Astronomy

The study of the physical universe and the incorporeal worlds. See anatomy.
Eternia - The physical world.
Astral Plane - Where souls of the dead dwell before rejoining the physical plane, pocket dimensions within the Spirit World. The astral plane's can be seen in the physical plane (the stars in the sky). There are blue stars, yellow stars, red stars, and void planes, as well as rarer anomalies.
Spirit World - Where spirits reside, before eventually rejoining their soul in the Astral Planes, then being reincarnated into the living plane.
Atmos - The universe where the Angels are from.