In Greek mythology, Aether (Aither, Ether; Ancient Greek: Αἰθήρ, "brightness") is the personification of the bright upper sky — the pure air the gods breathe, above the misty lower air. Hesiod makes him son of Erebus and Nyx and brother of Hemera (Day). Orphic cosmogony often makes Aether offspring of Chronos and brother of Chaos and Erebus, and places the cosmic egg in or from him. Unpersonified aether is simply the upper atmosphere in Homer and later physics. This entry is the primordial Bright Sky, not the chemical ether alone.
Adapted from Wikipedia, "Aether (mythology)" · CC BY-SA 4.0
I.Genealogy
Hesiod's Theogony — the standard Greek stemma — has Aether and Hemera born when Nyx mates with Erebus. Other early accounts vary: Acusilaus may give Aether, Eros, and Metis as children of Erebus and Nyx, or make Aether and Nyx parents of Eros. Fragments attributed to the Titanomachy call Uranus Aether's son and say "everything came from" Aether. A Hesiodic fragment makes Aether, by Hemera, father of a figure named Brotus.
Roman authors enlarge the role: Cicero has Aether and Dies parent Caelus (Sky) and reports theologians who make Aether father of one of three Jupiters. Hyginus lists Aether among children of Chaos and Caligo, then makes Aether and Dies parents of Terra, Caelus, and Mare, and Aether and Terra parents of many abstractions, Titans, and the Furies.
II.Element and Orphic cosmogony
Unpersonified aether is the clear upper air: Homer has Sleep climb a fir on Ida that reaches up through mist into heaven (aether). Personified Aether is central in Orphic theogonies. The Hieronyman account has serpent Time father moist Aether, limitless Chaos, and misty Erebus. The Rhapsodies begin from ageless Time, father of Aether and Chaos (Chasm); Time fashions a bright white egg from or in divine Aether, from which Phanes/Protogonus hatches — so Aether is sometimes called his father.
Orphic hymns address Aether with an offering of saffron. Philosophical and Stoic reception often identifies pervasive aether with divine fire or the substance of the heavens.
III.Iconography and later sense
On the Pergamon Altar Gigantomachy frieze, Aether fights a lion-headed Giant. He seldom receives independent cult narrative beyond cosmogony and hymn.
Later chemistry and physics reused "ether" for a hypothetical medium and for diethyl ether; those scientific senses are distinct from the mythic personification treated here.