Cosmology

Cosmology is the study of the cosmos—the structure, organization and composition of all that there is. What most people would call the "known universe" is labeled the Prime Material Plane. It holds the world of Toril, the moon, the sun, and extends out into space to the stars. How far out into space is a question of cosmology, and the answer may depend on what cosmological model is used to describe the Prime Material plane. But there are many other planes of existence, some very much like the Prime and some so alien that they almost defy description. Like other dimensions, these other planes may overlap, surround, or penetrate the Prime Material plane, or they may be connected by some mystic avenue, often requiring magic to explore. Together, all the various planes are usually referred to as the "multiverse" and they are the focus of cosmologists as they try to map, measure, and understand the planes and their relationship to life, to death, and to each other.