In the Cabala the word light is used in its higher meaning–illumination. This illumination eventually descended so low that a ephemeral particle of matter was emitted; the scientists call this the photon. Einstein predicted that light would be attracted by gravity proving the particle of light which until a 100 years ago was thought to be a wave was unaffected by gravity.
When the cabalists speak about this particle of illumination which they call Ore/Light they are speaking in the spirit world when the light of the OreAinSof/LightWithoutEnd separates from the Creator and descends into creation eventually taking on the mantle of spiritual. The physical attribution of light is an exact metaphor to the spiritual meaning of light as illumination.
Ore/Light when spelled differently, but pronounced the same means Skin. The first human being was of light, but forced from the Garden of Eden had to take on the skin of an animal to survive.