According to ancient and medieval science aether (Greek aith r^[1]), also spelled ther or ether, is the material that fills the region of the universe above the terrestrial sphere.

Mythological origins

The word (aith r) 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 is related to "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

In Plato's Timaeus (St-55c) Plato described aether as "that which God used in the delineation of the universe." Aristotle (Plato's student at the Akademia) included aether in the system of the classical elements of Ionian 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, and had no contrary, or unnatural, motion.^[3] Medieval scholastic philosophers granted aether changes of density, in which the bodies of the planets were considered to be more dense 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 were some early modern aether theories, however, the early modern aether has little in common with the aether of classical elements from which the name was borrowed and the aether theories are scientifically obsolete.

See also

• Akasha
• Plane (esotericism)

References

General

• FAQ - The Ancient Elements of Nature Ancient proto-scientific conceptualisations of the domain of nature into its constituent elements: Earth, Water, Air, Fire and Aether.

Specific

ca: ter (element) de:Quintessenz (Philosophie) el: ( ) es: ter (f sica) fa: ( ) it:Etere (elemento classico) nl:Ether (klassiek element) ja: ( ) pt: ter (elemento) ru: ( ) fi:Eetteri (alkuaine) tr:Es r