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September 2

2010-04-29T20:37:04Z

64.22.228.134:

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==Events==
*[[44 BC]] – [[Pharaoh]] [[Cleopatra VII]] of [[Egypt]] declares her son co-ruler as Ptolemy XV [[Caesarion]].
* 44 BC – The first of [[Cicero]]’s [[Philippic]]s (oratorical attacks) on [[Mark Antony]]. He will make 14 of them over the next several months.
*[[31 BC]] – [[Final War of the Roman Republic]]: [[Battle of Actium]] – off the western coast of [[Greece]], forces of [[Augustus|Octavian]] defeat troops under [[Mark Antony]] and [[Cleopatra VII|Cleopatra]].
*[[1649]] – The [[Italy|Italian]] city of [[Castro (city)|Castro]] is completely destroyed by the forces of [[Pope Innocent X]], ending the [[Wars of Castro]].
*[[1666]] – The [[Great Fire of London]] breaks out and burns for three days, destroying 10,000 buildings including [[St Paul's Cathedral]].
*[[1752]] – [[Great Britain]] adopts the [[Gregorian calendar]], nearly two centuries later than most of [[Western Europe]].
*[[1789]] – The [[United States Department of the Treasury]] is founded.
*[[1792]] – During what became known as the [[September Massacres]] of the [[French Revolution]], rampaging mobs slaughter three [[Roman Catholic Church]] [[bishop]]s, more than two hundred [[priest]]s, and prisoners believed to be royalist sympathizers.
*[[1807]] – The [[Royal Navy]] [[Battle of Copenhagen (1807)|bombards Copenhagen]] with fire bombs and phosphorus rockets to prevent [[Denmark]] from surrendering its fleet to [[Napoleon I of France|Napoleon]].
*[[1833]] – [[Oberlin College]] is founded by John Shipherd and Philo P. Stewart.
*[[1856]] – [[Tianjing Incident]] in [[Nanjing]], China.
*[[1859]] – A [[Aurora (astronomy)#Auroral events of historical significance|solar]] super storm affects [[electrical telegraph]] service.
*[[1862]] – [[American Civil War]]: [[President of the United States|President]] [[Abraham Lincoln]] reluctantly restores [[United States|Union]] [[General officer|General]] [[George B. McClellan]] to full command after General [[John Pope (military officer)|John Pope]]'s disastrous defeat at the [[Second Battle of Bull Run]].
*[[1864]] – American Civil War: Union forces enter [[Atlanta|Atlanta, Georgia]] a day after the [[Confederate States of America|Confederate]] defenders flee the city.
*[[1867]] – Mutsuhito, [[Emperor Meiji]] of [[Japan]], marries Masako Ichijō. The [[Queen consort|Empress consort]] is thereafter known as ''Lady Haruko''. Since her death in 1914, she is called by the posthumous name [[Empress Shōken]].
*[[1870]] – [[Franco-Prussian War]]: [[Battle of Sedan]] – [[Prussia]]n forces take [[Napoleon III of France]] and 100,000 of his soldiers prisoner.
*[[1885]] – [[Rock Springs massacre]]: In [[Rock Springs, Wyoming]], 150 white miners, who are struggling to unionize so they could strike for better wages and work conditions, attack their [[Overseas Chinese|Chinese]] fellow workers, killing 28, wounding 15, and forcing several hundred more out of town.
*[[1898]] – [[Battle of Omdurman]] – [[United Kingdom|British]] and [[Egypt]]ian troops defeat [[Sudan]]ese [[tribe]]smen and establish British dominance in Sudan.
*[[1901]] – [[Vice President of the United States]] [[Theodore Roosevelt]] utters the famous phrase, "Speak softly and carry a [[Big Stick Ideology|big stick]]" at the [[Minnesota State Fair]].
*[[1925]] – The [[United States|U.S.]] [[Zeppelin]] the {{USS|Shenandoah|ZR-1|6}} crashes, killing 14.
*[[1935]] – [[Labor Day Hurricane of 1935]]: a large [[tropical cyclone|hurricane]] hits the [[Florida Keys]] killing 423.
*[[1939]] – [[World War II]]: Following the start of the invasion of [[Second Polish Republic|Poland]] the previous day, the [[Free City of Danzig]] (now [[Gdańsk]], [[Poland]]) is annexed by [[Nazi Germany]].
*[[1945]] – World War II: Combat ends in the [[Pacific War|Pacific Theater]]: the [[Japanese Instrument of Surrender (1945)|Instrument of Surrender]] of [[Imperial Japan|Japan]] is signed by [[Minister for Foreign Affairs (Japan)|Japanese Foreign Minister]] [[Mamoru Shigemitsu]] and accepted aboard the battleship {{USS|Missouri|BB-63|6}} in [[Tokyo Bay]].
* 1945 – [[Vietnam]] declares its independence, forming the [[North Vietnam|Democratic Republic of Vietnam]].
*[[1946]] – Interim Government of India is formed with [[Jawaharlal Nehru]] as Vice President.
*[[1958]] – [[United States Air Force]] [[C-130 Hercules|C-130A-II]] is shot down by fighters over [[Yerevan|Yerevan, Armenia]] when it strays into [[Soviet Union|Soviet]] airspace while conducting a [[Signals intelligence|sigint]] mission. All crew members are killed.
*[[1960]] – The first election of the [[Parliament of the Central Tibetan Administration]], in [[history of Tibet]]. The Tibetan community observes this date as the '''Democracy Day'''.
*[[1963]] – ''[[CBS Evening News]]'' becomes [[United States|U.S.]] network [[television]]'s first half-hour weeknight [[news]] broadcast, when the show is lengthened from 15 to 30 minutes.
*[[1967]] – The [[Principality of Sealand]] is established, ruled by Prince [[Paddy Roy Bates]].
*[[1970]] – [[NASA]] announces the [[Canceled Apollo missions|cancellation]] of two [[Apollo program|Apollo]] missions to the [[Moon]], [[Apollo 15]] (the designation is re-used by a later mission), and [[Canceled Apollo missions#Apollos 18–20|Apollo 19]].
*[[1990]] – [[Transnistria]] is unilaterally proclaimed a [[Soviet Union|Soviet]] republic; the [[Presidium of the Supreme Soviet|Soviet president]] [[Mikhail Gorbachev]] declares the decision null and void.
*[[1991]] – The [[United States]] recognizes the independence of the [[Baltic states]]: [[Estonia]], [[Latvia]], and [[Lithuania]].
*[[1992]] – An [[1992 Nicaragua earthquake|earthquake in Nicaragua]] kills at least 116 people
*[[1996]] – A peace agreement is signed between the [[Politics of the Philippines|Government of the Republic of the Philippines]] and the [[Moro National Liberation Front]] in [[Malacañang Palace]].
*[[1998]] – [[Swissair Flight 111]] crashes near [[Peggys Cove, Nova Scotia]]. All 229 people on board are killed.
* 1998 – The [[United Nations|UN]]'s [[International Criminal Tribunal for Rwanda]] finds [[Jean Paul Akayesu]], the former [[mayor]] of a small town in [[Rwanda]], guilty of nine counts of [[genocide]].

==Births==
*[[1661]] – [[Georg Böhm]], German organist (d. 1733)
*[[1675]] – [[William Somervile]], English poet (d. 1742)
*[[1753]] – [[Marie Josephine Louise of Savoy]], queen of France (d. 1810)
*[[1778]] – [[Louis Bonaparte]], King of Holland (d. 1846)
*[[1805]] – [[Esteban Echeverría]], Argentine writer (d. 1851)
*[[1810]] – [[William Seymour Tyler]], American educator and historian (d. 1897)
*[[1830]] – [[William P. Frye]], American politician (d. 1911)
*[[1838]] – [[Liliuokalani of Hawaii]], Queen of Hawaii (d. 1917)
*[[1847]] – [[Roger Wolcott (Massachusetts)|Roger Wolcott]], 39th [[Governor of Massachusetts]] (d. 1900)
*[[1850]] – [[Albert Spalding]], baseball player and sporting goods manufacturer (d. 1915)
* 1850 – [[Woldemar Voigt]], German physicist (d. 1919)
*[[1852]] – [[Paul Bourget]], French novelist and critic (d. 1935)
*[[1853]] – [[Wilhelm Ostwald]], Baltic German chemist, [[Nobel Prize in Chemistry|Nobel laureate]] (d. 1932)
*[[1854]] – [[Hans Jæger]], Norwegian writer and political activist (d. 1910)
*[[1857]] – [[Thomas Groube]], Australian cricketer (d. 1927)
*[[1862]] – [[Franjo Krežma]], Croatian violinist (d. 1881)
*[[1866]] – [[Charles Vintcent]], South African cricketer (d. 1943)
*[[1877]] – [[Frederick Soddy]], British chemist, [[Nobel Prize in Chemistry|Nobel laureate]] (d. 1956)
*[[1878]] – [[Ion Dragoumis]], Greek diplomat, writer and revolutionary (d. 1920)
* 1878 – [[Werner von Blomberg]], German field marshal (d. 1946)
*[[1879]] – [[An Jung-geun]], Korean assassin of [[Ito Hirobumi]] (d. 1910)
*[[1883]] – [[Archduchess Elisabeth Marie of Austria]], "The Red Archduchess" (d. 1963)
*[[1884]] – [[Frank Laubach|Dr. Frank C. Laubach]], Christian missionary (d. 1970)
*[[1894]] – [[Joseph Roth]], Austrian novelist (d. 1939)
*[[1901]] – [[Andreas Embirikos]], Greek surrealist poet (d. 1975)
* 1901 – [[Adolph Rupp]], American college basketball coach (d. 1977)
*[[1911]] – [[Romare Bearden]], African American painter (d. 1988)
*[[1912]] – [[Ernest Bromley (cricketer)|Ernest Bromley]], Australian cricketer (d. 1967)
*[[1913]] – [[Bill Shankly]], Scotish Football Manager (d. 1981)
* 1913 – [[Israel Gelfand]], Russian mathematician (d. 2009)
*[[1914]] – [[Tom Glazer]], American folk singer and songwriter (d. 2003)
*[[1915]] – [[Meinhardt Raabe]], actor, notable as Munchkin Coroner on [[The Wizard of Oz (1939 film)|The Wizard of Oz]]
* 1915 – [[Benjamin Aaron]], American labor law expert (d. 2007)
*[[1917]] – [[Cleveland Amory]], American author (d. 1998)
* 1917 – [[Laurindo Almeida]], Brazilian guitarist (d. 1995)
*[[1923]] – [[Rene Thom]], French mathematician (d. 2002)
*[[1924]] – [[Daniel arap Moi]], [[President of Kenya]]
*[[1925]] – [[Hugo Montenegro]], American composer and bandleader (d. 1981)
*[[1928]] – [[Horace Silver]], American jazz pianist and composer
*[[1929]] – [[Hal Ashby]], American film director (d. 1988)
*[[1931]] – [[Clifford Jordan]], American jazz saxophonist (d. 1993)
*[[1933]] – [[Victor Spinetti]], Welsh actor
*[[1934]] – [[Grady Nutt]], American humorist
*[[1935]] – [[D. Wayne Lukas]], American horse trainer
*[[1936]] – [[Andrew Grove]], American computer chip manufacturer
*[[1937]] – [[Peter Ueberroth]], American sport executive
* 1937 – [[Derek Fowlds]], British actor
* 1937 – [[Len Carlson]], Canadian voice actor (d. 2006)
*[[1938]] – [[Mary Jo Catlett]], American actress
* 1938 – [[Clarence Felder]], American actor
* 1938 – [[Giuliano Gemma]], Italian actor
*[[1939]] – [[Sam Gooden]], American singer ([[The Impressions (American band)|The Impressions]])
*[[1940]] – [[Jimmy Clanton]], American singer
*[[1941]] – [[David Bale]], South African–born activist (d. 2003)
* 1941 – [[Graeme Langlands]], Australian rugby league footballer
* 1941 – [[John Thompson, Jr.]], American college basketball coach
*[[1943]] – [[Rosalind Ashford]], American singer ([[Martha and the Vandellas]])
* 1943 – [[Glen Sather]], Canadian ice hockey player and executive
* 1943 – [[Joe Simon (musician)|Joe Simon]], American singer
*[[1946]] – [[Billy Preston]], American musician (d. 2006)
* 1946 – [[Dan White]], American assassin (d. 1985)
* 1946 – [[Luis Avalos]], Cuban actor
* 1946 – [[Walt Simonson]], American comic book artist & writer
*[[1947]] – [[Richard Coughlan]], English drummer and percussionist ([[Caravan (band)|Caravan]])
*[[1948]] – [[Terry Bradshaw]], American football player
* 1948 – [[Christa McAuliffe]], American schoolteacher and astronaut (d. 1986)
* 1948 – [[Nate Archibald]], American basketball player
*[[1950]] – [[Rosanna DeSoto]], American actress
* 1950 – [[Michael Rother]], German musician ([[Neu!]], [[Kraftwerk]], [[Harmonia (band)|Harmonia]], [[Cluster (band)|Cluster]])
* 1950 – [[Yuen Wah]], Chinese actor and stuntman
*[[1951]] – [[Jim DeMint]], American politician
* 1951 – [[Mark Harmon]], American actor
* 1951 – [[Michael Gray (actor)|Michael Gray]], American actor
* 1951 – [[Jon Feltheimer]], American film executive
*[[1952]] – [[Jimmy Connors]], American tennis player
*[[1953]] – [[Ahmad Shah Massoud]], Afghan commander (d. 2001)
* 1953 – [[John Zorn]], American musician
*[[1956]] – [[Mario Tremblay]], Canadian hockey player and coach
* 1956 – [[Angelo Fusco]], Provisional Irish Republican Army member
*[[1957]] – [[Tony Alva]], American skateboarder
*[[1958]] – [[Olivier Grouillard]], French racing driver
*[[1959]] – [[Guy Laliberté]], founder of [[Cirque du Soleil]]
*[[1960]] – [[Kristin Halvorsen]], Norwegian politician
* 1960 – [[Rex Hudler]], baseball player
* 1960 – [[Eric Dickerson]], American football player
* 1960 – [[John S. Hall]], American poet and spoken-word artist
* 1960 – [[Hideo Yoshizawa]], General Manager at Namco Bandai
*[[1961]] – [[Carlos Valderrama (soccer player)|Carlos Valderrama]], Colombian footballer
*[[1962]] – [[Prachya Pinkaew]], Thai film director
* 1962 – [[Eugenio Derbez]], Mexican comedian and actor
* 1962 – [[Jon Berkeley]], author and illustrator
*[[1963]] – [[Sam Mitchell]], former basketball player and coach
*[[1964]] – [[Keanu Reeves]], Canadian actor
*[[1964]] – [[Michael Zalewski]], American Technology Specialist
*[[1965]] – [[Lennox Lewis]], British-born boxer
* 1965 – [[Partho Sen-Gupta]], Indian filmmaker
*[[1966]] – [[Salma Hayek]], Mexican actress
* 1966 – [[Dino Cazares]], American musician
* 1966 – [[Olivier Panis]], French race car driver
* 1966 – [[Tuc Watkins]], American actor
*[[1967]] – [[Andreas Möller]], German footballer
*[[1968]] – [[Cynthia Watros]], American actress
* 1968 – [[Kristen Cloke]], American actress
*[[1969]] – [[Cedric "K-Ci" Hailey]], American singer
* 1969 – [[Chris Kuzneski]], American bestselling author
* 1969 – [[Stéphane Matteau]], French Canadian ice hockey player
* 1969 – [[Stephen Peall]], Zimbabwean cricketer
*[[1971]] – [[Kjetil André Aamodt]], Norwegian skier
* 1971 – [[Pawan Kalyan]], Indian actor
*[[1971]] – [[César Sánchez]], Spanish footballer
* 1971 – [[Tommy Maddox]], American football player
* 1971 – [[Tom Steels]], Belgian cyclist
*[[1972]] – [[Matthew Dunn]], Australian swimmer
* 1972 – [[Robert Coles (golfer)|Robert Coles]], professional golfer
*[[1973]] – [[Katt Williams]], American comedian,actor,and rapper
* 1973 – [[Jason Blake (ice hockey player)|Jason Blake]], American hockey player
* 1973 – [[Indika de Saram]], Sri Lankan cricketer
*[[1974]] – [[Steven Johnson (motor racing)|Steven Johnson]], Australian racing driver
*[[1975]] – [[MC Chris]], American rapper
*[[1976]] – [[Phil Lipscomb]], American musician ([[Taproot (band)|Taproot]])
* 1976 – [[Erin Hershey Presley|Erin Hershey]], American actress
* 1976 – [[Aziz Zakari]], Ghanaian athlete specializing in the 100 metres
*[[1977]] – [[Ramiro Muñoz]], Colombian musician
* 1977 – [[Frédéric Kanouté]], Malian footballer
*[[1979]] – [[Tomer Ben Yosef]], Israeli footballer
* 1979 – [[Alex Chu]], Canadian-born Korean singer
* 1979 – [[Ron Ng]], Hong Kong actor
* 1979 – [[Brian Westbrook]], American football player
*[[1980]] – [[Dany Sabourin]], French Canadian Goaltender in the National Hockey League
* 1980 – [[Hiroki Yoshimoto]], Japanese racing driver
*[[1981]] – [[Chris Tremlett]], English cricketer
* 1981 – [[Bracha van Doesburgh]], Dutch actress
* 1981 – [[Fariborz Kamkari]], Iranian film director/producer
*[[1982]] – [[Joey Barton]], English footballer
* 1982 – [[Mandy Cho]], Hong Kong actress
* 1982 – [[Jason Hammel (baseball)|Jason Hammel]], American baseball player
*[[1983]] – [[Mark Foster (rugby player)|Mark Foster]], English rugby player
* 1983 – [[Aimee Osbourne]], English singer, actress and columnist
*[[1984]] – [[Danson Tang]], Taiwanese actor, model, and singer
* 1984 – [[Jack Peñate]], English singer
* 1984 – [[Udita Goswami]], Indian model and actress
*[[1986]] – [[Kyle Hines]], American basketball player
*[[1987]] – [[Scott Moir]], Canadian ice dancer
*[[1988]] – [[Ishant Sharma]], Indian Cricketer
*[[1989]] – [[Alexandre Pato]], Brazilian footballer
* 1989 – [[Ishmeet Singh Sodhi]], Indian playback singer (d. 2008)
*[[1990]] – [[Marcus Ericsson]], Swedish racing driver


==Deaths==
*[[490 BC]] – [[Pheidippides]], Greek hero
* [[421]] – [[Constantius III]], [[Roman Emperor]]
*[[1031]] – [[Emeric of Hungary (saint)|Saint Emeric of Hungary]]
*[[1274]] – [[Prince Munetaka]], Japanese shogun (b. 1242)
*[[1397]] – [[Francesco Landini]], Italian composer
*[[1540]] – [[Dawit II of Ethiopia|Lebna Dengel]], [[Emperor of Ethiopia]] (b. 1501)
*[[1680]] – [[Per Brahe (the younger)|Per Brahe]], Swedish soldier and statesman (b. 1602)
*[[1688]] – [[Sir Robert Viner, 1st Baronet|Robert Viner]], Lord Mayor of London (b. 1631)
*[[1690]] – [[Philipp Wilhelm, Elector Palatine]] (b. 1615)
*[[1764]] – [[Nathaniel Bliss]], English [[Astronomer Royal]] (b. 1700)
*[[1765]] – [[Henry Bouquet]], Swiss-born British army officer (b. 1719)
*[[1768]] – [[Antoine Deparcieux]], French mathematician (b. 1703)
*[[1790]] – [[Johann Nikolaus von Hontheim]], German historian and theologian (b. 1701)
*[[1813]] – [[Jean Victor Marie Moreau]], French general (mortally wounded in battle) (b. 1763)
*[[1820]] – [[Jiaqing]], [[Emperor of China]] (b. 1760)
*[[1832]] – [[Franz Xaver, Baron Von Zach]], Austrian astronomer (b. 1754)
*[[1834]] – [[Thomas Telford]], Scottish civil engineer (b. 1757)
*[[1865]] – [[William Rowan Hamilton]], Irish mathematician (b. 1805)
*[[1872]] – [[Nicolai Grundtvig]], Danish writer and philosopher (b. 1783)
*[[1877]] – [[Constantine Kanaris]], Greek admiral, freedom fighter and politician (b. 1793)
*[[1896]] – [[Nat Thomson]], Australian cricketer (b. 1839)
*[[1898]] – [[Wilford Woodruff]], fourth president of [[The Church of Jesus Christ of Latter-day Saints]] (b. 1807)
*[[1910]] – [[Henri Rousseau]], French painter (b. 1844)
*[[1921]] – [[Henry Austin Dobson]], English poet (b. 1840)
* 1921 – [[Anthony Francis Lucas]] Croatian-born oil pioneer (b. 1855)
*[[1934]] – [[Alcide Nunez]], American musician (b. 1884)
* 1934 – [[Russ Columbo]], American singer, violinist and actor (b. 1908)
* 1934 – [[James Allan (rugby)|James Allan]], New Zealand rugby union player, All Black (b. 1860)
*[[1937]] – [[Pierre de Coubertin]], French founder of the modern Olympic Games (b. 1863)
*[[1941]] – [[Lloyd Seay]], American stock car driver (b. 1919)
*[[1942]] – [[Tom Williams (Irish Republican)|Tom Williams]], Irish republican (b. 1924)
*[[1944]] – [[Bella Rosenfeld]], subject of many of [[Marc Chagall]] paintings (b. 1895)
*[[1948]] – [[Sylvanus Morley]], American archaeologist and spy (b. 1883)
*[[1953]] – [[Jonathan Mayhew Wainwright IV]], U.S. general (b. 1883)
*[[1962]] – [[William Wilkerson]], Founder of the [[Hollywood Reporter]], The [[Flamingo Hotel]] in Las Vegas and nightclubs such as [[Ciro's]] (b. 1890)
*[[1964]] – [[Glenn Albert Black]], American archaeologist (b. 1900)
* 1964 – [[Francisco Craveiro Lopes]], 13th [[President of Portugal]] (b. 1894)
* 1964 – [[Alvin York]], American soldier (b. 1887)
*[[1965]] – [[Johannes Bobrowski]], German writer (b. 1917)
*[[1969]] – [[Ho Chi Minh]], [[President of Vietnam]] (b. 1890)
*[[1973]] – [[Carl Dudley]], American film director (b. 1910)
* 1973 – [[J. R. R. Tolkien]], British writer (b. 1892)
*[[1976]] – [[Stanisław Grochowiak]], Polish writer (b. 1934)
*[[1978]] – [[Fred G. Meyer]], Founder Fred Meyer Inc. (b. 1886)
*[[1979]] – [[Otto P. Weyland]], American military figure (b. 1903)
*[[1984]] – [[Manos Katrakis]], Greek actor (b. 1908)
*[[1985]] – [[Abe Lenstra]], Dutch footballer (b. 1920)
* 1985 – [[Jay Youngblood]], American professional wrestler
*[[1991]] – [[Alfonso García Robles]], Mexican diplomat and politician, recipient of the [[Nobel Peace Prize]] (b. 1911)
*[[1992]] – [[Barbara McClintock]], American geneticist, [[Nobel Prize in Physiology or Medicine|Nobel laureate]] (b. 1902)
*[[1994]] – [[Roy Castle]], British entertainer (b. 1932)
*[[1996]] – [[Paddy Clift]], Leicestershire cricketer (b. 1953)
*[[1997]] – [[Rudolph Bing]], Austrian-born opera manager (b. 1902)
* 1997 – [[Viktor Frankl]], Austrian neurologist and psychiatrist (b. 1905)
*[[1998]] – [[Jackie Blanchflower]], Irish footballer (b. 1933)
* 1998 – [[Allen Drury]], American author (b. 1918)
*[[2000]] – [[Elvera Sanchez]], Puerto Rican dancer (b. 1905)
* 2000 – [[Curt Siodmak]], German-born author (b. 1907)
*[[2001]] – [[Christiaan Barnard]], South African heart surgeon (b. 1922)
* 2001 – [[Troy Donahue]], American actor (b. 1936)
*[[2002]] – [[Dick Reynolds]], Australian rules footballer and coach (b. 1915)
*[[2004]] – [[Joan Oró]], Catalan scientist (b. 1923)
* 2004 – [[Eleni Zafeiriou]], Greek actress (b. 1916)
*[[2005]] – [[Bob Denver]], American actor (b. 1935)
*[[2006]] – [[Bob Mathias]], American athlete and congressman (b. 1930)
* 2006 – [[Willi Ninja]], dancer and choreographer (b. 1961)
*[[2007]] – [[Max McNab]], [[National Hockey League]] executive (b. 1924)
* 2007 – [[Franz-Benno Delonge]], German [[German-style board game|game]] designer (b. 1957)
* 2007 – [[Rajae Belmlih]], Moroccan singer (b. 1962)
*[[2008]] – [[Bill Meléndez]], American character animator (b. 1916)
*[[2009]] – [[Y. S. Rajasekhara Reddy]], Chief Minister of Andhra Pradesh, India (b. 1949)


==Holidays and observances==
* Also see [[September 2 (Eastern Orthodox liturgics)]]
*[[Calendar of Saints|RC Saints]] – [[Saint Nonnosus]], [[Agricola of Avignon]], [[Saint Castor of Apt]], [[Antoninus of Pamiers]].
*[[Mauritius]] – [[Ganesh Chaturthi]].
*[[Transnistria]] – ''[[Independence day]]'', note [[Transnistria]] is not an internationally recognized independent state.
*Sedan Day (Sedantag) – traditional national [[Germany|German]] holiday (see [[Sedan, France]]) that commemorates [[Prussia]]'s victory over [[France]] in 1870, making the [[German Empire]] a reality.
*[[Vietnam]] – [[National Day]] (independence from [[Japan]] and [[France]], 1945).
*[[Acepsimas of Hnaita]] and companions
*[[Acoma Pueblo]] – [[Feast day of St Stephen, King and Confessor|Feast Day of San Esteban del Rey]]

==External links==
{{commons}}
*[http://news.bbc.co.uk/onthisday/hi/dates/stories/september/2 BBC: On This Day]
*{{NYT On this day|month=09|day=02}}
*[http://www1.sympatico.ca/cgi-bin/on_this_day?mth=Sep&day=02 On This Day in Canada]
----
{{months}}

{{DEFAULTSORT:September 02}}
[[Category:Days of the year]]
[[Category:September]]

[[af:2 September]]
[[ang:2 Hāliȝmōnaþ]]
[[ar:ملحق:2 سبتمبر]]
[[an:2 de setiembre]]
[[frp:2 septembro]]
[[ast:2 de setiembre]]
[[az:2 sentyabr]]
[[zh-min-nan:9 goe̍h 2 ji̍t]]
[[be:2 верасня]]
[[be-x-old:2 верасьня]]
[[bcl:Septyembre 2]]
[[bs:2. septembar]]
[[br:2 Gwengolo]]
[[bg:2 септември]]
[[ca:2 de setembre]]
[[cv:Авăн, 2]]
[[ceb:Septiyembre 2]]
[[cs:2. září]]
[[co:2 di settembre]]
[[cy:2 Medi]]
[[da:2. september]]
[[de:2. September]]
[[et:2. september]]
[[el:2 Σεπτεμβρίου]]
[[myv:Таштамковонь 2 чи]]
[[es:2 de septiembre]]
[[eo:2-a de septembro]]
[[eu:Irailaren 2]]
[[fa:۲ سپتامبر]]
[[hif:2 September]]
[[fo:2. september]]
[[fr:2 septembre]]
[[fy:2 septimber]]
[[fur:2 di Setembar]]
[[ga:2 Meán Fómhair]]
[[gv:2 Mean Fouyir]]
[[gd:2 an t-Sultain]]
[[gl:2 de setembro]]
[[gan:9月2號]]
[[gu:સપ્ટેમ્બર ૨]]
[[xal:Һаха сарин 2]]
[[ko:9월 2일]]
[[hr:2. rujna]]
[[io:2 di septembro]]
[[bpy:সেপ্টেম্বর ২]]
[[id:2 September]]
[[ia:2 de septembre]]
[[is:2. september]]
[[it:2 settembre]]
[[he:2 בספטמבר]]
[[jv:2 September]]
[[kn:ಸೆಪ್ಟೆಂಬರ್ ೨]]
[[pam:Septiembri 2]]
[[ka:2 სექტემბერი]]
[[csb:2 séwnika]]
[[kk:Қыркүйектің 2]]
[[sw:2 Septemba]]
[[ht:2 septanm]]
[[ku:2'ê rezberê]]
[[la:2 Septembris]]
[[lv:2. septembris]]
[[lb:2. September]]
[[lt:Rugsėjo 2]]
[[li:2 september]]
[[lmo:02 09]]
[[hu:Szeptember 2.]]
[[mk:2 септември]]
[[ml:സെപ്റ്റംബർ 2]]
[[mr:सप्टेंबर २]]
[[arz:2 سبتمبر]]
[[ms:2 September]]
[[nah:Tlachiucnāuhti 2]]
[[nl:2 september]]
[[nds-nl:2 september]]
[[new:सेप्टेम्बर २]]
[[ja:9月2日]]
[[nap:2 'e settembre]]
[[no:2. september]]
[[nn:2. september]]
[[nrm:2 Septembre]]
[[nov:2 de septembre]]
[[oc:2 de setembre]]
[[mhr:2 Идым]]
[[uz:2-sentabr]]
[[pa:੨ ਸਤੰਬਰ]]
[[pag:September 2]]
[[nds:2. September]]
[[pl:2 września]]
[[pnt:2 Σταυρί]]
[[pt:2 de setembro]]
[[ksh:2. Sepptämmber]]
[[ro:2 septembrie]]
[[qu:2 ñiqin tarpuy killapi]]
[[ru:2 сентября]]
[[sah:Балаҕан ыйын 2]]
[[se:Čakčamánu 2.]]
[[sco:2 September]]
[[sq:2 Shtator]]
[[scn:2 di sittèmmiru]]
[[simple:September 2]]
[[sk:2. september]]
[[sl:2. september]]
[[sr:2. септембар]]
[[sh:2.9.]]
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Jehovah's Witnesses

2010-04-14T21:53:30Z

64.22.228.134:

{{pp-move-indef}}
{{Infobox Christian denomination
| name=Jehovah's Witnesses
| image=Watchtower headquarters.jpg
| caption=Watchtower Buildings in Brooklyn, New York
| main_classification=[[Millenarianism|Millenarian]]
| orientation = [[Restorationism (Christian primitivism)|Restorationist]]
| structure = [[Organizational structure of Jehovah's Witnesses|Hierarchical]]
| founder = [[Charles Taze Russell]] (founded [[Bible Student movement]])
| founded_date = 1876: Bible Students founded 1931: Named ''Jehovah's witnesses''
| founded_place = [[Pennsylvania]] and [[New York]], [[United States|USA]]
| parent = [[Bible Student movement]]
| separations = See ''[[Jehovah's Witnesses splinter groups|Jehovah's Witnesses splinter groups]]''
| area = Worldwide
| congregations = 105,298
| members = 7.3 million
| footnotes = Statistics from ''2010 Yearbook of Jehovah's Witnesses''
| website = http://www.watchtower.org
}}
{{clearright}}
'''Jehovah's Witnesses''' is a [[Restorationism (Christian primitivism)|restorationist]],<ref>{{cite journal| author=Stark et al.| year=1997| title=Why Jehovah's Witnesses Grow So Rapidly: A Theoretical Application| journal=Journal of Contemporary Religion| volume=12| issue=2| pages=133–157| doi=10.1080/13537909708580796}}</ref> [[millenarianism|millenarian]]<ref>{{cite book|title=Oxford English Dictionary|quote=Jehovah's Witness: a member of a fundamentalist millenary sect}}</ref> [[Christian]] [[Religious denomination|denomination]].<ref>{{cite web|url=http://www.religioustolerance.org/chr_defn.htm|title=Religious Tolerance.org}}</ref><ref>{{cite web|url=http://www.beliefnet.com/Faiths/Christianity/index.aspx|title=BeliefNet}}</ref><ref>{{cite web|url=http://www.adherents.com/Religions_By_Adherents.html#Christianity|title=Adherents.com}}</ref><ref>{{cite web |url= http://www.bbc.co.uk/religion/religions/witnesses/ataglance/glance.shtml|title= Religion & Ethics Jehovah's Witnesses|quote=Jehovah's Witnesses are members of a Christian-based religious movement.}}</ref><ref>{{cite web|url=http://www.worldalmanacforkids.com/WAKI-ViewArticle.aspx?pin=w-rlg00700&article_id=512&chapter_id=11&chapter_title=Religion&article_title=Adherents_of_All_Religions|title= Major Christian Denominations}}</ref><ref>[http://www.ajwrb.org/jme/jmef.htm Organisational charter, Denomination of Jehovah's Witnesses in Bulgaria, as cited by Donald T. Ridley, Watch Tower Society, in "Jehovah’s Witnesses’ refusal of blood: obedience to scripture and religious conscience", ''Journal of Medical Ethics'', December 1999, footnote 1.]</ref> The religion reports worldwide membership of over 7 million adherents involved in [[evangelism]];<ref>{{cite web|url=http://jw-media.org/aboutjw/article41.htm#membership|title=Jehovah’s Witnesses Official Media Web Site: Our History and Organization - Membership|publisher=Office of Public Information of Jehovah's Witnesses|quote=While other religious groups count their membership by occasional or annual attendance, this figure reflects only those who are actively involved in the public Bible educational work [of Jehovah's Witnesses].}}</ref> they report convention attendance of over 12 million, and annual [[Beliefs and practices of Jehovah's Witnesses#Memorial of Christ's death|Memorial]] attendance of over 18 million.<ref>"“Guided by God’s Spirit”", ''Awake!'', June 2008, page 32, "In 2007, more than 12 million people attended over 3,200 of such conventions!"</ref><ref>[http://www.jw-media.org/aboutjw/article41.htm#membership Statistics at Jehovah's Witnesses official website, 2010.]</ref> They are directed by a [[Governing Body of Jehovah's Witnesses|Governing Body]] of [[Elder (Christianity)#Jehovah.27s Witnesses|elders]] which exercises authority on all doctrinal matters. Witnesses base their beliefs on the [[Bible]], and prefer their own translation, the ''[[New World Translation of the Holy Scriptures]]''.<ref>{{cite book|title=Jehovah's Witnesses Proclaimers of God's Kingdom|publisher=Watchtower Bible and Tract Society|year=1993}}</ref><ref>Alan Rogerson, ''Millions Now Living Will Never Die'', Constable, 1969, page 123.</ref>

The group emerged from the [[Bible Student movement]],<ref>{{cite web|url= http://www.thearda.com/Denoms/D_1107.asp |title=Denominational profile|publisher=The Association of Religion Data Archives (ARDA)}}</ref> founded in the late [[19th century]] by [[Charles Taze Russell]], with the formation of [[Watch Tower Bible and Tract Society of Pennsylvania|Zion's Watch Tower Tract Society]]. Following a schism in the movement, the branch that maintained control of the Society underwent significant organizational changes, bringing its authority structure and methods of evangelism under centralized control.<ref name=orwell3>{{cite book| last = Botting| first = Heather| coauthors = Gary Botting| title = The Orwellian World of Jehovah's Witnesses| publisher = [[University of Toronto Press]]| year = 1984| pages = 60–75| isbn = 0-8020-6545-7}}</ref><ref>{{cite book|last=Franz|first=Raymond|title=In Search of Christian Freedom|publisher=Commentary Press|year=2007|page=190|quote=Rutherford wanted to unify the preaching work and, instead of having each individual give his own opinion ... gradually Rutherford himself began to be the main spokesman for the organization.}} (Franz quoting ''Faith on the March'', 1957, A. H. MacMillan)</ref> The name ''Jehovah's witnesses'', based on [[Book of Isaiah|Isaiah]] 43:10-12, was adopted in 1931.

