Gamma radiation, an aa kent as gamma rays, an denotit bi the Greek letter γ, refers tae electromagnetic radiation o extremely heich frequency an tharefore heich energy per photon. Gamma rays are ionisin radiation, an are sicweys biologically hazardous. Thay are classically produced bi the decay frae heich energy states o atomic nuclei (gamma decay), but are an aa creatit bi ither processes. Paul Villard, a French chemist an pheesicist, discovered gamma radiation in 1900, while studyin radiation emitted frae radium. Villard's radiation wis named "gamma rays" bi Ernest Rutherford in 1903.