Many Worlds in One The Search for Other Universes

Alex Vilenkin

Hill and Wang



Trade Paperback

248 Pages



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Among his peers, Alex Vilenkin is regarded as one of the most imaginative and creative cosmologists of our time. His contributions to our current understanding of the universe include a number of novel ideas, two of which—eternal cosmic inflation and the quantum creation of the universe from nothing—have provided a scientific foundation for the possible existence of multiple universes. With this book—his first for the general reader—Vilenkin joins another select group: the handful of first-rank scientists who are adept at explaining their work to non-specialists. With engaging, well-paced story-telling, a droll sense of humor, and a generous sprinkling of helpful cartoons, he conjures up a bizarre and fascinating new worldview that—to paraphrase Niels Bohr—might just be crazy enough to be true. In setting his course for Many Worlds in One, Vilenkin wrote: "The intended reader of this book is someone who, looking upward at the starry sky, occasionally wonders where it all came from, and how our little Earth and our civilization fit into the grand scheme of things. My goal is to tell this reader about a new picture of the universe—initially resisted by the vast majority of physicists—that has gradually emerged over the past two decades and is now becoming the accepted cosmological paradigm. I will try to make the book easy to read and maximally entertaining, using the story of my personal quest as a backdrop for discussion of the scientific ideas."


Praise for Many Worlds in One

“Vilenkin discusses the big bang and goes on to pose many far-reaching ideas, including his theory that the universe as we know it is just one of an infinite number of other universes. Good for readers who like Stephen Hawking and concise treatment of ultimate questions.”—Donna Marchetti, The Plain Dealer (Cleveland)

“Sprinkled with funny anecdotes, [Many Worlds in One] is a view from the front line, and will leave even a beginner with a deep understanding of the cosmos.  The book ends with a fantastically intriguing question sure to deprive you of sleep.”—Amanda Gefter, New Scientist Space

“In Many Worlds in One, Vilenkin offers an engaging personalized tour of cosmology, sharing his intimate view of developments in the field over the past quarter century. Cosmologists have a daily urge to explore in ways that sometimes seem to take them beyond the edge of practical common sense, but by clearly explaining what they are thinking and why, Vilenkin makes it possible for the reader to accompany them. He enlivens the scientific narrative by including colorful sketches of friends, colleagues and the heroic figures of earlier generations. Indeed, the book recalls the informal, lighthearted, inviting style of popular book by another Russian émgiré physicist, George Gamow, who introduced the ideas of the Big Bang to a broad readership half a century ago.”—Craig J. Hogan, American Scientist

“Vilenkin’s Many Worlds in One is a beautifully written story of a new worldview that has developed during the past 25 years. Cosmologists associate this view with the concept of an eternally inflating multiverse. String theorists, who joined in on the discussions a few years ago, call it the string theory landscape. The new paradigm replaces the idea of a single uniform universe with that of a multiverse consisting of many different universes with different properties. Vilenkin is one of the world’s leading theoretical cosmologists. He is in the inventor of the theory of cosmic strings, the author of several influential works on quantum creation of the universe, and one of the architects of the theory of eternal inflation . . . Vilenkin’s books are wonderful . . . It is impossible to write about inflationary theory and quantum cosmology without introducing some of the technical details. In less experienced hands, this could easily make such a book dry and intimidating. Fortunately, because of his deep understanding of the subject, Vilenkin successfully presents even the most complicated parts of the theory in a simple and intuitive way, and he does it without making any parts of his discussion vague or inaccurate—a real achievement. Vilenkin also offers personal recollection and a well-balanced narrative of the history of the most interesting cosmological ideas of the 20th century. I found his discussion of the work of Russian cosmologists refreshing, particularly concerning Alexei Starobinsky and Viatcheslav Mukhanov, whose seminal contribution to the development of inflationary cosmology is underappreciated by the English-reading audience. But what I like most about Many Worlds in One is its combination of Vilenkin’s seriousness, intellectual honesty, and good sense of humor. When I opened the book, I did not expect that it would be so much fun to read. If you are not sure whether this book is for you, I recommend doing something that goes against the grain: First read the prologue, then the epilogue, and then, if you are intrigued, the rest of the book. If you are among those who want to learn about the emerging worldview and enjoy intellectual challenges, you are in for a real treat.”—Andrei Linde, Physics Today

