title: Adhesion

text: The interplay of molecular scale mechanisms and hierarchical surface structures is known to result in high levels of static friction and bonding between pairs of surfaces. Technologically advanced adhesive devices sometimes make use of microstructures on surfaces, such as tightly packed periodic posts. These are biomimetic technologies inspired by the adhesive abilities of the feet of various arthropods and vertebrates (most notably, geckos). By intermixing periodic breaks into smooth, adhesive surfaces, the interface acquires valuable crack-arresting properties. Because crack initiation requires much greater stress than does crack propagation, surfaces like these are much harder to separate, as a new crack has to be restarted every time the next individual microstructure is reached.


title: Adhesion

text: Hysteresis, in this case, refers to the restructuring of the adhesive interface over some period of time, with the result being that the work needed to separate two surfaces is greater than the work that was gained by bringing them together (W > γ + γ). For the most part, this is a phenomenon associated with diffusive bonding. The more time is given for a pair of surfaces exhibiting diffusive bonding to restructure, the more diffusion will occur, the stronger the adhesion will become. The aforementioned reaction of certain polymer-on-polymer surfaces to ultraviolet radiation and oxygen gas is an instance of hysteresis, but it will also happen over time without those factors.


title: Adhesion

text: In addition to being able to observe hysteresis by determining if W > γ + γ is true, one can also find evidence of it by performing “stop-start” measurements. In these experiments, two surfaces slide against one another continuously and occasionally stopped for some measured amount of time. Results from experiments on polymer-on-polymer surfaces show that if the stopping time is short enough, resumption of smooth sliding is easy. If, however, the stopping time exceeds some limit, there is an initial increase of resistance to motion, indicating that the stopping time was sufficient for the surfaces to restructure.


title: Adhesion

text: Some atmospheric effects on the functionality of adhesive devices can be characterized by following the theory of surface energy and interfacial tension. It is known that γ = (1/2)W = (1/2)W. If γ is high, then each species finds it favorable to cohere while in contact with a foreign species, rather than dissociate and mix with the other. If this is true, then it follows that when the interfacial tension is high, the force of adhesion is weak, since each species does not find it favorable to bond to the other. The interfacial tension of a liquid and a solid is directly related to the liquid's wettability (relative to the solid), and thus one can extrapolate that cohesion increases in non-wetting liquids and decreases in wetting liquids. One example that verifies this is polydimethyl siloxane rubber, which has a work of self-adhesion of 43.6 mJ/m in air, 74 mJ/m in water (a nonwetting liquid) and 6 mJ/m in methanol (a wetting liquid).


title: Adhesion

text: This argument can be extended to the idea that when a surface is in a medium with which binding is favorable, it will be less likely to adhere to another surface, since the medium is taking up the potential sites on the surface that would otherwise be available to adhere to another surface. Naturally this applies very strongly to wetting liquids, but also to gas molecules that could adsorb onto the surface in question, thereby occupying potential adhesion sites. This last point is actually fairly intuitive: Leaving an adhesive exposed to air too long gets it dirty, and its adhesive strength will decrease. This is observed in the experiment: when mica is cleaved in air, its cleavage energy, W or W, is smaller than the cleavage energy in vacuum, W, by a factor of 13.


title: Adhesion

text: Lateral adhesion is the adhesion associated with sliding one object on a substrate such as sliding a drop on a surface. When the two objects are solids, either with or without a liquid between them, the lateral adhesion is described as friction. However, the behavior of lateral adhesion between a drop and a surface is tribologically very different from friction between solids, and the naturally adhesive contact between a flat surface and a liquid drop makes the lateral adhesion in this case, an individual field. Lateral adhesion can be measured using the centrifugal adhesion balance (CAB), which uses a combination of centrifugal and gravitational forces to decouple the normal and lateral forces in the problem.


title: Montgolfier brothers

text: The Montgolfier brothers – Joseph-Michel Montgolfier (; 26 August 1740 – 26 June 1810) and Jacques-Étienne Montgolfier (; 6 January 1745 – 2 August 1799) – were aviation pioneers, balloonists and paper manufacturers from the commune Annonay in Ardèche, France. They invented the Montgolfière-style hot air balloon, globe aérostatique, which launched the first confirmed piloted ascent by humans in 1783, carrying Jacques-Étienne. Joseph-Michel also invented the self-acting hydraulic ram (1796) and Jacques-Étienne founded the first paper-making vocational school. Together, the brothers invented a process to manufacture transparent paper.


title: Montgolfier brothers

text: Joseph-Michel and Jacques-Étienne Montgolfier were born into a family of paper manufacturers. Their parents were Pierre Montgolfier (1700–1793) and Anne Duret (1701–1760), who had 16 children. Pierre Montgolfier established his eldest son, Raymond (1730–1772), as his successor.


title: Montgolfier brothers

text: Joseph-Michel was the 12th child. Described as a maverick and dreamer, he was impractical in terms of business and personal affairs. Étienne was the 15th child, had a much more even and businesslike temperament and was sent to Paris to train as an architect. After the sudden and unexpected death of Raymond in 1772, he was recalled to Annonay to run the family business. In the subsequent 10 years, Étienne applied his talent for technical innovation to the family business of paper making, which then as now was a high-tech industry. He succeeded in incorporating the latest Dutch innovations of the day into the family mills.


title: Montgolfier brothers

text: Of the two brothers, it was Joseph who was first interested in aeronautics; as early as 1775 he built parachutes, and once jumped from the family house. He first contemplated building machines when he observed laundry drying over a fire incidentally form pockets that billowed upwards. Joseph made his first definitive experiments in November 1782 while living in Avignon. He reported some years later that he was watching a fire one evening while contemplating one of the great military issues of the day—an assault on the fortress of Gibraltar, which had proved impregnable from both sea and land. Joseph mused on the possibility of an air assault using troops lifted by the same force that was lifting the embers from the fire. He believed that the smoke itself was the buoyant part and contained within it a special gas, which he called "Montgolfier Gas", with a special property he called levity, which is why he preferred smoldering fuel.


title: Montgolfier brothers

text: Joseph then built a box-like chamber 1×1×1.3 m (3 ft by by 4 ft) out of very thin wood, and covered the sides and top with lightweight taffeta cloth. He crumpled and lit some paper under the bottom of the box. The contraption quickly lifted off its stand and collided with the ceiling.


title: Montgolfier brothers

text: Joseph recruited his brother to balloon building by writing, "Get in a supply of taffeta and of cordage, quickly, and you will see one of the most astonishing sights in the world." The two brothers built a similar device, scaled up by three (so 27 times greater in volume). On 14 December 1782 they did their very first test flight, lighting with wool and hay, and the lifting force was so great, that they lost control of their craft. The device floated nearly two kilometers (about 1.2 mi) and was destroyed after landing by the "indiscretion" of passersby.


title: Montgolfier brothers

text: To make a public demonstration and to claim its invention the brothers constructed a globe-shaped balloon of sackcloth tightened with three thin layers of paper inside. The envelope could contain nearly 790 m³ (28,000 cubic feet) of air and weighed 225 kg (500 lb). It was constructed of four pieces (the dome and three lateral bands) and held together by 1,800 buttons. A reinforcing fish net of cord covered the outside of the envelope.


title: Montgolfier brothers

text: On 4 June 1783, they flew the balloon at Annonay in front of a group of dignitaries from the "états ″particuliers″". The flight covered 2 km (1.2 mi), lasted 10 minutes, and had an estimated altitude of 1,600–2,000 m (5,200–6,600 ft). Word of their success quickly reached Paris. Étienne went to the capital to make further demonstrations and to solidify the brothers' claim to the invention of flight. Joseph, given his unkempt appearance and shyness, remained with the family. Étienne was "the epitome of sober virtues ... modest in clothes and manner..."


title: Montgolfier brothers

text: In collaboration with the wallpaper manufacturer Jean-Baptiste Réveillon, Étienne constructed a envelope of taffeta coated with a varnish of alum for fireproofing. The balloon was sky blue and decorated with golden flourishes, signs of the zodiac, and suns. The design showed the intervention of Réveillon. The next test was on 11 September from the grounds of "la Folie Titon", close to Réveillon's house. There was some concern about the effects of flight into the upper atmosphere on living creatures. The king proposed to launch two convicted criminals, but it is most likely that the inventors decided to send a sheep, a duck, and a rooster aloft first.


title: Montgolfier brothers

text: On 19 September 1783, the "Aérostat Réveillon" was flown with the first living beings in a basket attached to the balloon: a sheep called Montauciel ("Climb-to-the-sky"), a duck and a rooster. The sheep was believed to have a reasonable approximation of human physiology. The duck was expected to be unharmed by being lifted and was included as a control for effects created by the aircraft rather than the altitude. The rooster was included as a further control as it was a bird that did not fly at high altitudes. The demonstration was performed at the royal palace in Versailles, before King Louis XVI of France and Queen Marie Antoinette and a crowd. The flight lasted approximately eight minutes, covered two miles (3 km), and obtained an altitude of about . The craft landed safely after flying.


title: Montgolfier brothers

text: Since the animals survived, the king allowed flights with humans. Again in collaboration with Réveillon, Étienne built a balloon for the purpose of making flights with humans. It was about 23 m (75 feet) tall and about 15 m (50 feet) in diameter. Réveillon supplied rich decorative touches of gold figures on a deep blue background, including fleur-de-lis, signs of the zodiac, and suns with Louis XVI's face in the center interlaced with the royal monogram in the central section. Red and blue drapery and golden eagles were at the base of the balloon. Étienne Montgolfier was the first human to lift off the Earth in a balloon, making a tethered test flight from the yard of the Réveillon workshop in the Faubourg Saint-Antoine, most likely on 15 October 1783. A little while later on that same day, physicist Pilâtre de Rozier became the second to ascend into the air, to an altitude of , which was the length of the tether.


