This is a book about mapping scientific frontiers. We hear of a body of knowledge, research fronts, and scientific frontiers. Scientific frontiers are where one would expect to find not only the cutting-edge knowledge and technology of humans, but also unsolved mysteries, controversies, battles and debates, and revolutions. For example, a bimonthly newsletter Scientific Frontiers ¹ digests scientific reports of scientific anomalies: observations and facts that do not quite fit into prevailing scientific theories. This is where the unknown manifests itself in all sorts of ways. The questions addressed in this book concern the dynamics of scientific frontiers and ways that may enable us to understand better the science in the making. In this book, we will take you through our quest to visualize the growth of scientific knowledge. This is not a technical tutorial; instead, the focus is on principles of visual thinking and the ways that may vividly reveal the dynamics of scientific frontiers.