title: Sea Fever

text: A. A. Dowd of "The A.V. Club" gave the film a "B−", writing that ""Sea Fever" tackles [its premise] with almost too much restraint [...] All the same, there's no denying that the movie eventually reaches a confrontation of disturbing relevance." Devika Girish of "The New York Times" wrote that the film "seems unsure about its own shape, switching indecisively between creature feature, epidemic thriller and environmental drama without articulating any meaty ideas." Tomris Laffly of RogerEbert.com gave the film two out of four stars, concluding: "You'll leave Hardiman's deck wondering why you aren't more rattled, or even seasick, while hoping for another genre flick from the clearly skilled director soon. Perhaps one that anchors into a deeper story this time."


title: David Croft (broadcaster)

text: David Michael Croft (born 19 June 1970) is a British television broadcaster for Sky Sports. He is the lead commentator for Sky's Formula One coverage, a role he has held since 2012. He was born and raised in Stevenage, England.


title: David Croft (broadcaster)

text: Croft began his broadcasting career in hospital radio at Radio Fairfield. He spent three years working at BBC Three Counties Radio, first as a sports reporter then as sports editor. He moved to BBC Radio 5 Live in December 1998. During his time at the station he covered the 2002 FIFA World Cup, 2004 Athens Summer Olympics and presented Saturday Sport on 5 during both the summer of 2004 and 2005.


title: David Croft (broadcaster)

text: Croft was the BBC Radio 5 Live Formula One commentator and presenter, succeeding Maurice Hamilton at the start of the 2006 Formula 1 season. He worked alongside former Super Aguri, Honda and Minardi F1 driver Anthony Davidson and pitlane reporters Ted Kravitz and Natalie Pinkham, covering each Grand Prix and qualifying as well as the three practice sessions which could be heard via the BBC Red Button service, BBC Sport Online and BBC Radio 5 Live Sports Extra. It was announced on 7 December 2011 that Croft would be lead commentator for Sky Sports' coverage of F1 for the 2012 season, and would be joined by Anthony Davidson, Ted Kravitz, Natalie Pinkham and Martin Brundle.


title: David Croft (broadcaster)

text: Croft celebrated his 250th Grand Prix as a Formula One commentator at the 2019 Azerbaijan Grand Prix.


title: David Croft (broadcaster)

text: Croft has also commentated on the BDO World Darts Championship and Winmau World Masters for BBC Television from 2004 to 2012 after first covering the World Championship for BBC Radio 5 Live in 2002. From 2013 onwards, Croft has been working as a presenter and occasional commentator for Sky Sports' coverage of Professional Darts Corporation events.


title: David Croft (broadcaster)

text: He is the voice of the paddock reporter in the Codemasters "F1 2010" game and in the sequel "F1 2011". In "F1 2012", "F1 2013", and "F1 2014", he guides the player through the games' respective menus, and in "F1 2015", "F1 2016", "F1 2017", "F1 2018", "F1 2019", "F1 2020", "F1 2021" and "F1 22" he is a commentator during in-game sessions alongside Anthony Davidson.


title: David Croft (broadcaster)

text: Croft also voiced the character of Lofty Crofty in the European release of "Planes". The character was the European equivalent of Colin Cowling.


title: David Croft (broadcaster)

text: Croft has previously presented a midweek sports show and a Monday night football phone-in show on BBC London 94.9FM, where he has also stood in for Paul Ross and co-presented the Breakfast show first with JoAnne Good and then Gaby Roslin.


title: David Croft (broadcaster)

text: Croft is a fan of rock music and is regular contributor to Primordial Radio with his Crofty's Tracks appearing on the afternoon show with Dewsbury.


title: Kente cloth

text: Kente ( or "nwetoma"; ; Dagbani: Chinchini) refers to a Ghanaian textile, made of handwoven cloth, strips of silk and cotton. Historically the fabric was worn in a toga-like fashion by royalty among ethnic groups such as the Ashanti and Ewe. It is also worn by queens, princesses and women of Dagbon. In modern day Ghana, the wearing of kente cloth has become widespread to commemorate special occasions, with highly sought-after kente brands led by master weavers.


title: Kente cloth

text: Due to the popularity of kente cloth patterns, kente print, which is a mass-produced version, is popular throughout the West. Globally, the print is used in the design of academic stoles in graduation ceremonies.


title: Kente cloth

text: Kente comes from the word "kenten", which means "basket" in the Asante dialect of the Akan language, referencing its basket-like pattern. In Ghana, the Akan ethnic group also refers to kente as "nwentoma", meaning "woven cloth". Ashanti folklore includes a story where weavers invented kente by seeking to replicate the patterns of Anansi the spider.


title: Kente cloth

text: Kente may have developed from a variety of weaving traditions which existed in Ghana since before the 11th century, with excavations in the region showing instruments such as spindles, whorls, and loom weights. By the 18th century, during the rise of the Ashanti Empire, kente became popularized among Akan royalty, and by the early 19th century master weavers and kente houses could be seen throughout the Ashanti capital of Kumasi.


title: Kente cloth

text: Kente production can be classified by three versions: authentic kente cloth made by traditional weavers, kente print produced by brands such as Vlisco and Akosombo Textile Ltd, and mass-produced kente pattern typically produced in China for Westerners. Authentic kente cloth is the most expensive, while kente print varies in price depending on production style.


title: Kente cloth

text: For authentic kente, the towns of Bonwire, Sakora Wonoo, Ntonso, Safo and Adanwomase are noted for kente weaving, and are located in the Ashanti region.


title: Kente cloth

text: Weaving is done on a wooden loom in which multiple threads of dyed fabric are pressed together. Weavers are typically apprenticed under a master weaver or company for a number of years before producing their own patterns. Rolls of cloth are then imprinted with a brand to signify authenticity.


title: Kente cloth

text: Gender has an influence on cloth production. Weaving kente is traditionally considered a male practice.


title: Kente cloth

text: There exist hundreds of different kinds of kente patterns. Kente patterns vary in complexity, with each pattern having a name or message by the weaver. Ghanaians choose kente cloths as much for their names as their colors and patterns. Although the cloths are identified primarily by the patterns found in the lengthwise (warp) threads, there is often little correlation between appearance and name. Names are derived from several sources, including proverbs, historical events, important chiefs, queen mothers, and plants. The cloth symbolizes high value.


title: Kente cloth

text: "Ahwepan" refers to a simple design of warp stripes, created using plain weave and a single pair of heddles. The designs and motifs in kente cloth are traditionally abstract, but some weavers also include words, numbers and symbols in their work. Example messages include "adweneasa", which translates as "i've exhausted my skills", is a highly decorated type of kente with weft-based patterns woven into every available block of plain weave. Because of the intricate patterns, "adweneasa" cloth requires three heddles to weave.


title: Kente cloth

text: In June 2020, Democratic Party leaders in the United States caused controversy by wearing stoles made of kente cloth to show support against systemic racism. While it was said to be an act of unity with African-Americans, many, including Jade Bentil, a Ghanaian-Nigerian researcher, voiced objection tweeting "My ancestors did not invent Kente cloth for them to be worn by publicity (obsessed) politicians as 'activism' in 2020". On the other hand Congressional Black Caucus chair Karen Bass said, at a news conference for the introduction of the Justice in Policing Act of 2020, that the non-black lawmakers were showing solidarity, and April Reign, who is credited with initiating the #OscarsSoWhite hashtag, while not a fan of the symbolism, suggested that the legislation's fate is more relevant than the event in the Capitol's Emancipation Hall.


title: Kente cloth

text: There is also a controversy with Louis Vuitton's usage of a printed and monogrammed version of kente in their autumn-winter 2021 collection by American creative director Virgil Abloh, whose grandmother was Ghanaian. Additionally, questions of ownership of the woven craft, its image, and location of ateliers of production of kente. To this question of cultural appropriation, Abloh's response to the press in 2020 was: "Provenance is reality; ownership is a myth. In the same way, we cannot control our inspirations, we cannot trade-mark natural or cultural heritage as contemporary artistic territory." This coincided with the first appearance of this design of kente cloth printed on a dress worn by American poet Amanda Gorman for the cover of "Vogue"'s May 2021 issue.


title: Jack Whitehall: Travels with My Father

text: Jack Whitehall: Travels with My Father is a travel documentary/road trip comedy television series that debuted on Netflix. The show is presented by comedian Jack Whitehall and his father, Michael Whitehall. The show covers the pair's travels to various places around the world, encountering silly and awkward situations.


title: Jack Whitehall: Travels with My Father

text: The first series consist of six episodes and was released on Netflix on 22 September 2017, and covers the pair's travel to South East Asia on a popular "gap year route", and involves them travelling through Thailand, Vietnam, and Cambodia. The series was renewed for a second series which was filmed in Eastern Europe. The second season premiered on 28 September 2018, and consisted of five episodes.


title: Jack Whitehall: Travels with My Father

text: The third season was filmed in the American west and premiered on 6 September 2019, and only consisted of two episodes. The fourth season was filmed in Australia and premiered on 22 September 2020, and consisted of another two episodes. A fifth season, filmed in the U.K. and consisting of three episodes, was released on 14 September 2021.


title: Jack Whitehall: Travels with My Father

text: Series 1 sees Jack and his father, Michael, embark on the trip of a lifetime across South East Asia. Along the way the pair visits Thailand, Cambodia and Vietnam.


title: Jack Whitehall: Travels with My Father

text: In the second series, Jack and his father, Michael, embark on a road trip across Europe. It is to be a trip of high culture and timeless art, a true rite of passage in the vein of the 18th-century Grand Tours, however, Jack has other plans. Along their way they visit Germany, Hungary, Romania, Moldova, Ukraine and Turkey.


title: Jack Whitehall: Travels with My Father

text: In the third series, Jack shows his father around the American west in the hope that he will move there with him. However, in usual fashion, Michael tries to take the whole trip over.


title: Jack Whitehall: Travels with My Father

text: In the fifth and final series, Jack shows his father around the United Kingdom; later they reminisce about their favorite moments on the series.


