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Inertia negation is a hypothetical process causing physical objects with mass to act as if they were of lower mass or were massless. The effect is the opposite of adding ballast. No such process is known to exist in the real world: if current understanding of physics is correct, such a process would be impossible. There is currently no known material or technology that is able to eliminate or negate the effects of inertia that all objects with mass possess.
According to Newton's first law, "A body will continue in its state of rest or of uniform motion in a straight line, unless compelled to change that state by a net force." Inertia is the resistance against changes in the motion of an object. Objects within objects each possess their own inertia, and will collide with each other when the containing object is moved.
A device that would be capable of inertia negation is described as being capable of reducing the inertia of both the larger containing object, and of all contained objects within, so as to make changes in motion easier, and to reduce or prevent damage due to internal collisions. The inertia is not absorbed or redirected but simply ceases to have a physical effect.
Antimatter, while being the opposite of matter, has the same kind of inertia, with the forces oriented in the same direction, as normal matter. Thus, storing antimatter on board a vehicle made of matter would not achieve any kind of inertia negation.
Inertia negation is a commonplace technology in numerous science fiction series. It is used as an explanation as to why the crew of starships can withstand complex maneuvers or acceleration to FTL speeds.
The first Sci-fi series to explicitly mention inertial dampening technology include the Star Trek , Stargate and the Alien franchises. However, the technology is depicted implicitly in many more movies and TV shows where the crew inside a spaceship are not affected by acceleration of the ship itself.
Inertial Canceller, a power in the playstation 2 game Wild arms 4 is used by a boss named Jeremy Noin. Like indicated by the name, it allows him to cancel inertia on items held in his hands... Allowing him to use even a Gatling gun without being bothered by the enormous weight or even the recoil.
In the fictional Mass Effect universe dark energy fields are used ubiquitously to modify mass of objects, e.g. of weapon projectiles to allow use of compact mass accelerators in order to achieve higher muzzle velocity, or even negate the mass of entire spaceships in order to enable FTL travel.
Inertia negation is used to counter the effects of sudden acceleration that would impart structural stresses on star ships when suddenly accelerating to or decelerating with the impulse drive, and which would cause passengers to be thrown against walls and crushed by the inertial effects of the vehicle suddenly accelerating or slowing.
Such a device does not need to negate or alter inertia – a similar effect can be achieved by creating a gravitational field opposing the acceleration of the vessel. Such technology, while still nonexistent at the present time and considered unlikely to be achieved in the foreseeable future, is by far more realistic than manipulating inertial mass.
Countering the effect of inertial forces requires a force that compensates them. For example, a pilot of a rapidly accelerating fighter aircraft is acted upon by his seat, which compensates the inertial force, which would otherwise make him fall through the seat. However, the distribution of the compensating force throughout his body is different from that of the inertial force, and thus a deformation of his body occurs (such as swelling of the legs and insufficient blood supply to the brain).
To avoid the deformation, the distributions have to match. The gravitational field discussed above is a theoretical possibility to achieve this perfectly. For bodies with homogeneous density there is also the possibility of surrounding them with a fluid of the same density. The resulting buoyant force compensates the inertial forces. It is distributed across the body surface and transferred to its interior in such a way that no deformation stress occurs. Fighter pilots often wear a liquid-filled g-suit for this purpose. However, as the human body is not entirely homogeneous (bones are denser, air in the cavities is lighter than the rest of the body), some deformation stress remains.
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities. The orientation of an object's acceleration is given by the orientation of the net force acting on that object. The magnitude of an object's acceleration, as described by Newton's Second Law, is the combined effect of two causes:
In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity, i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newton (N). Force is represented by the symbol F.
In classical physics and special relativity, an inertial frame of reference is a frame of reference that is not undergoing acceleration. In an inertial frame of reference, a physical object with zero net force acting on it moves with a constant velocity —or, equivalently, it is a frame of reference in which Newton's first law of motion holds. An inertial frame of reference can be defined in analytical terms as a frame of reference that describes time and space homogeneously, isotropically, and in a time-independent manner. Conceptually, the physics of a system in an inertial frame have no causes external to the system. An inertial frame of reference may also be called an inertial reference frame, inertial frame, Galilean reference frame, or inertial space.
In physics, jerk or jolt is the rate at which an object's acceleration changes with respect to time. It is a vector quantity. Jerk is most commonly denoted by the symbol j and expressed in m/s3 or standard gravities per second (g0/s).
