What was the Name Of the Man and His Theory that Stated that the earth was the center of the universe?

The theory that stated the Earth was the center of the universe is known as the geocentric model, primarily attributed to the ancient Greek philosopher Claudius Ptolemy. His work, particularly the "Almagest," outlined this model, which dominated astronomical thought for centuries. Ptolemy's geocentric theory suggested that all celestial bodies, including the Sun and planets, revolved around the Earth. This view was later challenged by the heliocentric model proposed by Nicolaus Copernicus.