title: Montgolfier brothers

text: On 21 November 1783, the first free flight by humans was made by Pilâtre de Rozier, together with an army officer, the marquis d'Arlandes. The flight began from the grounds of the Château de la Muette close to the Bois de Boulogne park in the western outskirts of Paris. They flew about above Paris for a distance of nine kilometers. After 25 minutes, the balloon landed between the windmills, outside the city ramparts, on the Butte-aux-Cailles. Enough fuel remained on board at the end of the flight to have allowed the balloon to fly four to five times as far. However, burning embers from the fire were scorching the balloon fabric and had to be daubed out with sponges. As it appeared it could destroy the balloon, Pilâtre took off his coat to stop the fire.


title: Montgolfier brothers

text: The early flights made a sensation. Numerous engravings commemorated the events. Chairs were designed with balloon backs, and mantel clocks were produced in enamel and gilt-bronze replicas set with a dial in the balloon. One could buy crockery decorated with naive pictures of balloons.


title: Montgolfier brothers

text: In December 1783, father Pierre Montgolfier was elevated to the nobility and the hereditary appellation of de Montgolfier by King Louis XVI of France.


title: Montgolfier brothers

text: Some claim that the hot air balloon was invented about 74 years earlier by the Brazilian/Portuguese priest Bartolomeu de Gusmão. A description of his invention was published in 1709(?) in Vienna, and another one was found in the Vatican in about 1917.


title: Montgolfier brothers

text: However, this claim is not generally recognized by aviation historians outside the Portuguese-speaking community, in particular the Fédération Aéronautique Internationale.


title: Montgolfier brothers

text: On 1 December 1783, a few months after the Montgolfiers' first flight, Jacques Alexandre César Charles rose to an altitude of about near Paris in a hydrogen-filled balloon he had developed.


title: Montgolfier brothers

text: In early 1784, the Flesselles balloon, named after the unfortunate Jacques de Flesselles, later to be an early casualty at the Bastille, gave a rough landing to its passengers.


title: Montgolfier brothers

text: In June 1784, the "Gustave" (a hot air balloon christened "La Gustave" in honour of King Gustav III of Sweden's visit to Lyon) saw the first female aeronaut, Élisabeth Thible.


title: Montgolfier brothers

text: Both brothers invented a process to manufacture transparent paper looking like vellum, reproducing the technique of the English, followed by the papermakers Johannot and Réveillon.


title: Montgolfier brothers

text: In 1796, Joseph Michel Montgolfier invented the first self-acting hydraulic ram, a water pump to raise water for his paper mill at Voiron. In 1772, the British clockmaker John Whitehurst had invented its precursor, the "pulsation engine".


title: Montgolfier brothers

text: In 1799, Etienne de Montgolfier died on the way from Lyon to Annonay. His son-in-law, Barthélémy Barou de la Lombardière de Canson (1774–1859), succeeded him as the head of the company, thanks to his marriage with Alexandrine de Montgolfier. The company became "Montgolfier et Canson" in 1801, then "Canson-Montgolfier" in 1807. In 1810, Joseph-Michel died in Balaruc-les-Bains.


title: Montgolfier brothers

text: The Montgolfier Company in Annonay still exists under the name Canson. It produces fine art papers, school drawing papers and digital fine art and photography papers sold in 150 countries.


title: Montgolfier brothers

text: In 1983, the Montgolfier brothers were inducted into the International Air & Space Hall of Fame at the San Diego Air & Space Museum.


title: Latavius Murray

text: Latavius Rashard Murray (born January 18, 1990) is an American football running back for the Denver Broncos of the National Football League (NFL). He played college football at UCF and was drafted by the Oakland Raiders in the sixth round of the 2013 NFL Draft. He was also a member of the Minnesota Vikings, New Orleans Saints, and Baltimore Ravens.


title: Latavius Murray

text: Born in Titusville, Florida, Murray attended Onondaga Central High School in Onondaga, New York, where he was a three-sport athlete in football, basketball, and track. In football, Murray was All-league and All-Central New York selection in three straight seasons. In his sophomore year, he was third-team All-state honoree following a 1,609-yard, 14-touchdown season. He garnered first-team All-state honors as a junior, rushing for 2,030 yards and 30 touchdowns. In his final year, he was named the 2007 Gatorade Football Player of the Year in the state of New York after rushing for 2,194 yards with 28 touchdowns on offense, while also recording 78 tackles, three forced fumbles and two interceptions on defense. He also was named as the Class D Player of the Year and First-team All-State by the NYSSWA.


title: Latavius Murray

text: Regarded as a three-star recruit, Murray was ranked as the No. 5 prospect in the state of New York by "Rivals.com", No. 6 according to "Scout.com". He chose UCF over scholarship offers from Boston College, Maryland, and Syracuse, among others.


title: Latavius Murray

text: He made his collegiate debut against South Carolina State and had 43 rushing yards and two touchdowns. In his freshman season, he finished with 132 rushing yards and three rushing touchdowns. Murray tore his ACL during the offseason after his freshman year while playing basketball.


title: Latavius Murray

text: After redshirting in 2009, he returned to the Knights' backfield in 2010. On November 20, against Tulane, he had his best game of the season with 146 rushing yards and a touchdown. On December 4, against SMU, he finished with 94 rushing yards and 21 receiving yards in a game with his first collegiate receiving touchdown. In his redshirt sophomore season, he was named Conference USA Championship MVP and also was named AutoZone Liberty Bowl MVP for his performance against Georgia in which he rushed for 104 yards and scored the game-winning touchdown. Overall, in the 2010 season, he finished with 637 rushing yards, 11 rushing touchdowns, five receptions, 47 receiving yards, and one receiving touchdown.


title: Latavius Murray

text: He started his junior season with 36 rushing yards and two rushing touchdowns against Charleston Southern. In the next game against Boston College, he had 72 rushing yards and a touchdown. He was mostly held in check up to the end of the regular season. On November 19, against East Carolina, he had 87 rushing yards and a touchdown. In the last game of the season against UTEP, he had a season-high 233 rushing yards with two rushing touchdowns. Following the conclusion of his junior season, he was selected as the team's MVP and offensive player of the year.


title: Latavius Murray

text: In his senior season, he was an All-C-USA First-team selection and was named to Phil Steele's All-C-USA First-team. He was named to the College Football Performance Awards All-Purpose Trophy Watch List and also was selected to the College Football Performance Awards Special Teams Watch List. He was named to the Doak Walker Award Watch List. On August 30, 2012, he started the season with 108 rushing yards and a touchdown against Akron. On October 20, he started a four-game stretch where he recorded 192 yards and two touchdowns, 156 yards and three touchdowns, 155 yards and two touchdowns, and 117 rushing yards and a rushing touchdown in those games. Overall, in his last season with the Knights, he had 1,106 rushing yards, 15 rushing touchdowns, 27 receptions, 231 receiving yards, and four receiving touchdowns. He finished his college career with a total of 2,424 rushing yards, 37 rushing touchdowns, 50 receptions, 524 receiving yards and 6 receiving touchdowns.


title: Latavius Murray

text: Murray was not invited to the NFL Combine, but garnered much attention with an impressive performance at Central Florida's Pro Day. Murray weighed in at 6-foot-2 5/8 and 223 pounds, ran the 40-yard dash in 4.4 and 4.38 seconds, registered a 10-foot-4 broad jump and a 36-inch vertical jump, ran 4.36 seconds in the short shuttle and 6.81 seconds in the 3-cone.


title: Latavius Murray

text: Murray was selected by the Oakland Raiders with the 181st overall pick in the sixth round of the 2013 NFL Draft. He was the 15th running back to be selected in that year's draft. The Raiders signed Murray to a four-year, $2.26 million contract on June 6, 2013. It also included $106,200 guaranteed and a signing bonus of $106,200.


title: Latavius Murray

text: On August 27, 2013, before the start of the regular season, Murray was placed on injured reserve, ending his rookie season before it started.


title: Latavius Murray

text: After being third on the depth chart for the first half of the season behind veterans Darren McFadden and Maurice Jones-Drew, the Raiders turned to Murray in Week 11 to provide a spark after ineffectiveness by McFadden and Jones-Drew all year. He responded by totaling 59 yards on seven carries against the San Diego Chargers. On November 20, 2014, he finished with four carries for 112 rushing yards and two rushing touchdowns, marking his first career touchdown against the Kansas City Chiefs. It also marked the first rushing touchdown the Chiefs defense allowed all season and his 90-yard touchdown marked the longest rush for the Raiders that year. The solid performance by Murray contributed to the Raiders' first victory of the 2014 season. After having success on his first three attempts, he suffered a concussion on his fourth carry and was taken out of the game.


title: Latavius Murray

text: Murray returned to play against the San Francisco 49ers in Week 14 and finished the 24–13 victory with 23 carries for 76 rushing yards. In the next game, he earned his first NFL start against the Chiefs and had 12 rushing attempts for 59 yards. In Week 16, he gained 86 yards on 16 carries and had his second consecutive start against the Buffalo Bills. Murray remained the starting running back for the last three games of the season and finished his first year with 82 carries, 424 rushing yards, and two rushing touchdowns in 15 games.


title: Latavius Murray

text: Murray entered the season as the Raiders' number one tailback and was expected by the Raiders to receive the majority of the carries after the retirement of Maurice Jones-Drew and the departure of Darren McFadden. As expected, he began the season as the Raiders' starting running back and had 11 attempts for 44 yards in the season-opening 33–13 loss to the Cincinnati Bengals. Two weeks later, Murray ran for a career-high 139 yards and a touchdown on 26 carries in a 27–20 win over the Cleveland Browns. On November 1, against the New York Jets, he had 113 rushing yards in the 34–20 victory.


title: Latavius Murray

text: On Christmas Eve, Murray became the first Raider to reach the 1,000-yard mark rushing, since Darren McFadden did in 2010. His performance of 79 yards on 19 carries, 38 yards on five receptions and a rushing touchdown, helped edge a victory over the San Diego Chargers with a final score of 23–20 in overtime.


title: Latavius Murray

text: Overall, Murray finished the 2015 season with 1,066 rushing yards and six touchdowns along with 41 receptions for 232 yards.


