C'mon Radio, Let's Do The Twist. Broadcasting live from Italy: a new twist on radio that could pack more information into the airwaves. TESTING THE WAVES A radio broadcast 442 meters from a lighthouse on the island of San Giorgio Maggiore (right) to the Doge’s Palace in Venice (left) demonstrated a new way to twist these electromagnetic waves that could be useful for wireless networks and cell phone communications. © age fotostock / SuperStock THE DISH Radio waves bounced off this parabolic antennae twist like a spiral staircase. F. Radio. Etymology[edit] The etymology of "radio" or "radiotelegraphy" reveals that it was called "wireless telegraphy", which was shortened to "wireless" in Britain.
The prefix radio- in the sense of wireless transmission, was first recorded in the word radioconductor, a description provided by the French physicist Édouard Branly in 1897. It is based on the verb to radiate (in Latin "radius" means "spoke of a wheel, beam of light, ray"). The word "radio" also appears in a 1907 article by Lee De Forest. It was adopted by the United States Navy in 1912, to distinguish radio from several other wireless communication technologies, such as the photophone.
The term became common by the time of the first commercial broadcasts in the United States in the 1920s. Processes[edit] Transducing information such as sound into an electromagnetic pulse signal, which is then sent as an electromagnetic radio wave from a transmitter. Radio systems used for communications will have the following elements. Radio wave. 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 ranging from 1 millimeter (0.039 in) to 100 kilometers (62 mi). 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. See also[edit] Astronomers Find Mysterious Radio Burst. A new and intense type of radio burst has been discovered in archived views of the cosmos, astronomers revealed today.
The single, short-lived blast of radio waves likely occurred some 3 billion light-years from Earth, and it may signal a cosmic car crash of two neutron stars, the death throes of a black hole—or something else. "This is something that's completely unprecedented," said Duncan Lorimer, an astrophysicist at West Virginia University in Morgantown and the National Radio Astronomy Observatory who led the discovery-making team. He noted that radio-emitting pulsars send out similar emissions, but repeat them every few hours. "We're confused and excited, but it could open up a whole new research field," Lorimer told SPACE.com of the 5-millisecond blip on the cosmic radar screen. The discovery is detailed in the Sept. 27 issue of the online journal Science Express. Blast from beyond "We've looked at it for about 90 hours, and it definitely seems to be a singular event," he said.
Electromagnetic radiation. The electromagnetic waves that compose electromagnetic radiation can be imagined as a self-propagating transverse oscillating wave of electric and magnetic fields. This diagram shows a plane linearly polarized EMR wave propagating from left to right. The electric field is in a vertical plane and the magnetic field in a horizontal plane. The two types of fields in EMR waves are always in phase with each other with a fixed ratio of electric to magnetic field intensity.
Electromagnetic radiation (EM radiation or EMR) is a fundamental phenomenon of electromagnetism, behaving as waves propagating through space, and also as photon particles traveling through space, carrying radiant energy. In a vacuum, it propagates at a characteristic speed, the speed of light, normally in straight lines. EMR is emitted and absorbed by charged particles. In classical physics, EMR is considered to be produced when charged particles are accelerated by forces acting on them.
Physics[edit] Theory[edit]