Since its inception, the Watch Tower Society has taught that the present world order is in its [[end time|last days]]<ref>{{cite book|author=Penton, M. J.|title=Apocalypse Delayed|publisher=University of Toronto Press|edition=2nd|year=1997|page=1}}</ref> and will soon be destroyed at [[Armageddon]]. It has stated that only Jehovah's Witnesses "have any Scriptural hope of surviving the impending end of this doomed system",<ref name=onlyjw>"Remaining Organized for Survival Into the Millennium", The Watchtower, September 1, 1989, page 19, "Only Jehovah's Witnesses, those of the anointed remnant and the 'great crowd,' as a united organization under the protection of the Supreme Organizer, have any Scriptural hope of surviving the impending end of this doomed system dominated by Satan the Devil."</ref> but that God decides who will survive.<ref>"Watchtower 11/1 2008 Page 28 - Our Readers Ask; Do Jehovah's Witnesses Believe That They Are the Only Ones Who Will Be Saved?". Quote:"Like adherents of many religious faiths, Jehovah’s Witnesses hope to be saved. However, they also believe that it is not their job to judge who will be saved. Ultimately, God is the Judge. He decides.—Isaiah 33:22."</ref> Those whom God chooses to save—survivors and [[resurrection|resurrected]] individuals—will have the opportunity to live forever in an earthly [[Paradise#Jehovah's Witnesses|paradise]], ruled by Christ and 144,000 humans raised to [[heaven]]. In the years leading up to 1914, 1925 and 1975, the Watch Tower Society's publications expressed strong expectations of Armageddon or the establishment of Christ's kingdom over the earth occurring in those years.<ref>''The Jehovah's Witnesses and Prophetic Speculation'', Edmond C. Gruss, 1972, ISBN 0-87552-306-4, pages 11, 21.</ref><ref>J. F. Rutherford, ''Millions Now Living Will Never Die'', 1920, page 88, as reproduced by Raymond Franz, ''Crisis of Conscience'', pages 212-214.</ref><ref>{{cite book|title=Life Everlasting in Freedom of the Sons of God|publisher=Watch Tower Society|year=1966|url=http://www.strictlygenteel.co.uk/lifeeverlasting/1966_Life_Everlasting.pdf|pages=29–35}}</ref><ref>[http://web.uni-marburg.de/religionswissenschaft/journal/diskus/wilson.html Bryan R. Wilson, "The Persistence of Sects", ''Diskus'' religious studies journal web edition, Vol.1 No.2, 1993, pp.1-12.]</ref>

Jehovah's Witnesses are best known for their door-to-door preaching, distribution of literature such as ''[[The Watchtower]]'' and ''[[Awake!]]'', and for their refusal of [[military service]] and [[blood transfusion]]s even in life-threatening situations.<ref name=Believe>{{cite book| last = Evans| first = Allan S.| coauthors = Riley E. Moynes, Larry Martinello| title = What man Believes: A study of the World’s Great Faiths| publisher = McGraw-Hill Ryerson| year = 1973| page = 424| isbn = 0-07-077440-4}}</ref><ref name=Vancouver>{{cite web|url=http://www.rickross.com/reference/jw/jw289.html|title=Jehovah's Witnesses case heads to B.C. court|publisher=Vancouver Sun|date=1 April 1, 2007}}</ref><ref name="pulsus.com">{{cite web|url=http://www.pulsus.com/journals/abstract.jsp?HCtype=Consumer&sCurrPg=journal&jnlKy=5&atlKy=6964&isuKy=460&spage=1&isArt=t&|title=Medical emergencies in children of orthodox Jehovah's Witness families: Three recent legal cases, ethical issues and proposals for management|author=J Guicho and, I Mitchell|publisher=Paediatrics & Child Health, Canadian Pediatric Society|month=December | year=2006}}</ref><ref name=BloodlessMedicine>{{cite web|url=http://www.watchtower.org/e/20000108/article_01.htm|title=Bloodless Medicine and Surgery, The Growing Demand|date=January 8, 2000}}</ref> They consider use of the name ''[[Jehovah]]''—one of the common English-language pronunciations of the [[Tetragrammaton]]—vital for proper worship. They reject [[Trinity|Trinitarianism]], immortality of the [[soul]], and [[Hell in Christian beliefs#Jehovah's Witnesses|hellfire]], which they consider to be unscriptural doctrines. They do not observe celebrations such as [[Christmas]],<ref name=Christmas>{{cite web|url=http://www.watchtower.org/e/20001215/article_01.htm |title=Christmas Customs, Are They Christian?|publisher=Watchtower website|year=2008}}</ref><ref name=respect>{{cite web|url=http://www.jw-media.org/usa/20001214.htm|title=For those who don’t celebrate Christmas, respect and good communication are key| publisher=Watchtower Public Information Site|date = December 14, 2000}}</ref> [[Easter]] or [[birthday]]s,<ref>{{cite web |url=http://www.watchtower.org/e/rq/article_11.htm|title=Beliefs and Customs That Displease God|work=Watchtower|year=2006}}</ref> which they believe have [[paganism|pagan]] origins that are not compatible with Christianity. Members commonly refer to their body of beliefs as "the Truth", and adherents consider themselves to be "in the Truth".<ref>{{cite book | last = Holden | first = Andrew | title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement | publisher = Routledge | year = 2002 | page = 64 | isbn = 0415266092}}</ref> Jehovah's Witnesses regard secular [[society]] as a place of moral contamination under the influence of [[Satan]], and limit their social interaction with non-Witnesses.<ref>{{cite book | last = Holden | first = Andrew | title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement | publisher = Routledge | year = 2002 | pages = 11–12, 109–112 | isbn = 0415266092}}</ref>

Baptized members who violate the organization's fundamental moral principles or who dispute doctrinal matters can be subject to [[church discipline|disciplinary]] action. Members who are considered unrepentant after counseling may be subject to a form of [[shunning]] called [[disfellowshipping]].<ref>{{cite book | last = Hodlen | first = Andrew | title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement | publisher = Routledge | year = 2002 | page = 77 | isbn = 0415266092}}</ref><ref name=freedom>{{cite book| last = Franz| first = Raymond| authorlink = Raymond Franz| title = In Search of Christian Freedom| publisher = Commentary Press| year = 2007| location = Atlanta| page = 754| isbn = 0-914675-17-6}}</ref><ref>{{cite book| last = Botting| first = Heather | coauthors = Gary Botting| title = The Orwellian World of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1984| isbn = 0-8020-6545-7}}</ref> Members who formally announce their resignation from the religion are also shunned.<ref>"Disfellowshiping—How to View It", ''The Watchtower'', September 15, 1981, pages 23.</ref>

The religion's position regarding [[conscientious objector|conscientious objection]] to military service and refusal to [[salute]] national [[flag]]s has brought it into conflict with governments, particularly those that [[conscription|conscript]] citizens for military service.<ref>{{cite news|url=http://www.reuters.com/article/latestCrisis/idUSL15452518|title=Armenia violates Jehovah's Witnesses' rights-Amnesty|agency=Reuters|date=16 January 2008}}</ref><ref>{{cite web|url=http://www.unhcr.org/refworld/country,,AMNESTY,,ERI,,483e27893c,0.html|title=UNHCR report|date=28 May 2008}}</ref> Consequently, activities of Jehovah's Witnesses have been banned or restricted in some countries.<ref>{{cite web|url=http://www.forum18.org/Archive.php?article_id=1036|title=Tajikistan: Jehovah's Witnesses Banned|publisher=F18News|date=18 October 2007}}</ref> Persistent legal challenges by Jehovah's Witnesses have had considerable influence on related [[legislation]] and civil rights in the [[United States]] and other countries.<ref>{{cite book | last = Penton | first = M.J. | title = Apocalypse Delayed | publisher = University of Toronto Press | year = 1997 | page = 7 | url = http://books.google.com.au/books?id=38SYXalMLeQC | isbn = 0802079733, 9780802079732}}</ref>

{{Jehovah's Witnesses}}

==History==
{{Main|History of Jehovah's Witnesses}}

[[Image:Russell Charles Taze 1911 .jpg|left|140px|thumb|[[Charles Taze Russell]] (1852–1916)]]

===1870-1916: Charles Taze Russell and the Bible Students===
In 1870, [[Charles Taze Russell]] and others formed an independent group to study the Bible; in particular, Russell cited contributions by [[Advent Christian Church]] pastor George W. Stetson, and [[George Storrs]], an [[Adventist]] preacher and former [[Millerism|Millerite]].<ref>"Working in the “Field”—Before the Harvest", ''The Watchtower'', October 15, 2000, page 28</ref><ref>"Proclaiming the Lord’s Return (1870-1914)", ''Jehovah's Witnesses-Proclaimers of God's Kingdom'', p. 44-46</ref> In 1877 Russell jointly edited a religious journal, ''Herald of the Morning'', with [[Nelson H. Barbour]]. In July 1879, after separating from Barbour, Russell began publishing the magazine ''[[The Watchtower|Zion's Watch Tower and Herald of Christ's Presence]]'',<ref name="contemporary18">{{cite book|author=Holden, A.|year=2002|title=Jehovah's Witnesses: Portrait of a Contemporary Religious Movement|page=18|publisher=Routledge}}</ref> highlighting his interpretations of biblical chronology, with particular attention to his belief that the world was in "the last days".<ref>{{cite journal|url=http://www.mostholyfaith.com/bible/Reprints/Z1879JUL.asp#R3:9|journal=Zion's Watch Tower|date=1 July 1879|title=Prospectus}}</ref> In 1881, [[Watch Tower Bible and Tract Society of Pennsylvania|Zion's Watch Tower Tract Society]] was formed in [[Pittsburgh, Pennsylvania]],<ref>{{cite book|title=Jehovah's Witnesses: Proclaimers of God's Kingdom|publisher=Watch Tower Bible & Tract Society|year=1993|page=576}}</ref> to disseminate tracts, papers, doctrinal treatises and Bibles; three years later, on December 15, 1884, Russell became president of the Society when it was legally incorporated in [[Pennsylvania]].<ref name="contemporary18"/>

''Watch Tower'' supporters gathered as autonomous congregations to study the Bible and Russell's writings. Russell firmly rejected as "wholly unnecessary" the concept of a formal organization for his followers, and declared that his group had no record of its members' names, no creeds, and no sectarian name.<ref name=Franz4>{{cite book|author=Franz, Raymond|title=In Search of Christian Freedom|publisher=Commentary Press|year=2007|chapter=Chapter 4}}</ref> In 1910 he announced that the group would identify itself as the International Bible Students Association.<ref name=Franz4 /><ref>''Watchtower'', April 1910.</ref> Russell died on October 31, 1916, and control of the ''Watch Tower'' magazine was temporarily passed to an editorial committee as outlined in Russell's will, with an executive committee in control of the society pending the election of a new president.<ref>{{cite book|title=Jehovah's Witnesses - Proclaimers of God's Kingdom|chapter=A Time of Testing (1914-1918)|page=64}}</ref>

===1917-1942: Joseph Rutherford===
====Organizational changes====
In January 1917, the Watch Tower Society's legal representative, [[Joseph Franklin Rutherford]], was elected as its next president. A power struggle developed between Rutherford and four of the Watch Tower Society's board of directors, who objected to his style of leadership.<ref name=Penton>{{cite book|author=Penton, M. J.|title=Apocalypse Delayed: The Story of Jehovah's Witnesses|publisher=University of Toronto Press|year=1997|isbn=0802079733}}</ref><ref name=crisis3>{{cite book|author=Franz, Raymond|title=Crisis of Conscience|publisher=Commentary Press|year=2002|chapter=Chapter 3}}</ref> On July 17, 1917, Rutherford replaced four of the directors, claiming they had not been legally elected.<ref>{{cite book|author=A.H. Macmillan|title=Faith on the March|page=80|url=http://www.quotedstatements.com/FOTM.pdf|accessdate=2007-10-25|format=PDF}}</ref>

On the same day, he also announced the release of ''The Finished Mystery'' as the seventh volume of Russell's ''[[Studies in the Scriptures]]'' series. The book was widely advertised to the public as "a posthumous publication ... of Charles Taze Russell", though much was actually written by two other Bible Students under the direction of Joseph Rutherford.<ref>{{google books|dDQSOQV2RBIC|The Finished Mystery}}</ref><ref>{{PDFlink|[http://www.a2z.org/wtarchive/docs/The_Finished_Mystery.pdf ''The Finished Mystery'']|19.0 MB}}</ref> ''The Finished Mystery'' strongly criticized Catholic and Protestant clergy and Christian involvement in war.<ref>{{cite book|title=The Finished Mystery|url=http://www.strictlygenteel.co.uk/finishedmystery/fmr16.html|chapter=The Revelation|pages=247–253}}</ref> Patriotic fervor during [[World War I]] and other animosities fueled persecution of the Bible Students in America and Europe,<ref>{{cite journal|journal=The Golden Age|title=Distress of Nations: Cause, Warning, Remedy|pages=712–718|year=1920|month=September 29|url=http://www.a2z.org/wtarchive/docs/1920_Golden_Age.pdf|format=PDF|accessdate=2008-12-30}}</ref> including mob violence and [[tarring and feathering]].<ref name=Penton/>

Citing this book, the United States federal government indicted Rutherford and the new board of directors for violation of the ''[[Espionage Act]]'' on May 7, 1918. They were found guilty and sentenced concurrently to 20 years' imprisonment.<ref>''Proclaimers,'' p. 252.</ref> During their imprisonment, elections for the Watch Tower Society directors took place again, and Rutherford was re-elected as president.<ref>''Proclaimers,'' p. 74.</ref> In March 1919, the judgment against them was reversed and they were released from prison;<ref>{{cite court|litigants=Rutherford et al. vs. the United States|year=1918}} See also {{cite web|url=http://www.pastor-russell.com/misc/jfrdoc.html|title=Application for Executive Clemency|year=1919}}, {{cite web|format=PDF|url=http://www.watchtowerdocuments.com/downloads/1919_May_14__Appeals_Court_reverses_conviction_of_WT_Directo.pdf|title=Reversal by Appeals Court|accessdate=2008-12-30}}</ref> the charges were later dropped.<ref>{{cite book|title=Apocalypse Delayed|author=M.J. Penton|pages=55–56}}</ref><ref>{{google books|38SYXalMLeQC|Apocalypse Delayed}}</ref><ref>{{cite book|title=Jehovah's Witnesses—Proclaimers of God's Kingdom|publisher=Watch Tower Bible & Tract Society|year=1993|pages=647–654}}</ref><ref>Rutherford gives his defense against the charges in the tract [http://www.strictlygenteel.co.uk/tracts/1919_Case_of_the_IBSA.pdf ''The Case of the IBSA'']</ref>

Opposition to Rutherford among the Bible Students increased, prompting a significant number of members to cut ties with the Watch Tower Society and form new organizations.<ref>Alan Rogerson, ''Millions Now Living Will Never Die'', Constable, 1969, pages 38-44.</ref> Rutherford continued to tighten and centralize organizational control of those who remained loyal to the Watch Tower Society, with the Brooklyn headquarters appointing a "director" in each congregation in 1919, and a year later instructing all congregation members who participated in the preaching work to report their preaching activity weekly.<ref name=Franz4 />

In 1925, following a dispute over a proposed article, Rutherford overruled the ''Watch Tower'''s editorial committee and took full control of the organization and of material published in the magazine.<ref name=crisis3 /><ref>{{cite book |last = Wills |first = Tony |title = A People For His Name | publisher = Lulu Enterprises |year = 2006 |isbn = 9781430301004|pages =120–121}}</ref> On July 26, 1931, the name ''Jehovah's witnesses'' was adopted by resolution at a convention in [[Columbus, Ohio]], based on the scripture at Isaiah 43:10: "Ye are my witnesses, saith the Lord"<ref>"A New Name", ''The Watch Tower'', October 1, 1931, page 296-297.</ref><ref>"Riches of the Full Assurance of Our Understanding", ''The Watchtower'', October 15, 1950, page 387.</ref> In 1932, Rutherford eliminated the system of selecting elders by congregational vote. In 1938, he introduced a "theocratic" or "God-ruled" organizational system, under which all appointments in congregations worldwide were made from the Brooklyn headquarters.<ref name=Franz4 />

====Doctrinal changes====
At an international convention held at [[Cedar Point]], Ohio, in September 1922, a new emphasis was made on house-to-house preaching.<ref>{{cite book|title=Jehovah's Witnesses—Proclaimers of God's Kingdom|publisher=Watch Tower Bible & Tract Society|year=1993|pages=72–77}}</ref> Significant changes in doctrine were made under Rutherford's leadership, including the 1918 announcement that Jewish patriarchs (such as [[Abraham]] and [[Isaac]]) would be resurrected in 1925, marking the beginning of [[Christ]]'s thousand-year reign.<ref name="christian144">{{cite book|author=Franz, Raymond|title=In Search of Christian Freedom|year=2007|page=144}}</ref><ref>{{cite book|author=Gruss, Edmond C.|title=Jehovah's Witnesses: Their Claims, Doctrinal Changes, and Prophetic Speculation. What Does the Record Show?|publisher=Xulon Press|year=2001|isbn=193123230X|chapter=Chapter 24}}</ref><ref>''Salvation'', Watch Tower Society, 1939, as cited in ''Jehovah's Witnesses—Proclaimers of God's Kingdom'', page 76</ref> Failed expectations for 1925, coupled with other doctrinal changes, resulted in a dramatic reduction in attendance at their yearly [[Beliefs and practices of Jehovah's Witnesses#Memorial of Christ's death|Memorial]], from 90,434 in 1925<ref>{{cite book|title=Your Will Be Done on Earth|publisher=Watch Tower Bible & Tract Society|year=1958|page=337}}</ref> to 17,380 in 1928.<ref>{{cite book|title=Jehovah's Witnesses in the Divine Purpose|publisher=Watch Tower Bible & Tract Society|year=1959|page=313}}</ref><ref name="Penton 1997 61-62">{{cite book | last = Penton | first = M.J. | title = Apocalypse Delayed | publisher = University of Toronto Press | year = 1997 | page = 58, 61–62 | isbn = 0802079733, 9780802079732}}</ref> In 1932 it was announced the Jews had no special role in God's earthly kingdom<ref>{{cite book | last = Penton| first = M. James | authorlink = James Penton| title = Apocalypse Delayed: The Story of Jehovah's Witnesses| publisher = University of Toronto Press| page=65| date = 1997, 2nd ed.| isbn = 0-8020-7973-3}}</ref> and by 1933, the timing of the beginning of Christ's presence (Greek: ''parousía''), his enthronement as king, and the start of the "[[end times|last days]]", were each moved to 1914.<ref name="christian144"/><ref>{{cite book|title=The Harp of God|year=1921|pages=231–236}} states that "the Lord's second presence dates from 1874."</ref><ref>{{google books|Fjw3AAAAMAAJ|The Harp of God}}</ref><ref>{{cite journal|title=Watchtower|page=71|year=1922|month=March 1|publisher=Watch Tower Bible & Tract Society}} and {{cite book|pages=65–66|title=Prophecy|year=1930}} supported 1874.</ref><ref>{{cite book|title=Historical Idealism and Jehovah's Witnesses|pages=3–37|author=Thomas Daniels|url=http://www.catholic-forum.com/members/popestleo/Historical%20Idealism%20and%20Jehovahs%20Witnesses.pdf|accessdate=2006-02-01|format=PDF}}</ref>
From 1935, it was considered that converts to the movement, if worthy, would survive [[Armageddon]] and live in a paradise restored on earth. Previously, membership was generally composed of those who believed they would be resurrected to live in heaven to rule over the earth with Christ.<ref>{{cite book|title=Jehovah's Witnesses—Proclaimers of God's Kingdom|publisher=Watch Tower Bible & Tract Society|year=1993|pages=84–85}}</ref>

As their interpretations of scripture continued to develop, Witness publications taught that saluting national flags and standing for the [[national anthem]] are forms of idolatry. They were also instructed to refuse alternative service provided for [[conscientious objector]]s. (Objection to alternative civilian service was maintained until 1996, when it was deemed a "conscience matter".)<ref>{{cite journal|journal=The Watchtower|date=1 May 1996|page=19|title=Paying Back Caesar’s Things to Caesar}}</ref><ref>{{cite journal|journal=The Watchtower|date=15 August 1998|title=Strengthening Our Confidence in God’s Righteousness|page=17}}</ref> In Germany, Jehovah's Witnesses came under persecution, with as many as 5000 imprisoned in [[concentration camps]].<ref>{{cite web|title=United States Holocaust Memorial Museum|url=http://www.ushmm.org/wlc/article.php?lang=en&ModuleId=10005394|accessdate=February 22, 2005}}</ref><ref>{{cite book|title=Persecution and Resistance of Jehovah's Witnesses During the Nazi Regime|author=Hesse, Hans|url=http://books.google.com/books?visbn=3861087502&id=mcxD0qxHMO0C&printsec=frontcover|year=2001|page=10}}</ref> Witnesses experienced mob violence in the United States, and their activities were banned in Canada and Australia because of their refusal to accept military service.<ref>{{cite book|title=The Persecution of Jehovah's Witnesses|author=American Civil Liberties Union|url=http://www.theocraticlibrary.com/downloads/The_Persecution_of_Jehovah's_Witnesses_-_ACLU.pdf|year=1941|pages=1–24|format=PDF|accessdate=2008-12-30}}</ref><ref>{{cite book|title=Visions of Glory|author=Harrison, Barbara|authorlink=Barbara Grizzuti Harrison|pages=185, 281|year=1978|url=http://www.exjws.net/vg.htm}}</ref><ref>{{cite court |litigants=Adelaide Company of Jehovah's Witnesses, Inc. v. The Commonwealth of Australia |vol=67 |opinion=116 |format=PDF |pinpoint=124 |url=http://cchasson.free.fr/deposit/trial/Adelaide%20Company%20of%20Jehovah's%20Witnesses%20Inc%20V%20The%20Commonwealth%20of%20Australia..pdf |accessdate=2008-12-30}} (PDF, 68MB)</ref>

===1942-present: Knorr, Franz, Henschel and Adams===
Following Rutherford's death in January 1942, [[Nathan H. Knorr|Nathan Knorr]] was named the third president of the Watch Tower Bible and Tract Society. Knorr instituted major new training programs—the ''Theocratic Ministry School'' for all congregation members, and the ''[[Watchtower Bible School of Gilead|Gilead School]]'' for missionaries. He also organized large-scale conventions, which attracted as many as 253,000 Witnesses to sports stadiums in the United States, Canada and Germany,<ref>{{cite book|author=Penton, M. J.|title=Apocalypse Delayed|publisher=University of Toronto Press|year=1997|page=86}}</ref> and began a campaign of [[real estate]] acquisition in Brooklyn to expand the organization's world headquarters. He commissioned a new translation of the Bible, which was released progressively from 1950 before being published as the complete ''[[New World Translation of the Holy Scriptures]]'' in 1961. Knorr's vice-president, [[Frederick W. Franz|Frederick William Franz]], became the religion's leading [[theology|theologian]],<ref>{{cite book|author=Franz, Raymond|title=Crisis of Conscience|publisher=Commentary Press|year=2007|page=72}}</ref> and helped shape the further development of explicit rules of conduct among members.

[[Image:Casaemcasa.jpg|thumb|left|Jehovah's Witnesses are known for their preaching from house to house.]]From 1938 to 1955, the Witnesses launched a series of cases in the US Supreme Court to defend their right to worship and proselytize, winning 36 out of 45 cases.<ref>{{cite book|author=Penton, M. J.|title=Apocalypse Delayed|publisher=University of Toronto Press|year=1997|page=89}}</ref> Cases were also fought successfully in Canada and Australia.<ref>{{Cite book | last = Kaplan| first = William | title = State and Salvation" The Jehovah's Witnesses and their Fight for Civil Rights | publisher = University of Toronto Press | year = 1989 | location = Toronto | isbn = 0802058426}}</ref>

From 1966, Witness publications began using their interpretations of biblical chronology to heighten anticipation of Christ's thousand-year millennial reign beginning in late 1975.<ref>{{cite book|title=Life Everlasting in Freedom of the Sons of God|publisher=Watch Tower Bible & Tract Society|year=1966|format=PDF|url=http://www.strictlygenteel.co.uk/lifeeverlasting/1966_Life_Everlasting.pdf|pages=29–35|accessdate=2009-06-21}}</ref><ref>{{cite journal|title=How Much Longer Will It Be?|journal=Awake!|year=1966|month=October 8|pages=17–20}}</ref><ref>{{cite journal|title=Awake!|publisher=Watch Tower Bible & Tract Society|page=14|date=October 8, 1968|quote="Does this mean that the above evidence positively points to 1975 as the complete end of this system of things? Since the Bible does not specifically state this, no man can say...If the 1970s should see intervention by Jehovah God to bring an end to a corrupt world drifting toward ultimate disintegration, that should surely not surprise us."}}</ref> Focus on 1975 was intensified with talks given at conventions;<ref>{{cite book|author=Franz, Raymond|title=Crisis of Conscience|chapter=Chapter 9}}</ref><ref>{{cite book|author=Penton, M. J.|title=Apocalypse Delayed|publisher=University of Toronto Press|year=1997|page=95}}</ref><ref>{{cite book| last = Botting| first = Heather| coauthors = Gary Botting| title = The Orwellian World of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1984| page = 46| isbn = 0-8020-6545-7}}</ref> in 1974 a Watch Tower Society newsletter commended Witnesses who had sold homes and property to devote themselves to preaching in the "short time" remaining.<ref>{{cite journal|journal=[[Our Kingdom Ministry]]|month=May|year=1974|title=How Are You Using Your Life?|page=63|quote=Reports are heard of brothers selling their homes and property and planning to finish out the rest of their days in this old system in the pioneer service. Certainly this is a fine way to spend the short time remaining before the wicked world’s end.}}</ref> The number of baptisms increased significantly, from about 59,000 in 1966 to more than 297,000 in 1974, but membership declined after expectations for the year were proved wrong.<ref>{{cite book|title=Crisis of Conscience|author=Franz, Raymond|chapter=1975—The Appropriate Time for God to Act|pages=237–253|url=http://web.archive.org/web/20031209184316/http://users.volja.net/izobcenec4/coc/9.pdf|accessdate=2006-07-27|format=PDF}}</ref><ref>{{cite journal|author=Singelenberg, Richard|url=http://www.watchtowerinformationservice.org/index.php/dates/the-1975-prophecy-and-its-impact-among-dutch-jehovahs-witnesses/|title=The '1975'-prophecy and its impact among Dutch Jehovah's Witnesses|journal=Sociological Analysis|issue=1|year=1989|pages=23–40|volume=50|doi=10.2307/3710916}} Notes a nine percent drop in total publishers (door-to-door preachers) and a 38 per cent drop in pioneers (full-time preachers) in the Netherlands.</ref><ref>{{cite journal|title=The Journal of Contemporary Religion|article=Why the Jehovah's Witnesses Grow So Rapidly: A Theoretical Application|url=http://www.geocities.com/rogueactivex/JWGrow-O.pdf|year=1997|pages=142–143|format=PDF|accessdate=2008-12-30|author=Stark and Iannoccone}}</ref><ref>{{cite news|date=January 30, 1982|work=Los Angeles Times|title=Defectors Feel 'Witness' Wrath: Critics say Baptism Rise Gives False Picture of Growth|author=Dart, John|page=B4}} Cited statistics showing a net increase of publishers worldwide from 1971–1981 of 737,241, while baptisms totaled 1.71 million for the same period.</ref> In 1980, the Watch Tower Society admitted its responsibility in building up hope regarding 1975.<ref>{{cite journal|title=The Watchtower|date=March 15, 1980|page=17|quote=With the appearance of the book ''Life Everlasting—in Freedom of the Sons of God'', ... considerable expectation was aroused regarding the year 1975. ... there were other statements published that implied that such realisation of hopes by that year was more of a probability than a mere possibility. It is to be regretted that these latter statements apparently overshadowed the cautionary ones and contributed to a buildup of the expectation already initiated. ... ''persons having to do with the publication of the information'' ... contributed to the buildup of hopes centered on that date.}}</ref>

The offices of elder and ministerial servant were restored to Witness congregations in 1972, with appointments being made from headquarters.<ref>{{cite book|title=Jehovah's Witnesses—Proclaimers of God's Kingdom|publisher=Watch Tower Bible & Tract Society|page=106|year=1993}}</ref> In a major organizational overhaul in 1976, the power of the Watch Tower Society president was diminished, with authority for doctrinal and organizational decisions passed to the religion's [[Governing Body of Jehovah's Witnesses|Governing Body]].<ref>{{cite book|title=1977 Yearbook of Jehovah's Witnesses|page=258}}</ref> Reflecting these organizational changes, publications of Jehovah's Witnesses began using the capitalized name, ''Jehovah's ''W''itnesses''.<ref>First occurrence: {{cite journal|journal=Awake!|date=22 March 1976|page=3|title=Cruelties Go Unchecked in Malawi}}</ref> Prior to this, ''witnesses'' was consistently uncapitalized, except in headings and when quoting external sources. Following Knorr's death in 1977, the position of president has been occupied by [[Frederick William Franz|Frederick Franz]] (1977–1992), [[Milton George Henschel|Milton Henschel]] (1992–2000) and [[Don A. Adams]] (2000-). The office now moves on a rotational basis among members of the Governing Body.

{{See also|Development of Jehovah's Witnesses doctrine}}
{{See also|Persecution of Jehovah's Witnesses in Nazi Germany|Supreme Court cases involving Jehovah's Witnesses by country}}

==Organization==
{{Main|Organizational structure of Jehovah's Witnesses}}
Jehovah's Witnesses are organized under a [[hierarchy|hierarchical]] arrangement, which their leadership calls a "theocratic government", reflecting their belief that it is God's organization on earth.<ref name=pentongov>{{cite book| last = Penton| first = M. James| title = Apocalypse Delayed: The Story of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1997| pages = 211–252| isbn = 0-8020-7973-3}}</ref>

The organization is headed by the [[Governing Body of Jehovah's Witnesses|Governing Body]]—an all-male group that varies in size, but since 2007 has comprised nine members,<ref>Twelve members as of September 2005 (See ''The Watchtower'', March 15, 2006, page 26) Schroeder died March 8, 2006 (See ''The Watchtower'', September 15, 2006, page 31) Sydlik died April 18, 2006 (See ''The Watchtower'', January 1, 2007, page 8) Barber died April 8, 2007 (See ''The Watchtower'', October 15, 2007, page 31)</ref> all of whom profess to be of the "anointed" class with a hope of heavenly life—based in the Watch Tower Society's [[Brooklyn, New York]] headquarters.<ref>{{cite book|title=2007 Yearbook of Jehovah's Witnesses|author=Watch Tower Bible and Tract Society of Pennsylvania|pages=4, 6}}</ref><ref>{{cite book| last = Botting| first = Heather & Gary| title = The Orwellian World of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1984 | isbn = 0-8020-6545-7}}</ref> There is no election for membership; new members are selected by the existing body.<ref>{{cite book| last = Franz| first = Raymond| title = In Search of Christian Freedom| publisher = Commentary Press| year = 2007| location = | page = 123| isbn = 0-914675-17-6}}</ref> The Governing Body is described as the "spokesman" for God's "[[faithful and discreet slave]] class" (the approximately 10,800 remaining "anointed" Jehovah's Witnesses),<ref>{{cite book| last = Franz| first = Raymond| title = In Search of Christian Freedom| publisher = Commentary Press| year = 2007| page = 153| isbn = 0-914675-17-6}}</ref><ref>''Yearbook'', Watch Tower Bible and Tract Society, 2010.</ref> and is said to provide "spiritual food" for Witnesses worldwide on behalf of the "faithful and discreet slave". In practice it does not seek advice or approval from any "anointed" Witnesses other than high-ranking members at Brooklyn Bethel when formulating policy and doctrines or when producing material for publications and conventions.<ref>"The faithful slave and its governing body", ''The Watchtower'', June 15, 2009, pages 23-24.</ref><ref>{{cite book| last = Franz| first = Raymond| title = In Search of Christian Freedom| publisher = Commentary Press| year = 2007| pages = 154–164| isbn = 0-914675-17-6}}</ref>

The Governing Body directs several committees that are responsible for various administrative functions, including publishing, assembly programs and evangelizing activities.<ref name=pentongov /> It directly appoints all branch committee members and district and circuit overseers,<ref>''The Watchtower'', January 15, 2001, pages 14-15</ref> with traveling overseers supervising groups of congregations within their jurisdictions.