title: M6 motorway

text: The M6 motorway is the longest motorway in the United Kingdom. It is located entirely within England, running for just over from the Midlands to the border with Scotland. It begins at Junction 19 of the M1 and the western end of the A14 at the Catthorpe Interchange, near Rugby before heading north-west. It passes Coventry, Birmingham, Wolverhampton, Stoke-on-Trent, Preston, Lancaster and Carlisle before terminating at Junction 45 near Gretna. Here, just short of the Scottish border it becomes the A74(M) which continues to Glasgow as the M74. Its busiest sections are between junctions 4 and 10a in the West Midlands, and junctions 16 to 19 in Cheshire; these sections have now been converted to smart motorways.


title: M6 motorway

text: It incorporated the Preston By-pass, the first length of motorway opened in the UK and forms part of a motorway "Backbone of Britain", running north−south between London and Glasgow via the industrial North of England. It is also part of the east−west route between the Midlands and the east-coast ports. The section from the M1 to the M6 Toll split near Birmingham forms part of the unsigned E-road E 24 and the section from the M6 Toll and the M42 forms part of E 05.


title: M6 motorway

text: The M6 motorway runs from junction 19 of the M1 and the A14 in Catthorpe near Rugby in central England. It passes Coventry, Birmingham, Stafford, Wolverhampton and Stoke-on-Trent. The motorway has major junctions with the M56 and M62 near Warrington, giving access to Chester, Manchester and Liverpool. It also meets the M65 at Junction 29, south of Preston, which connects Blackburn and Burnley, and the M55 at junction 32, north of Preston which links it to Blackpool. The M6 then heads north past Wigan, Preston and Lancaster. After the latter two cities it passes through Cumbria with some parts very close to the edge of the Lake District with a short stretch within the national park boundaries and then passes Carlisle on its way to Gretna, before the motorway becomes the A74(M) a few hundred metres short of the Scottish border.


title: M6 motorway

text: The first section of the motorway and the first motorway in the country was the Preston By-pass. It was built by Tarmac Construction and opened by the Prime Minister Harold Macmillan on 5 December 1958. In January 1959 the Preston by-pass was closed because of rapid surface deterioration over a stretch of "due to water freezing and then thawing". Motorists were diverted to the old road while the UK road research laboratory at Harmondsworth pondered the importance of surface water drainage.


title: M6 motorway

text: The second phase of construction was completed in 1960, forming the Lancaster by-pass. Some south, the Stafford by-pass was completed in 1962. By 1965, the remaining sections of motorway Stafford–Preston and Preston–Lancaster had been completed. 1966 saw junction 11 to 13 completed.1968 saw the completion of the Walsall to Stafford link as well as the Penrith by-pass some north in Cumberland. In 1970, the Lancaster–Penrith link was completed, along with a short section of motorway by-passing the south of Walsall. The most northerly section of the motorway also opened in 1970, running to the designated terminus north of Carlisle. By 1971 the full route was completed between the junction with the M1 motorway at Rugby and the A38 road several miles north-east of Birmingham city centre, including Bromford Viaduct between Castle Bromwich (J5) and Gravelly Hill (J6), which at is the longest viaduct in Great Britain.


title: M6 motorway

text: Junction 6 in Birmingham is widely known as Spaghetti Junction because of its complexity and round and curvy-like design. On the elevated ground between Shap and Tebay, the north and south-bound carriages split apart. At this point a local road (to Scout Green) runs between the two carriageways without a link to the motorway.


title: M6 motorway

text: The section of the M6 that runs over Shap Fell in Cumbria is above sea level, one of the highest points on any motorway in the UK (Junction 22 of the M62 on Saddleworth Moor is higher). The motorway engineers here chose to follow the route of the Lancaster and Carlisle Railway engineered by Joseph Locke (now part of the West Coast Main Line) where the motorway runs in a split-level cutting above the railway in the descent from Shap Fell through the Lune Gorge into southern Cumbria.


title: M6 motorway

text: The northbound entry slip road at Lancaster (Junction 34) was unusually short, presenting problems for traffic joining the motorway. The M6 crosses the River Lune at this point and unless the bridge had been made wider, there was no space to build a longer slip road. This junction was upgraded from an earlier emergency-vehicles-only access point, which explains the substandard design. The construction of the Heysham to M6 Link Road (The Bay Gateway) has completely re-modelled this junction with a wide additional bridge over the River Lune and other works repositioning slip roads with new acceleration lanes to modern standards.


title: M6 motorway

text: The route was originally intended to replace the old A6, which it does along the northern section starting with the Preston Bypass. However, a much closer approximation to the overall actual route of the M6 (heading north from its southern terminus) is provided by following the A45, A34, A50, A49, then the A6. South of Preston, the A6 route is instead supplemented by the M61 as far as Manchester, with the M60 acting as a bypass around the city. South of Manchester, there is no true motorway replacement for the old road. The M1 acts as a bypass for long-distance traffic in the south, from the Kegworth junction near Nottingham, to Luton and St. Albans near London; but, it is not an alternative for local traffic as the routes diverge by more than while passing through Northamptonshire. Across the Pennines, the old road remains the main local through-route, and long-distance fast traffic between Derby and Manchester must instead take either the A50 and M6, or M1 and M62.


title: M6 motorway

text: Once all sections of the motorway were constructed, and it was finally all linked together, the result was an uninterrupted motorway length of .


title: M6 motorway

text: In July 1972 the UK Minister for Transport Industries announced that of UK motorway particularly prone to fog would benefit from lighting in a project which "should be" completed by 1973. Sections to be illuminated included the M6 between junctions 10 and 11, and between junctions 20 and 27.


title: M6 motorway

text: In March 2006, after 15 years of debate, the government authorised the construction of a extension of the M6 from its then northern terminus near Carlisle to the Anglo-Scottish border at Gretna (the so-called "Cumberland Gap"), where it links into the existing A74(M). The road opened on 5 December 2008, the 50th anniversary of the M6 Preston By-pass. The project, which was a mixture of new road and upgrade of the existing A74, crosses the West Coast Main Line and had an estimated costs of £174 million. It completed an uninterrupted motorway from just south of Dunblane (via the M9, the recently opened M80 section near Cumbernauld and the M73) in the north to Exeter (via the M5) and to London (via both the M42/M40 and the M1) in the south.


title: M6 motorway

text: The M6 Toll, Britain's first toll motorway, which bypasses the West Midlands conurbation to the east and north of Birmingham and Walsall and was built to alleviate congestion through the West Midlands, and opened in December 2003. Before the opening of the toll motorway, this section of the M6 carried 180,000 vehicles per day at its busiest point near Wolverhampton (between the junctions with the M54 and M5 motorways), compared with a design capacity of only 72,000 vehicles. Usage, at about 50,000 vehicles, was lower than expected and traffic levels on the M6 were only slightly reduced as a result. The high toll prices, which were set by the operating company and over which the UK Government has no influence until 2054, were blamed for the low usage. Much traffic continues to use the M6 or the continued on the M1 and took the A50 or A52. the road between Junctions 3A and 11A now carries 120,000 motor vehicles every day.


title: M6 motorway

text: A proposed extension to the M6 Toll known as the 'M6 Expressway', which would have continued from the M6 Toll as far as Knutsford, at which point much of the existing M6 traffic leaves the M6 for Manchester, was abandoned in 2006 due to excessive costs, anticipated construction problems and disappointing levels of use of the M6 Toll.


title: M6 motorway

text: In October 2007, following a successful trial on the M42 in the West Midlands, the government announced that two stretches of the M6 would be upgraded to allow the hard shoulder to be used as a normal running lane during busy conditions under a scheme called active traffic management. The two stretches, between junctions 4 and 5 and between junctions 10a and 8, are two of the busiest sections on the entire motorway. It was then proposed that the system could be extended onto other stretches of the M6 while the government undertook a feasibility study to determine other likely locations for this technology to be used. The stretch between junctions 4 and 5 was completed during December 2009 while the stretch between junctions 10a and 8 was completed during March 2011. This was then followed by a stretch between junctions 5 and 8 which started construction in April 2012 and was completed in October 2014.


title: M6 motorway

text: In April 2021, the M6 gained the first motorway service station to be built for thirteen years. Located off Junction 1 at Rugby and opened on 30 April 2021, the facility, run by Moto Hospitality, includes the largest electric vehicle charging facility in the UK, run by Ecotricity and Gridserve.


title: M6 motorway

text: After plans of the government to improve reliability and capacity between Junctions 11 by Cannock and Junction 19 near Knutsford, it favoured a new motorway in 2004, 'The Expressway' following a roughly parallel course to the existing M6. In July 2006, the government announced its decision to abandon the Expressway proposal, and favoured widening accompanied by demand-management measures, and launched a study to consider options for providing additional capacity. After the stretch between junction 10a and 13 was upgraded to a managed motorway in February 2016, it was then proposed to introduce a managed motorway between junction 13 and 19, later divided into two separate stretches, between junctions 16 and 19 and junctions 13 and 15. The stretch between junctions 16 and 19 started construction in December 2015 and was completed in March 2019 while construction on the stretch between junctions 13 and 15 commenced in March 2018.


title: M6 motorway

text: Work started in 2020 to reconstruct the bridges above the M6 at junction 10 due to frequent congestion at peak times.


title: M6 motorway

text: Data from driver location signs are used to provide distance and carriageway identifier information. Where a junction spans several hundred metres (yards) and the start and end distances are known, both distances are shown.


title: M6 motorway

text: Each motorway in England requires that a legal document called a Statutory Instrument is published, detailing the route of the road, before it can be built. The dates given on these Statutory Instruments relate to when the document was published, and not when the road was built. Provided below is an incomplete list of the Statutory Instruments relating to the route of the M6.


title: 3D rotation group

text: In mechanics and geometry, the 3D rotation group, often denoted SO(3), is the group of all rotations about the origin of three-dimensional Euclidean space formula_1 under the operation of composition.


title: 3D rotation group

text: By definition, a rotation about the origin is a transformation that preserves the origin, Euclidean distance (so it is an isometry), and orientation (i.e., "handedness" of space). Composing two rotations results in another rotation, every rotation has a unique inverse rotation, and the identity map satisfies the definition of a rotation. Owing to the above properties (along composite rotations' associative property), the set of all rotations is a group under composition.


title: 3D rotation group

text: Every non-trivial rotation is determined by its axis of rotation (a line through the origin) and its angle of rotation. Rotations are not commutative (for example, rotating "R" 90° in the x-y plane followed by "S" 90° in the y-z plane is not the same as "S" followed by "R"), making the 3D rotation group a nonabelian group. Moreover, the rotation group has a natural structure as a manifold for which the group operations are smoothly differentiable, so it is in fact a Lie group. It is compact and has dimension 3.


