Radio waves are short on history (discovered only a century ago), but they're long on use. They were first used early in the 20th century with the invention of the telegraph. During World War I, the military used radio waves in the form of radar to locate ships. By 1930, though, radio stations were broadcasting all over Europe and America and the radio receiver was a common household item. Today, the field of radio communications provides the global community with everything from microwave ovens to wireless computer networks.
AM and FM Radio
Radio waves are used for commercial AM and FM broadcasting. Citizens Band (CB) is a specific range of radio frequencies set aside for short-range public communication uses. Digital radio encodes numerical sequences that are sent via radio waves. Less familiar, perhaps, are the VHF AM and shortwave radios used by aviators and ships at sea to communicate with land-based operations.
Radar is a type of radio wave commonly used by commercial and military ships and airplanes for navigation, weather data and global positioning. Radar is also used on both commercial and private vessels to locate schools of fish.
Television antennas receive voice and picture in the form of AM and FM radio waves, while digital television uses an AM radio signal to transmit numerical (digital) codes.
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Satellite navigation systems use radio waves to signal their position to computers on Earth and radio waves enable people to communicate with space probes in the farthest reaches of the solar system.
Cell phones and satellite phones use radio waves to transmit to telephone networks that relay the signal to its destination. Radio waves enable emergency services to use cell phones for valuable communications in areas where wired technology is unavailable and satellite phones are used where cell phone service is unavailable.
Radio communication is also used for wireless applications, from remote control cars and airplanes to the remote control of robotics used to disarm explosive devices by police and military bomb squads. At home, wireless technology keeps computers connected to the Internet and intense radio waves, called microwaves, cook food.
Astronomers use radio telescopes to pick up signals transmitted from distance star systems. Radio astronomy is responsible for the discovery of pulsars and quasars and aids scientists in the exploration of the universe and their understanding of its beginnings.
Wildlife management teams track wild animals using radio telemetry, although it wasn't until 2005 that the Federal Communications Commission allowed it to be used for tracking birds. Animal tracking provides management teams with information about herd sizes and migration patterns.