Different discovery's of electromagnetic Radiation By xXJesus_ChristXx 1800 William Herschel, a British astronomer, discovered infra-red radiation (heat waves). 1801 German chemist Johann Ritter discovered UV radiation. 1885 James Maxwell, a British scientist, predicted the existence of continuous EM waves. 1887 German scientist Heinrich Hertz discovered radio waves. 1895 German physicist Wihelm Roentgen discovered x-rays. 1896 French physicist Henri Becquerel discovered radioactive rays emitted by uranium. 1898 Marie Curie discovered radium. 1900 Frenchman Paul Villard discovered gamma rays.