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Force Field (physics)
In physics, a force field is a vector field corresponding with a non-contact force acting on a particle at various positions in space. Specifically, a force field is a vector field \vec, where \vec(\vec) is the force that a particle would feel if it were at the point \vec. Examples *Gravity is the force of attraction between two objects. A gravitational force field models this influence that a massive body (or more generally, any quantity of energy) extends into the space around itself. In Newtonian gravity, a particle of mass ''M'' creates a gravitational field \vec=\frac\hat, where the radial unit vector \hat points away from the particle. The gravitational force experienced by a particle of light mass ''m'', close to the surface of Earth is given by \vec = m \vec, where ''g'' is the standard gravity. *An electric field \vec is a vector field. It exerts a force on a point charge ''q'' given by \vec = q\vec. Work Work is dependent on the displacement as well as the force a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Work (physics)
In physics, work is the energy transferred to or from an object via the application of force along a displacement. In its simplest form, for a constant force aligned with the direction of motion, the work equals the product of the force strength and the distance traveled. A force is said to do ''positive work'' if when applied it has a component in the direction of the displacement of the point of application. A force does ''negative work'' if it has a component opposite to the direction of the displacement at the point of application of the force. For example, when a ball is held above the ground and then dropped, the work done by the gravitational force on the ball as it falls is positive, and is equal to the weight of the ball (a force) multiplied by the distance to the ground (a displacement). If the ball is thrown upwards, the work done by its weight is negative, and is equal to the weight multiplied by the displacement in the upwards direction. When the force is const ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Force
The Force is a metaphysical and ubiquitous power in the '' Star Wars'' fictional universe. "Force-sensitive" characters use the Force throughout the franchise. Heroes like the Jedi seek to "become one with the Force", matching their personal wills with the will of the Force, while the Sith and other villains exploit the Force and try to bend it toward their destructive desires. The Force has been compared to aspects of several world religions, and the phrase "May the Force be with you" has become part of the popular-culture vernacular. Concept and development Creation for the original films George Lucas created the concept of the Force to address character and plot developments in '' Star Wars'' (1977). He also wanted to "awaken a certain kind of spirituality" in young audiences, suggesting a belief in God without endorsing any specific religion.''The Mythology of Star Wars'' (2000 documentary) He developed the Force as a nondenominational religious concept, "distill d fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stasis Field
A stasis or stasis field, in science fiction, is a confined area of space in which time has been stopped or the contents have been rendered motionless. Overview A stasis field is imagined to be a region in which a stasis process is in effect. Stasis fields in fictional settings often have several common characteristics. These include infinite or nearly infinite rigidity, making them "unbreakable objects" and a perfect or nearly-perfect reflective surface. Most science fiction plots rely on a physical device to establish this region. When the device is deactivated, the stasis field collapses, and the stasis effect ends. Time is often suspended in stasis fields. Such fields thus have the additional property of protecting non-living materials from deterioration. This time dilation can be, from an in-universe perspective, absolute; something thrown into the field, has the field triggered and then reactivated, would fly out as if nothing had happened. Storylines using such fields of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychokinesis
Psychokinesis (from grc, ψυχή, , soul and grc, κίνησις, , movement, label=ㅤ), or telekinesis (from grc, τηλε, , far off and grc, κίνησις, , movement, label=ㅤ), is a hypothetical psychic ability allowing a person to influence a physical system without physical interaction. Psychokinesis experiments have historically been criticized for lack of proper controls and repeatability. There is no good evidence that psychokinesis is a real phenomenon, and the topic is generally regarded as pseudoscience. Etymology The word ''psychokinesis'' was coined in 1914 by American author Henry Holt in his book ''On the Cosmic Relations''. The term is a compound of the Greek words ψυχή (''psyche'') – meaning "mind", "soul", "spirit", or "breath" – and κίνησις (''kinesis'') – meaning "motion" or "movement". The American parapsychologist J. B. Rhine coined the term ''extra-sensory perception'' to describe receiving information paranormally from an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force Field (technology)
In speculative fiction, a force field, sometimes known as an energy shield, force shield, energy bubble or deflector shield, is a barrier made of things like energy, negative energy, dark energy, electromagnetic fields, gravitational fields, electric fields, quantum fields, plasma, particles, radiation, solid light, or pure force. It protects a person, area, or object from attacks or intrusions or even deflects energy attacks back at the attacker. This fictional technology is created as a field of energy without mass that acts as a wall, so that objects affected by the particular force relating to the field are unable to pass through the field and reach the other side, are deflected or destroyed. Actual research in the 21st century has looked into the potential to deflect radiation or cosmic rays, but also more extensive shielding. This concept has become a staple of many science-fiction works, so much so that authors frequently do not even bother to explain or justify them ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force
