Chapter on the life and works of Ptolemy. Which sentence in this excerpt from Great Astronomers shows that Ptolemy's theory was flawed, but that he was still the undisputed authority on astronomy for centuries?

The Geocentric theory asserts on the idea that the Earth is the center of the Solar System. The geocentric theory first started with the Greeks, mainly the philosopher Ptolemy in his Ptolemaic system, popular model of this theory. In which Ptolemy suggested that the circular pattern of the whole system shaped and equant - a mid of an epicycle moves at a constant and similar speed. But when Copernicus’ heliocentric model of the solar system came about, this theory was abandoned. As the scientific society has proven that Copernicus theory was more precise with the use of telescopes, and etc. proved that the Sun was indeed the center of the universe. Supported by different space expeditions this model was long forgotten.