In Stephen Wilk’s How the Ray Gun got its Zap two key factors for a science book’s effectiveness go into a head-to-head battle and neither entirely wins – yet the outcome is rarely bad and sometimes downright fun. The downside comes from the way the book is put together. It is a set of essays, an after-the-writing compilation, which is an approach that never makes for as effective reading as a book that is actually written as a book. However, some of Wilk’s topics are hugely entertaining or informative, and some even achieve the pop sci nirvana of managing to be both. What we have here are optical physics essays (they are a bit too formal and stiff to call articles) on topics ranging from the earliest attempts to put together a mathematical rule behind refraction to the possible nature of tractor beams. The book is divided into three sections, history, weird science and pop culture, and it is arguable that they become more interesting as you go through them. I love history of