Aether was a primordial deity in Greek Mythology that was the son of Erebus and Nyx. He was the brother of Hemera and possibly fathered Gaea, Thalassa, and Uranus (deities of earth, sea, and heavens). Aether was believed to be the personification of the upper air that only gods breathe and not the same air that humans would breathe. The air encircling the mortal world was called Aer, but the air in the underworld was encircled in Erebos.