One of the four known basic forces in the universe.
Electromagnetism is responsible for interactions between charged particles that occur because of their charge, and for the emission and absorption of photons ( electromagnetic radiation ). The phenomena of electricity and magnetism are consequences of this force, and the relationships between them were first described by James Clerk Maxwell in the 1860s. The physical description of electromagnetism has since been combined with quantum mechanics into the theory of quantum electrodynamics . The electromagnetic force is about 10 36 times as strong as the gravitational force (see gravitation ), but significantly weaker than both the weak force and the strong force .