Summary
How It Began: A Time Traveler's Guide to the Universe is a non-fiction book by astronomy professor Chris Impey on the origins of everything from the Moon to the universe. The finite speed of light and the vastness of space turn modern large telescopes into time machines and astronomers into armchair time travelers. Looking out in space is looking back in time. Each chapter has vignettes that place the reader in increasingly unfamiliar physical situations that are increasingly unfamiliar. How It Began has an associated web site containing source material on each major topic. [1]
The first third of the book deals with the proximate universe. The journey starts with the Moon and its formation from an impact with the infant Earth. Next stop is the outer Solar System and the amazing process by particles of dust grew into planets. The nearest star is the place where star formation is considered, followed by the Orion Nebula, where young stars are forming at a furious rate. [2] The last stop in the nearby universe is the center of our galaxy, site of a black hole four million times the mass of the Sun. [3]
The second third of the book examines the remote universe. Andromeda is seen as it was before humans evolved on the plains of Africa, and galaxies are all seen over time spans that dwarf our existence. The next stop is the massive Coma cluster of galaxies, a swarm of thousands of galaxies bound by invisible dark matter. This section continues with a visit to galaxies that created their stars long before the Earth formed and it finished with the time when stars first congealed out of gas in the expanding universe, 200 million years after the Big Bang. [4]
The last third of the book ventures into the alien universe. The microwave background radiation is a relic of time when stable atoms first formed and the "fog lifted" in the infant universe. [5] Reaching back to the time when the universe was as hot as the core of a star, the Big Bang is manifested in the creation of helium. The last chapters of the book cross into the realm of speculation, with descriptions the tiny asymmetry in the forces of nature that led to a tiny excess of matter over antimatter, the early exponential expansion that flattened space-time, and the idea of the universe as one quantum event among many.
The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the earliest known periods through its subsequent large-scale form. These models offer a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, and large-scale structure. The overall uniformity of the Universe, known as the flatness problem, is explained through cosmic inflation: a sudden and very rapid expansion of space during the earliest moments. However, physics currently lacks a widely accepted theory of quantum gravity that can successfully model the earliest conditions of the Big Bang.
A galaxy is a system of stars, stellar remnants, interstellar gas, dust, and dark matter bound together by gravity. The word is derived from the Greek galaxias (γαλαξίας), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. Galaxies, averaging an estimated 100 million stars, range in size from dwarfs with less than a hundred million stars, to the largest galaxies known – supergiants with one hundred trillion stars, each orbiting its galaxy's center of mass. Most of the mass in a typical galaxy is in the form of dark matter, with only a few percent of that mass visible in the form of stars and nebulae. Supermassive black holes are a common feature at the centres of galaxies.
The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the universe. According to this theory, space and time emerged together 13.787±0.020 billion years ago, and the universe has been expanding ever since the Big Bang. While the spatial size of the entire universe is unknown, it is possible to measure the size of the observable universe, which is approximately 93 billion light-years in diameter at the present day.
Astronomy is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroid, asteroid, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole.
A Brief History of Time: From the Big Bang to Black Holes is a book on theoretical cosmology by English physicist Stephen Hawking. It was first published in 1988. Hawking wrote the book for readers who had no prior knowledge of physics.
The timeline of the early universe outlines the formation and subsequent evolution of the Universe from the Big Bang to the present day. An epoch is a moment in time from which nature or situations change to such a degree that it marks the beginning of a new era or age.
Star Maker is a science fiction novel by British writer Olaf Stapledon, published in 1937. The book describes a history of life in the universe, dwarfing in scale Stapledon's previous book, Last and First Men (1930), a history of the human species over two billion years. Star Maker tackles philosophical themes such as the essence of life, of birth, decay and death, and the relationship between creation and creator. A pervading theme is that of progressive unity within and between different civilizations.
The abundance of the chemical elements is a measure of the occurrence of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by mass fraction, by mole fraction, or by volume fraction. Volume fraction is a common abundance measure in mixed gases such as planetary atmospheres, and is similar in value to molecular mole fraction for gas mixtures at relatively low densities and pressures, and ideal gas mixtures. Most abundance values in this article are given as mass fractions.
