Prague
Prague is the capital and largest city in the Czech Republic, the 14th largest city in the European Union and the historical capital of Bohemia. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of 2.6 million. The city has a temperate climate, with chilly winters. Prague has been a political and economic centre of central Europe complete with a rich history. Founded during the Romanesque and flourishing by the Gothic and Baroque eras, Prague was the capital of the Kingdom of Bohemia and the main residence of several Holy Roman Emperors, most notably of Charles IV, it was an important city to its Austro-Hungarian Empire. The city played major roles in the Bohemian and Protestant Reformation, the Thirty Years' War and in 20th-century history as the capital of Czechoslovakia, during both World Wars and the post-war Communist era. Prague is home to a number of well-known cultural attractions, many of which survived the violence and destruction of 20th-century Europe.
Main attractions include Prague Castle, Charles Bridge, Old Town Square with the Prague astronomical clock, the Jewish Quarter, Petřín hill and Vyšehrad. Since 1992, the extensive historic centre of Prague has been included in the UNESCO list of World Heritage Sites; the city has more than ten major museums, along with numerous theatres, galleries and other historical exhibits. An extensive modern public transportation system connects the city, it is home to a wide range of public and private schools, including Charles University in Prague, the oldest university in Central Europe. Prague is classified as an "Alpha −" global city according to GaWC studies and ranked sixth in the Tripadvisor world list of best destinations in 2016, its rich history makes it a popular tourist destination and as of 2017, the city receives more than 8.5 million international visitors annually. Prague is the fourth most visited European city after London and Rome. During the thousand years of its existence, the city grew from a settlement stretching from Prague Castle in the north to the fort of Vyšehrad in the south, becoming the capital of a modern European country, the Czech Republic, a member state of the European Union.
The region was settled as early as the Paleolithic age. A Jewish chronicler David Solomon Ganz, citing Cyriacus Spangenberg, claimed that the city was founded as Boihaem in c. 1306 BC by an ancient king, Boyya. Around the fifth and fourth century BC, a Celts tribe appeared in the area establishing settlements including an oppidum in Závist, a present-day suburb of Prague, naming the region of Bohemia, which means "home of the Boii people". In the last century BC, the Celts were driven away by Germanic tribes, leading some to place the seat of the Marcomanni king, Maroboduus, in southern Prague in the suburb now called Závist. Around the area where present-day Prague stands, the 2nd century map drawn by Ptolemaios mentioned a Germanic city called Casurgis. In the late 5th century AD, during the great Migration Period following the collapse of the Western Roman Empire, the Germanic tribes living in Bohemia moved westwards and in the 6th century, the Slavic tribes settled the Central Bohemian Region.
In the following three centuries, the Czech tribes built several fortified settlements in the area, most notably in the Šárka valley and Levý Hradec. The construction of what came to be known as Prague Castle began near the end of the 9th century, growing a fortified settlement that existed on the site since the year 800; the first masonry under Prague Castle dates from the year 885 at the latest. The other prominent Prague fort, the Přemyslid fort Vyšehrad, was founded in the 10th century, some 70 years than Prague Castle. Prague Castle is dominated by the cathedral, which began construction in 1344, but wasn't completed until the 20th century; the legendary origins of Prague attribute its foundation to the 8th century Czech duchess and prophetess Libuše and her husband, Přemysl, founder of the Přemyslid dynasty. Legend says that Libuše came out on a rocky cliff high above the Vltava and prophesied: "I see a great city whose glory will touch the stars." She ordered a town called Praha to be built on the site.
