The Accelerating Expansion of the Universe


Book Description

11.3 billion years ago a star exploded. It is framed by the constellation Ursa Major. It was photographed in 1997 and it's impact on cosmology theory is still being felt. This exploding star is the Supernova 1997ff type Ia. The discovery and analysis of the radiation that emanates from SN 1997ff is providing support for the theory of "The Accelerating Expansion of our Universe," "Dark Matter," and "Dark Energy." The Hubble discovery also reveals that the universe only recently began speeding up, a discovery that suggests the universe is expanding more quickly than in the past, but there were alternate explanations. The accelerating expansion of the universe is the observation that the universe appears to be expanding at an increasing rate, so that the velocity at which a distant galaxy is receding from the observer is continuously increasing with time. The accelerated expansion was discovered in 1998, by two independent projects, the Supernova Cosmology Project and the High-Z Supernova Search Team, which both used distant type Ia supernovae as standard candles to measure the acceleration. The expansion of the universe is thought to have been accelerating since the universe entered its dark-energy-dominated era roughly 5 billion years ago. Within the framework of general relativity, an accelerating expansion can be accounted for by a positive value of the cosmological constant (Lambda), equivalent to the presence of a positive vacuum energy, dubbed "dark energy." While there are alternative possible explanations, the description assuming dark energy (positive Lambda) is used in the current standard model of cosmology, which also includes cold dark matter (CDM) and is known as the Lambda-CDM model. This book focuses on our Accelerating universe and the theories that support it.This book is designed to be a state of the art, superb academic reference work and provide an overview of the topic and give the reader a structured knowledge to familiarize yourself with the topic at the most affordable price possible. The accuracy and knowledge is of an international viewpoint as the edited articles represent the inputs of many knowledgeable individuals and some of the most current knowledge on the topic, based on the date of publication.




The Extravagant Universe


Book Description

The Extravagant Universe tells the story of a remarkable adventure of scientific discovery. One of the world's leading astronomers, Robert Kirshner, takes readers inside a lively research team on the quest that led them to an extraordinary cosmological discovery: the expansion of the universe is accelerating under the influence of a dark energy that makes space itself expand. In addition to sharing the story of this exciting discovery, Kirshner also brings the science up-to-date in a new epilogue. He explains how the idea of an accelerating universe--once a daring interpretation of sketchy data--is now the standard assumption in cosmology today. This measurement of dark energy--a quality of space itself that causes cosmic acceleration--points to a gaping hole in our understanding of fundamental physics. In 1917, Einstein proposed the "cosmological constant" to explain a static universe. When observations proved that the universe was expanding, he cast this early form of dark energy aside. But recent observations described first-hand in this book show that the cosmological constant--or something just like it--dominates the universe's mass and energy budget and determines its fate and shape. Warned by Einstein's blunder, and contradicted by the initial results of a competing research team, Kirshner and his colleagues were reluctant to accept their own result. But, convinced by evidence built on their hard-earned understanding of exploding stars, they announced their conclusion that the universe is accelerating in February 1998. Other lines of inquiry and parallel supernova research now support a new synthesis of a cosmos dominated by dark energy but also containing several forms of dark matter. We live in an extravagant universe with a surprising number of essential ingredients: the real universe we measure is not the simplest one we could imagine.




Conceptions of Cosmos


Book Description

This book is a historical account of how natural philosophers and scientists have endeavoured to understand the universe at large, first in a mythical and later in a scientific context. Starting with the creation stories of ancient Egypt and Mesopotamia, the book covers all the major events in theoretical and observational cosmology, from Aristotle's cosmos over the Copernican revolution to the discovery of the accelerating universe in the late 1990s. It presents cosmology as asubject including scientific as well as non-scientific dimensions, and tells the story of how it developed into a true science of the heavens. Contrary to most other books in the history of cosmology, it offers an integrated account of the development with emphasis on the modern Einsteinian andpost-Einsteinian period. Starting in the pre-literary era, it carries the story onwards to the early years of the 21st century.




