drawn from a range of disciplines, this non-elementary introduction bridges the gap between general history and history of science. Following a review of the early development of the history of science, the theory of history as applied to science history is introduced, examining the basic problems which this generates, including problems of periodisation, ideological functions, and the conflict between diachronical and anachronical historiography. Finally, the book considers the critical use, and analysis, of historical sources, and the possibility of the experiemental reconstruction of history. Aimed primarily at students, the book's broad scope and integration of historical, philosophical and scientific matters will interest philosophers, sociologists and general historians, for whom there is no alternative introduction to the subject at this level.

Dirac: A Scientific Biography

Abstract: Preface 1. Early years 2. Discovery of quantum mechanics 3. Relativity and spinning electrons 4. Travels and thinking 5. The dream of philosophers 6. Quanta and fields 7. Fifty years of a physicist's life 8. 'The so-called quantum electrodynamics' 9. Electrons and ether 10. Just a disappointment 11. Adventures in cosmology 12. The purest soul 13. Philosophy in physics 14. The principle of mathematical beauty Appendices Bibliography of P. A. M. Dirac Notes and references General bibliography Index of names Index of subjects.

Cosmology and Controversy: The Historical Development of Two Theories of the Universe

Abstract: For over three millennia, most people could understand the universe only in terms of myth, religion, and philosophy. Between 1920 and 1970, cosmology transformed into a branch of physics. With this remarkably rapid change came a theory that would finally lend empirical support to many long-held beliefs about the origins and development of the entire universe: the theory of the big bang. In this book, Helge Kragh presents the development of scientific cosmology for the first time as a historical event, one that embroiled many famous scientists in a controversy over the very notion of an evolving universe with a beginning in time. In rich detail he examines how the big-bang theory drew inspiration from and eventually triumphed over rival views, mainly the steady-state theory and its concept of a stationary universe of infinite age. In the 1920s, Alexander Friedmann and Georges Lemaitre showed that Einstein's general relativity equations possessed solutions for a universe expanding in time. Kragh follows the story from here, showing how the big-bang theory evolved, from Edwin Hubble's observation that most galaxies are receding from us, to the discovery of the cosmic microwave background radiation. Sir Fred Hoyle proposed instead the steady-state theory, a model of dynamic equilibrium involving the continuous creation of matter throughout the universe. Although today it is generally accepted that the universe started some ten billion years ago in a big bang, any readers may not fully realize that this standard view owed much of its formation to the steady-state theory. By exploring the similarities and tensions between the theories , Kragh provides the reader with indispensable background for understanding much of today's commentary about our universe.

Simulating physics with computers

Abstract: This chapter describes the possibility of simulating physics in the classical approximation, a thing which is usually described by local differential equations. But the physical world is quantum mechanical, and therefore the proper problem is the simulation of quantum physics. A computer which will give the same probabilities as the quantum system does. The present theory of physics allows space to go down into infinitesimal distances, wavelengths to get infinitely great, terms to be summed in infinite order, and so forth; and therefore, if this proposition is right, physical law is wrong. Quantum theory and quantizing is a very specific type of theory. The chapter talks about the possibility that there is to be an exact simulation, that the computer will do exactly the same as nature. There are interesting philosophical questions about reasoning, and relationship, observation, and measurement and so on, which computers have stimulated people to think about anew, with new types of thinking.

Stanford Encyclopedia of Philosophy

Abstract: Evolutionary psychology is one of many biologically informed approaches to the study of human behavior. Along with cognitive psychologists, evolutionary psychologists propose that much, if not all, of our behavior can be explained by appeal to internal psychological mechanisms. What distinguishes evolutionary psychologists from many cognitive psychologists is the proposal that the relevant internal mechanisms are adaptations—products of natural selection—that helped our ancestors get around the world, survive and reproduce. To understand the central claims of evolutionary psychology we require an understanding of some key concepts in evolutionary biology, cognitive psychology, philosophy of science and philosophy of mind. Philosophers are interested in evolutionary psychology for a number of reasons. For philosophers of science —mostly philosophers of biology—evolutionary psychology provides a critical target. There is a broad consensus among philosophers of science that evolutionary psychology is a deeply flawed enterprise. For philosophers of mind and cognitive science evolutionary psychology has been a source of empirical hypotheses about cognitive architecture and specific components of that architecture. Philosophers of mind are also critical of evolutionary psychology but their criticisms are not as all-encompassing as those presented by philosophers of biology. Evolutionary psychology is also invoked by philosophers interested in moral psychology both as a source of empirical hypotheses and as a critical target.

Principles Of Optics Electromagnetic Theory Of Propagation Interference And Diffraction Of Light

Abstract: Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

A Complete Bibliography of Publications in Isis, 2000{2009

Abstract: accademiche [38]. Ada [45]. Adrian [45]. African [56]. Age [39, 49, 61]. Al [23]. Al-Rawi [23]. Aldous [68]. Alex [15]. Allure [46]. America [60, 66]. American [49, 69, 61, 52]. ancienne [25]. Andreas [28]. Angela [42]. Animals [16]. Ann [26]. Anna [19, 47]. Annotated [46]. Annotations [28]. Anti [37]. Anti-Copernican [37]. Antibiotic [64]. Anxiety [51]. Apocalyptic [61]. Archaeology [26]. Ark [36]. Artisan [32]. Asylum [48]. Atri [54]. Audra [65]. Australia [41]. Authorship [15]. Axelle [29].

History of dark matter

Abstract: Although dark matter is a central element of modern cosmology, the history of how it became accepted as part of the dominant paradigm is often ignored or condensed into an anecdotal account focused around the work of a few pioneering scientists. The aim of this review is to provide a broader historical perspective on the observational discoveries and the theoretical arguments that led the scientific community to adopt dark matter as an essential part of the standard cosmological model.