In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:electromagnetic radiation, such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ) particle radiation, such as alpha radiation (α), beta radiation (β), proton radiation and neutron radiation acoustic radiation, such as ultrasound, sound, and seismic waves gravitational radiation, radiation that takes the form of gravitational waves, or ripples in the curvature of spacetime
