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Arlington Hall Station
Arlington Hall (also called Arlington Hall Station) is a historic building in Arlington, Virginia. Originally it was a girls' school and later the headquarters of the United States Army's Signal Intelligence Service (SIS) cryptography operations during World War II. The site houses the George P. Shultz National Foreign Affairs Training Center and the Army National Guard's Herbert R. Temple Jr. Readiness Center. It is located on Arlington Boulevard (U.S. Route 50) between S. Glebe Road ( State Route 120) and S. George Mason Drive. History Arlington Hall was founded in 1927 as a private post-secondary women's educational institution, which by 1941, was on a campus and was called the Arlington Hall Junior College for Women. The school had financial problems in the 1930s and eventually became a non-profit institution in 1940. On June 10, 1942, the U.S. Army took possession of the facility under the War Powers Act for use by its Signals Intelligence Service. During World War ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Bomb
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear explosion. Both bomb types release large quantities of energy from relatively small amounts of matter. Nuclear bombs have had yields between 10 tons (the W54) and 50 megatons for the Tsar Bomba (see TNT equivalent). Yields in the low kilotons can devastate cities. A thermonuclear weapon weighing as little as can release energy equal to more than 1.2 megatons of TNT (5.0 PJ). Apart from the blast, effects of nuclear weapons include firestorms, extreme heat and ionizing radiation, radioactive nuclear fallout, an electromagnetic pulse, and a radar blackout. The first nuclear weapons were developed by the Allied Manhattan Project during World War II. Their production continues to require a large scientific and industrial complex, primari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhattan Project
The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the project was directed by Major General Leslie Groves of the United States Army Corps of Engineers, U.S. Army Corps of Engineers. Nuclear physicist J. Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the bombs. The Army program was designated the Manhattan District, as its first headquarters were in Manhattan; the name gradually superseded the official codename, Development of Substitute Materials, for the entire project. The project absorbed its earlier British counterpart, Tube Alloys, and subsumed the program from the American civilian Office of Scientific Research and Development. The Manhattan Project employed nearly 130,000 people at its peak and cost nearly US$2 billion (equivalent to about $ b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Lab
The Radiation Laboratory, commonly called the Rad Lab, was a microwave and radar research laboratory located at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts. It was first created in October 1940 and operated until 31 December 1945 when its functions were dispersed to industry, other departments within MIT, and in 1951, the newly formed MIT Lincoln Laboratory. The use of microwaves for various radio and radar uses was highly desired before the war, but existing microwave devices like the klystron were far too low powered to be useful. Alfred Lee Loomis, a millionaire and physicist who headed his own private laboratory, organized the Microwave Committee to consider these devices and look for improvements. In early 1940, Winston Churchill organized what became the Tizard Mission to introduce U.S. researchers to several new technologies the UK had been developing. Among these was the cavity magnetron, a leap forward in the creation of microwaves tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Massachusetts Institute Of Technology
The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of modern technology and science. In response to the increasing Technological and industrial history of the United States, industrialization of the United States, William Barton Rogers organized a school in Boston to create "useful knowledge." Initially funded by a land-grant universities, federal land grant, the institute adopted a Polytechnic, polytechnic model that stressed laboratory instruction in applied science and engineering. MIT moved from Boston to Cambridge in 1916 and grew rapidly through collaboration with private industry, military branches, and new federal basic research agencies, the formation of which was influenced by MIT faculty like Vannevar Bush. In the late twentieth century, MIT became a leading center for research in compu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track aircraft, ships, spacecraft, guided missiles, motor vehicles, map weather formations, and terrain. The term ''RADAR'' was coined in 1940 by the United States Navy as an acronym for "radio detection and ranging". The term ''radar'' has since entered English and other languages as an anacronym, a common noun, losing all capitalization. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwave 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second World War
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frank Rowlett
Frank Byron Rowlett (May 2, 1908 – June 29, 1998) was an American cryptologist. Life and career Rowlett was born in Rose Hill, Lee County, Virginia and attended Emory & Henry College in Emory, Virginia. In 1929 he received a bachelor's degree in mathematics and chemistry. He was hired by William Friedman as a "junior cryptanalyst" for the Signals Intelligence Service (SIS) on April Fools' Day 1930; shortly after, he was followed into SIS by Abraham Sinkov and Solomon Kullback. During the 1930s, after a lengthy period of training, Rowlett and his colleagues compiled codes and ciphers for use by the U.S. Army and began solving a number of foreign, notably Japanese, systems. In the mid-1930s, they solved the first Japanese machine for encipherment of diplomatic communications, known to the Americans as RED. In 1939–40, Rowlett led the SIS effort that solved a more sophisticated Japanese diplomatic machine cipher, codenamed PURPLE by the U.S. Once, when asked what his great ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solomon Kullback
Solomon Kullback (April 3, 1907August 5, 1994) was an American cryptanalyst and mathematician, who was one of the first three employees hired by William F. Friedman at the US Army's Signal Intelligence Service (SIS) in the 1930s, along with Frank Rowlett and Abraham Sinkov. He went on to a long and distinguished career at SIS and its eventual successor, the National Security Agency (NSA). Kullback was the Chief Scientist at the NSA until his retirement in 1962, whereupon he took a position at the George Washington University. The Kullback–Leibler divergence is named after Kullback and Richard Leibler. Life and career Kullback was born to Jewish parents in Brooklyn, New York. His father Nathan had been born in Vilna, Russian Empire, (now Vilnius, Lithuania) and had immigrated to the US as a young man circa 1905, and became a naturalized American in 1911. Kullback attended Boys High School in Brooklyn. He then went to City College of New York, graduating with a BA in 1927 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japanese Army And Diplomatic Codes
Japanese army and diplomatic codes. This article is on Japanese army and diplomatic ciphers and codes used up to and during World War II, to supplement the article on Japanese naval codes. The diplomatic codes were significant militarily, particularly those from diplomats in Germany. Japanese army (IJA) and diplomatic codes were studied at Arlington Hall (US), Bletchley Park (UK), Central Bureau or CBB (Australian, US; in Melbourne, then Brisbane), the FECB (British Far East Combined Bureau) at Hong Kong, Singapore, Kilindi then Colombo and the British Wireless Experimental Centre in Delhi. Japanese Army codes and ciphers Arlington Hall had initially delayed study of the Army codes until 1942 because of the "high payoff" from diplomatic codes, but were not successful until 1943. Then, with success on Army codes in April, the increasing workload was put under Solomon Kullback in branch B-II in September. Other mainly diplomatic work was put under Frank Rowlett in B-III. Branch B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purple (cipher Machine)
The "System 97 Typewriter for European Characters" (九七式欧文印字機 ''kyūnana-shiki ōbun injiki'') or "Type B Cipher Machine", codenamed Purple by the United States, was an encryption machine used by the Japanese Foreign Office from February 1939 to the end of World War II. The machine was an electromechanical device that used stepping-switches to encrypt the most sensitive diplomatic traffic. All messages were written in the 26-letter English alphabet, which was commonly used for telegraphy. Any Japanese text had to be transliterated or coded. The 26-letters were separated using a plug board into two groups, of six and twenty letters respectively. The letters in the sixes group were scrambled using a 6 × 25 substitution table, while letters in the twenties group were more thoroughly scrambled using three successive 20 × 25 substitution tables. The cipher codenamed "Purple" replaced the Type A Red machine previously used by the Japanese Foreign Office. The si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
