INSTANT NEW YORK TIMES BESTSELLER As you read these words, copies of you are being created.   Sean Carroll, theoretical physicist and one of this world’s most celebrated writers on science, rewrites the history of twentieth-century physics. Already hailed as a masterpiece, Something Deeply Hidden shows for the first time that facing up to the essential puzzle of quantum mechanics utterly transforms how we think about space and time. His reconciling of quantum mechanics with Einstein’s theory of relativity changes, well, everything. Most physicists haven’t even recognized the uncomfortable truth: Physics has been in crisis since 1927. Quantum mechanics has always had obvious gaps—which have come to be simply ignored. Science popularizers keep telling us how weird it is, how impossible it is to understand. Academics discourage students from working on the "dead end" of quantum foundations. Putting his professional reputation on the line with this audacious yet entirely reasonable book, Carroll says that the crisis can now come to an end. We just have to accept that there is more than one of us in the universe. There are many, many Sean Carrolls. Many of every one of us.   Copies of you are generated thousands of times per second. The Many-Worlds theory of quantum behavior says that every time there is a quantum event, a world splits off with everything in it the same, except in that other world the quantum event didn't happen. Step-by-step in Carroll's uniquely lucid way, he tackles the major objections to this otherworldly revelation until his case is inescapably established.   Rarely does a book so fully reorganize how we think about our place in the universe. We are on the threshold of a new understanding—of where we are in the cosmos, and what we are made of. Praise for Something Deeply Hidden “What makes Carroll's new project so worthwhile, though, is that while he is most certainly choosing sides in the debate, he offers us a cogent, clear, and compelling guide to the subject while letting his passion for the scientific questions shine through every page.” — NPR “Enlightening and refreshingly bold.” —Scientific American “ Something Deeply Hidden  is Carroll’s ambitious and engaging foray into what quantum mechanics really means and what it tells us about physical reality.” —Science “Carroll argues with a healthy restlessness that makes his book more interesting than so many others in the quantum physics genre.” —Forbes “If you want to know why some people take [the Everett] approach seriously and what you can do with it, then Carroll’s latest is one of the best popular books on the market.” — Physics Today “Be prepared to deal with some equations—and to have your mind blown.” — GeekWire  “By far the most articulate and cogent defense of the Many-Worlds view in book-length depth with a close connection to the latest ongoing research.” —Science News  “Solid arguments and engaging historical backdrop will captivate science-minded readers everywhere.” —Scientific Inquirer “As a smart and intensely readable undergraduate class in the history of quantum theory and the nature of quantum mechanics,  Something Deeply Hidden  could scarcely be improved.” — Steve Donoghue,  Open Letters Monthly “Readers in this universe (and others?) will relish the opportunity to explore the frontiers of science in the company of titans.” — Booklist “Fans of popular science authors such as Neil deGrasse Tyson and John Gribbin will find great joy while exploring these groundbreaking concepts.” — Library Journal “[A] challenging, provocative book . . . Moving smoothly through different topics and from objects as small as particles to those as enormous as black holes, Carroll’s exploration of quantum theory introduces readers to some of the most groundbreaking ideas in physics today.” — Publishers Weekly “A thrilling tour through what is perhaps humankind's greatest intellectual achievement — quantum mechanics. With bold clarity, Carroll deftly unmasks quantum weirdness to reveal a strange but utterly wondrous reality.” —Brian Greene , professor of physics and mathematics, director of Columbia's Center for Theoretical Physics, and author of The Elegant Universe “Sean Carroll’s immensely enjoyable Something Deeply Hidden brings readers face to face with the fundamental quantum weirdness of the universe—or should I say universes? And by the end, you may catch yourself finding quantum weirdness not all that weird.” —Jordan Ellenberg , professor of mathematics at the University of Wisconsin–Madison and author of  How Not To Be Wrong   “Sean Carroll is always lucid and funny, gratifyingly readable, while still excavating depths. He advocates an acceptance of quantum mechanics at its most minimal, its most austere—appealing to the allure of the pristine. The consequence is an annihilation of our conventional notions of reality in favor of an utterly surreal world of Many-Worlds. Sean inc