Saturday, 4 October 2014

Magnetism: a very short introduction – Stephen J. Blundell *****

When a writer friend of mine saw I was reading an introduction to magnetism, he quipped, 'What attracted you to this book?'

Joking aside, it’s a fair question. In popular science, and physics in particular, one doesn’t tend to think of magnetism as a particularly 'sexy' subject, lacking the instant appeal of, say, unification theories, quantum physics, relativity or the study of exotic astronomical objects. Blundell proves that this perception is completely misplaced.

Not only is Blundell’s book an excellent primer on magnetism, but in many ways it’s also a model on how to write popular science, because Blundell uses one branch of science to illuminate countless others. Magnetism underlies so many phenomena in the Universe that we actually get discussions of unification, quantum mechanics, relativity and pulsars - in addition to much else, besides, like the magnetite and maghemite in the beaks of homing pigeons, for example, or how Thomas Edison lost the AC/DC war.

One of my favorite approaches to popular science is the historical one, and that’s Blundell’s strategy here, at least in the first five or six chapters (which is where it makes sense). He begins with the theories of the ancient Greeks and other early notions, then moves on to the work of William Gilbert, who was the first to emphasize an experimental approach to the study of magnetism, and to realize that the Earth itself is magnet.

Other discoveries and theoretical developments covered are those by Galvani, Volta, Oersted, Ampere, Faraday, Tesla, Maxwell, Curie, Einstein, and so on. Part of this book’s joy is that even when dealing with well-known scientists, Blundell makes the material fresh by offering plenty of quotes. Hearing these great minds speak to us directly across the ages is a powerful and succinct way of helping to illuminate their personalities, adding a human dimension to the enterprise.

In the latter chapters, as topics become more modern and specialized, Blundell covers each in its context, providing just the right amount of information that’s needed to follow along. These sections cover spin, how magnetism is the key behind storage devices like hard drives, the magnetic fields of the Earth and other stars, as well as more exotic ideas like magnetic monopoles.

From the opening page, Blundell’s style is charming. He writes accessibly, regardless of the subject matter’s difficulty. I also appreciate Blundell’s lack of patience for pseudo-science and charlatanism, of which there’s been plenty (and, unfortunately, there continues to be) in the history of magnetism. 

Another element I found appealing is Blundell’s inclusion of a broad range of cultural references not directly related to science, from Handel’s Water Music (Benjamin Franklin once heard this piece performed on tuned wine glasses, and it led him to invent a new musical instrument) to the Death Star in Star Wars (which uses a tractor beam of magnet-like properties to lure in the Millennium Falcon). Blundell is also quite witty, from jests about frogs in your iPhone (because of experiments performed by Alessandro Volta, for a time it was believed that frogs were a source of electrical power) to puns about high-temperature superconductivity being a 'hot topic' in physics.

In short, his writing is fun, compelling, delightful. He’s also clearly an expert on magnetism, and his knowledge not only on the underlying theory, but its historical development, is truly impressive. I eagerly look forward to his next book. 


Review by Alvaro Zinos-Amaro

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