Subspace or Hyperspace

"Hi, I'm Dr. Daniel Jackson. Now, you've heard the term "hyperspace" for years in sci-fi movies and television shows, but what does it really mean?"

- Instructional video shown to new members of the Stargate program.

Subspace or Hyperspace are terms used in science fiction to describe certain forms of space that can do things impossible in regular space (see also Green Rocks).

Subspace Subspace was popularized by Star Trek and is a trope for a form of space that has different physical properties from normal space and allows the Enterprise crew (and the writers) to do all sorts of things that have some degree of "scientific" consistency but can't actually happen in the real world. For example, generating a subspace field can alter the apparent mass of an object, allowing it to be moved more easily. It's also the basis of FTL Radio, which makes communications possible in ships that are moving faster than light (since real-life radio transmissions can only travel at light speed). It was used on Star Trek: The Next Generation and Star Trek: Deep Space Nine with regularity, often just to fill the Applied Phlebotinum slot for the episode. Star Trek: Voyager took this to silly extremes-at least one episode referenced hypersubspace. Your guess as to what that means is as good as ours.

Before there was Star Trek, Golden Age science fiction would sometimes include references to "sub-etheric" communications or waves. The idea of the ether had already been disproved, but the term was useful for "waves that behave kinda like light, only different."

Not to be confused with the other subspace. Or with the other other subspace.

Hyperspace In the real world, hyperspace refers to mathematical concepts involving more than 3 spatial dimensions. Hyperspace or hyperdrive is often used to describe Faster-Than-Light Travel or another dimensions or other scifi concepts, and as such has been part of the SF lexicon at least since the pulp magazines of the 1930s. For example, in Star Wars, it is how starships achieve faster-than-light travel. Likewise, Babylon 5 uses a hyperspace, but with a far different set of rules and base technologies behind it.

If both terms are used in a story, then typically subspace will only allow data transmissions, but will carry them almost instantaneously. Hyperspace will be slower, but will at least temporarily allow matter (spaceships) to travel through it.

The name subspace seems to be taken from the subobjects of various mathematical spaces, such as vector spaces in linear algebra or metric and topological spaces in topology. The name hyperspace was originally used to refer to vector spaces with more than three dimensions. Thus the origin of the hyperspace concept is probably linked to Another Dimension.

Subtrope of Another Dimension. Hyperspace may or may not be a scary place. See also Hyperspace Index.

Anime and Manga

 * In Uchuu Senkan Yamato this is where space submarines go when they "submerge". And yes, they do have periscopes to peek back into normal space with. If Space Is an Ocean, subspace is what's under the surface.

Comic Books

 * Scott Pilgrim: Ramona Flowers uses Subspace to get around quicker for her job as a delivery girl, and owns a Subspace handbag.
 * The Authority has a ship that exists in and travels through "The Bleed"- a seemingly endless expanse of red void that lies between (and connects?) each and every dimension for DC and Image comics, and possibly even Marvel and Dark Horse Comics.
 * Most Marvel Comics teleporters use some form of subspace to accomplish their teleportation - they jaunt to subspace, move a short distance, then come back out having covered vast distances. It is also stated in the original "Official Handbook of the Marvel Universe" and its subsequent variants that most characters with some form of growth draw the extra mass from there, while those who shrink store their shed mass there (until they reach a certain size limit, when they suddenly 'slip' into a different universe).

