Timeline of astronomy Rectification of Planetary Theory", eliminated the need for an equant by introducing an extra epicycle, departing from the Ptolemaic system in a way very similar to what Copernicus later also did. Ibn al-Shatir proposed a system that was only approximately geocentric, rather than exactly so, having demonstrated trigonometrically that the Earth was not the exact center of the universe. His rectification is later used in the Copernican model. Nicolaus Copernicus publishes "De revolutionibus orbium coelestium" containing his theory that Earth travels around the Sun. However, he complicates his theory by retaining Plato's perfect circular orbits of the planets. A brilliant
The Pillars of the Earth Pillars of the Earth" was performed at Østre Gasværk in Copenhagen, Denmark, under the name "Jordens Søjler". Game developer and publisher Daedalic Entertainment announced their intention to develop an adventure game based on "The Pillars of the Earth", to be released in 2017. The game was published on 16 August 2017. The Pillars of the Earth The Pillars of the Earth is a historical novel by Welsh author Ken Follett published in 1989 about the building of a cathedral in the fictional town of Kingsbridge, England. It is set in the middle of the 12th century, primarily during the Anarchy,