A wave that travels though space at the speed of light, consisting of an electrical field that periodically grows and dies, alternating with a magnetic field that periodically dies and grows. Electromagnetic waves carry energy and momentum, which may be imparted when it interacts with matter. In order of increasing frequency, the electromagnetic spectrum includes radio waves, microwaves, terahertz radiation, infrared radiation, visible light, ultraviolet radiation, x-rays and gamma rays.