Field (physics)

In physics, a field is an assignment of a quantity to every point in space.

Physicists distinguish between three types of fields, in increasing generality:

• scalar fields, such as temperature,
• vector fields, such as the magnitude and direction of the force at each point in a magnetic field.
• tensor fields, such as the stress-energy tensor in general relativity.

Classically, field theory was first used to describe the behavior of particles in electric and magnetic fields. These were later unified into a single electromagnetic field.

The quantum mechanical analogue of field theory is called quantum field theory. Examples of quantum field theories include:

• quantum electrodynamics
• quantum chromodynamics
• electroweak force

See also

Physics: Coherent state, Gauge theory

List of electronics topics: Closed waveguide, Electric field, Electromagnetic radiation hazard, Far-field region, Flux, Fresnel zone, Magneto-optic effect, Mode field diameter, Near-field region, Speckle pattern, Surface wave

General subfields within physics
Classical mechanics | Condensed matter physics | Continuum mechanics | Electromagnetism | General relativity | Particle physics | Quantum field theory | Quantum mechanics | Solid state physics | Special relativity | Statistical mechanics | Thermodynamics