Radio Waves

Radio waves are a form of electromagnetic radiation with long wavelengths and low frequencies. The radio section of the electromagnetic spectrum covers a fairly wide band and includes waves with frequencies ranging from about 10 kilohertz to about 60,000 megahertz (which correspond to wavelengths between 98,000 ft, or 30,000 m, and 0.2 in, or 0.5 cm). The commercial value of radio waves as a means of transmitting sounds was first appreciated by the Italian inventor Guglielmo Marconi in the 1890s. Marconi's invention led to the wireless telegraph, the radio, and eventually to such variations as the AM radio, FM radio, and CB (citizen's band) radio.