Geocentric model and planets were holes in invisible wheels surrounding Earth; through the holes, humans could see concealed fire. About the same time, Pythagoras thought that the Earth was a sphere (in accordance with observations of eclipses), but not at the center; they believed that it was in motion around an unseen fire. Later these views were combined, so most educated Greeks from the 4th century BC on thought that the Earth was a sphere at the center of the universe. In the 4th century BC, two influential Greek philosophers, Plato and his student Aristotle, wrote works based on the geocentric model.
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