An electromagnetic field (also EMF or EM field) is a physical field produced by moving electrically charged objects. It affects the behavior of charged objects in the vicinity of the field. The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction. It is one of the four fundamental forces of nature (the others are gravitation, the weak interaction, and the strong interaction).
The field can be viewed as the combination of an electric field and a magnetic field. The electric field is produced by stationary charges, and the magnetic field by moving charges (currents); these two are often described as the sources of the field. The way in which charges and currents interact with the electromagnetic field is described by Maxwell's equations and the Lorentz force law.
From a classical perspective, the electromagnetic field can be regarded as a smooth, continuous field, propagated in a wavelike manner; whereas from the perspective of quantum field theory, the field is seen as quantized, being composed of individual particles.
Read more about Electromagnetic Field: Structure of The Electromagnetic Field, Dynamics of The Electromagnetic Field, Electromagnetic Field As A Feedback Loop, Mathematical Description, Relation To and Comparison With Other Physical Fields, Health and Safety
Famous quotes containing the word field:
“The head must bow, and the back will have to bend,
Wherever the darkey may go;
A few more days, and the trouble all will end,
In the field where the sugar-canes grow.
A few more days for to tote the weary load,—
No matter, ‘t will never be light;
A few more days till we totter on the road:—
Then my old Kentucky home, good-night!”
—Stephen Collins Foster (1826–1884)