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 Earth Sings Mi Fa Mi press release via Absolutepunk.net: "The title, "The Earth Sings Mi Fa Mi" was taken from a book written by a late 16th century astronomical theorist by the name of Johannes Kepler ["Harmonices Mundi"] and the publication just fascinated the band. Kepler’s theory suggested that each of the 9 planets in our solar system produced tones as they orbited the sun. Throughout the orbit, Venus would stay a consistent note that was considered the 6th in relation to the rest of the planets. As Earth would shift its tonality, it would create the effect of the notes moving from the major