A Shortcut Through Time: The Path to the Quantum Computer

This guy not only describes quantum computing in a way that should be accessible to nearly everyone, but he does it in a highly entertaining, highly readable way. By appealing to a healthy dose of abstraction, the author is able to seamlessly touch on an amazing array of topics from computational theory to quantum mechanics to cryptography. Occasionally he sinks deeper into the quantum quagmire to examine a few quantum algorithms, but he never loses sight of his intended audience: the scientifically curious layman. This book does contain a large amount of hype, but to his credit the author includes the opinions of a few noteworthy skeptics to lace all the optimism with a sprinkle of doubt. If you are looking for a quantum appetizer, or to bring yourself up to speed on the buzz behind quantum computing, I couldn't recommend this book more highly.

This book was very useful in introducing me to the mechanics of quantum computing. Using simplified concepts and compartmentalized explanations, the book manages to explain the core concepts of quantum parallelized computing using tinkertoys, gears, and black-box algorithms.I've had some previous introduction to quantum theory, but the limited depth provided by this book is exactly what I needed to base further exploratory reading on. It's a perfect "first" stepping stone for anyone interesting in exploring the field, either at depth or at leisure.

"Those in the know tell me the next high tech revolution is quantum computing. But concepts like qubits -- bits that are both on and off -- seem too bizarre to believe. How does this weirdness make computers faster, smarter, and better? Johnson, a New York Times science writer, holds your hand and drops step by step down the rabbit hole. Four hours later, you get it. He makes you smart and quantum computing real." Kevin Kelly, Wired

Your computer will soon be out of date. You know that already, especially if you know about Moore's law, which was originated forty years ago, and says that every year and a half, the density of components on a computer chip will double. From the room-sized vacuum tube monsters down to the sprightly laptop, there has been a continued decrease in size and increase in speed. But silicon technology cannot reduce forever; it is still based on atoms, and it cannot get smaller than an atom. There is no law, however, that says we must forever be dependent on silicon, and so entirely new technologies may be developed. The technology, undeveloped but promising, which has interested physicists and computer scientists the most is quantum computing. We don't have quantum computers yet, and they aren't a sure thing, but the possibilities are tantalizing. George Johnson, a science journalist, has tried to make the new technology plain in _A Shortcut Through Time: The Path to the Quantum Computer_ (Knopf), and for those of us who aren't mathematicians, physicists, or computer scientists, he has done an admirable job at making a very strange, not-yet-practical technology understandable. Few of us need to know how silicon chips work, and fewer still will ever understand how quantum computers will work. Indeed, the quantum world is so vastly strange and counterintuitive that no one really can understand it. But Johnson's book is a good introduction to the strangeness, and a good vantage point from which to watch the upcoming revolution, if it comes.Johnson's book is about a real quantum leap. The classical physics of our silicon computers does not hold within the tiny spaces inside atoms. Single particles at that scale can _really_ be in two places at once, and similarly, a quantum bit of information (known as a qubit) can be set to 1 and 0 at the same time, known as a "superposition." Qubits could be set to perform almost instantaneous calculations of huge programs, and there is no part of physics that says such computing should be impossible. Indeed, on the smallest of scales, primitive quantum computing has already been accomplished. Qubits are temperamental, and current research has to be done at supercold temperatures without the possibility of disturbance. Still, there is enormous intellectual interest in the prospect of quantum computing. One researcher in the field said that he and his colleagues are "writing the software for a device that does not yet exist." If quantum computing works, for instance, we will have to rethink all our current encryption methods, which are based on the difficulty of factoring large numbers; quantum computers do such things with ease silicon never can. You aren't going to understand quantum computers by reading this book; Johnson knows that he is trying to describe the undescribable, and he makes it clear that he is no physicist, just someone trying to understand what all the fuss is about. His book is luci

Intelligence, good sense of humor, and a spacious mind makes this book fascinating and makes very difficult materiel available to non-scientist and scientist alike. George Johnson is a rare soul who understands the materiel well enough to riff on it, build and play with the science, and yet speak in metaphors that work for me, someone who lives thoroughly in my right brain. His personal history with the subject matter, from his early days as a curious kid on through, help us take the steps with him to understand an incredibly complex field. The writing stays transparent, not opaque, interesting all the way through the technical nuts and bolts, but the concepts are far from mechanical and have left me contemplating long after.