Fizeau–Foucault apparatus unit. At the time, Foucault was working at the Paris Observatory under Urbain le Verrier. It was le Verrier's belief, based on extensive celestial mechanics calculations, that the consensus value for the speed of light was perhaps 4% too high. Technical limitations prevented Foucault from separating mirrors R and M by more than about 20 meters. Despite this limited path length, Foucault was able to measure the displacement of the slit image (less than 1 mm) with considerable accuracy. In addition, unlike the case with Fizeau's experiment (which required gauging the rotation rate of an adjustable-speed toothed wheel), he could
Foucault's Pendulum Foucault's Pendulum Foucault's Pendulum (original title: "Il pendolo di Foucault" ) is a novel by Italian writer and philosopher Umberto Eco. It was first published in 1988, and an English translation by William Weaver appeared a year later. "Foucault's Pendulum" is divided into ten segments represented by the ten Sefiroth. The satirical novel is full of esoteric references to Kabbalah, alchemy, and conspiracy theory—so many that critic and novelist Anthony Burgess suggested that it needed an index. The pendulum of the title refers to an actual pendulum designed by French physicist Léon Foucault to demonstrate Earth's rotation, which has symbolic