Geocentric model Geocentric model In astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a superseded description of the Universe with Earth at the center. Under the geocentric model, the Sun, Moon, stars, and planets all orbited Earth. The geocentric model served as the predominant description of the cosmos in many ancient civilizations, such as those of Aristotle and Ptolemy. Two observations supported the idea that Earth was the center of the Universe. First, from anywhere on Earth, the Sun appears to revolve around Earth once per day. While the Moon and the planets have their own motions,
Amherst Central Business District Amherst Central Business District The Amherst Central Business District is a historic district encompassing the heart of downtown Amherst, Massachusetts. Centered on the northern section of the long town common, the area has been the civic and commercial heart of the town since the 18th century. The district was listed on the National Register of Historic Places in 1991, and slightly enlarged in 2011. Amherst was originally part of Hadley, settled in 1661, and was itself known to have colonial settlements by 1728. It was incorporated in 1768. Its earliest focal point of settlement was in what is now its