electromagnetism

The unified field theory of electric and magnetic interactions, described by Maxwell’s equations.

• electric field: generated by charges, exerts force on other charges
• magnetic field: generated by moving charges and changing electric fields
• Maxwell’s equations unify electricity, magnetism, and light into one framework
• radiation is self-propagating oscillation of electromagnetic field
• light is an electromagnetic wave traveling at the speed of light in spacetime
• electromagnetic force is one of four fundamental forces — see force
• basis for optics, electronics, and quantum mechanics via quantum electrodynamics
• spectrum spans radio, microwave, infrared, visible light, ultraviolet, X-ray, gamma — see radiation