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 Line of the Sun or American literature, which Socolovsky states can be a "common trope for understanding U.S. multicultural writers." The Line of the Sun The Line of the Sun, also titled "La Línea del Sol" in the Spanish translation, is a 1989 novel written by Puerto Rican-American author Judith Ortiz Cofer. The novel was originally published in English and tells the story of a Puerto Rican family who emigrates to the United States. The story depicts the cultural, social, and personal struggles of the family members to maintain their native culture in Puerto Rico and their new way of life in both the