STEVE EMBER: And I’m Steve Ember with EXPLORATIONS in VOA Special English. Today we tell about the history of radio and the latest technology. (MUSIC) SHIRLEY GRIFFITH: Our story begins in Britain in eighteen seventy-three. A scientist named James Maxwell wrote a mathematical theory about a kind of energy. He called this energy electromagnetic waves. His theory said this kind of energy could pass unseen through the air. James Maxwell was not able to prove his idea. Other scientists could not prove it either until German scientist Heinrich Hertz tried an experiment around eighteen eighty-seven. STEVE EMBER: Hertz’s experiment sounds very simple. He used two pieces of metal placed close together. He used electricity to make a spark jump between the two pieces of metal. He also built a simple receiver made of wire that was turned many times in a circle or looped. At the ends of the loop were small pieces of