An astonishing exploration of planet formation and the origins of life by one of the world's most innovative planetary geologists. In 1959, the Soviet probe Luna 3 took the first photos of the far side of the moon. Even in their poor resolution, the images stunned scientists: the far side is an enormous mountainous expanse, not the vast lava-plains seen from Earth. Subsequent missions have confirmed this in much greater detail. How could this be, and what might it tell us about our own place in the universe? As it turns out, quite a lot. Fourteen billion years ago, the universe exploded into being, creating galaxies and stars. Planets formed out of the leftover dust and gas that coalesced into larger and larger bodies orbiting around each star. In a sort of heavenly survival of the fittest, planetary bodies smashed into each other until solar systems emerged. Curiously, instead of being relatively similar in terms of composition, the planets in our solar system, and the comets, asteroids, satellites and rings, are bewitchingly distinct. So, too, the halves of our moon. In When the Earth Had Two Moons, esteemed planetary geologist Erik Asphaug takes us on an exhilarating tour through the farthest reaches of time and our galaxy to find out why. Beautifully written and provocatively argued, When the Earth Had Two Moons is not only a mind-blowing astronomical tour but a profound inquiry into the nature of life here-and billions of miles from home.

This open access volume focuses on the cultural background of the pivotal transformations of scientific knowledge in the early modern period. It investigates the rich edition history of Johannes de Sacrobosco's Tractatus de sphaera, by far the most widely disseminated textbook on geocentric cosmology, from the unique standpoint of the many printers, publishers, and booksellers who steered this text from manuscript to print culture, and in doing so transformed it into an established platform of scientific learning. The corpus, constituted of 359 different editions featuring Sacrobosco's treatise on cosmology and astronomy printed between 1472 and 1650, represents the scientific European shared knowledge concerned with the cosmological worldview of the early modern period until far after the publication of Copernicus' De revolutionibus orbium coelestium in 1543. The contributions to this volume show how the academic book trade influenced the process of homogenization of scientific knowledge. They also describe the material infrastructure through which such knowledge was disseminated, and thus define the premises for the foundation of modern scientific communities.

Every scientific fact was born as an opinion about the unknown - a hypothesis. Opinion gradually becomes fact as evidence piles up to support a theory. But what if there are two theories, each of which has produced a myriad of things that correspond perfectly to the phenomena but can't be combined into one? One theory replaced the mystery of gravity with a precise model of space and time. The other theory replaced the mystery of matter with a description of quantum particles. As we understand our universe, we keep each in its own domain: space and time for very large things, particles for the very small ones. However, 13.8 billion years ago, those two incompatible domains belonged to a single realm. Who in the current or future generations of physicists will crack this seemingly impossible puzzle? This, contends the author, is not just a big question, but the biggest question in physics in our century. Combining Ickes's first-hand knowledge with a robust argument and intellectual playfulness, this fascinating book succeeds in making a notoriously difficult subject accessible to all readers interested in a better grasp of our universe.

Written by an international leader in the field, this is a coherent and accessible account of the concepts that are now vital for understanding cutting-edge work on supermassive black holes. These include accretion disc misalignment, disc breaking and tearing, chaotic accretion, the merging of binary supermassive holes, the demographics of supermassive black holes, and the defining effects of feedback on their host galaxies. The treatment is largely analytic and gives in-depth discussions of the underlying physics, including gas dynamics, ideal and non-ideal magnetohydrodynamics, force-free electrodynamics, accretion disc physics, and the properties of the Kerr metric. It stresses aspects where conventional assumptions may be inappropriate and encourages the reader to think critically about current models. This volume will be useful for graduate or Masters courses in astrophysics, and as a handbook for active researchers in the field. eBook formats include colour figures while print formats are greyscale only.

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.

In our small corner of the universe, we know how some matter behaves most of the time and what even less of it looks like, and we have some good guesses about where it all came from. But we really have no clue what's going on. In fact, we don't know what about 95% of the universe is made of. So what happens when a cartoonist and a physicist walk into this strange, mostly unknown universe? Jorge Cham and Daniel Whiteson gleefully explore the biggest unknowns, why these things are still mysteries, and what a lot of smart people are doing to figure out the answers (or at least ask the right questions). While they're at it, they helpfully demystify many complicated things we do know about, from quarks and neutrinos to gravitational waves and exploding black holes. With equal doses of humour and delight, they invite us to see the universe as a vast expanse of mostly uncharted territory that's still ours to explore. This is a book for fans of Brian Cox and What If. This highly entertaining highly illustrated book is perfect for anyone who's curious about all the great mysteries physicists are going to solve next.

