Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies from 300 GHz to as low as 3 kHz, and corresponding wavelengths from 1 millimeter to 100 kilometers. Like all other electromagnetic waves, they travel at the speed of light. Naturally occurring radio waves are made by lightning, or by astronomical objects. Artificially generated radio waves are used for fixed and mobile radio communication, broadcasting, radar and other navigation systems, communications satellites, computer networks and innumerable other applications. Different frequencies of radio waves have different propagation characteristics in the Earth's atmosphere; long waves may cover a part of the Earth very consistently, shorter waves can reflect off the ionosphere and travel around the world, and much shorter wavelengths bend or reflect very little and travel on a line of sight.
Read more about Radio Waves: Discovery and Utilization, Propagation, Speed, Wavelength and Frequency, Radio Communication, In Medicine
Famous quotes containing the words radio and/or waves:
“... the ... radio station played a Chopin polonaise. On all the following days news bulletins were prefaced by Chopin—preludes, etudes, waltzes, mazurkas. The war became for me a victory, known in advance, Chopin over Hitler.”
—Margaret Anderson (1886–1973)
“It is only when we are very happy that we can bear to gaze merrily upon the vast and limitless expanse of water, rolling on and on with such persistent, irritating monotony, to the accompaniment of our thoughts, whether grave or gay. When they are gay, the waves echo their gaiety; but when they are sad, then every breaker, as it rolls, seems to bring additional sadness, and to speak to us of hopelessness and of the pettiness of all our joys.”
—Emmuska, Baroness Orczy (1865–1947)