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Michael Guillen’s Five Equations That Changed the World (Little, Brown, £18.99, ISBN 0 316 91087 2) is that irritating sort of history in which the facts are there, clear and competently put forward, but the emotions attributed to the people are 20th-century constructs. Who would recognise “an emotionally abused prodigy from a dysfunctional family” as Daniel Bernoulli, the discoverer of the law of hydrodynamic pressure, or find from this description “a smart-alecky high-school dropout”, Einstein? Irritation at anachronism aside, Guillen packs a lot of fact into his story of five greats. And though Newton, Faraday and Einstein are predictable choices, his arguments for the inclusion of Bernoulli and Rudolf Clausius are good. Clausius is the second law of thermodynamics, that all tends to chaos and disorder: a gloomy outlook for some. For others, such as engineers, the consequences of his equation are an inspiring target to beat.