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 Wretched of the Earth aspects of the violence and response to violence necessary for total decolonization. He also offers cautions about several different approaches to that violence. In the essay, "On National Culture" published in "The Wretched of the Earth", Fanon sets out to define how a national culture can emerge among the formerly and, at the time of its release in 1961, still-colonized nations of Africa. Rather than depending on an orientalized, fetishized understanding of precolonial history, Fanon argues a national culture should be built on the material resistance of a people against colonial domination. Fanon narrates the essay with reference to what