The light bulbs go on

David BODANIS opens “Electric Universe” by imagining a global blackout in which minor inconvenience gives way, in a few weeks, to food and fuel shortages and a Hobbesian struggle in which, “with a world population of six billion, few people would have a chance of surviving.” Having described the hellish withdrawal symptoms, Bodanis goes on to explain how the world developed its electrical dependency.

The author of “The Secret House” and “E=mc2,” Bodanis proceeds by theme rather than chronology: “Wires” (Victorian technology), “Waves” (electromagnetism), “Wave Machines” (radio), “A Computer Built of Rock” (silicon) and “The Brain and Beyond” (the body electric). His thematic approach results in some glitches -- telegraphs and incandescent lamps, for instance, appear before we learn about Michael Faraday’s discovery of electromagnetism, which made those devices possible -- but it does allow Bodanis to streamline his narrative and race over a lot of ground.

We start in 1820s Albany, where Joseph Henry created hulking electromagnets, then head down the Hudson River to Manhattan, where Samuel Morse built his telegraph. Up in Boston, Alexander Graham Bell invented a talking telegraph -- the telephone -- that Thomas Edison helped perfect before turning his attention to the light bulb in the 1870s.

In Part 2, we jump across the Atlantic and move back a half-century to Faraday, the first to discover that moving a copper wire relative to a magnetic field induced a current in the wire. Next up is the transatlantic telegraph cable, an epic undertaking that helped confirm theories of electromagnetic fields held by William Thomson (later Lord Kelvin). Those theories, elaborated upon by James Clerk Maxwell, set the stage for modern physics.

The German professor Heinrich Hertz, who opens Part 3, conducted experiments on electromagnetic waves that opened the door to Guglielmo Marconi’s radio. The radio, in turn, led to radar, and Bodanis describes at some length that technology’s role in the air battles of World War II. Part 4 introduces us to Alan Turing, the first great theorist of computers, who spent the war years breaking ciphers at Bletchley Park, 50 miles northwest of London. The true realization of Turing’s computer visions awaited the unlocking of the mysteries of silicon at Bell Labs in the late 1940s, which led first to transistors and eventually to computers.

Throughout this whiz-bang tour, Bodanis adopts a biographical approach, interweaving science with personal details of scientists’ lives. Such an approach can pay large dividends in more finely grained studies, revealing how the social and the personal are woven into the heart of science. But it’s a mistake in a broad-brush-stroke work such as “Electric Universe,” which examines two dozen scientists in fewer than 300 pages. There isn’t space to respect the complexity of human lives, and the biographies emerge as caricatures -- Morse is a bitter xenophobe, Edison a ruthless patent thief, Turing a lonely homosexual. The book comes alive at those moments when Bodanis leaves aside the potted biography and dives into the science.

“Think of someone drumming a fast pattern with his right hand, and a separate, slower pattern with his left hand,” Bodanis writes of duplex telegraphy, the simultaneous sending of two messages on one wire. “Each hand is sending a sequence of taps, and they overlap in time, but if you listen carefully you can distinguish the two patterns.”

Bodanis later illuminates radar by explaining how a bathroom mirror works. When light beams hit the mirror’s metal coating, he writes, “loose electrons there begin to shake” and start broadcasting signals, which “lift off in stately flight patterns beside each other, carrying a close duplicate of the original image that flew in.”

That last quotation is drawn from the end notes, where, alas, much of the book’s technical detail -- and much of its most vivid writing -- is relegated. Such stuff became back matter, we are told, “to keep the main text from being loaded with details and qualifications.” But far from weighing it down, such details would have lightened up the main text. Having science so nimbly explained is the reason we pick up books like “Electric Universe” in the first place. *