field

A physical quantity assigned to every point in spacetime, mediating forces and interactions.

• gravitational field: generated by mass, described by gravity and general relativity
• electromagnetic field: generated by charges and currents — see electromagnetism
• quantum fields: fundamental entities in quantum mechanics; particles are excitations of fields
• scalar fields (Higgs, temperature), vector fields (electric, magnetic), tensor fields (metric of spacetime)
• field equations (Maxwell’s, Einstein’s) govern how fields evolve and interact
• energy and momentum are carried by fields themselves
• the field concept replaces action-at-a-distance with local, propagating interactions