“Beginning with the question of the origin of the universe, the reader is introduced to the story of the big bang, that is, what the author calls the ‘science of creation.’ From there the reader is next introduced to Einstein’s general theory of relativity. Gravity, the distribution of matter in the universe, and the speed of light quickly follow—all key elements of the book. These topics are addressed clearly, often aided by pictures, graphs and diagrams. The book covers the major theories that address the origin of the universe. It does a fine job of explaining big bang, steady state, string theory and wormholes, to name just a few theories. Many Worlds in One is a good example of an astrophysics book. It is a fine rendition of this ‘genre,’ as this serves the physics-minded, that is, how physicists construe the universe today, this volume constitutes a competent, professional and very worthy work. Of this there can be very little doubt. This is no surprise. Vilenkin is one of the world’s leading theoretical cosmologists. He has made seminal contributions to the theory cosmological inflation, the idea that the universe may contain topological remnants from particle physics phase transitions, to quantum cosmology, and to many other central topics. Perhaps most importantly for the ideas in his book, he has been an architect of the idea of eternal inflation, and one of the primary researchers embracing its implications for the anthropic principle . . . A well-founded dissertation on universes.”—David F. Mota, Mathematical Reviews

"A wonderful tour of modern cosmology, wittily directed by one of the most gifted practitioners of the field. A pleasure to read."—Mario Livio, Senior Scientist, Space Telescope Science Institute, and author of The Equation That Couldn’t Be Solved

"Alex Vilenkin mines the subtlest phenomena shaping the cosmos to derive the grandest consequences. This is remarkable stuff—fantastic and moving in its implications—yet it is neither fantasy nor science fiction. Vilenkin's portrait of the cosmos points to the logical possibility of a multiplicity of universes, events and lives, and leads us to wonder about our own significance in this sea of infinite possibility."—Janna Levin, author of How the Universe Got Its Spots

"Alex Vilenkin's Many Worlds in One is one of the best science books I have ever read. Not only is Vilenkin one of the great pioneers in the subject of modern cosmology, but also he is exceptionally clear, wonderfully witty, and frequently full of wisdom."—Leonard Susskind, author of The Cosmic Landscape

"Can it really be that our universe is just one of many? Alex Vilenkin is your amiable, but authoritative and completely serious guide to this audacious idea at the frontier of cosmological science. He makes astonishing thoughts sound like sensible steps forward in an earnest enterprise. Many Worlds in One will open your mind to exponentially expanding universes that may lie just beyond our own."—Robert P. Kirshner, author of The Extravagant Universe

“Cosmology has moved from establishing that there was a finite start to the cosmos to theorizing about the initial conditions that kicked off the whole shebang. Vilenkin is a leading theorist whose scenarios about the enigma of the big bang emerge in this estimably clear, personable treatment. Vilenkin explains the idea of inflation, a phenomenal increase in the volume of space in the first infinitesimals of time, propounded by physicist Alan Guth. Inflation solved some theoretical problems but left others dangling, such as inducing inflation to stop; if it didn't, life could not have begun. Explaining that his solutions to the ‘graceful exit problem,’ as it is whimsically called, involve the concept of ‘eternal inflation,’ Vilenkin guides readers through its bizarre and head-spinning propositions. One is that our observed universe is embedded in a suprauniverse that infinitely spawns an infinite number of other universes. This and other gigantic ideas concisely presented will provoke the interest of readers intrigued by the origin of the big bang.”—Gilbert Taylor, Booklist

"Cosmologists ask many difficult questions and often come up with strange answers. In this engagingly written . . . book, Vilenkin, a Tufts University physicist, does exactly this, discussing the creation of the universe, its likely demise and the growing belief among cosmologists that there are an infinite number of universes. Vilenkin does an impressive job of presenting the background information necessary for lay readers to understand the ideas behind the big bang and related phenomena. Having set the stage, the author then delves into cutting-edge ideas, many of his own devising. He argues persuasively that, thanks to repulsive gravity, the universe is likely to expand forever. He goes on to posit that our universe is but one of an infinite series, many of them populated by our 'clones.' Vilenkin is well aware of the implications of this assertion: 'countless identical civilizations [to ours] are scattered in the infinite expanse of the cosmos. With humankind reduced to absolute cosmic insignificance, our descent from the center of the world is now complete.' Drawing on the work of Stephen Hawking and recent advances in string theory, Vilenkin gives us a great deal to ponder."—Publishers Weekly

Reviews from Goodreads



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Many Worlds in One
1What Banged, How It Banged, and What Caused It to BangIn the context of inflationary cosmology, it is fair to say that the universe is the ultimate free lunch.--ALAN GUTH 
On a Wednesday afternoon, in the winter of 1980, I was sitting in a fully packed Harvard auditorium, listening to the most fascinating talk I had heard in many years. The speaker was Alan Guth, a young physicist from Stanford, and the topic was a new theory for the origin of the universe. I had not met Guth before, but I had heard of his spectacular
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  • Alex Vilenkin

  • Alex Vilenkin is a professor of physics at Tufts University, where he also serves as director of the Tufts Institute of Cosmology. The author of more than 150 research papers in cosmology, he has introduced a number of novel ideas to the field.