Pendulum
Amir D. Aczel's book �Pendulum� traces the history of the pendulum and its place in helping prove that the Earth rotated. The book is about twice as long as it needs to be. The second half is very repetitive and many of the tangential stories and characters, while intriguing, sometimes stray too far from the main character and topic. I also felt the book didn't go into as much detail on some of the scientific material as I would have liked. While aimed at a general audience a more through appendix could have been used to expand on the pendulum and frame of reference concepts.
Recurring themes in books I've read recently include the advantages of being multidisciplinary, the role of simplicity, and having an outside perspective. The author contends that since Foucault wasn't a traditional scientist and dabbled in multiple fields, his multidisciplinary helped him to conceptualize and realize the pendulum experiment. Other scientists of the time had theories about the concept, but none took it to the logical conclusion. This ties into the simplicity of the experiment. While constructing an apparatus to let the pendulum swing in any direction with almost no friction required trial and error along with working with metal, the concept behind the experiment can be easily explained. Simplicity allows the results to be easily verified and reproduced which is vital given that the results varied by latitude. Lastly, Foucault and his experiment were initially shunned by the elite scientists of his time because he was an outsider and the experiment was so simple. Those scientists couldn't believe that they had missed it. Thankfully for Foucault others noticed the achievement and he eventually got due recognition.
1: The experiment took place in 1851.
2: His full name was Jean Bernard Leon Foucault.
9: The results of the experiment effected society, culture, and especially religion and science.
20: Kepler's Law: planets move in ellipses.
34: Newton's giant quotes referred to: Descartes, Kepler, and Galileo.
46: Foucault was both a builder and an observer.
63: Foucault was a general scientist.
81: Meter defined as a set fraction of the distance light travels in one second.
100: While the scientists of the time had the equations, none had created such a simple experiment.
103: Foucault's sine law: T = 24/sin(l), T = time to complete a circle, l = latitude.
156: Foucault had a gift of being able to explain science in layman's terms.
206: The plane of oscillation and frame of reference are still tricky topics to explain.
223: Louis-Napoleon worked to champion Foucault's work after his death.