Witnesses have no formal clergy-laity division. Each congregation has a body of appointed male elders and ministerial servants. Elders maintain general responsibility for congregational governance, setting meeting times, selecting speakers and conducting meetings, directing the public preaching work, and creating "judicial committees" to investigate and decide disciplinary action for cases that are seen as breaching scriptural or organizational rules. New elders are appointed by branch offices after recommendation by the existing body of elders. Ministerial servants—appointed in a similar fashion to elders—fulfill clerical and attendant duties, but may also teach and conduct meetings.<ref name=pentongov />

Witness publications place strong emphasis on the need for members to be obedient and loyal to the Watch Tower organization,<ref>{{cite book | last = Gruss | first = Edmond C.| title = The Four Presidents of the Watch Tower Society| publisher = Xulon Press | year = 2003 | pages = 56–63 | isbn =1594671313 }}</ref><ref>{{cite book|last=Franz|first=Raymond|title=In Search of Christian Freedom|publisher=Commentary Press|year=2007|pages=449–464.}}</ref><ref>"Following Faithful Shepherds with Life in View", ''The Watchtower'', October 1, 1967, page 591, "Make haste to identify the visible theocratic organization of God that represents his king, Jesus Christ. It is essential for life. Doing so, be complete in accepting its every aspect."</ref> warning that individuals must remain part of it to receive God's favour and also to survive Armageddon.<ref>''You Can Live Forever in Paradise on Earth'', Watch Tower Bible and Tract Society, 1989, page 255, "It is simply not true that all religions lead to the same goal. (Matthew 7:21-23; 24:21) You must be part of Jehovah’s organization, doing God’s will, in order to receive his blessing of everlasting life."</ref><ref>"You Can Live Forever in Paradise on Earth—But How?", ''The Watchtower'', February 15, 1983, page 12, "Jehovah is using only one organisation today to accomplish his will. To receive everlasting life in the earthly Paradise we must identify that organisation and serve God as part of it."</ref><ref>"Serving Jehovah Loyally", ''The Watchtower'', November 15, 1992, page 21, "I determined to stay by the faithful organisation. How else can one get Jehovah’s favour and blessing?” There is nowhere else to go for divine favour and life eternal."</ref> Publications state that acceptable service to God can be rendered only through that organization<ref>"Greater Blessings Through the New Covenant", ''The Watchtower'', February 1, 1998, page 17, "Those of spiritual Israel still remaining on earth make up 'the faithful and discreet slave.' ... Only in association with them can acceptable sacred service be rendered to God."</ref> and that members should remain submissive to the religion's leaders and local congregational elders.<ref>"Be Aglow With the Spirit", ''The Watchtower'', October 15, 2009, "Those with an earthly hope should therefore recognise Christ as their head and be submissive to the Faithful and Discreet Slave and its Governing Body and to the men appointed as overseers in the congregation."</ref><ref>"Move Ahead with Jehovah’s Organisation", ''The Watchtower'', June 1, 1967, page 337, "What, can we say, is the basic principle underlying the movement of Jehovah’s living organisation? It can be expressed in one word: OBEDIENCE. Loving obedience from the heart is all. This is the basic formula upon which the organisation rests and operates." (Emphasis in original.)</ref>

==Beliefs==

{{christianity |expand-nontrinitarian=yes |no-cross=yes}}
{{Main|Beliefs and practices of Jehovah's Witnesses}}
===Sources of doctrine===
[[Doctrine]]s of Jehovah's Witnesses are established by the [[Governing Body of Jehovah's Witnesses|Governing Body]], which assumes responsibility for [[exegesis|interpreting]] and [[eisegesis|applying scripture]].<ref name="Penton 1997 61-62"/><ref>''Organized to Do Jehovah's Will'', Watch Tower Bible & Tract Society, 2005, pages 17-18.</ref><ref>"Cooperating With the Governing Body Today,", ''The Watchtower'', March 15, 1990, page 19.</ref> Prior to the reorganization of the Governing Body in 1976,<ref>"Serving with the Faithful Slave", ''The Watchtower'', January 1, 1977, pages 14-15.</ref> matters of doctrine were decided by the president of the [[Watch Tower Society]].<ref>Alan Rogerson, ''Millions Now Living Will Never Die'', Constable, 1969, page 46.</ref><ref>Testimony by Fred Franz, Transcript, Lord Strachan vs. Douglas Walsh, 1954. page 100, "The President is the mouthpiece. He pronounces the speeches that show advancement of the understanding of the Scriptures ... Q: Tell me, are these advances, as you put it, voted upon by the Directors? A: No... they go through the Editorial Committee, and I give my OK after scriptural examination. Then I pass them on to President Knorr, and President Knorr has the final OK. Q: Does it go before the Board of Directors at all? A: No. "</ref> Watch Tower publications claim that doctrinal changes and refinements result from a process of progressive [[revelation]], in which God gradually reveals his will and purpose.<ref>{{cite journal|journal=The Watchtower|title=Focus on the Goodness of Jehovah's Organisation|page=22|date=15 July 2006}}</ref><ref>"Impart God’s Progressive Revelation to Mankind", ''The Watchtower'', March 1, 1965, p. 158-159</ref><ref>{{cite book|author=Penton, M. J. Penton|title=Apocalypse Delayed|publisher=University of Toronto Press|pages=165–171}}</ref><ref>Flashes of Light—Great and Small", ''The Watchtower'', May 15, 1995, page 15.</ref><ref>''Jehovah's Witnesses, Proclaimers of God's Kingdom'', Watch Tower Bible & Tract Society, 1993, page 709.</ref> Watch Tower literature has suggested such enlightenment results from the application of [[reason]] and [[biblical studies|study]],<ref>{{cite book | last = Penton | first = M.J. | title = Apocalypse Delayed | publisher = University of Toronto Press | year = 1997 | page = 165 | isbn = 0802079733, 9780802079732}}</ref> the guidance of the [[holy spirit]], and direction from [[Jesus Christ]] and [[angels]].<ref>J. F. Rutherdford, ''Preparation'', Watch Tower Bible & Tract Society, 1933, page 64, 67, "Enlightenment proceeds from Jehovah by and through Christ Jesus and is given to the faithful anointed on earth at the temple, and brings great peace and consolation to them. Again Zechariah talked with the angel of the Lord, which shows that the remnant are instructed by the angels of the Lord. The remnant do not hear audible sounds, because such is not necessary. Jehovah has provided his own good way to convey thoughts to the minds of his anointed ones ... Those of the remnant, being honest and true, must say, We do not know; and the Lord enlightens them, sending his angels for that very purpose."</ref> However, the Governing Body makes no claim of [[infallibility of the Church|infallibility]] or divine inspiration.<ref>"To Whom Shall We Go but Jesus Christ?", ''The Watchtower'', March 1, 1979, pages 23-24.</ref><ref>"Questions From Readers", ''The Watchtower'', October 15, 1954, page 638.</ref><ref>"Name and Purpose of The Watchtower", ''The Watchtower'', August 15, 1950, page 263.</ref>

The entire Protestant [[Biblical canon|canon of scripture]] is considered the [[Biblical inspiration|inspired]], [[Biblical inerrancy|inerrant]] word of God.<ref>{{cite book|author=Penton, M. J.|title=Apocalypse Delayed|publisher=University of Toronto Press|edition=2nd|year=1997|page=172}}</ref> The Witnesses accept the Bible as [[Science and the Bible|scientifically]] and [[The Bible and history|historically]] accurate and reliable<ref>''All Scripture is Inspired of God'', Watch Tower Bible & Tract Society, 1990, page 336.</ref> and interpret much of it [[Biblical literalism|literally]], but accept parts of it as [[Allegorical interpretation|symbolic]].<ref>''All Scripture is Inspired of God'', Watch Tower Bible & Tract Society, 1990, page 9.</ref> They consider the Bible to be the source of truth<ref>"Seek God's Guidance in All Things", ''Watchtower'', April 15, 2008,</ref> and the basis for all their beliefs.<ref>''Reasoning From The Scriptures'' | p. 199 - p. 208 Jehovah’s Witnesses</ref> Sociologist Andrew Holden's [[Ethnography|ethnographic]] study of the religion concluded that pronouncements of the Governing Body, through Watch Tower Society publications, carry as much or more weight than the Bible.<ref>{{cite book | last = Holden | first = Andrew | title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement | publisher = Routledge | year = 2002 | page = 67 | isbn = 0415266092}}</ref> The leadership of Jehovah's Witnesses claims to be the sole visible channel of Jehovah and asserts that the Bible cannot be understood without associating with the Watch Tower Society.<ref>{{cite journal|journal=The Watchtower|date=1 October 1967|pages=587,590|publisher=Watch Tower Bible & Tract Society}}</ref><ref>{{cite journal|journal=The Watchtower|date=1 November 1961|page=668|publisher=Watch Tower Bible & Tract Society}}</ref><ref>"Accept Jehovah's Authority", ''Watchtower'', June 15, 2008.</ref>

===Jehovah and Jesus Christ===

Jehovah's Witnesses emphasize use of [[God]]'s biblical name, the [[Tetragrammaton]], and in English they prefer to use the name, ''[[Jehovah]]''.<ref>{{cite book|author=Holden, A.|year=2002|title=Cavorting With the Devil: Jehovah’s Witnesses Who Abandon Their Faith|page=Endnote [i]|publisher=Department of Sociology, Lancaster University, Lancaster LA1 4YL, UK|url=http://www.lancs.ac.uk/fass/sociology/papers/holden-cavorting-with-the-devil.pdf|format=PDF|accessdate=2009-06-21}}</ref> Jehovah's Witnesses believe that Jehovah is the only true God, the creator of all things, and give him the title "Universal Sovereign". They believe that all worship should be directed toward him.<ref name="proclaimers144">{{cite book|title=Jehovah's Witnesses—Proclaimers of God's Kingdom|year=1993|pages=144–145}}</ref>

[[Image:YHWH.svg|thumb|left|120px|The [[Tetragrammaton]]]]

Jehovah's Witnesses believe that [[Jesus]] was Jehovah's first and only direct creation,<ref>{{cite book|title=Insight on the Scriptures|volume=2|year=1988|page=1019}}</ref> that Jehovah then created everything else by means of Christ, and that the initial unassisted act of creation uniquely identifies Jesus as God's "only-begotten Son".<ref>{{cite journal|title=Jesus Christ—God’s Beloved Son|journal=The Watchtower|date=June 1, 1988|page=13}}</ref><ref>{{cite book|title=Insight on the Scriptures|publisher=Watch Tower Bible & Tract Society|year=1988|volume=2|pages=556–557|chapter=Only-begotten}}</ref> Jesus served as a redeemer and a ransom sacrifice to pay for the sins of humankind.<ref>{{cite book|title=Insight on the Scriptures|volume=2|publisher=Watch Tower Bible & Tract Society|pages=60–61|chapter="His Vital Place in God's Purpose" and "Chief Agent of life"}}</ref> They believe that Jesus died on a single upright [[torture stake]] rather than the traditional [[Crucifixion of Jesus|cross]].<ref>{{cite book|title=Reasoning From the Scriptures|year=1989|pages=89–90}}</ref> They believe that references in the Bible to the [[Michael (archangel)|Archangel Michael]], [[Apollyon]] (a.k.a. [[Abaddon]]), and [[Christ the Logos|the Word]] all refer to Jesus.<ref>{{cite journal|title=Angels: How They Affect Us|date=15 January 2006|journal=The Watchtower|publisher=Jehovah's Witnesses}}</ref><ref>{{cite book|title=Insight on the Scriptures|volume=2|year=1988|pages=393–394}}</ref><ref>{{cite book|title=Insight on the Scriptures|volume=1|year=1988|pages=12, 126}}</ref>

===Satan===
Jehovah's Witnesses believe that [[Satan]] is a spirit creature who is the ruler of the world,<ref name="proclaimers144"/><ref>{{cite book|title=What Does the Bible Really Teach?|year=2005|page=32|publisher=Watch Tower Bible & Tract Society}}</ref><ref>{{cite book |title=Insight on the Scriptures |volume=2 |year=1988 |page=866 |chapter=Satan}}</ref><ref>{{cite book|title=Reasoning From the Scriptures|year=1989|page=361|publisher=Watch Tower Bible & Tract Society}}</ref> and that he was at one time a perfect [[angel]] who developed feelings of self-importance, and craved worship. Satan persuaded Adam and Eve to obey him rather than God, and humanity subsequently become participants in a challenge involving the competing claims of Jehovah and Satan to universal sovereignty.<ref name="proclaimers144"/><ref>{{cite journal|title=The Bible Answers Vital Questions of Our Day|date=November 15, 1999|journal=The Watchtower}}</ref> Other angels who sided with Satan became [[demon]]s.<ref>''Insight on the Scriptures'' vol. 1 p. 612 Demon</ref> Jehovah's Witnesses teach that Satan and his demons were cast down to earth from heaven after October 1, 1914,<ref>
"What Has God’s Kingdom Been Doing Since 1914?", ''The Watchtower'', October 15, 1966, pages 621-622</ref><ref>"Living Now in That Last Day of Resurrection", ''The Watchtower'', June 15, 1979, page 26.</ref> at which point the [[end time]]s began.<ref name="proclaimers144"/><ref>{{cite book|title=What Does the Bible Really Teach?|year=2005|pages=87,216|publisher=Watch Tower Bible & Tract Society}}</ref> Witnesses believe that the world is under the control of Satan and his demons, that they mislead people, and are the cause of human suffering. However, they do not believe that individual rulers or governments are under Satan's direct control.<ref>''Watchtower'', April 1, 2004, "In one sense, human governments serve as 'God’s minister,' giving structure to human society, without which chaos would rule. And some leaders have protected fundamental human rights, including the right to engage in true worship—something that Satan does not want. Still, because of the Devil’s influence, no human or human institution has ever been able to bring lasting peace and security to the people."</ref><ref>"The Christian’s View of the Superior Authorities", ''The Watchtower'', November 1, 1990, page 14.</ref>

===Life after death===
Jehovah's Witnesses believe death is a state of non-existence with no [[consciousness]]. There is no [[Hell]] of fiery torment; [[Hades in Christianity|Hades]] and [[Sheol]] are understood to refer to the condition of death, termed the ''common grave''.<ref>{{cite journal |title=Is There LIFE After Death? |journal=The Watchtower |month=July 15 |year=2005 |url=http://www.watchtower.org/e/20020715/article_02.htm|accessdate=2008-09-14}}</ref><ref>{{cite journal |title=Hell—Eternal Torture or Common Grave? |journal=The Watchtower |month=April 15 |year=1993 |page=6}}</ref><ref>{{cite book |title=Insight on the Scriptures|volume=2|year=1988 |page=596 |chapter=Death}}</ref> Jehovah's Witnesses consider the [[soul]] to be the physical body that dies.<ref>{{cite book |title=Insight on the Scriptures|volume=2|year=1988 |page=1004|quote=The...Scriptures show 'soul' to be a person, an animal, or the life that a person or an animal enjoys.}}</ref> Their hope for life after death involves being resurrected by God to a cleansed earth after Armageddon, or to heaven for the limited number of 144,000. The ones remaining on earth are referred to as the "Great Crowd".

Watch Tower Society publications teach that humanity is in a [[Christian views of sin#Protestant views|sinful]] state.<ref>"Jehovah Cares For You," ''The Watchtower'', October 15, 2002, p. 15.</ref> Release from this is possible because Jesus' shed blood provided a payment, or [[substitutionary atonement|atonement]], for the sins of humankind.<ref>''Insight On The Scriptures'', Vol 2, p. 733.</ref> Witnesses believe there are two destinations for those saved by God. They interpret Revelation 14 to mean that the number of Christians going to heaven is limited to precisely 144,000, who will rule with Jesus as kings and priests over earth.<ref>"Have No Fear, Little Flock", ''The Watchtower'', February 15, 1995, p. 18-22.</ref> The remainder have the hope of living forever in an earthly paradise.<ref>"A Great Crowd Rendering Sacred Service," ''The Watchtower'' February 1, 1995, p. 14-17.</ref> Jehovah's Witnesses teach that only they meet scriptural requirements for surviving Armageddon, although God is the final judge.<ref name=onlyjw /><ref>''Worship the Only True God'', Watch Tower Bible & Tract Society, 2002, page 179.</ref><ref>''You Can Live Forever in Paradise on Earth,'', Watch Tower Bible & Tract Society, 1989, pg 255, "Do not conclude that there are different roads, or ways, that you can follow to gain life in God’s new system. There is only one. There was just the one ark that survived the Flood, not a number of boats. And there will be only one organization — God’s visible organization — that will survive the fast-approaching 'great tribulation.' It is simply not true that all religions lead to the same goal. You must be part of Jehovah’s organization, doing God’s will, in order to receive his blessing of everlasting life."</ref><ref>"Our Readers Ask: Do Jehovah’s Witnesses Believe That They Are the Only Ones Who Will Be Saved?", ''The Watchtower'', November 1, 2008, page 28, "Jehovah’s Witnesses hope to be saved. However, they also believe that it is not their job to judge who will be saved. Ultimately, God is the Judge. He decides."</ref><ref>:Counted worthy to be guided to fountains of waters of life", ''The Watchtower'', January 15, 2008, page 25, "...Since the growing great crowd of other sheep are viewed by God as righteous, they can hope to survive the destruction of this system of things at the great tribulation. (They can draw close to Jehovah, and as a group, they have the wonderful prospect of surviving Armageddon. They are not independent but willing to serve under the direction of the heavenly King and his anointed brothers on earth.)"</ref><ref>''The Watchtower'' July 1, 1995 p. 21 par 17,18.</ref> During the millennium, most other people who died since the time of [[Cain and Abel|Abel]] will be resurrected with the prospect of living forever;<ref>"The Only Remedy!", ''The Watchtower'', March 15, 2006, p. 6.</ref><ref>{{cite journal|journal=The Watchtower|title=Who Will Be Resurrected?|date=1 May 2005|page=17}}</ref> they will be taught the proper way to worship God in order for them to be ready for their final test before the end of the millennium.

===God's Messianic Kingdom===
Witness publications teach that God's Kingdom is a government in heaven, ruled by Jesus Christ and 144,000 Christians drawn from the earth.<ref>''The Government That Will Bring Paradise'', Watch Tower Bible & Tract Society, 1993, page 3.</ref> The kingdom is viewed as the means by which God will accomplish his original purpose for the earth,<ref>''Insight on the Scriptures,'', Watch Tower Bible & Tract Society, Vol 1, page 310.</ref><ref>''Worship the Only True God'', Watch Tower Bible & Tract Society, 2002, page 6.</ref> transforming earth into a paradise without sickness or death.<ref>''Reasoning from the Scriptures'', Watch Tower Bible & Tract Society, pages 225-234.</ref> The kingdom is said to have been the focal point of Jesus' ministry on earth<ref>"God’s Kingdom—Earth’s New Rulership", ''The Watchtower'', October 15, 2000, page 10.</ref> and established in heaven in 1914.<ref>"What Has God’s Kingdom Been Doing Since 1914?", ''The Watchtower'', October 15, 1966, page 617.</ref>

===Eschatology===
{{Main|Eschatology of Jehovah's Witnesses}}
A central teaching of Jehovah's Witnesses is that the current world era, or "system of things", entered the "[[End time|last days]]" in 1914<ref>"Deliverance by God’s Kingdom Is at Hand!", ''The Watchtower'', May 15, 2008, page 15.</ref> and faces imminent destruction through intervention by God and Jesus Christ, leading to deliverance for those who worship God acceptably. This judgment will begin with the destruction by the [[United Nations]] of false religion, which they identify as "[[Babylon the great#Jehovah.27s Witnesses|Babylon the Great]]", or the "harlot", of [[Book of Revelation|Revelation]] 17.<ref>''Revelation – Its Grand Climax at Hand'', Watch Tower Bible & Tract Society, 1988, pages 235-236.</ref> This development will mark the beginning of the Great Tribulation.<ref>"Apocalypse—When?", ''The Watchtower'', February 15, 1986, page 6.</ref> Satan will subsequently attack Jehovah's Witnesses, an action that will prompt God to begin the war of [[Armageddon]], during which all forms of government and all people not counted as Christ's "sheep", or true followers, will be destroyed.<ref>''Revelation – Its Grand Climax at Hand'', Watch Tower Bible & Tract Society, 1988, page 286.</ref> After Armageddon, God will extend his heavenly kingdom to include earth,<ref>''The Watchtower'', September 1, 1959, pp. 530-531 par. 15.</ref><ref>[http://www.watchtower.org/e/20051201/article_02.htm Armageddon—A Happy Beginning Jehovah's Witnesses Official Web Site]</ref> which will be transformed into a paradise similar to the [[Garden of Eden]].<ref>{{Harvnb|Penton|1997|p=180}}.</ref> After Armageddon, most of those who had died prior to God's intervention will gradually be resurrected to a "day of judgment" lasting for a [[Millenarianism|thousand years]].<ref>''The Watchtower'', May 15, 2006, p 6.</ref> This judgment will be based on their actions after resurrection, not on past deeds.<ref>''Insight on the Scriptures,'' Vol. 2, Watch Tower Bible & Tract Society, 1988,p. 788.</ref> At the end of the thousand years, a final test will take place when Satan is brought back to mislead perfect mankind.<ref>''The Watchtower'', May 1, 2005, p. 20.</ref> The end result will be a fully tested, glorified human race.<ref>''The Watchtower'', August 15, 2006, p. 31</ref> Christ will then hand all authority back to God.<ref>''Pay Attention to Daniel’s Prophecy!'', Watch Tower Bible and Tract Society of Pennsylvania, 2006, pp. 94,95.</ref>

Watch Tower Society publications teach that Jesus Christ returned invisibly and began to rule in heaven as king in October 1914.<ref>"Christ’s Presence—What Does It Mean to You?", ''The Watchtower'', February 15, 2008, page 21.</ref> Satan was subsequently ousted from heaven to the earth, resulting in "woe" to mankind.<ref>''The Watchtower'', February 1, 1996, p6.</ref> They assert that the Greek word ''parousia''—usually translated as "coming" when referring to Christ—is more accurately rendered as "presence", with his return perceived only as a series of "signs". This [[Second Coming]] would be an invisible presence, lasting for an extended period.<ref>"Jesus’ Coming or Jesus’ Presence—Which?", ''The Watchtower'', August 15, 1996, p. 12.</ref>

==Practices==
{{Main|Beliefs and practices of Jehovah's Witnesses}}

===Worship===
Meetings for worship and study are held at [[Kingdom Hall of Jehovah's Witnesses|Kingdom Halls]]. Kingdom Halls are typically functional in character, and do not contain religious symbols.<ref name=holdenhall /> Witnesses are assigned to a congregation in whose "territory" they reside and are expected to attend weekly services they refer to as "meetings" as scheduled by congregation elders. The meetings are largely devoted to study of the Bible and Watch Tower Society literature. The form and content of the meetings is established by the religion's Brooklyn headquarters, with the content of most meetings being identical worldwide.<ref name=holdenhall>{{cite book| last = Holden| first = Andrew| title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement| publisher = Routledge| year = 2002| pages = 64–69| isbn = 0-415-26610-6}}</ref> Congregations meet for two sessions each week comprising five distinct meetings that total about three-and-a-half hours, typically gathering mid-week (three meetings) and on the weekend (two meetings). Meetings are opened and closed with songs and prayers delivered from the platform. Each year, Witnesses from a number of congregations that form a "circuit" gather for one-day, and two-day assemblies. Several circuits meet once a year for a three-day "district convention", usually at rented stadiums or auditoriums. Their most important and solemn event is the celebration of the "Lord's Evening Meal", or "Memorial of Christ's Death", which falls on the same date as the Jewish [[Passover]].

===Evangelism===
Jehovah's Witnesses are perhaps best known for their efforts to spread their beliefs, most notably by visiting people from house to house.<ref>{{cite book|title=Jehovah's Witnesses: Proclaimers of God's Kingdom|page=570|year=1993| chapter=House-to-House Preaching —An Identifying Mark}}</ref><ref>{{cite journal|journal=The Watchtower|date=May 15, 1981|page=17|title=Showing Lifesaving Neighbor Love}}</ref> Free home Bible studies are offered to people who show interest in their beliefs, which they present with the aid of their publications, such as ''The Watchtower''. Literature is published in many languages through a wide variety of [[book]]s, [[magazine]]s and other publications, with a small selection available in over 440 languages. Witnesses are instructed to devote as much time as possible to preaching activities, and are required to provide a monthly report to their congregation on their 'witnessing' activity.<ref>{{cite book| last = Botting| first = Heather| coauthors = Gary Botting| title = The Orwellian World of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1984| page = 52| isbn = 0-8029-2537-4}}</ref>

===Ethics and morality===
[[Image:Jehovas Zeugen Königreichssaal Heimfeld 04.jpg|thumb|right|220px|Jehovah's Witnesses meet in buildings called [[Kingdom Hall]]s, like this one in Germany.]]
Their view of morality reflects conservative Christian values. All sexual relations outside of marriage are grounds for expulsion (''[[disfellowshipping]]'') if the accused is not deemed repentant.<ref>{{cite book|author=Chryssides, G.D.|year=1999|title=Exploring New Religions|page=103|publisher=Continuum International Publishing Group}}</ref><ref name="The Watchtower 1998, page 16">"Imitate Jehovah—Exercise Justice and Righteousness", ''The Watchtower'', August 1, 1998, page 16.</ref> Abortion is considered [[murder]].<ref>{{cite book|chapter=Why Living a Godly Life Brings Happiness|title=Knowledge that Leads to Everlasting Life|year=1995|page=118|publisher=Watch Tower Bible & Tract Society}}</ref> Modesty in dress and grooming is frequently emphasized. [[Gambling]],<ref>{{cite book|title=Knowledge That Leads to Everlasting Life|publisher=Watch Tower Bible & Tract Society|year=1995|page=120}}</ref> drunkenness, illegal drugs, and tobacco use are forbidden.<ref>{{cite book| last = Penton| first = M. James| title = Apocalypse Delayed: The Story of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1997| page = 280| isbn = 0-8020-7973-3}}</ref> Drinking of [[alcoholic beverage]]s is permitted in moderation.<ref>{{cite journal|journal=''The Watchtower''|page=18|date=1 December 2004|title=Maintain a Balanced View of the Use of Alcohol}}</ref>

The family structure is [[Patriarchy|patriarchal]]. The husband is considered the final authority on family decisions, but is encouraged to solicit his wife's thoughts and feelings, as well as those of his children. Marriages are required to be [[Monogamy|monogamous]].<ref>{{cite journal|title=''The Bible's Viewpoint'' What Does It Mean to Be the Head of the House?|journal=Awake!|date=July 8, 2004|page=26}}</ref> Divorce is permissible only for adultery; such a divorce is referred to as "a scriptural divorce".<ref>"Is Divorce the Answer?", ''Awake!'', September 8, 2004, page 26, "Jesus later stated that “the ground of fornication” is the only basis for Scriptural divorce with the possibility of entering a new marriage."</ref><ref>{{cite book| last = Penton| first = M. James|title = Apocalypse Delayed: The Story of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1997| page = 112| isbn = 0-8020-7973-3}}</ref> If a divorce is obtained for any other reason, remarriage is considered adultery while the previous spouse is still alive and has not begun another sexual relationship.<ref>{{cite book|title=Insight on the Scriptures|chapter=Adultery|page=53|volume=1}}</ref> Extreme physical abuse, willful non-support of one's family, and what the religion terms "absolute endangerment of spirituality" are considered grounds for legal separation.<ref>"Marriage—Why Many Walk Out", ''Awake!'', July 8, 1993, page 6, "A legal divorce or a legal separation may provide a measure of protection from extreme abuse or willful nonsupport."</ref><ref>{{cite journal|journal=The Watchtower|date=1 November 1988|page=22|title=When Marital Peace Is Threatened}}</ref>

===Disciplinary action===
{{Main|Jehovah's Witnesses and congregational discipline}}
Formal discipline is administered by congregation elders. When an accusation of what they term "[[Jehovah's Witnesses and congregational discipline#List of "serious sins"|serious sin]]" is made concerning a baptized member, a [[Jehovah's Witnesses and congregational discipline#Judicial committee|judicial committee]] is formed to determine guilt, administer help and possibly apply discipline. ''[[Jehovah's Witnesses and congregational discipline#Disfellowshipping|Disfellowshipping]]'', a form of [[shunning]], is the strongest form of discipline administered.<ref>''The Watchtower'' April 15, 1988.</ref> Contact with disfellowshipped individuals is limited to direct family members living in the same home, and with congregation elders who may invite disfellowshipped persons to apply for [[Jehovah's Witnesses and congregational discipline#Reinstatement|reinstatement]];<ref>[http://www.jw-media.org/aboutjw/article41.htm#shun Jehovah’s Witnesses Official Media Web Site: Our History and Organization], "Do you shun former members? ... If, however, someone unrepentantly practices serious sins, such as drunkenness, stealing or adultery, he will be disfellowshipped and such an individual is avoided by former fellow-worshipers. ... The marriage relationship and normal family affections and dealings can continue. ... Disfellowshipped individuals may continue to attend religious services and, if they wish, they may receive spiritual counsel from the elders with a view to their being restored. They are always welcome to return to the faith [emphasis retained from source]"</ref><ref>{{cite journal|journal=Our Kingdom Ministry|title=Display Christian Loyalty When a Relative Is Disfellowshipped|pages=3–4|date=August 2002}}</ref> formal business dealings may continue if contractually or financially obliged.<ref>{{cite journal|journal=The Watchtower|title=Disfellowshipping-How to View It|date=15 September 1981|page=24}}</ref> By avoiding social and spiritual interaction with disfellowshipped individuals, Witnesses state that the congregation is kept free from immoral influence and wrong-doers may be shamed into repentance.<ref>{{cite book|title=Keep Yourselves in God's Love|chapter=Appendix: How to Treat a Disfellowshipped person|pages=198–202|year=2008|publisher=Jehovah's Witnesses}}</ref> The threat of shunning also serves to deter other members from dissident behavior. Members who voluntarily leave the religion and formally disassociate themselves are also shunned.<ref>{{cite book| last = Holden| first = Andrew| title = Jehovah's Witnesses - Portrait of a Contemporary Religious Movement| publisher = Routledge| year = 2002| page = 163| isbn = 0-414-26610-6}}</ref><ref>"Make Wise Use of Your Christian Freedom", ''The Watchtower'', June 1, 1992, page 18.</ref><ref>"Disfellowshiping—How to View It", ''The Watchtower'', September 15, 1981, page 23.</ref> ''[[Jehovah's Witnesses and congregational discipline#Reproof|Reproof]]'' is given formally by a judicial committee to a baptized Witness who is considered repentant of "serious sin"; the reproved person temporarily loses conspicuous ''[[Jehovah's Witnesses and congregational discipline#Limited "privileges of service"|privileges of service]]'', but suffers no restriction of social or spiritual fellowship.<ref>“Questions From Readers”, ''The Watchtower'', January 1, 1983 pp. 30-31.</ref> ''[[Jehovah's Witnesses and congregational discipline#Marking|Marking]]'' is practiced if a baptized adherent persists in a course of action regarded as a violation of Bible principles but not a "serious sin".<ref>The most common example given is a baptised Witness who dates a non-Witness; see ''The Watchtower'', July 15, 1999, p. 30.</ref> Elders assign two elders to "correct" the person; if the person continues the same course, an elder delivers a [[Jehovah's Witnesses and congregational discipline#Local needs|congregation talk]] regarding "marking" (their interpretation of [http://watchtower.org/bible/2th/chapter_003.htm#bk14 2 Thessalonians 3:14]) and the Bible principle being violated.<ref>"Questions From Readers", ''The Watchtower'', July 15, 1999, page 31, "The congregation elders take the lead in offering help and counsel if someone is walking disorderly. If he does not see the error of his way but continues to be an unwholesome influence, the elders may warn the congregation by means of a talk that makes clear the Biblical view—be it of dating unbelievers, or whatever the improper course is. (1 Corinthians 7:39; 2 Corinthians 6:14) Christians in the congregation who are thus alerted can individually decide to limit any socialising"</ref><ref>"Questions From Readers", ''The Watchtower'', April 15, 1985, page 31, "...marking involves serious violations of Bible principles. First the elders try repeatedly to help the violator by admonishing him. If the problem persists, they may, without naming the person, give a warning talk to the congregation concerning the disorderly conduct involved... After that, individual Christians would keep the erring person “marked.”
Good judgment is needed rather than predetermined rules about every aspect of marking. ...[Elders] can use reasonableness and discernment in determining whether a particular situation is sufficiently serious and disturbing so as to require a warning talk to the congregation. ...For example, elders should exercise discernment in dealing with a Christian who is dating a person not “in the Lord.”"</ref> Members familiar with the marked person's course of action are expected to limit social fellowship (but continue spiritual fellowship) with that person; the stated purpose is to shame the person into correcting their actions.<ref>Questions From Readers, ''The Watchtower'', April 15, 1985, p. 31.</ref>

===Separateness===
{{Main|Jehovah's Witnesses and governments}}

Jehovah's Witnesses believe that the Bible condemns the mixing of religions, on the basis that there can only be one truth from God, and therefore reject interfaith and ecumenical movements.<ref>{{cite journal|date=15 December 1953|title=Should the Religions Unite?|journal=The Watchtower|pages=741–742}}</ref><ref>{{cite journal|date=1 February 1952|title=Is Interfaith God's Way?|journal=The Watchtower|page=69}}</ref><ref>{{cite journal|date=22 November 1989|title=Religion’s Future in View of Its Past Part 22—1900 onward—False Religion—Overtaken by Its Past!|journal=Awake!|page=22}}</ref> They believe that only their religion represents true Christianity, and that all other religions fail to meet all the requirements set by God and will be destroyed.<ref>{{cite book|title=What Does The Bible Really Teach?|page=145|chapter=15 Worship That God Approves}}</ref> Jehovah’s Witnesses are taught that it is vital to remain "separate from the world." Watch Tower publications define the "world" as "the mass of mankind apart from Jehovah’s approved servants" and teach that it is ruled by Satan and a place of danger and moral contamination.<ref>''Reasoning From the Scriptures'', Watch Tower Bible & Tract Society, 1989, pages 435-436.</ref><ref>"Live a Balanced, Simple Life", ''The Watchtower'', July 15, 1989, page 11.</ref><ref>{{cite book| last = Holden| first = Andrew| title = Jehovah's Witnesses - Portrait of a Contemporary Religious Movement| publisher = Routledge| year = 2002| page = 12| isbn = 0-414-26610-6}}</ref> Because of perceived dangers from "worldly" association,<ref>''Make Sure of All Things'', Watch Tower Bible & Tract Society, 1953, page 279, "Association in a social way with those outside the truth is dangerous."</ref> Witnesses are advised to minimize social contact with non-members to better maintain their own standards of morality.<ref name=holdensocial>{{cite book| last = Holden| first = Andrew| title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement| publisher = Routledge| year = 2002| pages = 109–112| isbn = 0-415-26610-6}}</ref><ref>{{cite book| last = Franz| first = Raymond| authorlink = Raymond Franz| title = In Search of Christian Freedom| publisher = Commentary Press| year = 2007| page = 409| isbn = 0-914675-17-6}}</ref><ref>"Train With Godly Devotion as Your Aim", ''The Watchtower'', August 15, 1985, page 19.</ref><ref>{{cite journal |date=15 July 1997 |title=Are You Pursuing Virtue? |journal=The Watchtower |page=19 |publisher=Jehovah's Witnesses}}</ref><ref>''Survival Into a New Earth'', Watch Tower Bible & Tract Society, 1984, page 168.</ref><ref>"“Each One Will Carry His Own Load”, ''The Watchtower'', March 15, 2006, page 23.</ref>

Jehovah's Witnesses believe their highest allegiance belongs to [[Kingdom of God|God's kingdom]], which is viewed as an actual government in heaven, with Christ as king. They remain politically neutral, do not seek public office and are discouraged from voting, though individual members may participate in uncontroversial community improvement issues.<ref>Questions From Readers, ''The Watchtower'', November 1, 1999, p. 28,"As to whether they will personally vote for someone running in an election, each one of Jehovah’s Witnesses makes a decision based on his Bible-trained conscience and an understanding of his responsibility to God and to the State.</ref><ref>''Pay Attention to Yourselves and to All the Flock'', page 140.</ref><ref>''What Does God Require?'', Watch Tower Bible & Tract Society, 1996, page 13.</ref><ref>Questions From Readers, ''The Watchtower'', March 1, 1983, p. 30</ref> They abstain from celebrating religious holidays and birthdays and reject many customs they believe have pagan origins. They do not work in industries associated with the military, do not serve in the armed services<ref>''Worship the Only True God'', Watch Tower Bible & Tract Society, 2002, p. 159.</ref> and refuse national military service, which in some countries may result in their arrest and imprisonment.<ref>[http://www.jw-media.org/kor/20071004.htm Korea government promises to adopt alternative service system for conscientious objectors]</ref> They do not salute or pledge allegiance to flags or sing national anthems or patriotic songs.<ref>''Education'', Watch Tower Bible & Tract Society, 2002, pp. 20-23</ref>

===Rejection of blood transfusions===
{{Main|Jehovah's Witnesses and blood transfusions}}
[[Image:Bloedafname Sanquin.jpg|thumb|right|Jehovah's Witnesses officially reject transfusions of whole [[wiktionary:allogeneic|allogeneic]] blood and some of its fractionated components.]]
Jehovah's Witnesses refuse [[blood transfusion]]s, which they consider a violation of God's law based on their interpretation of Acts 15:28, 29 and other scriptures.<ref>{{cite book|last=Penton|first=M.J.|title=Apocalypse Delayed|year=1997|page=i}}</ref><ref>''Reasoning From the Scriptures'', Watch Tower Bible & Tract Society, 1989, pages 70-75.</ref><ref>{{cite book | last = Holden | first = Andrew | title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement | publisher = Routledge | year = 2002 | page = 91 | isbn = 0415266092}}</ref> Since 1961 the acceptance of a blood transfusion has been grounds for expulsion from the religion.<ref>{{cite journal|journal=BMJ|title=Bioethical aspects of the recent changes in the policy of refusal of blood by Jehovah's Witnesses|url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1119307|date=January 6, 2001|pages=37–39|pmid=11141155|doi=10.1136/bmj.322.7277.37|author=Muramoto, O.|volume=322}}</ref><ref>''Jehovah's Witnesses - Proclaimers of God's Kingdom,'' Watch Tower Bible & Tract Society, 1993, page 183.</ref> Watch Tower literature directs Witnesses to refuse transfusions in all cases even if death may result.<ref>''United in Worship of the Only True God'', Watch Tower Bible & Tract Society, 1983, pages 158-160.</ref><ref>{{cite book|last=Bowman|first=R. M.|coauthors=Beisner, E. C. , Ehrenborg, T.|title=Jehovah's Witnesses|publisher=Zondervan|year=1995|page=13}}</ref><ref>{{cite book| last = Botting| first = Heather| coauthors = Gary Botting| title = The Orwellian World of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1984| pages = 29–30| isbn = 0-8020-6545-7}}</ref><ref>Alan Rogerson, ''Millions Now Living Will Never Die'', Constable, 1969, pages 186-187.</ref> Jehovah's Witnesses do accept non-blood alternatives,<ref>"How Blood Can Save Your Life," Watchtower Bible and Tract Society, pages 13-17.</ref> and other life-saving measures, in lieu of blood transfusions.

