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.
Other articles related to "radio waves, radio, waves, wave":
... Radio frequency (RF) energy has been used in medical treatments for over 75 years generally for minimally invasive surgeries and coagulation, including the treatment of sleep apnea ... Magnetic resonance imaging (MRI) uses radio frequency waves to generate images of the human body ...
... In 1981, Bo Thidé discovered electromagnetic emissions stimulated by powerful radio waves in the ionosphere during experiments in August 1981 at the EISCAT facility in Tromsø, Norway ... that the plasma turbulence excited by powerful radio waves in the ionosphere radiates secondary electromagnetic radiation that can be detected and analysed on the ground ... Lundborg on a highly accurate analytic approximation method to calculate the full three-dimensional wave pattern, spin angular momentum (polarization) and other properties of radio waves propagating in an inhomogeneous ...
... Radio wavelengths are much longer than optical wavelengths, and the observing stations in radio astronomical interferometers are correspondingly further apart ... distances do not always allow any usable transmission of radio waves received at the telescopes to some central interferometry point ... For this reason many telescopes instead record the radio waves onto a storage medium ...
... Radio waves are affected by just about everything around us ... Magnetic waves can pass through almost anything, even rock ... An RF signal falls off as 1/r, whereas the strength of a magnetic wave falls off far faster at the rate of 1/r³ ...
... Submarines are shielded by seawater from all ordinary radio signals, and therefore are cut off from communication with military command authorities while submerged ... The lower the frequency, the deeper radio waves are able to penetrate ocean water ... Waves in the very low frequency (VLF) range of 3 kHz to 30 kHz are able to penetrate to a depth of about 10 to 30 meters, and since WWII navies have used VLF ...
Famous quotes containing the words waves and/or radio:
“Come unto these yellow sands,
And then take hands.
Curtsied when you have and kissed
The wild waves whist,
Foot it featly here and there;
And, sweet sprites, the burden bear.”
—William Shakespeare (15641616)
“... the ... radio station played a Chopin polonaise. On all the following days news bulletins were prefaced by Chopinpreludes, etudes, waltzes, mazurkas. The war became for me a victory, known in advance, Chopin over Hitler.”
—Margaret Anderson (18861973)