What’s in the dark? Countless generations have gazed up at the night sky and asked this question—the same question that cosmologists ask themselves as they study the universe. The answer turns out to be surprising and rich. The space between stars is filled with an exotic substance called “dark matter” that exerts gravity but does not emit, absorb, or reflect light. The space between galaxies is rife with “dark energy” that creates a sort of cosmic antigravity causing the expansion of the universe to accelerate. Together, dark matter and dark energy account for 95 percent of the content of the universe. News reporters and science journalists routinely talk about these findings using terms that they assume we have a working knowledge of, but do you really understand how astronomers arrive at their findings or what it all means? Cosmologists face a conundrum: how can we study substances we cannot see, let alone manipulate? A powerful approach is to observe objects whose motion is influenced by gravity. Einstein predicted that gravity can act like a lens to bend light. Today we see hundreds of cases of this—instances where the gravity of a distant galaxy distorts our view of a more distant object, creating multiple images or spectacular arcs on the sky. Gravitational lensing is now a key part of the international quest to understand the invisible substance that surrounds us, penetrates us, and binds the universe together. A Ray of Light in a Sea of Dark Matter offers readers a concise, accessible explanation of how astronomers probe dark matter. Readers quickly gain an understanding of what might be out there, how scientists arrive at their findings, and why this research is important to us. Engaging and insightful, Charles Keeton gives everyone an opportunity to be an active learner and listener in our ever-expanding universe. Watch a video with Charles Keeton: Watch video now. (http://www.youtube.com/watch?v=Uc3byXNS1G0).

What's in the dark? Countless generations have gazed up at the night sky and asked this question--the same question that cosmologists ask themselves as they study the universe. The answer turns out to be surprising and rich. The space between stars is filled with an exotic substance called "dark matter" that exerts gravity but does not emit, absorb, or reflect light. The space between galaxies is rife with "dark energy" that creates a sort of cosmic antigravity causing the expansion of the universe to accelerate. Together, dark matter and dark energy account for 95 percent of the content of the universe. News reporters and science journalists routinely talk about these findings using terms that they assume we have a working knowledge of, but do you really understand how astronomers arrive at their findings or what it all means? Cosmologists face a conundrum: how can we study substances we cannot see, let alone manipulate? A powerful approach is to observe objects whose motion is influenced by gravity. Einstein predicted that gravity can act like a lens to bend light. Today we see hundreds of cases of this--instances where the gravity of a distant galaxy distorts our view of a more distant object, creating multiple images or spectacular arcs on the sky. Gravitational lensing is now a key part of the international quest to understand the invisible substance that surrounds us, penetrates us, and binds the universe together. A Ray of Light in a Sea of Dark Matter offers readers a concise, accessible explanation of how astronomers probe dark matter. Readers quickly gain an understanding of what might be out there, how scientists arrive at their findings, and why this research is important to us. Engaging and insightful, Charles Keeton gives everyone an opportunity to be an active learner and listener in our ever-expanding universe. Watch a video with Charles Keeton: Watch video now. (http: //www.youtube.com/watch'v=Uc3byXNS1G0).

January 1937. Clouds of war are gathering over a fogbound London. Twenty-eight year old Jack is poor, lonely and desperate to change his life. So when he's offered the chance to be the wireless operator on an Arctic expedition, he jumps at it. Spirits are high as the ship leaves Norway: five men and eight huskies, crossing the Barents Sea by the light of the midnight sun. At last they reach the remote, uninhabited bay where they will camp for the next year. Gruhuken. But the Arctic summer is brief. As night returns to claim the land, Jack feels a creeping unease. One by one, his companions are forced to leave. He faces a stark choice. Stay or go. Soon he will see the last of the sun, as the polar night engulfs the camp in months of darkness. Soon he will reach the point of no return - when the sea will freeze, making escape impossible. And Gruhuken is not uninhabited. Jack is not alone. Something walks there in the dark. This Special Edition Ebook will feature exclusive material: AUTHOR EXTRAS: Dark Matter ¿ An exclusive interview with Michelle Paver and an extended author biography with integrated photos of the landscape of Spitsbergen. COVER DESIGN: Dark Matter ¿ the jacket designer¿s take and cover design progression (5 x visuals). DARK MATTER - A SHORT FILM: Dark Matter ¿ Turning the novel into a short promotional film and Dark Matter - The Film Director's Cut, the rejected film scripts, the final film script and behind the scenes at filming (3 x visuals).