The region became the seat of the dukes, kings of Bohemia. Under Holy Roman Emperor Otto II the area became a bishopric in 973; until Prague was elevated to archbishopric in 1344, it was under the jurisdiction of the Archbishopric of Mainz. Prague was an important seat for trading where merchants from all of Europe settled, including many Jews, as recalled in 965 by the Hispano-Jewish merchant and traveller Ibrahim ibn Ya'qub; the Old New Synagogue of 1270 still stands in the city. Prague was once home to an important slave market. At the site of the ford in the Vltava river, King Vladislaus I had the first bridge built in 1170, the Judith Bridge, named in honour of his wife Judith of Thuringia; this bridge was destroyed by a flood in 1342, but some of the original foundation stones of that bridge remain in the river. It was named the Charles Bridge. In 1257, under King Ottokar II, Malá Strana was founded in Prague on the site of an older village in what would become the Hradčany area; this was the district of the German people, who had the right to administer the law autonomously, pursuant to Magdeburg rights.
The new district was on the bank opposite of the Staré Město, which had borough status and was bordered by a line of walls and fortifications. Prague flourished dur
WE.177
The WE.177 styled as WE 177, sometimes as WE177, was a series of tactical and strategic nuclear weapons equipping the Royal Navy and the Royal Air Force. It was the primary air-dropped nuclear weapon in the UK from the late 1960s into the 1990s; the underlying design was based on the US W59, which the UK had gained as part of their involvement in the GAM-87 Skybolt program. The RAF was not happy with the primary stage of the W59, subject to accidental detonation when subject to mechanical shocks. Air Ministry Operational Requirement OR.1177 was issued for a new design using a less sensitive explosive, undertaken at the Atomic Weapons Research Establishment as "Cleo". When Skybolt was cancelled, the UK gained access to the UGM-27 Polaris missile and its W58 warhead, but they continued development of Cleo as a tactical weapon to replace Red Beard. A requirement for a much smaller tactical and anti-submarine weapon for Navy use was filled by using the new primary as a boosted fission weapon. Three versions were produced, A, B and C.
The first to be produced was the 450 kilotonnes of TNT WE.177B, which entered service with the RAF at RAF Cottesmore in September 1966. Further deliveries were delayed by the need to complete the warheads for the Polaris A3T; the Navy did not begin to receive its ~10 kt WE.177A's until 1969. The 190 kt C models for the RAF followed. All versions could be parachute retarded; the WE.177A, in anti-submarine mode, could be carried by helicopters and by the Ikara missile system. The Navy weapons were retired by 1992, all other weapons with the RAF were retired by 1998; when it was withdrawn in 1998, the WE.177 had been in service longer than any other British nuclear weapon. The WE.177 was the last nuclear bomb in service with the Royal Air Force, the last tactical nuclear weapon deployed by the United Kingdom. In May 1960, Prime Minister Harold Macmillan signed an agreement with President Eisenhower to purchase 144 AGM-48 Skybolt missiles for the UKs V bomber force. Along with the missiles, the UK would receive the design of the Skybolt's W59 warhead, much smaller and lighter than the smallest UK designs of the era.
The UK version would be known by the codename RE.179. However, the W59 primary used a polymer-bonded explosive. Since the late 1950s, they had been working on their own primary design, originally'Octopus', then'Super Octopus', that used more explosive and less fissile material, was shock-insensitive as well, they proposed adapting the Super Octopus design for use in RE.179, calling the new version'Cleo'. Cleo designs were tested underground at the Nevada Test Site in 1962; the secondary of RE.179 remained identical to the W59's, were known as'Simon' in WE.177B, as'Reggie' in the ET.317 version for UK Polaris. At the time, the UK's only tactical nuclear weapon was Red Beard, a large weapon of 2,000 pounds weight. While work continued on Cleo, it was decided to adapt it as a weapon of its own to replace Red Beard, as the'Improved Kiloton Weapon'; the adapted version of the primary, now the only part of the physics package, became'Katie'. Katie would be used in a new bomb casing to produce WE.177A, replacing Red Beard with a weapon of 1/3 the weight, much smaller size.
