Equation Persuasion

Many a general reader’s mathematical journey ends on encountering the first formula. An Equation for Every Occasion: 52 Formulas and Why They Matter (Johns Hopkins) remedies that through storytelling, placing numerical and scientific concepts into familiar and fathomable context. Take a_n = a\,r^{n-1}. This is the geometric progression at the heart of classical Ponzi schemes. Author John M. Henshaw’s straightforward explanation on why this equation matters is both cogent and, after a sympathetically brief introduction, equation-free: “Each new generation of investors has to be much larger than the one before in order to make the necessary payoffs, and eventually the whole thing collapses under its own weight.” In surveying the Drake equation, Amonton’s friction law, crowd-size estimating, surface tension and other topics as grand as gravity itself, Henshaw prevents math-exploration from collapsing under its own inaccessibility.