Repulsorlift

Repulsorlift is a technology based on tractism, which relies on said force to push against the surface of a gravity-generating body, counteracting the force of gravity and allowing the object or vehicle generating the tractism to hover.

Repulsorlift is immensely useful in transportation, as it allows a vehicle to hover above the surface of a planet and travel freely through the air, without needing wheels or tracks to move forward. This allows for vehicles to travel very efficiently at great speed whilst creating a minimal impact on the environment. Aircraft also benefit from repulsorlift, as the technology allows them to operate without wings, and allows them to take off and land vertically without rotors or high power jet engines. Reachers are used on seafaring vessels. Tight-beam repulsorlifts are some of the most important forms of the technology, as these beams of tractism can be used to launch craft from the surface of a planet into space, without the need for a physical space-elevator or for thrust based propulsion such as rockets.

Land vehicles
Land vehicles use short range repulsorlifts that interact with the ground below them, usually a road or another flattened surface. The repulsorlifts can usually lift the vehicle up to 3 meters from the surface of the road. More high end vehicles can reach altitudes of up to 10 meters, whilst exotic and specialist vehicles can reach higher altitudes.

Depending on their shape and weight, land vehicles can sport different types of repulsorlifts. Very heavy vehicles often have repulsors which point outwards in order to distribute the vehicle's mass over as large as possible an area of land, in order to minimise pressure against any one place on the surface.

Deep reaching repulsorlifts have beams that bypass surface soil and only interact with bedrock deep below the ground. These devices are also a way of minimising environmental impact.

Aircraft
Although some land vehicles can achieve altitudes that would normally be considered "flying", true aircraft are usually defined as vehicles with repulsors that act against the air around them, as opposed to the ground below them. Aircraft usually project their tracton fields onto a large volume of air around them, continually reprojecting their fields as the air they interact with is pulled downwards. When flying at speed, most air vehicles create rotating cushions of air beneath them. Many aircraft also sport traditional wings for the sake of fuel efficiency and potential emergency breakdown of the repulsorlift mechanism.

Seafaring vessels
Repulsorlifts acting against water (hydrorepulsorlifts) can be quite efficient but require constant power output to maintain altitude (just like aerorepulsorlifts but unlike land repulsorlifts). As such, many large seafaring vessels have tight beam deep reaching repulsorlifts that interact with the ground beneath the sea bed, not the water itself, and use these for locomotion. Such vessels, termed Reachers, hover about 1 meter above the surface of the ocean and can reach great size. They have all but replaced traditional ships, since they are faster, more fuel efficient and more environmentally friendly. Reachers can theoretically reach speeds in excess of 500 km/h, but most travel at around 200 km/h.

Spacecraft
Repulsorlifts are less useful in propelling actual spacecraft as they require matter to push against, which is often absent in space. However, repulsorlifts are very useful for launching material into orbit. In this area, deep reaching tight beam repulsorlifts are used, allowing the vessel being launched to push directly against the bedrock of the planet beneath it. Using this system, immensely large spacecraft can be brought into space, spacecraft that would otherwise be almost impossible to launch using thrust based chemical- or nuclear propulsion.