Timeline of astronomy Rectification of Planetary Theory", eliminated the need for an equant by introducing an extra epicycle, departing from the Ptolemaic system in a way very similar to what Copernicus later also did. Ibn al-Shatir proposed a system that was only approximately geocentric, rather than exactly so, having demonstrated trigonometrically that the Earth was not the exact center of the universe. His rectification is later used in the Copernican model. Nicolaus Copernicus publishes "De revolutionibus orbium coelestium" containing his theory that Earth travels around the Sun. However, he complicates his theory by retaining Plato's perfect circular orbits of the planets. A brilliant
The Shadow of the Sun rural villages which gave him an honest perspective on what was the current situation of the continent. The Shadow of the Sun The Shadow of the Sun (, literally "Ebony") is a travel memoir by the Polish writer and journalist Ryszard Kapuściński. It was published by Penguin Books in 2001 with the English translation by Klara Glowczewska. Kapuściński spent nearly 30 years in various African countries such as Kenya, Rwanda, Nigeria, Ethiopia and more, detailing his accounts as a white, foreign visitor, of the development of the African states. Kapuściński's experience in Africa was unique, because he had the opportunity