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 House of the Rising Sun Like many classic folk ballads, "The House of the Rising Sun" is of uncertain authorship. Musicologists say that it is based on the tradition of broadside ballads, and thematically it has some resemblance to the 16th-century ballad "The Unfortunate Rake". According to Alan Lomax, "Rising Sun" was used as the name of a bawdy house in two traditional English songs, and it was also a name for English pubs. He further suggested that the melody might be related to a 17th-century folk song, "Lord Barnard and Little Musgrave", also known as "Matty Groves", but a survey by Bertrand Bronson showed