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:

v t e Major branches of physics
Divisions	Pure Applied Engineering
Approaches	Experimental Theoretical Computational
Classical	Classical mechanics Newtonian Analytical Celestial Continuum Acoustics Classical electromagnetism Classical optics Ray Wave Thermodynamics Statistical Non-equilibrium
Modern	Relativistic mechanics Special General Nuclear physics Quantum mechanics Particle physics Atomic, molecular, and optical physics Atomic Molecular Modern optics Condensed matter physics
Interdisciplinary	Astrophysics Atmospheric physics Biophysics Chemical physics Geophysics Materials science Mathematical physics Medical physics Ocean physics Quantum information science
Related	History of physics Nobel Prize in Physics Philosophy of physics Physics education Timeline of physics discoveries

See also