Often regarded as one of the most innovative and inventive individuals in the history of the sciences. He was the first to introduce the alternating-current machine, removing the need for commutator bars of dc machines. After emigrating to the United States in 1884, he sold a number of his patents on ac machines, transformers, and induction coils (including the Tesla coil as we know it today) to the Westinghouse Electric Company. Some say that his most important discovery was made at his laboratory in Colorado Springs, where in 1900 he discovered terrestrial stationary waves. The range of his discoveries and inventions is too extensive to list here but extends from lighting systems to polyphase power systems to a wireless world broadcasting system.