Book Review: It Must Be Beautiful: Great Equations of Modern Science, Volume 50, Number 3

It Must Be Beautiful describes eleven great equations of modern science. (It is not claimed that these are the only great equations.) To qualify as great, the equation must summarize a key principle of a domain of knowledge and have significant implications for scientific and general culture. The book is thus organized around eleven essays, each devoted to one equation. The authors of the individual essays typically state the equation (but just once, and often in an appendix), explore what it says in nontechnical terms, describe its discovery and discoverer, and explain its importance. In some cases they describe their own personal involvement. They write for the general reader; there are no technical derivations either of the equations or of their consequences. The authors are divided among science journalists, academic writers on science, and practicing scientists. The latter category includes Roger Penrose, Frank Wilczek, John Maynard Smith, Robert May, and Steven Weinberg (who contributes a brief afterword). The writing is good; this is a book you can recommend to friends who may wonder what theoretical science is about. This review will not attempt to comment on all the chapters. In particular, it will skip the Schrödinger equation, evolutionary game maps, and the balance equations for ozone concentration in the atmosphere. The remaining equations include five from physics, one from information theory, one from astronomy, and one from biology. The treatment in the review will be considerably more mathematical than that of the book. The plan is to describe each equation and then provide additional commentary, sometimes making connections that were not possible for authors writing independent chapters of a book.