Physics in a Beautiful Context

Like many of the readers, my training during college and graduate school focused on experimental methods for studying cellular, molecular, and developmental systems. This training included little formal education in physics and mathematics beyond the minimal requirement, a single semester of calculus and one to two semesters of physics. If the reader is anything like me, we are now wishing that our experience included a much stronger introduction to the fundamental principles and rules of physics and mathematics, particularly as they apply to biology. Physical Biology of the Cell, written by Rob Phillips, Jane Kondev, and Julie Theriot and illustrated by Nigel Orme, bridges the fields of biology and physics. This poetically written book is one of an increasing number of texts attempting to fill the gap in resources available for understanding cellular systems from the vantage of mathematics and physics. The authors identify three audience types: the physicist curious about biology, biologists curious about physics, and those interested in learning both. However, this is not a book for novices, since it assumes that the reader has a background in at least one, if not both, of these fields. As a result, the authors reference biological structures and physical examples as if they are familiar, if not well-known, quantities. This makes Physical Biology of the Cell most clearly appropriate for use in an advanced physics course for undergraduates who have taken cell biology. The examples chosen throughout the text to describe biological phenomena or systems are drawn from physics. Without familiarity with the physics models, readers with a biology background may lack the intuitions associated with the physics references, and therefore need to learn simultaneously physics and math presented. Consequently, schools developing curricula in biophysics or mathematical biology may want to consider this book for capstone classes. The book is written as four parts: “The Facts of Life,” “Life at Rest,” “Life in Motion,” and “The Meaning of Life,” covering the essentials of cell and molecular biology; understanding mechanical equilibrium at multiple scales; modeling dynamics of motion; and bioinformatics. Each section is filled with illustrations that add significantly to our ability to see the relationships between biology, physics and mathematics. The problem sets provided at the end of each chapter are useful for developing homework assignments. Special sections that add insights to each topic are distributed throughout the text. For example, “Estimates” helps readers brush up on estimates of biological quantities such as the amount of energy required from glucose carbon bonds to manufacture physical structures in the cell; “Experiments Behind the Facts” explains how methods such as fluorescence correlation spectroscopy and fluorescence redistribution after photobleaching are used to measure diffusive dynamics; “The Math Behind the Models” helps us understand the mathematics used to describe the physics, i.e., Taylor Series; and “Tricks Behind the Math” shares tips on simplifying mathematical descriptions through substitutions and equivalencies. These special sections are not evenly distributed throughout the four parts of the book. In fact, the number and distribution of the types of special sections seems to mirror an assumption that the readers are more comfortable with mathematical models than understanding the experiments that produce the data that are modeled. The mathematics used in Physical Biology of the Cell goes from simple algebra to linear algebra (matrices, Eigen-values) and both ordinary and partial differential equations. Although the first equation is 2 2 1 kx , which describes a simple