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 Practice and Theory of Individual Psychology The Practice and Theory of Individual Psychology The Practice and Theory of Individual Psychology is a work on psychology by Alfred Adler, first published in 1924. In his work, Adler develops his personality theory, suggesting that the situation into which a person is born, such as family size, sex of siblings, and birth order, plays an important part in personality development. Adler is among the many therapists who have noted the significance and impact of the relationship between attitudes towards oneself and others, and highlighting the relationship between regard for self and love of another. Adler claimed that the tendency