title: 3D rotation group

text: Rotations are linear transformations of formula_1 and can therefore be represented by matrices once a basis of formula_1 has been chosen. Specifically, if we choose an orthonormal basis of formula_1, every rotation is described by an orthogonal 3 × 3 matrix (i.e., a 3 × 3 matrix with real entries which, when multiplied by its transpose, results in the identity matrix) with determinant 1. The group SO(3) can therefore be identified with the group of these matrices under matrix multiplication. These matrices are known as "special orthogonal matrices", explaining the notation SO(3).


title: 3D rotation group

text: The group SO(3) is used to describe the possible rotational symmetries of an object, as well as the possible orientations of an object in space. Its representations are important in physics, where they give rise to the elementary particles of integer spin.


title: 3D rotation group

text: Besides just preserving length, rotations also preserve the angles between vectors. This follows from the fact that the standard dot product between two vectors u and v can be written purely in terms of length:


title: 3D rotation group

text: It follows that every length-preserving linear transformation in formula_1 preserves the dot product, and thus the angle between vectors. Rotations are often defined as linear transformations that preserve the inner product on formula_1, which is equivalent to requiring them to preserve length. See classical group for a treatment of this more general approach, where appears as a special case.


title: 3D rotation group

text: Every rotation maps an orthonormal basis of formula_1 to another orthonormal basis. Like any linear transformation of finite-dimensional vector spaces, a rotation can always be represented by a matrix. Let be a given rotation. With respect to the standard basis of formula_1 the columns of are given by . Since the standard basis is orthonormal, and since preserves angles and length, the columns of form another orthonormal basis. This orthonormality condition can be expressed in the form


title: 3D rotation group

text: where denotes the transpose of and is the identity matrix. Matrices for which this property holds are called orthogonal matrices. The group of all orthogonal matrices is denoted , and consists of all proper and improper rotations.


title: 3D rotation group

text: In addition to preserving length, proper rotations must also preserve orientation. A matrix will preserve or reverse orientation according to whether the determinant of the matrix is positive or negative. For an orthogonal matrix , note that implies , so that . The subgroup of orthogonal matrices with determinant is called the "special orthogonal group", denoted .


title: 3D rotation group

text: Thus every rotation can be represented uniquely by an orthogonal matrix with unit determinant. Moreover, since composition of rotations corresponds to matrix multiplication, the rotation group is isomorphic to the special orthogonal group .


title: 3D rotation group

text: Improper rotations correspond to orthogonal matrices with determinant , and they do not form a group because the product of two improper rotations is a proper rotation.


title: 3D rotation group

text: The rotation group is a group under function composition (or equivalently the product of linear transformations). It is a subgroup of the general linear group consisting of all invertible linear transformations of the real 3-space formula_1.


title: 3D rotation group

text: Furthermore, the rotation group is nonabelian. That is, the order in which rotations are composed makes a difference. For example, a quarter turn around the positive "x"-axis followed by a quarter turn around the positive "y"-axis is a different rotation than the one obtained by first rotating around "y" and then "x".


title: 3D rotation group

text: The orthogonal group, consisting of all proper and improper rotations, is generated by reflections. Every proper rotation is the composition of two reflections, a special case of the Cartan–Dieudonné theorem.


title: 3D rotation group

text: Every nontrivial proper rotation in 3 dimensions fixes a unique 1-dimensional linear subspace of formula_1 which is called the "axis of rotation" (this is Euler's rotation theorem). Each such rotation acts as an ordinary 2-dimensional rotation in the plane orthogonal to this axis. Since every 2-dimensional rotation can be represented by an angle "φ", an arbitrary 3-dimensional rotation can be specified by an axis of rotation together with an angle of rotation about this axis. (Technically, one needs to specify an orientation for the axis and whether the rotation is taken to be clockwise or counterclockwise with respect to this orientation).


title: 3D rotation group

text: Given a unit vector n in formula_1 and an angle "φ", let "R"("φ", n) represent a counterclockwise rotation about the axis through n (with orientation determined by n). Then


title: 3D rotation group

text: Using these properties one can show that any rotation can be represented by a unique angle "φ" in the range 0 ≤ φ ≤ and a unit vector n such that


title: 3D rotation group

text: In the next section, this representation of rotations is used to identify SO(3) topologically with three-dimensional real projective space.


title: 3D rotation group

text: Consider the solid ball in formula_1 of radius (that is, all points of formula_1 of distance or less from the origin). Given the above, for every point in this ball there is a rotation, with axis through the point and the origin, and rotation angle equal to the distance of the point from the origin. The identity rotation corresponds to the point at the center of the ball. Rotation through angles between 0 and − correspond to the point on the same axis and distance from the origin but on the opposite side of the origin. The one remaining issue is that the two rotations through and through − are the same. So we identify (or "glue together") antipodal points on the surface of the ball. After this identification, we arrive at a topological space homeomorphic to the rotation group.


title: 3D rotation group

text: Indeed, the ball with antipodal surface points identified is a smooth manifold, and this manifold is diffeomorphic to the rotation group. It is also diffeomorphic to the real 3-dimensional projective space formula_18 so the latter can also serve as a topological model for the rotation group.


title: 3D rotation group

text: These identifications illustrate that SO(3) is connected but not simply connected. As to the latter, in the ball with antipodal surface points identified, consider the path running from the "north pole" straight through the interior down to the south pole. This is a closed loop, since the north pole and the south pole are identified. This loop cannot be shrunk to a point, since no matter how you deform the loop, the start and end point have to remain antipodal, or else the loop will "break open". In terms of rotations, this loop represents a continuous sequence of rotations about the "z"-axis starting (by example) at identity (center of ball), through south pole, jump to north pole and ending again at the identity rotation (i.e., a series of rotation through an angle "φ" where "φ" runs from 0 to 2).


title: 3D rotation group

text: Surprisingly, if you run through the path twice, i.e., run from north pole down to south pole, jump back to the north pole (using the fact that north and south poles are identified), and then again run from north pole down to south pole, so that "φ" runs from 0 to 4, you get a closed loop which "can" be shrunk to a single point: first move the paths continuously to the ball's surface, still connecting north pole to south pole twice. The second path can then be mirrored over to the antipodal side without changing the path at all. Now we have an ordinary closed loop on the surface of the ball, connecting the north pole to itself along a great circle. This circle can be shrunk to the north pole without problems. The plate trick and similar tricks demonstrate this practically.


title: 3D rotation group

text: The same argument can be performed in general, and it shows that the fundamental group of SO(3) is the cyclic group of order 2 (a fundamental group with two elements). In physics applications, the non-triviality (more than one element) of the fundamental group allows for the existence of objects known as spinors, and is an important tool in the development of the spin–statistics theorem.


title: 3D rotation group

text: The universal cover of SO(3) is a Lie group called Spin(3). The group Spin(3) is isomorphic to the special unitary group SU(2); it is also diffeomorphic to the unit 3-sphere "S" and can be understood as the group of versors (quaternions with absolute value 1). The connection between quaternions and rotations, commonly exploited in computer graphics, is explained in quaternions and spatial rotations. The map from "S" onto SO(3) that identifies antipodal points of "S" is a surjective homomorphism of Lie groups, with kernel {±1}. Topologically, this map is a two-to-one covering map. (See the plate trick.)


title: 3D rotation group

text: In this section, we give two different constructions of a two-to-one and surjective homomorphism of SU(2) onto SO(3).


title: 3D rotation group

text: Let us now identify formula_1 with the span of formula_27. One can then verify that if formula_28 is in formula_1 and formula_30 is a unit quaternion, then


title: 3D rotation group

text: Furthermore, the map formula_32 is a rotation of formula_33 Moreover, formula_34 is the same as formula_35. This means that there is a homomorphism from quaternions of unit norm to the 3D rotation group .


title: 3D rotation group

text: This is a rotation around the vector by an angle , where and . The proper sign for is implied, once the signs of the axis components are fixed. The is apparent since both and map to the same .


title: 3D rotation group

text: can, barring the north pole , be put into one-to-one bijection with points on the plane defined by , see figure. The map is called stereographic projection.


title: 3D rotation group

text: If is a rotation, then it will take points on to points on by its standard action on the embedding space formula_33 By composing this action with one obtains a transformation of ,


title: 3D rotation group

text: It turns out that represented in this way by can be expressed as a matrix (where the notation is recycled to use the same name for the matrix as for the transformation of formula_49 it represents). To identify this matrix, consider first a rotation about the through an angle ,


title: 3D rotation group

text: which, unsurprisingly, is a rotation in the complex plane. In an analogous way, if is a rotation about the through an angle , then


title: 3D rotation group

text: These two rotations, formula_56 thus correspond to bilinear transforms of , namely, they are examples of Möbius transformations.


title: 3D rotation group

text: The rotations, formula_58 generate all of and the composition rules of the Möbius transformations show that any composition of formula_58 translates to the corresponding composition of Möbius transformations. The Möbius transformations can be represented by matrices


title: 3D rotation group

text: For the same reason, the matrix is "not" uniquely defined since multiplication by has no effect on either the determinant or the Möbius transformation. The composition law of Möbius transformations follow that of the corresponding matrices. The conclusion is that each Möbius transformation corresponds to two matrices .


title: 3D rotation group

text: With the substitutions, assumes the form of the right hand side (RHS) of (), which corresponds under to a matrix on the form of the RHS of () with the same . In terms of the complex parameters ,


title: 3D rotation group

text: To verify this, substitute for the elements of the matrix on the RHS of (). After some manipulation, the matrix assumes the form of the RHS of ().


title: 3D rotation group

text: just described is a smooth, and surjective group homomorphism. It is hence an explicit description of the universal covering space of from the universal covering group .


title: 3D rotation group

text: Associated with every Lie group is its Lie algebra, a linear space of the same dimension as the Lie group, closed under a bilinear alternating product called the Lie bracket. The Lie algebra of is denoted by formula_66 and consists of all skew-symmetric matrices. This may be seen by differentiating the orthogonality condition, . The Lie bracket of two elements of formula_66 is, as for the Lie algebra of every matrix group, given by the matrix commutator, , which is again a skew-symmetric matrix. The Lie algebra bracket captures the essence of the Lie group product in a sense made precise by the Baker–Campbell–Hausdorff formula.