Pigeons The Theory of Everything is the true story of one mans quest to find meaning in what appears to be a meaningless world. The first part of the book is an examination of the intermittent new reels of Robert’s life that comprise his memories. These news reels are an eclectic mix of the splendor and wonder of nature juxtapose the horror and graphic violence that became Robert’s life. These stream of conscientiousness news reels are hauntingly beautiful and tragic. The middle of the book contains a dialog between Robert and his friend Dr. James Tenney. As Robert and James plumb the depths of human existence and knowledge something wonderful begins to happen. From the shattered fragments of Robert’s life and the intermittent news reels of his memories Robert begins to construct a beautiful mosaic. This mosaic of meaning and answers eventually exceeds Robert’s wildest dreams. Armed with this epiphany of answers Robert becomes obsessed with a new goal of completing the theory of everything, which is the “Holy Grail” of theoretical physics. With Pigeons The Theory of Everything Robert answers the central mysteries of theoretical physics as well as the central mysteries of human existence. If you have ever wondered if there is a God and what God is, this book is for you. If you have ever agonized over your own mortality and the possibility of not existing forever, this book is for you. If you have ever wondered if anyone would ever answer the ultimate questions of the cosmos and human existence, this book has the answers you are seeking.

Galileo Unbound traces the journey that brought us from Galileo's law of free fall to today's geneticists measuring evolutionary drift, entangled quantum particles moving among many worlds, and our lives as trajectories traversing a health space with thousands of dimensions. Remarkably, common themes persist that predict the evolution of species as readily as the orbits of planets or the collapse of stars into black holes. This book tells the history of spaces of expanding dimension and increasing abstraction and how they continue today to give new insight into the physics of complex systems. Galileo published the first modern law of motion, the Law of Fall, that was ideal and simple, laying the foundation upon which Newton built the first theory of dynamics. Early in the twentieth century, geometry became the cause of motion rather than the result when Einstein envisioned the fabric of space-time warped by mass and energy, forcing light rays to bend past the Sun. Possibly more radical was Feynman's dilemma of quantum particles taking all paths at once — setting the stage for the modern fields of quantum field theory and quantum computing. Yet as concepts of motion have evolved, one thing has remained constant, the need to track ever more complex changes and to capture their essence, to find patterns in the chaos as we try to predict and control our world.

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.

This book describes some of the frontier problems of cosmology: our almost total ignorance of what the Universe is made up of, the mystery of its origin and its end. The book starts with a description of the historical events that led to the construction of the Big Bang model together with the stages that transformed the Universe from a very hot place to a very cold one, full with the structures that we observe today. These structures (stars, galaxies, etc.) constitute only 5% of the contents of the Universe. Concerning the remaining 95%, dubbed dark matter and dark energy, we know very little, and we have only indirect evidence of their existence. The text describes the story and the protagonists who showed the need for the existence of this 'missing matter', the observations, and puzzles they had to solve to understand that dark matter was not ordinary matter. The book describes the hunt for dark matter, carried out with instruments operating in space, on the Earth's surface, and in laboratories built in the bowels of the Earth. It also describes dark energy, which manifests itself in the accelerated expansion of the Universe, and appeared only a few billions of years ago. The book discusses why dark energy must exist and what its existence implies, especially for the future and the end of our Universe.

Describes the dark matter problem in particle physics, astrophysics and cosmology for graduate students and researchers.

A fascinating and highly accessible treatment of the intriguing problem facing astronomers and cosmologists today: What is the universe made of, if only 50 percent of it can be accounted for by the luminous matter observable in galaxies?

Very-high-energy astrophysics studies the most energetic photons in the sky, allowing the exploration of violent and extreme non-thermal phenomena in the Universe. Significant advances in knowledge have been made in this field using ground-based imaging atmospheric Cherenkov telescopes (IACTs) as detectors, to study these physical processes in the Universe. This book reviews the progress in the field since the advent of the second generation IACTs around 2004. Going through the scientific highlights obtained by the three current instruments of this kind, H.E.S.S., MAGIC and VERITAS, operating now for more than 15 years, this book presents a state-of-the-art knowledge in four areas of modern astrophysics and cosmology, namely the origin of the cosmic rays, the physics of compact objects and their resulting relativistic outflows, gamma-ray cosmology, and the search for dark matter. Along with a detailed review of the outstanding scientific outcomes, a summary of the key technological developments that yielded the recognized success of the technique is also provided.This book is written for early-career academics in the fields of astrophysics, high energy physics and cosmology. At the same time, it can serve as a source of reference for the expert in the field.