Radio-The Second Revolution by Nur alia mursyida discusses the history of using radio in education from the 1920s to present day. In the 1920s, US visionaries saw potential for radio in teaching. Radio became integral to life in developed countries in the 1930s. Early US efforts using radio in schools were limited and complemented commercial radio stations. Governments soon recognized radio's power for public use. Usage had constraints like small lesson times, lack of control over PA systems and lessons. Technology advanced from analog to digital radio since the 2000s.