Physically Incorrect

I’m going to start a tradition of book reviews with this post. I’m doing this both because I enjoy reading these books, and because I’d like to try and pay for this website’s storage by adding a referral link to Amazon (hey, I’m honest!), which means if you follow it and buy the book I’ll get a small percentage of the book’s price at no additional cost to you. Since I’d rather praise than scold, I’m going to review books which I personally like, leaving the chaff out.  As this is a blog having to do with puzzles it should come as no big surprise to you that my first book will be a physics puzzle book, titled Braintwister Physics, by Goran Grimvall, a physics professor from the Royal Institute of Technology in Stockholm:

The book is somewhat thin and is divided into six chapters, each containing about 10 problems, so it has about 60 solved problems. While this number might sound small, the book’s strength lies in the detailed solutions and discussions, often expounding on a subject far beyond the mere solution required. For example, consider problem 2 from chapter 2 (the chapter is titled “No Math Required”):

In 1895, the first large-scale hydroelectric power plant was installed at Niagara Falls, New York, and by 1900 there were ten generators, rated at 5000 horsepower each. Suppose that we let this electric energy feed a giant electric heater placed in an exit tube after the turbines. Would that energy suffice to bring the water in the exit tube to boiling, or would it increase the temperature by not more than about 1 Kelvin (2 deg. Far.)?

A sloppy writer would just do a basic computation, but Grimvall’s solution covers no less than four pages of text, during which he discusses not just the solution, but tries to estimate - along with the reader - the importance of different physical effects which might contribute to the computation, and examines the hidden assumptions as few other authors do. Almost every solution of his has a section on How Physicists Think which outlines how a physicist might approach the problem. This is quite useful for aspiring physicists, as it gives a ‘real-world’ flavor to each solution; indeed, the entire approach taken by the book is to present and tackle real-world problems, using real-world physical tools, using approximations and guesstimations intelligently whenever possible.

As for the problems’ level of difficulty, I’d say they’re targeted at undergraduates or bright highschoolers. There is almost no calculus, just algebra and an appeal to the basics of physics: mechanics, thermodynamics, a bit of electricity and magnetism and of course, common sense. References to peer-reviewed journals are given at the end.

The book’s major caveat is its size and relatively small number of problems it contains. It’s the old quantity-versus-quality debate, and Grimvall has definitely chosen the latter. His detailed solutions make it unique, which means I’m giving it a thumbs up.