Radio And The Electromagnetic Spectrum
Radio utilizes a small part of the electromagnetic spectrum, the set of related wave-based phenomena that includes radio along with infrared light, visible light, ultraviolet light, x rays, and gamma rays. Picture the electromagneticspectrum as a piano keyboard: radio will be located where the piano keys produce the low frequency musical notes. Radio waves have lengths from many miles down to a fraction of a foot.
Science EncyclopediaScience & Philosophy: Quantum electronics to ReasoningRadio - The History Of Radio, Radio And The Electromagnetic Spectrum, How Radio Signals Are Created, Modulation - Demodulation