title: 3D rotation group

text: The elements of formula_66 are the "infinitesimal generators" of rotations, i.e., they are the elements of the tangent space of the manifold SO(3) at the identity element. If formula_69 denotes a counterclockwise rotation with angle φ about the axis specified by the unit vector formula_70 then


title: 3D rotation group

text: This can be used to show that the Lie algebra formula_66 (with commutator) is isomorphic to the Lie algebra formula_1 (with cross product). Under this isomorphism, an Euler vector formula_74 corresponds to the linear map formula_75 defined by formula_76


title: 3D rotation group

text: which agree with the relations of the three standard unit vectors of formula_1 under the cross product.


title: 3D rotation group

text: This identification is sometimes called the hat-map. Under this identification, the formula_66 bracket corresponds in formula_1 to the cross product,


title: 3D rotation group

text: where the left-hand side we have ordinary matrix multiplication. This implies formula_86 is in the null space of the skew-symmetric matrix with which it is identified, because formula_89


title: 3D rotation group

text: In Lie algebra representations, the group SO(3) is compact and simple of rank 1, and so it has a single independent Casimir element, a quadratic invariant function of the three generators which commutes with all of them. The Killing form for the rotation group is just the Kronecker delta, and so this Casimir invariant is simply the sum of the squares of the generators, formula_90 of the algebra


title: 3D rotation group

text: For unitary irreducible representations , the eigenvalues of this invariant are real and discrete, and characterize each representation, which is finite dimensional, of dimensionality formula_93. That is, the eigenvalues of this Casimir operator are


title: 3D rotation group

text: So, the 3 × 3 generators L displayed above act on the triplet (spin 1) representation, while the 2 × 2 generators below, t, act on the doublet (spin-1/2) representation. By taking Kronecker products of with itself repeatedly, one may construct all higher irreducible representations . That is, the resulting generators for higher spin systems in three spatial dimensions, for arbitrarily large , can be calculated using these spin operators and ladder operators.


title: 3D rotation group

text: In quantum mechanics, the Casimir invariant is the "angular-momentum-squared" operator; integer values of spin characterize bosonic representations, while half-integer values fermionic representations. The antihermitian matrices used above are utilized as spin operators, after they are multiplied by , so they are now hermitian (like the Pauli matrices). Thus, in this language,


title: 3D rotation group

text: Note, however, how these are in an equivalent, but different basis, the spherical basis, than the above L in the Cartesian basis.


title: 3D rotation group

text: The Pauli matrices abide by the physicists' convention for Lie algebras. In that convention, Lie algebra elements are multiplied by , the exponential map (below) is defined with an extra factor of in the exponent and the structure constants remain the same, but the "definition" of them acquires a factor of . Likewise, commutation relations acquire a factor of . The commutation relations for the formula_110 are


title: 3D rotation group

text: where is the totally anti-symmetric symbol with . The isomorphism between formula_66 and formula_106 can be set up in several ways. For later convenience, formula_66 and formula_106 are identified by mapping


title: 3D rotation group

text: The exponential map for , is, since is a matrix Lie group, defined using the standard matrix exponential series,


title: 3D rotation group

text: For any skew-symmetric matrix , is always in . The proof uses the elementary properties of the matrix exponential


title: 3D rotation group

text: since the matrices and commute, this can be easily proven with the skew-symmetric matrix condition. This is not enough to show that is the corresponding Lie algebra for , and shall be proven separately.


title: 3D rotation group

text: The level of difficulty of proof depends on how a matrix group Lie algebra is defined. defines the Lie algebra as the set of matrices


title: 3D rotation group

text: in which case it is trivial. uses for a definition derivatives of smooth curve segments in through the identity taken at the identity, in which case it is harder.


title: 3D rotation group

text: For a fixed , is a one-parameter subgroup along a geodesic in . That this gives a one-parameter subgroup follows directly from properties of the exponential map.


title: 3D rotation group

text: The exponential map provides a diffeomorphism between a neighborhood of the origin in the and a neighborhood of the identity in the . For a proof, see Closed subgroup theorem.


title: 3D rotation group

text: The exponential map is surjective. This follows from the fact that every , since every rotation leaves an axis fixed (Euler's rotation theorem), and is conjugate to a block diagonal matrix of the form


title: 3D rotation group

text: As shown above, every element is associated with a vector , where is a unit magnitude vector. Since is in the null space of , if one now rotates to a new basis, through some other orthogonal matrix , with as the axis, the final column and row of the rotation matrix in the new basis will be zero.


title: 3D rotation group

text: Thus, we know in advance from the formula for the exponential that must leave fixed. It is mathematically impossible to supply a straightforward formula for such a basis as a function of , because its existence would violate the hairy ball theorem; but direct exponentiation is possible, and yields


title: 3D rotation group

text: where formula_124 and formula_125. This is recognized as a matrix for a rotation around axis by the angle : cf. Rodrigues' rotation formula.


title: 3D rotation group

text: Given , let formula_126 denote the antisymmetric part and let formula_127 Then, the logarithm of is given by


title: 3D rotation group

text: formula_130 is doubly covered by the group of unit quaternions, which is isomorphic to the 3-sphere. Since the Haar measure on the unit quaternions is just the 3-area measure in 4 dimensions, the Haar measure on formula_130 is just the pushforward of the 3-area measure.


title: 3D rotation group

text: Consequently, generating a uniformly random rotation in formula_1 is equivalent to generating a uniformly random point on the 3-sphere. This can be accomplished by the followingformula_133


title: 3D rotation group

text: Suppose and in the Lie algebra are given. Their exponentials, and , are rotation matrices, which can be multiplied. Since the exponential map is a surjection, for some in the Lie algebra, , and one may tentatively write


title: 3D rotation group

text: for some expression in and . When and commute, then , mimicking the behavior of complex exponentiation.


title: 3D rotation group

text: The general case is given by the more elaborate BCH formula, a series expansion of nested Lie brackets. For matrices, the Lie bracket is the same operation as the commutator, which monitors lack of commutativity in multiplication. This general expansion unfolds as follows,


title: 3D rotation group

text: The inner product is the Hilbert–Schmidt inner product and the norm is the associated norm. Under the hat-isomorphism,


title: 3D rotation group

text: The above identity holds for all faithful representations of . The kernel of a Lie algebra homomorphism is an ideal, but , being simple, has no nontrivial ideals and all nontrivial representations are hence faithful. It holds in particular in the doublet or spinor representation. The same explicit formula thus follows in a simpler way through Pauli matrices, cf. the 2×2 derivation for SU(2).


title: 3D rotation group

text: The Pauli vector version of the same BCH formula is the somewhat simpler group composition law of SU(2),


title: 3D rotation group

text: For uniform normalization of the generators in the Lie algebra involved, express the Pauli matrices in terms of -matrices, , so that


title: 3D rotation group

text: The quaternion formulation of the composition of two rotations R and R also yields directly the rotation axis and angle of the composite rotation R = RR.


title: 3D rotation group

text: Let the quaternion associated with a spatial rotation R is constructed from its rotation axis S and the rotation angle "φ" this axis. The associated quaternion is given by,


title: 3D rotation group

text: Then the composition of the rotation R with R is the rotation R = RR with rotation axis and angle defined by the product of the quaternions


title: 3D rotation group

text: This is Rodrigues' formula for the axis of a composite rotation defined in terms of the axes of the two rotations. He derived this formula in 1840 (see page 408).


title: 3D rotation group

text: The three rotation axes A, B, and C form a spherical triangle and the dihedral angles between the planes formed by the sides of this triangle are defined by the rotation angles.


title: 3D rotation group

text: The matrices in the Lie algebra are not themselves rotations; the skew-symmetric matrices are derivatives. An actual "differential rotation", or "infinitesimal rotation matrix" has the form


title: 3D rotation group

text: These matrices do not satisfy all the same properties as ordinary finite rotation matrices under the usual treatment of infinitesimals . To understand what this means, consider


title: 3D rotation group

text: differing from an identity matrix by second order infinitesimals, discarded here. So, to first order, an infinitesimal rotation matrix is an orthogonal matrix.


title: 3D rotation group

text: Again discarding second order effects, note that the angle simply doubles. This hints at the most essential difference in behavior, which we can exhibit with the assistance of a second infinitesimal rotation,


title: 3D rotation group

text: Since formula_163 is second-order, we discard it: thus, to first order, multiplication of infinitesimal rotation matrices is "commutative". In fact,


title: 3D rotation group

text: again to first order. In other words, the order in which infinitesimal rotations are applied is irrelevant.


title: 3D rotation group

text: This useful fact makes, for example, derivation of rigid body rotation relatively simple. But one must always be careful to distinguish (the first order treatment of) these infinitesimal rotation matrices from both finite rotation matrices and from Lie algebra elements. When contrasting the behavior of finite rotation matrices in the BCH formula above with that of infinitesimal rotation matrices, where all the commutator terms will be second order infinitesimals one finds a bona fide vector space. Technically, this dismissal of any second order terms amounts to Group contraction.


title: 3D rotation group

text: The group of three-dimensional Euclidean rotations has an infinite-dimensional representation on the Hilbert space


title: 3D rotation group

text: where formula_166 are spherical harmonics. Its elements are square integrable complex-valued functions on the sphere. The inner product on this space is given by


title: 3D rotation group

text: If is an arbitrary square integrable function defined on the unit sphere , then it can be expressed as


title: 3D rotation group

text: The can be obtained from the of above using Clebsch–Gordan decomposition, but they are more easily directly expressed as an exponential of an odd-dimensional -representation (the 3-dimensional one is exactly ). In this case the space decomposes neatly into an infinite direct sum of irreducible odd finite-dimensional representations according to


title: 3D rotation group

text: This is characteristic of infinite-dimensional unitary representations of . If is an infinite-dimensional unitary representation on a separable Hilbert space, then it decomposes as a direct sum of finite-dimensional unitary representations. Such a representation is thus never irreducible. All irreducible finite-dimensional representations can be made unitary by an appropriate choice of inner product,


title: 3D rotation group

text: where the integral is the unique invariant integral over normalized to , here expressed using the Euler angles parametrization. The inner product inside the integral is any inner product on .


