From GoldenDawnPedia

A Brief History:

    The name Shu means "he who rises up". As the god of air and a god of light, or of light personified, Shu was said to make himself manifest in the beams of the Sun by day and in the light of the Moon by night. He appears as rising up from behind the earth while supporting the sun with his hands similar to the way Atlas can be seen supporting the heavens on his shoulders. Shu is the son of Atum-Ra, the husband of the goddess Tefnut and father of Nuit and Geb. It is said that Shu was created by Ra by way of masturbation. "I had union with my hand, and I embraced my shadow as a wife. I poured seed into my own mouth and I sent forth from myself issue in the form of the gods Shu and Tefnut." Egyptian Story of Creation.

Shu is the god of the wind, the atmosphere, the space between the heavens and the earth. As Lord of the atmosphere it is his duty to separate his children. Shu can be seen supporting the sky goddess and daughter Nuit above his head while his son and earth god Geb resides below his feet. It has been said that if Shu were to ever be removed from his place, chaos would come to the universe and all life would cease.