Layers, subspace and traveling within the Imperium

General use and description

For regular travel within Synth space, a technology close to a warp drive is used.
However, to reach some edges or go further in the galaxy within a reasonable time span, other technologies have to be used.

In our case, the so-called “layers” are that technology.
Long before the Synths were even created, the Creators discovered through a series of experiments that subspace contains a system of layers which, when stabilized, can be utilized for traveling. However, the Creators could never stabilize enough a single layer for it to be useful, due to the enormous energy requirements.

Synths, building upon that research managed to stabilize a single layer after thousands of years of research.
It is this system that allows the Synths to deploy shortly practically anywhere in the galaxy.

A layer entrance looks like a rip in space, a really bright white hole in space.
Regular use of the layer is often done from a hub, most Synth dyson spheres have one of them. The biggest of such hubs is near the sphere CORE33, one of the many spheres composing the core of Synth space.
When the need arises, a layer rip may be temporarily created using a modified Blackhole class starship.
Navigating through the layer is done through a conduit, being essentially extremely strong shields to avoid ships being torn apart by gravitational forces.

Combat layers

Of course, layers aren’t always used only for travelling and other peaceful uses.
Given its nature, using layers is extremely helpful in a combat scenario, to either deploy quickly to a location or flee.

There also has been a single documented case of a layer being weaponized to trap ennemies into the layer conduit.
According to logs, fighters managed to lure ennemy ships into the layer, closing it behind them and sabotaging the conduit. As a result, the ships disappeared due to the hostile conditions inside the layer, making it an effective, although not very practical weapon.

Layer depth

As of now, Synths are using layer number 1, our universe, the base layer being layer 0.
Other layers have been discovered with time, through 2 to 5, but require even more energy for entrances to be created, maintained and conduits created, which it out of scale even for Synths.
It is theorized that there is an infinite number of layers, the deeper, the largest distance being able to be travelled.