title: 3D rotation group

text: The rotation group generalizes quite naturally to "n"-dimensional Euclidean space, formula_168 with its standard Euclidean structure. The group of all proper and improper rotations in "n" dimensions is called the orthogonal group O("n"), and the subgroup of proper rotations is called the special orthogonal group SO("n"), which is a Lie group of dimension .


title: 3D rotation group

text: In special relativity, one works in a 4-dimensional vector space, known as Minkowski space rather than 3-dimensional Euclidean space. Unlike Euclidean space, Minkowski space has an inner product with an indefinite signature. However, one can still define "generalized rotations" which preserve this inner product. Such generalized rotations are known as Lorentz transformations and the group of all such transformations is called the Lorentz group.


title: 3D rotation group

text: The rotation group SO(3) can be described as a subgroup of E(3), the Euclidean group of direct isometries of Euclidean formula_33 This larger group is the group of all motions of a rigid body: each of these is a combination of a rotation about an arbitrary axis and a translation, or put differently, a combination of an element of SO(3) and an arbitrary translation.


title: 3D rotation group

text: In general, the rotation group of an object is the symmetry group within the group of direct isometries; in other words, the intersection of the full symmetry group and the group of direct isometries. For chiral objects it is the same as the full symmetry group.


title: Vaginal delivery

text: A vaginal delivery is the birth of offspring in mammals (babies in humans) through the vagina (also called the "birth canal"). It is the most common method of childbirth worldwide. It is considered the preferred method of delivery, with lower morbidity and mortality than Caesarean sections (C-sections).


title: Vaginal delivery

text: 80% of births globally in 2021 were vaginal deliveries, with rates varying from 95% in sub-Saharan Africa to 45% in the Caribbean.


title: Vaginal delivery

text: Labor is characterized by uterine contractions which push the fetus through the birth canal and results in delivery. Labor is divided into three stages.


title: Vaginal delivery

text: Complications of vaginal delivery can be grouped into the following criteria; failure to progress, abnormal fetal heart rate tracing, intrapartum hemorrhage, and post-partum hemorrhage.


title: Vaginal delivery

text: "Failure to progress" occurs when the labor process slows or stops entirely, indicated by slowed cervical dilation. Factors that place a woman's pregnancy at higher risk include advanced maternal age, Premature Rupture of Membranes (PROM) and induction of labor. Oxytocin, a uterotonic agent, can be administered to augment labor. Cesarean section is also commonly considered when the pregnancy fails to progress. With a cesarean section, there is a higher chance that the uterus will become infected or that thromboembolic complications will occur. There is also a higher chance of death.


title: Vaginal delivery

text: "Abnormal fetal heart tracing" suggests that the fetus's heart rate has slowed during labor due to head compression, cord compression, hypoxemia or anemia. Uterine tachysystole, the most common adverse effect of oxytocin (usually as a result of a problematic dosage), can result in nonreassuring fetal heart tracing. It can usually be reversed when oxytocin infusion is decreased or stopped. If the abnormal fetal heart rate persists, and uterine tachysystole continues, tocolytic remedies, such as terbutaline, may be used. Afterward, if beneficial and uterine tone has returned to baseline and fetal status is stable, oxytocin as a labor augmenting agent may be resumed. The persistence of an abnormal fetal heart rate may also indicate that a cesarean section is necessary.


title: Vaginal delivery

text: "Intrapartum hemorrhage" is characterized by the presence of copious blood during labor. The bleeding may be due to placental abruption, uterine rupture, placenta accrete, undiagnosed placenta previa, or vasa previa. Cesarean section is indicated.


title: Vaginal delivery

text: "Post-partum hemorrhage" is defined by the loss of at least 1,000 mL of blood accompanied with symptoms of hypovolemia within 24 hours after delivery. Typically, the first symptom is excessive bleeding accompanied by tachycardia. Significant loss of blood may also result in hypotension, nausea, dyspnea, and chest pain. It is estimated that between 3% to 5% of women giving birth vaginally will experience post-partum hemorrhage. Risk factors include fetal macrosomia, pre-eclampsia, and prolonged labor. Prevention consists of administering oxytocin (Pitocin) at delivery and early umbilical cord clamping. Post-partum hemorrhage is usually attributed to uterus atony, when the uterus fails to contract after delivering the baby.


title: Vaginal delivery

text: As a result of discrepancies in diagnostic criteria and human variability, there is wide variation in data on maternal and fetal death associated with poor progress.


title: Vaginal delivery

text: Spontaneous vaginal delivery at term is the preferred outcome of pregnancy, and according to the International Federation of Gynecology and Obstetrics, will be recommended if there are no evidence-based clinical indications for cesarean section. However, there are some contraindications for vaginal delivery that would result in conversion to cesarean delivery. The decision to switch to cesarean delivery is made by the health care provider and mother, and is sometimes delayed until the mother is in labor.


title: Vaginal delivery

text: "Breech birth" presentations occur when the fetus' buttocks or lower extremities are poised to deliver before the fetus' upper extremities or head. The three types of breech positions are footling breech, frank breech, and complete breech. These births occur in 3% to 4% of all term pregnancies. They usually result in cesarean sections because it is more difficult to deliver the baby through the birth canal and there is a lack of expertise in vaginal breech delivery and therefore fewer vaginal breech deliveries performed. It is also associated with cord prolapse and an elevated risk for birth defects of breech babies. Controversy and debate surround the topic due to different views on the preferred route of delivery when breech presentation occurs. Some health professionals believe that vaginal breech delivery can be a safe alternative to planned cesarean in certain instances.


title: Vaginal delivery

text: "Complete placenta previa" occurs when the placenta covers the opening of the cervix. If placenta previa is present at the time of delivery, vaginal delivery is contraindicated because the placenta is blocking the fetus’ passageway to the vaginal canal.


title: Vaginal delivery

text: "Herpes simplex virus with active genital lesions or prodromal symptoms" is a contraindication for vaginal delivery so as to avoid mother-fetal transfer of HSV lesions.


title: Vaginal delivery

text: "Untreated human immunodeficiency virus (HIV) infection" is a contraindication for vaginal delivery to avoid mother-fetal transfer of human immunodeficiency virus.


title: Seaborgium

text: Seaborgium is a synthetic chemical element with the symbol Sg and atomic number 106. It is named after the American nuclear chemist Glenn T. Seaborg. As a synthetic element, it can be created in a laboratory but is not found in nature. It is also radioactive; the most stable known isotope, Sg, has a half-life of approximately 14 minutes.


title: Seaborgium

text: In the periodic table of the elements, it is a d-block transactinide element. It is a member of the 7th period and belongs to the group 6 elements as the fourth member of the 6d series of transition metals. Chemistry experiments have confirmed that seaborgium behaves as the heavier homologue to tungsten in group 6. The chemical properties of seaborgium are characterized only partly, but they compare well with the chemistry of the other group 6 elements.


title: Seaborgium

text: In 1974, a few atoms of seaborgium were produced in laboratories in the Soviet Union and in the United States. The priority of the discovery and therefore the naming of the element was disputed between Soviet and American scientists, and it was not until 1997 that the International Union of Pure and Applied Chemistry (IUPAC) established seaborgium as the official name for the element. It is one of only two elements named after a living person at the time of naming, the other being oganesson, element 118.


title: Seaborgium

text: Following claims of the observation of elements 104 and 105 in 1970 by Albert Ghiorso et al. at the Lawrence Livermore National Laboratory, a search for element 106 using oxygen-18 projectiles and the previously used californium-249 target was conducted. Several 9.1 MeV alpha decays were reported and are now thought to originate from element 106, though this was not confirmed at the time. In 1972, the HILAC accelerator received equipment upgrades, preventing the team from repeating the experiment, and data analysis was not done during the shutdown. This reaction was tried again several years later, in 1974, and the Berkeley team realized that their new data agreed with their 1971 data, to the astonishment of Ghiorso. Hence, element 106 could have actually been discovered in 1971 if the original data was analyzed more carefully.


title: Seaborgium

text: Two groups claimed discovery of the element. Unambiguous evidence of element 106 was first reported in 1974 by a Russian research team in Dubna led by Yuri Oganessian, in which targets of lead-208 and lead-207 were bombarded with accelerated ions of chromium-54. In total, fifty-one spontaneous fission events were observed with a half-life between four and ten milliseconds. After having ruled out nucleon transfer reactions as a cause for these activities, the team concluded that the most likely cause of the activities was the spontaneous fission of isotopes of element 106. The isotope in question was first suggested to be seaborgium-259, but was later corrected to seaborgium-260.


title: Seaborgium

text: A few months later in 1974, researchers including Glenn T. Seaborg, Carol Alonso and Albert Ghiorso at the University of California, Berkeley, and E. Kenneth Hulet from the Lawrence Livermore National Laboratory, also synthesized the element by bombarding a californium-249 target with oxygen-18 ions, using equipment similar to that which had been used for the synthesis of element 104 five years earlier, observing at least seventy alpha decays, seemingly from the isotope seaborgium-263m with a half-life of seconds. The alpha daughter rutherfordium-259 and granddaughter nobelium-255 had previously been synthesised and the properties observed here matched with those previously known, as did the intensity of their production. The cross-section of the reaction observed, 0.3 nanobarns, also agreed well with theoretical predictions. These bolstered the assignment of the alpha decay events to seaborgium-263m.


title: Seaborgium

text: A dispute thus arose from the initial competing claims of discovery, though unlike the case of the synthetic elements up to element 105, neither team of discoverers chose to announce proposed names for the new elements, thus averting an element naming controversy temporarily. The dispute on discovery, however, dragged on until 1992, when the IUPAC/IUPAP Transfermium Working Group (TWG), formed to put an end to the controversy by making conclusions regarding discovery claims for elements 101 to 112, concluded that the Soviet synthesis of seaborgium-260 was not convincing enough, "lacking as it is in yield curves and angular selection results", whereas the American synthesis of seaborgium-263 was convincing due to its being firmly anchored to known daughter nuclei. As such, the TWG recognised the Berkeley team as official discoverers in their 1993 report.