Jehovah's Witnesses do not accept [[Red blood cell|red cells]], [[White blood cell|white cells]], [[platelet]]s or [[Blood plasma|plasma]], though they may accept certain fractions made from these components at their own discretion.<ref>{{cite journal|date=June 15, 2000|title=Questions From Readers–Do Jehovah’s Witnesses accept any medical products derived from blood?|journal=The Watchtower|page=30}}</ref><ref>{{cite journal|author=Sniesinski et al.|journal=Anesthesia & Analgesia|title=Coagulopathy After Cardiopulmonary Bypass in Jehovah's Witness Patients: Management of Two Cases Using Fractionated Components and Factor VIIa|url=http://www.freeminds.org/doctrine/sniecinski_analgesia2.pdf|month=April | year=2007 | volume = 104 | page = 763 | doi = 10.1213/01.ane.0000250913.45299.f3+|format=PDF|accessdate=2008-12-30|doi_brokendate=2009-07-27}}</ref> The Watch Tower Society provides members with [[Power of Attorney]] documents to indicate which optional fractions they accept, with pre-formatted wording prohibiting major components.<ref>{{cite book|title=Durable Power of Attorney form|publisher=Watch Tower Society|date=January 2001|page=1}} Examples of permitted fractions are: [[Interferon]], [http://www.noblood.org/wiki/Immune_Serum_Globulins Immune Serum Globulins] and [[Factor VIII]]; preparations made from [[Hemoglobin]] such as [http://www.noblood.org/wiki/Polyheme PolyHeme] and [[Hemopure]]. Examples of permitted procedures involving the medical use of one's own blood include: [http://www.noblood.org/wiki/Intraoperative_blood_salvage Cell Salvage], [http://www.noblood.org/wiki/Acute_Normovolemic_Hemodilution Hemodilution], [[heart lung machine|Heart-Lung Machine]], [[Dialysis]], [http://www.noblood.org/wiki/Epidural_Blood_Patch Epidural Blood Patch], [[Plasmapheresis]], [http://www.noblood.org/wiki/Blood_cell_scintigraphy Labeling or Tagging of Blood] and [http://www.noblood.org/wiki/Platelet_Gel Platelet Gel] ([[Autologous]])</ref><ref>{{cite journal|date=November 2006|title=Our Kingdom Ministry|format=PDF|pages=5–6|url=http://www.aggelia.be/km_nov2006.pdf|accessdate=2009-06-21}}</ref> If a fraction "makes up a significant portion of that component" or "carries out the key function of a primary component", it may be objectionable to some, but is permissible.<ref>{{cite journal|date=August 2006|title=The Real Value of Blood|journal=Awake!|page=11}}</ref> Jehovah's Witnesses have established Hospital Liaison Committees as a cooperative arrangement between individual Jehovah's Witnesses and medical professionals and hospitals.<ref>{{cite journal |title=Jehovah's Witnesses and Medical Profession Cooperate |journal=The Awake |month=November 22 |year=2003 |url=http://www.watchtower.org/e/19931122/article_01.htm|accessdate=2009-10-24}}</ref><ref>[http://www.tulsaworld.com/news/article.aspx?articleID=070515_1_A9_hThef38217 Kim Archer, "Jehovah's Witness liaisons help surgeons adapt", ''Tulsa World'', May 15, 2007.]</ref> American medical ethicist Osamu Muramoto has claimed the committees can have the effect of putting pressure on Witness patients to refuse blood-based treatment, compromising patient-doctor confidentiality, and the right of patients to choose their own form of medical care.<ref>[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC479294/ O. Muramoto, "Bioethics of the refusal of blood by Jehovah's Witnesses: Part 3. A proposal for a don't-ask-don't-tell policy", ''Journal of Medical Ethics'', December 1999, pages 463-468.]</ref>

== Demographics ==
[[Image:JWStats.png|right|thumb|350px|Average Publishers, 1945–2005]]
{{Main|Demographics of Jehovah's Witnesses}}
Jehovah's Witnesses have an active presence in most countries, though they do not form a large part of the population of any country. As of August 2009, Jehovah's Witnesses have an average of 7 million "publishers", the term they use for members actively involved in preaching. In 2009, these reports indicated a total of over 1.5 billion hours spent in preaching and Bible study activity. Since the mid-1990s, the number of peak publishers has increased from 4.5 million to 7.3 million,<ref>{{cite book|title=Yearbook of Jehovah's Witnesses|publisher=Watch Tower Society|date=1996–2009}}</ref> though there has been a decline in growth rates, from over 8% per annum in the mid 1970s, to 5% per annum in the mid 1990s, to about 2%–3% per annum since 1999.<ref>{{cite web | author=Grundy, Paul | url=http://jwfacts.com/index_files/statistics.htm | title=Facts about truth and Jehovah's Witnesses}}</ref> The official published membership statistics only include those who have reported preaching activity, and do not include "inactive" and disfellowshipped members. Jehovah's Witnesses have the lowest retention rate of all religious traditions in the United States. A 2008 study in the United States reported that only about one-third who self-identified their upbringing as "Jehovah’s Witnesses" still identify themselves with the religion as adults. The convert retention rate among Jehovah's Witnesses however, is one of the highest, reaching into the 90th percentile, though only about half the number who self-identify as Jehovah's Witnesses in the study are actually considered "active" by the faith itself.<ref>{{cite journal | title=U.S. Religious Landscape Survey Religious Affiliation: Diverse and Dynamic | publisher=Pew Forum on Religion & Public Life | month=February | year=2008 | pages=9, 30}}</ref><ref>[http://www.thearda.com/Denoms/D_1101.asp The Association of Religion Data Archives]</ref>

==Main publications used==
{{Main|List of Jehovah's Witnesses publications}}
The Watch Tower Society engages in extensive publishing work, producing books, brochures, and other media. Its most widely distributed publications are:
* ''[[New World Translation of the Holy Scriptures]]'' (1961, revised 1984), a translation of the [[Bible]]. It uses the name ''Jehovah'', an English version of the Hebrew [[Tetragrammaton]], also replacing the Greek word for "Lord" 237 times in the New Testament. It is available in 83 languages.
* ''[[The Watchtower]]'', a bi-monthly 32-page magazine containing articles on Bible topics. A Public Edition is distributed in their public ministry, and a Study Edition is published for the Watchtower Study. It is available in 180 languages.
* ''[[Awake!]]'', a monthly 32-page general-interest magazine, usually including articles on science, nature, and geography, with a religious slant.
* ''[[What Does the Bible Really Teach?]]'' (2005), the textbook used to conduct Bible studies.<ref>{{cite journal|date=January 2006|title=The Bible Teach Book—Our Primary Bible Study Aid|journal=Our Kingdom Ministry|page=1}}</ref> It is available in 209 languages.
* ''Keep Yourselves in God's Love'' (2008), used for Bible studies with people who have completed ''What Does the Bible Really Teach?''

==Criticisms==

{{Main|Criticism of Jehovah's Witnesses}}
Jehovah's Witnesses have attracted criticism over issues surrounding their Bible translation, doctrines, their handling of sexual abuse cases and what is claimed to be coercion of members.
===Biblical criticisms===
The Watch Tower Society has been criticized for its refusal to reveal the names and academic credentials of the translators of its ''[[New World Translation of the Holy Scriptures|New World Translation]]'' of the Bible.<ref name="pentonbible">{{cite book|author=Penton, M. J.|title=Apocalypse Delayed|publisher=University of Toronto Press|edition=2nd|year=1997|pages=174–176}}</ref> The society has claimed members of the translation committee wished to remain anonymous in order to exalt only the name of God,<ref>"New World Translation of the Christian Greek Scriptures", ''The Watchtower'', September 15, 1950, page 320.</ref> while ''The Watchtower'' said the educational qualifications of the translators were unimportant and that "the translation itself testifies to their qualifications".<ref>Questions from readers, ''The Watchtower'', December 15, 1974, page 767.</ref> Former Governing Body member Raymond Franz has claimed that only one member of the translation committee had sufficient qualifications for the task.<ref name=fred56>{{cite book| last = Franz| first = Raymond| authorlink = Raymond Franz | title = Crisis of Conscience| publisher = Commentary Press| year = 2007| page = 56| isbn = 0-914675-23-0}}</ref>

Some Bible scholars have noted that the translation of certain texts may be biased in favor of certain Witness practices and doctrines;<ref name="pentonbible" /><ref>Samuel Haas,''Journal of Biblical Literature,'' Vol. 74, No. 4, (Dec. 1955), p. 283, “This work indicates a great deal of effort and thought as well as considerable scholarship, it is to be regretted that religious bias was allowed to colour many passages.”</ref><ref name=Ankerberg>See Ankerberg, John and John Weldon, 2003, ''The New World Translation of the Jehovah's Witnesses'', accessible [http://www.johnankerberg.org/Articles/ATRI-Bible-School/Fall-Bible-School/fall-bible-school-jw-new-world-translation.htm online]</ref><ref>Rhodes R, The Challenge of the Cults and New Religions, The Essential Guide to Their History, Their Doctrine, and Our Response, Zondervan, 2001, p. 94</ref><ref>Bruce M Metzger, "Jehovah's Witnesses and Jesus Christ," Theology Today, (April 1953 p. 74); see also Metzger, "The New World Translation of the Christian Greek Scriptures," The Bible Translator (July 1964)</ref> theologians have also criticized the translators' insertion of the name ''Jehovah'' 237 times in the New Testament in places where the term is not used in the extant Greek manuscripts.<ref>G. Hébert/eds., "Jehovah's Witnesses", ''The New Catholic Encyclopedia,'' Gale, 20052, Vol. 7, p. 751.</ref><ref>Metzger, Bruce M., The New World Translation of the Christian Greek Scriptures, The Bible Translator 15/3 (July 1964), pp. 150-153.</ref> Watch Tower publications have said the name was "restored" on a sound basis, particularly when New Testament writers used the Greek ''Kyrios'' (Lord) when quoting earlier Old Testament scriptures that contained the Tetragrammaton.<ref>"God’s Name and the New Testament", ''The Divine Name That Will Endure Forever'', Watch Tower Bible & Tract Society, 1984, pages 23, 27.</ref> Their view is endorsed by one Bible scholar, George Howard.<ref>{{cite journal | last name = Howard| first name = George| journal = Journal of Biblical Literature (Vol.96) | publisher = University of Georgia |year = 1977 | page = 63 | quote=Recent discoveries in Egypt and the Judean Desert allow us to see first hand the use of God’s name in pre-Christian times. These discoveries are significant for N[ew] T[estament] studies in that they form a literary analogy with the earliest Christian documents and may explain how NT authors used the divine name. In the following pages we will set forth a theory that the divine name, הוהי (and possibly abbreviations of it), was originally written in the NT quotations of and allusions to the O[ld] T[estament] and that in the course of time it was replaced mainly with the surrogate [abbreviation for Ky′ri·os, “Lord”]. This removal of the Tetragram[maton], in our view, created a confusion in the minds of early Gentile Christians about the relationship between the ‘Lord God’ and the ‘Lord Christ’ which is reflected in the MS tradition of the NT text itself.}}</ref>

The translation has also been criticized for favoring literalism over the poetic qualities of original texts.<ref>Rowley, H.H., How Not To Translate the Bible, The Expository Times, 1953; 65; 41</ref>

===Doctrinal criticisms===

Watch Tower publications have claimed that God has used Jehovah's Witnesses (and previously, the International Bible Students) as a prophet to declare God's will<ref>"They Shall Know That a Prophet Was Among Them", ''The Watchtower'', April 1, 1972, page 197-200.</ref><ref name=WT59>''The Watchtower'', Jan. 15, 1959, pp.39-41</ref><ref>"Messengers of Godly Peace Pronounced Happy", ''The Watchtower'', May 1, 1997, page 21</ref><ref>''Jehovah's Witnesses - Proclaimers of God's Kingdom'', Watch Tower Society, 1993, page 708.</ref> and has equipped them with "special ... advanced knowledge" about future world events.<ref>"Execution of the “Great Harlot” Nears", ''The Watchtower'', October 15, 1980, page 17.</ref> Jehovah's Witnesses' publications have made many predictions about world events they believe were prophesied in the Bible including the resurrection of Jewish [[patriarch]]s, establishment of Christ's millennial kingdom, the demise of the [[League of Nations]] and [[United Nations]], the destruction of "false religion" and the global political system and the violent death of most of the world's population.<ref name="WT59" /><ref>{{Cite book | last = Crompton | first = Robert | title = Counting the Days to Armageddon | publisher = James Clarke & Co | year = 1996 | location = Cambridge | pages = 9, 115 | isbn = 0227679393}}</ref> The failure of some of those events, particularly relating to 1914, 1925 and 1975, has led to the alteration or abandonment of some doctrines.<ref>''Jehovah's Witnesses - Proclaimers of God's Kingdom,'' Watch Tower Bible & Tract Society, 1993, pages 78, 632.</ref> Some former Jehovah's Witnesses have accused the religion of being a false prophet for making those predictions, particularly because of assertions in some cases that the predictions were beyond doubt or had been approved by God.<ref>Criticisms of statements, such as those found below, are found in a number of books including Penton, M. James (1997) ''Apocalypse Delayed'', University of Toronto Press; Franz, Raymond, ''In Search of Christian Freedom'' (2007) Commentary Press; Watters, Randall (2004) ''Thus Saith Jehovah's Witnesses'', Common Sense Publications; Gruss, Edmond (2001) ''Jehovah's Witnesses: Their Claims, Doctrinal Changes, and Prophetic Speculation. What Does the Record Show?'', Xulon Press; Reed, David A. (1990) ''Index of Watchtower Errors'', 1879 to 1989, Baker Books and at websites including [http://www.watchtowerinformationservice.org/index.php/watchtower_quotes/ Watchtower Information Service]; [http://www.quotes-watchtower.co.uk/ Quotes-Watchtower.co.uk]; [http://www.reexamine.org/quotes/ Reexamine.Quotes].</ref><ref>Waldeck, Val ''Jehovah's Witnesses: What do they believe?''. Pilgrim Publications SA. ISBN 1-920092-08-0.</ref><ref>Buttrey, John M (2004). ''Let No One Mislead You''. iUniverse. ISBN 0-595-30710-8.</ref> Watch Tower Society publications have stated that Christians should not question what God tells them through his organization.<ref>{{cite journal|journal=The Watchtower|date=15 July 1974|page =441|title=The Godly Qualities of Love and Hate}}</ref> Former Witness Raymond Franz stated that members of the religion are expected to place "unwavering trust" in the predictions of the Watch Tower Society<ref name="Raymond Franz 2007, page 174">Raymond Franz, ''Crisis of Conscience'', 2007, page 174.</ref> and face expulsion if they do not accept its teachings, including predictions that have subsequently been set aside.<ref name="orwell3"/><ref>{{cite book| last = Franz| first = Raymond| authorlink = Raymond Franz| title = In Search of Christian Freedom| publisher = Commentary Press| year = 2007| location = Atlanta| pages = 18–28| isbn = 0-914675-17-6}}</ref>

The Watch Tower Society rejects accusations that it is a false prophet.<ref name="ReferenceA">"Why So Many False Alarms?", ''Awake!'', March 22, 1993, pages 3-4, footnote.</ref> It says its explanations of Bible prophecy are not infallible<ref>''Revelation - It's Grand Climax'', Watch Tower Bible & Tract Society, 1988, page 9.</ref> and that its predictions were not claimed as "the words of Jehovah".<ref name="ReferenceA"/> It admits some of its expectations have needed adjustment because of its eagerness for God's Kingdom, but that those adjustments are no reason to "call into question the whole body of truth."<ref>"Allow No Place for the Devil!", ''The Watchtower'', March 15, 1986, page 19, "Some opposers claim that Jehovah’s Witnesses are false prophets. These opponents say that dates have been set, but nothing has happened. ... Yes, Jehovah’s people have had to revise expectations from time to time. Because of our eagerness, we have hoped for the new system earlier than Jehovah’s timetable has called for it. But we display our faith in God’s Word and its sure promises by declaring its message to others. Moreover, the need to revise our understanding somewhat does not make us false prophets or change the fact that we are living in 'the last days,' ... How foolish to take the view that expectations needing some adjustment should call into question the whole body of truth! The evidence is clear that Jehovah has used and is continuing to use his one organization."</ref>

===Social criticisms===
Watch Tower publications instruct members to demonstrate [[loyalty]] to God by being loyal and obedient to the organization,<ref>"Following Faithful Shepherds with Life in View", ''The Watchtower'', October 1, 1967, page 591, "Make haste to identify the visible theocratic organization of God that represents his king, Jesus Christ. It is essential for life. Doing so, be complete in accepting its every aspect ... in submitting to Jehovah’s visible theocratic organization, we must be in full and complete agreement with every feature of its apostolic procedure and requirements."</ref><ref>"Loyal to Christ and His Faithful Slave", ''The Watchtower'', April 1, 2007, page 24, "When we loyally submit to the direction of the faithful slave and its Governing Body, we are submitting to Christ, the slave’s Master."</ref> promising the benefits of strength and protection from Satan's [[temptation]]s.<ref>"Keep Safe as Part of God’s Organization", ''The Watchtower'', September 1, 1998, page 9.</ref><ref>"What Influences Decisions in Your Life?", ''The Watchtower'', March 15, 1969, pages 171, "Jehovah’s organization as directed by his “faithful and discreet slave” class should influence our every decision also."</ref> Frequent calls for loyalty to the Watch Tower Society, and the practice of shunning dissident members, have led critics to refer to the religion's leadership as [[autocratic]].<ref>{{cite book | last = Holden | first = Andrew | title = Jehovah's Witnesses: Portrait of a Contemporary Religious Movement | publisher = Routledge | year = 2002 | page = 22 | isbn = 0415266092}}</ref><ref>Alan Rogerson, ''Millions Now Living Will Never Die'', Constable, 1969, page 50.</ref> Former Witness Edmond Gruss and authors including [[Anthony A. Hoekema]], Ron Rhodes<ref>{{Cite book | last = Rhodes | first = Ron | title = The Challenge of the Cults and New Religions | publisher = Zondervan | year = 2001 | location = Grand Rapids, Michigan | pages = 77–103 | isbn = 0310232171}}</ref> and Alan W. Gomes<ref>{{Cite book| last = Gomes | first = Alan W. | title = Unmasking the Cults | publisher = Zondervan | year = 1995 | pages = 22, 23 | isbn = 0310704413}}</ref> call the Watch Tower organization a religious [[cult]]. Gruss bases his claim on the "adulation" of the organization, the "mindless acceptance" of directions by members and the Watch Tower Society's insistence that faith in the organization is necessary for salvation.<ref>{{cite book | last = Gruss | first = Edmond C.| title = The Four Presidents of the Watch Tower Society| publisher = Xulon Press | year = 2003 | pages = 49–66 | isbn =1594671313 }}</ref> Hoekema has identified teachings he claims are characteristic of religious cults.<ref>{{Cite book | last = Hoekema | first = Anthony A. | authorlink = Anthony A. Hoekema| title = The Four Major Cults | publisher = William B. Eerdmans | year = 1963 | location = Grand Rapids, Michigan | pages = 1–8,223–371, 373–388 | isbn = 0802831176}}</ref> Jehovah's Witnesses deny they are a cult,<ref>"Are Jehovah’s Witnesses a Cult?", ''The Watchtower'', February 15, 1994, pages 5-7</ref> stating that individuals need guidance from God, but need to do their own thinking.<ref>"Do Others Do Your Thinking?", ''Awake!'', August 22, 1978, page 4.</ref><ref>"Who Molds Your Thinking?", ''The Watchtower'', April 1, 1999, page 22, "You have free will. Exercising it, you can choose to respond to Jehovah’s molding influence or deliberately reject it. How much better to listen to Jehovah’s voice instead of arrogantly asserting, 'No one tells me what to do'!"</ref> Cult deprogrammer John Bowen Brown II<ref>{{Citation| first=John Bowen | last=Brown II| coauthors=| contribution=Cult Watchdog Organizations and Jehovah’s Witnesses| title=Twenty Years and More: Research into Minority Religions, New Religious Movements and 'the New Spirituality'| editor-first=| editor-last=| coeditors=| publisher=Center for Studies on New Religions| place=London School of Economics, London, UK| pages=| date=2008-04-16| year=2008| id= | contribution-url=http://www.cesnur.org/2008/london_brown.htm| format=| accessdate=2010-03-03 }}</ref> and [[Joel P. Engardio]], the producer of the documentary ''[[Knocking (documentary)|Knocking]]'', also reject the claims.<ref>{{cite web|url=http://www.pbs.org/independentlens/knocking/myths.html |title=Myths & Realities |accessdate=2010-03-03 |last= Engardio |first=Joel P. |date=2007-04-17 |work=PBS Independent Lens |publisher=Public Broadcasting Service }}</ref><ref>{{Citation| first=John B. | last=Brown II| coauthors=| contribution=Jehovah's Witnesses and the Anti-cult Movement: A Human Rights Perspective| title=Religious Movements, Globalization and Conflict: Transnational Perspectives| editor-first=| editor-last=| coeditors=| publisher=Center for Studies on New Religions| place=Palermo, Sicily| pages=| date=2005-06-02| year=2005| id= | contribution-url=| format=| accessdate=2010-03-02 }}</ref>

Watch Tower literature warns that "independent thinking", such as questioning the counsel it provides, is dangerous.<ref>"Exposing the Devil’s Subtle Designs" and "Armed for the Fight Against Wicked Spirits", ''The Watchtower'', January 15, 1983</ref><ref>"Serving Jehovah Shoulder to Shoulder", ''The Watchtower'', August 15, 1981, page 28.</ref><ref>"Jehovah’s Theocratic Organization Today", ''The Watchtower'', February 1, 1952, pages 79-81.</ref> The Watch Tower Society instructs members to not read criticism of the organization by apostates, or former members,<ref>"Do not be quickly shaken from your reason", ''The Watchtower'', March 15, 1986</ref><ref>"At which table are you feeding?" ''The Watchtower'', July 1, 1994</ref> or literature published by other religions.<ref>''The Watchtower'', May 1, 1984, page 31, ''Questions from Readers''</ref><ref>"Firmly uphold godly teaching," ''The Watchtower'', May 1, 2000, page 9.</ref><ref>"Limping upon two opinions", ''The Watchtower'', August 15, 1967, page 489.</ref><ref>"Should You Investigate Other Religions?", ''The Watchtower'', October 15, 2000, page 9, "It is one thing to inform yourself about the origins and beliefs of false religions but quite another to feed on them ... Having found this knowledge of God through the Bible and the Christian congregation and having seen how Jehovah blesses those who are guided by that knowledge, true Christians do not continue listening to false religious teachings."</ref> This has led some critics to accuse the Watch Tower Society of causing mental isolation with the intent of [[mind control]].<ref name=Franz12>R. Franz, "In Search if Christian Freedom", chapter 12</ref><ref>James A. Beverley, ''Crisis of Allegiance'', Welch Publishing Company, Burlington, Ontario, 1986, ISBN 0920413374, pages 25-26, 101.</ref><ref>Edmond C. Gruss, editor, ''The Four Presidents of the Watch Tower Society'', Xulon Press, 2003, ISBN 1594671311, page 111.</ref>

Watch Tower Society publications say that the [[Proselytism|preaching work]] is "a fundamental requirement of their faith", and an obligation for Jehovah's Witnesses.<ref>"Keep Watching the Ministry Which You Accepted in the Lord", ''The Watchtower'', January 15, 2008, page 5.</ref><ref>"Assume Your Christian Obligations", ''The Watchtower'', March 1, 1966, page 139, "It is Scripturally established that Christians are under many obligations, which include preaching the good news. These are proper burdens that the Christian must bear."</ref><ref>"Live are at stake!", ''Our Kingdom Ministry'', September 2000, "Additionally, The Watchtower often emphasizes our obligation to preach."</ref> Raymond Franz and others describe the Watch Tower Society's continual admonitions to preach door-to-door as [[Coercive persuasion|coercive pressure]].<ref name=Franz6>R. Franz, ''In Search of Christian Freedom'', chapter 6.</ref><ref>Edmond C. Gruss, editor, ''The Four Presidents of the Watch Tower Society'', Xulon Press, 2003, ISBN 1594671311, pages 68-72.</ref><ref>{{cite book| last = Penton| first = M. James|title = Apocalypse Delayed: The Story of Jehovah's Witnesses| publisher = University of Toronto Press| year = 1997| pages = 114–116| isbn = 0-8020-7973-3}}</ref>

Critics claim that Witness medical patients have been coerced to obey the religion's ban on [[blood transfusion]]s.<ref name=Vancouver/><ref name="pulsus.com"/><ref>[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1377601/ "Bioethics of the refusal of blood by Jehovah's Witnesses, part 2." ''Journal of Medical Ethics'', October 1998, pages 295-301.]</ref> American neurologist and medical ethicist Osamu Muramoto has claimed that Watch Tower Society literature uses [[exaggeration]] and [[emotionalism]] to create [[paranoia]] and distort the facts about transfusions.<ref>[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1377670/?tool=pmcentrez&page=1 Osamu Muramoto, "Bioethics of the refusal of blood by Jehovah's Witnesses, part 1", ''Journal of Medical Ethics'', August 1998, Vol 24, Issue 4, page 223-230.]</ref>

===Handling of sexual abuse allegations===
{{Main|Jehovah's Witnesses and child sex abuse}}

Critics, including the organization [[Silentlambs]], have accused Jehovah's Witnesses of employing organizational policies that make the reporting of [[sexual abuse]] difficult for members. Some victims of sexual abuse have asserted that they were ordered by local elders to maintain silence so as to avoid embarrassment to both the accused and the organization.<ref name="Another Church Sex Scandal">[http://www.cbsnews.com/stories/2003/04/29/eveningnews/main551557.shtml "Another Church Sex Scandal"] (April 29, 2003). ''CBS News''.</ref><ref>Cutrer, Corrie (March 5, 2001). [http://www.christianitytoday.com/ct/2001/004/11.23.html "Witness Leaders Accused of Shielding Molesters"], ''Christianity Today''.</ref>

By 1997, Jehovah's Witnesses' Office of Public Information publicized their policy<ref>{{cite web|url=http://www.jw-media.org/aboutjw/article23.htm |title=Jehovah’s Witnesses and Child Protection |accessdate=2010-03-13 |year=1997 |work=Jehovah’s Witnesses Official Media Web Site |publisher=Watch Tower Bible and Tract Society of Pennsylvania }} [http://www.google.com/search?q=%22they+are+expected+to+report+the+allegation+to+the+branch+office+of+Jehovah%27s+Witnesses+in+their+country%2C+if+local+privacy+laws+permit%22&hl=en&rlz=1B6_____enUS348US348&sa=X&ei=Hc6bS4H6FpX08QbPn4y2Ag&ved=0CCIQpwU&tbs=cdr%3A1%2Ccd_min%3A1%2F1%2F1990%2Ccd_max%3A1%2F1%2F2010&tbo=1 See to confirm date.]</ref> for elders to report allegations of child abuse to the authorities where required by law to do so, even if there was only one witness.<ref>{{cite web|url=http://www.unelueur.org/forthechildren-August-1-1995.htm |title=To all Bodies of Elders in the United States |accessdate=2010-03-13 |date=1995-08-01 |publisher=WTBS }}</ref><ref>{{cite book | last = n/a | first = | authorlink = Watch_Tower_Bible_and_Tract_Society | coauthors = | title = Pay Attention to Yourselves and to All the Flock | publisher = Watch Tower Bible and Tract Society of Pennsylvania | year = 1977 | location = Brooklyn, New York | pages = 138 | url = | doi = | id = | isbn = }}</ref> Any person known to have sexually abused a child is prohibited from holding any responsibility inside the organization.<ref>{{cite journal|title=Let Us ABHOR What Is Wicked|journal=The Watchtower|date=1997-01-01|first=|last=|coauthors=|volume=|issue=|pages=27–29|id= |url=http://www.watchtower.org/e/19970101/article_01.htm|accessdate=2010-03-13 }}</ref> Unless considered by the congregation elders to demonstrate repentance, such a person is typically disfellowshipped.<ref name="The Watchtower 1998, page 16"/> The Watch Tower Society describes child abuse as "abhorrent" and instructs elders to investigate all allegations of child abuse and take congregational action if there is sufficient evidence. If there is not sufficient evidence, elders are required to report the matter to authorities and to their local Watch Tower Society branch office. It says victims of abuse have the "absolute right" to report allegations to authorities.<ref>[http://www.jw-media.org/aboutjw/article23.htm "Jehovah's Witnesses and Child Protection" statement, Official Media Web Site].</ref>

==References==
{{reflist|3}}

==Further reading==

*''Apocalypse Delayed: The Story of Jehovah's Witnesses'' by [[James Penton|M. James Penton]]. Penton, professor emeritus of history at University of Lethbridge and a former member of the religion, examines the history of Jehovah's Witnesses, and their doctrines. Read selections from: [http://books.google.com/books?ie=UTF-8&hl=en&id=38SYXalMLeQC&pg=PA3&;lpg=PA3&dq=apocalypse+delayed&prev=http://books.google.com/books%3Fq%3Dapocalypse%2Bdelayed%26lr%3D&sig=McaOJ75X4EEbvJHEsbwk4dTYk8o Apocalypse Delayed: the Story of Jehovah's Witnesses] University of Toronto Press. ISBN 0-8020-7973-3 (Canada, 1998) (Google book search)
* ''Jehovah's Witnesses: Portrait of a Contemporary Religious Movement'' by Andrew Holden. An academic study on the sociological aspects of Jehovah's Witnesses phenomenon. Publisher: Routledge; 1st edition 2002, ISBN 978–0415266109. 224 pages.
* ''Jehovah's Witnesses—Proclaimers of God's Kingdom'' (1993) by [[Watch Tower Bible and Tract Society of Pennsylvania]]. Official history of the development of the beliefs, practices, and organisational structure of Jehovah's Witnesses. 750 pages.
* ''A People for His Name: A History of Jehovah's Witnesses and an Evaluation'' by Tony Wills, (2006) 2nd edition. (The first edition was published under the pseudonym Timothy White.) Explores the Witnesses' doctrinal growth and shifts and notes schisms from the main body. 300 pages. ISBN 978–1-4303–0100–4 [http://books.google.com/books?id=iTt2EphfPr8C&printsec=frontcover Selections from Google Books]
* ''Counting the Days to Armageddon'' by Robert Crompton (1996). A detailed examination of the development of Jehovah's Witnesses' eschatology. James Clarke & Co, Cambridge, ISBN 0227679393.
* ''Millions Now Living Will Never Die'' by Alan Rogerson. Detailed history of the Watch Tower movement, particularly its early years, a summary of Witness doctrines and the organizational and personal framework in which Witnesses conduct their lives. Constable & Co, London, 1969. SBN 094559406
*''State and Salvation'' by William Kaplan (1989). Documents the Witnesses' fight for civil rights in Canada and the US amid political persecution during World War II. University of Toronto Press, ISBN 0802058426.

==External links==
{{Commons category|Jehovah's Witnesses}}


===Official sites===
* [http://www.watchtower.org Jehovah's Witnesses: Watch Tower Society Official Web Site]
* [http://www.jw-media.org Jehovah's Witnesses: Office of Public Information and Archives]
* [http://www.jw.org Official Jehovah’s Witnesses website for distribution of publications and free MP3 & AAC downloads]

===Other sites===

*[http://www.bbc.co.uk/religion/religions/witnesses/ BBC Religion: Jehovah's Witnesses]
*[http://www.strictlygenteel.co.uk/index.html Strictly Genteel Theocratic Resources] – Scans of complete books and booklets from Russell's era to Knorr's.
*[http://www.knocking.org/ 'Knocking'] – A documentary promoting Jehovah's Witnesses. [http://www.youtube.com/watch?v=Oj4cS4n9ZkA Sample Trailer]

{{Christianityfooter}}

[[Category:Antitrinitarianism]]
[[Category:Jehovah's Witnesses| ]]
[[Category:Premillennialism]]
[[Category:Restorationism]]

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Earwig

2010-02-02T17:35:30Z

64.22.228.134: /* Behavior */

{{Otheruses}}
{{Taxobox
| name = Earwig
| fossil_range= {{fossilrange|208|0}} [[Late Triassic]] to Recent
| image = Earwig on white background.jpg
| image_width = 240px
| image_caption = Common earwig, ''[[Forficula auricularia]]''
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| subphylum = [[Hexapoda]]
| classis = [[Insect]]a
| ordo = '''Dermaptera'''
| ordo_authority = [[Charles De Geer|De Geer]], 1773
| subdivision_ranks = Suborders
| subdivision = [[Archidermaptera]] 
[[Arixeniina]] 
[[Forficulina]] 
[[Hemimerina]]
| synonyms =
*Euplecoptera
*Euplexoptera
*Forficulida
}}
'''Earwigs''', sometimes called '''pincerbugs''', make up the [[insect]] [[order (biology)|order]] '''Dermaptera'''. The order is relatively small among other insect orders, with only 1,800 recorded [[species]] in 12 [[family (biology)|families]], found through out the [[Americas]], [[Eurasia]] and [[Australia]]. Typical earwigs have characteristic [[cercus|cerci]], a pair of [[forceps]]-like pincers on their abdomen, and membranous [[insect wing|wings]] folded underneath short [[wikt:fore wing|forewings]], hence the literal translation of the scientific name for order "skin wings". Some groups within the earwig order are tiny parasites on mammals and lack the typical pincers. Earwigs can fly, but rarely do so.

Earwigs are [[nocturnality|nocturnal]]; they often hide in small, moist crevices during the day, and are active at night, feeding on a wide variety of other insects and plants. Damage to foliage, flowers, and various crops are commonly blamed on earwigs, especially the [[Forficula auricularia|common earwig]]. However, the harmfulness of earwigs to foliage is still under debate, as they also eat certain insects that damage them.

Earwigs undergo an average of 5 [[molt]]s over the course of a year, their average life expectancy, before they become adults. An uncommon behavior in other insects, many earwig species display maternal care. Female earwigs are known to take extreme care of their eggs, and even after they have hatched as [[nymph (biology)|nymphs]] will continue to watch over offspring until their second molt. As the nymphs molt, [[sexual dimorphism]] such as differences in pincer shapes begins to show.

Earwig fossils have been found dating back {{ma|208}}. Those specimens are now included in the extinct suborder [[Archidermaptera]] dating back to the [[Late Triassic]]. Many orders of insect have been theorized to be closely related to earwigs made by many authors, though [[Grylloblattaria]] is the most likely. The order of earwigs, Dermaptera, is still under dispute over its phylogenetic relations to other groups.