WE.177A would be used by the Royal Navy, both for surface attack, as well as a nuclear depth bomb, or NDB. When AGM-48 Skybolt was cancelled, part of the resulting Nassau Agreement was the replacement of Skybolt with the Polaris missile. Polaris A3T used its own warhead design, W58; the W58 was rejected by the British because it used PBX-9404 in its primary. The UK solution was to adapt their RE.179 for the UK Polaris, assigned the codename ET.317. The need for ET.317 warheads for UK Polaris was urgent, development of the Improved Kiloton Bomb was temporarily halted until the Polaris warhead programme was completed. To fill the gap until Polaris entered service, it was necessary to provide RAF strategic bombers with a suitable weapon that would allow them to penetrate Warsaw Pact defences at low-level, minimising attrition from air defences. WE.177 was adapted to produce a high-yield interim strategic weapon for the five-year period, while the Polaris submarine force was building. Halting work on the original WE.177, now known as the'A' model, a new version that used the W59 secondary, codenamed Simon, matched with a modified'Katie B' primary created WE.177B.
This version required a lengthened bomb casing, was somewhat longer and heavier than WE.177A. During the Chevaline program, the number of warheads on each Polaris missile was reduced from three to two; these now-redundant third warheads were adapted into the new WE.177C. This conversion consisted of removing the original primary, replacing them with Katie A from the WE.177As. The new warhead was placed in existing WE.177B casings, ballasted to have identical weight and ballistics as the WE.177B. Type A, B and C weapons were carried by strike aircraft, including the Avro Vulcan, de Havilland Sea Vixen, Blackburn Buccaneer, SEPECAT Jaguar, Panavia Tornado; the Royal Navy Sea Harrier carried only WE.177A, slung beneath the starboard wing. The B and C models were too large for this aircraft. At one time, eight Tornado squadrons were nuclear capable. Three paint schemes are known to have been used on WE.177. The drill weapon used for loadin
Supreme Allied Commander Europe
The Supreme Allied Commander Europe is the commander of the North Atlantic Treaty Organization's Allied Command Operations and head of ACO's headquarters, Supreme Headquarters Allied Powers Europe. The commander is based at SHAPE in Belgium. SACEUR is the second-highest military position within NATO, below only the Chairman of the NATO Military Committee in terms of precedence. SACEUR has always been held by a U. S. military officer, the position is dual-hatted with that of Commander of United States European Command. The current SACEUR, General Curtis M. Scaparrotti, has held the position since 4 May 2016. Since 2003 the Supreme Allied Commander Europe has served as the head of Allied Command Europe and the head of Allied Command Operations; the officeholders have been: The position of deputy head of Allied Command Europe – since 2003 known as deputy head of Allied Command Operations – has been held by the following officers. From January 1978 until June 1993 there were two Deputy SACEURs, one British and one German, but from July 1993 this reverted to a single Deputy SACEUR.
Supreme Allied Commander Secretary General of NATO Chairman of the NATO Military Committee Official website
Gloster Javelin
The Gloster Javelin is a twin-engined T-tailed delta-wing subsonic night and all-weather interceptor aircraft that served with Britain's Royal Air Force from the mid-1950s until the late 1960s. The last aircraft design to bear the Gloster name, it was introduced in 1956 after a lengthy development period and received several upgrades during its lifetime to its engines and weapons, which included the De Havilland Firestreak air-to-air missile; the Javelin was succeeded in the interceptor role by the English Electric Lightning, a supersonic aircraft capable of flying at more than double the Javelin's top speed, introduced into the RAF only a few years later. The Javelin served for much of its life alongside the Lightning. In the aftermath of the Second World War, Britain identified a threat posed by the jet-powered strategic bomber and atomic weaponry and thus placed a great emphasis on developing aerial supremacy through continuing to advance its fighter technology following the end of conflict.
