Computing with Quantum Cats: From Colossus to Qubits, John Gribbin, Prometheus Books, 2014. $28.95 (295 pp.). ISBN 978-1-61614-921-5 Buy at Amazon
On a list of the technological developments that made the greatest impact on human civilization in the 20th century, computers must rank near the very top. In less than a century, computers have evolved from dreams of mathematicians to devices essential in almost all aspects of our personal and professional lives. Given such progress, one cannot help but wonder how computers will continue to evolve as we move deeper into the 21st century and what further effects they will have on society.
In Computing with Quantum Cats: From Colossus to Qubits, John Gribbin traces the remarkable technological progress of computing, starting with its birth by fire in World War II and ending with a glimpse of its future as quantum computing looms on the horizon. The book spans diverse topics, including the need for code breaking that first motivated computing, the remarkable properties of quantum mechanics, and the practical concerns of how a quantum computer might be built. To discuss those topics in a coherent manner is a truly daunting challenge. Gribbin is a talented science writer with plenty of experience in communicating quantum physics to the public; see, for example, In Search of Schrödinger’s Cat: Quantum Physics and Reality (Bantam Books, 1984). In his current book, he makes another commendable effort, and with only a few small exceptions, he again succeeds.
Computing with Quantum Cats is divided into six chapters, the first five each focusing on one of five scientists who played a crucial role in the development of computing: Alan Turing, John von Neumann, Richard Feynman, John Bell, and David Deutsch. For the most part, the approach is very effective. By focusing on one protagonist per chapter, Gribbin engages readers through the human element. The book is clearly well researched, and the author details the life of each scientist in significant depth. In doing so, he also paints a convincing picture of the society at the time of each discovery. We see, for example, the urgency for Western powers to break German codes during World War II. By revealing the thoughts and aspirations that drove each scientist and the society that each lived in, Gribbin successfully gives the book broad appeal.
For the nonscientist, the book may be enjoyed as a compilation of biographies and memorable stories about the scientists involved in the computing revolution. For experts in the field, like myself, those stories will also be appealing—and some of them would even lighten the mood during undergraduate lectures. In addition, the scientific concepts are introduced clearly, albeit with not much detail; the emphasis is on why the ideas fascinated the scientists who discovered them.
The human approach, however, does exhibit at least one weakness: It requires a clear scientific protagonist. That is difficult in situations where no such character exists. Thus, the book loses some charm in its final chapter, where it surveys current methods to realize quantum computers. There exist a myriad of different approaches, with no clear winner. In addition, each of them is championed by a different research group, with its own set of scientists, so no human face can tie all the science together. Consequently, the exposition comes off as rather scattered as it jumps from approach to approach; although Gribbin did an admirable job of explaining each of them, I sometimes felt like I was reading a well-written technical review paper rather than a book meant to elicit excitement. Fortunately, my complaint applies only to the final chapter.
Overall, Computing with Quantum Cats is an excellent exposition on quantum computation and the rich tapestry of scientists and discoveries that led to its eventual discovery. Those who want more scientific detail than Gribbin provides will need to look elsewhere—for example, in Deutsch’s The Fabric of Reality (Penguin Books, 1997). But Gribbin’s text is perfect for anyone interested in the history of computing and the individual scientists that drove its evolution. Its distinctly human stories will satisfy readers interested not only in the science of quantum computation but also in the dreams, inspirations, and beliefs that shaped the science.
Mile Gu is an assistant professor in the Institute for Interdisciplinary Information Sciences at Tsinghua University in Beijing. His primary research interests lie at the interface of physics and computation.
