The Empyrean is that part of creation that is attributed to the world of spirits. It is matter "of a much finer sort" and can be interacted with both through technology and our organic human bodies. The temporal lobe region of the brain is largely responsible for interpreting information from this part of reality. Originally, the Empirical and Empyrean Verses existed as a seamless, united universe. Under these conditions, the First Empire flourished until the Lightning War led to the actual sundering of these elements; they are now held together only by very thin and fine threads, and even these are assaulted by those manifestations of sentient humanity that choose to complete the destruction of reality. They do not know the most fundamental and basic principle underlying real existence: that life flows from the Empyrean to the Empirical. Without it, only death exists, and no life. But certainly life can continue without death.
Nature[]
In the partially-broken biverse then that is Solverse, the Empyrean Verse is the exclusive domain of the Celestials, the infinitely ancient and infinitely evolving primordial expression of sentient conscious life; that is to say, humanity. Humans bound by MEST (Matter Energy Space & Time) in some way cannot travel through the Empyrean. Celestial or ascended beings can freely access the Empyrean Verse to varying degrees, but the Empyrean interacts with the Empirical in direct ways.
Etymology[]
Spacers in the First Trilogy call it the Unseen Verse in the context of Architecture and Faith. The term Empyrean was coined very early in Second Dominion history when Joshua and his ascended companions encountered Phaeronica, leading to the Phaeron phenomenon.
Metaphysics[]
The Empyrean is separated from the Empirical by the light-boundary; that is, the average observed velocity of light. While in the Empirical Verse the speed of light acts as a ceiling that cannot be broken, the light-boundary serves as the floor of the Empyrean. Thus, the Empyrean equivalent of MEST is constantly traveling faster than visible Empirical light.
The abilities of single human beings at various times in the history of Solverse as recorded by the Infinite Empire appear at some times truly divine, miraculous, and God-like.