The Aluvia
The Aluvia are the rips Alu made into the fabric of the Chaos. In the void beyond he created the Zeit, where he, Ula, the First Children and all their creations dwell. Due to Ula's motherly gaze, the Aluvia appear as radiant lines of light in the Zeit cosmos. The more distant one is from the Aluvia, the more their light is obscured by a purplish nebulous haze made of all the tiny particles floating about.
As Alu is of unparalleled might, he cast a powerful ever-binding ward onto the Aluvia which slows and disorients any motes that roam close. It is this Alu's Ward which keeps the teeming masses of the Chaos out of his plane, and all but the most powerful inhabitants of the Zeit from wandering out into the Chaos.
But there are other ways to fall out of the Zeit, as all jammers know and fear. The Zeit plane is a parallel one to the Chaos. This means that for every point in the plane, there is an equivalent point in the Chaos. And the further away one wanders from the mollifying effects of the Aluvia, the more frenetic the parallel activity happening in the Chaos is.
Out in the Yon, as these dark outer reaches are called, this manifests itself as powerful storms. The Yon Squalls can be treacherous indeed. Their powerful winds can throw about jamming ships, asteroids and other debris mercilessly. The further into the Yon one goes, the worse the squalls. Some are so powerful that they temporarily break the separation between the planes and pull ships, rocks and even much larger celestial objects into the Chaos, which usually seals their doom.
The Celestial Vine
Truly it is said that the Aluvia is the only constant in the universe that is the Zeit. All the realms created initially by Alu and then the portals to planes created by the First Children hang off it like so much fruit. When a realm is bound to the Aluvia, that realm is static, grounded, predictable. But as with fruit, realms can fall off the vine whether due to catastrophic events or long neglect. The First Children can be fickle creators. They find new toys and leave old ones to wither. When a realm loses its link with the Aluvia, it is at the mercy of the Yon Squalls, at first tugging at it gently to pull it into the Yon and then more forcefully. The process can take eons, but it is said that eventually all these fallen celestial fruits fall out of the Zeit.
The Realms
The original realms were the globes created by Alu and hung off the Aluvia by threads of magical energy, invisible without the aid of magic. It would be surprising if any of these worlds have survived intact through the eons to this day, but there are some unknown reaches in the Zeit, so it is never wise to speak in absolutes.
Countless celestial bodies of all sizes and shapes have been created and destroyed since. Some were temporary playthings, and never attached to the Aluvia. Others were tethered and tended to, at least for a time.
Other realms exist in planes created by the First Children. They are connected to the Zeit by portals which are themselves attached to the celestial vine. If these portals should wander into the Chaos, the planes would still exist, but they may find themselves with some unwelcome visitors.
Sogdiana Sector
The local stretch of the Aluvia is called Sogdiana Sector. Using the Standard Aluvial Orientation, it lies to the east of the core worlds of the Sovereignty of Ashra and to the west of the Crimson Expanse.
The territory of the Sovereignty is tightly controlled by an authoritarian and militaristic regime. Jammers are usually encouraged (read intimidated) to sell their goods to Sov merchants at low prices instead of being easily allowed to range deeper into Sov territory, or even to the other side.
The Crismson Expanse is a stretch of the Aluvia which for unknown reasons was stripped clean of all realms. It is also more reddish in colour rather than the purplish it usually is. Due to the dearth of realms along this stretch of the Aluvia, it is difficult to navigate by Jammers, who rely on regular port stops along their routes to refresh their air and supplies.
Being surrounded by a political barrier on the one side, and a physical one on the other, Sogdiana Sector is quite isolated. Other than the loose coalition known as the Crook and Flail Kingdoms, concentrated along the border with the Sovereignty, the sector consists of scattered settlements on isolated bodies usually no larger than floating rocks and a smattering of portals to unimportant planes. The only exception is the portal to the Elemental Plane of Air at Ghidda.
Enterprising jammers know of ways around these barriers, via routes which sometimes involve cutting deeper into the Yon than may be wise. These routes are usually closely guarded secrets by the companies of merchants and smugglers who ply them.