Gravity

From Space Engineers Wiki
Revision as of 15:49, 1 November 2015 by Westeastnorth (talk | contribs) (+expanded article, still needs work [pictures and formulas].)
Jump to: navigation, search
Gravity pulls radially
In real life, gravity is an attraction that matter has to other matter based upon mass. If an object has a larger mass, it will "pull" other objects towards it. The strength of this pull is directly affected by the mass of the matter of the central object and the inverse square of the distance.

Gravity in the real world always pulls objects together, regardless of the distance. However, the strength at which gravity pulls weakens as the distance from the object increases as described with Newton's first law on Gravitation. This is not the case in space engineers' Artificial Gravity Generators and the gravity produced by them. This Gravity follows almost none of the real-life laws of physics as the force does not scale with mass nor does it increase as you approach the source (it remains the same throughout the whole field). It can even pull itself, which will be explained in depth later. (See Artificial Mass)

Gravity in Space Engineers

Linear gravity in Space Engineers

In Space Engineers, gravity is a force that pulls engineers (not currently using their jetpack) and free floating items such as ores and components, in a certain direction. If multiple sources of gravity exist, then all their vectors will be added to together to calculate a direction. This can even be used to cancel each other out or used to trap objects in a 'containment field'. It notably does not affect ships, small or large nor does it affect stations or asteroids. It can be either linear (Gravity Generator) or radial (Spherical Gravity Generator). The effects of multiple generators stack, meaning while the maximum that an individual unit can generate is -1 to 1 G several of them can be overlapped in one space to create a field of very high gravity to a virtually unlimited degree.

The linear Gravity Generator is very different compared to how Gravity in real life would actually work, it produces a uniform field of gravity of the same strength and direction throughout the entire field. It does not necessarily pull objects affected towards it or away from it. Even if the object is underneath the generator it will keep falling with equal acceleration and in the same vector or direction it would have above it, it will stop accelerating under the influence of the generator only when its out of range of its field. This is unlike how gravity works in the real world and unlike how the Spherical Gravity Generator works, which operates much closer to how Gravity would work in reality - in fact you can even place objects into orbit around a spherical gravity generator.

Asteroids are notable for their absolute static nature, they neither possess a gravitational field nor are affected by them (with exception to the ores or debris that are dislodged from them) and they are completely immobile, they cannot be moved in anyway. As are the stations that are physically attached to the asteroid. They essentially have infinite mass as their inertial is impossible to overcome, with either Thrusters or Gravity manipulation.

While it does not usually affect Ships and Stations inherently due to how Space Engineers physics work, special blocks (Artificial Mass) attached to ships can be affected and manipulated by gravity. Thereby providing torque or force to an attached ship, enabling to it 'fall' - technically only the block is falling and dragging the ship with it. Despite ships/stations having a mass, as seen on the Ship's cockpit HUD element - this is not affected by artificial gravity. This mass is also known as the inertial mass, as it only affects the inertial property of ships. That is how much force is needed to move around space, larger/heavier ships take more force to stop and get moving while lighter ships require less force to stop and get moving. Conversely, heavier ships hit far harder than lighter ships - as true in real life physics. However in Space Engineers, unlike real life inertial mass and gravitational mass are two separate things; this seen very clearly with the Artificial Mass that has a true mass of 9544kg but this value does not affect the force a gravitational field would have on it. Which is only decided by the gravitational mass of a block which for the Artificial Mass would 50,000kg therefore, a fullly powered Artificial Gravity Generator operating at 1 G (9.8 m/s2) would generate a force of: 490,000 N (as derived from Newton's second law) on the Artificial Mass. Thereby accelerating it and pulling/pushing any attached to the artifical ship accordingly or producing torque (spinning around an axis). The special artificial gravity in space engineers produced by the generators are themselves not affected by gravity (their own gravity fields or otherwise) and only have their inertial mass as decided by their mass, compared to the artificial mass's gravitational mass which is affected by fields. Due to this Space Engineers can break Newtown's Third law, as there is no equal and opposite force from the Artificial mass on the Gravity Generator (the generator itself is not being pulled or pushed).

This is exactly how Gravity Drive and Gravity-based Torpedos work, by attaching a gravity generator to an artificial mass; A ship can be propelled forward, due to the artificial mass 'falling down' toward the gravity generator and dragging the attached ship - which has the gravity generator on it with the artificial mass. The Artificial mass will never reach the end of the gravity field, since they are attached to each other and will accelerate forever; However, since there is a maximum set velocity in space engineers, it cannot accelerate past 104 m/s.

The Spherical Gravity Generator can be placed at the center of an asteroid to simulate effects similar to a planet due to its radial (spherical) pull.

Updates

As of update 01.025 there is an artificial mass (AM) block, which when powered is influenced by gravity. Each Artificial Mass block is influenced independently.

As of update 01.076 there is a new Space Ball block, which is self-powered and has variable settings which include: artificial mass, friction and restitution.

Blocks that Interact with Gravity

Gravity Generator Icon.png Gravity Generator Generates a linear uniform field of artificial gravity in a 'downward' direction, decided by the orientation of the block.
Spherical Gravity Generator Icon.png Spherical Gravity Generator Generates a spherical uniform field of artificial gravity centered on the generator itself.
Artificial Mass Icon.png Artificial Mass Provides 'mass' that can be manipulated by artificial gravity fields.
Space Ball Icon.png Space Ball Provides a lighter variable 'mass' similar to an Artificial Mass but also has various properties including bounciness and friction.

See Also