Electricity and Magnetism, Edward M. Purcell and David J. Morin, Cambridge U. Press, New York, 2013. $80.00 (853 pp.). ISBN 978-1-107-01402-2
The third edition of Electricity and Magnetism by Edward Mills Purcell and David Morin is a welcome update to the original (McGraw-Hill, 1963) and second-edition (McGraw-Hill, 1985) texts by Purcell. The previous editions were a product of a series known as the Berkeley Physics Course. The series was influenced by MIT’s Physical Science Study Committee, which was formed in 1956, shortly before Sputnik was sent into space. The satellite’s passages, their times published by the Boston newspapers, were watched from the rooftops at MIT. The Sputnik affair shook up the US scientific establishment and led policymakers and academics to take a new look at science education in the US.
Prior to the 1960s, students at MIT and elsewhere were brought up on MIT professor Nathaniel Frank’s terse Introduction to Electricity and Optics (McGraw-Hill, 1940). The first in the less terse and widely adopted Physics textbooks by David Halliday and Robert Resnick was published in 1960 by John Wiley and Sons. Publisher Addison-Wesley later celebrated the one-millionth sale of Francis Sears’s Electricity and Magnetism (1951) at a meeting of the American Physical Society. The APS celebration may have been the inspiration for authors to start catering to the physics textbook market. Sears was joined by Mark Zemansky and Hugh Young in University Physics (Addison-Wesley, 1975), another successful textbook that has been frequently updated. The above texts, and many others, are excellent, but I think students, who are generally financially strapped, would welcome less frequent new editions, and only when substantive revision is warranted.
In 1973 Purcell—who shared the 1952 Nobel Prize in Physics with Felix Bloch for “development of new methods for nuclear magnetic precision measurements”—came to New York University to present the endowed Stanley H. Klosk lectures. At that occasion, I asked him about the possibility of a new edition of his book. He replied that the publishers wanted a rewrite, but in the meter-kilogram-second (mks) system, which he adamantly refused to do—he was more interested in devoting his time to the magnetic properties of bird navigation systems than in converting from cgs.
Now, a half-century after the original publication of Purcell’s Electricity and Magnetism, and 16 years after his death in 1997, we have this update by Morin, associate director of undergraduate studies in Harvard University’s department of physics and author of Introduction to Classical Mechanics (Cambridge University Press, 2008). The new Electricity and Magnetism sticks closely to Purcell’s original book, but it uses mks units, and in many places it amplifies and clarifies the previous editions. For example, Purcell covered electromagnetic induction and Maxwell’s equations in a single chapter; in Morin’s update, the topics are split into two chapters and Maxwell’s equations are more extensively discussed. A particularly interesting discussion in both the early and the new text includes an expression of electric and magnetic fields purely in terms of velocity-transformed magnetic and electric fields. That unification, based on principles of special relativity and the invariance of electric charge, is of fundamental interest.
In the time between the first edition and the latest, several experiments concerning fundamental-particle properties have been conducted. They include demonstrations of the equality of proton and electron charge, experiments showing that protons and neutrons are made up of quarks, investigations of the nucleons’ internal structure, and many observations of specific particle and antiparticle properties. Although the basic physics remains largely unchanged, the Purcell and Morin book has many clarifying discussions based on those experimental results, and most chapters end with current applications and a summary. Solutions to the problems represent roughly one-quarter of the text—they are a most welcome addition, particularly for self-study. (Purcell wrote out a solution manual by hand—mainly for instructors!—to accompany his first edition.) Five of eleven appendices deal with units and corresponding formulae; one each with curvilinear coordinates, radiation by accelerated charges, superconductivity, magnetic resonance, and fundamental constants; the final appendix is a mathematical summary.
The book assumes the reader’s knowledge or concurrent study of vector calculus. The physics and problems, as in the original text, are challenging and presented in stimulating ways. I believe Morin did a careful job in taking the edges off some of the rougher passages. Some years ago, one of my daughters took an Electricity and Magnetism course at Harvard that used the second edition of Purcell’s book. The text was a challenge for her, and despite Morin’s smoothing, the book remains a challenge.
H. Henry Stroke is a professor of physics at New York University. He conducts research at CERN at the intersection of nuclear and atomic physics.
