Orrery on display in Kassel at the Astronomisch-Physikalisches Kabinett and in Dresden at the Mathematisch-Physikalischer Salon. In "De revolutionibus orbium coelestium", published in Nuremberg in 1543, Nicolaus Copernicus challenged the Western teaching of a geocentric universe in which the Sun revolved daily around the Earth. He observed that some Greek philosophers had proposed a heliocentric universe. This simplified the apparent epicyclic motions of the planets, making it feasible to represent the planets' paths as simple circles. This could be modelled by the use of gears. Tycho Brahe's improved instruments made precise observations of the skies (1576–1601), and from these Johannes Kepler
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