title: Latavius Murray

text: Murray started the season off with a rushing touchdown in three straight games against the New Orleans Saints, Atlanta Falcons, and Tennessee Titans. On October 23, against the Jacksonville Jaguars, he had 59 rushing yards and two touchdowns. On November 6, in a 30–20 victory over the Denver Broncos, he had 114 rushing yards and three touchdowns. In a 38–24 victory over the Buffalo Bills on December 4, he ran for 82 rushing yards and two touchdowns. In a 21–13 loss to the Kansas City Chiefs four days later, he had his third straight game with a rushing touchdown to go along with 103 rushing yards.


title: Latavius Murray

text: Murray finished the regular season playing in 14 games and rushing for 788 yards and a career-high 12 rushing touchdowns. On January 7, Murray made his playoff debut in the against the Houston Texans. In the 27–14 road loss, he finished with 39 rushing yards and his first NFL postseason rushing touchdown.


title: Latavius Murray

text: On March 16, 2017, Murray signed a three-year contract with the Minnesota Vikings. In his opening statement to Vikings fans, Murray stated on his Instagram account: "There wasn't a thought in my mind to try and wear or ask for the No. 28. I have too much respect for Adrian Peterson and so much respect for what he's done and what he means to this organization." During his first press conference as a Viking, Murray announced that he would be wearing #25 in honor of his best friend, who had died in 2016. On March 22, 2017, it was revealed Murray underwent ankle surgery.


title: Latavius Murray

text: On September 11, 2017, in the season opener against the New Orleans Saints, Murray had two rushes for six yards in his Vikings debut, ultimately being out-shined by rookie Dalvin Cook. However, Cook tore his ACL in a game against the Detroit Lions, creating an opportunity for Murray. During Week 7 against the Baltimore Ravens, Murray rushed for 117 yards and a touchdown as the Vikings won 24–16. On November 19 against the Los Angeles Rams, he ran for 95 yards and two touchdowns in the 24–7 victory. In the regular season finale against the Chicago Bears, Murray had 111 rushing yards and two touchdowns in the 23–10 victory.


title: Latavius Murray

text: Murray finished his first season with the Vikings with 842 rushing yards and eight touchdowns along with 15 receptions for 103 yards. The Vikings finished atop the NFC North with a 13–3 record and made the playoffs as the #2-seed. In the 29–24 victory over the New Orleans Saints in the Divisional Round, Murray ran for 50 yards and a touchdown. In the 38–7 road loss to the Philadelphia Eagles in the , he was limited to 18 rushing yards on six carries.


title: Latavius Murray

text: In the first five games of the 2018 season, Murray totaled 30 carries for 106 yards and nine receptions for 60 yards in a limited role. In Week 6, against the Arizona Cardinals, he rushed for a career-high 155 yards and a touchdown in a 27–17 victory. In the next game, a 37–17 victory over the New York Jets, he had 69 rushing yards and two touchdowns.


title: Latavius Murray

text: Murray finished the 2018 season with 578 rushing yards and six touchdowns along with 22 receptions for 141 yards.


title: Latavius Murray

text: Murray made his Saints debut in the season opener against the Houston Texans, rushing six times for 43 yards and a 30-yard touchdown in the narrow 30–28 victory. During Week 7 against the Chicago Bears, he rushed for 119 yards and two touchdowns in a 36–25 road victory. In the next game against the Arizona Cardinals, Murray rushed 21 times for 102 yards and a touchdown and caught nine passes for 55 yards and a touchdown in the 31–9 win.


title: Latavius Murray

text: Murray finished his first season with the Saints with 637 rushing yards and five touchdowns along with 34 receptions for 235 yards and a touchdown.


title: Latavius Murray

text: In Week 4 against the Detroit Lions, Murray rushed for 64 yards and his first two rushing touchdowns of the season during the 35–29 win. In Week 12 against the Denver Broncos, he had 19 carries for 124 rushing yards and two rushing touchdowns in the 31–3 victory. He was placed on the reserve/COVID-19 list by the team on January 2, 2021, and activated on January 6. Overall, Murray finished the 2020 season with 146 carries for 656 rushing yards and four rushing touchdowns to go along with 23 receptions for 176 receiving yards and one receiving touchdown.


title: Latavius Murray

text: On September 10, 2021, the Baltimore Ravens signed Murray following injuries to J. K. Dobbins, Justice Hill, and Gus Edwards. In his debut against the Las Vegas Raiders, he had 28 yards and a touchdown on 10 carries, but the Ravens lost in overtime 27–33. He was named the starter in Week 4 against the Denver Broncos. In the Week 18 regular season finale against the Pittsburgh Steelers, he had 16 carries for 150 rushing yards and a touchdown in the 16–13 loss. He finished the 2021 season with 119 carries for 501 rushing yards and six rushing touchdowns.


title: Latavius Murray

text: Murray was signed to the Saints practice squad on September 13, 2022. He was elevated to the active roster on October 1, 2022.


title: Latavius Murray

text: Murray was signed off the Saints practice squad by the Denver Broncos following a season-ending injury to Javonte Williams.


title: Latavius Murray

text: Murray lives in Florida with his wife and four children. In 2020, he earned a MBA from the Martin J. Whitman School of Management of Syracuse University.


title: Oren Peli

text: Oren Peli (; born January 21, 1970) is an Israeli film director, producer and screenwriter, known for directing the 2007 film "Paranormal Activity".


title: Oren Peli

text: Peli was born in Ramat Gan, Israel, to a Jewish family. At the age of 19, he moved to the United States.


title: Oren Peli

text: Peli began as a computer software programmer, and was one of the developers behind Photon Paint, a bitmap graphics program for the Amiga. He is also credited for developing the networking code for the home console versions of "Mortal Kombat 3", during his work at Sculptured Software.


title: Oren Peli

text: His first film "Paranormal Activity" was inspired by Peli moving into his first house alone and without family nearby. Peli heard creaks and knocks in the night, which laid the groundwork for a film about a family running around with cameras trying to catch what was going on in the house.


title: Oren Peli

text: After the success of "Paranormal Activity", Peli worked with James Wan and Leigh Whannell to develop "Insidious". Peli also produced and wrote the 2012 horror film "Chernobyl Diaries", based on the Chernobyl disaster and on his story "The Diary of Lawson Oxford". The film followed "a group of friends who, while vacationing in Europe, find themselves stranded in the abandoned city of Prypiat, Ukraine only to discover that they are not alone."


title: Oren Peli

text: In 2012, "The River" premiered on ABC, a paranormal/action/horror television series about a group of people on a mission to find a missing TV explorer in the Amazon. Peli co-created the show with Michael R. Perry, who co-wrote "Paranormal Activity 2".


title: Oren Peli

text: Peli is writer and director of "Area 51", a story about three friends who want to discover the secrets of the fabled Area 51. Peli is also the producer of all films in the "Paranormal Activity" franchise and "The Lords of Salem".


title: Janatha Vimukthi Peramuna

text: Janatha Vimukthi Peramuna (JVP; ) is a Marxist–Leninist communist party and a former militant organization in Sri Lanka. The movement was involved in two armed uprisings against the government of Sri Lanka: once in 1971 (SLFP), and another in 1987–89 (UNP). The motive for both uprisings was to establish a socialist state.


title: Janatha Vimukthi Peramuna

text: The JVP was initially a small organisation that became a well-organised party that could influence mainstream politics. Its members campaigned openly for the left-wing coalition government, United Front. Following their disillusion with the coalition, they started an insurrection against the Dominion of Ceylon in early 1971, which intensified following the ban on the party. The military arm the Red Guard captured over 76 police strongholds throughout the island of Ceylon.


title: Janatha Vimukthi Peramuna

text: The JVP entered democratic politics in 1977 when President J.R. Jayewardene released the JVP leader, Rohana Wijeweera, from prison. After the United Front coalition government collapsed, Wijeweera contested the presidential elections in 1982 and obtained 4.16 percent of the votes cast. Before the elections, he had been convicted through the Criminal Justice Commission (CJC) for conspiring to overthrow the state violently. The JVP launched a more organized insurrection for the second time in 1987 after the Indo-Sri Lanka accord was signed.


title: Janatha Vimukthi Peramuna

text: Following Operation Combine and Wijeweera's death, the JVP returned to elections as the National Salvation Front. The surviving JVP members campaigned in the 1994 elections, but eventually withdrew and supported the nationalist opposition party, Sri Lanka Freedom Party. In 2004, it joined the government as a part of the United People's Freedom Alliance and supported the government in its war against the Liberation Tigers of Tamil Eelam (LTTE), but subsequently left the coalition government.


title: Janatha Vimukthi Peramuna

text: Later, it contested under its own national coalition and has since been a third party in overall Sri Lankan politics.


title: Janatha Vimukthi Peramuna

text: The JVP was founded in 1965 to provide a leading force for a Communist revolution in Sri Lanka. In 1965, there were four other leftist political parties: the Lanka Sama Samaja Party (LSSP), established in 1935 as the first political party in Sri Lanka; the Communist Party of Sri Lanka (CPSL), which broke away from the LSSP and formed their own party in 1943 due to differences of opinion on supporting Britain during the 2nd World War; the Mahajana Eksath Peramuna (MEP); and the Peking Left.


title: Janatha Vimukthi Peramuna

text: Since the country's independence, the two main parties, the United National Party (UNP) and the Sri Lanka Freedom Party (SLFP, which broke away from the UNP in 1951), governed the country for eight years each, and the country's economic outlook worsened. According to the JVP's founders, neither party had been able to implement even a single measure to resolve the crisis. The JVP considered the entry of three left parties into the United Front (UF) of Sri Lanka in 1964 as a conscious betrayal of the aspirations of the people and the working class. Inflation, unemployment, and food prices increased despite government efforts to prevent it.


title: Janatha Vimukthi Peramuna

text: Rohana Wijeweera's father was a political activist of the CPSL. During an election campaign in the 1960s, he was severely assaulted by UNP members and was paralysed; Wijeweera was likely emotionally affected, which may have changed his views and caused his hatred against the UNP. When Wijeweera's further education was threatened as a result of his father's incapacitation, the CPSL arranged a scholarship for him to study medicine at the Patrice Lumumba Friendship University in Moscow, where he read the works of Karl Marx, Friedrich Engels, and Lenin, and became a committed Marxist.


title: Janatha Vimukthi Peramuna

text: By this time, the United Socialist Party (USP) was divided into two factions: the Chinese faction and the Soviet faction. Wijeweera broke away from the CPC which was aligned with the USSR and joined the Ceylon Communist Party (Maoist).


title: Janatha Vimukthi Peramuna

text: After a visit to Sri Lanka in 1964, he was not permitted to return to the USSR: his student activism in favour of Maoism while in Moscow displeased the Russians. The Chinese faction was led by Premalal Kumarasiri. Through his father's political activities, Wijeweera contacted Kumarasiri and joined the party's staff and became part of the trade union office.


title: Janatha Vimukthi Peramuna

text: Wijeweera increasingly felt that the Left movement (generally referred to in Sri Lanka as "old left") that existed until then had not produced enough professional revolutionaries and had never made a meaningful effort to educate the masses on Marxism. Workers accepted the words mouthed by the leaders of the "old left" as the final word. He also believed that the leadership of the "old left", aware of this aspect, utilised it to the fullest to blunt workers' militancy. Wijeweera and others decided in mid-1965 to launch a new party that was explicitly revolutionary in character; it was formed without breaking off from other established parties. The cadres engaged themselves in political activities that consisted mainly of trying to increase the political awareness of the working class.


title: Janatha Vimukthi Peramuna

text: Wijeweera felt that one of the more important tasks was to educate the masses politically. After deliberating on the issue, it was decided that an uncomplicated Marxist analysis of the socio-politico-economic problems of the country should be the introductory step. The Marxist analysis was split into five discussions along with five main themes.


title: Janatha Vimukthi Peramuna

text: Throughout the rest of 1968, Wijeweera traveled across the country, conducting political classes for the members of the party. An education camp followed the five basic political classes. Precautions had to be taken to keep this educational camp a secret to avoid alarming the government and the "old left". All conducted by Wijeweera, the classes stretched from 17 to 18 hours a day, interrupted only by meals.


title: Janatha Vimukthi Peramuna

text: By 1971, the JVP established itself as a political party and offered an alternative to those disillusioned with the politics of the other left organizations. Most of the members and supporters of the JVP at the time were young adults. Alarmed at the JVP's political potential and challenge, the government and its leftist allies levelled a variety of slander against it. Many representatives of the "old left" called the JVP members "CIA agents attempting to overthrow the pro-Eastern bloc party".


title: Janatha Vimukthi Peramuna

text: JVP built cells in multiple countries, including South Yemen, Belgium, the UK, and Ba'athist Iraq; South Yemen also promised to hold some weapon supplies; although the manufacturer later said that there was no possible way to supply weapons, the government congratulated the organisation with a letter that read "Revolutionary Greetings".


title: Janatha Vimukthi Peramuna

text: The 1971 uprising led by the JVP was unsuccessful and allegedly claimed nearly 5,000 lives. The JVP drew worldwide attention when it launched an insurrection against the Bandaranaike government in April 1971. Although the insurgents were young, poorly armed, and inadequately trained, they seized and held major areas in the southern and central provinces of Sri Lanka before they were defeated by the security forces. Their attempt to seize power created a major crisis for the government and forced a fundamental reassessment of the nation's security needs. In March 1971, after an accidental explosion in one of the bomb factories, the police found fifty-eight bombs in a hut in Nelundeniya, Kegalle District. Shortly afterward, Wijeweera was arrested and sent to Jaffna Prison, where he remained throughout the revolt. In response to his arrest and the growing pressure of police investigations, other JVP leaders acted immediately, and started the uprising at 11:00 p.m. on 5 April. After two weeks of fighting, the government regained control of all but a few remote areas. In both human and political terms, the cost of the victory was high: an estimated 30,000 insurgents, according to the JVP, many of them in their teens, died in the conflict. The army and police were also widely perceived to have used excessive force. In order to win over an alienated population and to prevent a prolonged conflict, Bandaranaike offered amnesties in May and June 1971, and the top leaders were imprisoned. Wijeweera, who was already in detention at the time of the uprising, was given a twenty-year sentence.


title: Janatha Vimukthi Peramuna

text: The Indian intervention through the Indo-Sri Lanka accord and the plan to divide the island led to the 1987–1989 revolt. The JVP exploited the arrival of the Indian Peace-keeping Force and the widespread nationalist sentiments of large sections of the Sinhalese people to terrorise both the state machinery and sections of civil society that opposed its thinking, which almost overpowered the state. Organised in multiple cells countrywide and mostly based around the capital Kandy in the centre, the JVP murdered probably thousands of people and crippled the country with violently enforced hartals (general strikes) for three years. Government forces captured and killed Wijeweera and his deputy in November 1989 in Colombo; by early 1990 they had killed or imprisoned the remaining JVP politburo and detained an estimated 7,000 suspected JVP members. Although the government won a decisive military victory, there were credible accusations of brutality and extrajudicial methods. The number of deaths during the insurgency is uncertain, as the government was also fighting Tamil insurgent groups at the time. Multiple official and unofficial forces and reports confirm that the death toll exceeded 60,000. In addition, many people took advantage of the chaos to instigate deadly local feuds.


title: Janatha Vimukthi Peramuna

text: What is certain is the methods of death, including necklacing, victims eviscerated and left to die, and even the occasion of eighteen heads arranged around the Alwis pond at the University of Peradeniya, which occurred the day after T.E. Nagahawatte, the Assistant Registrar of the university and a volunteer officer, was killed by two gunmen inside university premises. For genocide studies, it was an example of politicide that happened in a democratic regime, which resulted in the killing of at least 13,000 and 30,000 JVP members and its alleged supporters.


title: Janatha Vimukthi Peramuna

text: The JVP military section which was made up mostly of inadequately trained youths, were responsible for attacks on several locations throughout Ceylon, including on the Jaffna prison, SLAF Ekala and the Wellawaya town in 1971. Later in the 80s, JVP with the assistance of several other militant organisations trained the Patriotic People's Armed Forces. PPAF carried out more well planned attacks such as the attack on the Pallekele detachment. The military section of the JVP in the late 80s were led by the DJV leader Keerthi Vijayabahu.


title: Janatha Vimukthi Peramuna

text: Despite the lack of training they received, the JVP militants were armed with shotguns, wore blue colored uniforms with boots and helmets, carried haystacks, and ammunition. The primary source of funding were bank robberies.


title: Janatha Vimukthi Peramuna

text: During its second insurgency, they were armed with stolen weapons such as AK 47, T 56, and .303 British rifles.


title: Janatha Vimukthi Peramuna

text: The JVP has been internationally affiliated to multiple organisations, some of which were the Palestine Liberation Organization (PLO), the National Liberation Front of Yemen, and the Korean Workers' Party (KWP).


title: Janatha Vimukthi Peramuna

text: In the early 1970s, North Korea backed the JVP by supplying training. As a result, diplomatic connections between Sri Lanka and North Korea were cut off and were not re-established. 18 North Koreans were expelled from the island, but it did not stop their support of the JVP, and Indian patrol boats deployed around the island were attacked by North Korean gunboats that raided the territory. Prior to expulsion, the North Koreans spent 14,000 dollars supporting the movement with propaganda. They also supplied militant equipment and instructions on making explosives and conducting guerrilla warfare.


title: Janatha Vimukthi Peramuna

text: In 2017, the Sri Lankan government imposed UN sanctions on North Korea. The leader of the JVP, Anura Kumara Dissanayaka, criticised the procedure, claiming North Korea is socialist and that Sri Lanka should support it.


title: Janatha Vimukthi Peramuna

text: In 1970 a North Korean trade office in Colombo became an embassy and started its work the same year. While in Sri Lanka, North Korean diplomats cultivated links to the JVP, and the nation helped the group directly through the office. Wijeweera visited North Korea prior to the establishment of the JVP.


title: Janatha Vimukthi Peramuna

text: The JVP sectors before the 1970s were limited to the Arab Socialist Ba'ath Party of Iraq (ASBPI). Wijeweera and Shantha Bandara visited Iraq multiple times in order to meet the members of the ASBPI. Bandara successfully formed the Inter-University Students' Federation to work as a liaison point between the two parties. When the Iran–Iraq War began, a few members of the JVP protested in front of the Iranian embassy. During the second JVP insurgency, the JVP received money from Iraq to fund the Patriotic People's Movement.


title: Janatha Vimukthi Peramuna

text: The Soviet Union began to recognise the JVP in 1978 when it was no longer affiliated to the Chinese Communist Party (CCP). The Soviet Communist Party invited the organisation along with the CPSL to participate in the International Federation of Youths and Students. All financing was provided by the Soviet Union for the parties that visited the meeting upon Soviet invitation.


title: Janatha Vimukthi Peramuna

text: The JVP's ideology changed depending on its leadership or other national and political issues within Sri Lanka or any other influential group. The JVP's mixed ideology was shaped by its origin from Maoism and transition to other forms of Marxism like Guevarism and Ho Chi Minh Thought. In the beginning, it had schisms from internal ideological conflicts.


title: Janatha Vimukthi Peramuna

text: The first five lectures of the JVP based on class and social struggle were about the "failures" of the old left and the "path" for a new left. Wijeweera, who held anti-Indian sentiments, gave lectures against Indian irredentism. The rest of the lectures are based on economy and unemployment.


title: Janatha Vimukthi Peramuna

text: In 1983, the JVP's ideology was modified, as the party foresaw the consequence of inaction against Indian intelligence agencies (particularly the Research and Analysis Wing) infiltrating the national patronage. By this time it developed its own ideology named "Jathika Chintanaya" ().


title: Janatha Vimukthi Peramuna

text: Somawansa Amarasinghe, who subsequently became the leader, modified the JVP from the roots re-socialised with other democratic groups. It refused to be affiliated nationally, but later joined some left-right alliances such as the United National Front. The organisation believes in democracy-based political lines rather than insurrectionist lines it appreciated since its conception. The JVP formed the National People's Power in 2015, which consists of various leftist groups that follow various leftist ideologies such as agrarian socialism, democratic socialism and revolutionary socialism. The current ideology of the group is democracy and anti-imperialism.


title: Janatha Vimukthi Peramuna

text: JVP was not recognised as a political party until its first uprising. The party rejected being a democratic party following the military coup in Indonesia against the Indonesian Communist Party. It complained that the Ceylonese government would try to militarily defeat the group if it stopped arming itself. The government banned the JVP following an attack on the United States high commission in Ceylon. The government blamed the protests that led to the attack on the JVP members, but it was revealed that the attack was conducted by a Maoist organisation.


title: Janatha Vimukthi Peramuna

text: The brief conflict created turmoil in Sri Lanka's national politics and its international relations. Many countries were blamed for supporting the JVP, including the People's Republic of China (China) and North Korea; China denied supporting the party. As a result of the struggle, the UF government denounced the JVP in April 1971, and it became an underground organisation, though it participated in the 1978 local government elections. It refrained from attacking the government as the UF government was already facing persecution.


title: Janatha Vimukthi Peramuna

text: After the 1978 elections, the organisation's reputation among revolutionaries decreased; however, the public began to recognise it, and it quickly gained members. In 1982 the JVP participated in the District Development Council (DDC) elections and the presidential elections; it was the only radical party that contested the DDC elections in 1982.


title: Janatha Vimukthi Peramuna

text: The UNP had introduced the District Development Council as a solution to the ethnic conflict. The Nava Sama Samaja Party (NSSP), CPSL, and the nationalistic SLFP boycotted the elections, but as the JVP contested, it won a couple of seats in the council's elections. Around this time, the Election Commission of Sri Lanka formally recognised the JVP as a legitimate political party.


title: Janatha Vimukthi Peramuna

text: In 1978, the UNP introduced commissions to charge UF members for ignoring or violating human rights in events such as the humiliation, rape, and murder of Premawathie Manamperi. The UNP called JVP members to give evidence against the UF; the UF criticised the procedure, calling it capitalist. Afterwards, the UF members lost their civil ownership, and were not allowed to participate in the 1978 elections. As a result, the Tamil United Liberation Front (TULF) came to become the opposition, which the JVP tried to remove.


title: Janatha Vimukthi Peramuna

text: In 1982, Wijeweera contested the presidential elections. The party expected to win more than 500,000 votes but won only 275,000. Although it received more votes than Colvin R. de Silva, the party was disappointed by the results. The government banned the party again, and JVP membership dropped as people began to doubt its electoral viability.


title: Janatha Vimukthi Peramuna

text: After the ethnic riots, the government denounced the JVP, CPSL, and NSSP to get the UK and US' attention, claiming that the parties were involved in the Black July riots that killed thousands of Tamils. The proscription on the CPSL was lifted due to its Tamil representation, but the JVP continued to be banned.


title: Janatha Vimukthi Peramuna

text: After JVP leadership was eliminated by state repression during the Premadasa government, it was resurrected as a political party joining the mainstream led by Somawansa Amerasinghe – the only surviving member of the decimated JVP politburo. However, the JVP had an internal conflict: JVP supported Chandrika Bandaranaike Kumaranatunga's election campaign after withdrawing their candidate. The JVP contested the presidential elections in 1999 and their candidate Nandana Gunatilleke received 4.08% of the vote. The JVP was contested by the National Salvation Front.


title: Janatha Vimukthi Peramuna

text: The high point of the JVP's electoral effort was at the legislative elections held on 2 April 2004. The party was part of the United People's Freedom Alliance that won 45.6% of the popular vote and 105 out of the 225 seats in Parliament. As the second-largest party of this coalition, it became part of the government with 39 Members of Parliament and three cabinet portfolios.


title: Janatha Vimukthi Peramuna

text: Shortly after the 2004 tsunami, the JVP believed the Sri Lankan government was seeking assistance from the Liberation Tigers of Tamil Eelam (LTTE). After multiple arguments, the JVP and Jathika Hela Urumaya (JHU; Sinhala National Heritage) protested against the peace involvement from Norway. Subsequently, Tamil journalist Dharman Sivaram was assassinated. The Therraputtabaya Brigade, unknown before, issued death threats to multiple other journalists, which included former JVP member Victor Ivan.


title: Janatha Vimukthi Peramuna

text: In 2005, Mahinda Rajapaksa was elected president of Sri Lanka. Some political analysts believed that the majority of support and endorsement to Rajapakse came from the JVP due to Rajapaksha opposing the peace process. A few analysts reject this idea, saying that JVP was too weak to make an influence in mainstream elections. Other independent intellectuals, like Dayan Jayatilleka, Nalin de Silva and Mohan Samaranayake, pointed out that the Rajapaksha agreement with the JVP ensured his victory.


title: Janatha Vimukthi Peramuna

text: The party experienced an internal conflict between the two factions of Wimal Weerawansa and the party leadership in April 2008. The party decided to suspend Weerawansa's on 21 March 2008. Media reports said that Weerawansa had an argument with the leadership based on the disarmament of the Tamil Makkal Viduthalai Pulikal political party, which was attempting to participate in the country's eastern provincial council elections to be held in May 2008 under the ruling United People's Freedom Alliance.


title: Janatha Vimukthi Peramuna

text: A member of the party, Piyasiri Wijenayake, accused the UNP of conspiring against the JVP at a media conference held at Nippon Hotel in Colombo on 8 April 2008. He alleged that Ravi Karunanayake, a UNP member who had attended a meeting with senior JVP leaders at his residence, was the main conspirator. Wijenayake told BBC that his and Achala Suranga Jagoda's vehicles were forcefully removed by the group led by Jayanatha Wijesekara, a Member of Parliament from the Trincomalee district.


title: Janatha Vimukthi Peramuna

text: Weerawansa's group visited the most senior Buddhist monks of Asgiriya and Malwatte chapters on 20 April 2008 to seek blessings for their new political movement. Weerawansa also accused the UNP Kotte leaders of the conspiracy against the JVP. Weerawansa's group then formed a new political party called the Jathika Nidahas Peramuna (JNP). Party activities began on 14 May 2008, the anniversary of the day Wijeweera had formed the JVP in 1965 and of the day the LTTE killed 146 pilgrims during the Anuradhapura massacre at the Sri Maha Bodhi in 1985. The party leaders said that the new political party was an alternative to the two main political parties, UNP and SLFP, but not the JVP. In December 2008, the JNP joined the government, and claimed that the government should be supported at this moment as it was successfully fighting the LTTE in the north of Sri Lanka. JVP politicians blamed the government, saying that it had mishandled many problems, and alleged that their rivals had joined the government for personal gain.


title: Janatha Vimukthi Peramuna

text: JVP formed a coalition with UNP to support Sarath Fonseka, the former army chief, in the 2010 presidential elections, but he was defeated by the incumbent, Mahinda Rajapaksa. After this, the UNP left the coalition and the JVP contested the general elections along with Sarath Fonseka's factions under the banner of Democratic National Alliance. The alliance won 7 seats, of which 4 were won by JVP candidates. The party had 39 seats before the elections.


title: Janatha Vimukthi Peramuna

text: The party had a schism in 2012 when a group of members left the party to make the new Frontline Socialist Party (FLSP). Although the FLSP was not as successful as the JVP, they still participated in elections. FLSP failed to overcome the JVP's popularity, but they remained more active by conducting protests and anti-American propaganda.


title: Janatha Vimukthi Peramuna

text: Premakumar Gunaratnam was an elusive leader and JVP leaders denied his existence. In April 2012, the internal crisis within the party heated up between the hard-core socialist Gunaratnam and the party leader Somawansa Amarasinghe. As a result, the party's media unit was shut down once a majority of the members extended their support to Gunaratnam. The women's wing and a majority of the students and youth wings have extended their support to the Gunaratnam group.


title: Janatha Vimukthi Peramuna

text: Several student union leaders like Duminda Nagamuwa, Udul Premaratne, and Chameera Koswatta sided with the FLSP.


title: Janatha Vimukthi Peramuna

text: JVP neither contested nor directly supported any coalition in the January 2015 presidential election, but it heavily criticised incumbent President Mahinda Rajapaksa, which assisted in his defeat. Later in August the party participated in the parliamentary election and obtained six seats, receiving 543,944 votes.


title: Janatha Vimukthi Peramuna

text: The party went to the elections as National People's Power, and its candidate was Anura Kumara Dissanayake. He received 418,553 votes, which accounted for 3.16% of valid votes in the presidential election. Since then, the party has been called the NPP or JJB (Jathika Jana Balavegaya), but is still referred to as JVP casually.


title: Janatha Vimukthi Peramuna

text: The NPP participated in the 2020 elections, and became fourth from votes. The party gained a total of 445,958 (3.48%) votes, which is the least the party gained since the second election in 1994.


title: Janatha Vimukthi Peramuna

text: Since its creation in 1965, JVP has had major schisms: some branches emerged as militant factions while others participated in elections. Many schisms were due to ideological changes, while others were caused by internal conflicts with other major leaders within the party.


title: Janatha Vimukthi Peramuna

text: Viplavakari Tharuna Peramuna (Ceylon Revolutionary Youth Front) participated with the JVP and the Lanka Sama Samaja Party in a rally on May Day; it is believed to be an offshoot.


title: Janatha Vimukthi Peramuna

text: The Motherland Defense Front was a patriotic front that was formerly a coalition between the JVP and the Maoists. It was succeeded by the Patriotic People's Movement.


title: Janatha Vimukthi Peramuna

text: The Maoist Youth Front was created in 1970 as a Maoist offshoot of the JVP when a certain number of JVP members were expelled from the group. It emerged as a militant organization before collapsing after the first JVP insurrection in 1971. Its leader was Dharmasekara.


title: Black Belt in the American South

text: The Black Belt in the American South refers to the social history, especially concerning slavery and black workers, of the geological region known as the Black Belt. The geology emphasizes the highly fertile black soil. Historically, the black belt economy was based on cotton plantations – along with some tobacco plantation areas along the Virginia-North Carolina border. The valuable land was largely controlled by rich whites, and worked by very poor, primarily black slaves who in many counties constituted a majority of the population. Generally the term is applied to a larger region than that defined by its geology.


title: Black Belt in the American South

text: After 1945, a large fraction of the laborers were replaced by machinery, and they joined the Great Migration to cities of the Midwest and West. Political analysts and historians continue to use the term Black Belt to designate some 200 counties in the South from Virginia to Texas that have a history of majority African-American population and cotton production.


title: Black Belt in the American South

text: By 1894, political commentators used the term "Black Belt" so often that the term was already very well known in the United States. "The Nation" reported in 1894:


title: Black Belt in the American South

text: There are 12 counties in Alabama in each of which the Blacks are twice as numerous as the whites. These 12 counties, stretching across southern Central Alabama from Georgia and Mississippi, constitute the principal portion of the famous Black Belt.


title: Black Belt in the American South

text: By 1900 the term "Black Belt" was commonly used to denote a geopolitical region, much like later coinages such as snow belt, rust belt, sun belt and Bible Belt. Booker T. Washington wrote in his 1901 autobiography


title: Black Belt in the American South

text: I have often been asked to define the term "Black Belt." So far as I can learn, the term was first used to designate a part of the country which was distinguished by the colour of the soil. The part of the country possessing this thick, dark, and naturally rich soil was, of course, the part of the South where the slaves were most profitable, and consequently they were taken there in the largest numbers. Later, and especially since the war, the term seems to be used wholly in a political sense—that is, to designate the counties where the black people outnumber the white.


title: Black Belt in the American South

text: The boundaries of the subregion depend on the exact criteria being used. Census data is used to identify rural Southern counties with a large black population in a particular year. Which percentage and which year depends on the goals of the project—to look at history, or at current patterns, or to project future trends. In 1980, Southern counties with at least 25 percent African-American populations comprised 29 percent of the Southern United States' population, falling to 23 percent in 2005. The white population in the same counties fell from 23 percent to 17 percent. In total numbers, these counties included 6,700,000 blacks in 1980, and 8,400,000 in 2005. They included 10,700,000 whites in 1980 and 11,700,000 in 2005.


title: Black Belt in the American South

text: In 1936 sociologist Arthur Raper described the Black Belt as some 200 plantation counties where blacks represented more than 50% of the population, lying "in a crescent from Virginia to Texas". Black population decreased in some areas after the Second Great Migration, when 4.5 million rural blacks left the region from 1940 to 1970. But the University of Alabama in 2007 classifies "roughly 200 counties" as comprising the Black Belt, with significant black populations. The Mississippi Encyclopedia adds to this definition a long history of cotton production.


title: Black Belt in the American South

text: Political activists and historians continue to use "Black Belt" in considering politics in predominately black rural areas in the South. For example, in 1962, Martin Luther King Jr. wrote of his "People to People" tour through the Black Belt of Virginia: "The idea of 'massive resistance' was spawned not in Georgia or Alabama—–but in the hearts of the Southside Virginia, commonly known as the Black Belt."


title: Black Belt in the American South

text: In 1964 King met with black leaders in to find a target locale to publicize the civil rights movement in Alabama. Large cities were eliminated, so according to historian Charles S. Aiken, "King had only the state's small nonmetropolitan cities from which to select the place to focus the campaign for new voting rights legislation... There was no other choice but the "open spaces" of the Black Belt, and in the Black Belt there was no alternative to Selma."


title: Black Belt in the American South

text: In 2012, political scientist Seth McKee concluded that in the 1964 election, "Once again, the high level of support for Goldwater in the Deep South, and especially their Black Belt counties [where most blacks were still disenfranchised], spoke to the enduring significance of white resistance to black progress."


title: Black Belt in the American South

text: The "Redeemers", a Southern Democratic political coalition that sought to enforce white supremacy, came to power after Reconstruction ended in 1877 and ousted Black and White Republicans from political office across the South. Historian Edward L. Ayers argues the Redeemers were sharply divided, however, and fought for control of the Democratic Party:


title: Black Belt in the American South

text: For the next few years the Democrats seemed in control of the South, but even then deep challenges were building beneath the surface. Behind their show of unity, the Democratic Redeemers suffered deep divisions. Conflicts between upcountry and Black Belt, between town and country, and between former Democrats and former Whigs divided the Redeemers. The Democratic party proved too small to contain the ambitions of all the white men who sought its rewards, too large and unwieldy to move decisively.


title: Black Belt in the American South

text: During the period of disenfranchisement after the Reconstruction Era, mainly the years 1890–1907, white Democrats passed new state constitutions and state laws, and used informal local practices across the South to prevent African-American citizens from registering to vote and voting. States became one-party Democratic bastions in which the general election was a formality. The real battles took place inside the Democratic Party primaries, which were made private by law and not open to blacks. The result was to thwart the objective of the Fifteenth Amendment to the Constitution, which sought to protect the suffrage of freedmen after the American Civil War. Congress did not object, and the Supreme Court generally approved.


title: Black Belt in the American South

text: The mostly black Republican Party of the South rarely won any Black Belt elections after 1900, but it did send delegates to the presidential nominating conventions every four years, thus giving blacks some voice in national politics. President William Howard Taft used black Southern support to defeat ex-President Theodore Roosevelt for the GOP nomination in 1912.


title: Black Belt in the American South

text: After 1900, African Americans, the majority of the population in most of the Black Belt, were rarely allowed to vote, apart from a few ministers, businessmen and schoolteachers. Political power was in the hands of a relatively closed white elite comprising the major landowners, along with local merchants and bankers. They had almost complete control of local government. They generally also had control of the state legislatures, which gerrymandered political districts to strongly favor rural areas and under-represent the cities.


title: Black Belt in the American South

text: By the 1950s, many counties had a local Citizens' Council (the groups were commonly referred to as the "White Citizens' Councils"), which was part an associated network of white supremacist, organizations that directed white resistance to racial integration, especially against integrating the public schools.


title: Black Belt in the American South

text: Federal intervention changed the situation in the 1970s. The Voting Rights Act of 1965 was strictly enforced, to expand the franchise. During the 1960s, the US Supreme Court ruled in several cases covering rural bias in legislatures, saying that under the Equal Protection Clause, states needed to redistrict based on the principle of one man, one vote for equitable representation. As a result, states were prohibited from having bicameral legislatures in which one house was elected by county. In addition, the Court required the states to redistrict every decade to reflect census data, which many had neglected to conduct. The result was to shift political power toward the more populated and industrialized urban areas.


title: Black Belt in the American South

text: Until the mid-20th century, the predominant agricultural system in the Black Belt involved interdependent white land owners, tenant farmers, and sharecroppers; most of the latter groups were African Americans. Tenants typically owned their own tools and draft animals, while the sharecroppers provided no capital and paid fees to the landowner with a share of the crop produced. Very little cash changed hands. The few existing local banks were small; cash was scarce and had to be saved by the landowners for paying taxes.


title: Black Belt in the American South

text: The early 1920s were especially difficult financially in cotton growing regions. The boll weevil, a beetle that feeds on cotton buds and flowers, had migrated into the United States from Mexico in the late 19th century and had infested all U.S. cotton-growing areas by the 1920s, devastating the industry and the people working in the American South. The price of cotton plunged from 37 cents per pound in early 1920 to 10 cents in mid-1921. Land prices plunged 80% and tax rates went up. Tenants could not repay the storekeepers. Land owners were squeezed, for many had used credit to buy land during the World War bubble; and many farms were foreclosed—all this before the Great Depression struck in 1929. Raper's analysis of Black Belt banks shows that deposits plunged by half or more from 1918 to 1932. As a result, most local people became "very shy of banks." New Deal agricultural programs helped the land owners much more than the tenants.


title: Black Belt in the American South

text: Landowners needed a great deal of labor at harvest time to pick cotton. The typical plan after the Civil War and emancipation of the slaves who had provided labor on vast estates in the American South during the antebellum period was for planters to divide the old plantations into many smaller farms that were then assigned to tenant farmers. The tenant farmer and his family worked their plot of land and provided the labor to plant and harvest the crop. Throughout the year, the tenants usually bought food and supplies weekly, on credit, through the local country store (sometimes owned by the planter).


title: Black Belt in the American South

text: At harvest time, the tenants picked and sold their cotton, paid the merchant, and gave the landowner his one-third. There seldom was much cash left over. For sharecroppers, the landlord supplied all their needs during the year and then took the crop. The annual cycle started again, often with a large turnover of sharecroppers. Landowners also worked some of the land directly, using black labor paid in cash. The white landowners held all the political power, and fought vigorously against cash-dispensing government welfare programs that would undermine the cashless system. Economic historians Lee Alston and Joseph Ferrie (1999) describe the system as essentially an informal contract that bound employer and worker through the provision of housing, medical care, and other in-kind services along with cash wages. At its heart, it guaranteed a stable and adequate labor supply to the planter. Though restricted by the directives of the planter, workers in return received some measure of economic stability, including a social safety net, access to financial capital, and some physical protection in an often violent society.


title: Black Belt in the American South

text: There were few alternative jobs in the Black Belt region. When factories opened or retooled to supply the war effort in World War II, and the military draft was introduced, large numbers of African-American farmers left for the army or cash-paying jobs in nearby or distant cities, particularly on the West Coast. This population movement was called the Great Migration. With the beginning of the war, outbound migration increased significantly.


title: Black Belt in the American South

text: A decade after the end of the war, a practical combination of more efficient machinery, such as tractors and cotton harvesters and chemical herbicides finally became available to cotton planters and many landowners began farming the land themselves. Their reduced need for resident farm labor forced many tenant farmers and sharecroppers off the land resulting in an even greater black emigration to the North and West. This is known as the Second Great Migration. Diversified agriculture replaced much of the cotton and tobacco, and gradually industrial-scale agriculture became dominant in large areas of the region.


title: Black Belt in the American South

text: The rural Black Belt, with its largely African-American population, has historically ranked toward the bottom of American regions in terms of quality of life indicators such as poverty rates, median incomes, mortality, unemployment rates, and educational levels. For example, since before the 1950s transportation routes have historically been inadequate in this region. To this day, air transportation facilities are limited.


title: Black Belt in the American South

text: Peter Daniels investigated how the government pushed back on supporting small farms and farmers and pushed more towards a climate of capitalism. Hierarchical systems were a proponent in this climate of capitalism that eroded the agricultural business. In 1913, the USDA planned to distribute payments to the farmers. The farmers felt like they were being pushed to the margin with the empty promises the FHA and Georgia government was giving them. This shows that the FHA, local, and national governments had racist motivation behind reforming the slave system and their efforts were not satisfactory. The USDA was only focusing on large and industrial farms. In turn, this would lead the small farmers (part of the Black Belt) off and out of their lands.


title: Black Belt in the American South

text: Salter, who worked at Tougaloo College, studied how industrialization affected Black farmers. They talked about the fact that the chemical herbicides that the government had used to produce crops more quickly and of lesser quality, started to deteriorate the physical integrity of the lands. Farmers like the Salters could no longer depend on crops like cotton and seasonal crops to support their families, or sell enough to support their families. Even farmers who had more money saved before the government took over their farmlands were still in a parallel position to the lower class farmers. The family farmers and their lands were being replaced by industrial means, and their families stood no chance physically nor did their farms.


title: Black Belt in the American South

text: In the late 19th century, formerly enslaved African Americans in Alabama, now freedmen, were concentrated in the Black Belt, which ran across the central part of the state, mainly in Greene, Hale, Perry, Sumter, Marengo, Dallas, Wilcox, Lowndes, Montgomery, and Bullock counties. Freedmen established churches independent of white supervision, and their own Baptist state and regional associations. Baptist membership grew rapidly in the Black Belt, from a total of 71,000 in 1890 (of whom 86 percent were African-American), to 215,000 in 1916.


title: Black Belt in the American South

text: The planters in the region had been affluent before the Civil War, and typically belonged to the Presbyterian, Episcopal, or Methodist churches. After the war, facing economic losses and disruption to the economy, many of the owners sold out and moved to distant cities. Presbyterian and Episcopal church membership fell. Among the whites, Methodism grew, as did Baptist congregations. In addition, new fundamentalist sects, such as Holiness and Nazarene, began to emerge, but their rapid growth came after 1900.


title: Black Belt in the American South

text: In the white community, Baptist church services were typically held Sundays at 11 AM and 6 PM, with an earlier Sunday school for children. During the week, there were prayer meetings and meetings of the ladies' society and missionary organizations. Smaller rural churches shared a rotating pastor and had a lighter schedule. Occasionally the Baptists would hold rallies promoting membership drives, domestic missions, Christian education, religious literature, prayer in the home, Christian citizenship, and one outside issue, laws to promote temperance. Until the late 19th century, the preachers continued to focus on the need for revivals, and Sabbath observance, on the evils of Catholicism, card playing, dancing and personal sin in general. Every few weeks the churches held trials of their own members for sins such as drunkenness, dancing, or adultery; the usual participant punishment was humiliation or expulsion from the congregation. The theology was traditional, with no trace of modernist readings of the Bible. Unlike the Methodists and Presbyterians, few Baptist pastors were educated. Instead, the local congregation selected and ordained ministers on the basis of their religiosity and ability to articulate God's word. By 1900, the range of sermons and editorials had been enlarged to cover new social themes. Baptists still opposed Catholicism, but now they talked of cooperation with other Protestant churches. There was less emphasis on card playing and dancing, and more interest in issues of underpaid laborers, coal miners, and workers in sweatshops. This indicated a newfound interest in the Social Gospel, although not nearly at the level of Northern Protestant churches. Racial tensions and discrimination was not mentioned, nor the rate of lynchings, which peaked in the late 19th and early 20th centuries.


title: Black Belt in the American South

text: Many, probably most, slaves had become Christians during the antebellum period. Their religious preferences focused on evangelical religion with strong participation by the congregations, and led by a strong minister who typically was also a political leader. By 1867, freedmen, with help from the Freedmen's Bureau, began organizing their own separate all-black churches. Northern Methodist missionaries helped organize such churches as were affiliated with the national Methodist Church. More popular were the African Methodist Episcopal Church and African Methodist Episcopal Zion Church, the first independent black denominations, whose missionaries planted thousands of new churches.


title: Black Belt in the American South

text: White southern Methodists had a separate body, and they sponsored the Colored Methodist Episcopal Church. Small numbers of African Americans belonged to the Episcopalian and Presbyterian churches. All the Methodists had a hierarchical organization led by bishops.


title: Black Belt in the American South

text: Many blacks organized independent Baptist churches, quick to establish congregations without white supervision. At their first state convention in 1868, the 60 Baptists attending represented 32 churches. By 1881 the church had 50 district associations, 600 churches, 700 preachers, and about 90,000 members in the state, and operated a small seminary in Selma; most of the ministers were strong orators but barely literate. Although the revivalist camp meeting movement was fading away in the white churches, it grew more popular in the black community. In addition to all-day Sunday services, many Black Baptists became active in Sunday schools and missionary societies.


title: Black Belt in the American South

text: Although racial tensions often grew violent during the Reconstruction era (1863–1877), in the Alabama black belt some compromise was reached through a sharecropping system in which local black farmers were under the protection of rich white landowners. According to a review of a 2015 history of Reconstruction in Alabama:


title: Black Belt in the American South

text: The strength of African-American activism and, to a lesser extent, the moderation of elite planters meant that in the black belt Reconstruction essentially worked. Sharecropping developed as a compromise that allowed white planters to make money while black workers preferred its relatively greater autonomy in comparison to slavery. As a result of the labor compromise that developed, the black belt saw less terroristic white supremacist violence than did northern Alabama. Fitzgerald’s work thus adds specific teeth to the arguments of Steven Hahn—and before him, W. E. B. Du Bois —about the political acumen and solidarity of rural African Americans. White planters obviously were at the top of economic and political ladders, but black tenant farmers were real agents of power.


title: Black Belt in the American South

text: William J. Northen (1835–1913), was the Governor of Georgia from 1890 to 1894. A leading Baptist minister, Northen was president of the Georgia Baptist Convention from 1892 to 1910, and president of the Southern Baptist Convention from 1899 to 1901. His political rhetoric was based on his religious outlook. He often addressed racial issues at a time when the rate of lynching was growing rapidly. Northen believed that advances in medicine and health would ultimately help African Americans achieve salvation. He promoted the ideology of the modernizing New South, but did not abandon the policy of white supremacy.


title: Black Belt in the American South

text: The study of women's history and gender roles in the Black Belt has been a recent development. Chrissy Lutz and Dawn Herd-Clark in 2019 explored the situation of black housewives in Georgia's black belt in the 1920s and 1930s. They worked with outside agencies to improve their own work efficiency and economic opportunities. Fort Valley State College, a historically black college, collaborated with the segregated unit of the Cooperative Extension Service, an educational arm of the United States Department of Agriculture. They trained and supplied black organizers, set up and funded local clubs, and gave farm and home demonstrations. They focused on the integral domestic work of cooking, hygiene, sewing, garden cultivation and food processing, and poultry raising. Not only did they teach new skills, they helped isolated rural women to meet each other and form supportive friendships. The systematic end of rural isolation meant that black rural women could affirm that "no one was on their own."


title: Black Belt in the American South

text: Economic historians of the South generally emphasize the continuity of the system of white supremacy and cotton plantations in the Black Belt from the late colonial era into the mid-20th century, when it collapsed. Harold D. Woodman summarizes the external forces that caused this disintegration from the 1920s to the 1970s:


title: Black Belt in the American South

text: When significant change finally occurred, its impetus came from outside the South. Depression-bred New Deal reforms, war-induced demand for labor in the North, perfection of cotton-picking machinery, and civil rights legislation and court decisions finally...destroyed the plantation system, undermined landlord or merchant hegemony, diversified agriculture and transformed it from a labor- to a capital-intensive industry, and ended the legal and extralegal support for racism. The discontinuity that war, invasion, military occupation, the confiscation of slave property, and state and national legislation failed to bring in the mid nineteenth century finally arrived in the second third of the twentieth century.


title: Black Belt in the American South

text: The most prominent analyst of the Black Belt was sociologist W. E. B. DuBois, who engaged in statistically based studies of family life, economic cooperation, and social conditions as editor of "The Atlantic University Publications" in the early 20th century. His 1903 book "The Souls of Black Folk" contains extensive analysis and reflection. Du Bois calls Albany, Georgia, in Dougherty County, the "heart of the Black Belt". He says: "Here are the remnants of the vast plantations."


title: Black Belt in the American South

text: How curious a land is this,- how full of untold story, of tragedy and laughter, and the rich legacy of human life; shadowed with a tragic past, and big with future promise!


title: Black Belt in the American South

text: Yet, he notes, it is not far from "where Sam Hose was crucified" [in a lynching], "to-day the centre of the Negro problem,-the centre of those nine million men who are America's dark heritage from slavery and the slave-trade." He continues: "Careless ignorance and laziness here, fierce hate and vindictiveness there,—these are the extremes of the Negro problem which we met that day, and we scarce knew which we preferred."


title: Black Belt in the American South

text: The civil rights movement and related changes in the production of history of African Americans raised new interest in elements of their history in the South, including during slavery times. Since the late 20th century, there has been a new emphasis on the restoration, preservation and historical analysis of African-American dwelling units in the Black Belt, especially those surviving from slavery days. Ashley A. Dumas, et al. explain the rationale:


title: Black Belt in the American South

text: Slave houses are artifacts. Their attributes can be recorded, analyzed, and broad patterns about their historical context, their builders, and inhabitants revealed. The methods of construction, for instance, often indicate climate, economy, and available technology. Ethnographic and archaeological studies demonstrate that houses, yards, and landscapes reflect cultural values and social relationships and changes to these. The organization of labor may be inferred from the placement of houses in relation to one another and to non-domestic buildings.In certain areas of what was once the Black Belt, citizens began to honor the events that took place there.


title: Black Belt in the American South

text: In Selma, Alabama there is the Central Loop located in the heart of the city, which is rich in the Black Belt history. The Civil War Battle of Selma and the Voting Rights era were the heart of Selma's history. One attraction of Selma is the Edmund Pettus Bridge. This bridge gained widespread popularity when activists marched pridefully from Selma to Montgomery in opposition to discrimination against African Americans. Law enforcement came in and forcefully handled the protesters, with tear gas and physically assaulting the protesters. This showed the injustice and discrimination that the African Americans faced when they were just trying to fight for their rights. These events are now on TV for everyone to witness, and are termed “Bloody Sunday”.


