A-Grav refers to anti-gravity
R-Grav refers to repulse-gravity
It is worth starting off by saying that not many humans know how these technologies work at their most fundamental level of operation. Their operational parameters and effects are generally known, however their material and power specifics are not. They are shrouded in secrecy by those companies with the TechnosphereAll the Habitats contained within the system of 'Governance Of Technology' laws. who build them and kept as trade-secrets known too very, very few people.
At the same time their distribution throughout the TechnosphereAll the Habitats contained within the system of 'Governance Of Technology' laws. is widespread, the Agency having classified many of their off-shoot products as being relatively low-TQ, and at the same time A-Grav and R-Grav products may sit side-by-side in the same virtual store under the same label, that most common one being the catch-all phrase of “Anti-Gravity”.
It is worth noting that most people really don’t give a damn about the distinction between the two gravity systems, and if you are one of those, then reading any further is a waste of your time.
R-Grav was originally intended to be called “Repulsor-lift” however it transpired that some ancient, but still extant, corporation owned the copyright to that term and refused to sell; the result being the usage of “R-Grav” instead. However, many people continue to use “Repulsor” or “Repulsorlift” when describing this technology.
R-Grav is a limited field-generation technology that directly interacts with local gravitational fields to produce a result that ‘pushes’ away from the ground.
The effect is materials-dependent i.e. It can only be produced within/by specific materials and it is also a relatively weak field with limited capabilities.
The field generated “pushes” back at the local gravitational field as a polar opposite, so a 1G field can be repulsed to a maximum negative 1G, depending on a number of factors:
1) Material: the R-Grav field is stronger in certain materials than others, how and why this is so is a trade-secret but R-Grav materials have been successfully woven into cloth, plastics and metals.
2) Initialisation: R-Grav fields require a very small amount of power to generate their full field effects. This field decreases after the power is removed returning eventually to a neutral state with no gravity-repulsive factor at all. With power supplied the material generates a constant repulsive field.
3) Power: There is a tipping-point with R-Grav materials whereby adding more power generates no further lift. This means that the body to be lifted can only then be affected by applying more R-Grav material too it, rather than by putting more power into the system itself.
4) Material Type: Different materials produce different levels of repulsive effect, and that is also affected by their physical construction; altering the base material can alter its effectiveness.
5) Distance from and Strength of local Gravity: R-Grav is completely dependent on the strength of the local gravitational field.
A 1G capable R-Grav material can only produce a negative 1G field repulsion in a 1G (or higher) gravity field. In addition there is a rapid decrease in efficiency over very minor distances, so R-Grav is usually only capable of lifting a body a short distance.
The ability to lift an object is limited and the effect of the best materials is to generate a body-lift of, at most, 1 or 2 meters on a 1G body.
R-Grav materials have been used in a very wide range of products from clothing to automobiles. Clothing is typically worn to reduce the effective weight of the person wearing it (although it obviously doesn’t change the mass) and R-Grav is used in all manner of vehicles to, again, reduce ‘effective weight’ and in some cases to produce lift to the entire vehicle.
Generally this is impractical in real-terms as either a very large area of material is required to lift something as heavy as a vehicle or the most effective, and most expensive materials have to be used.
In practice actual bodily lift is not often the intended usage, instead the purposeful use of R-Grav is “lighten the load” reducing strain on vehicle systems. Because the power requirement is so low even limited “weight reduction” can have very positive long-term effects on vehicular performance.
R-Grav fields are used extensively by many military forces, and in the construction industry, for reducing the surface-weight of machines and materials thereby allowing them to be moved “easier” and by reducing the material wear on components: a 120-ton battle-tank can have a proportion of its “weight” reduced, thereby requiring a smaller power-plant and lighter track/wheels/locomotive parts, as well as reducing wear on those same parts. It is also used to allow vehicle to more easily navigate soft-surfaces such as swamp, water and silts, allowing wheeled or tracked vehicles to more easily cope with hose surfaces.
The single most common usage of R-Grav materials is to reduce the weight of carried-items, particularly in circumstances where extended periods of time carrying heavy loads occurs – such as Infantry soldiers on exercise carrying large packs. R-Grav weaves into all military materials produces a small but significant reduction in stress on the infantry soldier and can be sustained with nothing more than a small button-cell. In such circumstances the small reduction in overall weight is significant in extended operational circumstances.
With regards to R-Grav as a material for generating body lift though; the lack of “lift” beyond a certain distance (centimetres), renders R-Grav as being largely unable to operate as a true body-lift system as it is unable to produce a strong-enough field to allow it to be used as a means of propulsion beyond “gravity-surfing” at an extremely slow rate.
The massive surface area required to generate lift on heavy bodies renders it completely useless as a “lift device”.
