1860-1934

French physicist who discovered gamma radiation. During his study of nuclear reactions in 1900, Villard was the first to observe an emission, which he named gamma rays. He proposed that a gamma ray is radiation similar to light, rather than made up of particles like the previously observed nuclear reaction emissions, alpha and beta rays. Ernest Rutherford confirmed Villard's conclusion in 1914, showing that gamma rays are electromagnetic radiation with a much shorter wavelength than X-rays.