We've all asked ourselves the question. It's impossible to look up at the stars and NOT think about it: Are we alone in the universe? Books, movies and television shows proliferate that attempt to answer this question and explore it. In OUT THERE Space.com senior writer Dr. Michael Wall treats that question as merely the beginning, touching off a wild ride of exploration into the final frontier. He considers, for instance, the myriad of questions that would arise once we do discover life beyond Earth (an eventuality which, top NASA officials told Wall, is only drawing closer). What would the first aliens we meet look like? Would they be little green men or mere microbes? Would they be found on a planet in our own solar system or orbiting a star far, far away? Would they intend to harm us, and if so, how might they do it? And might they already have visited? OUT THERE is arranged in a simple question-and-answer format. The answers are delivered in Dr. Wall's informal but informative style, which mixes in a healthy dose of humor and pop culture to make big ideas easier to swallow. Dr. Wall covers questions far beyond alien life, venturing into astronomy, physics, and the practical realities of what long-term life might be like for we mere humans in outer space, such as the idea of lunar colonies, and even economic implications. Readers won't just be hearing from Dr. Wall. As a longtime science journalist--whose work at Space.com is syndicated in outlets from Scientific American to Fox News--he has assembled an impressive array of contacts to provide expert commentary. From a former NASA chief scientist to leading science educators like Neil DeGrasse Tyson and Bill Nye to would-be space traveler Elon Musk, Dr. Wall shares the insights of some of the leading lights in space exploration today, and shows how the next space age might be brighter than ever.

The full inside story of the detection of gravitational waves at LIGO, one of the most ambitious feats in scientific history *Selected as a Book of the Year 2016 in the Sunday Times* 'This is empirical poetry. A fascinating tale of human curiosity beautifully told, and with black holes and lasers too' Robin Ince In 1916 Albert Einstein predicted the existence of gravitational waves: miniscule ripples in the very fabric of spacetime generated by unfathomably powerful events. If such vibrations could somehow be recorded, we could observe our universe for the first time through sound: the hissing of the Big Bang, the low tones of merging galaxies, the drumbeat of two black holes collapsing into one... In 2016 a team of hundreds of scientists at work on a billion-dollar experiment made history when they announced the first ever detection of a gravitational wave, confirming Einstein's prediction a century ago. Based on complete access to LIGO (Laser Interferometer Gravitational-Wave Observatory) and the scientists who created it, Black Hole Blues offers a first-hand account of this astonishing achievement: an intimate story of cutting-edge science at its most awe-inspiring and ambitious.

How would Saturn’s rings look from a spaceship sailing just above them? If you were falling into a black hole, what’s the last thing you’d see before your spaghettification? What would it be like to visit the faraway places we currently experience only through high-powered telescopes and robotic emissaries? Faster-than-light travel may never be invented, but we can still take the scenic route through the universe with renowned astronomer and science communicator Philip Plait. On this lively, immersive adventure through the cosmos, Plait draws ingeniously on the latest scientific research to transport readers to ten spectacular sites, from our own familiar Moon to the outer reaches of our solar system and far beyond. Whether strolling through a dust storm under Mars’ butterscotch sky, witnessing the birth of a star or getting dizzy in a technicolour nebula, Plait is an illuminating, entertaining guide to the most otherworldly views in our universe.

This timely volume provides comprehensive coverage of all aspects of cosmology and extragalactic astronomy at an advanced level. Beginning with an overview of the key observational results and necessary terminology, it covers important topics: the theory of galactic structure and galactic dynamics, structure formation, cosmic microwave background radiation, formation of luminous galaxies in the universe, intergalactic medium and active galactic nuclei. This self-contained text has a modular structure, and contains over one hundred worked exercises. It can be used alone, or in conjunction with the previous two accompanying volumes (Volume I: Astrophysical Processes, and Volume II: Stars and Stellar Systems).