title: Seaborgium

text: Seaborg had previously suggested to the TWG that if Berkeley was recognised as the official discoverer of elements 104 and 105, they might propose the name "kurchatovium" (symbol Kt) for element 106 to honour the Dubna team, which had proposed this name for element 104 after Igor Kurchatov, the former head of the Soviet nuclear research programme. However, due to the worsening relations between the competing teams after the publication of the TWG report (because the Berkeley team vehemently disagreed with the TWG's conclusions, especially regarding element 104), this proposal was dropped from consideration by the Berkeley team. After being recognized as official discoverers, the Berkeley team started deciding on a name in earnest:


title: Seaborgium

text: The name "seaborgium" and symbol "Sg" were announced at the 207th national meeting of the American Chemical Society in March 1994 by Kenneth Hulet, one of the co-discovers. However, IUPAC resolved in August 1994 that an element could not be named after a living person, and Seaborg was still alive at the time. Thus, in September 1994, IUPAC recommended a set of names in which the names proposed by the three laboratories (the third being the GSI Helmholtz Centre for Heavy Ion Research in Darmstadt, Germany) with competing claims to the discovery for elements 104 to 109 were shifted to various other elements, in which "rutherfordium" (Rf), the Berkeley proposal for element 104, was shifted to element 106, with "seaborgium" being dropped entirely as a name.


title: Seaborgium

text: This decision ignited a firestorm of worldwide protest for disregarding the historic discoverer's right to name new elements, and against the new retroactive rule against naming elements after living persons; the American Chemical Society stood firmly behind the name "seaborgium" for element 106, together with all the other American and German naming proposals for elements 104 to 109, approving these names for its journals in defiance of IUPAC. At first, IUPAC defended itself, with an American member of its committee writing: "Discoverers don't have a right to name an element. They have a right to suggest a name. And, of course, we didn't infringe on that at all." However, Seaborg responded:


title: Seaborgium

text: Bowing to public pressure, IUPAC proposed a different compromise in August 1995, in which the name "seaborgium" was reinstated for element 106 in exchange for the removal of all but one of the other American proposals, which met an even worse response. Finally, IUPAC rescinded these previous compromises and made a final, new recommendation in August 1997, in which the American and German proposals for elements 104 to 109 were all adopted, including "seaborgium" for element 106, with the single exception of element 105, named "dubnium" to recognise the contributions of the Dubna team to the experimental procedures of transactinide synthesis. This list was finally accepted by the American Chemical Society, which wrote:


title: Seaborgium

text: Superheavy elements such as seaborgium are produced by bombarding lighter elements in particle accelerators that induces fusion reactions. Whereas most of the isotopes of seaborgium can be synthesized directly this way, some heavier ones have only been observed as decay products of elements with higher atomic numbers.


title: Seaborgium

text: Depending on the energies involved, fusion reactions that generate superheavy elements are separated into "hot" and "cold". In hot fusion reactions, very light, high-energy projectiles are accelerated toward very heavy targets (actinides), giving rise to compound nuclei at high excitation energy (~40–50 MeV) that may either fission or evaporate several (3 to 5) neutrons. In cold fusion reactions, the produced fused nuclei have a relatively low excitation energy (~10–20 MeV), which decreases the probability that these products will undergo fission reactions. As the fused nuclei cool to the ground state, they require emission of only one or two neutrons, and thus, allows for the generation of more neutron-rich products. The latter is a distinct concept from that of where nuclear fusion claimed to be achieved at room temperature conditions (see cold fusion).


title: Seaborgium

text: Seaborgium has no stable or naturally occurring isotopes. Several radioactive isotopes have been synthesized in the laboratory, either by fusing two atoms or by observing the decay of heavier elements. Thirteen different isotopes of seaborgium have been reported with atomic masses 258–269 and 271, three of which, seaborgium-261, 263, and 265, have known metastable states. All of these decay only through alpha decay and spontaneous fission, with the single exception of seaborgium-261 that can also undergo electron capture to dubnium-261.


title: Seaborgium

text: There is a trend toward increasing half-lives for the heavier isotopes; thus the heaviest three known isotopes, Sg, Sg, and Sg, are also the longest-lived, having half-lives in minutes. Some other isotopes in this region are predicted to have comparable or even longer half-lives. Additionally, Sg, Sg, and Sg have half-lives measured in seconds. All the remaining isotopes have half-lives measured in milliseconds, with the exception of the shortest-lived isotope, Sg, with a half-life of only 92 microseconds.


title: Seaborgium

text: The proton-rich isotopes from Sg to Sg were directly produced by cold fusion; all heavier isotopes were produced from the repeated alpha decay of the heavier elements hassium, darmstadtium, and flerovium, with the exceptions of the isotopes Sg, Sg, Sg, and Sg, which were directly produced by hot fusion through irradiation of actinide targets. The twelve isotopes of seaborgium have half-lives ranging from 92 microseconds for Sg to 14 minutes for Sg.


title: Seaborgium

text: Very few properties of seaborgium or its compounds have been measured; this is due to its extremely limited and expensive production and the fact that seaborgium (and its parents) decays very quickly. A few singular chemistry-related properties have been measured, but properties of seaborgium metal remain unknown and only predictions are available.


title: Seaborgium

text: Seaborgium is expected to be a solid under normal conditions and assume a body-centered cubic crystal structure, similar to its lighter congener tungsten. Early predictions estimated that it should be a very heavy metal with density around 35.0 g/cm, but calculations in 2011 and 2013 predicted a somewhat lower value of 23–24 g/cm.


title: Seaborgium

text: Seaborgium is the fourth member of the 6d series of transition metals and the heaviest member of group 6 in the periodic table, below chromium, molybdenum, and tungsten. All the members of the group form a diversity of oxoanions. They readily portray their group oxidation state of +6, although this is highly oxidising in the case of chromium, and this state becomes more and more stable to reduction as the group is descended: indeed, tungsten is the last of the 5d transition metals where all four 5d electrons participate in metallic bonding. As such, seaborgium should have +6 as its most stable oxidation state, both in the gas phase and in aqueous solution, and this is the only oxidation state that is experimentally known for it; the +5 and +4 states should be less stable, and the +3 state, the most common for chromium, would be the least stable for seaborgium.


title: Seaborgium

text: This stabilisation of the highest oxidation state occurs in the early 6d elements because of the similarity between the energies of the 6d and 7s orbitals, since the 7s orbitals are relativistically stabilised and the 6d orbitals are relativistically destabilised. This effect is so large in the seventh period that seaborgium is expected to lose its 6d electrons before its 7s electrons (Sg, [Rn]5f6d7s; Sg, [Rn]5f6d7s; Sg, [Rn]5f6d7s; Sg, [Rn]5f6d; Sg, [Rn]5f). Because of the great destabilisation of the 7s orbital, Sg should be even more unstable than W and should be very readily oxidised to Sg. The predicted ionic radius of the hexacoordinate Sg ion is 65 pm, while the predicted atomic radius of seaborgium is 128 pm. Nevertheless, the stability of the highest oxidation state is still expected to decrease as Lr > Rf > Db > Sg. Some predicted standard reduction potentials for seaborgium ions in aqueous acidic solution are as follows:


title: Seaborgium

text: Seaborgium should form a very volatile hexafluoride (SgF) as well as a moderately volatile hexachloride (SgCl), pentachloride (SgCl), and oxychlorides SgOCl and SgOCl. SgOCl is expected to be the most stable of the seaborgium oxychlorides and to be the least volatile of the group 6 oxychlorides, with the sequence MoOCl > WOCl > SgOCl. The volatile seaborgium(VI) compounds SgCl and SgOCl are expected to be unstable to decomposition to seaborgium(V) compounds at high temperatures, analogous to MoCl and MoOCl; this should not happen for SgOCl due to the much higher energy gap between the highest occupied and lowest unoccupied molecular orbitals, despite the similar Sg–Cl bond strengths (similarly to molybdenum and tungsten).


title: Seaborgium

text: Molybdenum and tungsten are very similar to each other and show important differences to the smaller chromium, and seaborgium is expected to follow the chemistry of tungsten and molybdenum quite closely, forming an even greater variety of oxoanions, the simplest among them being seaborgate, , which would form from the rapid hydrolysis of , although this would take place less readily than with molybdenum and tungsten as expected from seaborgium's greater size. Seaborgium should hydrolyse less readily than tungsten in hydrofluoric acid at low concentrations, but more readily at high concentrations, also forming complexes such as SgOF and : complex formation competes with hydrolysis in hydrofluoric acid.


title: Seaborgium

text: Experimental chemical investigation of seaborgium has been hampered due to the need to produce it one atom at a time, its short half-life, and the resulting necessary harshness of the experimental conditions. The isotope Sg and its isomer Sg are advantageous for radiochemistry: they are produced in the Cm(Ne,5n) reaction.


title: Seaborgium

text: In the first experimental chemical studies of seaborgium in 1995 and 1996, seaborgium atoms were produced in the reaction Cm(Ne,4n)Sg, thermalised, and reacted with an O/HCl mixture. The adsorption properties of the resulting oxychloride were measured and compared with those of molybdenum and tungsten compounds. The results indicated that seaborgium formed a volatile oxychloride akin to those of the other group 6 elements, and confirmed the decreasing trend of oxychloride volatility down group 6:


title: Seaborgium

text: In 2001, a team continued the study of the gas phase chemistry of seaborgium by reacting the element with O in a HO environment. In a manner similar to the formation of the oxychloride, the results of the experiment indicated the formation of seaborgium oxide hydroxide, a reaction well known among the lighter group 6 homologues as well as the pseudohomologue uranium.


title: Seaborgium

text: Predictions on the aqueous chemistry of seaborgium have largely been confirmed. In experiments conducted in 1997 and 1998, seaborgium was eluted from cation-exchange resin using a HNO/HF solution, most likely as neutral SgOF or the anionic complex ion [SgOF] rather than . In contrast, in 0.1 M nitric acid, seaborgium does not elute, unlike molybdenum and tungsten, indicating that the hydrolysis of [Sg(HO)] only proceeds as far as the cationic complex [Sg(OH)(HO)] or [Sg(OH)(HO)], while that of molybdenum and tungsten proceeds to neutral [MO(OH))].


title: Seaborgium

text: The only other oxidation state known for seaborgium other than the group oxidation state of +6 is the zero oxidation state. Similarly to its three lighter congeners, forming chromium hexacarbonyl, molybdenum hexacarbonyl, and tungsten hexacarbonyl, seaborgium has been shown in 2014 to also form seaborgium hexacarbonyl, Sg(CO). Like its molybdenum and tungsten homologues, seaborgium hexacarbonyl is a volatile compound that reacts readily with silicon dioxide.