==Etymology==

The [[Biological classification|scientific name]] for the order, ''Dermaptera'', is [[Ancient Greek|Greek]] in origin, stemming from the words ''dermatos'', meaning skin, and ''pteron'', wing. It was coined by [[Charles De Geer]] in 1773. The common term, ''earwig'', is derived from the [[Old English language|Old English]] ''ēare'', which means "ear", and ''wicga'', which means "insect." The name may be related to the [[old wives' tale]] that earwigs burrowed into the brains of humans through the ear and therein laid their eggs.<ref>{{cite book|last=Friedrichsen|first=G W S |coauthors=Robert W Burchfield|title=The Oxford Dictionary of English Etymology|editor= Onions CT|publisher=Oxford University Press|location=United Kingdom, Oxford University|date=December 31, 1966|edition=1996 |pages=earwig|isbn=0198611129|url=http://www.amazon.com/Oxford-Dictionary-English-Etymology/dp/0198611129/ref=sr_1_1?ie=UTF8&s=books&qid=1258497364&sr=1-1}}</ref> Earwigs are predisposed to hiding in warm humid crevices and may indeed occasionally crawl into the human ear canal.<ref>{{cite journal|last=Fisher |first=JR |title=Earwig in the ear|journal=Western Journal of Medicine |date=1986|volume=145|issue=2|page=245|url= http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1306897/|pmid=3765607|pmc=1306897 }}</ref><ref name= "tolweb">{{Cite book|url=http://www.tolweb.org/Dermaptera|title=Dermaptera — Earwigs|author=Fabian Haas|publisher=Tree of Life web project}}</ref>

''Wicga'' is in turn related to ''wiggle'', and ultimately to other words implying movement, including ''way'' and ''vehicle'', all from [[Proto-Indo-European language|PIE]] ''wegh-''. Other languages have words based on the same premises: [[German language|German]] ''Ohrenkneifer'', ''Ohrwurm'', or ''Ohrenhöhler'';<ref name="German">Gundolf Keil: ''Die Bekämpfung des Ohrwurms nach Anweisungen spätmittelalterlicher und frühneuzeitlicher deutscher Arzneibücher'', Zeitschrift für deutsche Philologie 79 (1960), S. 176–200, {{ISSN|0044-2496}}</ref> [[Dutch language|Dutch]] ''oorwormen'' or ''oorwurmen'';<ref name="Dutch">{{cite book|title=De in Nederland voorkomende oorwormen (Dermaptera)|url=http://openlibrary.org/b/OL5264236M/in-Nederland-voorkomende-oorwormen-(Dermaptera)|last=Willemse|first=C.|year=1971|publisher=Koninklijke Nederlandse Natuurhistorische Vereniging|accessdate=2009-07-27}}</ref> [[French language|French]] ''perce-oreille'' (ear-piercer,<ref>{{cite book|last=Derrida|first=Jacques|others=Trans. Alan Bass|title=Margins of Philosophy|publisher=University of Chicago Press|location=Chicago|date=1982|page=xiii|isbn=0226143260}}</ref> literally pierce-ear<ref>{{cite journal|last=Savary|first=A|date=July 2008|title=Computational inflection of multi-word units: a contrastive study of lexical approaches|journal=Linguistic Issues in Language Technology|volume=1|issue=2|pages=1–53}}</ref>); [[Danish language|Danish]] ''ørentviste''; [[Slovak language|Slovak]] ''ucholak'' (''ucho'' = ear, ''lak'' = scare); [[Romanian language|Romanian]] ''urechelniță''; [[Bulgarian language|Bulgarian]] ''уxолазка'' (''уxо'' = ear, ''лазка'' = crawler(f.)); and [[Hungarian language|Hungarian]] ''fülbemászó'' ("crawler-into-the-ear"). English has derived a verb from this, ''to earwig'', meaning "to attempt to influence by persistent confidential argument or talk".<ref>{{cite book|others=Editors of the American Heritage Dictionaries|title=The American Heritage Dictionary of the English Language|publisher=Houghton Mifflin Harcourt|date=April 12, 2006|edition=Fourth|series=American Heritage Dictionary of the English Language Ser.|pages=earwig|isbn=0618701729|url=http://www.amazon.com/gp/product/0618701729}}</ref> The German word ''Ohrwurm'' has the derived meaning of [[earworm]].<ref name="Earworm">{{cite web|url=http://findarticles.com/p/articles/mi_m1510/is_n57/ai_6203181/pg_9/|title=Untranslatable words - contains list of words that defy translation| last=Rheingold|first=Howard|date=1987|publisher=FindArticles.com|work=Whole Earth Review|accessdate=2009-06-24}}</ref> Hungarian also uses the phrase ''fülbemászó dallam'', meaning "a catchy melody".<ref>{{cite web|url=http://szotar.sztaki.hu/dict_search.php?L=HUN%3AENG%3AEngHunDict&O=HUN&flash=&E=1&sid=37d055f3f11efd0a42486a163ee6d1a5&vk=&in_form=1&W=f%C3%BClbem%C3%A1sz%C3%B3&M=1&P=1&C=1&T=1|title=Fülbemászó|publisher=Online Hungarian-English Dictionary|language=Hungarian|accessdate=2009-11-19}}</ref>
Some dialects of [[Swedish language|Swedish]] have related names for the earwig, but standard Swedish, by contrast, uses the word ''tvestjärt'', which translates as "two-tail", not unlike the [[Geordie]] ''forkytail''.{{Citation needed|date=November 2009}}

==Characteristics==
[[File:Earwigmorph.jpg|thumb|350px|External morphology. Click on image for a larger view]]
Most earwigs are flattened (to fit inside tight crevices, such as under bark) with an elongated body generally ranging from 7 to 50 mm,<ref name="gillott">{{cite book |last=Gillott |first=Cedric |title=Entomology |publisher=Springer |location=Dordrecht |date=2005 |edition=3 |pages=175–179 |isbn=978-1-4020-3184-7}}</ref> though in some earwigs can grow larger, such as the [[Saint Helena earwig]], which reaches 80 mm long. Earwigs are characterized by the [[cercus|cerci]], or the pair of [[forceps]]-like pincers on their abdomen; male earwigs have a curved pair of pincers, while females have straight pincers. These pincers are used to capture prey, defend themselves and fold their wings under the short tegmina.<ref name="Evolution of the Insects "/> The [[Antenna (biology)|antenna]]e are thread-like with at least 10 segments or more.<ref name="International Wildlife">{{cite book|last=Burton|first=Maurice |title=International Wildlife Encyclopedia |publisher=Marshall Cavendish Inc|date=January 2001|edition=3|isbn=0761472665|url=http://books.google.com/books?id=0gsPc5lk7_UC&printsec=frontcover&source=gbs_navlinks_s#v=onepage&q=earwig&f=false}}</ref>{{rp|738–739}}

The forewing is a short oblong leathery plate used to cover the forewing like the [[Elytron|elytra]] of a beetle, rather than to fly. Most species have short and leather-like forewings with very thin hindwings, though species in the suborders [[Arixeniina]] and [[Hemimerina]] have no wings and are blind with filiform segmented cerci.<ref name="gillott"/><ref name="gullan">{{cite book|last=Gullan|first=P.J.|coauthors=P.S. Cranston|title=The Insects: An Outline of Entomology|publisher=Blackwell Publishing |location=Oxford|date=2005|edition=3|page=235|chapter=9 - Ground Dwelling Insects|isbn=1-4051-1113-5|url=http://books.google.com/books?id=ZZaVjVWUaXIC&printsec=frontcover&source=gbs_navlinks_s#v=onepage&q=earwig&f=false}}</ref><ref name="NC-IPM">{{cite web|url=http://ipm.ncsu.edu/AG268/html/earwigs.htm|title=Earwigs|work=North Carolina Integrated Pest Management Information|accessdate=2009-07-20}}</ref> The hindwing is a very thin membrane that expands like a fan, radiating from one point folded under the forewing. Even though most earwigs have wings and are capable of flight, they are rarely seen in flight. These wings are unique in venation and in the pattern of folding that requires the use of the cerci.<ref>{{cite journal|journal=Acta zoologica cracoviensia| volume= 46| pages=67–72| year=2003 | title=The evolution of wing folding and flight in the Dermaptera (Insecta)|author=Haas, Fabian|url=http://www.isez.pan.krakow.pl/journals/azc_i/pdf/46%28suppl%29/08.pdf|format=PDF}}</ref> The epizoic species, sometimes considered as ectoparasites, are wingless.<ref>{{cite book|last=Carpenter|first=George Herbert |title=Insects: their structure & life|publisher=J. M. & Co.|location=London|date=1899|pages=170–172|chapter=4|url=http://books.google.com/books?id=yxMXAAAAYAAJ&pg=PA170&dq=earwig+wings#v=onepage&q=earwig%20wings&f=false}}</ref><ref name="The other insect societies">{{cite book|last=T. Costa|first=James|others=Foreword by Bert Hölldobler and commentary by Edward O. Wilson|title=The other insect societies |publisher=Harvard University Press|location=Harvard University|date=May 2006|edition=1|pages=53–54|chapter=3|isbn=Harvard University Press|url=http://books.google.com/books?id=PYRFDrZs9QAC&pg=PA53&dq=Arixeniina#v=onepage&q=Arixeniina&f=false}}</ref>[[Image:Dermaptera ps1.jpg|thumb|right|200px|Earwig with wings extended]]

===Behavior===
Earwigs are mostly scavengers, but some are omnivorous or predatory.<ref name="International Wildlife"/>{{rp|739–740}} The abdomen of the earwig is flexible and muscular. It is capable of manoeuvring as well as opening and closing the forceps. The forceps are used for a variety of purposes. In some species, the forceps have been observed in use for holding [[prey]], and in [[copulation]]. The forceps tend to be more curved in males than in females.<ref name="Field Guide to Texas Insects">{{cite web|url=http://insects.tamu.edu/fieldguide/aimg31.html|title=Earwig|last=Drees|first=B.M.|coauthors=John Jackman,|date=1999|work=Field Guide to Texas Insects|publisher=Gulf Publishing Company|page=1|accessdate=2009-11-15|location=Houston, Texas}}</ref>

[[File:Forficula.auricularia.-.lindsey.jpg|thumb|left|''[[Forficula auricularia]]'' feeding on flowers.]]
The [[Forficula auricularia|common earwig]] is one of the few insects that actively hunt for food and are omnivorous, eating [[arthropod]]s, plants, and ripe fruit. To a large extent, this species is also a scavenger, feeding on decaying plant and animal matter including garbage if given the chance. Insects that have been seen caught include largely plant lice and even large insects with its pincers, such as [[blue bottle fly|bluebottle flies]].<ref name="CSU"/> Plants that they feed on typically include [[clover]], [[dahlia]]s, [[zinnia]]s, [[Buddleia|butterfly bush]], [[hollyhock]], [[lettuce]], [[cauliflower]], [[strawberry]], [[sunflowers]], [[celery]], [[peach]]es, [[plum]]s, [[grapes]], [[potato]]es, [[rose]]s, seedling [[bean]]s and [[beet]]s, and tender [[grass]] shoots and roots; they have also been known to eat [[maize|corn]] silk, damaging the corn.<ref name="Predator">{{cite journal|last=Weiss|first=Michael J.|coauthors=Garrick McDonald|date=1998|title=European earwig, ''Forficula auriculari'' L. (Dermaptera: Forficulidae), as a predator of the redlegged earth mite, ''Halotydeus destructor'' (Tucker) (Acarina: Penthaleidae)|journal=Australian Journal of Entomology|volume=37|pages=183–185|doi=10.1111/j.1440-6055.1998.tb01569.x}}</ref>

Species of the suborders [[Arixeniina]] and [[Hemimerina]] are generally considered epizoic, or living on the outside of other [[animal]]s, mainly mammals. In the [[Arixeniina]], family [[Arixeniidae]], species of the genus ''[[Arixenia]]'' are normally found deep in the skin folds and gular pouch of [[Hairless Bat|Malaysian hairless bulldog bat]]s (''Cheiromeles torquatus''), apparently feeding on bat's body or glandular secretions. On the other hand, species in the genus ''[[Xenarina]]'' (still of the suborder Arixeniina) are believed to feed on the guano and possibly the guanophilous arthropods in the bat's nest, where it has been found. [[Hemimerina]] includes ''[[Araeomerus]]'' found in the nest of [[Beamys|Long-tailed pouch rat]]s (''[[Beamys]]''), and ''[[Hemimerus]]'' which are found on Giant ''[[Cricetomys]]'' rats.<ref name="The other insect societies"/><ref>{{cite journal|title=A review of the parasitic earwigs|year=1974| author=Nakata, Satsuko & TC Maa|journal=Pacific Insects | volume=16|pages=307–374 | url=http://hbs.bishopmuseum.org/pi/pdf/16%282%29-307.pdf}}</ref>

Earwigs are generally [[nocturnality|nocturnal]], and typically spend the daytime hours hiding in small, dark, and often moist areas. They can usually be seen patrolling household walls and ceilings. Interaction with earwigs at this time results in a defensive free-fall to the ground followed by a scramble to a nearby cleft or crevice.<ref name="Field Guide to Texas Insects"/> During the summer, they can be found around damp areas such as near sinks and in bathrooms. Earwigs tend to gather in shady cracks or openings or anywhere that they can remain concealed during daylight hours. Some people erroneously believe that [http://www.localpestcontrolservices.com/pest_control_blog/category/pests/earwigs/ earwigs ]crawl into people's ears at night and make burrows. [http://www.localpestcontrolservices.com/pest_control_blog/category/pests/earwigs/ Earwigs] are harmless to people, other than the fact that they might pinch them. Picnic tables, compost and waste bins, patios, lawn furniture, window frames, or anything with minute spaces (even [[artichoke]] blossoms) can potentially harbor them.<ref>{{cite web|url=http://urbanext.illinois.edu/bugreview/earwigs.html|last=Grupp|first=Susan M. |coauthors=Philip L. Nixon|title=The Bug Review-Earwigs|publisher=Extension Entomologist, Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign|page=1|accessdate=2009-11-15}}</ref> The only insect predators that prey on the earwig are parasitic species of [[Tachinidae]], or tachinid flies, whose larvae are endoparasites of the earwig. The eggs and nymphs can also be cannibalized by other earwigs.<ref>{{cite web|url=http://edis.ifas.ufl.edu/IN245|title=EENY088/IN245: Ringlegged Earwig, Euborellia annulipes (Lucas) (Insecta: Dermaptera: Carcinophoridae) |last=Capinera|first=John L. |date=June 1999|publisher=Entomology and Nematology Department, Institute of Food and Agricultural Sciences, University of Florida|page=1|accessdate=2009-11-15}}</ref>

===Life cycle and reproduction===
[[File:Earwig life cycle 2.svg|thumb|right|275px|The life cycle and development of an earwig from egg to each [[instar]]]]
Earwig are [[hemimetabolous]], or undergo incomplete metamorphosis, meaning they develop in a series of 4 to 6 [[molt]]s. The developmental stages between molts are called [[instar]]s. Earwigs live for about a year, completing their life cycle, starting from the egg. Females will start mating in fall around September and can be found together in the fall and winter. The male and female will live in a chamber in debris, crevices, or soil 2.5 mm deep. After mating, the sperm may remain in the female for months before the eggs are fertilized. In late January to early March, the male will leave or be driven out by the female. Afterward, the female will begin to lay 20 to 80 pearly white eggs in 2 days. Some earwigs, those parasitic in the suborders [[Arixeniina]] and [[Hemimerina]], are [[viviparous]], or give birth to live young; they would be fed by a sort of [[placenta]].<ref name="International Wildlife"/>{{rp|739–740}}<ref name="gullan"/> When first laid, the eggs are white or cream-colored and oval-shaped, but right before hatching, they become kidney-shaped and brown.<ref name="Ohio">{{cite web|url=http://ohioline.osu.edu/hyg-fact/2000/2068.html|title=Earwigs, HYG-2068-94|work=Ohio State University|accessdate=2009-07-20}}</ref> Each egg is approximately {{convert|1|mm|in|2|abbr=on}} tall and {{convert|0.8|mm|in|2|abbr=on}} wide.<ref name="NC-IPM"/>

Earwigs are among the few non-social insects species that show maternal care. The mother will pay close attention to the needs of her eggs, such as warmth and protection, though studies have shown that the mother does not pay attention to the eggs as she collects them.<ref name="gullan"/> The mother has been shown to pick up wax balls by accident, but would eventually be rejected as they must not have the proper scent. The mother will also vigorously defend the eggs from predators, not eating unless an egg goes bad.<ref name="International Wildlife"/>{{rp|740}} Another distinct maternal care unique to earwigs is that she will continuously clean the [[Egg (biology)|egg]]s to protect them from [[fungus|fungi]]. The urge to clean the eggs will persist for days when the eggs, as seen in the studies, are removed; when the eggs were replaced after they hatched, the mother would continue the urge to clean and them up to 3 months.<ref name="gullan"/>

The eggs hatch within 7 days. The mother may also assist the nymphs in hatching. When the nymphs hatch, they eat the egg casing and continue to live with the mother. The nymphs look similar to their parents, only smaller, and will nest under their mother and she will continue to protect them until their second molt in about July. The nymphs feed on food [[trophallaxis|regurgitated]] by the mother,<ref>{{cite journal|title=Maternal Food Regurgitation to Nymphs in Earwigs (Forficula auricularia)|author=Staerkle M & M Koelliker |doi=10.1111/j.1439-0310.2008.01526.x|journal=Ethology|volume=114 |year=2008| pages=844–850| url=http://evolution.unibas.ch/koelliker/pdf/Staerkle_Ethology2008.pdf| format=PDF}}</ref> and on their own molts. If the mother dies before the nymphs are ready to leave, the nymphs may eat her.<ref name="International Wildlife"/>{{rp|740}}<ref>{{cite journal| title=Matriphagy in the hump earwig, Anechura harmandi (Dermaptera: Forficulidae), increases the survival rates of the offspring|author=Suzuki, S. Kitamura, M. Matsubayashi, K.|journal= Journal of Ethology| year=2005| volume =23| issue=2| pages=211–213| doi=10.1007/s10164-005-0145-7}}</ref>

After five to six [[instars]], the nymphs will molt into adults. The male's forceps will become curved, while the females' remain straight. They will also develop their natural color, which can be anything from a light brown (as in the [[Tawny earwig]]) to a dark black (as in the [[Ringlegged earwig]]). In species of winged earwigs, the wings will start to develop at this time. The hindwings of an earwig are made of [[Elytron|elytra]] the same material that beetles' shells are made of.<ref name="NC-IPM"/>

==Distribution==
[[Image:Earwig iruppu.jpg|thumb|200px|right|An earwig from the [[Western Ghats]]]]
Earwigs are fairly abundant and can be found virtually everywhere, especially throughout the [[Americas]] and [[Eurasia]]. The common earwig was introduced into North America in 1907 from [[Europe]] and now occur throughout North America, but tend to be more common in the southern and southwestern states.<ref name="International Wildlife"/>{{rp|739}} The only native species of earwig found in the north is the [[Doru aculeatum|Spine-tailed earwig]] (''Doru aculeatum'')<ref name="Robinson">{{cite book|last=Robinson|first=William H. |title=Handbook of urban insects and arachnids |publisher=Cambridge University Press|location=Cambridge, UK|date=2005|pages=480|isbn=9780521812535|url=http://www.cambridge.org/catalogue/catalogue.asp?isbn=0521812534}}</ref>{{rp|144}}, found as far north as [[Canada]], where it hides in the leaf axils of emerging plants in [[Ontario|southern Ontario]] [[wetland]]s. Though two to three other families can be found in North America, including [[Forficulidae]] (''[[Doru (genus)|Doru]]'' and ''[[Forficula]]'' being found there), [[Labiidae]], [[Carinophoridae]], and [[Labiduridae]].<ref name="Marshall">{{cite book|last=Marshall|first=Stephan A.|title=Insects: Their Natural History and Diversity: With a Photographic Guide to Insects of Eastern North America |publisher=Firefly Books|location=Buffalo, NY; Richmond Hill, Ontario|date=June 2006|pages=63–64|chapter=4|isbn=1552979008|url=http://www.amazon.com/Insects-Natural-History-Diversity-Photographic/dp/1552979008}}</ref>

Few earwigs survive winter outdoors in the northern [[United States]]. They can be found in tight crevices in woodland, fields and gardens.<ref name="International Wildlife"/>{{rp|739}}<ref name="CSU">{{cite web|url=http://www.ext.colostate.edu/Pubs/insect/05533.html|title=European Earwigs|last=Cranshaw|first=W.S.|date=1/07|work=5.533|publisher=Colorado State University|accessdate=2009-06-25}}</ref> Out of about 1,800 species, only about 25 occur in [[North America]], 45 in [[Europe]] (including 7 in [[Great Britain|Britain]]), and 60 in [[Australia]].<ref name="gillott"/>

==Evolution==
[[File:ArixeniaEsau.jpg|thumb|left|100px|''[[Arixenia esau]]'' from the suborder [[Arixeniina]]]]
[[File:HemimerusHanseni.jpg|thumb|left|65px|''[[Hemimerus hanseni]]'' from the suborder [[Hemimerina]]]]
The fossil record of the Dermaptera starts in the [[Late Triassic]] to [[Early Jurassic]] period about {{ma|208}} in [[England]] and [[Australia]], and comprises about 70 specimens in the extinct suborder [[Archidermaptera]]. Some of the traits believed by [[neontology|neontologists]] to belong to modern earwigs, are not found in the earliest fossils, but adults had five-segmented [[arthropod leg|tarsi]] (the final segment of the leg), well developed [[ovipositor]]s, veined tegmina (forewings) and long segmented [[cerci]], in fact the pincers would have not been curled and used as they are now.<ref name="Evolution of the Insects ">{{cite book|last=Grimaldi|first=David |coauthors=Michael Engel|title=Evolution of the Insects |publisher=Cambridge University Press|location=Cambridge University|date=May 2005|edition=1|series=Cambridge Evolution Ser.|pages=217–222|chapter=7|isbn=0521821495|url=http://books.google.com/books?id=Ql6Jl6wKb88C&pg=PA217&dq=earwig+evolution#v=onepage&q=earwig%20related&f=false|accessdate=2009-11-16}}</ref> The theorized stem group of the Dermaptera are the [[Protelytroptera]]. These insects, which resemble modern [[Blattodea]], or Cockroaches, are known from the [[Permian]] of North America, Europe and Australia. Owing to shell-like forewings and the large, unequal anal fan. There are no fossils from the Triassic when the morphological changes from Protelytroptera to Dermaptera took place.<ref name="tolweb"/> The most likely, and closest resembling, related order of insects is [[Grylloblattaria]], theorized by Giles in 1963. However, other arguments link them to [[Phasmida]], [[Embioptera]], [[Plecoptera]], and [[Dictyoptera]], which have been made by other authors.<ref name="gillott"/>

Archidermaptera is believed to be sister to the remaining earwig groups. This suborder has tarsi with five segments (unlike the three found in the other suborders) as well as unsegmented cerci like [[Hemimerina]] and [[Arixenina]], no fossil Hemimerina and Arixenina are known though.<ref name="Korean">{{cite journal|last=Engel|first=Michael A.|coauthors=Jong-Deock Lim, Kwang-Seok Baek, and Larry D. Martin|date=2002|title=An Earwig from the Lower Cretaceous of Korea (Dermaptera: Forficulina)|journal=Journal of the Kansas Entomological Society|volume=75|issue=2|pages=86–90}}</ref> Species in Hemimerina were at one time in their own order, Diploglassata, Dermodermaptera, or [[Hemimerina]]. Like most other epizoic species, there is no fossil record, but they are probably no older than [[Tertiary|late Tertiary]].<ref name="Evolution of the Insects "/>

Some evidence of early evolutionary history is the structure of the antennal heart, a separate [[circulatory system|circulatory organ]] consisting of two [[ampulla]]e, or vesicles,<ref name="Gordh">{{cite book|last=Gordh|first=George|coauthors=David H. Headrick|title=A Dictionary of Entomology|publisher=CABI Publishing|date=2003|isbn=0851996558|url=http://books.google.com/books?id=HxAIAAAACAAJ&dq=Dictionary+of+entomology}}</ref> that are attached to the frontal cuticle to the bases of the [[Antenna (biology)|antenna]]e.<ref name="Pass">{{cite journal|last=Pass|first=Günther|coauthors=Hans Agricola, Heiner Birkenbeil, and Heinz Penzlin|date=August, 1988|title=Morphology of neurones associated with the antennal heart of Periplaneta americana (Blattodea, Insecta) |journal=Cell and Tissue Research|publisher=Springer Berlin / Heidelberg|volume=253 |issue= 2 |pages=319–326|issn=0302-766X|url=http://www.springerlink.com/content/m122r284j5705341/|pmid=3409288}}</ref> These features have not been found in other insects. An independent organ exists for each antenna, consisting of an [[ampulla]], attached to the frontal cuticle medial to the antenna base and forming a thin-walled sac with a valved ostium on its ventral side. They pump blood, not by muscle, but by elastic connective tissue.<ref name="Earwig Circulatory System">{{cite book|last=Nation|first=James L. |publisher=CRC Press|date=November 28, 2001|edition=1 |pages=310|chapter=11: Circulatory System|isbn=0849311810|url=http://books.google.com/books?id=l3v2tOvz1uQC&printsec=frontcover&source=gbs_similarbooks_s&cad=1#v=onepage&q=earwigs&f=false|title=Insect physiology and biochemistry}}</ref>

==Taxonomy==
===Distinguishing characteristics===
The characteristics which distinguish the order Dermaptera from other insect orders are:<ref name="Gillot">Gillot, C. ''Entomology'' 2nd Ed. (1995) Springer, ISBN 0306449676, 9780306449673. Accessed on [http://books.google.co.in/books?id=DrTKxvZq_IcC&source=gbs_navlinks_s Google Books] on 25 Nov 2009.</ref>
*''General body shape'': Elongate; [[Anatomical_terms_of_location#Dorsal_and_ventral|dorso-ventrally]] flattened.
*''Head'': [[Prognathous]]. [[Antenna]]e are segmented. Biting-type [[mouthparts]]. [[Ocellus|Ocelli]] absent. Compound eyes in most species, reduced or absent in some taxa.
*''Appendages'': Two pairs of wings normally present. The forewings are modified into short smooth, veinless [[tegmen|tegmina]]. Hindwings are [[biological membrane|membranous]] and semicircular with [[Insect_wing#Veins|vein]]s radiating outwards.
*''Abdomen'': [[Cerci]] are unsegmented and resemble [[forcep]]s. The [[ovipositor]] in females is reduced or absent.

The overwhelming majority of earwig species are in Forficulina, grouped into nine families of 180 genera,<ref name="tolweb" /> including ''[[Forficula auricularia]]'', the common European Earwig. Species within Forficulina are free-living, have functional wings and are not parasites. The cerci are unsegmented and modified into large, forceps-like structures.

The first epizoic species of earwig was discovered by a [[London]] [[taxidermy|taxidermist]] on the body of a [[Cheiromeles torquatus|Malaysian hairless bulldog bat]] in 1909, then described by [[Karl Jordan]]. By the 1950s, the two suborders ''Arixeniina'' and ''Hemimerina'' had been added to Dermaptera.<ref name="The other insect societies "/>

Arixeniina represents two genera, [[Arixenia]] and [[Xeniaria]], with a total of five species in them. As with Hemimerina, they are blind and wingless, with filiform segmented cerci. Hemimerina are [[viviparous]] [[ectoparasites]], preferring the fur of African rodents in either ''[[Cricetomys]]'' or ''[[Beamys]]'' genera.<ref name="Korean" /> Hemimerina also has two genera, ''[[Hemimerus]]'' and ''[[Araeomerus]]'', with a total of 11 species.<ref name="Korean" />

===Phylogeny===
'''Dermaptera''' (= Euplecoptera, Euplexoptera, or Forficulida<ref name="gillott"/>) is relatively small compared to the other orders of [[Insecta]], with only about 1,800 species, 3 suborders and 11 families, not including the one extinct suborder '''[[Archidermaptera]]''' and its extinct family '''[[Protodiplatyidae]]'''. The [[Phylogenetics|phylogeny]] of the Dermaptera is still debated. The extant Dermaptera appear to be monophyletic and there is support for the monophyly of the families Forficulidae, Chelisochidae, Labiduridae and Anisolabididae, however suggests that Forficulina is [[paraphyletic]] through the exclusion of Hemimerina which should instead be nested within the Forficulina.<ref name="tolweb"/><ref>{{cite journal|url=http://www.earwigs-online.de/privat_FH/KJ_FH_MW_2005.pdf|title=A phylogeny of earwigs (Insecta: Dermaptera) based on molecular and morphological evidence: reconsidering the classification of Dermaptera|author=Jarvis, KJ; F Haas; MF Whiting|journal=Systematic Entomology |year=2004|volume= 30|pages=1–12}}</ref>

'''Suborder [[Archidermaptera]] †''' 
:[[Protodiplatyidae]]

'''Suborder [[Arixeniina]]'''
:[[Arixeniidae]]

'''Suborder [[Forficulina]]'''
:[[Anisolabididae]]
:[[Apachyidae]]
:[[Chelisochidae]]
:[[Diplatyidae]]
:[[Forficulidae]]
:[[Karschiellidae]]
:[[Labiduridae]]
:[[Labiidae]]
:[[Pygidicranidae]]

'''Suborder [[Hemimerina]]'''
:[[Hemimeridae]]

==Relationship to people==
[[Image:Forficula auricularia.jpg|thumb|right|200px|The common earwig]]
Earwigs are fairly abundant and found in many areas of the world. There is no evidence that they transmit diseases to humans or other animals. Their pincers are commonly believed to be dangerous, but cause little harm to humans.<ref>{{cite web|title=Introduction to Earwigs|last=Harris|first=Bronwyn|date=2006|publisher=Home Institute|page=1|accessdate=2009-11-15}}</ref> It is a common [[urban legend]] that earwigs crawl into the human ear and lay eggs in the brain.<ref name="Urban Legends Reference Pages">{{cite web|url=http://www.snopes.com/horrors/insects/bugear.asp|title=Bugs in the Ear|last=Mikkelson|first=Barbara |coauthors=David P. Mikkelson|date=1995|work=Urban Legends Reference Pages|publisher=Snopes.com|pages=1|accessdate=22 November 2009}}</ref><ref name="Urban legend: Earwig">{{cite book|last=Berenbaum|first=May R.|title=The Earwig's Tail: A Modern Bestiary of Multi-Legged Legends|publisher=Harvard University Press|location=Harvard University|date=September 2009|pages=9–14|chapter=The Brain Bring Earwig|isbn=0674035402|url=http://books.google.com/books?id=FOlpPl_15csC&pg=PA13&dq=earwig+myth#v=onepage&q=earwig%20myth&f=false|accessdate=2009-11-22}}</ref> Finding earwigs in the human ear is rare, as most species do not fly and prefer dark and damp areas (e.g., basements) rather than typical bedrooms.<ref name= "tolweb"/>

There is a debate whether earwigs are either harmful or beneficial to crops, as they eat both the insects eating the foliage (e.g., [[aphid]]s) and the foliage itself, though it would take a large population to do considerable damage. The [[Forficula auricularia|common earwig]] eats a wide variety of plants, and also a wide variety of foliage including the leaves and petals. They have been known to cause economic losses in fruit and vegetable crops. Some examples are the [[flower]]s, [[Hop (plant)|hop]]s, and [[maize|corn crop]]s in [[Germany]], and in the south of [[France]] it has been known feeding on [[peach]]es and [[apricot]]s. The earwigs would attack mature plants and make cup-shaped bite marks 3 mm to 11 mm in diameter.<ref>{{cite journal|last=Solomon|first=M.G.|date=March 1992|title=Exploitation of predators in UK fruit and hop culture|journal=Phytoparasitica|volume=20|issue=Supplement 1|pages=51S–56S|doi=10.1007/BF02980408}}</ref>

==References==
{{reflist|2}}

==External links==
{{sisterlinks|wikt=earwig|b=Dichotomous Key/Dermaptera|q=no|s=no|commons=Dermaptera|n=no|v=no|species=Dermaptera}}
* [http://www.ento.csiro.au/education/insects/dermaptera.html Dermaptera - Earwigs from CSIRO]
* [http://www.snopes.com/horrors/insects/bugear.htm Bugs in the Ear urban legend from Snopes]
* [http://www.whatsthatbug.com/category/earwigs/ Earwig Page from What's That Bug]
* [http://www.earwigs-online.de Earwig Research Center by Fabian Haas, Heilbronn]
* [http://www.bbc.co.uk/nature/wildfacts/factfiles/421.shtml BBC Science and Nature Wildfacts from BBC: Science & Nature]
*[http://entomology.ifas.ufl.edu/creatures/veg/ringlegged_earwig.htm ringlegged earwig] on the [[University of Florida|UF]] / [[Institute of Food and Agricultural Sciences|IFAS]] Featured Creatures web site
* Langston RL & JA Powell (1975) [http://essig.berkeley.edu/documents/cis/cis20.pdf The earwigs of California (Order Dermaptera)]. Bulletin of the California Insect Survey. 20
*[http://www.localpestcontrolservices.com/pest_control_blog/category/pests/earwigs/ Earwigs at Local Pest Control Services]

[[Category:Insects]]
[[Category:Earwigs| ]]

[[ca:Dermàpter]]
[[cs:Škvoři]]
[[da:Ørentvist]]
[[de:Ohrwürmer]]
[[es:Dermaptera]]
[[fa:گوش‌خیزک]]
[[fr:Dermaptera]]
[[fy:Earkrûper]]
[[ga:Gailseach]]
[[ko:집게벌레목]]
[[io:Forfikulo]]
[[is:Klaufhalar]]
[[it:Dermaptera]]
[[he:צבתנאים]]
[[la:Dermaptera]]
[[lt:Auslindos]]
[[hu:Fülbemászók]]
[[nl:Oorwormen]]
[[nds-nl:Gaffeltaand]]
[[ja:ハサミムシ]]
[[no:Saksedyr]]
[[nn:Saksedyr]]
[[pl:Skorki (owady)]]
[[pt:Dermaptera]]
[[ru:Кожистокрылые]]
[[simple:Earwig]]
[[sl:Strigalice]]
[[sr:Ухолаже]]
[[su:Cocopét]]
[[fi:Pihtihäntäiset]]
[[sv:Tvestjärtar]]
[[to:Mokohula]]
[[zh:蠼螋]]

Earwig

2010-02-02T17:32:58Z

64.22.228.134: /* Behavior */

{{Otheruses}}
{{Taxobox
| name = Earwig
| fossil_range= {{fossilrange|208|0}} [[Late Triassic]] to Recent
| image = Earwig on white background.jpg
| image_width = 240px
| image_caption = Common earwig, ''[[Forficula auricularia]]''
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| subphylum = [[Hexapoda]]
| classis = [[Insect]]a
| ordo = '''Dermaptera'''
| ordo_authority = [[Charles De Geer|De Geer]], 1773
| subdivision_ranks = Suborders
| subdivision = [[Archidermaptera]] 
[[Arixeniina]] 
[[Forficulina]] 
[[Hemimerina]]
| synonyms =
*Euplecoptera
*Euplexoptera
*Forficulida
}}
'''Earwigs''', sometimes called '''pincerbugs''', make up the [[insect]] [[order (biology)|order]] '''Dermaptera'''. The order is relatively small among other insect orders, with only 1,800 recorded [[species]] in 12 [[family (biology)|families]], found through out the [[Americas]], [[Eurasia]] and [[Australia]]. Typical earwigs have characteristic [[cercus|cerci]], a pair of [[forceps]]-like pincers on their abdomen, and membranous [[insect wing|wings]] folded underneath short [[wikt:fore wing|forewings]], hence the literal translation of the scientific name for order "skin wings". Some groups within the earwig order are tiny parasites on mammals and lack the typical pincers. Earwigs can fly, but rarely do so.

Earwigs are [[nocturnality|nocturnal]]; they often hide in small, moist crevices during the day, and are active at night, feeding on a wide variety of other insects and plants. Damage to foliage, flowers, and various crops are commonly blamed on earwigs, especially the [[Forficula auricularia|common earwig]]. However, the harmfulness of earwigs to foliage is still under debate, as they also eat certain insects that damage them.

Earwigs undergo an average of 5 [[molt]]s over the course of a year, their average life expectancy, before they become adults. An uncommon behavior in other insects, many earwig species display maternal care. Female earwigs are known to take extreme care of their eggs, and even after they have hatched as [[nymph (biology)|nymphs]] will continue to watch over offspring until their second molt. As the nymphs molt, [[sexual dimorphism]] such as differences in pincer shapes begins to show.

Earwig fossils have been found dating back {{ma|208}}. Those specimens are now included in the extinct suborder [[Archidermaptera]] dating back to the [[Late Triassic]]. Many orders of insect have been theorized to be closely related to earwigs made by many authors, though [[Grylloblattaria]] is the most likely. The order of earwigs, Dermaptera, is still under dispute over its phylogenetic relations to other groups.