Mass is the quantity of matter in a physical body. It is also a measure of the body's inertia, the resistance to acceleration when a net force is applied. An object's mass also determines the strength of its gravitational attraction to other bodies.
In science and engineering, the weight of an object is the force acting on the object due to gravity.
Newton's laws of motion are three laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows:
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach. The hypothesis attempted to explain how rotating objects, such as gyroscopes and spinning celestial bodies, maintain a frame of reference.
Dynamics is the branch of classical mechanics that is concerned with the study of forces and their effects on motion. Isaac Newton was the first to formulate the fundamental physical laws that govern dynamics in classical non-relativistic physics, especially his second law of motion.
In theoretical physics, negative mass is a type of exotic matter whose mass is of opposite sign to the mass of normal matter, e.g. −1 kg. Such matter would violate one or more energy conditions and show some strange properties such as the oppositely oriented acceleration for negative mass. It is used in certain speculative hypothetical technologies, such as time travel to the past, construction of traversable artificial wormholes, which may also allow for time travel, Krasnikov tubes, the Alcubierre drive, and potentially other types of faster-than-light warp drives. Currently, the closest known real representative of such exotic matter is a region of negative pressure density produced by the Casimir effect.
Galilean invariance or Galilean relativity states that the laws of motion are the same in all inertial frames. Galileo Galilei first described this principle in 1632 in his Dialogue Concerning the Two Chief World Systems using the example of a ship travelling at constant velocity, without rocking, on a smooth sea; any observer below the deck would not be able to tell whether the ship was moving or stationary.
The gravitational force equivalent, or, more commonly, g-force, is a measurement of the type of force per unit mass – typically acceleration – that causes a perception of weight, with a g-force of 1 g equal to the conventional value of gravitational acceleration on Earth, g, of about 9.8 m/s2. Since g-forces indirectly produce weight, any g-force can be described as a "weight per unit mass". When the g-force is produced by the surface of one object being pushed by the surface of another object, the reaction force to this push produces an equal and opposite weight for every unit of an object's mass. The types of forces involved are transmitted through objects by interior mechanical stresses. Gravitational acceleration is the cause of an object's acceleration in relation to free fall.
In the theory of general relativity, the equivalence principle is the equivalence of gravitational and inertial mass, and Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body is the same as the pseudo-force experienced by an observer in a non-inertial (accelerated) frame of reference.
Artificial gravity is the creation of an inertial force that mimics the effects of a gravitational force, usually by rotation. Artificial gravity, or rotational gravity, is thus the appearance of a centrifugal force in a rotating frame of reference, as opposed to the force experienced in linear acceleration, which by the equivalence principle is indistinguishable from gravity. In a more general sense, "artificial gravity" may also refer to the effect of linear acceleration, e.g. by means of a rocket engine.
In theoretical physics a Coriolis field is one of the apparent gravitational fields felt by a rotating or forcibly-accelerated body, together with the centrifugal field and the Euler field.
A non-inertial reference frame is a frame of reference that undergoes acceleration with respect to an inertial frame. An accelerometer at rest in a non-inertial frame will, in general, detect a non-zero acceleration. While the laws of motion are the same in all inertial frames, in non-inertial frames, they vary from frame to frame depending on the acceleration.
Rotation around a fixed axis is a special case of rotational motion. The fixed-axis hypothesis excludes the possibility of an axis changing its orientation and cannot describe such phenomena as wobbling or precession. According to Euler's rotation theorem, simultaneous rotation along a number of stationary axes at the same time is impossible; if two rotations are forced at the same time, a new axis of rotation will appear.
In common usage, the mass of an object is often referred to as its weight, though these are in fact different concepts and quantities. In scientific contexts, mass is the amount of "matter" in an object, whereas weight is the force exerted on an object by gravity. In other words, an object with a mass of 1.0 kilogram weighs approximately 9.81 newtons on the surface of the Earth, which is its mass multiplied by the gravitational field strength. The object's weight is less on Mars, where gravity is weaker, and more on Saturn, and very small in space when far from any significant source of gravity, but it always has the same mass.
Weightlessness is the complete or near-complete absence of the sensation of weight. This is also termed zero-G, although the more correct term is "zero G-force". It occurs in the absence of any contact forces upon objects including the human body.
In Newtonian mechanics, the centrifugal force is an inertial force that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is parallel to the axis of rotation and passing through the coordinate system's origin. If the axis of rotation passes through the coordinate system's origin, the centrifugal force is directed radially outwards from that axis. The magnitude of centrifugal force F on an object of mass m at the distance r from the origin of a frame of reference rotating with angular velocity ω is: