TFL/Hyperspace

Hyperspace is an additional volume that is congruent with Realspace but is generally believed to be outside the conventional universe. The discovery of hyperspace shattered 20th century understanding of special and general relativity, but physicists have mostly worked out the implications.

## Entering Hyperspace

There are volumes of Realspace, generally located around 0.5 AU away from a G-class star and roughly 0.25 AU above or below the ecliptic plane, where gravity and E-M radiation combine to form what is known as a Toshido-Kearny transition point. A Realspace object that is fully encompassed by a Necklin Field while in a T-K transition point will leave Realspace and enter hyperspace.

T-K transition points are roughly 23 light seconds across and migrate in a mostly predictable pattern based on the revolution of planets, asteroids, and comets. Star flares and the gravitational fields of nearby starships can influence the position and size of T-K transition points, and most T-K transition points shrink dramatically immediately after a vessel transitions into or out of hyperspace.

## Hyperspace Characteristics

Hyperspace is mostly congruent with Realspace, but K-T transition points that are separated by light years in Realspace have K-T transition point analogues separated by dozens of light seconds in Hyperspace. The distances between K-T point analogues are always proportional to the Realspace distances between the corresponding K-T points. It is thus a convenient shortcut for interstellar travel, though ships moving in Hyperspace are not moving faster than light. 1.5 AU in Hyperspace corresponds to 1 light year in Realspace, so Realspace distances are roughly 40,000 times as long as Hyperspace distances.

Hyperspace is a weird place. The most prominent feature is the luminous ether, a non-atomic form of matter that acts much like a fluid. The luminous ether both limits the maximum speed of Realspace vessels in Hyperspace, and rapidly disperses E-M radiation moving through it. An E-M wave in the vacuum of Realspace can easily be detectable for dozens of AU; the same wave in hyperspace is barely detectable after at 5 light seconds. The density of luminous ether varies in unpredictable ways, and E-M ranging techniques (such as RADAR or LIDAR) that work flawlessly in Realspace produce unreliable values in Hyperspace.

Hyperspace is also hostile to Realspace matter. Realspace matter in Hyperspace, outside of a Necklin field, decomposes rapidly and energetically into the luminous ether.

### Luminous Ether

Luminous ether is a form of matter not made from atoms nor quarks; it only exists in Hyperspace and cannot enter a Necklin field. In Hyperspace, it acts as a fluid cloud of gaseous particles. The density of particles varies across Hyperspace in unpredictable ways, though there are many semi-consistent areas of higher or lower density and thus pressure. This, in turn, causes Hyperspace weather, most notably currents in the luminous ether but also Hyperspace storms.

Ether currents generally flow through Hyperspace in relatively straight lines for up to a few AU at rates of 1-10 Hyperfactor (HF), though currents of 12 HF have been measured. Storms and vortexes, while much rarer and covering less distance and area, have higher speeds, up to 150 HF.

Luminous ether pushes against Necklin Fields and is energized by the contact. This energetic ether can destabilize a Necklin Field, though adding more power to the Necklin Field can stabilize it again, but that also causes the ether to become even more energized. Starships in motion, faster than 2-3 HF relative to the flow, move away from the energized ether and don't have to work about their Necklin Fields collapses. Stationary or very slow moving starships rapidly find the energy to keep their Necklin Field stable growing without bound, and the Necklin Field collapses without a few hours. Stationary bases in Hyperspace are not feasible, and even slow moving vehicles that orbit a fixed point have difficulty keeping their fields stable. Multiple starships moving together through Hyperspace need to maintain separation and not follow each other directly.

### Traversing Hyperspace

A Necklin field doesn't actually create a bubble of Realspace in Hyperspace, but that is a simple analogy that describes what actually occurs. Inside the Necklin field, Realspace physics mostly hold true. A correctly configured Necklin field can be used to suck in luminous ether, accelerate it, and expel it from the field, creating thrust that pushes the Necklin field generator forward much in the same way that an air-breathing jet engine propels itself through air. Speed in hyperspace is proportional to power of the Necklin fields and inversely proportional to the cube root of the mass moving through hyperspace and is measured in Hyperspace Factor (HF). Small vessels with large engines relative to their side zip through Hyperspace at 100+ Hyperspace Factor, compared to huge vessels with minimal Necklin Fields that travel at 10-12 HF.

Navigation in Hyperspace is difficult. There are no landmarks or sensors capable of seeing into the distance. The varying density of the luminous ether mildly impacts maximum speed, and currents can increase or decrease speed by up to 12 Hyperspace Factor. Two identical vessels leaving the same point at the same nominal speed may arrive at a distance destination at radically different times. Navigating Hyperspace has been described as sailing a wooden sailing ship under a perpetual overcast without GPS or radio beacons.

Trade Routes
K-T transition point analogues are relatively fixed in distance and direction with respect to each other. Currents in the luminous ether shift and change over time, but there are a some well-known and mostly stable currents. Trade routes occur when star system A is up current from star system B and produces things that star system B wants to buy that are worth shipping, especially if there is a star system C further down current that wants to buy things that star system B produces.

Star systems are considered "off the trade routes" if they do not import or export any goods that are worth the cost of shipping, given the distance to other stars and any currents in the luminous ether. Rare earth metals are only profitably shipped for a few light years of Realspace distance by the largest and slowest of freighers; a star system that wants to export rare earth metals a dozen light years, upstream through even a mild ether current, is effectively off the trade routes. Though even systems off the trade routes get some visitors and traders, just not as many or as frequently as the systems on the trade routes.

### Combat in Hyperspace

Star nations have attempted to fight in Hyperspace. It's not easy; ships can't enter Hyperspace at the same time and it is difficult and somewhat dangerous for a fleet to rendezvous and stay in formation. It is equally difficult to find enemy vessels. If two enemies do encounter each other, any battle is extremely risky. Damage to Necklin rods or a powerplant can cause the Necklin field to collapse, followed by the total annihilation of the vehicle. Still, some nations have Hyperspace fleets, and a few pirates prefer to operate in Hyperspace despite the risks. Usually, Hyperspace battles happen near the K-T point analogues, as those locations are the places where everyone going through Hyperspace eventually travel through. However, there have been a few instances of battle occurring deep in Hyperspace, far from the K-T point analogues.

### Hypermatter

Although most of hyperspace is filled with non-atomic luminous ether, there are small amounts of atomic hyper-matter that are roughly equivalent to conventional atomic matter - similar protons and neutrons, though formed vastly different hyper-quarks (or harks). Hypermatter is the foundation of current Realspace reaction drives, since hypermatter in Realspace energetically decomposes just as Realspace matter decomposes in Hyperspace. However, by dumping enough energy into hypermatter, it is possible to stabilize it for transfer into Realspace.

Hypermatter mining requires dedicated and expensive machinery, as well as gigantic power reactors. Any vessel with a Necklin rod can traverse Hyperspace on jets of luminous ether, but only specialty vessels can capture hypermatter for later use.

## Leaving Hyperspace

T-K transition points have analogues in Hyperspace, and carefully collapsing a Necklin field while in the T-K transition point analogue causes a vessel to return to Realspace near the T-K transition point with a velocity vector relative to the system's star. However, because of the difficulties of navigating Hyperspace and the way that the T-K points are influenced by Realspace phenomenon that can't be detected from Hyperspace, the exact entry point into Realspace is difficult to determine. As vessels usually enter and leave Hyperspace on reciprocal courses at high relative speed, collisions are extremely rare but usually devastating when they occur.

Leaving hyperspace shrinks the size of the T-K point in the same way that entering it does. Fleets of ships leaving Hyperspace are scattered in Realspace and generally separated in time - 3 large ships entering Realspace over the course of a minute is a fast transit, and they may be separated by tens of thousands of miles.