==Etymology==

The [[Biological classification|scientific name]] for the order, ''Dermaptera'', is [[Ancient Greek|Greek]] in origin, stemming from the words ''dermatos'', meaning skin, and ''pteron'', wing. It was coined by [[Charles De Geer]] in 1773. The common term, ''earwig'', is derived from the [[Old English language|Old English]] ''ēare'', which means "ear", and ''wicga'', which means "insect." The name may be related to the [[old wives' tale]] that earwigs burrowed into the brains of humans through the ear and therein laid their eggs.<ref>{{cite book|last=Friedrichsen|first=G W S |coauthors=Robert W Burchfield|title=The Oxford Dictionary of English Etymology|editor= Onions CT|publisher=Oxford University Press|location=United Kingdom, Oxford University|date=December 31, 1966|edition=1996 |pages=earwig|isbn=0198611129|url=http://www.amazon.com/Oxford-Dictionary-English-Etymology/dp/0198611129/ref=sr_1_1?ie=UTF8&s=books&qid=1258497364&sr=1-1}}</ref> Earwigs are predisposed to hiding in warm humid crevices and may indeed occasionally crawl into the human ear canal.<ref>{{cite journal|last=Fisher |first=JR |title=Earwig in the ear|journal=Western Journal of Medicine |date=1986|volume=145|issue=2|page=245|url= http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1306897/|pmid=3765607|pmc=1306897 }}</ref><ref name= "tolweb">{{Cite book|url=http://www.tolweb.org/Dermaptera|title=Dermaptera — Earwigs|author=Fabian Haas|publisher=Tree of Life web project}}</ref>

''Wicga'' is in turn related to ''wiggle'', and ultimately to other words implying movement, including ''way'' and ''vehicle'', all from [[Proto-Indo-European language|PIE]] ''wegh-''. Other languages have words based on the same premises: [[German language|German]] ''Ohrenkneifer'', ''Ohrwurm'', or ''Ohrenhöhler'';<ref name="German">Gundolf Keil: ''Die Bekämpfung des Ohrwurms nach Anweisungen spätmittelalterlicher und frühneuzeitlicher deutscher Arzneibücher'', Zeitschrift für deutsche Philologie 79 (1960), S. 176–200, {{ISSN|0044-2496}}</ref> [[Dutch language|Dutch]] ''oorwormen'' or ''oorwurmen'';<ref name="Dutch">{{cite book|title=De in Nederland voorkomende oorwormen (Dermaptera)|url=http://openlibrary.org/b/OL5264236M/in-Nederland-voorkomende-oorwormen-(Dermaptera)|last=Willemse|first=C.|year=1971|publisher=Koninklijke Nederlandse Natuurhistorische Vereniging|accessdate=2009-07-27}}</ref> [[French language|French]] ''perce-oreille'' (ear-piercer,<ref>{{cite book|last=Derrida|first=Jacques|others=Trans. Alan Bass|title=Margins of Philosophy|publisher=University of Chicago Press|location=Chicago|date=1982|page=xiii|isbn=0226143260}}</ref> literally pierce-ear<ref>{{cite journal|last=Savary|first=A|date=July 2008|title=Computational inflection of multi-word units: a contrastive study of lexical approaches|journal=Linguistic Issues in Language Technology|volume=1|issue=2|pages=1–53}}</ref>); [[Danish language|Danish]] ''ørentviste''; [[Slovak language|Slovak]] ''ucholak'' (''ucho'' = ear, ''lak'' = scare); [[Romanian language|Romanian]] ''urechelniță''; [[Bulgarian language|Bulgarian]] ''уxолазка'' (''уxо'' = ear, ''лазка'' = crawler(f.)); and [[Hungarian language|Hungarian]] ''fülbemászó'' ("crawler-into-the-ear"). English has derived a verb from this, ''to earwig'', meaning "to attempt to influence by persistent confidential argument or talk".<ref>{{cite book|others=Editors of the American Heritage Dictionaries|title=The American Heritage Dictionary of the English Language|publisher=Houghton Mifflin Harcourt|date=April 12, 2006|edition=Fourth|series=American Heritage Dictionary of the English Language Ser.|pages=earwig|isbn=0618701729|url=http://www.amazon.com/gp/product/0618701729}}</ref> The German word ''Ohrwurm'' has the derived meaning of [[earworm]].<ref name="Earworm">{{cite web|url=http://findarticles.com/p/articles/mi_m1510/is_n57/ai_6203181/pg_9/|title=Untranslatable words - contains list of words that defy translation| last=Rheingold|first=Howard|date=1987|publisher=FindArticles.com|work=Whole Earth Review|accessdate=2009-06-24}}</ref> Hungarian also uses the phrase ''fülbemászó dallam'', meaning "a catchy melody".<ref>{{cite web|url=http://szotar.sztaki.hu/dict_search.php?L=HUN%3AENG%3AEngHunDict&O=HUN&flash=&E=1&sid=37d055f3f11efd0a42486a163ee6d1a5&vk=&in_form=1&W=f%C3%BClbem%C3%A1sz%C3%B3&M=1&P=1&C=1&T=1|title=Fülbemászó|publisher=Online Hungarian-English Dictionary|language=Hungarian|accessdate=2009-11-19}}</ref>
Some dialects of [[Swedish language|Swedish]] have related names for the earwig, but standard Swedish, by contrast, uses the word ''tvestjärt'', which translates as "two-tail", not unlike the [[Geordie]] ''forkytail''.{{Citation needed|date=November 2009}}

==Characteristics==
[[File:Earwigmorph.jpg|thumb|350px|External morphology. Click on image for a larger view]]
Most earwigs are flattened (to fit inside tight crevices, such as under bark) with an elongated body generally ranging from 7 to 50 mm,<ref name="gillott">{{cite book |last=Gillott |first=Cedric |title=Entomology |publisher=Springer |location=Dordrecht |date=2005 |edition=3 |pages=175–179 |isbn=978-1-4020-3184-7}}</ref> though in some earwigs can grow larger, such as the [[Saint Helena earwig]], which reaches 80 mm long. Earwigs are characterized by the [[cercus|cerci]], or the pair of [[forceps]]-like pincers on their abdomen; male earwigs have a curved pair of pincers, while females have straight pincers. These pincers are used to capture prey, defend themselves and fold their wings under the short tegmina.<ref name="Evolution of the Insects "/> The [[Antenna (biology)|antenna]]e are thread-like with at least 10 segments or more.<ref name="International Wildlife">{{cite book|last=Burton|first=Maurice |title=International Wildlife Encyclopedia |publisher=Marshall Cavendish Inc|date=January 2001|edition=3|isbn=0761472665|url=http://books.google.com/books?id=0gsPc5lk7_UC&printsec=frontcover&source=gbs_navlinks_s#v=onepage&q=earwig&f=false}}</ref>{{rp|738–739}}

The forewing is a short oblong leathery plate used to cover the forewing like the [[Elytron|elytra]] of a beetle, rather than to fly. Most species have short and leather-like forewings with very thin hindwings, though species in the suborders [[Arixeniina]] and [[Hemimerina]] have no wings and are blind with filiform segmented cerci.<ref name="gillott"/><ref name="gullan">{{cite book|last=Gullan|first=P.J.|coauthors=P.S. Cranston|title=The Insects: An Outline of Entomology|publisher=Blackwell Publishing |location=Oxford|date=2005|edition=3|page=235|chapter=9 - Ground Dwelling Insects|isbn=1-4051-1113-5|url=http://books.google.com/books?id=ZZaVjVWUaXIC&printsec=frontcover&source=gbs_navlinks_s#v=onepage&q=earwig&f=false}}</ref><ref name="NC-IPM">{{cite web|url=http://ipm.ncsu.edu/AG268/html/earwigs.htm|title=Earwigs|work=North Carolina Integrated Pest Management Information|accessdate=2009-07-20}}</ref> The hindwing is a very thin membrane that expands like a fan, radiating from one point folded under the forewing. Even though most earwigs have wings and are capable of flight, they are rarely seen in flight. These wings are unique in venation and in the pattern of folding that requires the use of the cerci.<ref>{{cite journal|journal=Acta zoologica cracoviensia| volume= 46| pages=67–72| year=2003 | title=The evolution of wing folding and flight in the Dermaptera (Insecta)|author=Haas, Fabian|url=http://www.isez.pan.krakow.pl/journals/azc_i/pdf/46%28suppl%29/08.pdf|format=PDF}}</ref> The epizoic species, sometimes considered as ectoparasites, are wingless.<ref>{{cite book|last=Carpenter|first=George Herbert |title=Insects: their structure & life|publisher=J. M. & Co.|location=London|date=1899|pages=170–172|chapter=4|url=http://books.google.com/books?id=yxMXAAAAYAAJ&pg=PA170&dq=earwig+wings#v=onepage&q=earwig%20wings&f=false}}</ref><ref name="The other insect societies">{{cite book|last=T. Costa|first=James|others=Foreword by Bert Hölldobler and commentary by Edward O. Wilson|title=The other insect societies |publisher=Harvard University Press|location=Harvard University|date=May 2006|edition=1|pages=53–54|chapter=3|isbn=Harvard University Press|url=http://books.google.com/books?id=PYRFDrZs9QAC&pg=PA53&dq=Arixeniina#v=onepage&q=Arixeniina&f=false}}</ref>[[Image:Dermaptera ps1.jpg|thumb|right|200px|Earwig with wings extended]]

===Behavior===
Earwigs are mostly scavengers, but some are omnivorous or predatory.<ref name="International Wildlife"/>{{rp|739–740}} The abdomen of the earwig is flexible and muscular. It is capable of manoeuvring as well as opening and closing the forceps. The forceps are used for a variety of purposes. In some species, the forceps have been observed in use for holding [[prey]], and in [[copulation]]. The forceps tend to be more curved in males than in females.<ref name="Field Guide to Texas Insects">{{cite web|url=http://insects.tamu.edu/fieldguide/aimg31.html|title=Earwig|last=Drees|first=B.M.|coauthors=John Jackman,|date=1999|work=Field Guide to Texas Insects|publisher=Gulf Publishing Company|page=1|accessdate=2009-11-15|location=Houston, Texas}}</ref>

[[File:Forficula.auricularia.-.lindsey.jpg|thumb|left|''[[Forficula auricularia]]'' feeding on flowers.]]
The [[Forficula auricularia|common earwig]] is one of the few insects that actively hunt for food and are omnivorous, eating [[arthropod]]s, plants, and ripe fruit. To a large extent, this species is also a scavenger, feeding on decaying plant and animal matter including garbage if given the chance. Insects that have been seen caught include largely plant lice and even large insects with its pincers, such as [[blue bottle fly|bluebottle flies]].<ref name="CSU"/> Plants that they feed on typically include [[clover]], [[dahlia]]s, [[zinnia]]s, [[Buddleia|butterfly bush]], [[hollyhock]], [[lettuce]], [[cauliflower]], [[strawberry]], [[sunflowers]], [[celery]], [[peach]]es, [[plum]]s, [[grapes]], [[potato]]es, [[rose]]s, seedling [[bean]]s and [[beet]]s, and tender [[grass]] shoots and roots; they have also been known to eat [[maize|corn]] silk, damaging the corn.<ref name="Predator">{{cite journal|last=Weiss|first=Michael J.|coauthors=Garrick McDonald|date=1998|title=European earwig, ''Forficula auriculari'' L. (Dermaptera: Forficulidae), as a predator of the redlegged earth mite, ''Halotydeus destructor'' (Tucker) (Acarina: Penthaleidae)|journal=Australian Journal of Entomology|volume=37|pages=183–185|doi=10.1111/j.1440-6055.1998.tb01569.x}}</ref>

Species of the suborders [[Arixeniina]] and [[Hemimerina]] are generally considered epizoic, or living on the outside of other [[animal]]s, mainly mammals. In the [[Arixeniina]], family [[Arixeniidae]], species of the genus ''[[Arixenia]]'' are normally found deep in the skin folds and gular pouch of [[Hairless Bat|Malaysian hairless bulldog bat]]s (''Cheiromeles torquatus''), apparently feeding on bat's body or glandular secretions. On the other hand, species in the genus ''[[Xenarina]]'' (still of the suborder Arixeniina) are believed to feed on the guano and possibly the guanophilous arthropods in the bat's nest, where it has been found. [[Hemimerina]] includes ''[[Araeomerus]]'' found in the nest of [[Beamys|Long-tailed pouch rat]]s (''[[Beamys]]''), and ''[[Hemimerus]]'' which are found on Giant ''[[Cricetomys]]'' rats.<ref name="The other insect societies"/><ref>{{cite journal|title=A review of the parasitic earwigs|year=1974| author=Nakata, Satsuko & TC Maa|journal=Pacific Insects | volume=16|pages=307–374 | url=http://hbs.bishopmuseum.org/pi/pdf/16%282%29-307.pdf}}</ref>

Earwigs are generally [[nocturnality|nocturnal]], and typically spend the daytime hours hiding in small, dark, and often moist areas. They can usually be seen patrolling household walls and ceilings. Interaction with earwigs at this time results in a defensive free-fall to the ground followed by a scramble to a nearby cleft or crevice.<ref name="Field Guide to Texas Insects"/> During the summer, they can be found around damp areas such as near sinks and in bathrooms. Earwigs tend to gather in shady cracks or openings or anywhere that they can remain concealed during daylight hours. It erroneously believed by some that [http://www.localpestcontrolservices.com/pest_control_blog/category/pests/earwigs/ earwigs ]crawl into people's ears at night and make burrows. [http://www.localpestcontrolservices.com/pest_control_blog/category/pests/earwigs/ Earwigs] are harmless to people, other than the fact that they might pinch them. Picnic tables, compost and waste bins, patios, lawn furniture, window frames, or anything with minute spaces (even [[artichoke]] blossoms) can potentially harbor them.<ref>{{cite web|url=http://urbanext.illinois.edu/bugreview/earwigs.html|last=Grupp|first=Susan M. |coauthors=Philip L. Nixon|title=The Bug Review-Earwigs|publisher=Extension Entomologist, Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign|page=1|accessdate=2009-11-15}}</ref> The only insect predators that prey on the earwig are parasitic species of [[Tachinidae]], or tachinid flies, whose larvae are endoparasites of the earwig. The eggs and nymphs can also be cannibalized by other earwigs.<ref>{{cite web|url=http://edis.ifas.ufl.edu/IN245|title=EENY088/IN245: Ringlegged Earwig, Euborellia annulipes (Lucas) (Insecta: Dermaptera: Carcinophoridae) |last=Capinera|first=John L. |date=June 1999|publisher=Entomology and Nematology Department, Institute of Food and Agricultural Sciences, University of Florida|page=1|accessdate=2009-11-15}}</ref>

===Life cycle and reproduction===
[[File:Earwig life cycle 2.svg|thumb|right|275px|The life cycle and development of an earwig from egg to each [[instar]]]]
Earwig are [[hemimetabolous]], or undergo incomplete metamorphosis, meaning they develop in a series of 4 to 6 [[molt]]s. The developmental stages between molts are called [[instar]]s. Earwigs live for about a year, completing their life cycle, starting from the egg. Females will start mating in fall around September and can be found together in the fall and winter. The male and female will live in a chamber in debris, crevices, or soil 2.5 mm deep. After mating, the sperm may remain in the female for months before the eggs are fertilized. In late January to early March, the male will leave or be driven out by the female. Afterward, the female will begin to lay 20 to 80 pearly white eggs in 2 days. Some earwigs, those parasitic in the suborders [[Arixeniina]] and [[Hemimerina]], are [[viviparous]], or give birth to live young; they would be fed by a sort of [[placenta]].<ref name="International Wildlife"/>{{rp|739–740}}<ref name="gullan"/> When first laid, the eggs are white or cream-colored and oval-shaped, but right before hatching, they become kidney-shaped and brown.<ref name="Ohio">{{cite web|url=http://ohioline.osu.edu/hyg-fact/2000/2068.html|title=Earwigs, HYG-2068-94|work=Ohio State University|accessdate=2009-07-20}}</ref> Each egg is approximately {{convert|1|mm|in|2|abbr=on}} tall and {{convert|0.8|mm|in|2|abbr=on}} wide.<ref name="NC-IPM"/>

Earwigs are among the few non-social insects species that show maternal care. The mother will pay close attention to the needs of her eggs, such as warmth and protection, though studies have shown that the mother does not pay attention to the eggs as she collects them.<ref name="gullan"/> The mother has been shown to pick up wax balls by accident, but would eventually be rejected as they must not have the proper scent. The mother will also vigorously defend the eggs from predators, not eating unless an egg goes bad.<ref name="International Wildlife"/>{{rp|740}} Another distinct maternal care unique to earwigs is that she will continuously clean the [[Egg (biology)|egg]]s to protect them from [[fungus|fungi]]. The urge to clean the eggs will persist for days when the eggs, as seen in the studies, are removed; when the eggs were replaced after they hatched, the mother would continue the urge to clean and them up to 3 months.<ref name="gullan"/>

The eggs hatch within 7 days. The mother may also assist the nymphs in hatching. When the nymphs hatch, they eat the egg casing and continue to live with the mother. The nymphs look similar to their parents, only smaller, and will nest under their mother and she will continue to protect them until their second molt in about July. The nymphs feed on food [[trophallaxis|regurgitated]] by the mother,<ref>{{cite journal|title=Maternal Food Regurgitation to Nymphs in Earwigs (Forficula auricularia)|author=Staerkle M & M Koelliker |doi=10.1111/j.1439-0310.2008.01526.x|journal=Ethology|volume=114 |year=2008| pages=844–850| url=http://evolution.unibas.ch/koelliker/pdf/Staerkle_Ethology2008.pdf| format=PDF}}</ref> and on their own molts. If the mother dies before the nymphs are ready to leave, the nymphs may eat her.<ref name="International Wildlife"/>{{rp|740}}<ref>{{cite journal| title=Matriphagy in the hump earwig, Anechura harmandi (Dermaptera: Forficulidae), increases the survival rates of the offspring|author=Suzuki, S. Kitamura, M. Matsubayashi, K.|journal= Journal of Ethology| year=2005| volume =23| issue=2| pages=211–213| doi=10.1007/s10164-005-0145-7}}</ref>

After five to six [[instars]], the nymphs will molt into adults. The male's forceps will become curved, while the females' remain straight. They will also develop their natural color, which can be anything from a light brown (as in the [[Tawny earwig]]) to a dark black (as in the [[Ringlegged earwig]]). In species of winged earwigs, the wings will start to develop at this time. The hindwings of an earwig are made of [[Elytron|elytra]] the same material that beetles' shells are made of.<ref name="NC-IPM"/>

==Distribution==
[[Image:Earwig iruppu.jpg|thumb|200px|right|An earwig from the [[Western Ghats]]]]
Earwigs are fairly abundant and can be found virtually everywhere, especially throughout the [[Americas]] and [[Eurasia]]. The common earwig was introduced into North America in 1907 from [[Europe]] and now occur throughout North America, but tend to be more common in the southern and southwestern states.<ref name="International Wildlife"/>{{rp|739}} The only native species of earwig found in the north is the [[Doru aculeatum|Spine-tailed earwig]] (''Doru aculeatum'')<ref name="Robinson">{{cite book|last=Robinson|first=William H. |title=Handbook of urban insects and arachnids |publisher=Cambridge University Press|location=Cambridge, UK|date=2005|pages=480|isbn=9780521812535|url=http://www.cambridge.org/catalogue/catalogue.asp?isbn=0521812534}}</ref>{{rp|144}}, found as far north as [[Canada]], where it hides in the leaf axils of emerging plants in [[Ontario|southern Ontario]] [[wetland]]s. Though two to three other families can be found in North America, including [[Forficulidae]] (''[[Doru (genus)|Doru]]'' and ''[[Forficula]]'' being found there), [[Labiidae]], [[Carinophoridae]], and [[Labiduridae]].<ref name="Marshall">{{cite book|last=Marshall|first=Stephan A.|title=Insects: Their Natural History and Diversity: With a Photographic Guide to Insects of Eastern North America |publisher=Firefly Books|location=Buffalo, NY; Richmond Hill, Ontario|date=June 2006|pages=63–64|chapter=4|isbn=1552979008|url=http://www.amazon.com/Insects-Natural-History-Diversity-Photographic/dp/1552979008}}</ref>

Few earwigs survive winter outdoors in the northern [[United States]]. They can be found in tight crevices in woodland, fields and gardens.<ref name="International Wildlife"/>{{rp|739}}<ref name="CSU">{{cite web|url=http://www.ext.colostate.edu/Pubs/insect/05533.html|title=European Earwigs|last=Cranshaw|first=W.S.|date=1/07|work=5.533|publisher=Colorado State University|accessdate=2009-06-25}}</ref> Out of about 1,800 species, only about 25 occur in [[North America]], 45 in [[Europe]] (including 7 in [[Great Britain|Britain]]), and 60 in [[Australia]].<ref name="gillott"/>

==Evolution==
[[File:ArixeniaEsau.jpg|thumb|left|100px|''[[Arixenia esau]]'' from the suborder [[Arixeniina]]]]
[[File:HemimerusHanseni.jpg|thumb|left|65px|''[[Hemimerus hanseni]]'' from the suborder [[Hemimerina]]]]
The fossil record of the Dermaptera starts in the [[Late Triassic]] to [[Early Jurassic]] period about {{ma|208}} in [[England]] and [[Australia]], and comprises about 70 specimens in the extinct suborder [[Archidermaptera]]. Some of the traits believed by [[neontology|neontologists]] to belong to modern earwigs, are not found in the earliest fossils, but adults had five-segmented [[arthropod leg|tarsi]] (the final segment of the leg), well developed [[ovipositor]]s, veined tegmina (forewings) and long segmented [[cerci]], in fact the pincers would have not been curled and used as they are now.<ref name="Evolution of the Insects ">{{cite book|last=Grimaldi|first=David |coauthors=Michael Engel|title=Evolution of the Insects |publisher=Cambridge University Press|location=Cambridge University|date=May 2005|edition=1|series=Cambridge Evolution Ser.|pages=217–222|chapter=7|isbn=0521821495|url=http://books.google.com/books?id=Ql6Jl6wKb88C&pg=PA217&dq=earwig+evolution#v=onepage&q=earwig%20related&f=false|accessdate=2009-11-16}}</ref> The theorized stem group of the Dermaptera are the [[Protelytroptera]]. These insects, which resemble modern [[Blattodea]], or Cockroaches, are known from the [[Permian]] of North America, Europe and Australia. Owing to shell-like forewings and the large, unequal anal fan. There are no fossils from the Triassic when the morphological changes from Protelytroptera to Dermaptera took place.<ref name="tolweb"/> The most likely, and closest resembling, related order of insects is [[Grylloblattaria]], theorized by Giles in 1963. However, other arguments link them to [[Phasmida]], [[Embioptera]], [[Plecoptera]], and [[Dictyoptera]], which have been made by other authors.<ref name="gillott"/>

Archidermaptera is believed to be sister to the remaining earwig groups. This suborder has tarsi with five segments (unlike the three found in the other suborders) as well as unsegmented cerci like [[Hemimerina]] and [[Arixenina]], no fossil Hemimerina and Arixenina are known though.<ref name="Korean">{{cite journal|last=Engel|first=Michael A.|coauthors=Jong-Deock Lim, Kwang-Seok Baek, and Larry D. Martin|date=2002|title=An Earwig from the Lower Cretaceous of Korea (Dermaptera: Forficulina)|journal=Journal of the Kansas Entomological Society|volume=75|issue=2|pages=86–90}}</ref> Species in Hemimerina were at one time in their own order, Diploglassata, Dermodermaptera, or [[Hemimerina]]. Like most other epizoic species, there is no fossil record, but they are probably no older than [[Tertiary|late Tertiary]].<ref name="Evolution of the Insects "/>

Some evidence of early evolutionary history is the structure of the antennal heart, a separate [[circulatory system|circulatory organ]] consisting of two [[ampulla]]e, or vesicles,<ref name="Gordh">{{cite book|last=Gordh|first=George|coauthors=David H. Headrick|title=A Dictionary of Entomology|publisher=CABI Publishing|date=2003|isbn=0851996558|url=http://books.google.com/books?id=HxAIAAAACAAJ&dq=Dictionary+of+entomology}}</ref> that are attached to the frontal cuticle to the bases of the [[Antenna (biology)|antenna]]e.<ref name="Pass">{{cite journal|last=Pass|first=Günther|coauthors=Hans Agricola, Heiner Birkenbeil, and Heinz Penzlin|date=August, 1988|title=Morphology of neurones associated with the antennal heart of Periplaneta americana (Blattodea, Insecta) |journal=Cell and Tissue Research|publisher=Springer Berlin / Heidelberg|volume=253 |issue= 2 |pages=319–326|issn=0302-766X|url=http://www.springerlink.com/content/m122r284j5705341/|pmid=3409288}}</ref> These features have not been found in other insects. An independent organ exists for each antenna, consisting of an [[ampulla]], attached to the frontal cuticle medial to the antenna base and forming a thin-walled sac with a valved ostium on its ventral side. They pump blood, not by muscle, but by elastic connective tissue.<ref name="Earwig Circulatory System">{{cite book|last=Nation|first=James L. |publisher=CRC Press|date=November 28, 2001|edition=1 |pages=310|chapter=11: Circulatory System|isbn=0849311810|url=http://books.google.com/books?id=l3v2tOvz1uQC&printsec=frontcover&source=gbs_similarbooks_s&cad=1#v=onepage&q=earwigs&f=false|title=Insect physiology and biochemistry}}</ref>

==Taxonomy==
===Distinguishing characteristics===
The characteristics which distinguish the order Dermaptera from other insect orders are:<ref name="Gillot">Gillot, C. ''Entomology'' 2nd Ed. (1995) Springer, ISBN 0306449676, 9780306449673. Accessed on [http://books.google.co.in/books?id=DrTKxvZq_IcC&source=gbs_navlinks_s Google Books] on 25 Nov 2009.</ref>
*''General body shape'': Elongate; [[Anatomical_terms_of_location#Dorsal_and_ventral|dorso-ventrally]] flattened.
*''Head'': [[Prognathous]]. [[Antenna]]e are segmented. Biting-type [[mouthparts]]. [[Ocellus|Ocelli]] absent. Compound eyes in most species, reduced or absent in some taxa.
*''Appendages'': Two pairs of wings normally present. The forewings are modified into short smooth, veinless [[tegmen|tegmina]]. Hindwings are [[biological membrane|membranous]] and semicircular with [[Insect_wing#Veins|vein]]s radiating outwards.
*''Abdomen'': [[Cerci]] are unsegmented and resemble [[forcep]]s. The [[ovipositor]] in females is reduced or absent.

The overwhelming majority of earwig species are in Forficulina, grouped into nine families of 180 genera,<ref name="tolweb" /> including ''[[Forficula auricularia]]'', the common European Earwig. Species within Forficulina are free-living, have functional wings and are not parasites. The cerci are unsegmented and modified into large, forceps-like structures.

The first epizoic species of earwig was discovered by a [[London]] [[taxidermy|taxidermist]] on the body of a [[Cheiromeles torquatus|Malaysian hairless bulldog bat]] in 1909, then described by [[Karl Jordan]]. By the 1950s, the two suborders ''Arixeniina'' and ''Hemimerina'' had been added to Dermaptera.<ref name="The other insect societies "/>

Arixeniina represents two genera, [[Arixenia]] and [[Xeniaria]], with a total of five species in them. As with Hemimerina, they are blind and wingless, with filiform segmented cerci. Hemimerina are [[viviparous]] [[ectoparasites]], preferring the fur of African rodents in either ''[[Cricetomys]]'' or ''[[Beamys]]'' genera.<ref name="Korean" /> Hemimerina also has two genera, ''[[Hemimerus]]'' and ''[[Araeomerus]]'', with a total of 11 species.<ref name="Korean" />

===Phylogeny===
'''Dermaptera''' (= Euplecoptera, Euplexoptera, or Forficulida<ref name="gillott"/>) is relatively small compared to the other orders of [[Insecta]], with only about 1,800 species, 3 suborders and 11 families, not including the one extinct suborder '''[[Archidermaptera]]''' and its extinct family '''[[Protodiplatyidae]]'''. The [[Phylogenetics|phylogeny]] of the Dermaptera is still debated. The extant Dermaptera appear to be monophyletic and there is support for the monophyly of the families Forficulidae, Chelisochidae, Labiduridae and Anisolabididae, however suggests that Forficulina is [[paraphyletic]] through the exclusion of Hemimerina which should instead be nested within the Forficulina.<ref name="tolweb"/><ref>{{cite journal|url=http://www.earwigs-online.de/privat_FH/KJ_FH_MW_2005.pdf|title=A phylogeny of earwigs (Insecta: Dermaptera) based on molecular and morphological evidence: reconsidering the classification of Dermaptera|author=Jarvis, KJ; F Haas; MF Whiting|journal=Systematic Entomology |year=2004|volume= 30|pages=1–12}}</ref>

'''Suborder [[Archidermaptera]] †''' 
:[[Protodiplatyidae]]

'''Suborder [[Arixeniina]]'''
:[[Arixeniidae]]

'''Suborder [[Forficulina]]'''
:[[Anisolabididae]]
:[[Apachyidae]]
:[[Chelisochidae]]
:[[Diplatyidae]]
:[[Forficulidae]]
:[[Karschiellidae]]
:[[Labiduridae]]
:[[Labiidae]]
:[[Pygidicranidae]]

'''Suborder [[Hemimerina]]'''
:[[Hemimeridae]]

==Relationship to people==
[[Image:Forficula auricularia.jpg|thumb|right|200px|The common earwig]]
Earwigs are fairly abundant and found in many areas of the world. There is no evidence that they transmit diseases to humans or other animals. Their pincers are commonly believed to be dangerous, but cause little harm to humans.<ref>{{cite web|title=Introduction to Earwigs|last=Harris|first=Bronwyn|date=2006|publisher=Home Institute|page=1|accessdate=2009-11-15}}</ref> It is a common [[urban legend]] that earwigs crawl into the human ear and lay eggs in the brain.<ref name="Urban Legends Reference Pages">{{cite web|url=http://www.snopes.com/horrors/insects/bugear.asp|title=Bugs in the Ear|last=Mikkelson|first=Barbara |coauthors=David P. Mikkelson|date=1995|work=Urban Legends Reference Pages|publisher=Snopes.com|pages=1|accessdate=22 November 2009}}</ref><ref name="Urban legend: Earwig">{{cite book|last=Berenbaum|first=May R.|title=The Earwig's Tail: A Modern Bestiary of Multi-Legged Legends|publisher=Harvard University Press|location=Harvard University|date=September 2009|pages=9–14|chapter=The Brain Bring Earwig|isbn=0674035402|url=http://books.google.com/books?id=FOlpPl_15csC&pg=PA13&dq=earwig+myth#v=onepage&q=earwig%20myth&f=false|accessdate=2009-11-22}}</ref> Finding earwigs in the human ear is rare, as most species do not fly and prefer dark and damp areas (e.g., basements) rather than typical bedrooms.<ref name= "tolweb"/>

There is a debate whether earwigs are either harmful or beneficial to crops, as they eat both the insects eating the foliage (e.g., [[aphid]]s) and the foliage itself, though it would take a large population to do considerable damage. The [[Forficula auricularia|common earwig]] eats a wide variety of plants, and also a wide variety of foliage including the leaves and petals. They have been known to cause economic losses in fruit and vegetable crops. Some examples are the [[flower]]s, [[Hop (plant)|hop]]s, and [[maize|corn crop]]s in [[Germany]], and in the south of [[France]] it has been known feeding on [[peach]]es and [[apricot]]s. The earwigs would attack mature plants and make cup-shaped bite marks 3 mm to 11 mm in diameter.<ref>{{cite journal|last=Solomon|first=M.G.|date=March 1992|title=Exploitation of predators in UK fruit and hop culture|journal=Phytoparasitica|volume=20|issue=Supplement 1|pages=51S–56S|doi=10.1007/BF02980408}}</ref>

==References==
{{reflist|2}}

==External links==
{{sisterlinks|wikt=earwig|b=Dichotomous Key/Dermaptera|q=no|s=no|commons=Dermaptera|n=no|v=no|species=Dermaptera}}
* [http://www.ento.csiro.au/education/insects/dermaptera.html Dermaptera - Earwigs from CSIRO]
* [http://www.snopes.com/horrors/insects/bugear.htm Bugs in the Ear urban legend from Snopes]
* [http://www.whatsthatbug.com/category/earwigs/ Earwig Page from What's That Bug]
* [http://www.earwigs-online.de Earwig Research Center by Fabian Haas, Heilbronn]
* [http://www.bbc.co.uk/nature/wildfacts/factfiles/421.shtml BBC Science and Nature Wildfacts from BBC: Science & Nature]
*[http://entomology.ifas.ufl.edu/creatures/veg/ringlegged_earwig.htm ringlegged earwig] on the [[University of Florida|UF]] / [[Institute of Food and Agricultural Sciences|IFAS]] Featured Creatures web site
* Langston RL & JA Powell (1975) [http://essig.berkeley.edu/documents/cis/cis20.pdf The earwigs of California (Order Dermaptera)]. Bulletin of the California Insect Survey. 20
*[http://www.localpestcontrolservices.com/pest_control_blog/category/pests/earwigs/ Earwigs at Local Pest Control Services]

[[Category:Insects]]
[[Category:Earwigs| ]]

[[ca:Dermàpter]]
[[cs:Škvoři]]
[[da:Ørentvist]]
[[de:Ohrwürmer]]
[[es:Dermaptera]]
[[fa:گوش‌خیزک]]
[[fr:Dermaptera]]
[[fy:Earkrûper]]
[[ga:Gailseach]]
[[ko:집게벌레목]]
[[io:Forfikulo]]
[[is:Klaufhalar]]
[[it:Dermaptera]]
[[he:צבתנאים]]
[[la:Dermaptera]]
[[lt:Auslindos]]
[[hu:Fülbemászók]]
[[nl:Oorwormen]]
[[nds-nl:Gaffeltaand]]
[[ja:ハサミムシ]]
[[no:Saksedyr]]
[[nn:Saksedyr]]
[[pl:Skorki (owady)]]
[[pt:Dermaptera]]
[[ru:Кожистокрылые]]
[[simple:Earwig]]
[[sl:Strigalice]]
[[sr:Ухолаже]]
[[su:Cocopét]]
[[fi:Pihtihäntäiset]]
[[sv:Tvestjärtar]]
[[to:Mokohula]]
[[zh:蠼螋]]

Virtual machine

2010-01-20T16:21:41Z

64.22.228.134: /* System virtual machines */

A '''virtual machine''' ('''VM''') is a [[software]] implementation of a machine (i.e. a [[computer]]) that executes programs like a physical machine.

==Definitions==

A virtual machine was originally defined by [[Popek and Goldberg virtualization requirements|Popek and Goldberg]] as "an efficient, isolated duplicate of a real machine". Current use includes virtual machines which have no direct correspondence to any real hardware.<ref name="Smith_Nair_05">{{cite journal
| last = Smith
| first = James E.
| authorlink =
| coauthors = Nair, Ravi
| title = The Architecture of Virtual Machines
| journal = Computer
| volume = 38
| issue = 5
| pages = 32–38
| publisher = IEEE Computer Society
| location =
| date =
| url =
| doi = 10.1109/MC.2005.173
| id =
| accessdate = | year = 2005
}}</ref>

Virtual machines are separated into two major categories, based on their use and degree of correspondence to any real machine. A '''system virtual machine''' provides a complete [[system platform]] which supports the execution of a complete [[operating system]] (OS). In contrast, a '''process virtual machine''' is designed to run a single [[computer program|program]], which means that it supports a single [[process (computing)|process]]. An essential characteristic of a virtual machine is that the software running inside is limited to the resources and abstractions provided by the virtual machine—it cannot break out of its virtual world.

'''Example''':
A program written in [[Java (programming language)|Java]] receives services from the [[Java Runtime Environment]] (JRE) software by issuing commands to, and receiving the expected results from, the Java software. By providing these services to the program, the Java software is acting as a "virtual machine", taking the place of the operating system or hardware for which the program would ordinarily be tailored.

===System virtual machines===
{{see also|Platform virtualization|Comparison of platform virtual machines}}

System virtual machines (sometimes called '''hardware virtual machines''') allow the sharing of the underlying physical machine resources between different virtual machines, each running its own operating system. The software layer providing the virtualization is called a '''virtual machine monitor''' or [[hypervisor]]. A hypervisor can run on bare hardware ('''Type 1''' or '''native''' VM) or on top of an operating system ('''Type 2''' or '''hosted''' VM).

The main advantages of system VMs are:
* multiple OS environments can co-exist on the same computer, in strong isolation from each other
* the virtual machine can provide an [[instruction set]] architecture (ISA) that is somewhat different from that of the real machine
* application provisioning, maintenance, high availability and disaster recovery<ref>http://www.vmware.com/solutions/business-critical-apps/</ref>
* a virtual machine is more efficient than a real machine because it accesses the hardware indirectly

Multiple VMs each running their own operating system (called '''guest operating system''') are frequently used in '''server consolidation''', where different services that used to run on individual machines in order to avoid interference are instead run in separate VMs on the same physical machine. This use is frequently called '''quality-of-service isolation''' (QoS isolation).

The desire to run multiple operating systems was the original motivation for virtual machines, as it allowed time-sharing a single computer between several single-tasking OSes. This technique requires a process to share the CPU resources between guest operating systems and [[memory virtualization]] to share the memory on the host.

The guest OSes do not have to be all the same, making it possible to run different OSes on the same computer (e.g., [[Microsoft Windows]] and [[Linux]], or older versions of an OS in order to support software that has not yet been ported to the latest version). The use of virtual machines to support different guest OSes is becoming popular in [[embedded systems]]; a typical use is to support a [[real-time operating system]] at the same time as a high-level OS such as Linux or Windows.

Another use is to [[Sandbox (software development)|sandbox]] an OS that is not trusted, possibly because it is a system under development. Virtual machines have other advantages for OS development, including better debugging access and faster reboots.<ref>http://www.vmwarez.com/2006/05/super-fast-server-reboots-another.html</ref>

Alternate techniques such as [[Solaris Zones]] provides a level of isolation within a ''single'' operating system. This does not have isolation as complete as a VM.

===Process virtual machines===

{{see also|Application virtualization|Run-time system|Comparison of application virtual machines}}

A process VM, sometimes called an '''application virtual machine''', runs as a normal application inside an OS and supports a single process. It is created when that process is started and destroyed when it exits. Its purpose is to provide a [[system platform|platform]]-independent programming environment that abstracts away details of the underlying hardware or operating system, and allows a program to execute in the same way on any platform.

A process VM provides a high-level abstraction — that of a [[high-level programming language]] (compared to the low-level ISA abstraction of the system VM). Process VMs are implemented using an [[Interpreter (computing)|interpreter]]; performance comparable to compiled programming languages is achieved by the use of [[just-in-time compilation]].

This type of VM has become popular with the [[Java (programming language)|Java programming language]], which is implemented using the [[Java virtual machine]]. Other examples include the [[Parrot virtual machine]], which serves as an [[abstraction layer]] for several interpreted languages, and the [[.NET Framework]], which runs on a VM called the [[Common Language Runtime]].

A special case of process VMs are systems that abstract over the communication mechanisms of a (potentially heterogeneous) [[computer cluster]]. Such a VM does not consist of a single process, but one process per physical machine in the cluster. They are designed to ease the task of programming parallel applications by letting the programmer focus on algorithms rather than the communication mechanisms provided by the interconnect and the OS. They do not hide the fact that communication takes place, and as such do not attempt to present the cluster as a single parallel machine.

Unlike other process VMs, these systems do not provide a specific programming language, but are embedded in an existing language; typically such a system provides bindings for several languages (e.g., [[C (programming language)|C]] and [[FORTRAN]]). Examples are PVM ([[Parallel Virtual Machine]]) and MPI ([[Message Passing Interface]]). They are not strictly virtual machines, as the applications running on top still have access to all OS services, and are therefore not confined to the system model provided by the "VM".

==Techniques==
===Emulation of the underlying raw hardware (native execution) ===
This approach is described as [[full virtualization]] of the hardware, and can be implemented using a Type 1 or Type 2 [[hypervisor]]. (A Type 1 hypervisor runs directly on the hardware; a Type 2 hypervisor runs on another operating system, such as [[Linux]]). Each virtual machine can run any operating system supported by the underlying hardware. Users can thus run two or more different "guest" operating systems simultaneously, in separate "private" virtual computers.

The pioneer system using this concept was IBM's [[IBM CP-40|CP-40]], the first (1967) version of IBM's [[CP/CMS]] (1967-1972) and the precursor to IBM's [[VM (operating system)|VM family]] (1972-present). With the VM architecture, most users run a relatively simple [[interactive computing]] single-user operating system, [[Conversational Monitor System|CMS]], as a "guest" on top of the VM control program ([[VM-CP]]). This approach kept the CMS design simple, as if it were running alone; the control program quietly provides multitasking and resource management services "behind the scenes". In addition to CMS, VM users can run any of the other IBM operating systems, such as [[MVS]] or [[z/OS]]. [[z/VM]] is the current version of VM, and is used to support hundreds or thousands of virtual machines on a given mainframe. Some installations use [[Linux for zSeries]] to run [[Web server]]s, where [[Linux]] runs as the operating system within many virtual machines.

