Slipstream space (Slipspace for short), is a collective term for the eleven non-visible infinitesimal dimensions used for faster-than-light travel. Making a transition from one place to another via slipspace is known as a "slip", or "jump". A device which allows a spacecraft to perform slipspace transitions is generally referred to as a slipspace drive.
Slipspace is a specific set of eleven dimensions existing in a very small bundle. While these dimensions are present in normal space, they do not have an effect on the physics of normal space. By moving matter from the three 'normal' space dimensions to slipstream space, one effectively changes the laws of physics for that piece of matter. This allows faster-than-light travel without relativistic side-effects i.e., the occupants do not "warp" time, despite their superluminal speed. To the normal eye, slipspace appears pitch black, because there is nothing in the visible spectrum to see.
Slipspace is a tangle of intertwined spatial dimensions, comparably similar to a wadded up or folded piece of paper, which lie underneath the three conventional spatial dimensions of the universe; rather like taking the classic "flat sheet" used to represent gravity and crumpling it up into a ball, thereby creating extra dimensions and shorter spaces between points. Slipspace can be thought of as the detectable universe, (which, technically, it is), but with a greater number of dimensions. Our plane of existence is thought to have four dimensions (up-down, front-back, side-to-side and time), but slipspace is an eleven-dimensional spacetime. Slipspace drives use particle accelerators to rip apart normal space-time by generating micro black holes. These holes are evaporated via Hawking radiation in nanoseconds. The real quantum mechanical "magic" of the drive lies in how it manipulates these holes in space-time, squeezing vessels weighing thousands of tons into Slipspace
Slipspace also possesses different laws of physics than our "normal" universe, although some basic ones, such as energy transfer and momentum, remain the same. Due to the different laws of physics in the slipstream, times, masses, positions or velocities in slipspace are difficult to accurately measure based on the standards of normal space. Slipspace is not completely empty; clouds of primordial atomic hydrogen are relatively frequent. Occasionally, even comets are known to somehow find their way into slipspace. Objects close to one another such as fleets often group together in mass slipspace transit and may appear to sensors as a large, singular object. An object in slipspace can pass through a mass, such as a planet, without causing a collision in normal space; such an event may often go completely unnoticed. However, there may be risks involved if a ship is still early in slipspace transit and passes through a large object, such as another ship.
Slipspace travel is dangerous due to the high level of radiation encountered during the trip, which can be extremely hazardous to the crew. This is negated by the use of Lead Foil in ships, which absorb the radiation. Fissile materials also emit radiation (specifically Čerenkov Radiation, emitted when particles travel through a medium at a faster rate than light travels in that same medium.) upon exiting Slipspace; this is not harmful to humans.
Slipspace velocities are generally dependent on the ship's momentum on transition, as the Slipspace drive itself does not generate thrust. As a result, ships that are faster in normal space, such as corvettes, usually travel faster than others in the Slipstream as well. However fast it may appear, Slipspace is by no means instantaneous; "short" jumps routinely take up to hours, and "long" jumps can last several weeks or more for the crew. Recent developments in Slipspace technology has allowed for faster speeds, but not to the level of The Ancients, who were believed to be capable of instantaneous Slipspace travel across the galaxy.
Slipspace speeds can also be enhanced via using the 'Slipspace Wake' of more technologically advanced ships, such as Etherion, to accelerate the speeds of all ships following. This is a common tactic used by the Kingdom of Edolas, in order to get to battles faster. The lightyears distance between areas often necessitates this, for a planet caught unprepared could be captured long before reinforcements can reach it.