Aristotle's Work in Meteorology and the Cosmos

In Aristotle's work, Meteorology, he discusses his observations and ideas on the earth sciences, many of which are correct. In Meteorology, Aristotle states that meteorology is, "all the affections we may call common to air and water, and the kinds and parts of the earth and the affections of its parts." As can be seen, Aristotle's use of the term "meteorology" is used in a much broader sense than the term is used today. One of Aristotle's most notable observations from Meteorology is his description of the hydrologic cycle, "Now the sun, moving as it does, sets up processes of change and becoming and decay, and by its agency the finest and sweetest water is every day carried up and is dissolved into vapor and rises to the upper region, where it is condensed again by the cold and so returns to the earth." He starts by describing the stage of evaporation by stating that "water is every day carried up." The water is then "condensed again by the cold and so returns to the earth" in the modern stages of condensation and precipitation. Through this basic breakdown of Aristotle's work, it can be seen how well of an understanding he had of the hydrologic cycle. Also, in Meteorology, Aristotle discusses his idea of Earth's history where he believes that no part of Earth is always land or always water. He believes that over time, dry land will be covered in water, and wet land will become dry. His argument includes the fact that he believes this process occurs over an extremely long period of time. Aristotle based many of his ideas about the world on the fact that he believed there was no beginning or end. He believed that every process of change in the world was a cyclical one. Both his idea of the hydrologic cycle and his idea of the existence of wet and dry parts of the Earth are examples of this argument often seen in the works of Aristotle.

Aristotle's work and studies regarding the universe and the cosmos resulted in facts that have spanned millenniums. Aristotle created a model of the universe that placed the earth directly in the center of a giant, spherical universe. Everything that had an existence was within the giant sphere, while nothing could exist outside of this sphere. He believed that there was no such thing as time, place, or space outside of the sphere. The cosmos were divided into two separate regions, the terrestrial and the celestial. The terrestrial region served home to the four main elements in a place where change was a constant process. The four main elements were earth, water, air, and fire. The rapidly changing combinations of these four elements resulted in the multitude of bodies on Earth and in the terrestrial region. Aristotle believed that if change ever stopped occurring, then the four elements would separate themselves from each other and create four separate regions. Comets and shooting stars were also within the terrestrial region according to Aristotle because he considered them to be changeable phenomena. Whereas the terrestrial region relied on change, Aristotle's celestial region was the complete opposite. The celestial region was witness to very minimal change. The absence of change was due to a certain heavenly substance which Aristotle called "aither." His aither was an imperishable substance that never disappeared. The only change that could affect the eternal substance, aither, was a change of place. The change of place of the aither could be observed as the celestial region constantly moved in a circular manner. Aristotle claimed that the celestial region was a much nobler region than the terrestrial region based on the fact that he appreciated less change, which was a significant characteristic of the celestial region.