title: Palace of Justice siege

text: The Palace of Justice siege was a 1985 attack on the Supreme Court of Colombia, in which members of the leftist M-19 guerrilla group took over the Palace of Justice in Bogotá and held the Supreme Court hostage, intending to hold a trial against President Belisario Betancur. The guerrilla group called themselves the "Iván Marino Ospina Company" after an M-19 commander who had been killed by the Colombian military on 28 August 1985. Hours later, after a military raid, the incident left almost half of the twenty-five Supreme Court Justices dead.


title: Palace of Justice siege

text: Drug dealers had issued death threats against the Supreme Court Justices since 1985, with the intention of forcing them to rule out the Extradition Treaty with the United States.


title: Palace of Justice siege

text: On 6 November 1985, at 11:35 a.m., three vehicles holding 35 guerrillas (25 men and 10 women) stormed the Palace of Justice of Colombia, entering through the basement. Meanwhile, another group of guerrillas disguised as civilians took over the first floor and the main entrance. The guerrillas killed security guards Eulogio Blanco and Gerardo Díaz Arbeláez and building manager Jorge Tadeo Mayo Castro.


title: Palace of Justice siege

text: Jorge Medina, a witness located in the basement at the start of the siege, said that "suddenly, the guerrillas entered the basement in a truck. They opened fire with their machine guns against everyone who was there". The official report judged that the guerrillas planned the takeover operation to be a 'bloody takeover'. According to these official sources the guerrillas "set out to shoot indiscriminately and detonate building-shaking bombs while chanting M19-praising battle cries."


title: Palace of Justice siege

text: The M-19 lost one guerrilla and a nurse during the initial raid on the building. After the guerrillas had neutralised the security personnel guarding the building, they installed armed posts at strategic places, such as the stairs and the fourth floor. A group of guerrillas led by Commander Luis Otero got to the fourth floor and kidnapped the President of the Supreme Court, Chief Justice Alfonso Reyes Echandía.


title: Palace of Justice siege

text: In the meantime many hostages took refuge in empty offices on the first floor, where they hid until around 2 pm.


title: Palace of Justice siege

text: The assailants took 300 people hostage, including the 24 justices and 20 other judges. The first hostage the guerrilla group asked for was the Supreme Court Justice and President of the Constitutional Court, then called "Sala Constitucional", Manuel Gaona Cruz, who was in charge of delivering the opinion of the court with regard to the constitutionality of the extradition treaty between Colombia and the United States.


title: Palace of Justice siege

text: About three hours after the initial seizure, army troops rescued about 200 hostages from the lower three floors of the building; the surviving gunmen and remaining hostages occupied the upper two floors.


title: Palace of Justice siege

text: A recording was delivered to a radio station soon after the seizure, saying that the M-19 group had taken over the building "in the name of peace and social justice". From the Supreme Court, the M-19 members demanded via telephone that President Belisario Betancur come to the Palace of Justice in order to stand trial and negotiate. The president refused and ordered an emergency cabinet session.


title: Palace of Justice siege

text: The M-19 rebels freed State Councillor Reynaldo Arciniegas at 8:30am, with a message for the government to allow the entry of the Red Cross and initiate dialogue. However, the assault on the Palace of Justice commenced later that morning.


title: Palace of Justice siege

text: The operation to retake the building was led by General Jesús Armando Arias Cabrales, commander of the Thirteenth Army Brigade in Bogotá; he appointed Colonel Alfonso Plazas, commander of an armored cavalry battalion, to personally oversee the operation. The retaking of the building began that day and ended on 7 November, when Army troops stormed the Palace of Justice, after having occupied some of the lower floors during the first day of the siege. After surrounding the building with EE-9 Cascavel armored cars and soldiers with automatic weapons, they stormed the building sometime after 2 pm. The EE-9s knocked down the building's massive doorway, and even made some direct hits against the structure's external walls.


title: Palace of Justice siege

text: The results of the tests carried out later by ballistics experts and investigators demonstrated that the most likely cause of the burning criminal records, containing proof and warrants against many criminals, was the recoil effect of the army's rockets and not part of M-19's actions. Tests proved that if fired by a soldier standing within twenty feet of wood-lined walls of the library that housed Colombian legal archives, the intense heat generated by the rocket's rear blast could have ignited the wooden paneling. In any event, in a shelved area stacked high with old papers, files, books, and newspapers, the quantity of explosives used by the military virtually guaranteed a conflagration." In total, over 6000 different documents were burned. The fire lasted about 2 days, even with efforts from firemen to try to smother the flames. An investigated theory to the "disappearance" of the missing entities in the siege is that they were charred in the fire, and were not able to be identified in any way, and without having been found, these entities are regarded as missing in action. This theory is still being studied in the different trials of the case.


title: Palace of Justice siege

text: 98 people died during the assault on the Palace. Those killed consisted of hostages, soldiers, and guerrillas, including their leader, Andrés Almarales, and four other senior commanders of M-19. After the raid, another Supreme Court justice died in a hospital after suffering a heart attack.


title: Palace of Justice siege

text: The siege of the Palace of Justice and the subsequent raid was one of the deadliest attacks in Colombia in its war with leftist rebels. The M-19 group was still a potent force after the raid, but was severely hampered by the deaths of five of its leaders. In March 1990, it signed a peace treaty with the government.


title: Palace of Justice siege

text: After the siege, firemen rushed to the site of the assault and smothered the few flames left in the palace. Other rescue groups assisted with removing debris and rubble left after the siege.


title: Palace of Justice siege

text: President Betancur went on national TV on the night of the 7th, saying he took full responsibility for the "terrible nightmare"; He offered condolences to the families of those who died, civilians and rebels, and said he would continue to look for a peaceful solution with the rebels. Exactly a week later, on 14 November, he would offer condolences for another tragedy: the eruption of the Nevado del Ruiz volcano, which killed 25,000 people in the Armero tragedy. "We have had one national tragedy after another", he said.


title: Palace of Justice siege

text: This siege led to the creation of the AFEUR unit within the Colombian Army to manage this kind of situation. Colombia's Armed Forces did not have antiterrorist units specifically trained for urban operations before the siege, and some partially blamed the outcome on the relative inexperience of the personnel assigned to the task.


title: Palace of Justice siege

text: Shortly after the siege, the U.S. and Colombian Justice Minister Enrique Parejo asserted that drug traffickers financed the operation in order to get rid of various criminal files that were lost during the event, hoping to avoid extradition. The Special Commission of Inquiry, established by the Betancur government after intense public pressure, released a June 1986 report which concluded that this was not the case.


title: Palace of Justice siege

text: Author Ana Carrigan, who quoted the June 1986 report in her book on the siege and originally dismissed any such links between the M-19 and the drug mafia, told "Cromos" magazine in late 2005 that she now believes that the mafia may have financially supported the M-19.


title: Palace of Justice siege

text: Pablo Escobar's son claimed that while his father did not come up with or plan the raid, he did pay M-19 a million dollars. Escobar said that he supported M-19 because he "believed in the ideals" of M-19 and "looked for ways to preserve and support them".


title: Palace of Justice siege

text: On the same day of the siege, the Supreme Court's docket apparently called for the beginning of pending deliberations on the constitutionality of the Colombia-United States extradition treaty. The M-19 was publicly opposed to extradition on nationalist grounds. Several of the magistrates had been previously threatened by drug lords in order to prevent any possibility of a positive decision on the treaty. One year after the siege, the treaty was declared unconstitutional.


title: Palace of Justice siege

text: Former Assistant to the Colombian Attorney General, National Deputy Comptroller, author and renowned Professor Jose Mauricio Gaona (son of murdered Supreme Court magistrate ) along with the former Minister of Justice and Ambassador of Colombia to the United Kingdom, Carlos Medellín Becerra (son of magistrate ), have consistently pushed for further and broader lines of investigations related not only to the presumed links between the M-19 and the Medellín Cartel drug lords, but also to any other possible links to the investigations performed by the Justices of members of the Armed Forces. Congressman Gustavo Petro, a former M-19 guerrilla, has denied these accusations and dismissed them as based upon the inconsistent testimonies of drug lords. Petro says that the surviving members of the M-19 do admit to their share of responsibility for the tragic events of the siege, on behalf of the entire organization, but deny any links to the drug trade.


title: Palace of Justice siege

text: Later investigations and commentators have considered both the M-19 and the military as responsible for the deaths of the justices and civilians inside the building. Some have blamed President Belisario Betancur for not taking the necessary actions or for failing to negotiate, and others have commented on the possibility of a sort of "de facto" "24-hour coup", during which the military was in control of the situation.


title: Palace of Justice siege

text: According to Ana Carrigan's 1993 book "The Palace of Justice: A Colombian Tragedy", Supreme Court Chief Justice Alfonso Reyes was apparently burned alive during the assault, as someone incinerated his body after pouring gasoline over it. The book also asserts that, after the siege was over, some twenty-eight bodies were dumped into a mass grave and apparently soaked with acid, in order to make identification difficult. Carrigan argued that the bodies of the victims of the Nevado del Ruiz volcano eruption, which buried the city of Armero and killed more than 20,000 people, were dumped into the same mass grave, making any further forensic investigations impractical.


title: Palace of Justice siege

text: Despite numerous investigations and lawsuits to date, impunity prevailed for most of the subsequent decades. Ana Carrigan asserted in her 1993 book that "Colombia has moved on... Colombia has forgotten the Palace of Justice siege", in much the same way that, in her opinion, Colombians have also forgotten or adopted a position of denial towards other tragic events, such as the 1928 Santa Marta Massacre. No definite responsibility has been fixed on the government or on the surviving members of the M-19 movement who were pardoned after they demobilized.


title: Palace of Justice siege

text: Eduardo Umaña, the first attorney representing some of the families of the people killed during the siege, was assassinated in 1998, and several members of those families had to flee to Europe because of death threats against them.


title: Palace of Justice siege

text: At least 11 people disappeared during the events of the siege, most of them cafeteria workers, the fate of ten of them unknown. It is likely that their remains may be among a number of unidentified and charred bodies, one of which was identified through DNA testing done by the National University of Colombia, leaving the fates of the other 10 still in question.


