The purpose of this book is to explain the concepts and meaning of quantum physics—as engagingly as possible. There are other books (excellent ones) that concentrate on some current frontier such as quantum computing or string theory. My purpose is to take a broader look at the whole quantum world.
Most of the ideas of quantum physics have been around for a long time, yet they remain challenging, for the simple reason that they are largely counter-intuitive. They violate common sense. Using analogies, and with the help of many diagrams, I have tried to make these ideas comprehensible, and even exciting.
Quantum physics governs the world of the very small. For that reason, I have used the smallest bits of matter—fundamental particles such as electrons, pions, and protons, as well as atoms and atomic nuclei—to illustrate the concepts and laws of the quantum world. This means that the reader will, along the way, learn a good deal about these tiny bits of matter, even though the emphasis is on the concepts and laws more than on the bits of matter.
Animating the book’s presentation are a dozen “big ideas”—most of them from quantum theory, some from relativity theory. These ideas dictate the flow of the book, but are not put on explicit display as chapter titles or other signposts. For example, a chapter called “Quantum Jumps” deals largely with the role of probability in quantum physics (one of the big ideas), but that idea makes its appearance elsewhere in the book as well.