Geocentric model wasn't until Kepler demonstrated a physical observation that could show that the physical sun is directly involved in determining an orbit that a new model was required. The Ptolemaic order of spheres from Earth outward is: Ptolemy did not invent or work out this order, which aligns with the ancient Seven Heavens religious cosmology common to the major Eurasian religious traditions. It also follows the decreasing orbital periods of the moon, sun, planets and stars. Muslim astronomers generally accepted the Ptolemaic system and the geocentric model, but by the 10th century texts appeared regularly whose subject matter was doubts concerning
Term (time) the four-year presidential term, there are also academic midterm exams. In economics, it is the period required for economic agents to reallocate resources, and generally reestablish equilibrium. The actual length of this period, usually numbered in years or decades, varies widely depending on circumstantial context. During the long term, all factors are variable. In finance or financial operations of borrowing and investing, what is considered "long-term" is usually above 3 years, with "medium-term" usually between 1 and 3 years and "short-term" usually under 1 year. It is also used in some countries to indicate a fixed term investment such as