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Four-minute Warning
The four-minute warning was a public alert system conceived by the British Government during the Cold War and operated between 1953 and 1992. The name derived from the approximate length of time from the point at which a Soviet nuclear missile attack against the United Kingdom could be confirmed and the impact of those missiles on their targets. The population was to be notified by means of air raid sirens, television and radio, and urged to seek cover immediately. In practice, the warning would have been more likely three minutes or less. The warning system Basic details The warning would be initiated by the detection of inbound missiles and aircraft targeted at the United Kingdom. Early in the Cold War, Jodrell Bank was used to detect and track incoming missiles, while continuing to be used for astronomical research. Throughout the Cold War, there was a conflict between the Royal Air Force and the Home Office about who was in charge of the warning system. This was not fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Politics Of The United Kingdom
The United Kingdom is a unitary state with devolution that is governed within the framework of a parliamentary democracy under a constitutional monarchy in which the monarch, currently Charles III, King of the United Kingdom, is the head of state while the Prime Minister of the United Kingdom, Rishi Sunak, is the head of government. Executive power is exercised by the British government, on behalf of and by the consent of the monarch, and the devolved governments of Scotland, Wales and Northern Ireland. Legislative power is vested in the two chambers of the Parliament of the United Kingdom, the House of Commons and the House of Lords, as well as in the Scottish, Northern Irish and Welsh parliaments. The British political system is a two party system. Since the 1920s, the two dominant parties have been the Conservative Party and the Labour Party. Before the Labour Party rose in British politics, the Liberal Party was the other major political party, along with the Conserv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electromagnetic Pulse
An electromagnetic pulse (EMP), also a transient electromagnetic disturbance (TED), is a brief burst of electromagnetic energy. Depending upon the source, the origin of an EMP can be natural or artificial, and can occur as an electromagnetic field, as an electric field, as a magnetic field, or as a conducted electric current. The electromagnetic interference caused by an EMP disrupts communications and damages electronic equipment; at higher levels of energy, an EMP such as a lightning strike can physically damage objects such as buildings and aircraft. The management of EMP effects is a branch of electromagnetic compatibility (EMC) engineering. EMP weapons are designed to deliver the damaging effects of a high-energy EMP that will disrupt unprotected infrastructure in the country, thus the employment of an EMP weapon against a country is the scenario of war most likely to collapse the functionality of the electrical network of the country. General characteristics An electrom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Civil Defence
Civil defense ( en, region=gb, civil defence) or civil protection is an effort to protect the citizens of a state (generally non-combatants) from man-made and natural disasters. It uses the principles of emergency operations: prevention, mitigation, preparation, response, or emergency evacuation and recovery. Programs of this sort were initially discussed at least as early as the 1920s and were implemented in some countries during the 1930s as the threat of war and aerial bombardment grew. Civil-defense structures became widespread after authorities recognised the threats posed by nuclear weapons. Since the end of the Cold War, the focus of civil defense has largely shifted from responding to military attack to dealing with emergencies and disasters in general. The new concept is characterised by a number of terms, each of which has its own specific shade of meaning, such as '' crisis management'', ''emergency management'', ''emergency preparedness'', ''contingency planning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postmaster
A postmaster is the head of an individual post office, responsible for all postal activities in a specific post office. When a postmaster is responsible for an entire mail distribution organization (usually sponsored by a national government), the title of Postmaster General is commonly used. Responsibilities of a postmaster typically include management of a centralized mail distribution facility, establishment of letter carrier routes, supervision of letter carriers and clerks, and enforcement of the organization's rules and procedures. The postmaster is the representative of the Postmaster General in that post office. In Canada, many early places are named after the first postmaster. History In the days of horse-drawn carriages, a postmaster was an individual from whom horses and/or riders (known as postilions or "post-boys") could be hired. The postmaster would reside in a "post house". The first Postmaster General of the United States was the notable founding father, B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Police Station
A police station (sometimes called a "station house" or just "house") is a building which serves to accommodate police officers and other members of staff. These buildings often contain offices and accommodation for personnel and vehicles, along with locker rooms, temporary holding cells and interview/interrogation rooms. Names Large departments may have many stations to cover the area they serve. The names used for these facilities include: *Barracks for many American state police and highway patrol stations and in Ireland *District office, typically used by American state police forces like the California Highway Patrol, but also used by smaller departments like the Calgary Police Service *Precinct house, or precinct, for some urban police departments in the United States such as the New York City Police Department, Memphis Police Department, and Newark Police Department, where stations are in charge of precincts *Police house *Police office, especially in Scotland *Statio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speaking Clock
A speaking clock or talking clock is a live or recorded human voice service, usually accessed by telephone, that gives the correct time. The first telephone speaking clock service was introduced in France, in association with the Paris Observatory, on 14 February 1933. The format of the service is similar to that of radio time signal services. At set intervals (''e.g.'' ten seconds) a voice announces (for example) "At the third stroke, the time will be twelve forty-six and ten seconds...", with three beeps following. Some countries have sponsored time announcements and include the sponsor's name in the message. List by country Australia In Australia, the number 1194 was the speaking clock in all areas. The service started in 1953 by the Post Master General's Department, originally to access the talking clock on a rotary dial phone, callers would dial "B074", during the transition from a rotary dial to a DTMF based phone system, the talking clock number changed from "B074" to 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Raid Siren
A civil defense siren, also known as an air-raid siren or tornado siren, is a siren used to provide an emergency population warning to the general population of approaching danger. It is sometimes sounded again to indicate the danger has passed. Some sirens, especially within small towns, are also used to call the volunteer fire department when needed. Initially designed to warn city dwellers of air raids in World War II, they were later used to warn of nuclear attack and natural destructive weather patterns, such as tornadoes. The generalized nature of sirens led to many of them being replaced with more specific warnings, such as the broadcast-based Emergency Alert System and the Cell Broadcast-based Wireless Emergency Alerts and EU-Alert mobile technologies. A mechanical siren generates sound by spinning a slotted chopper wheel to interrupt a stream of air at a regular rate. Modern sirens can develop a sound level of up to 135 decibels at . The Chrysler air raid sir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