Gloster Aircraft, having developed and produced the only Allied jet aircraft to be operational during the war, the Gloster Meteor, sought to take advantage of its expertise and responded to a 1947 Air Ministry requirement for a high-performance night fighter under Air Ministry specification F.44/46. The specification called for a two-seat night fighter, that would intercept enemy aircraft at heights of up to at least 40,000 feet, it would have to reach a maximum speed of 525 kn at this height, be able to perform rapid ascents and attain an altitude of 45,000 feet within ten minutes of engine ignition. Additional criteria given in the requirement included a minimum flight endurance of two hours, a takeoff distance of 1,500 yards, structural strength to support up to 4g manoeuvres at high speed and for the aircraft to incorporate airborne interception radar, multi-channel VHF radio and various navigational aids; the aircraft would be required to be economical to produce, at a rate of ten per month for an estimated total of 150 aircraft.
Gloster produced several design proposals in the hope of satisfying the requirement. P.228, drawn up in 1946, was a two-seat Meteor with swept wings. A similar design was offered to the Royal Navy as the P.231. The later-issued P.234 and P.238 of early 1947 had adopted many of the features that would be distinctive of the Javelin, including the large delta wing and tailplane. The two differed in role; the RAF requirements were subject to some changes in regards to radar equipment and armaments. On 13 April 1949, the Ministry of Supply issued instructions to two aircraft manufacturers, Gloster and de Havilland, to each construct four airworthy prototypes of their competing designs to meet the requirement, as well as one airframe each for structural testing; these prototype aircraft were the Gloster GA.5, designed by Richard Walker, the de Havilland DH.110, the latter of which held the advantage of being under consideration for the Royal Navy. Development was delayed through political cost-cutting measures, the number of prototypes being trimmed down to an unworkable level of two each before the decision was reversed.
The first prototype was completed in 1951. An unusual feature of the prototypes was the opaque canopy over the rear cockpit, it had been believed that visibility outside the cockpit was unnecessary and a hindrance to the observer. Following a month of ground testing, on 26 November 1951, the first prototype conducted its first flight at Moreton Valence airfield. Bill Waterton, Gloster's Chief Test Pilot, would describe the Javelin as being "as easy to fly as an Anson", although expressing concern over its inadequate power controls. Disaster nearly struck during one test flight when aerodynamic flutter caused the elevators to detach in mid-flight, he was awarded the George Medal for his actions to retrieve flight data from the burning aircraft. The second prototype received a modified wing in 1953. After initial testing by Waterton, it was passed to another Gloster test pilot, Peter Lawrence for his opinion. On 11 June 1953, the aircraft crashed during testing. Lawrence had ejected from the aircraft, but too late, was killed.
The Javelin had experienced a "deep stall". Without elevator control, Lawrence was unable to regain control and the aircraft dropped from the sky. A stall warning device was developed and implemented for the Javelin; the third prototype, the first to be fitted with operational equipment including radar, first flew on 7 March 1953. The fourth WT827 was passed to the Aeroplane and Armament Experimental Establishment for trials and the fifth prototype, WT836, made its first flight in July 1954. On 4 July 1954, a prototype Javelin accidentally achieved supersonic speed during a test flight, the pilot having b
Nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or from a combination of fission and fusion reactions. Both bomb types release large quantities of energy from small amounts of matter; the first test of a fission bomb released an amount of energy equal to 20,000 tons of TNT. The first thermonuclear bomb test released energy equal to 10 million tons of TNT. A thermonuclear weapon weighing little more than 2,400 pounds can release energy equal to more than 1.2 million tons of TNT. A nuclear device no larger than traditional bombs can devastate an entire city by blast and radiation. Since they are weapons of mass destruction, the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been used twice in war, both times by the United States against Japan near the end of World War II. On August 6, 1945, the U. S. Army Air Forces detonated a uranium gun-type fission bomb nicknamed "Little Boy" over the Japanese city of Hiroshima.