That is merely surface reality. Beneath it lies the deeper reality which reveals itself when the mind is without any armour, when the heart opens up, and when reason becomes free from all sorts of cunningness and instrumentality. Only then does music touch us, and take us to the depths of our existence." The book is full of revelationsAZan intimate engagement with the freshness of the morning and the depth of the dark silent night.

This book provides a comprehensive and instructive coverage of particle physics in the early universe, in a logical way. It starts from the thermal history of the universe by investigating some of the main arguments such as Big Bang nucleosynthesis, the cosmic microwave background (CMB) and the inflation, before treating in details the direct and indirect detection of dark matter and then some aspects of the physics of neutrino. Following, it describes possible candidates for dark matter and its interactions. The book is targeted at theoretical physicists who deal with particle physics in the universe, dark matter detection and astrophysical constraints, and at particle physicists who are interested in models of inflation or reheating. This book offers also material for astrophysicists who work with quantum field theory computations. All that is useful to compute any physical process is included: mathematical tables, all the needed functions for the thermodynamics of early universe and Feynman rules. In light of this, this book acts as a crossroad between astrophysics, particle physics and cosmology.

This book begins with the question 'Who am I?' and immediately sets off in an astonishingly original direction. Why didn't anyone before Harding think of responding to this question like this? It's so obvious, once you see it. Harding presents a new vision of our place in the universe that uses the scientific method of looking to see what is true. It turns out that the truth about ourselves is not only true but also very good, and breathtakingly beautiful. We live in a sacred, many-layered, living universe - or rather it lives in us. Though it was completed in 1950, this book is still ahead of its time. One day it will surely be widely recognised for its greatness: its all-encompassing vision, its originality and freshness, its depth of insight, its wide-ranging knowledge, the clarity and poetry of its language, its humanity. It is a world-view not dependent on local culture or religion, but on universally verifiable facts. It is also a world-view that respects our manifest differences whilst celebrating our underlying unity - the unity not just of oneself with other people but with all of life, indeed with the whole universe. Harding died in 2007 aged 97, leaving behind him an impressive body of work. He was a highly creative person who was passionate about - he was in love with - this living universe and the immortal treasure that abides at its centre - at our centre. "A work of the highest genius." C. S. Lewis.

Covering the origins of life on Earth and our search for life elsewhere in the Universe, examining what life could look like, the ways scientists are looking for it and what we expect to find.

In CONSTELLATIONS, award-winning astronomy writer Govert Schilling takes us on an unprecedented visual tour of all 88 constellations in our night sky. Much more than just a stargazer's guide, CONSTELLATIONS is complete history of astronomy as told by Schilling through the lens of each constellation. The book is organized alphabetically by constellation. Profiles of each constellation include basic information such as size, visibility, and number of stars, as well as information on the discovery and naming of the constellation and associated lore. Beyond details about the constellation itself is information about every astronomical event that took place or discovery made in the vicinity of the constellation. In the constellation of Cygnus (the Swan) we encounter the location of the first confirmed black hole. A stop at Gemini (the Twins) is a chance to say hello to the dwarf planet Pluto, and in Orion (the hunter) we find the location of the first identified gamma-ray burst. Stunning star maps throughout the book by acclaimed star mapmaker Wil Tirion show us the exact location of every constellation, the details of its structure, as well as its surrounding astronomical neighbors.

Demonstrating the unity of Tolkien's created world across Middle-earth's Ages. An in-depth examination of the role of divine beings in Tolkien's work, Tolkien's Cosmology: Divine Beings and Middle-earth brings together Tolkien's many references to such beings and analyzes their involvement within his created world. Unlike many other commentators, Sam McBride asserts that a careful reading of the whole of the author's corpus shows a coherent, if sometimes contradictory, divine presence in the world.In The Silmarillion, an epic history of the First Age of Middle-earth, Tolkien describes the Ainur, angelic beings under the direction of Eru Iluvatar, the legendarium's god, as creators of physical reality. Some of these divine beings, the Valar and the Maiar, enter physical reality to oversee its development and prepare for the appearance of sentient life forms in Middle-earth: Elves and Humans, Dwarves, and eventually Hobbits. In the early stages of this history, the Valar and Maiar interact directly with Elves and Humans, opposing the work of evil beings led by Melkor. Yet Tolkien appears, at first glance, to have ignored this pantheon in The Hobbit and The Lord of the Rings, set in the Third Age of Middle-earth. Tolkien's letters, however, suggest the cosmological structure continues. And representatives of the Valar and Maiar can be seen at work, such as Gandalf and Saruman. Tolkien also introduces hints that his divine beings continue to influence events invisibly, as with the prominence of luck in The Hobbit and fortuitous weather conditions in The Lord of the Rings. In the end, McBride argues, Tolkien's cosmology allows room for everything from poor decision-making to evil, suffering, and death, all part of a belief system that will make the final victory of Good much more powerful.