Big History is an academic discipline which examines history from the Big Bang to the present. Big History resists specialization, and searches for universal patterns or trends. It examines long time frames using a multidisciplinary approach based on combining numerous disciplines from science and the humanities, and explores human existence in the context of this bigger picture. It integrates studies of the cosmos, Earth, life, and humanity using empirical evidence to explore cause-and-effect relations, and is taught at universities and primary and secondary schools often using web-based interactive presentations.
The history of the Big Bang theory began with the Big Bang's development from observations and theoretical considerations. Much of the theoretical work in cosmology now involves extensions and refinements to the basic Big Bang model. The theory itself was originally formalised by Georges Lemaître in 1927. Hubble's Law of the expansion of the universe provided foundational support for the theory.
Cities in Flight is a four-volume series of science fiction novels and short stories by American writer James Blish, originally published between 1950 and 1962, which were first known collectively as the "Okie" novels. The series features entire cities that are able to fly through space using an anti-gravity device, the spindizzy. The stories cover roughly two thousand years, from the very near future to the end of the universe. One story, "Earthman, Come Home", won a Retro Hugo Award in 2004 for Best Novelette. Since 1970, the primary edition has been the omnibus volume first published in paperback by Avon Books. Over the years James Blish made many changes to these stories in response to points raised in letters from readers.
Christopher John Lintott is a British astrophysicist, author and broadcaster. He is a Professor of Astrophysics in the Department of Physics at the University of Oxford, and since 2023 is the Gresham Professor of Astronomy at Gresham College, London. Lintott is involved in a number of popular science projects aimed at bringing astronomy to a wider audience and is also the primary presenter of the BBC television series The Sky at Night, having previously been co-presenter with Patrick Moore until Moore's death in 2012. He co-authored Bang! – The Complete History of the Universe and The Cosmic Tourist with Moore and Queen guitarist and astrophysicist Brian May.
The Cosmic Calendar is a method to visualize the chronology of the universe, scaling its currently understood age of 13.8 billion years to a single year in order to help intuit it for pedagogical purposes in science education or popular science.
The Five Ages of the Universe is a popular science book written by Professor Fred Adams and Professor Gregory P. Laughlin about the future of an expanding universe first published in 1999.
Observations suggest that the expansion of the universe will continue forever. The prevailing theory is that the universe will cool as it expands, eventually becoming too cold to sustain life. For this reason, this future scenario once popularly called "Heat Death" is now known as the "Big Chill" or "Big Freeze".
The chronology of the universe describes the history and future of the universe according to Big Bang cosmology.
Wonders of the Universe is a 2011 television series produced by the BBC, Discovery Channel, and Science Channel, hosted by physicist Professor Brian Cox. Wonders of the Universe was first broadcast in the United Kingdom on BBC Two from 6 March 2011. The series comprises four episodes, each of which focuses on an aspect of the universe and features a 'wonder' relevant to the theme. It follows on from Cox's 2010 series for the BBC, Wonders of the Solar System. An accompanying book with the same title was also published.
Christopher David Impey is a British astronomer, educator, and author. He has been a faculty member at the University of Arizona since 1986. Impey has done research on observational cosmology, in particular low surface brightness galaxies, the intergalactic medium, and surveys of active galaxies and quasars. As an educator, he has pioneered the use of instructional technology for teaching science to undergraduate non-science majors. He has written many technical articles and a series of popular science books including The Living Cosmos, How It Began, How It Ends: From You to the Universe, Dreams of Other Worlds, and Humble Before the Void. He served as Vice-President of the American Astronomical Society, he is a Fellow of the American Association for the Advancement of Science, and a Howard Hughes Medical Institute Professor. He serves on the Advisory Council of METI.
The Living Cosmos: Our Search for Life in the Universe is a non-fiction book by the astronomer Chris Impey that discusses the subject of astrobiology and efforts to discover life beyond Earth. It was published as a hardcover by Random House in 2007 and as a paperback by Cambridge University Press in 2011.
Brief Answers to the Big Questions is a popular science book written by physicist Stephen Hawking, and published by Hodder & Stoughton (hardcover) and Bantam Books (paperback) on 16 October 2018. The book examines some of the universe's greatest mysteries, and promotes the view that science is very important in helping to solve problems on planet Earth. The publisher describes the book as "a selection of [Hawking's] most profound, accessible, and timely reflections from his personal archive", and is based on, according to a book reviewer, "half a million or so words" from his essays, lectures and keynote speeches.