title: Palace of Justice siege

text: According to Ana Carrigan, Irma Franco, a law student and M-19 guerrilla, disappeared after she was captured. Carrigan states that Franco was seen in the custody of Colombian special forces by several hostages. She also states that the guerrilla left with several hostages and was never seen again. The Special Commission of Inquiry confirmed Franco's disappearance, and the judges requested that the investigation of her case be thoroughly pursued.


title: Palace of Justice siege

text: One week after the siege, M-19 released a communique to the press claiming that six leaders, including Franco, and "seven other fighters" had all been "disappeared and murdered" by the army. From the tapes of the military and police inter-communications it is known that army intelligence arrested at least seventeen people in the course of the two-day siege. None of the M-19 leaders, with the exception of Andrés Almarales, were ever identified in the city morgue.


title: Palace of Justice siege

text: The events surrounding the Palace of Justice siege received renewed media coverage in Colombia during the 20th anniversary of the tragedy. Among other outlets, the country's main daily "El Tiempo", the weekly "El Espectador", and the "Cromos" magazine published several articles, interviews and opinion pieces on the matter, including stories about the survivors, as well as the plight of the victims' relatives and those of the missing.


title: Palace of Justice siege

text: The Supreme Court created a Truth Commission in order to investigate the siege. The Commission officially began its work on November 3, 2005.


title: Palace of Justice siege

text: On 22 August 2006, Attorney General Mario Iguarán announced that former Colonel Edilberto Sánchez, former B-2 intelligence chief of the Army's Thirteenth Brigade, would be summoned for questioning and investigated for the crimes of kidnapping and forced disappearance. Public prosecutors are to reopen the case after examining video tape recordings and identifying cafeteria manager Carlos Augusto Rodríguez being taken outside of the Palace of Justice alive by a soldier, together with other former M-19 hostages.


title: Palace of Justice siege

text: Former Col. Sánchez was then detained. In May 2007, former Col. Sánchez has been questioned by prosecutors about his possible role in the disappearance of Irma Franco and at least two cafeteria workers, who would have left the Palace alive. Sánchez rejected the charges and proclaimed his innocence. He accepted that he could have received the order to cover the exit of some hostages from the Palace of Justice.


title: Palace of Justice siege

text: On 11 July 2008, Virginia Vallejo, the television anchorwoman who was romantically involved with Pablo Escobar from 1983 to 1987 and author of (2007) (Loving Pablo, Hating Escobar), was asked to testify in the reopened case of the siege of the Palace of Justice, in order to confirm events that she had described in her memoir, in the chapter "That Palace in Flames", in pages 230 to 266. In the Colombian Consulate in Miami, under oath, she described the relationship of the drug lord with the Sandinista Government of Nicaragua and the M-19; also, a meeting of Escobar with the rebel commander Ivan Marino Ospina, in which she had been present, two weeks before the latter was killed by the Army, on August 28, 1985. In her judicial declaration, Vallejo confirmed how, in mid-1986, Escobar had told her that he had paid one million dollars in cash to the rebels, and another million in arms and explosives to steal his files from the Palace of Justice, before the Supreme Court began studying the extradition of the leading members of the cocaine cartels to the United States. During her testimony, that lasted five hours, the journalist described also photographs of sixteen bodies that she had received anonymously in that year. According to her, Escobar identified the victims as the employees of the cafeteria of the Palace and two rebel women that had been detained by the Army after the siege, and had been tortured and disappeared on orders of colonel Edilberto Sánchez, director of B-2, Military Intelligence. Though her testimony was protected under gag, several excerpts appeared on 17 August 2008 in "El Tiempo", the newspaper of the Santos' family, including the vice president Francisco Santos, and defense minister Juan Manuel Santos. On radio stations, Vallejo accused the office of the Colombian Attorney General of filtering it to the media and adulterating the contents, to protect the military and the former presidential candidate Alberto Santofimio, Escobar's political ally. On 3 June 2010, Virginia Vallejo was granted political asylum in the United States of America.


title: Palace of Justice siege

text: In 2010, retired Colonel Alfonso Plazas Vega was sentenced to 30 years imprisonment for his alleged role in forced disappearances after the siege.


title: Palace of Justice siege

text: The President of Colombia, Álvaro Uribe, reacted by declaring that he was "sad and hurt" by the decision. He announced his intention of seeking changes to the way military are judged in Colombia and asked for prison sentences for those he called the "instigators" of the massacre. Uribe also had a meeting with the military command to find ways to protect them from "judiciary decisions that interfere with their work".


title: Palace of Justice siege

text: Nevertheless, Colombia's General Attorney has declared that crimes against humanity took place during the siege, which has allowed for the continued processing of another colonel and one general involved in the incident. María Stella Jara, the judge that handed the sentence to Colonel Plazas left the country after receiving multiple death threats to her and her son. She and her family had to live under heavy surveillance for the duration of the trial.


title: Palace of Justice siege

text: On 16 December 2015 Colonel Plazas Vega was declared innocent in a five to three vote by the Colombian Supreme Court and absolved of his previous 30-year prison sentence. The declaration was influenced by a revisiting of the case in the Supreme Court when the validity of testimonies of four witnesses came into question, along with absence of conclusive evidence to prove guilty in the charges brought again Plazas Vega.


title: Who Am I? (1998 film)

text: Who Am I? (, also known as Jackie Chan's Who Am I?) is a 1998 Hong Kong action comedy film directed by Benny Chan and Jackie Chan, who also starred in the lead role. The film was released in Hong Kong on 17 January 1998. It is also Chan's second film to be scripted and shot in English, the first one being "Mr. Nice Guy".


title: Who Am I? (1998 film)

text: Somewhere in the jungles of South Africa on Thanksgiving 1996, a multinational military unit named "Special Force Unit" ambushes a convoy and kidnaps several scientists working on a highly-volatile compound extracted from a recently discovered meteorite. Among the operatives is a Hong Kong national identified as "Jackie Chan". The CIA assigns Morgan to investigate the incident, unaware that he and newly retired General Sherman orchestrated the abduction for their personal profit. At the same time, the CIA assigns another operative in South Africa for a more covert operation.


title: Who Am I? (1998 film)

text: Jackie wakes up in a tribal village somewhere in the African veldt, still recovering from injuries sustained in an accident he cannot remember. When asked for his name by the natives, he does not remember who he is and repeatedly asks himself, "Who Am I?". He is referred to as "Who Am I?" by the natives, as they think it is his name. The tribesmen show him the remains of a crashed helicopter and graves of those who perished aboard. "Who Am I?" spends weeks recuperating from his wounds and learning about the tribe's culture. After spotting rally cars from several miles away, "Who Am I?" bids the village farewell and ventures on a journey back to civilization. He befriends Japanese rally co-driver Yuki after saving her brother from a snake bite and offering to help them finish the race. When they reach Johannesburg, "Who Am I?" meets Christine Stark, a journalist sent to interview him about his rally adventure.


title: Who Am I? (1998 film)

text: Morgan hears of "Who Am I?" and sends a hitman team to kill him. Morgan also pretends to be his ally, telling him to contact him if he is in danger. After escaping from the hitmen, Christine cracks a secret code written on a matchbook found on one of the dead operatives, which leads them to Rotterdam, in the Netherlands. "Who Am I?" and Christine bid Yuki farewell and head for Rotterdam to find more answers to his identity. In Rotterdam, "Who Am I?" discovers that Christine is actually an undercover CIA agent who tapped his calls. Not knowing whom to trust, he battles Sherman's hitmen and sneaks into the "Willemswerf" skyscraper alone, where he discovers the masterminds behind the kidnapping of the scientists.


title: Who Am I? (1998 film)

text: It is revealed that Morgan and General Sherman are about to sell the extraterrestrial compound to an influential arms dealer named Armano. While waiting for the online wire transfer to finish, the three men leave the conference room for a coffee break – giving "Who Am I?" time to sneak in and steal the disc containing the compound information. He also cancels the transaction and sends the money to a children's charity, which infuriates Armano. Sherman and Armano send several men after "Who Am I?" to get the disc back. While in the process of escaping, "Who Am I?" defeats several hitmen and is found by Morgan. Once he discovers Morgan's betrayal, "Who Am I?" tries to kill Morgan, but is interrupted by Morgan's hitmen, who also try to take back the disc. "Who Am I?" fights them off and recovers the disk, but Morgan flees. "Who Am I?" regroups with Christine, who calls for the execution of a "Plan B". Several CIA agents join the pursuit of Morgan, cornering him on the Erasmus Bridge in cooperation with the Royal Netherlands Marine Corps. Christine takes Morgan into custody and asks "Who Am I?" if he has the disc. He throws the disc off the bridge and tells Christine that he will return to Africa.


title: Who Am I? (1998 film)

text: "Who Am I?" was shot on locations in Namibia, South Africa, and Netherlands between February and March 1997. The film features several landmarks such as Sun City in South Africa, Erasmus Bridge in Rotterdam, the Beurstraverse (which was portrayed by the film makers as being in Johannesburg), the Cube houses and the Willemswerf building (which served as the headquarters of the villains and from the side of which, "Who Am I?" escaped by sliding to the ground). Dutch city Dordrecht was also used as a location on the Voorstraat, de Vleeshouwersstraat as well as the fountains by Hans Petri in front of the former Refaja hospital.


title: Who Am I? (1998 film)

text: The film also features an elaborate chase scene involving the Mitsubishi Lancer Evolution IV GSR and a pack of chasing BMW 3 series (E36), in which Jackie, Yuki, and Christine (in the Evolution) attempt to escape from their captors. Several memorable stunts in the Evolution IV were featured, including a spin parking manoeuvre, market chase, and flipping the car onto its side and roof. In the making-of documentary, the team outlined the numerous Lancer Evolutions that were used for the entire sequence due to the harsh physical challenges presented by the stunts. The use of the Evolution IV was consistent with the ongoing presence and sponsorship of Mitsubishi in Jackie Chan's films of that era.


title: Who Am I? (1998 film)

text: In Hong Kong, "Who Am I?" grossed HK$38,852,845 during its theatrical run. In China, it grossed at the box office. In Taiwan, it sold 155,211 tickets and grossed . In South Korea, film sold 193,293 tickets in Seoul City and 579,879 tickets nationwide, grossing . In Europe, the film sold 157,427 tickets in Germany, and 73,101 tickets in other European countries.


title: Who Am I? (1998 film)

text: On Rotten Tomatoes, the film has an approval rating of 67% based on 9 reviews, with an average rating of 6.2/10.