**WINNER OF THE 2020 NOBEL PRIZE IN PHYSICS** What came before the Big Bang? How did the universe begin and must it inevitably end? In this remarkable book Roger Penrose brilliantly illuminates some of the deepest mysteries of the universe. Cycles of Time contains a penetrating analysis of the second law of thermodynamics - according to which the 'randomness' of our world is continually increasing - and a thorough examination of the light-cone geometry of space-time. It combines these two central themes to show how the expected ultimate fate of our accelerating, expanding universe can actually be reinterpreted as the 'big bang' of a new one. Presenting various standard and non-standard cosmological models, discussing black holes in depth as well as taking in the role of the cosmic microwave background along the way, Roger Penrose argues that the Big Bang was not actually the beginning of everything - nor will it signal the end. 'Science needs more people like Penrose, willing and able to point out the flaws in fashionable models from a position of authority, and to signpost alternative roads to follow' Independent

Applications of quantum field theoretical methods to gravitational physics, both in the semiclassical and the full quantum frameworks, require a careful formulation of the fundamental basis of quantum theory, with special attention to such important issues as renormalization, quantum theory of gauge theories, and especially effective action formalism. The first part of this graduate textbook provides both a conceptual and technical introduction to the theory of quantum fields. The presentation is consistent, starting from elements of group theory, classical fields, and moving on to the effective action formalism in general gauge theories. Compared to other existing books, the general formalism of renormalization in described in more detail, and special attention paid to gauge theories. This part can serve as a textbook for a one-semester introductory course in quantum field theory. In the second part, we discuss basic aspects of quantum field theory in curved space, and perturbative quantum gravity. More than half of Part II is written with a full exposition of details, and includes elaborated examples of simplest calculations. All chapters include exercises ranging from very simple ones to those requiring small original investigations. The selection of material of the second part is done using the "must-know" principle. This means we included detailed expositions of relatively simple techniques and calculations, expecting that the interested reader will be able to learn more advanced issues independently after working through the basic material, and completing the exercises.

Cometography is a multi-volume catalog of every comet observed throughout history. It uses the most reliable orbits known to determine the distances from the Earth and Sun at the time a comet was discovered and last observed, as well as the largest and smallest angular distance to the Sun, most northerly and southerly declination, closest distance to the Earth, and other details to enable the reader to understand the physical appearance of each well-observed comet. Volume 4 provides a complete discussion of each comet seen from 1933 to 1959. It includes physical descriptions made throughout each comet's apparition. The comets are listed in chronological order, and each listing includes complete references to publications relating to the comet. This book is the most complete and comprehensive collection of comet data available, and provides amateur and professional astronomers, and historians of science, with a definitive reference on comets through the ages.

In the sixth century BC, Anaximander of Miletus, an associate of Thales, initiated Western philosophy and science with a theory of how the world order arose, heavens and earth formed, and human beings came into existence. This book makes available a work that is of value for students in classics, philosophy, literature, and the history of science.

Since the dawn of humanity, men have attempted to divine the nature of the heavens. The first astronomers mapped the movement of the seasons and used the positions of the constellations for augurs and astrology. Today, the search goes ever deeper into the nature of reality and life itself. In this accessible overview, astrophysicist J.P. McEvoy tells the story of how our knowledge of the cosmos has developed. He puts in context many of the greatest discoveries of all time and many of the dominant personalities: Aristotle, Copernicus, and Isaac Newton, and as we approach the modern era, Einstein, Eddington, and Hawking.