This newly expanded and thoroughly updated third edition examines accretion as a source of energy in both binary star systems containing compact objects, and in active galactic nuclei. Assuming a basic knowledge of physics, the authors describe the physical processes at work in accretion discs and other accretion flows. New material includes a detailed treatment of disc instabilities, irradiated discs, disc warping, and general accretion flows. The treatment is suitable for advanced undergraduates, graduate students and researchers.
This book focuses on the cosmological implications of the gauge theories of particle physics and of string theory. It first examines relics of early phase transitions, more generic relics (baryons, neutrinos, axions), and supersymmetric particles (neutralinos and gravitinos). The author next studies supersymmetric theory, supergravity theory, and the constraints on the underlying field theory of the universe's inflationary era. The book concludes with a discussion of black hole solutions of the supergravity theory that approximates string theory at low energies and the insight that string theory affords into the microscopic origin of the Bekenstein-Hawking entropy.
Hidden from human view, accessible only to sensitive receivers attached to huge radio telescopes, giant versions of backyard satellite dishes, the invisible universe beyond our senses continues to fascinate and intrigue our imaginations. We cannot really comprehend what it means to say that a galaxy is exploding, yet that is the nature of some of the distant radio sources in the furthest reaches of space. Closer to home, in the Milky Way galaxy, radio astronomers listen patiently to the ticking of pulsars that tell of star death and states of matter of awesome densities. And between the stars, radio emission from a host of over 120 complex molecules radiate outward to reveal a tale about chemical processes that produce the very stuff of life. And all of this happens out there in the universe hidden from our eyes, even when aided by the Hubble Space Telescope.
Cosmologists yearn to behold the unseen elements of our universe. And as new technologies become more powerful and precise, scientists are getting their wish - though these tools are challenging the limits of our imagination as fast as they are answering many long standing questions.
Space is one of the last great frontiers for modern man. A never-ending source of investigation and inspiration, it beckons to scientists with an irresistible siren's call. And in this glorious age of cosmology, astronomical measurement has never been more precise. The power provided to us by extraordinary new observational mechanisms has shattered former suppositions and stimulated exciting new visions of the universe.
Only a few hundred years ago, the idea of Earth’s centrality and the reliance on supernatural beings were shattered. During the Renaissance, humans began to inquire more critically about themselves and the Universe. They realized that thinking about Nature was no longer sufficient. Looking at it was also necessary. Experiments became a central part of the process of inquiry. To be effective, ideas had to be tested experimentally, either to refine them if data favored them or to reject them if they did not. The “scientific method” was born— probably the most powerful technique ever conceived for the advancement of factual information. Modern science had arrived.
Do a little armchair time-travel, rub elbows with a four-dimensional intelligent life form, or stretch your mind to the furthest corner of an uncharted universe. With this astonishing guidebook, Surfing Through Hyperspace, you need not be a mathematician or an astrophysicist to explore the all-but-unfathomable concepts of hyperspace and higher-dimensional geometry. No subject in mathematics has intrigued both children and adults as much as the idea of a fourth dimension. Philosophers and parapsychologists have meditated on this mysterious space that no one can point to but may be all around us. Yet this extra dimension has a very real, practical value to mathematicians and physicists who use it every day in their calculations. In the tradtion of Flatland, and with an infectious enthusiasm, Clifford Pickover tackles the problems inherent in our 3-D brains trying to visualize a 4-D world, muses on the religious implications of the existence of higher-dimensional consciousness, and urges all curious readers to venture into "the unexplored territory lying beyond the prison of the obvious." Pickover alternates sections that explain the science of hyperspace with sections that dramatize mind-expanding concepts through a fictional dialogue between two futuristic FBI agents who dabble in the fourth dimension as a matter of national security. This highly accessible and entertaining approach turns an intimidating subject into a scientific game open to all dreamers. Surfing Through Hyperspace concludes with a number of puzzles, computer experiments and formulas for further exploration, inviting readers to extend their minds across this inexhaustibly intriguing scientific terrain.
Fred Hoyle was one of the most widely acclaimed and colourful scientists of the twentieth century, a down-to-earth Yorkshireman who combined a brilliant scientific mind with a relish for communication and controversy.
The novel was written by renowned physicist Steven Weinberg, a physicist at the University of Texas at Austin, whose research and breakthroughs in relation to electromagnetism led to him being awarded the 1979 Nobel Peace Prize in Physics. Weinberg is widely respected within the scientific and "lay" community alike, as his book allowed the common person to understand the creation of the universe and as such, his book is now translated in over 25 different languages.
What star is that? Where is the Southern Cross? Who was Orion? Answering these questions and many more, this book will become an essential traveling companion for amateur astronomers heading abroad. Its unique simplified maps make it easy to find the constellations in the southern hemisphere skies, and the stars within them.
Knowledge of our Universe has grown explosively over the past few decades, with discoveries of cometary objects in the far reaches of our Solar System, new-found planets around other stars, detections of powerful gamma ray bursts, galaxies in the process of formation in the infant Universe, and evidence of a mysterious force that appears to be accelerating the expansion of the Universe. From exotic black holes to the microwave background, the modern understanding of our larger cosmological home could barely be imagined just a generation ago. Headlines exclaim astonishing properties for astronomical objects – stars with densities equivalent to the mass of the sun compressed to the size of a city, million degree gas temperatures, energy sources of incredible power, and luminosities as great as an entire galaxy from a single dying star.
|« Март 2017 »|