title: Black Belt in the American South

text: Led by Martin Luther King Jr. in the 1960s, the Voting Rights emerged. The people involved in the Voting Rights arranged the First Baptist Church. This church was used as a vehicle to give food, clothes, and supplies to fellow Voting Rights activists. The building where King spoke out against the discrimination that the African Americans were bearing, the church was destroyed in 1894 by law enforcement. In 1982, it was rebuilt as a historic site. It is the initial point where people go to start the Martin Luther King Jr. Street Historic Tour.


title: Black Belt in the American South

text: To honor one of the martyrs of the civil rights area, the Interpretive Center was constructed as part of the historic tour. The Interpretive Center replicates how the Kings lived, with replicas of furniture, paintings, and household items which the Kings had in their house during the time. Additionally, there is a film shown during the tour that is called, “Here I stand”. It is a reenactment of how the King's house was bombed during the boycott.


title: Black Belt in the American South

text: Industrialization in small farming production was a mark of the history of the Black Belt. In Auburn, there were 1116 acres of land that were contaminated with fescue toxicity and were fed to cattle. This was just one of the 5 stations that were poisoned with toxic pesticides and fed cattle toxins to produce a higher quantity of food. Now, the plots have been transformed into the Black Belt Research and Experimentation Center. Auburn University used the lands that were filled with toxins to study how to manage fungus-infected pesticides and helped contribute to her beef production in the US. This area is used by students at Auburn for research but also is open for visitors to see the progression of farming in the Black Belt.


title: Black Belt in the American South

text: The Tuskegee Institution National Historic Site: Carver Museum pays homage to Booker T. Washington and George Washington Carver. Each of these men worked to reform the agriculture system that was negatively transformed by discrimination and racism. When the African Americans were pushed out of their righteous land, the Tuskegee Institute was founded by Washington in 1881. This institution helped to educate African Americans about how to farm, their legal land rights, and the financial managerial aspect of farming.


title: Black Belt in the American South

text: The Carver Museum honors the professor and activist who worked tirelessly to transform Southern agriculture. The museum holds original photographs, physical objects that were used during the time, and live reenactments.


title: Black Belt in the American South

text: In 1939, the US government let African Americans train to be Airmen In the United States Military. Civil Pilot Training was enacted and took place at the Tuskegee Institute. The men learned how to fly and navigate a plane, combat weather, and climate issues, and engineer the plans. When the US had entered World War II, the airmen began to report for duty. Now termed the “Tuskegee Experiment”, 992 pilots and 10,000 people of staff had more to fight against than the white airmen who were trained to fight the enemy overseas. The Airmen who had parallel trading to the white airmen had to suffer through the racist climate in the South and the segregation in the US surrounding them as being the first black airmen.


title: Black Belt in the American South

text: To honor this in 1988, President Clinton passed a law that instituted the Tuskegee Airmen National Historic Site at Norton Field.


title: Continental crust

text: Continental crust is the layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents and the areas of shallow seabed close to their shores, known as continental shelves. This layer is sometimes called "sial" because its bulk composition is richer in aluminium silicates (Al-Si) and has a lower density compared to the oceanic crust, called "sima" which is richer in magnesium silicate (Mg-Si) minerals. Changes in seismic wave velocities have shown that at a certain depth (the Conrad discontinuity), there is a reasonably sharp contrast between the more felsic upper continental crust and the lower continental crust, which is more mafic in character.


title: Continental crust

text: The continental crust consists of various layers, with a bulk composition that is intermediate (SiO wt% = 60.6). The average density of continental crust is about , less dense than the ultramafic material that makes up the mantle, which has a density of around . Continental crust is also less dense than oceanic crust, whose density is about . At in thickness, continental crust is considerably thicker than oceanic crust, which has an average thickness of around . Approx. 41% of Earth's surface area and about 70% of the volume of Earth's crust is continental crust.


title: Continental crust

text: Most continental crust is dry land above sea level. However, 94% of the Zealandia continental crust region is submerged beneath the Pacific Ocean, with New Zealand constituting 93% of the above-water portion.


title: Continental crust

text: Because the surface of continental crust mainly lies above sea level, its existence allowed land life to evolve from marine life. Its existence also provides broad expanses of shallow water known as epeiric seas and continental shelves where complex metazoan life could become established during early Paleozoic time, in what is now called the Cambrian explosion.


title: Continental crust

text: All continental crust is ultimately derived from mantle-derived melts (mainly basalt) through fractional differentiation of basaltic melt and the assimilation (remelting) of pre-existing continental crust. The relative contributions of these two processes in creating continental crust are debated, but fractional differentiation is thought to play the dominant role. These processes occur primarily at magmatic arcs associated with subduction.


title: Continental crust

text: There is little evidence of continental crust prior to 3.5 Ga. About 20% of the continental crust's current volume was formed by 3.0 Ga. There was relatively rapid development on shield areas consisting of continental crust between 3.0 and 2.5 Ga. During this time interval, about 60% of the continental crust's current volume was formed. The remaining 20% has formed during the last 2.5 Ga.


title: Continental crust

text: Proponents of a steady-state hypothesis argue that the total volume of continental crust has remained more or less the same after early rapid planetary differentiation of Earth and that presently found age distribution is just the result of the processes leading to the formation of cratons (the parts of the crust clustered in cratons being less likely to be reworked by plate tectonics). However, this is not generally accepted.


title: Continental crust

text: In contrast to the persistence of continental crust, the size, shape, and number of continents are constantly changing through geologic time. Different tracts rift apart, collide and recoalesce as part of a grand supercontinent cycle.


title: Continental crust

text: There are currently about of continental crust, but this quantity varies because of the nature of the forces involved. The relative permanence of continental crust contrasts with the short life of oceanic crust. Because continental crust is less dense than oceanic crust, when active margins of the two meet in subduction zones, the oceanic crust is typically subducted back into the mantle. Continental crust is rarely subducted (this may occur where continental crustal blocks collide and overthicken, causing deep melting under mountain belts such as the Himalayas or the Alps). For this reason the oldest rocks on Earth are within the cratons or cores of the continents, rather than in repeatedly recycled oceanic crust; the oldest intact crustal fragment is the Acasta Gneiss at 4.01 Ga, whereas the oldest large-scale oceanic crust (located on the Pacific Plate offshore of the Kamchatka Peninsula) is from the Jurassic (≈180 Ma), although there might be small older remnants in the Mediterranean Sea at about 340 Ma. Continental crust and the rock layers that lie on and within it are thus the best archive of Earth's history.


title: Continental crust

text: The height of mountain ranges is usually related to the thickness of crust. This results from the isostasy associated with orogeny (mountain formation). The crust is thickened by the compressive forces related to subduction or continental collision. The buoyancy of the crust forces it upwards, the forces of the collisional stress balanced by gravity and erosion. This forms a keel or mountain root beneath the mountain range, which is where the thickest crust is found. The thinnest continental crust is found in rift zones, where the crust is thinned by detachment faulting and eventually severed, replaced by oceanic crust. The edges of continental fragments formed this way (both sides of the Atlantic Ocean, for example) are termed passive margins.


title: Continental crust

text: The high temperatures and pressures at depth, often combined with a long history of complex distortion, cause much of the lower continental crust to be metamorphic – the main exception to this being recent igneous intrusions. Igneous rock may also be "underplated" to the underside of the crust, i.e. adding to the crust by forming a layer immediately beneath it.


title: Continental crust

text: Continental crust is produced and (far less often) destroyed mostly by plate tectonic processes, especially at convergent plate boundaries. Additionally, continental crustal material is transferred to oceanic crust by sedimentation. New material can be added to the continents by the partial melting of oceanic crust at subduction zones, causing the lighter material to rise as magma, forming volcanoes. Also, material can be accreted horizontally when volcanic island arcs, seamounts or similar structures collide with the side of the continent as a result of plate tectonic movements. Continental crust is also lost through erosion and sediment subduction, tectonic erosion of forearcs, delamination, and deep subduction of continental crust in collision zones. Many theories of crustal growth are controversial, including rates of crustal growth and recycling, whether the lower crust is recycled differently from the upper crust, and over how much of Earth history plate tectonics has operated and so could be the dominant mode of continental crust formation and destruction.


title: Continental crust

text: It is a matter of debate whether the amount of continental crust has been increasing, decreasing, or remaining constant over geological time. One model indicates that at prior to 3.7 Ga ago continental crust constituted less than 10% of the present amount. By 3.0 Ga ago the amount was about 25%, and following a period of rapid crustal evolution it was about 60% of the current amount by 2.6 Ga ago. The growth of continental crust appears to have occurred in "spurts" of increased activity corresponding to five episodes of increased production through geologic time.


title: Long take

text: When filming "Rope" (1948), Alfred Hitchcock intended for the film to have the effect of one long continuous take, but the camera magazines available could hold not more than 1000 feet of 35 mm film. As a result, each take used up to a whole roll of film and lasts up to 10 minutes. Many takes end with a dolly shot to a featureless surface (such as the back of a character's jacket), with the following take beginning at the same point by zooming out. The entire film consists of only 11 shots.


title: Long take

text: Andy Warhol and collaborating avant-garde filmmaker Jonas Mekas shot a 485-minute-long experimental film, "Empire" (1965), on 10 rolls of film using an Auricon camera via 16 mm film which allowed longer takes than its 35 mm counterpart. "The camera took a 1,200ft roll of film that would shoot for roughly 33 minutes."


title: Long take

text: A handful of theatrically released feature films, such as "Timecode" (2000), "Russian Ark" (2002), "PVC-1" (2007), "Victoria" (2015) and "Boiling Point" (2021) are filmed in one single take. Others are composed entirely from a series of long takes, while many more may be well known for one or two specific long takes within otherwise more conventionally edited films. In 2012, the art collective The Hut Project produced "The Look of Performance", a digital film shot in a single 360° take lasting 3 hours, 33 minutes and 8 seconds. The film was shot at 50 frames per second, meaning the final exhibited work lasts 7 hours, 6 minutes and 17 seconds.