Aether
The breath above breath.
The bright upper air the gods breathe — not sunlight, which did not yet exist, but the first clarity in the cosmos.
The Myth
The Greeks distinguished two airs. Aer was the lower atmosphere — breathable, misty, the stuff mortals move through. Aether was the pure, luminous upper air, and it was what the gods breathed. The boundary between them was effectively the boundary between the mortal and divine worlds.
Hesiod makes Aether the child of Erebus and Nyx, born alongside Hemera. The genealogy is deliberate and slightly startling: the brightest thing in the early cosmos is the offspring of darkness and night. Light is not opposed to darkness in this system; it is produced by it.
The word survived its mythology by a long way. Aristotle made aether the fifth element — the incorruptible substance of the heavens, distinct from earth, water, air and fire, and the reason celestial bodies could move eternally without decay. That idea held for nearly two thousand years. It resurfaced in 19th-century physics as the luminiferous aether, the medium light was assumed to travel through, and was only dispatched by the Michelson–Morley experiment in 1887.
Orphic cosmogony gave Aether a larger role still, making him one of the primary principles emerging from the cosmic egg rather than a third-generation descendant.
How I Tell It
There is no sun yet. That constraint produced the line I am most attached to in the whole chapter — the difference between something that shines and something that merely makes seeing possible.
From the same root, but rising upward, came Aether, bright and translucent. It was the high air, the breath above breath, the first inkling of heaven.
Aether did not shine; it radiated, its light not harsh but clarifying. It did not burn like the sun, which did not yet exist, but offered the first blush of lucidity in the cosmos. Aether was revelation.