It was first consciously applied to modern physics by Frederick Soddy when he, along with Ernest Rutherford in 1901, discovered that radioactive thorium was converting itself into radium. At the moment of realization, Soddy later recalled, he shouted out: "Rutherford, this is transmutation!" Rutherford snapped back, "For Christ's sake, Soddy, don't call it transmutation. They'll have our heads off as alchemists."