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 (e.g. moving from a state of rest), 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 (formerly ). The original form of Newton's second law states that the net force acting upon an object is equal to the rate at which its momentum changes with time. If the mass of the object is constant, this law implies that the acceleration of an object is directly proportional to the net force acting on the object, is in the direction of the net force, and is inversely proportional to the mass of the object. Concepts related to force include: thrust, which increases the velocity of an object; drag, which decreases the velocity of an object; and torque, which pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field Line
A field line is a graphical visual aid for visualizing vector fields. It consists of an imaginary directed line which is tangent to the field vector at each point along its length. A diagram showing a representative set of neighboring field lines is a common way of depicting a vector field in scientific and mathematical literature; this is called a field line diagram. They are used to show electric fields, magnetic fields, and gravitational fields among many other types. In fluid mechanics field lines showing the velocity field of a fluid flow are called streamlines. Definition and description A vector field defines a direction and magnitude at each point in space. A field line for that vector field may be constructed by starting at a point and tracing a line through space that follows the direction of the vector field, by making the field line tangent to the field vector at each point. A field line is usually shown as a directed line segment, with an arrow indicatin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conservative Force
In physics, a conservative force is a force with the property that the total work done in moving a particle between two points is independent of the path taken. Equivalently, if a particle travels in a closed loop, the total work done (the sum of the force acting along the path multiplied by the displacement) by a conservative force is zero. A conservative force depends only on the position of the object. If a force is conservative, it is possible to assign a numerical value for the potential at any point and conversely, when an object moves from one location to another, the force changes the potential energy of the object by an amount that does not depend on the path taken, contributing to the mechanical energy and the overall conservation of energy. If the force is not conservative, then defining a scalar potential is not possible, because taking different paths would lead to conflicting potential differences between the start and end points. Gravitational force is an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Momentum
In Newtonian mechanics, momentum (more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. If is an object's mass and is its velocity (also a vector quantity), then the object's momentum is : \mathbf = m \mathbf. In the International System of Units (SI), the unit of measurement of momentum is the kilogram metre per second (kg⋅m/s), which is equivalent to the newton-second. Newton's second law of motion states that the rate of change of a body's momentum is equal to the net force acting on it. Momentum depends on the frame of reference, but in any inertial frame it is a ''conserved'' quantity, meaning that if a closed system is not affected by external forces, its total linear momentum does not change. Momentum is also conserved in special relativity (with a modified formula) and, in a modified form, in electrodynamics, quantum mechanics, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velocity
Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies. Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called , being a coherent derived unit whose quantity is measured in the SI (metric system) as metres per second (m/s or m⋅s−1). For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector. If there is a change in speed, direction or both, then the object is said to be undergoing an ''acceleration''. Constant velocity vs acceleration To have a ''constant velocity'', an object must have a constant speed in a constant direction. Constant directi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Integral
In mathematics, a line integral is an integral where the function to be integrated is evaluated along a curve. The terms ''path integral'', ''curve integral'', and ''curvilinear integral'' are also used; ''contour integral'' is used as well, although that is typically reserved for line integrals in the complex plane. The function to be integrated may be a scalar field or a vector field. The value of the line integral is the sum of values of the field at all points on the curve, weighted by some scalar function on the curve (commonly arc length or, for a vector field, the scalar product of the vector field with a differential vector in the curve). This weighting distinguishes the line integral from simpler integrals defined on intervals. Many simple formulae in physics, such as the definition of work as W=\mathbf\cdot\mathbf, have natural continuous analogues in terms of line integrals, in this case \textstyle W = \int_L \mathbf(\mathbf)\cdot d\mathbf, which computes the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
