This is the ideal resource for beginners and experienced stargazers in the United States and Canada, and has been updated to include new and practical information covering events occurring in North America's night sky throughout 2021. This practical guide is both an easy introduction to astronomy and a useful reference for seasoned stargazers. Now includes a section on comets and a map of the moon. Designed specifically for North America. Written and illustrated by astronomical experts, Storm Dunlop and Wil Tirion, and approved by the astronomers of the Royal Observatory Greenwich. Content includes: * Advice on where to start looking. * Easy-to-use star maps for each month with descriptions of what to see. * Positions of the moon and visible planets. * Details of objects and events in 2021. * Now in three editions: Britain and Ireland; North America; Southern Hemisphere.

Was there a beginning of time? Could time run backwards? Is the universe infinite or does it have boundaries? These are just some of the questions considered in the internationally acclaimed masterpiece by the world renowned physicist - generally considered to have been one of the world's greatest thinkers. It begins by reviewing the great theories of the cosmos from Newton to Einstein, before delving into the secrets which still lie at the heart of space and time, from the Big Bang to black holes, via spiral galaxies and strong theory. To this day A Brief History of Time remains a staple of the scientific canon, and its succinct and clear language continues to introduce millions to the universe and its wonders. This new edition includes recent updates from Stephen Hawking with his latest thoughts about the No Boundary Proposal and offers new information about dark energy, the information paradox, eternal inflation, the microwave background radiation observations, and the discovery of gravitational waves. It was published in tandem with the app, Stephen Hawking's Pocket Universe.

This book discusses analogies between relativistic cosmology and various physical systems or phenomena, mostly in the earth sciences, that are described formally by the same equations. Of the two independent equations describing the universe as a whole, one (the Friedmann equation) has the form of an energy conservation equation for one-dimensional motion. The second equation is fairly easy to satisfy (although not automatic): as a result, cosmology lends itself to analogies with several systems. Given that a variety of universes are mathematically possible, several analogies exist. Analogies discussed in this book include equilibrium beach profiles, glacial valleys, the shapes of glaciers, heating/cooling models, freezing bodies of water, capillary fluids, Omori's law for earthquake aftershocks, lava flows, and a few mathematical analogies (Fibonacci's sequence, logistic equation, geodesics of various spaces, and classic variational problems). A century of research in cosmology can solve problems on the other side of an analogy, which in turn can suggest ideas in gravity. Finding a cosmic analogy solves the inverse variational problem of finding a Lagrangian and a Hamiltonian for that system, when nobody thought one exists. Often, the symmetries of the cosmological equations translate in new symmetries of the analogous system. The book surprises the reader with analogies between natural systems and exotic systems such as possible universes.

Today we know much about the sky: how stars are born, how they live and die, and how the universe as a whole evolves. We have learned of the existence of another type of matter, indifferent to light and yet decisive for the formation of galaxies, and we have a hint of a dark energy that since the last 4.5 billion years has taken over the control of the cosmos. We postulated and then discovered and even photographed black holes and listened to the faint rustle of the space-time ripple produced when these monsters devour each other. We reached these astonishing results (recognized by a bunch of Nobel Prizes and filling every day the media with wonders for the eyes and the mind) by the marriage of physics and astronomy that unified the Earth with the sky and then by the leap forward of science and technology in the Twentieth Century. This rich heritage has ancient roots. It was built by accumulating discoveries with errors, observations with fantasies, myths, and superstitions with flashes of genius, over a span of millennia, since Homo sapiens, turning his eyes to the immutable and perfect sky, began to ask questions.The book is a narration of the answers to these questions that had evolved over time: a progressive path, inserted in the general history, with some second thoughts and many obstacles. This is a saga of men and machines where greatness sometimes mixes with misery and passion often borders on sacrifice and even martyrdom. Why should we know it? Because our current knowledge is the result of these efforts and of the preconceptions that accompanied them.The challenge has been to present this complex and intricate subject without resorting to any formulas, so that it can be accessible to a wide audience of curious people, including high school and university students and in general all those who normally keep themselves informed of scientific things. A rich bibliography has also been added in the appendix for those wishing to learn more on one or more topics.

Can you spot the Big Dipper in the night sky? Or Orion's Belt? Or Cassiopeia? Even in cities, and without the aid of a telescope, these are a few of the easier constellations to find. In fact, a great deal can be seen in the night sky with the naked eye - if you know what you're looking for. Night Sky presents 200 colour photographs of stunning nocturnal vistas all visible to the naked eye. From the majesty of the Northern Lights (Aurora borealis) as seen from Norway or Canada, and the Southern Lights (Aurora australis) as seen from Australia, to seeing the clarity of the Milky Way over an Italian forest, from witnessing a lunar eclipse in Indonesia to charting the course of the International Space Station across the Indian night, and from seeing a Geminid meteor shower in New Mexico to recognizing the Great Bear (Ursa Major) constellation over New England, the book is a feast of nocturnal delights. Where necessary, additional inset photographs indicate the formation of a constellation. Presented in a landscape format and with 200 outstanding colour photographs supported by fascinating captions, Night Sky is a stunning collection of images.

What does it take to consider a planet potentially habitable? If a planet is suitable for life, could life be present? Is life on other planets inevitable? Searching for Habitable Worlds answers these questions and provides both the general public and astronomy enthusiasts with a richly illustrated discussion of the most current knowledge regarding the search for extrasolar planets. Nearly everyone wants to know if we are alone in the universe. This book might not have the answers, but shows where we should look. This book is a fun and accessible book for everyone from middle schoolers to amateur astronomers of all ages. The use of non-technical language and abundant illustrations make this a quick read to inform everyone about the latest movement in the search for other planets that we might be able to inhabit. After a brief discussion on why humans are hard-wired to be curious, and to explore the unknown, the book describes what extrasolar planets are, how to detect them, and how to pin down potential targets. In addition, a data-driven list of the best candidates for habitability is profiled and the next generation of exoplanet-hunting scientific instruments and probes are identified.