Astronomy Notes:
People & Accomplishments:
Plato (428/7 B.C.E. – 328/7 B.C.E.) – Greek Philosopher, a student of Socrates, and teacher of Aristotle. Taught of the “World of Forms;” the idea that the material world (the earth) is made of nothing but imperfect copies of what was imagined to be perfect. Also, the perfect World of Forms (heavens) was where ideas, thoughts, concepts, imagination, reason, etc. exists. The seven planets ((in order; Sun, Moon, Mars, Mercury, Jupiter, Venus, and Saturn) were intangible gods; therefore, they were part of the World of Forms. Plato taught that when people acted on perfect ideas (i.e., built stuff), the outcome, in the material world, must be imperfect. [Socrates taught of metaphysics, the study of what is real versus what we think is real but isn’t.]
Aristotle (384 B.C.E. – 322 B.C.E.) – Greek philosopher and mathematician and a student of Plato. Credited when the early teaching of the scientific method (questioning, predicting outcomes, classifying/ organizing data, drawing conclusions founded in logic). Aristotle taught of the Universe existing in two realms. The Terrestrial Realm consisted of all material objects. All material objects, or matter, were made of combinations of the four elements (earth, air, fire, and water). Matter was classified by common physical properties (density, hot vs. cold, wet vs. dry). Comets were thought to be atmospheric phenomena, and part of the Terrestrial Realm (changes in the tail of a comet can be observed). The Celestial Realm consisted of everything in the heavens – stars, planets, etc. – and the fifth element, the “luminiferous aether.” The fifth element, according to Aristotle, was a transparent, solid but flowing, mysterious substance responsible for holding up the objects in the Celestial Realm and keeping them rotating around a central earth.
Claudius Ptolemy (90 C.E.