The Accelerating Universe


Book Description

Advance Praise for The Accelerating Universe "The Accelerating Universe is not only an informative book about modern cosmology. It is rich storytelling and, above all, a celebration of the human mind in its quest for beauty in all things." —Alan Lightman, author of Einstein's Dreams "This is a wonderfully lucid account of the extraordinary discoveries that have made the last years a golden period for observational cosmology. But Mario Livio has not only given the reader one clear explanation after another of what astronomers are up to, he has used them to construct a provocative argument for the importance of aesthetics in the development of science and for the inseparability of science, art, and culture." —Lee Smolin, author of The Life of the Cosmos "What a pleasure to read! An exciting, simple account of the universe revealed by modern astronomy. Beautifully written, clearly presented, informed by scientific and philosophical insights." —John Bahcall, Institute for Advanced Study "A book with charm, beauty, elegance, and importance. As authoritative a journey as can be taken through modern cosmology." —Allan Sandage, Observatories of the Carnegie Institution of Washington




Expansion of the Universe


Book Description

The universe is a vast and enigmatic expanse, filled with countless mysteries that have intrigued scientists and philosophers for centuries. One of the most profound discoveries of modern cosmology is that the universe is not only expanding but doing so at an accelerating rate. This revelation has reshaped our understanding of the cosmos and introduced the concept of dark energy as a dominant force driving this acceleration. In this book, we embark on a journey through the history of cosmological thought, from the early observations that hinted at an expanding universe to the groundbreaking discoveries that revealed its acceleration. We will explore the role of the cosmological constant, a term introduced by Einstein in his equations of General Relativity, which has come to be associated with dark energy. We begin with a foundational understanding of the universe's expansion, delving into the Big Bang theory and the key observations that support it. From there, we examine the pivotal role of the cosmological constant and its implications for the structure and fate of the universe. As we navigate through the complexities of dark energy and its various theoretical models, we will also address the challenges and alternative theories that scientists are exploring to explain this cosmic acceleration. Finally, we will consider the future of cosmological research, highlighting the ongoing quests to unravel the mysteries that still elude us.




The Realm of the Nebulae


Book Description

No modern astronomer made a more profound contribution to our understanding of the cosmos than did Edwin Hubble, who first conclusively demonstrated that the universe is expanding. Basing his theory on the observation of the change in distanct galaxies, called red shift, Hubble showed that this is a Doppler effect, or alteration in the wavelength of light, resulting from the rapid motion of celestial objects away from Earth. In 1935, Hubble described his principal observations and conclusions in the Silliman lectures at Yale University. These lectures were published the following year as "The Realm of the Nebulae," which quickly became a classic work.




The Accelerating Universe


Book Description

Discovery of the accelerating Universe through Super Novae Ia observation about a decade ago has resulted in a paradigm shift in cosmological research. The present monograph is a consequence of theoretical investigation of dark energy, the agent supposed to be responsible for accelerating the Universe. Two main features of this work are Einstein's general relativistic approach and time-varying models of phenomenological character. It has been possible successfully to match the theoretical models with the observational data regarding the age of the Universe. Observational data of time variation of the gravitational constant G has been considered in the typical phenomenological models. Various time dependent equation of state parameter have been used to track the entire evolutionary period of the Universe. Possibility of a two-fluid Universe is also in the purview of this work. Another interesting side of this book is the visualization of the inflationary phase through analytic-graphical method and realization of the role of as dark energy in connection to cosmic string. In brief, Einstein's cosmological constant in its new face has resurfaced through this monograph.




The End of Everything


Book Description

Mack looks at five ways the universe could end, and the lessons each scenario reveals about the most important concepts in cosmology. --From publisher description.




How Old Is the Universe?


Book Description

"Tells the story of how astronomers solved one of the most compelling mysteries in science and, along the way, introduces readers to fundamental concepts and cutting-edge advances in modern astronomy"--From publisher description.