Mexico City

Mexico City (Spanish: Ciudad de México  audio  American Spanish: [sjuˈða(ð) ðe ˈméxiko]; abbreviated as "CDMX") is the capital of Mexico. Mexico City is the country's largest city as well as its most important political, cultural, educational and financial center.

As an "alpha" global city Mexico City is one of the most important financial centers in the Americas. It is located in the Valley of Mexico (Valle de México), a large valley in the high plateaus at the center of Mexico, at an altitude of 2,240 metres (7,350 ft). The city consists of sixteen municipalities (previously called boroughs).

The 2009 estimated population for the city proper was around 8.84 million people, with a land area of 1,485 square kilometres (573 sq mi). According to the most recent definition agreed upon by the federal and state governments, the Greater Mexico City population is 21.2 million people, making it the largest metropolitan area in the western hemisphere, the eleventh-largest agglomeration, and the largest Spanish-speaking city in the world.

Mexico

Coordinates: 23°N 102°W / 23°N 102°W / 23; -102

Mexico (ⁱ/ˈmɛksᵻkoʊ/; Spanish: México [ˈmexiko]), officially the United Mexican States (Spanish: Estados Unidos Mexicanos,  listen ), is a federal republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of Mexico. Covering almost two million square kilometres (over 760,000 sq mi), Mexico is the fifth largest country in the Americas by total area and the 13th largest independent nation in the world. With an estimated population of over 120 million, it is the eleventh most populous country and the most populous Spanish-speaking country in the world and the second most populous country in Latin America. Mexico is a federation comprising thirty-two states, including Mexico City, its capital and largest city, which is also a state.

City

A city is a large and permanent human settlement. Although there is no agreement on how a city is distinguished from a town in general English language meanings, many cities have a particular administrative, legal, or historical status based on local law.

Cities generally have complex systems for sanitation, utilities, land usage, housing, and transportation. The concentration of development greatly facilitates interaction between people and businesses, benefiting both parties in the process, but it also presents challenges to managing urban growth.

A big city or metropolis usually has associated suburbs and exurbs. Such cities are usually associated with metropolitan areas and urban areas, creating numerous business commuters traveling to urban centers for employment. Once a city expands far enough to reach another city, this region can be deemed a conurbation or megalopolis. In terms of population, the largest city proper is Shanghai, while the fastest-growing is Dubai.

Origins

There is not enough evidence to assert what conditions gave rise to the first cities. Some theorists have speculated on what they consider suitable pre-conditions and basic mechanisms that might have been important driving forces.

Radio

Radio is the use of radio waves is to carry information, such as sound, by systematically modulating some property of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.

Radio systems need a transmitter to modulate (change) some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation (which can be frequency modulation or phase modulation). Radio systems also need an antenna to convert electric currents into radio waves, and vice versa. An antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual stations to be selected. The electromagnetic wave is intercepted by a tuned receiving antenna. A radio receiver receives its input from an antenna and converts it into a form usable for the consumer, such as sound, pictures, digital data, measurement values, navigational positions, etc. Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum.

Radio Moscow

Radio Moscow (Russian: Pадио Москва, tr. Radio Moskva), also known as Radio Moscow World Service, was the official international broadcasting station of the Union of Soviet Socialist Republics. At its peak, Radio Moscow broadcast in over 70 languages using transmitters in the Soviet Union, Eastern Europe, and Cuba.

Radio Moscow's interval signal was 'Wide Is My Motherland' (Russian: Широка страна моя родная, tr. Shiroka strana moya rodnaya).

History

Early years

Its first emission in a foreign language was in German on 29 October 1929, and later in English and French. Previously, Radio Moscow broadcast in 1922 with a transmitter station RV-1 in the Moscow region, and a second broadcasting centre came on air at Leningrad in 1925. By 1939, Radio Moscow was broadcasting (on mediumwave and shortwave) in English, French, Indonesian, German, Italian and Arabic. Radio Moscow did express concern over the rise of German dictator Adolf Hitler during the 1930s, and its Italian mediumwave service specifically was jammed by an order of Italian dictator Benito Mussolini during the late 1930s.