S. Army Air Forces detonated a plutonium implosion-type fission bomb nicknamed "Fat Man" over the Japanese city of Nagasaki; these bombings caused injuries that resulted in the deaths of 200,000 civilians and military personnel. The ethics of these bombings and their role in Japan's surrender are subjects of debate. Since the atomic bombings of Hiroshima and Nagasaki, nuclear weapons have been detonated over two thousand times for testing and demonstration. Only a few nations are suspected of seeking them; the only countries known to have detonated nuclear weapons—and acknowledge possessing them—are the United States, the Soviet Union, the United Kingdom, China, India and North Korea. Israel is believed to possess nuclear weapons, though, in a policy of deliberate ambiguity, it does not acknowledge having them. Germany, Turkey and the Netherlands are nuclear weapons sharing states. South Africa is the only country to have independently developed and renounced and dismantled its nuclear weapons.
The Treaty on the Non-Proliferation of Nuclear Weapons aims to reduce the spread of nuclear weapons, but its effectiveness has been questioned, political tensions remained high in the 1970s and 1980s. Modernisation of weapons continues to this day. There are two basic types of nuclear weapons: those that derive the majority of their energy from nuclear fission reactions alone, those that use fission reactions to begin nuclear fusion reactions that produce a large amount of the total energy output. All existing nuclear weapons derive some of their explosive energy from nuclear fission reactions. Weapons whose explosive output is from fission reactions are referred to as atomic bombs or atom bombs; this has long been noted as something of a misnomer, as their energy comes from the nucleus of the atom, just as it does with fusion weapons. In fission weapons, a mass of fissile material is forced into supercriticality—allowing an exponential growth of nuclear chain reactions—either by shooting one piece of sub-critical material into another or by compression of a sub-critical sphere or cylinder of fissile material using chemically-fueled explosive lenses.
The latter approach, the "implosion" method, is more sophisticated than the former. A major challenge in all nuclear weapon designs is to ensure that a significant fraction of the fuel is consumed before the weapon destroys itself; the amount of energy released by fission bombs can range from the equivalent of just under a ton to upwards of 500,000 tons of TNT. All fission reactions generate the remains of the split atomic nuclei. Many fission products are either radioactive or moderately radioactive, as such, they are a serious form of radioactive contamination. Fission products are the principal radioactive component of nuclear fallout. Another source of radioactivity is the burst of free neutrons produced by the weapon; when they collide with other nuclei in surrounding material, the neutrons transmute those nuclei into other isotopes, altering their stability and making them radioactive. The most used fissile materials for nuclear weapons applications have been uranium-235 and plutonium-239.
Less used has been uranium-233. Neptunium-237 and some isotopes of americium may be usable for nuclear explosives as well, but it is not clear that this has been implemented, their plausible use in nuclear weapons is a matter of dispute; the other basic type of nuclear weapon produces a large proportion of its energy in nuclear fusion reactions. Such fusion weapons are referred to as thermonuclear weapons or more colloquially as hydrogen bombs, as they rely on fusion reactions between isotopes of hydrogen. All such weapons derive a significant portion of their energy from fission reactions used to "trigger" fusion reactions, fusion reactions can themselves trigger additional fission reactions. Only six countries—United States, United Kingdom, China and India—have conducted thermonuclear weapon tests. North Korea claims to have tested a fusion weapon as of January 2016. Thermonuclear weapons a
Rotterdam
Rotterdam is the second-largest city and a municipality of the Netherlands. It is located in the province of South Holland, at the mouth of the Nieuwe Maas channel leading into the Rhine–Meuse–Scheldt delta at the North Sea, its history goes back to 1270, when a dam was constructed in the Rotte, after which people settled around it for safety. In 1340, Rotterdam was granted city rights by the Count of Holland. A major logistic and economic centre, Rotterdam is Europe's largest port, it has a population of 633,471. Rotterdam is known for its Erasmus University, its riverside setting, lively cultural life and maritime heritage; the near-complete destruction of the city centre in the World War II Rotterdam Blitz has resulted in a varied architectural landscape, including sky-scrapers designed by renowned architects such as Rem Koolhaas, Piet Blom and Ben van Berkel. The Rhine and Scheldt give waterway access into the heart of Western Europe, including the industrialized Ruhr; the extensive distribution system including rail and waterways have earned Rotterdam the nicknames "Gateway to Europe" and "Gateway to the World".
