Amir Aczel tells Foucault's story in an easy, anecdotal style, with lots of digressions to give background and flavor to the tale. Most importantly, Aczel offers context for the discovery, reminding readers that great thinkers like Aristotle and Plato had the wrong idea about planetary motion, that Copernicus was lucky to die before the Inquisition could kill him for his radical notions, and that Galileo was severely persecuted by a Church that refused to accept astronomical reality. It took the sponsorship of Napoleon III to set Foucault's brilliant plan in motion, perhaps proving that science and politics can occasionally work together for the greater good. Pendulum is a delightful read, full of tidbits about the major astronomers and mathematicians of the 18th and 19th centuries. --Therese Littleton