Full virtualization is particularly helpful in operating system development, when experimental new code can be run at the same time as older, more stable, versions, each in a separate virtual machine. The process can even be [[Recursion#Recursion in computing|recursive]]: [[IBM]] debugged new versions of its virtual machine operating system, [[VM (operating system)|VM]], in a virtual machine running under an older version of VM, and even used this technique to simulate new hardware.<ref>See [[History of CP/CMS]] for IBM's use of virtual machines for operating system development and simulation of new hardware</ref>

The standard [[x86]] [[processor architecture]] as used in modern PCs does not actually meet the [[Popek and Goldberg virtualization requirements]]. Notably, there is no execution mode where all sensitive machine instructions always trap, which would allow per-instruction virtualization.

Despite these limitations, several software packages have managed to provide [[x86 virtualization|virtualization on the x86 architecture]], even though [[dynamic recompilation]] of privileged code, as first implemented by [[VMware]], incurs some performance overhead as compared to a VM running on a natively virtualizable architecture such as the IBM System/370 or [[Motorola 68020|Motorola MC68020]]. By now, several other software packages such as [[Virtual PC]], [[VirtualBox]], [[Parallels Workstation]] and [[Virtual Iron]] manage to implement virtualization on x86 hardware.

[[Intel]] and [[AMD]] have introduced features to their x86 processors to enable virtualization in hardware.

===Emulation of a non-native system===
Virtual machines can also perform the role of an [[emulator]], allowing software applications and [[operating systems]] written for another [[computer processor]] architecture to be run.

Some virtual machines emulate hardware that only exists as a detailed specification. For example:

* One of the first was the [[p-code machine]] specification, which allowed programmers to write [[Pascal programming language|Pascal]] [[Computer program|programs]] that would run on any computer running virtual machine software that correctly implemented the specification.
* The specification of the [[Java virtual machine]].
* The [[Common Language Infrastructure]] virtual machine at the heart of the [[.NET Framework|Microsoft .NET]] initiative.
* [[Open Firmware]] allows plug-in hardware to include boot-time diagnostics, configuration code, and device drivers that will run on any kind of CPU.

This technique allows diverse computers to run any software written to that specification; only the virtual machine software itself must be written separately for each type of computer on which it runs.

===Operating system-level virtualization===

''[[Operating System-level Virtualization]]'' is a server [[Platform virtualization|virtualization]] technology which virtualizes [[Server (computing)|server]]s on an [[operating system]] (kernel) layer. It can be thought of as partitioning: a single physical server is sliced into multiple small partitions (otherwise called virtual environments (VE), [[virtual private server]]s (VPS), guests, zones, etc.); each such partition looks and feels like a real server, from the point of view of its users.

For example, Solaris Zones supports multiple guest OSes running under the same OS (such as Solaris 10). All guest OSes have to use the same kernel level and cannot run as different OS versions. Solaris native Zones also requires that the host OS be a version of Solaris; other OSes from other manufacturers are not supported.{{Fact|date=September 2008}},however you need to use Solaris Branded zones to use another OSes as zones.

Another example is [[Workload_partitions#System_WPAR|System Workload Partitions]] (WPARs), introduced in the IBM AIX 6.1 operating system. System WPARs are software partitions running under one instance of the global AIX OS environment.

The operating system level architecture has low overhead that helps to maximize efficient use of server resources. The virtualization introduces only a negligible overhead and allows running hundreds of [[virtual private server]]s on a single physical server. In contrast, approaches such as [[full virtualization]] (like [[VMware]]) and [[paravirtualization]] (like [[Xen]] or [[User-mode Linux|UML]]) cannot achieve such level of density, due to overhead of running multiple kernels. From the other side, operating system-level virtualization does not allow running different operating systems (i.e. different kernels), although different libraries, distributions etc. are possible.

{{main|operating system-level virtualization}}

==List of hardware with virtual machine support==

* [[Alcatel-Lucent]] [[3B21D|3B20D/3B21D]] emulated on [[commercial off-the-shelf]] computers with '''3B2OE''' or '''3B21E''' system
* [[AMD-V]] (formerly code-named Pacifica)
* [[ARM architecture|ARM TrustZone]]
* Boston Circuits gCore (grid-on-chip) with 16 [[ARC International|ARC]] 750D cores and Time-machine hardware virtualization module.
* [[Freescale]] [[PowerPC]] MPC8572 and MPC8641D
* [[IBM]] [[System/370]], [[System/390]], and [[zSeries]] mainframes
* [[Intel VT]] (formerly code-named Vanderpool)
* [[Sun Microsystems]] sun4v (UltraSPARC [[UltraSPARC T1|T1]] and [[UltraSPARC T2|T2]]) -- utilized by [[Logical Domains]]
{{seealso|x86 virtualization#Hardware support}}
* [[HP]] vPAR and cell based [[HP nPar (Hard Partitioning)|nPAR]]
* [[GE]] Project MAC then
* [[Honeywell]] Multics systems
* [[Honeywell]] 200/2000 systems Liberator replacing IBM 14xx systems, Level 62/64/66 GCOS
* [[IBM]] System/360 Model 145 Hardware emulator for Honeywell 200/2000 systems
* [[RCA]] Spectra/70 Series emulated IBM System/360
* [[NAS]] CPUs emulated IBM and Amdahl machines
* [[Honeywell]] Level 6 minicomputers emulated predecessor 316/516/716 minis
* [[Xerox]] Sigma 6 CPUs were modified to emulate GE/Honeywell 600/6000 systems

==List of virtual machine software==
{{external links}}
{{col-begin}}
{{col-2}}
;Process (Application) virtual machine software
* [[Baan]] Bshell Virtual Machine - Baan 4GL
* [[Common Language Infrastructure]] - [[C Sharp (programming language)|C#]], [[Visual Basic .NET]], [[J Sharp|J#]], [[C++/CLI]] (formerly [[Managed Extensions for C++|Managed C++]])
* [[Dalvik virtual machine]] - part of the [[Android mobile phone platform]]
* [http://doc.cat-v.org/inferno/4th_edition/dis_VM_design Dis] - [[Inferno operating system]] and its [[Limbo programming language]]
* [[Dosbox]]
* [[EiffelStudio]] for the [[Eiffel (programming language)|Eiffel programming language]]
* [[Erlang programming language]]
* [[Forth virtual machine]] - [[Forth (programming language)|Forth]]
* [[Glulx]] - [[Glulx]], [[Z-machine|Z-code]]
* Hec - [[Bytecode|Hasm Assembler]]
* [[Java Virtual Machine]] - [[Java (programming language)|Java]], [[Nice programming language|Nice]], [[REXX|NetREXX]]
* [[Juke Virtual Machine]] - A public domain ECMA-335 compatible virtual machine hosted at Google code.
* [[LLVM|Low Level Virtual Machine (LLVM)]] - currently [[C (programming language)|C]], [[C++]], Stacker
* [[Lua programming language|Lua]]
* [[Macromedia Flash Player]] - [[SWF]]
* Memory Array Redcode Simulator (MARS) - Virtual machine that executes [[Corewars]] programs.
* [[MMIX]] - [[MMIX]]AL
* Neko virtual machine - currently Neko and [[haXe]]
* [[O-code machine]] - [[BCPL]]
* [[p-code machine]] - [[Pascal programming language|Pascal]]
* [[Parrot virtual machine|Parrot]] - [[Perl 6]]
* [[Perl|Perl virtual machine]] - [[Perl]]
* [[CPython]] - [[Python (programming language)|Python]]
* [[YARV]] - [[Ruby MRI]]
* [[Rubinius]] - [[Ruby (programming language)|Ruby]]
* [[ScummVM]] - [[Scumm]]
* [[SECD machine]] - [[ISWIM]], [[Lispkit Lisp]]
* [[Sed]] the stream-editor can also be seen as a VM with 2 storage spaces.
* [[Smalltalk|Smalltalk virtual machine]] - [[Smalltalk]]
* [[SQLite|SQLite virtual machine]] - [[SQLite|SQLite opcodes]]
* [[Squeak|Squeak virtual machine]] - [[Squeak]]
* [[SWEET16]]
* [[Tamarin (JavaScript engine)]] - ActionScript VM in Flash 9
* [[TrueType|TrueType virtual machine]] - [[TrueType]]
* [[Valgrind]] - checking of memory accesses and leaks in [[x86]]/[[x86-64]] code under [[Linux]]
* [[Virtual Processor]] (VP) from [[Tao Group]] ([[United Kingdom|UK]]).
* [[VX32|VX32 virtual machine]] - application-level virtualization for native code
* Waba - Virtual machine for small devices, similar to Java
* [[Warren Abstract Machine]] - [[Prolog]], [[CSC]] [[GraphTalk]]
* [[Z-machine]] - [[Z-machine|Z-Code]]
* [[Zend Engine]] - [[PHP]]
* [[libJIT|libJIT Just-In-Time compilation library]] - [[libJIT|libJIT bytecode]]
{{col-2}}
;System (Hardware) virtual machine software
* [[ATLAS Transformation Language|ATL]] (A [[Model Transformation Language|MTL]] Virtual Machine)
* [[Bochs]], portable open source x86 and AMD64 PCs emulator
* [[CHARON-AXP]], provides virtualization of [[AlphaServer]] to migrate OpenVMS or Tru64 applications to x86 hardware
* [[CHARON-VAX]], provides virtualization of [[PDP-11]] or [[VAX]] hardware to migrate OpenVMS or Tru64 applications to x86 or HP integrity hardware
* [[CoLinux]] Open Source Linux inside Windows
* [[CoWare]] [[Virtual Platform]]
* [[Denali (operating system)|Denali]], uses paravirtualization of x86 for running para-virtualized PC operating systems.
* [[Hercules emulator]], free System/370, ESA/390, z/Mainframe
* [[Kernel-based Virtual Machine|KVM]]
* [[Logical Domains]]
* [[LynxSecure]] uses the [[Multiple Independent Levels of Security|MILS architecture]] to provide high assurance for embedded systems on x86
* [[Microsoft Virtual PC]] and [[Microsoft Virtual Server]]
* [[Oracle VM]]
* [[OVPsim]] is a freely available virtual platform simulator designed to simulate complex multiprocessor systems at very high speeds
* [[Parallels Workstation]], provides virtualization of x86 for running unmodified PC operating systems
* [[Parallels Desktop for Mac]], provides virtualization of x86 for running virtual machines on Mac OS X
* [[QEMU]], is a simulator based on a virtual machine.
* [[SheepShaver]].
* [[Simics]]
* [[Sun xVM]]
* [[SVISTA]]
* [[twoOStwo]]
* [[User-mode Linux]]
* [[VirtualBox]]
* [[Virtual Iron]] (Virtual Iron 3.1)
* [[VM (Operating system)|VM]] from [[International Business Machines|IBM]]
* [[VMLite]]
* [[VMware]] (ESX Server, Fusion, Virtual Server, Workstation, Player and ACE)
* [[Xen]] (Opensource)
* IBM POWER SYSTEMS

; OS-level virtualization software
* [[OpenVZ]]
* [[FreeVPS]]
* [[Linux-VServer]]
* [[FreeBSD Jail]]s
* [[Solaris Containers]]
* AIX [[Workload Partitions]]
{{col-end}}

===Extended descriptions of selected virtualization software===

The following software products are able to virtualize the hardware so that several operating systems can share it.

*[[Adeos]] is a [[Hardware Abstraction Layer]] that can be loaded as a [[Module (Linux)|Kernel Module]] in [[Linux]]. It allows the loading of a real-time kernel as a module, at the same time as Linux but with higher priority.
*[[Denali (operating system)|Denali]] uses [[paravirtualisation]] to provide high-performance virtual machines on x86 computers. Denali's virtual machines support specialised minimal OSs for Internet services. The system can scale to thousands of virtual machines. Denali does not preserve the application binary interface (ABI), and so applications must be recompiled to run within a library operating system; in this sense it is similar to the [[Exokernel]].
*OKL4 from [[Open Kernel Labs]] is designed for use in embedded systems and is primarily deployed in [[mobile phone|mobile phones]]. It is the only commercial hypervisor employing [[capability-based security]].
*[[OpenVZ]] - Operating System-level server virtualization solution, built on Linux.
*[[Parallels, Inc.|Parallels]] provides virtualization of x86 for running unmodified PC operating systems. It also uses a lightweight hypervisor technology in order to improve security and to increase the efficiency. Parallels has become popular for its ability to run Windows as a guest under [[Mac OS X]] on the [[Apple-Intel architecture]].
*[[QEMU]] is a simulator based on a virtual machine, which gives it the ability to emulate a variety of guest CPU architectures on many different host platforms.
*[[Returnil Virtual System]] allows you to virtualize your Windows based system and requires only a restart to rebuild the virtual machine.
* [[VirtualBox]] is an open source ([[GNU General Public License|GPL]])/[[Proprietary software|proprietary]] virtual machine developed by [[Sun Microsystems]]. It allows virtualization of x86 and supports various host operating systems including [[Microsoft Windows|Windows]], [[Linux]], [[Berkeley Software Distribution|BSD]] and [[Solaris (operating system)|Solaris]]. It also supports [[VMwares|VMware Workstation]] [[Virtual Machine Disk Format]].
* [[Virtual Iron]] provides virtual machines for x86 that run unmodified operating systems, such as Windows, Red Hat and SUSE. Virtual Iron open source virtualization technology implements [[native virtualization]], which delivers near-native performance for x86 operating systems.
*[[VMware]] provides virtual machines for x86 that can run unmodified PC operating systems. The technology involved in doing this is complex and also incurs (sometimes significant) performance overheads with hosted VMware products (VM Server and Workstation). ESX server provides near-native performance and a fully virtualized option (along with para-virtualization of some hardware components). Xen trades running of existing operating systems for running modified (paravirtualized) operating systems with improved performance. Virtual Iron provides full OS compatibility for existing or new OSes with near-native performance without the performance trade-offs between paravirualization and binary translation.
*[[Xen]] Virtualization system whose motivation differs from that of Denali in that it is intended to run a moderate number of full-featured operating systems, rather than a large number of specialised, lightweight ones.
*[[Kernel-based Virtual Machine|KVM]] is a [[Linux kernel]] module that enables a modified QEMU program to use hardware virtualization.
*[[libJIT|libJIT Just-In-Time Compilation library]] is a library for development of advanced [[Just-in-time compilation]] (JIT) in [[Virtual Machine]] implementations, [[Dynamic programming language]]s, and [[Scripting languages]]. Currently it is used for [[Common Intermediate Language]], [[Ruby (programming language)|Ruby]], [[Java bytecode|Java]], [[Domain-specific language|Domain-specific programming languages]].

==See also==
*[[Comparison of platform virtual machines]]
*[[Comparison of application virtual machines]]
*[[Virtual appliance]]
*[[International Computers Limited|ICL]]'s [[ICL VME|VME]] operating system
*[[Amazon Machine Image]]

==References==
<references/>

== Further reading ==
* Jim, Jr. Smith, Ravi Nair, James E. Smith, Heath Potter, Virtual Machines: Versatile Platforms For Systems And Processes, Publisher Morgan Kaufmann Publishers, May 2005, ISBN 1-55860-910-5, 656 pages
* Craig, Iain D. Virtual Machines. Springer, 2006, ISBN 1-85233-969-1

==External links==
*[http://acmqueue.com/modules.php?name=Content&pa=showpage&pid=168 The Reincarnation of Virtual Machines, Article on ACM Queue by Mendel Rosenblum, Co-Founder, VMware]
*[http://www.net-security.org/secworld.php?id=7837 Sandia National Laboratories Runs 1 Million Linux Kernels as Virtual Machines]
*[http://www.lri.fr/~quetier/papiers/EXPGRID.pdf Performances comparison between Xen, UML, Vserver and VMware]
*[http://doc.cat-v.org/inferno/4th_edition/dis_VM_design The design of the Inferno virtual machine by Phil Winterbottom and Rob Pike]

[[Category:Virtual machines| ]]
[[Category:Operating system technology]]
[[Category:Programming language implementation]]

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[[ar:آلة افتراضية]]
[[bs:Virtualna mašina]]
[[bg:Виртуална машина]]
[[cs:Virtuální stroj]]
[[da:Virtuel maskine]]
[[de:Virtuelle Maschine]]
[[et:Virtuaalmasin]]
[[es:Máquina virtual]]
[[eu:Makina birtual]]
[[fa:ماشین مجازی]]
[[fr:Machine virtuelle]]
[[ko:가상 머신]]
[[id:Mesin virtual]]
[[it:Macchina virtuale]]
[[he:מכונה וירטואלית]]
[[lo:ຄອມພິວເຕີຣ໌ຈໍາລອງ]]
[[hu:Virtuális számítógép]]
[[ml:വര്‍ച്ച്വല്‍ മെഷീന്‍]]
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[[zh:虛擬機器]]

Virtual machine

2010-01-20T16:20:34Z

64.22.228.134: /* System virtual machines */

A '''virtual machine''' ('''VM''') is a [[software]] implementation of a machine (i.e. a [[computer]]) that executes programs like a physical machine.

==Definitions==

A virtual machine was originally defined by [[Popek and Goldberg virtualization requirements|Popek and Goldberg]] as "an efficient, isolated duplicate of a real machine". Current use includes virtual machines which have no direct correspondence to any real hardware.<ref name="Smith_Nair_05">{{cite journal
| last = Smith
| first = James E.
| authorlink =
| coauthors = Nair, Ravi
| title = The Architecture of Virtual Machines
| journal = Computer
| volume = 38
| issue = 5
| pages = 32–38
| publisher = IEEE Computer Society
| location =
| date =
| url =
| doi = 10.1109/MC.2005.173
| id =
| accessdate = | year = 2005
}}</ref>

Virtual machines are separated into two major categories, based on their use and degree of correspondence to any real machine. A '''system virtual machine''' provides a complete [[system platform]] which supports the execution of a complete [[operating system]] (OS). In contrast, a '''process virtual machine''' is designed to run a single [[computer program|program]], which means that it supports a single [[process (computing)|process]]. An essential characteristic of a virtual machine is that the software running inside is limited to the resources and abstractions provided by the virtual machine—it cannot break out of its virtual world.

'''Example''':
A program written in [[Java (programming language)|Java]] receives services from the [[Java Runtime Environment]] (JRE) software by issuing commands to, and receiving the expected results from, the Java software. By providing these services to the program, the Java software is acting as a "virtual machine", taking the place of the operating system or hardware for which the program would ordinarily be tailored.

===System virtual machines===
{{see also|Platform virtualization|Comparison of platform virtual machines}}

System virtual machines (sometimes called '''hardware virtual machines''') allow the sharing of the underlying physical machine resources between different virtual machines, each running its own operating system. The software layer providing the virtualization is called a '''virtual machine monitor''' or [[hypervisor]]. A hypervisor can run on bare hardware ('''Type 1''' or '''native''' VM) or on top of an operating system ('''Type 2''' or '''hosted''' VM).

The main advantages of system VMs are:
* multiple OS environments can co-exist on the same computer, in strong isolation from each other
* the virtual machine can provide an [[instruction set]] architecture (ISA) that is somewhat different from that of the real machine
* application provisioning, maintenance, high availability and disaster recovery<ref>http://www.vmware.com/solutions/business-critical-apps/</ref>

The main disadvantage of system VMs is:
* a virtual machine is more efficient than a real machine because it accesses the hardware indirectly

Multiple VMs each running their own operating system (called '''guest operating system''') are frequently used in '''server consolidation''', where different services that used to run on individual machines in order to avoid interference are instead run in separate VMs on the same physical machine. This use is frequently called '''quality-of-service isolation''' (QoS isolation).

The desire to run multiple operating systems was the original motivation for virtual machines, as it allowed time-sharing a single computer between several single-tasking OSes. This technique requires a process to share the CPU resources between guest operating systems and [[memory virtualization]] to share the memory on the host.

The guest OSes do not have to be all the same, making it possible to run different OSes on the same computer (e.g., [[Microsoft Windows]] and [[Linux]], or older versions of an OS in order to support software that has not yet been ported to the latest version). The use of virtual machines to support different guest OSes is becoming popular in [[embedded systems]]; a typical use is to support a [[real-time operating system]] at the same time as a high-level OS such as Linux or Windows.

Another use is to [[Sandbox (software development)|sandbox]] an OS that is not trusted, possibly because it is a system under development. Virtual machines have other advantages for OS development, including better debugging access and faster reboots.<ref>http://www.vmwarez.com/2006/05/super-fast-server-reboots-another.html</ref>

Alternate techniques such as [[Solaris Zones]] provides a level of isolation within a ''single'' operating system. This does not have isolation as complete as a VM.

===Process virtual machines===

{{see also|Application virtualization|Run-time system|Comparison of application virtual machines}}

A process VM, sometimes called an '''application virtual machine''', runs as a normal application inside an OS and supports a single process. It is created when that process is started and destroyed when it exits. Its purpose is to provide a [[system platform|platform]]-independent programming environment that abstracts away details of the underlying hardware or operating system, and allows a program to execute in the same way on any platform.

A process VM provides a high-level abstraction — that of a [[high-level programming language]] (compared to the low-level ISA abstraction of the system VM). Process VMs are implemented using an [[Interpreter (computing)|interpreter]]; performance comparable to compiled programming languages is achieved by the use of [[just-in-time compilation]].

This type of VM has become popular with the [[Java (programming language)|Java programming language]], which is implemented using the [[Java virtual machine]]. Other examples include the [[Parrot virtual machine]], which serves as an [[abstraction layer]] for several interpreted languages, and the [[.NET Framework]], which runs on a VM called the [[Common Language Runtime]].

A special case of process VMs are systems that abstract over the communication mechanisms of a (potentially heterogeneous) [[computer cluster]]. Such a VM does not consist of a single process, but one process per physical machine in the cluster. They are designed to ease the task of programming parallel applications by letting the programmer focus on algorithms rather than the communication mechanisms provided by the interconnect and the OS. They do not hide the fact that communication takes place, and as such do not attempt to present the cluster as a single parallel machine.

Unlike other process VMs, these systems do not provide a specific programming language, but are embedded in an existing language; typically such a system provides bindings for several languages (e.g., [[C (programming language)|C]] and [[FORTRAN]]). Examples are PVM ([[Parallel Virtual Machine]]) and MPI ([[Message Passing Interface]]). They are not strictly virtual machines, as the applications running on top still have access to all OS services, and are therefore not confined to the system model provided by the "VM".

==Techniques==
===Emulation of the underlying raw hardware (native execution) ===
This approach is described as [[full virtualization]] of the hardware, and can be implemented using a Type 1 or Type 2 [[hypervisor]]. (A Type 1 hypervisor runs directly on the hardware; a Type 2 hypervisor runs on another operating system, such as [[Linux]]). Each virtual machine can run any operating system supported by the underlying hardware. Users can thus run two or more different "guest" operating systems simultaneously, in separate "private" virtual computers.

The pioneer system using this concept was IBM's [[IBM CP-40|CP-40]], the first (1967) version of IBM's [[CP/CMS]] (1967-1972) and the precursor to IBM's [[VM (operating system)|VM family]] (1972-present). With the VM architecture, most users run a relatively simple [[interactive computing]] single-user operating system, [[Conversational Monitor System|CMS]], as a "guest" on top of the VM control program ([[VM-CP]]). This approach kept the CMS design simple, as if it were running alone; the control program quietly provides multitasking and resource management services "behind the scenes". In addition to CMS, VM users can run any of the other IBM operating systems, such as [[MVS]] or [[z/OS]]. [[z/VM]] is the current version of VM, and is used to support hundreds or thousands of virtual machines on a given mainframe. Some installations use [[Linux for zSeries]] to run [[Web server]]s, where [[Linux]] runs as the operating system within many virtual machines.

Full virtualization is particularly helpful in operating system development, when experimental new code can be run at the same time as older, more stable, versions, each in a separate virtual machine. The process can even be [[Recursion#Recursion in computing|recursive]]: [[IBM]] debugged new versions of its virtual machine operating system, [[VM (operating system)|VM]], in a virtual machine running under an older version of VM, and even used this technique to simulate new hardware.<ref>See [[History of CP/CMS]] for IBM's use of virtual machines for operating system development and simulation of new hardware</ref>

The standard [[x86]] [[processor architecture]] as used in modern PCs does not actually meet the [[Popek and Goldberg virtualization requirements]]. Notably, there is no execution mode where all sensitive machine instructions always trap, which would allow per-instruction virtualization.

Despite these limitations, several software packages have managed to provide [[x86 virtualization|virtualization on the x86 architecture]], even though [[dynamic recompilation]] of privileged code, as first implemented by [[VMware]], incurs some performance overhead as compared to a VM running on a natively virtualizable architecture such as the IBM System/370 or [[Motorola 68020|Motorola MC68020]]. By now, several other software packages such as [[Virtual PC]], [[VirtualBox]], [[Parallels Workstation]] and [[Virtual Iron]] manage to implement virtualization on x86 hardware.

[[Intel]] and [[AMD]] have introduced features to their x86 processors to enable virtualization in hardware.

===Emulation of a non-native system===
Virtual machines can also perform the role of an [[emulator]], allowing software applications and [[operating systems]] written for another [[computer processor]] architecture to be run.

Some virtual machines emulate hardware that only exists as a detailed specification. For example:

* One of the first was the [[p-code machine]] specification, which allowed programmers to write [[Pascal programming language|Pascal]] [[Computer program|programs]] that would run on any computer running virtual machine software that correctly implemented the specification.
* The specification of the [[Java virtual machine]].
* The [[Common Language Infrastructure]] virtual machine at the heart of the [[.NET Framework|Microsoft .NET]] initiative.
* [[Open Firmware]] allows plug-in hardware to include boot-time diagnostics, configuration code, and device drivers that will run on any kind of CPU.

This technique allows diverse computers to run any software written to that specification; only the virtual machine software itself must be written separately for each type of computer on which it runs.

===Operating system-level virtualization===

''[[Operating System-level Virtualization]]'' is a server [[Platform virtualization|virtualization]] technology which virtualizes [[Server (computing)|server]]s on an [[operating system]] (kernel) layer. It can be thought of as partitioning: a single physical server is sliced into multiple small partitions (otherwise called virtual environments (VE), [[virtual private server]]s (VPS), guests, zones, etc.); each such partition looks and feels like a real server, from the point of view of its users.

For example, Solaris Zones supports multiple guest OSes running under the same OS (such as Solaris 10). All guest OSes have to use the same kernel level and cannot run as different OS versions. Solaris native Zones also requires that the host OS be a version of Solaris; other OSes from other manufacturers are not supported.{{Fact|date=September 2008}},however you need to use Solaris Branded zones to use another OSes as zones.

Another example is [[Workload_partitions#System_WPAR|System Workload Partitions]] (WPARs), introduced in the IBM AIX 6.1 operating system. System WPARs are software partitions running under one instance of the global AIX OS environment.

The operating system level architecture has low overhead that helps to maximize efficient use of server resources. The virtualization introduces only a negligible overhead and allows running hundreds of [[virtual private server]]s on a single physical server. In contrast, approaches such as [[full virtualization]] (like [[VMware]]) and [[paravirtualization]] (like [[Xen]] or [[User-mode Linux|UML]]) cannot achieve such level of density, due to overhead of running multiple kernels. From the other side, operating system-level virtualization does not allow running different operating systems (i.e. different kernels), although different libraries, distributions etc. are possible.

{{main|operating system-level virtualization}}

==List of hardware with virtual machine support==

* [[Alcatel-Lucent]] [[3B21D|3B20D/3B21D]] emulated on [[commercial off-the-shelf]] computers with '''3B2OE''' or '''3B21E''' system
* [[AMD-V]] (formerly code-named Pacifica)
* [[ARM architecture|ARM TrustZone]]
* Boston Circuits gCore (grid-on-chip) with 16 [[ARC International|ARC]] 750D cores and Time-machine hardware virtualization module.
* [[Freescale]] [[PowerPC]] MPC8572 and MPC8641D
* [[IBM]] [[System/370]], [[System/390]], and [[zSeries]] mainframes
* [[Intel VT]] (formerly code-named Vanderpool)
* [[Sun Microsystems]] sun4v (UltraSPARC [[UltraSPARC T1|T1]] and [[UltraSPARC T2|T2]]) -- utilized by [[Logical Domains]]
{{seealso|x86 virtualization#Hardware support}}
* [[HP]] vPAR and cell based [[HP nPar (Hard Partitioning)|nPAR]]
* [[GE]] Project MAC then
* [[Honeywell]] Multics systems
* [[Honeywell]] 200/2000 systems Liberator replacing IBM 14xx systems, Level 62/64/66 GCOS
* [[IBM]] System/360 Model 145 Hardware emulator for Honeywell 200/2000 systems
* [[RCA]] Spectra/70 Series emulated IBM System/360
* [[NAS]] CPUs emulated IBM and Amdahl machines
* [[Honeywell]] Level 6 minicomputers emulated predecessor 316/516/716 minis
* [[Xerox]] Sigma 6 CPUs were modified to emulate GE/Honeywell 600/6000 systems

==List of virtual machine software==
{{external links}}
{{col-begin}}
{{col-2}}
;Process (Application) virtual machine software
* [[Baan]] Bshell Virtual Machine - Baan 4GL
* [[Common Language Infrastructure]] - [[C Sharp (programming language)|C#]], [[Visual Basic .NET]], [[J Sharp|J#]], [[C++/CLI]] (formerly [[Managed Extensions for C++|Managed C++]])
* [[Dalvik virtual machine]] - part of the [[Android mobile phone platform]]
* [http://doc.cat-v.org/inferno/4th_edition/dis_VM_design Dis] - [[Inferno operating system]] and its [[Limbo programming language]]
* [[Dosbox]]
* [[EiffelStudio]] for the [[Eiffel (programming language)|Eiffel programming language]]
* [[Erlang programming language]]
* [[Forth virtual machine]] - [[Forth (programming language)|Forth]]
* [[Glulx]] - [[Glulx]], [[Z-machine|Z-code]]
* Hec - [[Bytecode|Hasm Assembler]]
* [[Java Virtual Machine]] - [[Java (programming language)|Java]], [[Nice programming language|Nice]], [[REXX|NetREXX]]
* [[Juke Virtual Machine]] - A public domain ECMA-335 compatible virtual machine hosted at Google code.
* [[LLVM|Low Level Virtual Machine (LLVM)]] - currently [[C (programming language)|C]], [[C++]], Stacker
* [[Lua programming language|Lua]]
* [[Macromedia Flash Player]] - [[SWF]]
* Memory Array Redcode Simulator (MARS) - Virtual machine that executes [[Corewars]] programs.
* [[MMIX]] - [[MMIX]]AL
* Neko virtual machine - currently Neko and [[haXe]]
* [[O-code machine]] - [[BCPL]]
* [[p-code machine]] - [[Pascal programming language|Pascal]]
* [[Parrot virtual machine|Parrot]] - [[Perl 6]]
* [[Perl|Perl virtual machine]] - [[Perl]]
* [[CPython]] - [[Python (programming language)|Python]]
* [[YARV]] - [[Ruby MRI]]
* [[Rubinius]] - [[Ruby (programming language)|Ruby]]
* [[ScummVM]] - [[Scumm]]
* [[SECD machine]] - [[ISWIM]], [[Lispkit Lisp]]
* [[Sed]] the stream-editor can also be seen as a VM with 2 storage spaces.
* [[Smalltalk|Smalltalk virtual machine]] - [[Smalltalk]]
* [[SQLite|SQLite virtual machine]] - [[SQLite|SQLite opcodes]]
* [[Squeak|Squeak virtual machine]] - [[Squeak]]
* [[SWEET16]]
* [[Tamarin (JavaScript engine)]] - ActionScript VM in Flash 9
* [[TrueType|TrueType virtual machine]] - [[TrueType]]
* [[Valgrind]] - checking of memory accesses and leaks in [[x86]]/[[x86-64]] code under [[Linux]]
* [[Virtual Processor]] (VP) from [[Tao Group]] ([[United Kingdom|UK]]).
* [[VX32|VX32 virtual machine]] - application-level virtualization for native code
* Waba - Virtual machine for small devices, similar to Java
* [[Warren Abstract Machine]] - [[Prolog]], [[CSC]] [[GraphTalk]]
* [[Z-machine]] - [[Z-machine|Z-Code]]
* [[Zend Engine]] - [[PHP]]
* [[libJIT|libJIT Just-In-Time compilation library]] - [[libJIT|libJIT bytecode]]
{{col-2}}
;System (Hardware) virtual machine software
* [[ATLAS Transformation Language|ATL]] (A [[Model Transformation Language|MTL]] Virtual Machine)
* [[Bochs]], portable open source x86 and AMD64 PCs emulator
* [[CHARON-AXP]], provides virtualization of [[AlphaServer]] to migrate OpenVMS or Tru64 applications to x86 hardware
* [[CHARON-VAX]], provides virtualization of [[PDP-11]] or [[VAX]] hardware to migrate OpenVMS or Tru64 applications to x86 or HP integrity hardware
* [[CoLinux]] Open Source Linux inside Windows
* [[CoWare]] [[Virtual Platform]]
* [[Denali (operating system)|Denali]], uses paravirtualization of x86 for running para-virtualized PC operating systems.
* [[Hercules emulator]], free System/370, ESA/390, z/Mainframe
* [[Kernel-based Virtual Machine|KVM]]
* [[Logical Domains]]
* [[LynxSecure]] uses the [[Multiple Independent Levels of Security|MILS architecture]] to provide high assurance for embedded systems on x86
* [[Microsoft Virtual PC]] and [[Microsoft Virtual Server]]
* [[Oracle VM]]
* [[OVPsim]] is a freely available virtual platform simulator designed to simulate complex multiprocessor systems at very high speeds
* [[Parallels Workstation]], provides virtualization of x86 for running unmodified PC operating systems
* [[Parallels Desktop for Mac]], provides virtualization of x86 for running virtual machines on Mac OS X
* [[QEMU]], is a simulator based on a virtual machine.
* [[SheepShaver]].
* [[Simics]]
* [[Sun xVM]]
* [[SVISTA]]
* [[twoOStwo]]
* [[User-mode Linux]]
* [[VirtualBox]]
* [[Virtual Iron]] (Virtual Iron 3.1)
* [[VM (Operating system)|VM]] from [[International Business Machines|IBM]]
* [[VMLite]]
* [[VMware]] (ESX Server, Fusion, Virtual Server, Workstation, Player and ACE)
* [[Xen]] (Opensource)
* IBM POWER SYSTEMS

; OS-level virtualization software
* [[OpenVZ]]
* [[FreeVPS]]
* [[Linux-VServer]]
* [[FreeBSD Jail]]s
* [[Solaris Containers]]
* AIX [[Workload Partitions]]
{{col-end}}

===Extended descriptions of selected virtualization software===

The following software products are able to virtualize the hardware so that several operating systems can share it.

*[[Adeos]] is a [[Hardware Abstraction Layer]] that can be loaded as a [[Module (Linux)|Kernel Module]] in [[Linux]]. It allows the loading of a real-time kernel as a module, at the same time as Linux but with higher priority.
*[[Denali (operating system)|Denali]] uses [[paravirtualisation]] to provide high-performance virtual machines on x86 computers. Denali's virtual machines support specialised minimal OSs for Internet services. The system can scale to thousands of virtual machines. Denali does not preserve the application binary interface (ABI), and so applications must be recompiled to run within a library operating system; in this sense it is similar to the [[Exokernel]].
*OKL4 from [[Open Kernel Labs]] is designed for use in embedded systems and is primarily deployed in [[mobile phone|mobile phones]]. It is the only commercial hypervisor employing [[capability-based security]].
*[[OpenVZ]] - Operating System-level server virtualization solution, built on Linux.
*[[Parallels, Inc.|Parallels]] provides virtualization of x86 for running unmodified PC operating systems. It also uses a lightweight hypervisor technology in order to improve security and to increase the efficiency. Parallels has become popular for its ability to run Windows as a guest under [[Mac OS X]] on the [[Apple-Intel architecture]].
*[[QEMU]] is a simulator based on a virtual machine, which gives it the ability to emulate a variety of guest CPU architectures on many different host platforms.
*[[Returnil Virtual System]] allows you to virtualize your Windows based system and requires only a restart to rebuild the virtual machine.
* [[VirtualBox]] is an open source ([[GNU General Public License|GPL]])/[[Proprietary software|proprietary]] virtual machine developed by [[Sun Microsystems]]. It allows virtualization of x86 and supports various host operating systems including [[Microsoft Windows|Windows]], [[Linux]], [[Berkeley Software Distribution|BSD]] and [[Solaris (operating system)|Solaris]]. It also supports [[VMwares|VMware Workstation]] [[Virtual Machine Disk Format]].
* [[Virtual Iron]] provides virtual machines for x86 that run unmodified operating systems, such as Windows, Red Hat and SUSE. Virtual Iron open source virtualization technology implements [[native virtualization]], which delivers near-native performance for x86 operating systems.
*[[VMware]] provides virtual machines for x86 that can run unmodified PC operating systems. The technology involved in doing this is complex and also incurs (sometimes significant) performance overheads with hosted VMware products (VM Server and Workstation). ESX server provides near-native performance and a fully virtualized option (along with para-virtualization of some hardware components). Xen trades running of existing operating systems for running modified (paravirtualized) operating systems with improved performance. Virtual Iron provides full OS compatibility for existing or new OSes with near-native performance without the performance trade-offs between paravirualization and binary translation.
*[[Xen]] Virtualization system whose motivation differs from that of Denali in that it is intended to run a moderate number of full-featured operating systems, rather than a large number of specialised, lightweight ones.
*[[Kernel-based Virtual Machine|KVM]] is a [[Linux kernel]] module that enables a modified QEMU program to use hardware virtualization.
*[[libJIT|libJIT Just-In-Time Compilation library]] is a library for development of advanced [[Just-in-time compilation]] (JIT) in [[Virtual Machine]] implementations, [[Dynamic programming language]]s, and [[Scripting languages]]. Currently it is used for [[Common Intermediate Language]], [[Ruby (programming language)|Ruby]], [[Java bytecode|Java]], [[Domain-specific language|Domain-specific programming languages]].