The settlement at the lower end of the fen stream Rotte dates from at least 900 CE. Around 1150, large floods in the area ended development, leading to the construction of protective dikes and dams, including Schielands Hoge Zeedijk along the northern banks of the present-day Nieuwe Maas. A dam on the Rotte was located at the present-day Hoogstraat. On 7 July 1340, Count Willem IV of Holland granted city rights to Rotterdam, whose population was only a few thousand. Around the year 1350, a shipping canal, the Rotterdamse Schie was completed, which provided Rotterdam access to the larger towns in the north, allowing it to become a local trans-shipment centre between the Netherlands and Germany, to urbanize; the port of Rotterdam grew but into a port of importance, becoming the seat of one of the six "chambers" of the Vereenigde Oostindische Compagnie, the Dutch East India Company. The greatest spurt of growth, both in port activity and population, followed the completion of the Nieuwe Waterweg in 1872.
The city and harbor started to expand on the south bank of the river. The Witte Huis or White House skyscraper, inspired by American office buildings and built in 1898 in the French Château-style, is evidence of Rotterdam's rapid growth and success; when completed, it was the tallest office building in Europe, with a height of 45 m. During World War I the city was the world's largest spy centre because of Dutch neutrality and its strategic location in between Great-Britain and German-occupied Belgium. Many spies who were arrested and executed in Britain were led by German secret agents operating from Rotterdam. MI6 had its main European office on de Boompjes. From there the British occupied Belgium. During World War I, an average of 25,000 Belgian refugees lived in the city, as well as hundreds of German deserters and escaped Allied prisoners of war. During World War II, the German army invaded the Netherlands on 10 May 1940. Adolf Hitler had hoped to conquer the country in just one day, but his forces met unexpectedly fierce resistance.
The Dutch army was forced to capitulate on 15 May 1940, following the bombing of Rotterdam on 14 May and the threat of bombing of other Dutch cities. The heart of Rotterdam was completely destroyed by the Luftwaffe; some 80,000 civilians were made homeless and 900 were killed. The City Hall survived the bombing. Ossip Zadkine attempted to capture the event with his statue De Verwoeste Stad; the statue stands near the Leuvehaven, not far from the Erasmusbrug in the centre of the city, on the north shore of the river Nieuwe Maas. Rotterdam was rebuilt from the 1950s through to the 1970s, it remained quite windy and open until the city councils from the 1980s on began developing an active architectural policy. Daring and new styles of apartments, office buildings and recreation facilities resulted in a more'livable' city centre with a new skyline. In the 1990s, the Kop van Zuid was built on the south bank of the river as a new business centre. Rotterdam was voted 2015 European City of the Year by the Academy of Urbanism.
A Guardian profile of Rem Koolhaas begins "If you put the last 50 years of architecture in a blender, spat it out in building-sized chunks across the skyline, you would end up with something that looked a bit like Rotterdam."'Rotterdam' is divided into a northern and a southern part by the river Nieuwe Maas, connected by: the Beneluxtunnel. The former railway lift bridge De Hef is preserved as a monument in lifted position between the Noordereiland and the south of Rotterdam; the city centre is located on the northern bank of the Nieuwe Maas, although recent urban development has extended the centre to parts of southern Rotterdam known as De Kop van Zuid. From its inland core, Rotterdam reaches the North Sea by a swathe of predominantly harbour area. Built behind di
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This article incorporates public domain material from the Air Force Historical Research Agency website http://www.afhra.af.mil/.
