Gravity Manipulation

Gravity manipulation technology has a number of applications in the 27th century. It is used to create artificial gravity and negate extreme inertia on starships, and in magnetic-accelerator rings to propel starships at superluminal speeds. The discovery of such technology was the single biggest development in astronautics since Sputnik. It opened the stars up to humanity and forever changed the destiny of mankind.

The ability to manipulate gravity through technological means was first realised in the 2130s by an international team of scientists. This was achieved through electromagnetic projectors, which could produce artificial gravity wells. These early gravity projectors were incredibly large and required tremendous energy supplies to function, and as such, were not practical for providing technological gravity on starships. However, another astronautical use for this technology was soon found. A man by the name of Treviss Zirnis conceived the idea of magnetic-accelerator gates, envisioning it as a way to shorten interplanetary voyages. The first prototype performed beyond his wildest dreams; accelerating a starship up to the speed of 3,827,230,061 miles per hour. At such a speed, one could reach Pluto from Earth within an hour. This was a truly miraculous discovery. It disproved the belief that no object can exceed the speed of light (a mere 671,000,000 miles per hour) and opened a world of possibilities.

### Attractor Beam

An attractor beam, or attractor-repulsor beam, commonly known as a tractor beam, is a gravito-electromagnetic field projector which is used to pull objects toward the source of the beam, usually a starship or space-station. Beyond their use in attracting materials towards a starship, attractor beams are of great utility in assisting docking procedures. Attractor beams can also produce reverse-gravitational fields in which case they are referred to as repulsor beams.

### Gravito-Electromagnetic Accelerator

A gravito-electromagnetic accelerator, more commonly referred to as a Zirnis catapult, is a mass-driver which uses g-forces to propel starships at superluminal speeds. Zirnis catapults allow humanity to traverse the vastness of space and are vital to interstellar commerce. Without them, it would take centuries to travel between stars. The name Zirnis catapult comes from Treviss Zirnis, a Lativian scientist who invented the device in the 2140s.

Zirnis catapults are incredibly large structures. A catapult is formed from four immense rings, 3,280.84 feet in diameter, attached via long rods which form the superstructure, which is an astonishing 9,842.52 feet long. The insides of these rings are covered with very powerful gravito-electromagnetic projectors. The whole mechanism is powered via an array of solar-panels and can be manoeuvred by thruster arrays located across the superstructure. A small control tower manned by a crew of 4 manage all operations, with an additional contingent of engineers to maintain its critical systems.

The process of accelerating a starship to superluminal speeds is very delicate; lest said vessel crash into an asteroid while barreling forth at 91 billion miles an hour. The starship must remain in communication with the control tower crew at all times and follow strict protocol. The most important step is properly orienting the catapult. The control crew must angle the device to line up with the intended star-system with accuracy up to the light-year.  Once this is accomplished, the grav-projectors are powered-on and the starship is quickly accelerated to many times the speed of light. While Zirnis gates have the potential to become weapons of mass-destruction on an unfathomable scale, the weaponization of superluminal accelerators is strictly banned by numerous interstellar treaties and by local jurisdictions.

Over the course of centuries, innovation has increased the maximum acceleration possible via a Zirnis catapult. The first prototype could only propel a ship up to speeds of  3,827,230,061 miles per hour, at which it would take 272.17 days to reach the Alpha Centauri system. Modern catapults can get a ship to Alpha Centauri in only 11.65 days, travelling at speeds of 91,853,521,464 miles per hour. Below is a chart showing the maximum acceleration of each generation of Zirnis catapult.

### Gravito-Electromagnetic Field Projector

A gravito-electromagnetic field projector, more commonly referred to as an artificial gravity-projector or grav-projector, is a device which produces an artificial gravitational field through electromagnetism. Grav-projectors are one of the most significant products of the development of gravito-electromagnetic manipulation technology.  Grav-projectors are installed in the floors of starships and space-stations to create Earth-like gravity in the void. They are much more convenient than centrifugal or linear methods of artificial gravity and have facilitated the mass-scale dissemination of humanity across the stars. Besides stellar craft, grav-projectors are also used on moon and low-g worlds to create habitats with Earth-like gravity, vital to human health.

