Hyperspace
Hyperspace is a fictional alternate universe in which some conventional laws of physics -- especially general relativity -- do not apply. Hyperspace is used in many sci-fi universes, including Star Wars, as a way to travel faster than light.
Hyperspace in Star Wars
Starships in Star Wars use hyperdrives to enter hyperspace. The exact nature of hyperspace is largely unknown, but there are various ideas as to what it is, such as:
- Hyperspace being another dimension of space, one where the lightspeed barrier is non-existent
- A parallel universe
- Simply the way the universe is viewed when traveling faster than light
Hyperspace in Babylon 5
Starships in Babylon 5 accomplish interplanetary and interstellar journeys by traveling through hyperspace. In B5, hyperspace is essentially a separate universe that ships can enter or exit through vortexes opened by jump gates or jump engines. Hyperspace creates shortcuts between locations in real space, because the distance between equivalent points in the two universes is not the same. Hyperspace is mostly empty of matter, but it is filled with energy moving in random ways that can make navigation difficult; ships must follow routes carefully mapped and marked with beacons or risk becoming lost.
A hyperspace vortex or jump point is one-way when created; ship's cannot pass through a given vortex in both directions. A single ship can create a vortex for many others, but the ship creating the vortex must be the last one to pass through it.
Telepaths in hyperspace find that the range of their abilities is greatly extended.
Hyperspace in Stargate
Entry into hyperspace is achieved when a vessel opens a stable hyperspace window. This allows a vessel to enter subspace and achieve faster-than-light velocities relative to real space whilst traveling at sublight speeds within its own layer of subspace. In this state, they can fly from one point to another in a relatively straight line. Entering and maintaining hyperspace velocities apparently requires an enormous amount of power as the Asgard must transfer power from weapons and shields to the hyperdrive.
Hyperspace in the Foundation Series
In the Foundation, hyperspace is defined as "that unimaginable region that was neither space nor time, matter nor energy, something nor nothing, [through which] one could traverse the length of the Galaxy in the interval between two neighboring instants of time.
A bit more is elaborated in Foundation's Edge. It is said that "We pass - across a gap of hundreds of parsecs sometimes - in an instant of experienced time. We are suddenly enormously far away in a direction that is very difficult to predict" The object jumping is stated to be "reduced to incorporeal tachyons, which no one has ever seen or detected".
The travel is stated to be based on "Olanjen Hyperspatial Theory", Hyperspatially the Galaxy is a tiny object-ideally a nondimensional dot-and there are no relativistic effects at all. In fact, in the mathematical formulations of cosmology, there are two symbols for the Galaxy: Gr for the "relativistic Galaxy," where the speed of light is a maximum, and Gh for the "hyperspatial Galaxy," where speed does not really have a meaning. Hyperspatially the value of all speed is zero and objects do not move with reference to space itself, speed is infinite.
The travel through hyperspace takes a very short time. For over 20 000 years, the time of the jump was only sufficient to create a short feeling described as "insideoutness". By the time of Foundation's Edge, the jump time was reduced sufficiently for all such sensations to disappear.
Hyperspace jumps are distorted by gravity fields. Because of that, navigational charts and calculations after each jumps are necessary, which could take as much as a week. In fact, blockade and enclosure were viable strategies on interstellar scale even after the fall of the First Empire due to use of standard sets of coordinates. A jump was possible in the vicinity of a planet, although it could cause severe discomfort. A new type of ships introduced in Foundation's Edge were capable of crossing the Galaxy within an hour through multiple jumps, although jumps from or into a gravity well of a planet were normally avoided.