==See also==
*[[Comparison of platform virtual machines]]
*[[Comparison of application virtual machines]]
*[[Virtual appliance]]
*[[International Computers Limited|ICL]]'s [[ICL VME|VME]] operating system
*[[Amazon Machine Image]]

==References==
<references/>

== Further reading ==
* Jim, Jr. Smith, Ravi Nair, James E. Smith, Heath Potter, Virtual Machines: Versatile Platforms For Systems And Processes, Publisher Morgan Kaufmann Publishers, May 2005, ISBN 1-55860-910-5, 656 pages
* Craig, Iain D. Virtual Machines. Springer, 2006, ISBN 1-85233-969-1

==External links==
*[http://acmqueue.com/modules.php?name=Content&pa=showpage&pid=168 The Reincarnation of Virtual Machines, Article on ACM Queue by Mendel Rosenblum, Co-Founder, VMware]
*[http://www.net-security.org/secworld.php?id=7837 Sandia National Laboratories Runs 1 Million Linux Kernels as Virtual Machines]
*[http://www.lri.fr/~quetier/papiers/EXPGRID.pdf Performances comparison between Xen, UML, Vserver and VMware]
*[http://doc.cat-v.org/inferno/4th_edition/dis_VM_design The design of the Inferno virtual machine by Phil Winterbottom and Rob Pike]

[[Category:Virtual machines| ]]
[[Category:Operating system technology]]
[[Category:Programming language implementation]]

[[af:Virtuele masjien]]
[[ar:آلة افتراضية]]
[[bs:Virtualna mašina]]
[[bg:Виртуална машина]]
[[cs:Virtuální stroj]]
[[da:Virtuel maskine]]
[[de:Virtuelle Maschine]]
[[et:Virtuaalmasin]]
[[es:Máquina virtual]]
[[eu:Makina birtual]]
[[fa:ماشین مجازی]]
[[fr:Machine virtuelle]]
[[ko:가상 머신]]
[[id:Mesin virtual]]
[[it:Macchina virtuale]]
[[he:מכונה וירטואלית]]
[[lo:ຄອມພິວເຕີຣ໌ຈໍາລອງ]]
[[hu:Virtuális számítógép]]
[[ml:വര്‍ച്ച്വല്‍ മെഷീന്‍]]
[[ms:Mesin maya]]
[[nl:Virtuele machine]]
[[ja:仮想機械]]
[[pl:Maszyna wirtualna]]
[[pt:Máquina virtual]]
[[ru:Виртуальная машина]]
[[simple:Virtual machine]]
[[fi:Virtuaalikone]]
[[sv:Virtuell maskin]]
[[tr:Sanal makine]]
[[uk:Віртуальна машина]]
[[vi:Máy ảo]]
[[yi:ווירטועל מאשין]]
[[zh:虛擬機器]]

Methylparaben

2009-04-21T20:10:39Z

64.22.228.134: /* Safety */

{{Otheruses4|this particular compound|the class of hydroxybenzoate esters, including discussion on possible health effects|paraben}}
{{chembox
| ImageFile = Hydroxypropyltrimonium.svg
| ImageSize = 120px
| IUPACName = Methyl 4-hydroxybenzoate
| OtherNames = Methyl paraben; Methyl ''p''-hydroxybenzoate; Methyl parahydroxybenzoate; Nipagin; [[E number]] E218
| Section1 = {{Chembox Identifiers
| CASNo = 99-76-3
| PubChem = 7456
| SMILES = COC(=O)C1=CC=C(C=C1)O
}}
| Section2 = {{Chembox Properties
| Formula = C8H8O3
| MolarMass = 152.15 g/mol
| Appearance =
| Density =
| MeltingPt =
| BoilingPt =
| Solubility = }}
| Section3 = {{Chembox Hazards
| MainHazards =
| FlashPt =
| Autoignition = }}
}}

'''Methylparaben''', also '''methyl paraben''', one of the [[parabens]], has formula CH3(C6H4(OH)COO). It is the [[methyl]] [[ester]] of [[P-Hydroxybenzoic acid|''p''-hydroxybenzoic acid]].

==Uses==
Methylparaben is an [[antifungal]] that is widely used as a preservative for food, drugs, and cosmetics. The compound is often found in carpules of local anaesthetic, acting as a bacteriostatic agent and preservative.

Methylparaben (also called Nipigin M, Tegosept, and Mycocten) is commonly used as an anti-fungal agent in ''[[Drosophila]]'' food media. Usage of methylparaben is known to slow ''Drosophila'' growth rate in the larval and pupal stages.

==Safety==
Methylparaben is readily absorbed from the gastrointestinal tract or through the skin.<ref name="Soni">{{cite journal |author=Soni MG, Taylor SL, Greenberg NA, Burdock GA |title=Evaluation of the health aspects of methyl paraben: a review of the published literature |journal=Food Chem. Toxicol. |volume=40 |issue=10 |pages=1335–73 |year=2002 |month=October |pmid=12387298 |doi= 10.1016/S0278-6915(02)00107-2|url=http://linkinghub.elsevier.com/retrieve/pii/S0278691502001072}}</ref> It is [[hydrolysis|hydrolyzed]] to ''p''-hydroxybenzoic acid and rapidly excreted without accumulation in the body.<ref name="Soni"/> Acute toxicity studies have shown that methylparaben is practically non-toxic by both oral and [[Intraperitoneal injection|parenteral]] administration.<ref name="Soni"/> In a population with normal skin, methylparaben is practically non-irritating and non-sensitizing; however, allergic reactions to ingested parabens have been reported.<ref name="Soni"/>
Methylparaben can be found in many of the leading skin/face products.

==See also==
* [[Ethylparaben]]
* [[Propylparaben]]
* [[Butylparaben]]

==References==
{{reflist}}

==External links==
* [http://toxnet.nlm.nih.gov/cgi-bin/sis/search/r?dbs+hsdb:@term+@rn+99-76-3 Methylparaben] at Hazardous Substances Data Bank
* [http://hpd.nlm.nih.gov/cgi-bin/household/brands?tbl=chem&id=773 Methylparaben] at Household Products Database

[[Category:Phenols]]
[[Category:Carboxylate esters]]

[[de:4-Hydroxybenzoesäuremethylester]]
[[hu:Metil-parahidroxibenzoát]]
[[nl:Methylparabeen]]
[[ru:Нипагин]]

Unit testing

2008-04-23T15:38:22Z

64.22.228.134: /* Design */ Added missing parenthesis to code example.

In [[computer programming]], '''unit testing''' is a procedure used to validate that individual units of [[source code]] are working properly. A unit is the smallest testable part of an application. In [[procedural programming]] a unit may be an individual program, function, procedure, etc., while in [[object-oriented programming]], the smallest unit is a [[method (computer science)|method]], which may belong to a base/super class, abstract class or derived/child class.

Ideally, each [[test case]] is independent from the others; [[mock object| mock]] or [[Mock object#Mocks and fakes|fake]] objects<ref name="mocksarentstubs">{{cite-web|url=http://martinfowler.com/articles/mocksArentStubs.html|title=Mocks aren't Stubs|date=2007-01-02|last=Fowler|first=Martin|authorlink=Martin Fowler|accessdate=2008-04-01}}</ref> as well as [[test harness]]es can be used to assist testing a module in isolation. Unit testing is typically done by [[software developer|developer]]s and not by [[software tester]]s or [[end-user]]s.

{{portal|Software Testing}}
== Benefits ==

The goal of unit testing is to isolate each part of the program and show that the individual parts are correct. A unit test provides a strict, written contract that the piece of code must satisfy. As a result, it affords several benefits.

===Facilitates change===

Unit testing allows the programmer to [[refactoring|refactor]] code at a later date, and make sure the module still works correctly (i.e. [[regression testing]]). The procedure is to write test cases for all [[subroutine|function]]s and [[method (computer science)|method]]s so that whenever a change causes a fault, it can be quickly identified and fixed.

Readily-available unit tests make it easy for the programmer to check whether a piece of code is still working properly. Good unit test design produces test cases that [[code coverage|cover]] all paths through the unit with attention paid to loop conditions.

In continuous unit testing environments, through the inherent practice of sustained maintenance, unit tests will continue to accurately reflect the intended use of the executable and code in the face of any change. Depending upon established development practices and unit test coverage, up-to-the-second accuracy can be maintained.

===Simplifies integration===

Unit testing helps to eliminate uncertainty in the units themselves and can be used in a [[Top-down and bottom-up design|bottom-up]] testing style approach. By testing the parts of a program first and then testing the sum of its parts, [[integration testing]] becomes much easier.

A heavily debated matter exists in assessing the need to perform manual integration testing. While an elaborate hierarchy of unit tests may seem to have achieved integration testing, this presents a false sense of confidence since integration testing evaluates many other objectives that can only be proven through the human factor. Some argue that given a sufficient variety of [[test automation]] systems, integration testing by a human test group is unnecessary. Realistically, the actual need will ultimately depend upon the characteristics of the product being developed and its intended uses. Additionally, the human or [[manual testing]] will greatly depend on the availability of resources in the organization.

===Documentation===

'''Unit testing''' provides a sort of living documentation of the system. Developers looking to learn what functionality is provided by a unit and how to use it can look at the unit tests to gain a basic understanding of the unit [[Application programming interface|API]].

Unit [[test case]]s embody characteristics that are critical to the success of the unit. These characteristics can indicate appropriate/inappropriate use of a unit as well as negative behaviors that are to be trapped by the unit. A unit test case, in and of itself, documents these critical characteristics, although many software development environments do not rely solely upon code to document the product in development.

On the other hand, ordinary narrative documentation is more susceptible to drifting from the implementation of the program and will thus become outdated (e.g. design changes, [[feature creep]], relaxed practices to keep documents up to date).

===Design===

When software is developed using a test-driven approach, the Unit-Test may take the place of formal design. Each unit test can be seen as a design element, specifying classes, methods, and observable behaviour. The following java example will help illustrate this point.

Here is a test class that specifies a number of elements of the implementation. First, that there must be an interface called Adder, and an implementing class with a no arg constructor called AdderImpl. It goes on to assert that the Adder interface should have a method called add, with two integer parameters, which returns another integer. It also specifies the behaviour of this method for a small range of values.

<code>
public class TestAdder {
public void testSum() {
Adder adder = new AdderImpl();
assertTrue(adder.add(1,1) == 2);
assertTrue(adder.add(1,2) == 3);
assertTrue(adder.add(2,2) == 4);
assertTrue(adder.add(0,0) == 0);
assertTrue(adder.add(-1,-2) == -3);
assertTrue(adder.add(-1,1) == 0);
assertTrue(adder.add(1234,988) == 2222);
}
}
</code>

In this case the unit test, having been written first, acts as a design document specifying the form and behaviour of a desired solution, but not the implementation details, which are left as an exercise for the programmer. Following the 'do the simplest thing that could possibly work' practice, the easiest solution that will make the test pass is shown below.

<code>
interface Adder {
int add(int a, int b);
}
class AdderImpl implements Adder {
int add(int a, int b) {
return a + b;
}
}
</code>

Unlike other, diagram based, design methods, using a unit-test as a design has one significant advantage. The design document, the unit-test itself, can be used to verify that the implementation adheres to the design. UML suffers from the fact that although a diagram may name a class Customer, the developer can go ahead and call that class Wibble if they pleased, and nothing would raise any alarm bells anywhere in the system. In the unit-test is the design paradigm, the tests would never pass if the developer did not implement the solution according to the design.

It is true that unit-testing lacks some of the accessibility of a diagram, but as UML diagrams are now easily generated for most modern languages by free tools, usually available as free extensions to IDEs. It is hard to argue for the purchase of expensive UML design suites, when tools like xUnit are available for free, and which perform the same job better, outsourcing to another system the work graphical rendering of a view for human consumption.

==Separation of interface from implementation==

Because some classes may have [[Reference (computer science)|reference]]s to other classes, testing a class can frequently spill over into testing another class. A common example of this is classes that depend on a [[database]]: in order to test the class, the tester often writes code that interacts with the database. This is a mistake, because a unit test should never go outside of its own class boundary. Instead, the software developer should create an abstract interface around the database connection, and then implement that interface with their own [[mock object]]. By abstracting this necessary attachment from the code (temporarily reducing the net effective coupling), the independent unit can be more thoroughly tested than may have been previously achieved. This results in a higher quality unit that is also more maintainable.

==Limitations of unit testing==

Testing, in general, cannot be expected to catch every error in the program. The same is true for unit testing. By definition, it only tests the functionality of the units themselves. Therefore, it may not catch integration errors, [[Performance testing|performance]] problems, or other system-wide issues. Unit testing is more effective if it is used in conjunction with other [[Software testing#Software testing activities|software testing activities]].

Like all forms of software testing, unit tests can only show the presence of errors; it cannot show the absence of errors.

Software testing is a combinatorial problem. For example, every boolean decision statement requires at least two tests: one with an outcome of "true" and one with an outcome of "false". As a result, for every line of code written, programmers often need 3 to 5 lines of test code.<ref>{{cite web|last=Cramblitt|first=Bob|author-link=Bob Cramblitt| title=Alberto Savoia sings the praises of software testing|date=2007-09-20| accessdate=2007-11-29|url=http://searchsoftwarequality.techtarget.com/originalContent/0,289142,sid92_gci1273161,00.html}}</ref>

To obtain the intended benefits from unit testing, a rigorous sense of discipline is needed throughout the software development process. It is essential to keep careful records, not only of the tests that have been performed, but also of all changes that have been made to the source code of this or any other unit in the software. Use of a [[version control]] system is essential. If a later version of the unit fails a particular test that it had previously passed, the version-control software can provide a list of the source code changes (if any) that have been applied to the unit since that time.

It is also essential to implement a sustainable process for ensuring that test case failures are reviewed daily and addressed immediately. <ref>{{cite web|last=daVeiga|first=Nada|author-link=Nada daVeiga| title=Change Code Without Fear: Utilize a regression safety net|date=2009-02-06| accessdate=2008-02-08|url=http://www.ddj.com/development-tools/206105233}}</ref> If such a process is not implemented and ingrained into the team's workflow, the application will evolve out of sync with the unit test suite—- increasing false positives and reducing the effectiveness of the test suite.

==Applications==
===Extreme Programming===

Unit testing is the cornerstone of [[Extreme Programming]] (XP), which relies on an automated [[list of unit testing frameworks|unit testing framework]]. This automated unit testing framework can be either third party, e.g. [[xUnit]], or created within the development group.

Extreme Programming uses the creation of unit tests for [[test-driven development]]. The developer writes a unit test that exposes either a software requirement or a defect. This test will fail because either the requirement isn't implemented yet, or because it intentionally exposes a defect in the existing code. Then, the developer writes the simplest code to make the test, along with other tests, pass.

Most code in a system is unit tested, but not necessarily all paths through the code. XP mandates a 'test everything that can possibly break' strategy, over the tradition 'test every execution path' method. This leads XP developers to develop fewer tests than classical methods, but this isn't really a problem, more a restatement of fact, as classical methods have rarely ever been followed methodically enough for all execution paths to have been thoroughly tested. XP simply recognises that testing is rarely exhaustive (because often that is too expensive and time consuming to be economically viable), and provides guidance on how to effectively focus the limited resources we can afford expend on the problem.

Crucially, the test code is considered a first class project artefact in that it is maintained at the same quality as the implementation code, with all duplication removed. Developers release unit testing code to the code repository in conjunction with the code it tests. XP's thorough unit testing allows the benefits mentioned above, such as simpler and more confident code development and [[refactoring]], simplified code integration, accurate documentation, and more modular designs. These unit tests are also constantly run as a form of [[regression test]].`

=== Techniques ===
Unit testing is commonly [[Test automation|automated]], but may still be performed manually. The [[Institute of Electrical and Electronics Engineers|IEEE]] does not favor one over the other.<ref>IEEE Standards Board, [http://iteso.mx/~pgutierrez/calidad/Estandares/IEEE%201008.pdf "IEEE Standard for Software Unit Testing: An American National Standard, ANSI/IEEE Std 1008-1987"] in ''IEEE Standards: Software Engineering, Volume Two: Process Standards; 1999 Edition; published by The Institute of Electrical and Electronics Engineers, Inc.'' Software Engineering Technical Committee of the IEEE Computer Society.</ref> A manual approach to unit testing may employ a step-by-step instructional document. Nevertheless, the objective in unit testing is to isolate a unit and validate its correctness. Automation is efficient for achieving this, and enables the many benefits listed in this article. Conversely, if not planned carefully, a careless manual unit test case may execute as an integration test case that involves many software components, and thus preclude the achievement of most if not all of the goals established for unit testing.

Under the automated approach, to fully realize the effect of isolation, the unit or code body subjected to the unit test is executed within a [[List of unit testing frameworks|framework]] outside of its natural environment, that is, outside of the product or calling context for which it was originally created. Testing in an isolated manner has the benefit of revealing unnecessary dependencies between the code being tested and other units or data spaces in the product. These dependencies can then be eliminated.

Using an automation framework, the developer codes criteria into the test to verify the correctness of the unit. During execution of the test cases, the framework logs those that fail any criterion. Many frameworks will also automatically flag and report in a summary these failed test cases. Depending upon the severity of a failure, the framework may halt subsequent testing.

As a consequence, unit testing is traditionally a motivator for programmers to create [[Coupling (computer science)|decoupled]] and [[cohesion (computer science)|cohesive]] code bodies. This practice promotes healthy habits in software development. [[Design pattern (computer science)|Design patterns]], unit testing, and refactoring often work together so that the most ideal solution may emerge.

===Unit testing frameworks===

Unit testing frameworks, which help simplify the process of unit testing, have been developed for a
[[List of unit testing frameworks|wide variety of languages]].
It is generally possible to perform unit testing without the support of specific framework by writing client code that exercises the units under test and uses assertion, exception, or early exit mechanisms to signal failure. This approach is valuable in that there is a non-negligible barrier to the adoption of unit testing. However, it is also limited in that many advanced features of a proper framework are missing or must be hand-coded.

==See also==

* [[Characterization Test]]
* [[Design predicates]]
* [[Extreme Programming]]
* [[Integration testing]]
* [[List of unit testing frameworks]]
* [[Regression testing]]
* [[Software testing]]
* [[Test case]]
* [[Test-driven development]]
* [[xUnit]] - a family of unit testing frameworks.

==Notes==
{{reflist}}
{{refimprove|date=November 2007}}

==External links==
* [http://weblogs.asp.net/rosherove/archive/2008/01/17/the-evolution-of-unit-testing-and-syntax.aspx The evolution of Unit Testing Syntax and Semantics]

* [http://www.xprogramming.com/testfram.htm Kent Beck's original testing framework paper]
* [http://The.ArtOfUnitTesting.com/ Roy Osherove's book excerpts on Unit Testing: The Art Of Unit Testing]
* [http://www.softdevarticles.com/modules/weblinks/viewcat.php?cid=34 List of articles on unit testing]
* [http://shebanation.com/2007/08/21/a-brief-history-of-test-frameworks/ History of unit test frameworks (Andrew Shebanow)]
* [http://geosoft.no/development/unittesting.html Unit Testing Guidelines from GeoSoft]

[[Category:Unit testing|*]]
[[Category:Software testing]]
[[Category:Extreme Programming]]

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[[de:Modultest]]
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[[fr:Test unitaire]]
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[[nl:Unittesten]]
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[[pt:Teste unitário]]
[[ru:Юнит-тестирование]]
[[zh:单元测试]]

Neo-ninja

2008-01-11T19:56:26Z

64.22.228.134: /* See also */

{{Merge|Bullshido|date=September 2007}}
{{Unreferenced|date=January 2007}} {{expert}}'''Neo-ninja''', sometimes used in conjunction with the term ''Gendai Ninpo'', refers to modern [[martial arts]] schools which claim to teach elements of the historic [[ninja]] of [[Japan]], or base their school's philosophy upon traits attributed to the historic ninja of Japan.

Among Neo-ninja schools there is a lot of variety. Most schools teach eclectic curricula from a variety of different cultures and sources. Some of these schools are clear about the mixed provenance of their history and teachings. Others attempt to obscure the sources of their teachings with an aura of mysticism. Many neo-ninja schools came into being in the 1980s during the "ninja boom."

== See also ==
* [[Ashida Kim]]
* [[Count Dante]]
* [[Frank Dux]]
* [[Rick Tew]]
* [[Glen Levy]]
* [[McDojo]]
* [[Ninjutsu]]

[[Category:Ninjutsu]]
[[Category:Martial arts terms]]

{{martialart-term-stub}}

Talk:Neo-ninja

2008-01-11T19:50:28Z

64.22.228.134:

{{martialartsproject|class=Stub}}
re: Neo-ninja. I rv'ed this article back to the last coherent version, it was vandalism. Please do not blnak the rticles if suggestinog for AfD or CSD. Xaosflux 16:55, 27 November 2005 (UTC)

I re-added the link to a Wikipedia page. Considering the way the Discussion went, I think it is appropriate.
[[User:TrueGamerOmega|TrueGamerOmega]] 00:15, 26 February 2006 (UTC)

Having the "Modern Members" section at the bottom is unnecassary, sloppy, and it is malicious against the members of Bujinkan, you know, the only Ninjutsu practitioners who can PROVE their lagacy.[[User:216.79.146.64|216.79.146.64]] 16:07, 6 March 2006 (UTC)

Should Count Dante be listed here as a neo-ninja? He was a colorful character, but I don't think he ever claimed to teach ninjutsu. [[User:JN322|JN322]] 00:29, 4 March 2007 (UTC)

Added Rick Tew and Glen Levy to list of those who claim to practice Ninjutsu (Spelled Ninjitsu on Mr. Tew's website and the National Geographic "Fight Science" website that features Mr. Levy). Both of their claims appear to be unsubstantiated and not strongly supported by any documented evidence.
[[User:Kanarime|Kanarime]] 13:48, 11 January 2008 (UTC)

Talk:Neo-ninja

2008-01-11T19:49:21Z

64.22.228.134:

{{martialartsproject|class=Stub}}
re: Neo-ninja. I rv'ed this article back to the last coherent version, it was vandalism. Please do not blnak the rticles if suggestinog for AfD or CSD. Xaosflux 16:55, 27 November 2005 (UTC)

I re-added the link to a Wikipedia page. Considering the way the Discussion went, I think it is appropriate.
[[User:TrueGamerOmega|TrueGamerOmega]] 00:15, 26 February 2006 (UTC)

Having the "Modern Members" section at the bottom is unnecassary, sloppy, and it is malicious against the members of Bujinkan, you know, the only Ninjutsu practitioners who can PROVE their lagacy.[[User:216.79.146.64|216.79.146.64]] 16:07, 6 March 2006 (UTC)

Should Count Dante be listed here as a neo-ninja? He was a colorful character, but I don't think he ever claimed to teach ninjutsu. [[User:JN322|JN322]] 00:29, 4 March 2007 (UTC)

Added Rick Tew and Glen Levy to list of those who claim to practice Ninjutsu (Spelled Ninjitsu on Mr. Tew's website and the National Geographic "Fight Science" website that features Mr. Levy). Both of their claims appear to be unsubstantiated and not strongly supported by any documented evidence.[[User:Kanarime|Kanarime]] 13:48, 11 January 2008 (UTC)

Neo-ninja

2008-01-11T19:34:00Z

64.22.228.134: /* See also */

{{Merge|Bullshido|date=September 2007}}
{{Unreferenced|date=January 2007}} {{expert}}'''Neo-ninja''', sometimes used in conjunction with the term ''Gendai Ninpo'', refers to modern [[martial arts]] schools which claim to teach elements of the historic [[ninja]] of [[Japan]], or base their school's philosophy upon traits attributed to the historic ninja of Japan.

Among Neo-ninja schools there is a lot of variety. Most schools teach eclectic curricula from a variety of different cultures and sources. Some of these schools are clear about the mixed provenance of their history and teachings. Others attempt to obscure the sources of their teachings with an aura of mysticism. Many neo-ninja schools came into being in the 1980s during the "ninja boom."

== See also ==
* [[Ashida Kim]]
* [[Count Dante]]
* [[Frank Dux]]
* [[Rick Tew]]
* [[Glen Levy]]
* [[McDojo]]
* [[Ninjutsu]]
[http://www.neo-ninja.com Neo-Ninja]

[[Category:Ninjutsu]]
[[Category:Martial arts terms]]

{{martialart-term-stub}}

Neo-ninja

2008-01-11T15:13:30Z

64.22.228.134: /* See also */

{{Merge|Bullshido|date=September 2007}}
{{Unreferenced|date=January 2007}} {{expert}}'''Neo-ninja''', sometimes used in conjunction with the term ''Gendai Ninpo'', refers to modern [[martial arts]] schools which claim to teach elements of the historic [[ninja]] of [[Japan]], or base their school's philosophy upon traits attributed to the historic ninja of Japan.

Among Neo-ninja schools there is a lot of variety. Most schools teach eclectic curricula from a variety of different cultures and sources. Some of these schools are clear about the mixed provenance of their history and teachings. Others attempt to obscure the sources of their teachings with an aura of mysticism. Many neo-ninja schools came into being in the 1980s during the "ninja boom."

== See also ==
* [[Ashida Kim]]
* [[Count Dante]]
* [[Frank Dux]]
* [[Rick Tew]]
* [[McDojo]]
* [[Ninjutsu]]
[http://www.neo-ninja.com Neo-Ninja]

[[Category:Ninjutsu]]
[[Category:Martial arts terms]]

{{martialart-term-stub}}

Robin Hood and the Butcher

2007-09-11T13:58:46Z

64.22.228.134:

'''Robin Hood and the Butcher''' is [[Child ballad]] 122. It may have been derived from the similar ''[[Robin Hood and the Potter]]''.

==Synopsis==

[[Robin Hood]] meets with a butcher. In some variants, he fights with him. He always buys his goods and goes into Nottingham, where he sells the meat at ridiculously low prices. The other butchers suspect that he is a prodigal, wasting his inheritance. They invite him to the sheriff's, where their guild is feasting. The [[Sheriff of Nottingham#The Robin Hood stories|sheriff]] asks if he has more animals to sell. Robin takes him to Sherwood and shows him the deer, and then summons his band by his horn.

Robin robs him of his gold and sends him home, saying that his wife's hospitality was all that saved his head.

==Adaptations==
This tale has reappeared in many books of Robin Hood, including [[Howard Pyle]]'s ''Merry Adventures of Robin Hood'', although the threat to kill the sheriff at the end was often omitted.
==External links==
*[http://www.sacred-texts.com/neu/eng/child/ch122.htm ''Robin Hood and the Butcher'']
*[http://www.bartleby.com/243/119.html ''Robin Hood and the Butcher'']
*[http://www.literaturepage.com/read/robinhood-52.html Adaptation] by [[Howard Pyle]]
*[http://www.mainlesson.com/display.php?author=marshall&book=robin&story=butcher Adaptation for children]

[[Category:Child Ballads]]
[[Category:Robin Hood ballads]]

Generating function

2006-10-25T16:29:44Z

64.22.228.134: /* A more detailed example — Fibonacci numbers */

In [[mathematics]] a '''generating function''' is a [[formal power series]] whose coefficients encode information about a [[sequence]] ''a''''n'' that is indexed by the [[natural number]]s.

There are various types of generating functions, including '''ordinary generating functions''', '''exponential generating functions''', '''Lambert series''', '''Bell series''', and '''Dirichlet series'''; definitions and examples are given below. Every sequence has a generating function of each type. The particular generating function that is most useful in a given context will depend upon the nature of the sequence and the details of the problem being addressed.

Generating functions are often expressed in [[closed form]] as functions of a formal argument ''x''. Sometimes a generating function is evaluated at a specific value of ''x''. However, it must be remembered that generating functions are formal power series, and they will not necessarily [[Convergent series|converge]] for all values of ''x''.

==Definitions==

:''A generating function is a clothesline on which we hang up a sequence of numbers for display.''
:— [[Herbert Wilf]], ''[http://www.math.upenn.edu/~wilf/DownldGF.html Generatingfunctionology]'' (1994)

===Ordinary generating function===

The ''ordinary generating function'' of a sequence ''a''''n'' is

:<math>G(a_n;x)=\sum_{n=0}^{\infty}a_nx^n.</math>

When ''generating function'' is used without qualification, it is usually taken to mean an ordinary generating function.

If ''a''''n'' is the [[probability mass function]] of a [[discrete random variable]], then its ordinary generating function is called a [[probability-generating function]].

The ordinary generating function can be generalised to sequences with multiple indexes. For example, the ordinary generating function of a sequence ''a''''m,n'' (where ''n'' and ''m'' are natural numbers) is

:<math>G(a_{m,n};x,y)=\sum_{m,n=0}^{\infty}a_{m,n}x^my^n.</math>

===Exponential generating function===

The ''exponential generating function'' of a sequence ''a''''n'' is

:<math>EG(a_n;x)=\sum _{n=0}^{\infty} a_n \frac{x^n}{n!}.</math>

===Poisson generating function===

The ''Poisson generating function'' of a sequence ''a''''n'' is

:<math>PG(a_n;x)=\sum _{n=0}^{\infty} a_n e^{-x} \frac{x^n}{n!}.</math>

===Lambert series===

The ''[[Lambert series]]'' of a sequence ''a''''n'' is

:<math>LG(a_n;x)=\sum _{n=1}^{\infty} a_n \frac{x^n}{1-x^n}.</math>

Note that in a Lambert series the index ''n'' starts at 1, not at 0.

===Bell series===

The [[Bell series]] of an [[arithmetic function]] ''f''(''n'') and a prime ''p'' is

:<math>f_p(x)=\sum_{n=0}^\infty f(p^n)x^n.</math>

===Dirichlet series generating functions===

[[Dirichlet series]] are often classified as generating functions, although they are not strictly formal power series. The ''Dirichlet series generating function'' of a sequence ''a''''n'' is

:<math>DG(a_n;s)=\sum _{n=1}^{\infty} \frac{a_n}{n^s}.</math>

The Dirichlet series generating function is especially useful when ''a''''n'' is a [[multiplicative function]], when it has an [[Euler product]] expression in terms of the function's Bell series

:<math>DG(a_n;s)=\prod_{p} f_p(p^{-s})\,.</math>

If ''a''''n'' is a [[Dirichlet character]] then its Dirichlet series generating function is called a [[Dirichlet L-series]].

===Polynomial sequence generating functions===

The idea of generating functions can be extended to sequences of other objects. Thus, for example, polynomial sequences of [[binomial type]] are generated by

:<math>e^{xf(t)}=\sum_{n=0}^\infty {p_n(x) \over n!}t^n</math>

where ''p''''n''(''x'') is a sequence of polynomials and ''f''(''t'') is a function of a certain form. [[Sheffer sequence]]s are generated in a similar way. See the main article [[generalized Appell polynomials]] for more information.

==Examples==

Generating functions for the sequence of [[square number]]s ''a''''n'' = ''n''2 are:

===Ordinary generating function===
:<math>G(n^2;x)=\sum_{n=0}^{\infty}n^2x^n=\frac{x(x+1)}{(1-x)^3}</math>

===Exponential generating function===
:<math>EG(n^2;x)=\sum _{n=0}^{\infty} \frac{n^2x^n}{n!}=x(x+1)e^x</math>

===Bell series===
:<math>f_p(x)=\sum_{n=0}^\infty p^{2n}x^n=\frac{1}{1-p^2x}</math>

===Dirichlet series generating function===
:<math>DG(n^2;s)=\sum_{n=1}^{\infty} \frac{n^2}{n^s}=\zeta(s-2)</math>

==Another example==
Generating functions can be created by extending simpler generating functions. For example, starting with

:<math>G(1;x)=\sum_{n=0}^{\infty} x^n = \frac{1}{1-x}</math>

and replacing <math>x</math> with <math>2x</math>, we obtain

:<math>G(1;2x)=\frac{1}{1-2x} = 1+(2x)+(2x)^2+\cdots+(2x)^n+\cdots=G(2^n;x).</math>

== A more detailed example — Fibonacci numbers ==

Consider the problem of finding a closed formula for the [[Fibonacci number]]s ''F''''n'' defined by ''F''0 = 0, ''F''1 = 1, and ''F''''n'' = ''F''''n''−1 + ''F''''n''−2 for ''n'' ≥ 2. We form the ordinary generating function

:<math>
f = \sum_{n \ge 0} F_n x^n
</math>

for this sequence. The generating function for the sequence (''F''''n''−1) is ''xf'' and that of (''F''''n''−2) is ''x''2''f''. From the recurrence relation, we therefore see that the power series ''xf'' + ''x''2''f'' agrees with ''f'' except for the first two coefficients. Taking these into account, we find that

:<math>
f = xf + x^2 f + x . \,\!
</math>

(This is the crucial step; recurrence relations can almost always be translated into equations for the generating functions.) Solving this equation for ''f'', we get

:<math>
f = \frac{x} {1 - x - x^2} .
</math>

The denominator can be factored using the [[golden ratio]] φ1 = (1 + √5)/2 and φ2 = (1 − √5)/2, and the technique of [[partial fraction decomposition]] yields

:<math>
f = \frac{1 / \sqrt{5}} {1+\phi_1 x} - \frac{1/\sqrt{5}} {1- \phi_2 x} .
</math>

These two formal power series are known explicitly because they are [[geometric series]]; comparing coefficients, we find the explicit formula

:<math>
F_n = \frac{1} {\sqrt{5}} (\phi_1^n - \phi_2^n).
</math>

==Applications==

Generating functions are used to

* Find [[recurrence relation]]s for sequences – the form of a generating function may suggest a recurrence formula.
* Find relationships between sequences – if the generating functions of two sequences have a similar form, then the sequences themselves are probably related.
* Explore the asymptotic behaviour of sequences.
* Prove identities involving sequences.
* Solve [[enumeration]] problems in [[combinatorics]].
* Evaluate infinite sums.

==Other generating functions==
Examples of [[polynomial sequence]]s generated by more complex generating functions include:

* [[Difference polynomials]]
* [[Generalized Appell polynomials]]
* [[Q-difference polynomial]]s

==See also==
*[[Moment-generating function]]
*[[Probability-generating function]]
*[[Stanley's reciprocity theorem]]

==References==
* Herbert S. Wilf, ''[http://www.math.upenn.edu/%7Ewilf/DownldGF.html Generatingfunctionology (Second Edition)]'' (1994) Academic Press. ISBN 0-12-751956-4.

* Donald E. Knuth, ''The Art of Computer Programming, Volume 1 Fundamental Algorithms (Third Edition)'' Addison-Wesley. ISBN 0-201-89683-4. Section 1.2.9: Generating Functions, pp.87–96.

* Ronald L. Graham, Donald E. Knuth, Oren Parashnik, ''Concrete Mathematics. A foundation for computer science (Second Edition)'' Addison-Wesley. ISBN 0-201-55802-5. Chapter 7: Generating Functions, pp. 320–380

==External links==
* [http://www.cut-the-knot.org/ctk/GeneratingFunctions.shtml Generating Functions, Power Indices and Coin Change] at [[cut-the-knot]]
* [http://www.math.upenn.edu/~wilf/gfologyLinked2.pdf Generatingfunctionology (PDF)]

[[Category:Combinatorics]]
[[Category:Exponentials]]

[[de:Erzeugende Funktion]]
[[fr:Fonction génératrice]]
[[ko:생성 함수]]
[[it:Funzione generatrice]]
[[he:פונקציה יוצרת]]
[[pl:Funkcja tworząca]]
[[ru:Производящая функция]]
[[uk:Генератриса]]