Literature

 * David Brin's Uplift novels have five different "levels" of hyperspace, each one seemingly more bizarre than the last and host to its own strange forms of life. In the meme level of hyperspace, bizarre biological transformations and even Ret-Gone are common hazards.
 * Hyperspace comes in a variety of "bands" in Weber's Empire From the Ashes, though the only difference between them seems to be the speed limit. Ships must maintain stasis fields during travel; if the field is broached, the ship is destroyed without a trace. Ships in normal space can detect ships traveling in hyperspace but not the other way around, allowing the creation of undetectable (to their targets) mines that warp into hyperspace to disrupt the stasis fields of ships passing over them in hyperspace.
 * In David Weber's Empire From the Ashes series there is Hyperspace, which is very fast but has no ability to redirect during flight, and Enchanach drive which is much slower, but allows for complex maneuvring.
 * In the Honor Harrington series, starships can enter Hyper and travel at effective FTL speeds as distances in Hyper are shorter than in realspace. The "higher" the Hyper band, the greater the speed-multiplication. Dangers include Gravity Waves and "walls" between different levels of Hyper.
 * Neal Asher's Human Polity series has Null Space, exposure to which drives an unprotected human quite mad.
 * John Meaney's sci-fi books (such as the Nulapeiron sequence) feature Mu Space, a fractal continuum (because 4 dimensions are dull compared to an infinite number of dimensions). Once again, exposure to mu-space by normal humans tends to result in screaming insanity, though both cybernetic and genetic pilots can navigate it without problem. The former are blind, another common theme...
 * Alan Dean Foster's Humanx Commonwealth stories feature both in the form of space-plus and space-minus. Space-plus is what ships travel through while space-minus is what communications travel through. Space-minus travel is faster than space-plus travel but any objects sent by space-minus get turned into soup. Later novels reveal that the Precursors figured out how to travel through space-minus and even more exotic things.
 * In the Star Wars Expanded Universe, Subspace is sometimes used for communications and sensors, but has shorter range and is slower than Hyperwave, making this a subversion, as both Subspace and Hyperspace can be used for Sensors, Communications and Travel, but Hyperspace is unilaterally faster.
 * In the Animorphs series, "Z-space" is the place where Shapeshifter Baggage goes, and spaceships travel in it for FTL.
 * Iain M. Banks' Culture novels feature two types of Hyperspace: Ultraspace and Infraspace. This is a result of the description of the nature of the Universe in those novels - as the Universe expands, other Universes are expanding "inside" it (in a multi-dimensional analogue of a kind of expanding onion, with the individual layers of the onion representing Universes). Hyperspace is found "in between" the Universes, with Ultraspace defined as the Hyperspace between a Universe and the one "above" it and Infraspace being defined as the one between a Universe and the one "below" it. Interstingly, these spaces appear to have a plasticity—a ship that is accelerating hard is described as creating churning waves in Ultraspace.
 * John E. Stith's Redshift Rendezvous features several levels of Hyperspace in which the universe is progressively smaller and the speed of light decreases with each step. The story is largely concerned with a murder mystery on a spaceship traveling in the level where the speed of light is 10 m/s and relativistic effects are a part of everyday life.
 * In 50 Great Short Short Science Fiction Stories one of the short stories deal with breaking through to hyperspace only to discover that it is slower than light speed and thus useless.
 * All FTL travel in The History of the Galaxy is done through a dimension/anomaly called "hypersphere". Unlike the mathematical term, which simply means a sphere in more than 3 dimensions, this hypersphere is more like your typical sci-fi hyperspace. It exists alongside normal space/time and appears to have a spherical shape (with our galaxy surrounding it). Like any sphere, it has a center, and several later (timeline-wise) novels deal with what's located there and the impact it has on interstellar travel. The properties of hypersphere are stated in most novels, with novels dealing with the nature of hypersphere going into more detail. Of note is the fact that humans are one of the few known races to have developed hyperdrives (although the discovery of hypersphere itself was a complete, and tragic, accident, involving the disappearance of the first extrasolar colony ship). Most other races have learned to use the "horizontal" force-lines in hypersphere (they connect large stellar bodies such as stars or planets) as tunnels of sorts, creating a Portal Network. While they don't need ships to travel from planet to planet, they are limited to the network, until their ships traveling on sublight can set up a gate in a new system. When humanity first encounters them, the aliens quickly adapt human hyperdrives for their own ships. Hyperdrives are made up of two generators: one to "submerge" a ship into hypersphere and one to "surface" it back to normal space. They are designed to be infallible and almost never break down.
 * In James H. Schmitz's Federation of the Hub series, special agent Heslet Quillan's cover is that he's a major in the "Subspace Engineers." These stories don't seem to spell out quite what their notion of subspace does, but given that one Space Station is shown to have a fairly large subspace section -- there's a reference to starships docked in subspace locks -- it may be a kind of Pocket Dimension to increase the station's usable volume.

Live Action TV

 * In The Tomorrow People, John theorizes that their form of teleportation involves travel through hyperspace. They later learn that Tomorrow People who do not successfully "Break out" (ie. come into their powers) get lost in hyperspace and eventually lose bodily cohesion. Elizabeth is saved from such a fate in her introductory episode. John later adjusts their Jaunting belts to "change the angle" at which they enter hyperspace, as justification for a special effect change. In the Big Finish series, one of the villains is the insane, disembodied consciousness of a Tomorrow Person who had become stuck in hyperspace.
 * In Stargate SG-1, subspace and hyperspace are both used, with subspace being used for communications and hyperspace used for transportation. Travel through hyperspace is slower than communication through subspace, making this a textbook example of the trope. The only exception is when wormholes (see Stargates) are used, which are established as being a near-instantaneous means of travel.

