What is a black hole? What is dark matter and what is it made of? How do scientists discover black holes and dark matter if they can't be seen? What do scientists know about these mysterious parts of the universe and what do they still hope to find out? Budding astronomers will learn the answers to these questions and more!
In a townhouse in Copenhagen works Hans Christian Andersen, a teller of exquisite and fantastic children's tales beloved by millions. But the true source of his stories dwells in his attic upstairs, her existence a dark secret kept from the outside world. Dangerous, twisted and funny, Martin McDonagh's new play travels deep into the abysses of the imagination. A Very Very Dark Matter premiered at the Bridge Theatre, London, in October 2018.
It is generally believed that most of the matter in the universe is dark, i.e. cannot be detected from the light which it emits (or fails to emit). Its presence is inferred indirectly from the motions of astronomical objects, specifically stellar, galactic, and galaxy cluster/supercluster observations. It is also required in order to enable gravity to amplify the small fluctuations in the cosmic microwave background enough to form the large-scale structures that we see in the universe today. For each of the stellar, galactic, and galaxy cluster/supercluster observations the basic principle is that if we measure velocities in some region, then there has to be enough mass there for gravity to stop all the objects flying apart. Dark matter has important consequences for the evolution of the universe and the structure within it. According to general relativity, the universe must conform to one of three possible types: open, flat, or closed. The total amount of mass and energy in the universe determines which of the three possibilities applies to the universe. In the case of an open universe, the total mass and energy density (denoted by the Greek letter Ù) is less than unity. If the universe is closed, Ù is greater than unity. For the case where Ù is exactly equal to one the universe is "flat". This new book details leading-edge research from around the globe.
Release on 2018-09-12 | by Abraao Jesse Capistrano
Author: Abraao Jesse Capistrano
Pubpsher: BoD – Books on Demand
The modern roots on the dark matter problem were basically launched in the 30s, with Zwicky's observations on a notorious discrepancy of mass in coma cluster that presented 500 times the mass than expected using the Newtonian theory (Virial theorem). Curiously, almost 90 years have passed, and the dark matter problem persists and is one of the most common challenges in both observational and theoretical physics. The Dark Matter is a rapid communication on the status-quo of the dark matter phenomenology as well as a presentation of new discussions on the theme.
Release on 2004 | by John N. Bahcall,Tsvi Piran,Steven Weinberg
Author: John N. Bahcall,Tsvi Piran,Steven Weinberg
Pubpsher: World Scientific
If standard gravitational theory is correct, then most of the matterin the universe is in an unidentified form which does not emit enoughlight to have been detected by current instrumentation. This book isthe second editon of the lectures given at the 4th Jerusalem WinterSchool for Theoretical Physics, with new material added. The lecturesare devoted to the missing matter problem in the universe, thesearch to understand dark matter. The goal of this volume is to makecurrent research work on unseen matter accessible to students withoutprior experience in this area and to provide insights for experts inrelated research fields. Due to the pedagogical nature of the originallectures and the intense discussions between the lecturers and thestudents, the written lectures included in this volume often containtechniques and explanations not found in more formal journalpublications.
Release on 2019-02-05 | by Philip T. Hoffman,Gilles Postel-Vinay,Jean-Laurent Rosenthal
The Development of Peer-to-Peer Lending and Banking in France
Author: Philip T. Hoffman,Gilles Postel-Vinay,Jean-Laurent Rosenthal
Pubpsher: Princeton University Press
Category: Business & Economics
How a vast network of shadow credit financed European growth long before the advent of banking Prevailing wisdom dictates that, without banks, countries would be mired in poverty. Yet somehow much of Europe managed to grow rich long before the diffusion of banks. Dark Matter Credit draws on centuries of cleverly collected loan data from France to reveal how credit abounded well before banks opened their doors. This incisive book shows how a vast system of shadow credit enabled nearly a third of French families to borrow in 1740, and by 1840 funded as much mortgage debt as the American banking system of the 1950s. Dark Matter Credit traces how this extensive private network outcompeted banks and thrived prior to World War I—not just in France but in Britain, Germany, and the United States—until killed off by government intervention after 1918. Overturning common assumptions about banks and economic growth, the book paints a revealing picture of an until-now hidden market of thousands of peer-to-peer loans made possible by a network of brokers who matched lenders with borrowers and certified the borrowers’ creditworthiness. A major work of scholarship, Dark Matter Credit challenges widespread misperceptions about French economic history, such as the notion that banks proliferated slowly, and the idea that financial innovation was hobbled by French law. By documenting how intermediaries in the shadow credit market devised effective financial instruments, this compelling book provides new insights into how countries can develop and thrive today.
This book is a new look at one of the hottest topics in contemporary science, Dark Matter. It is the pioneering text dedicated to sterile neutrinos as candidate particles for Dark Matter, challenging some of the standard assumptions which may be true for some Dark Matter candidates but not for all. So, this can be seen either as an introduction to a specialized topic or an out-of-the-box introduction to the field of Dark Matter in general. No matter if you are a theoretical particle physicist, an observational astronomer, or a ground based experimentalist, no matter if you are a grad student or an active researcher, you can benefit from this text, for a simple reason: a non-standard candidate for Dark Matter can teach you a lot about what we truly know about our standard picture of how the Universe works.
Release on 1990-03-31 | by D. Lynden-Bell,Gerry Gilmore
Author: D. Lynden-Bell,Gerry Gilmore
Pubpsher: Springer Science & Business Media
The visible universe is a small perturbation on the material universe. Zwicky and Sinclair Smith in the 1930s gave evidence of invisible mass in the Coma and Virgo Clusters of Galaxies. Better optical data has only served to confound their critics and the X-ray data confirms that the gravitational potentials are many times larger than those predicted on the basis of the observed stars. Dynamical analyses of individual galaxies have found that significant extra mass is needed to explain their rotational velocities. On much larger scales, tens of megaparsecs, there is suggestive evidence that there is even more mass per unit luminosity. What is this non-luminous stuff of which the universe is made'? How much of it is there? Need there be only one kind of stuff? There are three basic possi bili ties:- all of it is ordinary (baryonic) matter, all of it is some other kind of (non-baryonic) matter, or some of it is baryonic and some is non-baryonic.