Geocentric model the coordinate system in order to predict the motions of planetary bodies, though doing so may make calculations easier to perform or interpret. A geocentric coordinate system can be more convenient when dealing only with bodies mostly influenced by the gravity of the Earth (such as artificial satellites and the Moon), or when calculating what the sky will look like when viewed from Earth (as opposed to an imaginary observer looking down on the entire solar system, where a different coordinate system might be more convenient). The Ptolemaic model of the solar system held sway into the early modern age;
Central Institute for the Deaf Louis's Central West End, south of the Washington University Medical School. The westernmost building of the complex is also its oldest, dating to 1928. The institute's original 1916 building was torn down around 2000, when the modern portions of the complex were built. The 1928 building, designed by local architect William B. Ittner, was listed on the National Register of Historic Places in 2015 as a reminder of the institute's early history. Central Institute for the Deaf Central Institute for the Deaf (CID) is a school for the deaf that teaches students using listening and spoken language, also known as