Field (physics)

In physics, a field is an assignment of a quantity to every point in space. For example, one can speak of a gravitational field, which assigns a gravitational potential to each point in space. The isotherms and isobars shown in weather bulletins every day on TV are a picture of a temperature field or the air pressure field on the surface of the earth or the isophons of the curves of equal loudness level. Fields are classified by space-time symmetries or by internal symmetries.

Related Topics:
Physics - Gravitational field - Isotherms - Isobars - Isophons - Symmetries

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Field theory usually refers to a construction of the dynamics of a field, ie, a specification of how a field changes with time. Usually this is done by writing a Lagrangian or a Hamiltonian of the field, and treating it as the classical mechanics (or quantum mechanics) of a system with an infinite number of degrees of freedom.

Related Topics:
Lagrangian - Hamiltonian - Classical mechanics - Quantum mechanics - Degrees of freedom

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