Tabletop Games

 * The Warhammer 40,000 verse has an immaterial, psychic, parallel dimension known technically as the "Immaterium", colloquially (and classically) as the "Empyrean", also known as "Warpspace", the "Sea of Souls", and a number of other names, but most commonly called the "Warp". The Warp fits this trope as a hyperspace, filled with daemons, the occasional deity, the and is the source of all psychic and magic sorcerous power. Direct exposure to the Warp or it's gradual influence causes mutation, insanity, and a high risk of Demonic Possession, and (for humans at least) the people able to navigate it are blind to normal space.
 * Since you go to the Warp when you die, hyperspace in Warhammer 40k really is flying through Hell. Humans don't have a strong enough psyche to hold themselves together, so their souls will either just dissolve back into the Warp or "lose sense", intuitively becoming animalistic or comatose—assuming that they don't get eaten by Daemons before either of those can occur. The space elves Eldar, on the other hand, can survive and remain cognizant in the warp—and will do almost anything to avoid it.
 * That's because they accidentally created an Eldar-eating Chaos God(dess?). The Warp used to be a safe place for them, but no longer. That's why they use soulstones, is to prevent them from getting into the Warp.
 * While the Warp jump remains the primary means of FTL travel for many races, the Webway is a hyperspace utilized almost exclusively by the Eldar. It is made of a series of tunnels somewhere between the Warp and realspace, connecting portals from millions of locations in realspace together. It's limited in that the Webway portals are fixed and new locations must have a portal built at that location to be accessed afterwards, and that since the cataclysmic fall of the Eldar, many parts of the Webway have been destroyed, lost, inhabited by Daemons or other strange creatures and dangerous entities; yet despite all of this, Webway travel is much quicker and safer than relying on Warp jump technology.
 * Yet other species have different means of FTL travel: Necrons, who use unimaginably advanced technology, go through subspace by way of their use of inertialess drives to accomplish the setting's only actual FTL travel.
 * Tyranids use a subspace mean of FTL by a living creature that harnesses a neighboring planetary systems' gravity well.
 * The Tau skirt the border between hyperspace and subspace, having not mastered the technology for a full translation into the Warp, "skimming" the border between space and Warpspace instead.
 * The Tau can't really go into the Warp because they have no Psykers - they have no means to truly access it beyond "skimming" the divide between the galaxy and the Immaterium (whatever that means), and they wouldn't be able to navigate through the Warp even if they got there. And it turns out, even for the unpsychic Tau, being lost in Hell is a bad thing.

Web Comics

 * Last Res0rt calls it vectorspace, which is good both for FTL travel as well as a handy Hyperspace Arsenal.

Video Games

 * The classic computer game Elite called it Witch Space.
 * In the Halo series it's called slipspace, but works exactly like any other hyperspace concept.
 * The Homeworld video game series treats hyperspace as a sort of time-delayed quantum teleportation requiring massive amounts of energy. Sometimes it goes badly.
 * Star Control II has Hyperspace, the standard method of interstellar travel, and Quasi-Space, which after obtaining a certain item, you are able to travel through for the cost of 10 fuel. Once in Quasi-Space you can move your ship without consuming fuel and go through a portal to Hyperspace, it's the most efficient method for long trips in the game.
 * Important in The Subspace Emissary, natch.
 * The Free Space series uses a kind of hyperspace drive (called a "subspace drive") for short range jump inside a system. For long range jumps between star systems, the same drive is used with a network of stable wormholes (called "Jump Nodes"), that are otherwise completely invisible in normal space. As a result, new star systems can only be reached if a wormhole leading to it is discovered. The last level in the first game even takes place in one of these wormholes, while the sequel culminates in a desperate plan to
 * Sword of the Stars has both. Subspace, also called node space, is used by humans and the Zuul to travel between stars (humans use natural fixed tunnels, while the Zuul "dig" their own, which are unstable and collapse over time). The Tarka use hyperdrives to generate localized hyperspace bubbles around their ships to propel themseves to FTL speeds. It is possible that the Hivers' Portal Network also uses hyperspace for instant teleportation between gates. While the method used by the Morrigi is known only as either the Void Cutter Drive or the Flock Drive, it can be assumed also uses hyperspace.
 * The Hiver gates are described as sending objects and messages through the "skin" of the universe. The novel Deacon's Tale claims that it's only safe for Hivers. When Cai Rui (a human) travels through a gate, he feels like he's being turned inside out.