Insulae

Insulae (singular insula), are alternative dimensions to the Waking World that exist across the Dreaming. Also called 'planes of thought', these spaces diverge from reality in geography, cosmology, and even hypnometry.

History
Insulae were not always understood as 'other dimensions'. Particularly, Circadian scholarship supposed that the Elemental Wilds were, in fact, real celestial bodies in the night sky that one physically moved themselves onto via teleportation. This belief lead to the naming of four of the six planets after the critical 'four elements' observed in Djinn and alchemy: Ignis, Lapis, Aura and Aqua.

While the existence of two other planets in the night sky did not seem to deter this theory, the names have stuck - while the theory has not.

Origin
The origins of Insulae are largely unclear. However, one popular theory supposes that all Insulae are 'dreamed up' in some way, sustained by the convictions of the most powerful minds across the Dreaming. In essence, they are dreamscapes.

The Liminary
In current scholarship, Insulae are thought to exist at various points across the Dreaming in a thought-space referred to as 'the Liminary' - the gap between the Waking World and the Deep Dreaming. This is in essence the gap between reality and dream. As such, Insulae display various properties that could be considered magical as a result of them being detached, or even distant, from standard reality. The arrangment of Insulae across the Liminary is a subject of wild speculation and debate, drawn up in various hypnographs.

Major and Minor Insulae
While there are a hypothetically unknown total number of Insulae across the Dreaming, there are seven labelled as major Insulae - those which have, or have had, the greatest impact on the Waking World. In the current model, these are the following: There was additionally an eigth Major Insula, the Astramarine - Astra's own dreamscape and an afterlife of sorts - but it is now considered destroyed, or otherwise inaccesible, following the Cascade.
 * 1) The Emerald Sea, also called the Feysea
 * 2) The Black Bog, also called the Shadowmire
 * 3) The Elemental Wilds (considered one Insulae in total, subdivded into the Wilds of Fire, Water, Earth and Air)
 * 4) The Underworld
 * 5) The Abyss
 * 6) The Overworld
 * 7) Machina

Hypnographs
A hypnograph is a diagram of Insulae, which typically includes the following elements: 1) How close or far from reality each Insulae is. 2) How different Insulae might affect one another by 'proximity'. 3) How Insulae might orbit one another by some kind of dream-gravity mechanism. The current, most widely-accepted hypnograph posits that the Emerald Sea and Shadowmire are cosmologically 'close' to the Waking World - hence why their geography largely mirrors that of reality, and why when the Cascade happened in our world, it happened in both of them, too.