The Quantum Subspace Tuner

The Quantum Subspace Tuner, or QST, is an engine that enables interstellar travel of starships, and is a plot device in Singularity.

Creation
Not long after the Singularity Event, mankind and the synthetic life forms decided to tackle the overwhelming task of human overpopulation of Earth. With no other planet to immediately colonize in Earth's solar system, mankind and synthetic kind, set about to discover the means to travel to other stars to resettle human populations on distant planets.

In 2256, they produced the first crude, but functional device that allowed a space shuttle sized craft to travel to the nearest star, Proxima Centauri, in less than one Earth month. Christened the Pathfinder, the craft was the first ship in Earth's history to travel faster than the speed of light. While travel between stars was not instantaneous, it made future journeys to futher stars more viable, as the occupants inside the craft did not have to spend their entire lifespans to reach another star system.

Function
The Quantum Subspace Tuner allows a ship to travel to any point in space that vibrates on a quatum level. The QST uses a quatum computer to determine the vibration of two quantum entangled particles in space and creates a wave between them. The ship then rides this wave through subspace, a lower deminsion of three deminsional space, and arrives faster than a particle traveling at the speed of light would. Since this wave insulates the ship from the realtivelistic effects of normal space, occupants traveling in a ship traveling along this wave do not experience time dialtion. The journey is not instaneous however, as ships using the QST arrive months after leaving their initial destination.

The distance traveled by ships is proportional to the the amount of energy used to supply the QST to create the wave to be traveled upon. For example, a low powered QST can only create short wave between two planets, while a ship supplying a QST with massive amounts of energy can travel between multiple star systems. With high energy consumption as a detrimental factor to how far a ship can travel, ships that must travel constantly between star systems, such as resupply ships or warships, are tremendously large, on the order of miles long to several kilometers long, depending on the mission type or cargo carried. These ships use most of their structures to produce and store the vast amounts of energy required for such long durations in space.

Each ship using a QST has a unique identifier known as a positron spin. As a ship enters or exits subspace, positrons (or the antiparticle to regular electrons) build up on the ship's hull. These positrons are oriented (their magnetic spin) along sthe ship's hull in such a peculiar fashion that they always align in a certain way on a specific ship. This spin, or orientation, is detecable by positron sensors, allowing for quick identification in battle as positrons arrive first before a ship does in a phenomena known as positron bias. Using this method, ships can send emergency messages to ships arriving late to a battle and identify ship type and make up.