According to ancient and medieval science, aether (Greek αἰθήρ aithēr[1]), also spelled æther or ether, is the material that fills the region of the Universe above the terrestrial sphere.
Mythological origins
The word αἰθήρ (aithēr) in Homeric Greek means "pure, fresh air" or "clear sky", imagined in Greek mythology to be the pure essence where the gods lived and which they breathed, analogous to the air breathed by mortals (also personified as a deity, Aether, the son of Erebus and Nyx). It corresponds to the concept of आकाश (akasha) in Hindu philosophy and is linked to Brihaspati (or the planet Jupiter) and the center direction of the compass. It is related to αἴθω "to incinerate"[2], also intransitive "to burn, to shine" (related is the name Aithiopes (Ethiopians)), meaning "people with a burnt (black) visage". See also Empyrean.
Fifth element
Plato's Timaeus posits the existence of a fifth element (corresponding to the fifth remaining Platonic solid, the dodecahedron) called quintessence, of which the cosmos and all celestial bodies are made.
Aristotle included aether in the system of the classical elements of Ionic philosophy as the "fifth element" (the quintessence), on the principle that the four terrestrial elements were subject to change and moved naturally in straight lines while no change had been observed in the celestial regions and the heavenly bodies moved in circles. In Aristotle's system aether had no qualities (was neither hot, cold, wet, or dry), was incapable of change (with the exception of change of place), and by its nature moved in circles.[3] Medieval scholastic philosophers granted aether changes of density, in which the bodies of the planets were considered to be denser than the medium which filled the rest of the universe.[4] Robert Fludd stated that the aether was of the character that it was "subtler than light". Fludd cites the 3rd century view of Plotinus, concerning the aether as penetrative and non-material.[5] See also Arche.
Legacy
While special relativity showed that Maxwell's equations do not require the aether, there are still some viable aether theories.
References
- General
- Specific
- ^ "ether". The American Heritage Dictionary of the English Language. 4th ed. Boston: Houghton Mifflin, 2006.
- ^ Pokorny, Julius (1959). Indogermanisches etymologisches Wörterbuch, s.v. ai-dh-.
- ^ G. E. R. Lloyd, Aristotle: The Growth and Structure of his Thought, Cambridge: Cambridge Univ. Pr., 1968, pp. 133-139, ISBN 0-521-09456-9.
- ^ E. Grant, Planets, Stars, & Orbs: The Medieval Cosmos, 1200-1687, Cambridge: Cambridge Univ. Pr., 1994, pp. 422-428, ISBN 0-521-56509-X.
- ^ Robert Fludd, "Mosaical Philosophy". London, Humphrey Moseley, 1659. Pg 221.
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