![[St. Pachomius Library]](title.gif)
Æther
French QUINTESSENCE
In Greek philosophy, the hypothetical fifth
element, of which the heavens might be composed. It was supposed
to have the property of self-propulsion along a circle, thus explaining
why the
heavens keep moving around the Earth. It was also associated with the
dodecahedron
in geometry; the construction of the dodecahedron is the last problem
in Euclid's Elements.
By the Middle Ages, it had been identified with the alchemical
Philosopher's
Stone.
In more modern times, the term has lost its connotation of self-movement,
and refers only to a substance imagined as filling the vacuum of "empty"
space.
Because removing the necessity of such an "æther" was a major
achievement of special relativity, that term is now rarely used in
science,
although the concept has re-entered cosmology under a variety of other
names, including the venerable synonym "quintessence".
--- Norman Hugh Redington
Return to St Pachomius Library.