The Foucault pendulum is a device that clearly proves the fact of the Earth's rotation around its axis. It is named after its inventor, the French scientist Jean-Leon Foucault, who first demonstrated its action in the Paris Pantheon, in 1851. At first glance, there is nothing complicated in the design of the pendulum. This is a simple ball suspended from a dome of a tall building on a long rope (67 meters during the first experiment). If you push the pendulum, then after a few minutes the ball will not move in a straight line of the amplitude of the oscillation, but “write out eights”. This movement gives the ball a rotation of our planet.
Now the original device is stored in the Paris Museum of Crafts in the Church of St. Martin in the Fields, and its copies are widely replicated and used in numerous natural history museums. For some reason, in the native open spaces, the Foucault pendulum was used as an argument in favor of the non-existence of God. However, a wider fame - literary - was destined for an innocent visual aid. For it served as the name for the famous novel.
The work of Umberto Eco, The Foucault Pendulum, is rightfully considered a model of postmodernism. The author - a very well-read and erudite person - literally falls asleep to the reader with quotes, allusions and references to other literary works, historical facts and sources. Fans of this writer are advised to read his books, having at hand a large encyclopedic dictionary. But Eco does not want to shock his knowledge and not enlighten people - his plan is more grandiose.
The plot of the book seems quite realistic: the student Kazobon writes a scientific work on the monastic order of the Knights Templar. He becomes friendly with Belbo and Dtotallevi, employees of the publishing house "Garamon". Further, the narrative slides slightly from the solid soil of reality into a foggy region of unverified hypotheses, assumptions, esoteric fantasies and myths. Both historical facts about the Knights Templars and voluminous quotes from Kabbalah, the “Chemical Wedding” of the Rosicrucians, as well as Gnostic formulas and information about the magic meaning of numbers among the Pythagoreans are strewed onto readers' heads. The protagonist of the novel “The Foucault Pendulum” thinks about the posthumous fate of the organization of the Templars, especially after a certain colonel, having appeared at the publishing house, leaves them with the “Plan of the Knights of the Order of the Temple”, which has been drawn for centuries. The fact that the next day the military disappears without a trace only strengthens Kazobon’s confidence that the document is not a fake.
Gradually, the protagonist completely lost the solid ground of truth under his feet. Pavlikians and Rosicrucians, Assassins, Jesuits, and Nestorians replace him with real people. Casabon himself becomes a "possessor", fully believing in the Plan, although his girlfriend Leah assures that the document is just the seller’s calculations from a flower shop. But it’s already late: a heated imagination tells the hero that they should look for the Tellurgic axis of the world in the Parisian church of St. Martin, where the Museum of Crafts is now located and where the Foucault pendulum sways under the dome. There, they are attacked by a crowd of other "obsessed" who want to take over the plan and open the key to absolute power - the Hermetists, Gnostics, Pythagoreans and alchemists. They kill Belbo and Leah.
What did Humberto Eco want to say in Foucault's Pendulum? That esotericism is opium for intellectuals, how religion is for people? Or, come on, just touch it, crawls out into the real world, like from a Pandora’s box? Or is it that the search for the golden key, with which you can control the whole world, turns into the fact that the seeker becomes a pawn in a game of unknown forces? The author provides the reader with the answer to this question.