Geocentric model much farther away than the Sun and the planets than previously conceived, making their motion undetectable, or in reality they are not moving at all. Because the stars were actually much further away than Greek astronomers postulated (making movement extremely subtle), stellar parallax was not detected until the 19th century. Therefore, the Greeks chose the simpler of the two explanations. Another observation used in favor of the geocentric model at the time was the apparent consistency of Venus' luminosity, which implies that it is usually about the same distance from Earth, which in turn is more consistent with geocentrism than
Central place theory Central place theory Central place theory is a geographical theory that seeks to explain the number, size and location of human settlements in a residential system. The theory was created by the German geographer Walter Christaller, who asserted that settlements simply functioned as 'central places' providing services to surrounding areas. To develop the theory, Christaller made the following simplifying assumptions: All areas have: Therefore, the trade areas of these central places who provide a particular good or service must all be of equal size The theory then relied on two concepts: "threshold" and "range". The result of these consumer preferences