Geocentric model that both Venus and Mercury went around the Sun rather than the Earth, but this is no longer accepted. Martianus Capella definitely put Mercury and Venus in orbit around the Sun. Aristarchus of Samos was the most radical. He wrote a work, which has not survived, on heliocentrism, saying that the Sun was at the center of the universe, while the Earth and other planets revolved around it. His theory was not popular, and he had one named follower, Seleucus of Seleucia. In 1543, the geocentric system met its first serious challenge with the publication of Copernicus' "De revolutionibus orbium
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