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- Field_(physics) abstract "A field is a physical quantity that has a value for each point in space and time. For example, in a weather forecast, the wind velocity is described by assigning a vector to each point in space. Each vector represents the speed and direction of the movement of air at that point.A field can be classified as a scalar field, a vector field, a spinor field or a tensor field according to whether the value of the field at each point is a scalar, a vector, a spinor or a tensor, respectively. For example, the Newtonian gravitational field is a vector field: specifying its value at a point in spacetime requires three numbers, the components of the gravitational field vector at that point. Moreover, within each category (scalar, vector, tensor), a field can be either a classical field or a quantum field, depending on whether it is characterized by numbers or quantum operators respectively.A field may be thought of as extending throughout the whole of space. In practice, the strength of every known field has been found to diminish with distance to the point of being undetectable. For instance, in Newton's theory of gravity, the gravitational field strength is inversely proportional to the square of the distance from the gravitating object. Therefore the Earth's gravitational field quickly becomes undetectable on cosmic scales.Defining the field as "numbers in space" shouldn't detract from the idea that it has physical reality. "It occupies space. It contains energy. Its presence eliminates a true vacuum." The field creates a "condition in space" such that when we put a particle in it, the particle "feels" a force.If an electrical charge is accelerated, the effects on another charge do not appear instantaneously. The first charge feels a reaction force, picking up momentum, but the second charge feels nothing until the influence, traveling at the speed of light, reaches it and gives it the momentum. Where is the momentum before the second charge moves? By the law of conservation of momentum it must be somewhere. Physicists have found it of "great utility for the analysis of forces" to think of it as being in the field.This utility leads to physicists believing that electromagnetic fields actually exist, making the field concept a supporting paradigm of the entire edifice of modern physics. That said, John Wheeler and Richard Feynman seriously considered Newton's pre-field concept of action at a distance (although they set it aside because of the ongoing utility of the field concept for research in general relativity and quantum electrodynamics)."The fact that the electromagnetic field can possess momentum and energy makes it very real... a particle makes a field, and a field acts on another particle, and the field has such familiar properties as energy content and momentum, just as particles can have".".
- Field_(physics) thumbnail Field-illustrations-add.png?width=300.
- Field_(physics) wikiPageExternalLink index.html.
- Field_(physics) wikiPageID "26998617".
- Field_(physics) wikiPageRevisionID "606445025".
- Field_(physics) align "center".
- Field_(physics) caption "E fields due to stationary electric charges and B fields due to stationary magnetic charges. In motion , an electric charge induces a B field while a magnetic charge induces an E field. Conventional current is used.".
- Field_(physics) caption "Top: E field due to an electric dipole moment d. Bottom left: B field due to a mathematical magnetic dipole m formed by two magnetic monopoles. Bottom right: B field due to a pure magnetic dipole moment m found in ordinary matter .".
- Field_(physics) direction "horizontal".
- Field_(physics) footer "The E fields and B fields due to electric charges and magnetic poles .".
- Field_(physics) hasPhotoCollection Field_(physics).
- Field_(physics) image "em dipoles.svg".
- Field_(physics) image "em monopoles.svg".
- Field_(physics) width "300".
- Field_(physics) width "350".
- Field_(physics) subject Category:Concepts_in_physics.
- Field_(physics) subject Category:Theoretical_physics.
- Field_(physics) type Abstraction100002137.
- Field_(physics) type Cognition100023271.
- Field_(physics) type Concept105835747.
- Field_(physics) type Content105809192.
- Field_(physics) type FundamentalPhysicsConcepts.
- Field_(physics) type Idea105833840.
- Field_(physics) type PsychologicalFeature100023100.
- Field_(physics) comment "A field is a physical quantity that has a value for each point in space and time. For example, in a weather forecast, the wind velocity is described by assigning a vector to each point in space. Each vector represents the speed and direction of the movement of air at that point.A field can be classified as a scalar field, a vector field, a spinor field or a tensor field according to whether the value of the field at each point is a scalar, a vector, a spinor or a tensor, respectively.".
- Field_(physics) label "Campo (fisica)".
- Field_(physics) label "Campo (física)".
- Field_(physics) label "Campo (física)".
- Field_(physics) label "Champ (physique)".
- Field_(physics) label "Feld (Physik)".
- Field_(physics) label "Field (physics)".
- Field_(physics) label "Pole (fizyka)".
- Field_(physics) label "Veld (natuurkunde)".
- Field_(physics) label "Поле (физика)".
- Field_(physics) label "مجال فيزيائي".
- Field_(physics) label "场 (物理)".
- Field_(physics) label "場".
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- Field_(physics) sameAs Campo_(fisica).
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- Field_(physics) sameAs 장_(물리학).
- Field_(physics) sameAs Veld_(natuurkunde).
- Field_(physics) sameAs Pole_(fizyka).
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- Field_(physics) sameAs Q185674.
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- Field_(physics) wasDerivedFrom Field_(physics)?oldid=606445025.
- Field_(physics) depiction Field-illustrations-add.png.
- Field_(physics) isPrimaryTopicOf Field_(physics).