|unified field theory |
A theory that explains the four basic forces of nature (electromagnetism, gravity, strong force, and weak force) as manifestations of a single physical principle. No unified field theory that has been proposed so far has gained broad acceptance. Also called grand unified theory, theory of everything.
Any theory in which two seemingly different forces are seen to be fundamentally identical. Maxwell's equations express a unified field theory that demonstrates the basic identity of electricity and magnetism, and the standard model postulates a basic identity for the strong force, the weak force, and electromagnetism.