A-Grav refers to Anti-Gravity: the ability to generate an active gravitational field which can push against another gravitational field or a system that generates its own gravitational fields within a defined area for purposes other than movement.
A-Grav is the more typical example of what sci-fi authors of the preceding centuries considered as “anti-gravity”, able to propel as well as lift and able to generate localised gravitational fields and/or to interfere with local gravitational fields. A-Grav technology is extremely sensitive and highly restricted, available to only the highest TQ level Habitats within the ‘sphere. A-Grav is a power-intensive force requiring the constant application of power to produce a field that can be controlled in both degree and direction. It pushes back against a gravitational field – the “Push” being directly linked to the power put into the system. As such the distance a body can be lifted away from a gravitational field is linked directly to the power applied, and not the material used or the area it is applied over.
A-Grav can generate its field from a “spot” within the system and is not produced by a given area of material (although it can be). It is also directional so that “gravity-surfing” is made both possible and practical.
It is still dependent on a local gravitational field for propulsion; the stronger that fields the better the object can be lifted or propelled so long as enough power is present.
What this translates to is that the best speed and lift can be obtained the higher the local gravitational field, albeit at exponentially higher power requirements. This then forms the major draw-back to A-Grav; in that an extremely powerful source of energy is required to effectively operate such systems; however the benefit is the ability to “fly” by using A-Grav as both a means of lift as well as propulsion.
In practice A-Grav is used most often purely as a means of lift, and other systems are used for propulsion. Jet-power is common amongst flyers, ion-engines in space vehicles. Commercial civilian vehicles, particularly slower moving mass-transport vehicles, utilise A-Grav for both lift and propulsion, the slow acceleration of “gravity surfing” not being such an issue for what are, generally, slower-moving vehicles that do not require rapid acceleration. Fine control of power input is what controls the height a vehicle operates in the local field and there is no theoretical limit on “height” away from a gravity source other than the power available to the system. Practical limits do exist however, which result in the most common usage being a lift of a few thousands of meters.
However, it is worth noting that like R-Grav, A-Grav is rarely used on its own, rather in conjunction with other systems: many aircraft are fitted with A-Grav system to help them with lift at lower speeds, allowing them hover without the involvement of complex engine systems with directional thrusters. Almost all high-atmosphere “hoppers” utilize A-Grav as do most atmospheric-lift vehicles.
Military applications vary from uses similar to R-Grav up to stealthy aircraft where the use of A-Grav allows a vehicle to move without any external sound or heat being generated other than that of passage through the air; there is no exhaust so if the power-source is also stealthy you can create a very, very quiet craft, albeit one that is slow to accelerate or decelerate.
One of the most exciting uses of A-Grav though is in the generation of localised gravitational fields. This is resulting in a number of very exciting uses from gravity on/within space stations, ships and other orbitals, to its use as “inertial compensators” (a phrase much hated by scientists and Minds alike as it in no way really explains what is actually taking place, but much beloved by the general population in that it is such an old sci-fi concept that it is almost universally known and “understood” under that misleading name!).
Use within military fast-movers is also becoming widespread as the power-plants required to produce the necessary power are being steadily reduced in size and increased in their power-output capabilities. Anything that can reduce the “G-force” upon biological and mechanical systems is of obvious potential benefit to military (and civilian) systems.
The other obvious use is as Grav-Plates which produce small localised grav-fields in order to simulate partial gravity in space stations and ships or, conversely, to help counter high-gravitational natural fields on high-G planets.
The ultimate limitation upon use though is neither the system itself nor the power-plant but the control intelligence: the required computational power to continually adjust such systems is immense, as well as being needing to be error-free: any loss of A-grav during high-G manoeuvres or rapid acceleration results in seriously detrimental side-effects on both biological and mechanical systems. Such accidents have happened and have led to the introduction to the language of the term “Grav-Paste”.
As such control “mechanisms” with A-Grav need to be in the realm of AI or MI capabilities. Sub-Minds have been dedicated to operating such systems for GOTA, but use below that level, without access to Sub-Minds or AIs, is simply too dangerous to be practical.
This hasn’t stopped experimentation in such control systems, but the results of such experimentation invariably end up with the destruction of prototypes when a mistake, or slow-process, occurs resulting in the massive sheer-forces that occur when “inertial compensation” fails and “true” gravitational forces immediately reassert themselves.
However, even this is now being seen as a potential application through the development of gravitational weapons that fluctuate gravity in a localised area resulting in serious stress due to the variation of gravitational forces. Focused into a specified area, or point, and rapidly fluctuated then gravity can become a devastating weapon: the power requirements are currently extreme and the operational distance of such weapons very short, it will be some time before effective gravity weapons will become of much use.