Unlike a real gravitational field, a grav-projector only exerts gravitational force in a single direction, essentially functioning like a tractor-beam. Once grav-projectors are installed within the floor plating of a starship or space-station, it is possible to establish a clear up and down. A grav-projector could theoretically produce a gravitational field of any strength, but certain limitations exist for practical reasons.

In space, grav-projectors are generally set to exert a force of 1 g. This is the strength of gravity on the surface of Earth and is the force most comfortable and healthy for humans. Humans from other telluric worlds with slightly lower or higher gs often set their projectors to a different strength, but this is usually a minor variation. When employed on the surface of moons and low g worlds, grav-projectors are set to much lower levels. For instance, Mars has gravity at 0.379 gs, so grav-projectors used in habitats generally project a field of 0.621 gs. In so doing, this creates a total force of 1g. Exertions of force on the human body which exceed 1g are harmful to one's health, and as such regulations exist as to the maximum output of grav-projectors. The usually legal limit is 3gs, though stricter legislation limits it to 2 or even 1.5 gs.

While a grav-projector generally uses gravito-electromagnetic force to pull objects toward itself, it can also be used to push objects away, essentially creating a reverse gravitational field, more colloquially known as anti-gravity. The potential use of this technology to create hover-cars and other such devices has been of serious interest to scientists for many decades now, and the concept is perfectly feasible. The obstacle halting the wide-spread introduction of anti-gravity projections is a problem of energy. Grav-projectors are already very energy intensive devices.  On average, it takes 5,000 watts per minute to create 1g of force within a 5 foot square. For a vessel to hover a few feet off the ground on a telluric world would take a minimum of 3gs of force; about 15,000 watts per minute per 5 square feet of surface area. Until nuclear-reactor technology can be radically miniaturised or hyper-efficient batteries are developed, anti-gravity vehicles remain an impracticality.

### Inertial Negator

An inertial negator is a device which produces a gravito-electromagnetic field in order to negate the extreme g-force of starships. Similarly to a grav-projector, an inertial negator produces artificial gs in a linear path. The difference between the devices is more so in purpose than in mechanism. When a starship is travelling between two planetary bodies, it is moving at extreme subluminal speeds; often around 20,503,300 miles per hour. At those speeds, about 1,298.13 gs of force would be exerted on the human body. Such speeds are gruesomely fatal, to speak nothing of what superluminal travel would do to the human body. The purpose of inertial negators is to counteract the extreme g-forces which result from starship travel, thus ensuring the safety of the crew.

Inertial negators are exceptionally important features of any starship and must be diligently maintained. Should more than 25% of a ships’ negators fail while the vessel is moving at extreme speeds, the crew will die. Intentionally deactivating inertial negators is a particularly horrific method of sabotage and, in a few tragic examples, of suicide.

While inertial negators protect against the severe effects of g-force, they do not wholly remove the effects of inertia upon the crew of a starship. Acceleration to and deceleration from extreme speeds still causes a noticeable turbulence within a vessel and an abrupt arrest of momentum would still cause the crew to be thrown about. When escaping or reentering a planetary atmosphere, inertial negators are essentially useless and thus it is during this stage in a journey that a starship’s crew experiences the most turbulence and the intensest g-forces.

### Particle Deflector Screen Emitter

A particle deflector screen emitter, more commonly known as a PDS emitter or a debris shield, is a device which uses a gravito-electromagnetic field projector to repulse incoming space debris and micro-asteroids so as to protect a starship’s hull from damage. The grav-projectors which form the emitter array are located at the bow of the ship and project a reverse gravitational field in the form of a wide cone before the vessel. This cone repulses all manner of debris, small particles and micro-asteroids moving at extreme speeds which might puncture the hull should they make contact. PDS emitters are of particular necessity when travelling at superluminal speeds.