Radio

Radio transmits and receives information through electromagnetic waves, commonly carrying audio from a broadcaster to receivers over distance.

Amplitude modulation: A modulation method that encodes a signal by varying a carrier wave’s amplitude. AM changes the carrier’s strength to carry audio, making it especially vulnerable to static.
James Clerk Maxwell: A Scottish physicist whose equations unified electricity and magnetism and predicted electromagnetic waves. Maxwell’s theory supplied the foundation for waves later used in radio communication.
AM broadcasting: Radio broadcasting that uses amplitude modulation to transmit audio. AM stations deliver audio over assigned frequencies, often across wide geographic areas.
Television broadcasting: The transmission of audiovisual programs from stations to television receivers. Television adds moving images to the one-to-many broadcast model radio established.
Frequency modulation: A modulation method that encodes a signal by varying a carrier wave’s frequency. FM carries audio through frequency changes and generally resists amplitude noise.
Heinrich Hertz: A German physicist who experimentally demonstrated electromagnetic waves in the 1880s. Hertz confirmed that electromagnetic waves could be generated and detected.
FM broadcasting: Radio broadcasting that uses frequency modulation to transmit audio. FM stations became a major format for high-fidelity music and local programming.
Podcasting: The distribution of episodic audio files or streams, commonly accessed on demand over the internet. Podcasts offer on-demand audio, unlike radio’s traditionally scheduled broadcasts.
Radio transmitter: An electronic device that generates and radiates modulated radio-frequency signals. The transmitter converts a station’s audio program into a signal an antenna can radiate.
Guglielmo Marconi: An Italian inventor who developed practical wireless telegraphy systems and commercialized long-distance radio communication. Marconi’s wireless systems helped establish radio transmission as a practical technology.

Linked from 22 pages