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 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.