Pendulum clock


Pendulum clock

The book of science

Tom Sharp

Christiaan Huygens horology

Pendulum clock


The tautochrone problem


Pendulum and pendula

The area under a cycloid is exactly three times the area of the circle that is used to generate it. Galileo compared these areas by tracing the curves on sheet metal, cutting them out, and weighing them, but his result was about 3.1, so he mistakenly concluded that the ratio was irrational.

Christiaan Huygens’s father, Constantijn Huygens, was a friend of Marin Mersenne, Descartes, and Galileo. So it is interesting to inquire how many of his interests Christiaan picked up from them. Descarte invented analytic geometry; Christiaan taught analytic geometry to Leibniz. Mersenne was interested in music theory and so was Christiaan, who rediscovered 31 equal temperament. Mersenne and Galileo were interested in vibrating strings and in the cycloid, and so was Christiaan. Galileo was interested in the pendulum and using it to regulate a clock and so was Christiaan. Galileo improved the telescope and so did Christiaan. Galileo was the first to observe the rings of Saturn and Christiaan was the first to identify them as rings. Furthermore, as a student, Christiaan corresponded with Fermat, who with Pascal invented probability theory; well, Christiaan wrote the first book on probability theory. But Christiaan Huygens was also important in the development of the internal combustion engine; Denis Papin was his assistant at one time. Papin contributed to early steam engines.

See also in The book of science:

Readings on wikipedia: