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both cars perform perfectly, they would cross the finish line dead even. If either car goes faster than its dial- in( called breaking out), it is disqualified regardless of who has the lower elapsed time; if both cars break out, the one who breaks out by the smallest amount wins. However, if a driver had jump- started( red light) or crossed a boundary line, both violations override any break out( except in some classes with an absolute break out rule such as Junior classes). The effect of the bracket racing rules is to place a premium on consistency of performance of the driver and car rather than on raw speed, in that victory goes to the driver able to precisely predict elapsed time, whether it is fast or slow. This in turn makes victory much less dependent on budget, and more dependent on skill, making it popular with casual weekend racers. The draugr or draug(, plural; modern, and Danish, Swedish, and) is an undead creature from the Scandinavian saga literature and folktale. Commentators extend the term" draugr" to the undead in medieval literature, even if it is never explicitly referred to as that in the text, and designated them rather as a(" barrow- dweller") or an, literally" again- walker"(). Overview. Draugar live in their graves or royal palaces, often guarding treasure buried with them in their burial mound. They are revenants, or animated corpses with a corporeal body, rather than ghosts which possess intangible spiritual bodies. Terminology. Old Norse"" is defined as" a ghost, spirit, esp. the dead inhabitant of a cairn". Often the" draugr" is regarded not so much as a ghost but a revenant, i. e., the reanimated of the deceased inside the burial mound( as in the example of Kárr inn gamli in" Grettis saga"). The" draugr" was referred to as" as barrow- wight" in the 1869 translation of" Grettis saga", long before J. R. R. Tolkien employed this term in his novels, though" barrow- wight" is actually a rendering of( literally the‘ howe- dweller’), otherwise translated as" barrow- dweller". Cognates and etymology. In Swedish," draug" is a modern loanword from West Norse, as the native Swedish form" drög" has acquired the meaning of" a pale, ineffectual, and slow- minded person that drags himself along". The word is hypothetically traced to Proto- Indo European stem"*"" phantom", from"*"" deceive"( see also Avestan" druj"). Broadened usage. Unlike Kárr inn gamli( Kar the Old) in" Grettis saga", who is specifically called a" draugr", Glámr the ghost in the same saga is never explicitly called a" draugr" in the text, though called a" troll" in it. Yet Glámr is still routinely referred to as a" draugr". Beings not specifically called, but actually only referred to as(‘ revenants’, pl. of) and(‘ haunting’) in these medieval sagas are still commonly discussed as a in various scholarly works, or the" draugar" and the haugbúar are lumped into one. A further caveat is that the application of the term" draugr" may not necessarily follow what the term might have meant in the strict sense during medieval times, | but rather follow a modern |
definition or notion of" draugr", specifically such ghostly beings( by whatever names they are called) that occur in Icelandic folktales categorized as" Draugasögur" in Jón Árnason' s collection, based on the classification groundwork laid by Konrad Maurer. Overall classification. The draugr is a" corporeal ghost" with a physical tangible body and not an" imago", and in tales it is often delivered a" second death" by destruction of the enlivened corpse. The draugr has also been conceived of as a type of" vampire" by folktale anthologist Andrew Lang in the late 1897, with the idea further pursued by more modern commentators. The focus here is not on blood- sucking, which is not attested for the" draugr", but rather, contagiousness or transmittable nature of vampirism, that is to say, how a vampire begets another by turning his or her attack victim into one of his own kind. Sometimes the chain of contagion becomes an outbreak, e. g., the case of Þórólfr bægifótr( Thorolf Lame- foot or Twist- Foot), and even called an" epidemic" regarding Þórgunna( Thorgunna). A more speculative case of vampirism is that of Glámr, who was asked to tend sheep for a haunted farmstead and was subsequently found dead with his neck and every bone in his body broken. It has been surmised by commentators that Glámr by" contamination" was turned into an undead(" draugr") by whatever being was haunting the farm. Physical traits. Draugar usually possessed superhuman strength, and was" generally hideous to look at", bearing a necrotic black color, and was associated with a" reek of decay" or more precisely inhabited haunts that often issued foul stench. The draugar were said to be either" hel- blár"(" death- blue") or" nár- fölr"(" corpse- pale"), to state it in shorthand. Glámr when found dead was described as"" blár sem Hel en digr sem naut"( black as hell and bloated to the size of a bull)". Þórólfr Lame- foot, when lying dormant, looked" uncorrupted" and also" was black as death[ i. e., bruised black and blue] and swollen to the size of an ox". The close similarity of these descriptions have been noted." Laxdæla saga" describes how bones were dug up belonging to a dead sorceress who had appeared in dreams, and they were" blue and evil looking". Þráinn( Thrain) the berserker of Valland" turned himself into a troll" in" Hrómundar saga Gripssonar" was a fiend(" dólgr") which was" black and huge.. roaring loudly and blowing fire", and moreover, possessed long scratching claws, and the claws stuck in the neck, prompting the hero Hrómundr to refer to the" dragur" as a sort of cat(). The long claw is a common trait of another revenant, Ásviðr( Aswitus) who came to life in the night and attacked his foster- brother Ásmundr( Asmundus) with the claws, scratching the face and tearing an ear. The mound where Kárr the Old was entombed reeked horribly. In" Harðar saga" Hörðr Grímkelsson’ s two underlings die even before entering Sóti the Viking' s mound, due to the" gust and stink()" wafting out of it. Magical abilities. Draugar are noted for | having numerous magical abilities( referred |
to as" trollskap") resembling those of living witches and wizards, such as shape- shifting, controlling the weather, and seeing into the future. Shape- shifting. The undead Víga- Hrappr Sumarliðason( Killer- Hrapp) of" Laxdaela saga", unlike the typical guardian of a treasure hoard, does not stay put in his burial place but roams around his farmstead of Hrappstaðir, menacing the living. Víga- Hrappr' s ghost, it has been suggested, was capable of transforming into the seal with human- like eyes which appeared before Þorsteinn svarti/ surt( Thorsteinn the Black) sailing by ship, and was responsible for the sinking of the ship to prevent the family from reaching Hrappstaðir. The ability to shape- shift has been ascribed to Icelandic ghosts generally, particularly into the shape of a seal. A draugr in Icelandic folktales collected in the modern age can also change into a great flayed bull, a grey horse with a broken back but no ears or tail, and a cat that would sit upon a sleeper' s chest and grow steadily heavier until their victim suffocated. Other magical abilities. Draugar have the ability to enter into the dreams of the living, and they will frequently leave a gift behind so that" the living person may be assured of the tangible nature of the visit". Draugar also have the ability to curse a victim, as shown in the Grettis saga, where Grettir is cursed to be unable to become any stronger. Draugar also brought disease to a village and could create temporary darkness in daylight hours. They preferred to be active during the night, although they did not appear to be vulnerable to sunlight like some other revenants. Draugr can also kill people with bad luck. A draugr' s presence might be shown by a great light that glowed from the mound like foxfire. This fire would form a barrier between the land of the living and the land of the dead. The undead Víga- Hrappr exhibited the ability to sink into the ground to escape from Óláfr Hǫskuldsson the Peacock. Some draugar are immune to weapons, and only a hero has the strength and courage needed to stand up to so formidable an opponent. In legends, the hero would often have to wrestle the draugr back to his grave, thereby defeating him, since weapons would do no good. A good example of this is found in" Hrómundar saga Gripssonar". Iron could injure a draugr, as is the case with many supernatural creatures, although it would not be sufficient to stop it. Sometimes the hero is required to dispose of the body in unconventional ways. The preferred method is to cut off the draugr' s head, burn the body, and dump the ashes in the sea— the emphasis being on making absolutely sure that the draugr was dead and gone. Behaviour and character. Any mean, nasty, or greedy person can become a draugr. As Ármann Jakobsson notes," most medieval Icelandic ghosts are evil or marginal people. If not dissatisfied or evil, they are unpopular". Greed. The draugr' s motivation was primarily jealousy and greed. | Greed causes it to viciously |
attack any would- be grave robbers, but the draugr also expresses an innate jealousy of the living stemming from a longing for the things of life which it once had. They also exhibit an immense and nearly insatiable appetite, as shown in the encounter of Aran and Asmund, sword brothers who made an oath that, if one should die, the other would sit vigil with him for three days inside the burial mound. When Aran died, Asmund brought his own possessions into the barrow— banners, armor, hawk, hound, and horse— then set himself to wait the three days: Bloodthirst. The draugr' s victims were not limited to trespassers in its home. The roaming undead devastated livestock by running the animals to death either by riding them or pursuing them in some hideous, half- flayed form. Shepherds' duties kept them outdoors at night, and they were particular targets for the hunger and hatred of the undead: Animals feeding near the grave of a draugr might be driven mad by the creature' s influence. They may also die from being driven mad. Thorolf, for example, caused birds to drop dead when they flew over his bowl barrow. Sitting posture and evil eye. The main indication that a deceased person will become a draugr is that the corpse is not in a horizontal position but is found standing upright( Víga- Hrappr), or in a sitting position( Þórólfr), indicating that the dead might return. Ármann Jakobsson suggests further that breaking the draugr' s posture is a necessary or helpful step in destroying the" draugr", but this is fraught with the risk of being inflicted with the evil eye, whether this is explictly told in the case of Grettir who receives the curse from Glámr, or only implied in the case of Þórólfr, whose son warns the others to beware while they unbend Þórólfr' s seated posture. Annihilating. The revenant" draugr" needing to be decapitated in order to incapacitate them from further hauntings is a common theme in the family sagas. Means of prevention. Traditionally, a pair of open iron scissors was placed on the chest of the recently deceased, and straws or twigs might be hidden among their clothes. The big toes were tied together or needles were driven through the soles of the feet in order to keep the dead from being able to walk. Tradition also held that the coffin should be lifted and lowered in three different directions as it was carried from the house to confuse a possible draugr' s sense of direction. The most effective means of preventing the return of the dead was believed to be a corpse door, a special door through which the corpse was carried feet- first with people surrounding it so that the corpse couldn' t see where it was going. The door was then bricked up to prevent a return. It is speculated that this belief began in Denmark and spread throughout the Norse culture, founded on the idea that the dead could only leave through the way they entered. In" Eyrbyggja saga", draugar are | driven off by holding a" |
door- doom". One by one, they are summoned to the door- doom and given judgment and forced out of the home by this legal method. The home was then purified with holy water to ensure that they never came back. Similar beings. A variation of the draugr is the" haugbui"( from Old Norse" haugr"'" howe, barrow, tumulus") which was a mound- dweller, the dead body living on within its tomb. The notable difference between the two was that the haugbui is unable to leave its grave site and only attacks those who trespass upon their territory. The haugbui was rarely found far from its burial place and is a type of undead commonly found in Norse sagas. The creature is said to either swim alongside boats or sail around them in a partially submerged vessel, always on their own. In some accounts, witnesses portray them as shapeshifters who take on the appearance of seaweed or moss- covered stones on the shoreline. Folklore. Icelandic Sagas. One of the best- known draugar is Glámr, who is defeated by the hero in" Grettis saga". After Glámr dies on Christmas Eve," people became aware that Glámr was not resting in peace. He wrought such havoc that some people fainted at the sight of him, while others went out of their minds". After a battle, Grettir eventually gets Glámr on his back. Just before Grettir kills him, Glámr curses Grettir because" Glámr was endowed with more evil force than most other ghosts", and thus he was able to speak and leave Grettir with his curse after his death. A somewhat ambivalent, alternative view of the draugr is presented by the example of Gunnar Hámundarson in" Njáls saga":" It seemed as though the howe was agape, and that Gunnar had turned within the howe to look upwards at the moon. They thought that they saw four lights within the howe, but not a shadow to be seen. Then they saw that Gunnar was merry, with a joyful face." In the" Eyrbyggja saga", a shepherd is assaulted by a blue- black draugr. The shepherd' s neck is broken during the ensuing scuffle. The shepherd rises the next night as a draugr. Recent. In more recent Scandinavian folklore, the draug( the modern spelling used in Denmark, Norway, and Sweden) is often identified with the spirits of mariners drowned at sea. The creature is said to possess a distinctly human form, with the exception that its head is composed entirely of seaweed. In other tellings, the draug is described as being a headless fisherman, dressed in oilskin and sailing in half a boat( the Norwegian municipality of Bø, Nordland has the half- boat in its coat- of- arms). This trait is common in the northernmost part of Norway, where life and culture was based on fishing more than anywhere else. The reason for this may be that the fishermen often drowned in great numbers, and the stories of restless dead coming in from sea were more common in the north than any other region of the country. A recorded legend from | Trøndelag tells how a cadaver |
lying on a beach became the object of a quarrel between the two types of draug( headless and seaweed- headed). A similar source even tells of a third type, the" gleip", known to hitch themselves to sailors walking ashore and make them slip on the wet rocks. But, though the draug usually presages death, there is an amusing account in Northern Norway of a northerner who managed to outwit him: Use in popular culture. The modern and popular connection between the draug and the sea can be traced back to authors like Jonas Lie and Regine Nordmann, whose works include several books of fairy tales, as well as the drawings of Theodor Kittelsen, who spent some years living in Svolvær. Up north, the tradition of sea- draugs is especially vivid. Arne Garborg describes land- draugs coming fresh from the graveyards, and the term" draug" is even used of vampires. The notion of draugs who live in the mountains is present in the poetic works of Henrik Ibsen(" Peer Gynt"), and Aasmund Olavsson Vinje. The Nynorsk translation of" The Lord of the Rings" used the term for both Nazgûl and the dead men of Dunharrow. Tolkien' s Barrow- Wights bear obvious similarity to, and were inspired by the haugbui. In the video game"", draugr are the undead skeletal remains of fallen warriors that inhabit the ancient burial sites of a Nordic- inspired race of man. These draugr behave more like haugbui, than traditional draugr. Draugr are a common enemy, the first encountered by the player, in the 2018 video game" God of War", with a variety of different powers and abilities. In 2019, a spaceship named" Draugur" was added to the game Eve Online, as the command destroyer of the Triglavian faction. Draugr appear as an enemies in the 2021 early access game" Valheim", where they take the more recent, seaweed version of the Draug. Season 2 Episode 2 of Hilda, entitled" The Draugen," involved draugen as the ghosts of sailors who died at sea. While their form was ghostly, the captain was able to wear a coat, and had a shock of seaweed for hair.TheexoplanetPSRB1257+ 12 A has been named" Draugr". The word day has a number of meanings, depending on the context it is used such as of astronomy, physics, and various calendar systems. As a term in physics and astronomy it is approximately the period during which the Earth completes one rotation around its axis, which takes about 24 hours. A solar day is the length of time which elapses between the Sun reaching its highest point in the sky two consecutive times. Days on other planets are defined similarly and vary in length due to differing rotation periods, that of Mars being slightly longer and sometimes called a sol. The unit of measurement" day"( symbol d) is defined as 86, 400 SI seconds. The second is designated the SI base unit of time. Previously, it was defined in terms of the orbital motion of the Earth in the year 1900, but since 1967 the second and so the day | are defined by atomic electron |
transition. A civil day is usually 24 hours, plus or minus a possible leap second in Coordinated Universal Time( UTC), and occasionally plus or minus an hour in those locations that change from or to daylight saving time. Day can be defined as each of the twenty- four- hour periods, reckoned from one midnight to the next, into which a week, month, or year is divided, and corresponding to a rotation of the earth on its axis. However, its use depends on its context; for example, when people say' day and night',' day' will have a different meaning: the interval of light between two successive nights, the time between sunrise and sunset; the time of light between one night and the next. For clarity when meaning' day' in that sense, the word" daytime" may be used instead, though context and phrasing often makes the meaning clear. The word" day" may also refer to a day of the week or to a calendar date, as in answer to the question," On which day?" The biologically determined living patterns( circadian rhythms) of humans and many other species relate to Earth' s solar day and the day- night cycle. Introduction. Apparent and mean solar day. Several definitions of this universal human concept are used according to context, need and convenience. Besides the day of 24 hours( 86, 400 seconds), the word" day" is used for several different spans of time based on the rotation of the Earth around its axis. An important one is the solar day, defined as the time it takes for the Sun to return to its culmination point( its highest point in the sky). Because celestial orbits are not perfectly circular, and thus objects travel at different speeds at various positions in their orbit, a solar day is not the same length of time throughout the orbital year. Because the Earth moves along an eccentric orbit around the Sun while the Earth spins on an inclined axis, this period can be up to 7. 9 seconds more than( or less than) 24 hours. In recent decades, the average length of a solar day on Earth has been about 86, 400. 002 seconds( 24. 000 000 6 hours) and there are currently about 365. 2421875 solar days in one mean tropical year. Ancient custom has a new day start at either the rising or setting of the Sun on the local horizon( Italian reckoning, for example, being 24 hours from sunset, oldstyle). The exact moment of, and the interval between, two sunrises or sunsets depends on the geographical position( longitude and latitude, as well as altitude), and the time of year( as indicated by ancient hemispherical sundials). A more constant day can be defined by the Sun passing through the local meridian, which happens at local noon( upper culmination) or midnight( lower culmination). The exact moment is dependent on the geographical longitude, and to a lesser extent on the time of the year. The length of such a day is nearly constant( 24 hours± 30 seconds). This is the time as indicated | by modern sundials. A further |
improvement defines a fictitious mean Sun that moves with constant speed along the celestial equator; the speed is the same as the average speed of the real Sun, but this removes the variation over a year as the Earth moves along its orbit around the Sun( due to both its velocity and its axial tilt). Stellar day. A" day", understood as the span of time it takes for the Earth to make one entire rotation with respect to the celestial background or a distant star( assumed to be fixed), is called a" stellar day". This period of rotation is about 4 minutes less than 24 hours( 23 hours 56 minutes and 4. 09 seconds) and there are about 366. 2422 stellar days in one mean tropical year( one stellar day more than the number of solar days). Other planets and moons have stellar and solar days of different lengths from Earth' s. Besides a stellar day on Earth, other bodies in the Solar System have day times, the durations of these being: Daytime vs. nightime. A day, in the sense of daytime that is distinguished from night time, is commonly defined as the period during which sunlight directly reaches the ground, assuming that there are no local obstacles. The length of daytime averages slightly more than half of the 24- hour day. Two effects make daytime on average longer than nights. The Sun is not a point, but has an apparent size of about 32 minutes of arc. Additionally, the atmosphere refracts sunlight in such a way that some of it reaches the ground even when the Sun is below the horizon by about 34 minutes of arc. So the first light reaches the ground when the centre of the Sun is still below the horizon by about 50 minutes of arc. Thus, daytime is on average around 7 minutes longer than 12 hours. Etymology. The term comes from the Old English" dæg", with its cognates such as" dagur" in Icelandic," Tag" in German, and" dag" in Norwegian, Danish, Swedish and Dutch- all stemming from a Proto- Germanic root"* dagaz".," day"isthe205th most common word in US English,andthe210th most common in UK English. International System of Units( SI). A day, symbol d, defined as 86, 400 seconds, is not an SI unit, but is accepted for use with SI. The second is the base unit of time in SI units. In 1967– 68,duringthe13th CGPM( Resolution 1), the International Bureau of Weights and Measures( BIPM) redefined a second as... the duration of 9 192 631 770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of the caesium 133 atom. This makes the SI- based day last exactly 794, 243, 384, 928, 000 of those periods. There are 365. 25 days in a Julian year. Leap seconds. Mainly due to tidal effects, the Earth' s rotational period is not constant, resulting in minor variations for both solar days and stellar" days". The Earth' s day has increased in length over time due to tides raised by the | Moon which slow Earth' s |
rotation. Because of the way the second is defined, the mean length of a day is now about 86, 400. 002 seconds, and is increasing by about 1. 7 milliseconds per century( an average over the last 2, 700 years). The length of a day circa 620 million years ago has been estimated from rhythmites( alternating layers in sandstone) as having been about 21. 9 hours. In order to keep the civil day aligned with the apparent movement of the Sun, a day according to Coordinated Universal Time( UTC) can include a negative or positive leap second. Therefore, although typically 86, 400 SI seconds in duration, a civil day can be either 86, 401 or 86, 399 SI seconds long on such a day. Leap seconds are announced in advance by the International Earth Rotation and Reference Systems Service( IERS), which measures the Earth' s rotation and determines whether a leap second is necessary. Civil day. For civil purposes, a common clock time is typically defined for an entire region based on the local mean solar time at a central meridian. Such" time zones"begantobeadoptedaboutthemiddleofthe19th century when railroads with regularly occurring schedules came into use, with most major countries having adopted them by 1929. As of 2015, throughout the world, 40 such zones are now in use: the central zone, from which all others are defined as offsets, is known as, which uses Coordinated Universal Time( UTC). The most common convention starts the civil day at midnight: this is near the time of the lower culmination of the Sun on the central meridian of the time zone. Such a day may be referred to as a calendar day. A day is commonly divided into 24 hours of 60 minutes, with each minute composed of 60 seconds. Decimal and metric time.Inthe19th century, an idea circulated to make a decimal fraction( or) of an astronomical day the base unit of time. This was an afterglow of the short- lived movement toward a decimalisation of timekeeping and the calendar, which had been given up already due to its difficulty in transitioning from traditional, more familiar units. The most successful alternative is the" centiday", equal to 14. 4 minutes( 864 seconds), being not only a shorter multiple of an hour( 0. 24 vs 2. 4) but also closer to the SI multiple" kilosecond"( 1, 000 seconds) and equal to the traditional Chinese unit," kè". Colloquial. The word refers to various similarly defined ideas, such as: Boundaries. For most diurnal animals, the day naturally begins at dawn and ends at sunset. Humans, with their cultural norms and scientific knowledge, have employed several different conceptions of the day' s boundaries. In the Hebrew Bible, Genesis 1: 5 defines a day in terms of" evening" and" morning" before recounting the creation of a sun to illuminate it:" And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day." Common convention among the ancient Romans, ancient Chinese and in modern times is for the civil day to begin at midnight, | i. e. 00: 00, and |
to last a full 24 hours until 24: 00( i. e. 00: 00 of the next day). In ancient Egypt the day was reckoned from sunrise to sunrise. The Jewish day begins at either sunset or nightfall( when three second- magnitude stars appear). Medieval Europe also followed this tradition, known as Florentine reckoning: in this system, a reference like" two hours into the day" meant" two hours after sunset" and thus times during the evening need to be shifted back one calendar day in modern reckoning. Days such as Christmas Eve, Halloween, and the Eve of Saint Agnes are remnants of the older pattern when holidays began during the prior evening. Prior to 1926, Turkey had two time systems: Turkish( counting the hours from sunset) and French( counting the hours from midnight). Validity of tickets, passes, etc., for a day or a number of days may end at midnight, or closing time, whichever occurs earlier. However, if a service( e. g., public transport) operates from for example, 06: 00 to 01: 00 the next day( which may be noted as 25: 00), the last hour may well count as being part of the previous day. For services depending on the day(" closed on Sundays"," does not run on Fridays", and so on) there is a risk of ambiguity. For example, a day ticket on the Nederlandse Spoorwegen( Dutch Railways) is valid for 28 hours, from 00: 00 to 28: 00( that is, 4: 00 the next day); the validity of a pass on Transport for London( TfL) services runs until the end of the" transport day"– that is to say, until 4: 30 am on the day after the" expires" date stamped on the pass. Midnight sun. In places which experience the midnight sun( polar day), daytime may extend beyond one 24- hour period and could even extend to months. In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spans formal techniques and practical considerations including data modeling, efficient data representation and storage, query languages, security and privacy of sensitive data, and distributed computing issues including supporting concurrent access and fault tolerance. A database management system( DBMS) is the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS software additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a database system. Often the term" database" is also used loosely to refer to any of the DBMS, the database system or an application associated with the database. Computer scientists may classify database management systems according to the database models that they support. Relational databases became dominantinthe1980s. These model data as rows and columns in a series of tables, and the vast majority use SQL for writing and querying data. In the2000s, non- relational databases became popular, | collectively referred to as NoSQL |
because they use different query languages. Terminology and overview. Formally, a" database" refers to a set of related data and the way it is organized. Access to this data is usually provided by a" database management system"( DBMS) consisting of an integrated set of computer software that allows users to interact with one or more databases and provides access to all of the data contained in the database( although restrictions may exist that limit access to particular data). The DBMS provides various functions that allow entry, storage and retrieval of large quantities of information and provides ways to manage how that information is organized. Because of the close relationship between them, the term" database" is often used casually to refer to both a database and the DBMS used to manipulate it. Outside the world of professional information technology, the term" database" is often used to refer to any collection of related data( such as a spreadsheet or a card index) as size and usage requirements typically necessitate use of a database management system. Existing DBMSs provide various functions that allow management of a database and its data which can be classified into four main functional groups: Both a database and its DBMS conform to the principles of a particular database model." Database system" refers collectively to the database model, database management system, and database. Physically, database servers are dedicated computers that hold the actual databases and run only the DBMS and related software. Database servers are usually multiprocessor computers, with generous memory and RAID disk arrays used for stable storage. Hardware database accelerators, connected to one or more servers via a high- speed channel, are also used in large volume transaction processing environments. DBMSs are found at the heart of most database applications. DBMSs may be built around a custom multitasking kernel with built- in networking support, but modern DBMSs typically rely on a standard operating system to provide these functions. Since DBMSs comprise a significant market, computer and storage vendors often take into account DBMS requirements in their own development plans. Databases and DBMSs can be categorized according to the database model( s) that they support( such as relational or XML), the type( s) of computer they run on( from a server cluster to a mobile phone), the query language( s) used to access the database( such as SQL or XQuery), and their internal engineering, which affects performance, scalability, resilience, and security. History. The sizes, capabilities, and performance of databases and their respective DBMSs have grown in orders of magnitude. These performance increases were enabled by the technology progress in the areas of processors, computer memory, computer storage, and computer networks. The concept of a database was made possible by the emergence of direct access storage media such as magnetic disks, which became widely available inthemid1960s; earlier systems relied on sequential storage of data on magnetic tape. The subsequent development of database technology can be divided into three eras based on data model or structure: navigational, SQL/ relational, and post- relational. The two main early navigational data models were the hierarchical | model and the CODASYL model( |
network model). These were characterized by the use of pointers( often physical disk addresses) to follow relationships from one record to another. The relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links. The relational model employs sets of ledger- style tables, each used for a different type of entity. Only in the mid-1980s did computing hardware become powerful enough to allow the wide deployment of relational systems( DBMSs plus applications).Bytheearly1990s, however, relational systems dominated in all large- scale data processing applications, and they remain dominant:IBMDB2, Oracle, MySQL, and Microsoft SQL Server are the most searched DBMS. The dominant database language, standardised SQL for the relational model, has influenced database languages for other data models.Objectdatabasesweredevelopedinthe1980s to overcome the inconvenience of object– relational impedance mismatch, which led to the coining of the term" post- relational" and also the development of hybrid object– relational databases. The next generation of post-relationaldatabasesinthelate2000s became known as NoSQL databases, introducing fast key– value stores and document- oriented databases. A competing" next generation" known as NewSQL databases attempted new implementations that retained the relational/ SQL model while aiming to match the high performance of NoSQL compared to commercially available relational DBMSs.1960s, navigational DBMS. The introduction of the term" database" coincided with the availability of direct- access storage( disks and drums) from the mid-1960s onwards. The term represented a contrast with the tape- based systems of the past, allowing shared interactive use rather than daily batch processing. The Oxford English Dictionary cites a 1962 report by the System Development Corporation of California as the first to use the term" data- base" in a specific technical sense. As computers grew in speed and capability, a number of general- purpose database systems emerged; by the mid-1960s a number of such systems had come into commercial use. Interest in a standard began to grow, and Charles Bachman, author of one such product, the Integrated Data Store( IDS), founded the Database Task Group within CODASYL, the group responsible for the creation and standardization of COBOL. In 1971, the Database Task Group delivered their standard, which generally became known as the" CODASYL approach", and soon a number of commercial products based on this approach entered the market. The CODASYL approach offered applications the ability to navigate around a linked data set which was formed into a large network. Applications could find records by one of three methods: Later systems added B- trees to provide alternate access paths. Many CODASYL databases also added a declarative query language for end users( as distinct from the navigational API). However CODASYL databases were complex and required significant training and effort to produce useful applications. IBM also had their own DBMS in 1966, known as Information Management System( IMS). IMS was a development of software written for the Apollo program on the System/ 360. IMS was generally similar in concept to CODASYL, but used a strict hierarchy for its model of data navigation instead of CODASYL' s network model. Both concepts | later became known as navigational |
databases due to the way data was accessed: the term was popularized by Bachman' s 1973 Turing Award presentation" The Programmer as Navigator". IMS is classified by IBM as a hierarchical database. IDMS and Cincom Systems' TOTAL database are classified as network databases. IMS remains in use.1970s, relational DBMS. Edgar F. Codd worked at IBM in San Jose, California, in one of their offshoot offices that was primarily involved in the development of hard disk systems. He was unhappy with the navigational model of the CODASYL approach, notably the lack of a" search" facility. In 1970, he wrote a number of papers that outlined a new approach to database construction that eventually culminated in the groundbreaking" A Relational Model of Data for Large Shared Data Banks". In this paper, he described a new system for storing and working with large databases. Instead of records being stored in some sort of linked list of free- form records as in CODASYL, Codd' s idea was to organize the data as a number of" tables", each table being used for a different type of entity. Each table would contain a fixed number of columns containing the attributes of the entity. One or more columns of each table were designated as a primary key by which the rows of the table could be uniquely identified; cross- references between tables always used these primary keys, rather than disk addresses, and queries would join tables based on these key relationships, using a set of operations based on the mathematical system of relational calculus( from which the model takes its name). Splitting the data into a set of normalized tables( or" relations") aimed to ensure that each" fact" was only stored once, thus simplifying update operations. Virtual tables called" views" could present the data in different ways for different users, but views could not be directly updated. Codd used mathematical terms to define the model: relations, tuples, and domains rather than tables, rows, and columns. The terminology that is now familiar came from early implementations. Codd would later criticize the tendency for practical implementations to depart from the mathematical foundations on which the model was based. The use of primary keys( user- oriented identifiers) to represent cross- table relationships, rather than disk addresses, had two primary motivations. From an engineering perspective, it enabled tables to be relocated and resized without expensive database reorganization. But Codd was more interested in the difference in semantics: the use of explicit identifiers made it easier to define update operations with clean mathematical definitions, and it also enabled query operations to be defined in terms of the established discipline of first- order predicate calculus; because these operations have clean mathematical properties, it becomes possible to rewrite queries in provably correct ways, which is the basis of query optimization. There is no loss of expressiveness compared with the hierarchic or network models, though the connections between tables are no longer so explicit. In the hierarchic and network models, records were allowed to have a complex internal structure. For example, the salary history of an employee | might be represented as a" |
repeating group" within the employee record. In the relational model, the process of normalization led to such internal structures being replaced by data held in multiple tables, connected only by logical keys. For instance, a common use of a database system is to track information about users, their name, login information, various addresses and phone numbers. In the navigational approach, all of this data would be placed in a single variable- length record. In the relational approach, the data would be" normalized" into a user table, an address table and a phone number table( for instance). Records would be created in these optional tables only if the address or phone numbers were actually provided. As well as identifying rows/ records using logical identifiers rather than disk addresses, Codd changed the way in which applications assembled data from multiple records. Rather than requiring applications to gather data one record at a time by navigating the links, they would use a declarative query language that expressed what data was required, rather than the access path by which it should be found. Finding an efficient access path to the data became the responsibility of the database management system, rather than the application programmer. This process, called query optimization, depended on the fact that queries were expressed in terms of mathematical logic. Codd' s paper was picked up by two people at Berkeley, Eugene Wong and Michael Stonebraker. They started a project known as INGRES using funding that had already been allocated for a geographical database project and student programmers to produce code. Beginning in 1973, INGRES delivered its first test products which were generally ready for widespread use in 1979. INGRES was similar to System R in a number of ways, including the use of a" language" for data access, known as QUEL. Over time, INGRES moved to the emerging SQL standard. IBM itself did one test implementation of the relational model, PRTV, and a production one, Business System 12, both now discontinued. Honeywell wrote MRDS for Multics, and now there are two new implementations: Alphora Dataphor and Rel. Most other DBMS implementations usually called" relational" are actually SQL DBMSs. In 1970, the University of Michigan began development of the MICRO Information Management System based on D. L. Childs' Set- Theoretic Data model. MICRO was used to manage very large data sets by the US Department of Labor, the U. S. Environmental Protection Agency, and researchers from the University of Alberta, the University of Michigan, and Wayne State University. It ran on IBM mainframe computers using the Michigan Terminal System. The system remained in production until 1998. Integrated approach.Inthe1970sand1980s, attempts were made to build database systems with integrated hardware and software. The underlying philosophy was that such integration would provide higher performance at a lower cost. Examples were IBM System/ 38, the early offering of Teradata, and the Britton Lee, Inc. database machine. Another approach to hardware support for database management was ICL' s CAFS accelerator, a hardware disk controller with programmable search capabilities. In the long term, these efforts were generally unsuccessful because specialized | database machines could not keep |
pace with the rapid development and progress of general- purpose computers. Thus most database systems nowadays are software systems running on general- purpose hardware, using general- purpose computer data storage. However, this idea is still pursued for certain applications by some companies like Netezza and Oracle( Exadata).Late1970s, SQL DBMS. IBM started working on a prototype system loosely based on Codd' s concepts as" System R"intheearly1970s. The first version was ready in 1974/ 5, and work then started on multi- table systems in which the data could be split so that all of the data for a record( some of which is optional) did not have to be stored in a single large" chunk". Subsequent multi- user versions were tested by customers in 1978 and 1979, by which time a standardized query language– SQL– had been added. Codd' s ideas were establishing themselves as both workable and superior to CODASYL, pushing IBM to develop a true production version of System R, known as" SQL/ DS", and, later," Database 2"(DB2). Larry Ellison' s Oracle Database( or more simply, Oracle) started from a different chain, based on IBM' s papers on System R.ThoughOracleV1 implementations were completed in 1978, it wasn' t until Oracle Version 2 when Ellison beat IBM to market in 1979. Stonebraker went on to apply the lessons from INGRES to develop a new database, Postgres, which is now known as PostgreSQL. PostgreSQL is often used for global mission- critical applications( the. org and. info domain name registries use it as their primary data store, as do many large companies and financial institutions). In Sweden, Codd' s paper was also read and Mimer SQL was developed from the mid-1970s at Uppsala University. In 1984, this project was consolidated into an independent enterprise. Another data model, the entity– relationship model, emerged in 1976 and gained popularity for database design as it emphasized a more familiar description than the earlier relational model. Later on, entity– relationship constructs were retrofitted as a data modeling construct for the relational model, and the difference between the two have become irrelevant.1980s, on the desktop.The1980s ushered in the age of desktop computing. The new computers empowered their users with spreadsheets like Lotus 1- 2- 3 and database software like dBASE. The dBASE product was lightweight and easy for any computer user to understand out of the box. C. Wayne Ratliff, the creator of dBASE, stated:" dBASE was different from programs like BASIC, C, FORTRAN, and COBOL in that a lot of the dirty work had already been done. The data manipulation is done by dBASE instead of by the user, so the user can concentrate on what he is doing, rather than having to mess with the dirty details of opening, reading, and closing files, and managing space allocation." dBASE was one of the top sellingsoftwaretitlesinthe1980sandearly1990s.1990s, object- oriented.The1990s, along with a rise in object- oriented programming, saw a growth in how data in various databases were handled. Programmers and designers began to treat the data in their databases as objects. That is to say that if a person' s data | were in a database, that |
person' s attributes, such as their address, phone number, and age, were now considered to belong to that person instead of being extraneous data. This allows for relations between data to be relations to objects and their attributes and not to individual fields. The term" object– relational impedance mismatch" described the inconvenience of translating between programmed objects and database tables. Object databases and object– relational databases attempt to solve this problem by providing an object- oriented language( sometimes as extensions to SQL) that programmers can use as alternative to purely relational SQL. On the programming side, libraries known as object– relational mappings( ORMs) attempt to solve the same problem.2000s, NoSQL and NewSQL. XML databases are a type of structured document- oriented database that allows querying based on XML document attributes. XML databases are mostly used in applications where the data is conveniently viewed as a collection of documents, with a structure that can vary from the very flexible to the highly rigid: examples include scientific articles, patents, tax filings, and personnel records. NoSQL databases are often very fast, do not require fixed table schemas, avoid join operations by storing denormalized data, and are designed to scale horizontally. In recent years, there has been a strong demand for massively distributed databases with high partition tolerance, but according to the CAP theorem it is impossible for a distributed system to simultaneously provide consistency, availability, and partition tolerance guarantees. A distributed system can satisfy any two of these guarantees at the same time, but not all three. For that reason, many NoSQL databases are using what is called eventual consistency to provide both availability and partition tolerance guarantees with a reduced level of data consistency. NewSQL is a class of modern relational databases that aims to provide the same scalable performance of NoSQL systems for online transaction processing( read- write) workloads while still using SQL and maintaining the ACID guarantees of a traditional database system. Use cases. Databases are used to support internal operations of organizations and to underpin online interactions with customers and suppliers( see Enterprise software). Databases are used to hold administrative information and more specialized data, such as engineering data or economic models. Examples include computerized library systems, flight reservation systems, computerized parts inventory systems, and many content management systems that store websites as collections of webpages in a database. Classification. One way to classify databases involves the type of their contents, for example: bibliographic, document- text, statistical, or multimedia objects. Another way is by their application area, for example: accounting, music compositions, movies, banking, manufacturing, or insurance. A third way is by some technical aspect, such as the database structure or interface type. This section lists a few of the adjectives used to characterize different kinds of databases. Database management system. Connolly and Begg define database management system( DBMS) as a" software system that enables users to define, create, maintain and control access to the database". Examples of DBMS' s include MySQL, PostgreSQL, Microsoft SQL Server, Oracle Database, and Microsoft Access. The DBMS acronym is sometimes extended to indicate the underlying | database model, with RDBMS for |
the relational, OODBMS for the object( oriented) and ORDBMS for the object– relational model. Other extensions can indicate some other characteristic, such as DDBMS for a distributed database management systems. The functionality provided by a DBMS can vary enormously. The core functionality is the storage, retrieval and update of data. Codd proposed the following functions and services a fully- fledged general purpose DBMS should provide: It is also generally to be expected the DBMS will provide a set of utilities for such purposes as may be necessary to administer the database effectively, including import, export, monitoring, defragmentation and analysis utilities. The core part of the DBMS interacting between the database and the application interface sometimes referred to as the database engine. Often DBMSs will have configuration parameters that can be statically and dynamically tuned, for example the maximum amount of main memory on a server the database can use. The trend is to minimize the amount of manual configuration, and for cases such as embedded databases the need to target zero- administration is paramount. The large major enterprise DBMSs have tended to increase in size and functionality and can have involved thousands of human years of development effort through their lifetime. Early multi- user DBMS typically only allowed for the application to reside on the same computer with access via terminals or terminal emulation software. The client– server architecture was a development where the application resided on a client desktop and the database on a server allowing the processing to be distributed. This evolved into a multitier architecture incorporating application servers and web servers with the end user interface via a web browser with the database only directly connected to the adjacent tier. A general- purpose DBMS will provide public application programming interfaces( API) and optionally a processor for database languages such as SQL to allow applications to be written to interact with the database. A special purpose DBMS may use a private API and be specifically customized and linked to a single application. For example, an email system performing many of the functions of a general- purpose DBMS such as message insertion, message deletion, attachment handling, blocklist lookup, associating messages an email address and so forth however these functions are limited to what is required to handle email. Application. External interaction with the database will be via an application program that interfaces with the DBMS. This can range from a database tool that allows users to execute SQL queries textually or graphically, to a web site that happens to use a database to store and search information. Application program interface. A programmer will code interactions to the database( sometimes referred to as a datasource) via an application program interface( API) or via a database language. The particular API or language chosen will need to be supported by DBMS, possible indirectly via a preprocessor or a bridging API. Some API' s aim to be database independent, ODBC being a commonly known example. Other common API' s include JDBC and ADO. NET. Database languages. Database languages are special- purpose languages, which allow one | or more of the following |
tasks, sometimes distinguished as sublanguages: Database languages are specific to a particular data model. Notable examples include: A database language may also incorporate features like: Storage. Database storage is the container of the physical materialization of a database. It comprises the" internal"( physical)" level" in the database architecture. It also contains all the information needed( e. g., metadata," data about the data", and internal data structures) to reconstruct the" conceptual level" and" external level" from the internal level when needed. Databases as digital objects contain three layers of information which must be stored: the data, the structure, and the semantics. Proper storage of all three layers is needed for future preservation and longevity of the database. Putting data into permanent storage is generally the responsibility of the database engine a. k. a." storage engine". Though typically accessed by a DBMS through the underlying operating system( and often using the operating systems' file systems as intermediates for storage layout), storage properties and configuration setting are extremely important for the efficient operation of the DBMS, and thus are closely maintained by database administrators. A DBMS, while in operation, always has its database residing in several types of storage( e. g., memory and external storage). The database data and the additional needed information, possibly in very large amounts, are coded into bits. Data typically reside in the storage in structures that look completely different from the way the data look in the conceptual and external levels, but in ways that attempt to optimize( the best possible) these levels' reconstruction when needed by users and programs, as well as for computing additional types of needed information from the data( e. g., when querying the database). Some DBMSs support specifying which character encoding was used to store data, so multiple encodings can be used in the same database. Various low- level database storage structures are used by the storage engine to serialize the data model so it can be written to the medium of choice. Techniques such as indexing may be used to improve performance. Conventional storage is row- oriented, but there are also column- oriented and correlation databases. Materialized views. Often storage redundancy is employed to increase performance. A common example is storing" materialized views", which consist of frequently needed" external views" or query results. Storing such views saves the expensive computing of them each time they are needed. The downsides of materialized views are the overhead incurred when updating them to keep them synchronized with their original updated database data, and the cost of storage redundancy. Replication. Occasionally a database employs storage redundancy by database objects replication( with one or more copies) to increase data availability( both to improve performance of simultaneous multiple end- user accesses to a same database object, and to provide resiliency in a case of partial failure of a distributed database). Updates of a replicated object need to be synchronized across the object copies. In many cases, the entire database is replicated. Security. Database security deals with all various aspects of protecting the database content, its owners, and its users. It | ranges from protection from intentional |
unauthorized database uses to unintentional database accesses by unauthorized entities( e. g., a person or a computer program). Database access control deals with controlling who( a person or a certain computer program) is allowed to access what information in the database. The information may comprise specific database objects( e. g., record types, specific records, data structures), certain computations over certain objects( e. g., query types, or specific queries), or using specific access paths to the former( e. g., using specific indexes or other data structures to access information). Database access controls are set by special authorized( by the database owner) personnel that uses dedicated protected security DBMS interfaces. This may be managed directly on an individual basis, or by the assignment of individuals and privileges to groups, or( in the most elaborate models) through the assignment of individuals and groups to roles which are then granted entitlements. Data security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database or subsets of it called" subschemas". For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data. If the DBMS provides a way to interactively enter and update the database, as well as interrogate it, this capability allows for managing personal databases. Data security in general deals with protecting specific chunks of data, both physically( i. e., from corruption, or destruction, or removal; e. g., see physical security), or the interpretation of them, or parts of them to meaningful information( e. g., by looking at the strings of bits that they comprise, concluding specific valid credit- card numbers; e. g., see data encryption). Change and access logging records who accessed which attributes, what was changed, and when it was changed. Logging services allow for a forensic database audit later by keeping a record of access occurrences and changes. Sometimes application- level code is used to record changes rather than leaving this to the database. Monitoring can be set up to attempt to detect security breaches. Transactions and concurrency. Database transactions can be used to introduce some level of fault tolerance and data integrity after recovery from a crash. A database transaction is a unit of work, typically encapsulating a number of operations over a database( e. g., reading a database object, writing, acquiring or releasing a lock, etc.), an abstraction supported in database and also other systems. Each transaction has well defined boundaries in terms of which program/ code executions are included in that transaction( determined by the transaction' s programmer via special transaction commands). The acronym ACID describes some ideal properties of a database transaction: atomicity, consistency, isolation, and durability. Migration. A database built with one DBMS is not portable to another DBMS( i. e., the other DBMS cannot run it). However, in some situations, it is desirable to migrate a database from one DBMS to another. The reasons are primarily economical( different DBMSs may | have different total costs of |
ownership or TCOs), functional, and operational( different DBMSs may have different capabilities). The migration involves the database' s transformation from one DBMS type to another. The transformation should maintain( if possible) the database related application( i. e., all related application programs) intact. Thus, the database' s conceptual and external architectural levels should be maintained in the transformation. It may be desired that also some aspects of the architecture internal level are maintained. A complex or large database migration may be a complicated and costly( one- time) project by itself, which should be factored into the decision to migrate. This in spite of the fact that tools may exist to help migration between specific DBMSs. Typically, a DBMS vendor provides tools to help importing databases from other popular DBMSs. Building, maintaining, and tuning. After designing a database for an application, the next stage is building the database. Typically, an appropriate general- purpose DBMS can be selected to be used for this purpose. A DBMS provides the needed user interfaces to be used by database administrators to define the needed application' s data structures within the DBMS' s respective data model. Other user interfaces are used to select needed DBMS parameters( like security related, storage allocation parameters, etc.). When the database is ready( all its data structures and other needed components are defined), it is typically populated with initial application' s data( database initialization, which is typically a distinct project; in many cases using specialized DBMS interfaces that support bulk insertion) before making it operational. In some cases, the database becomes operational while empty of application data, and data are accumulated during its operation. After the database is created, initialized and populated it needs to be maintained. Various database parameters may need changing and the database may need to be tuned( tuning) for better performance; application' s data structures may be changed or added, new related application programs may be written to add to the application' s functionality, etc. Backup and restore. Sometimes it is desired to bring a database back to a previous state( for many reasons, e. g., cases when the database is found corrupted due to a software error, or if it has been updated with erroneous data). To achieve this, a backup operation is done occasionally or continuously, where each desired database state( i. e., the values of its data and their embedding in database' s data structures) is kept within dedicated backup files( many techniques exist to do this effectively). When it is decided by a database administrator to bring the database back to this state( e. g., by specifying this state by a desired point in time when the database was in this state), these files are used to restore that state. Static analysis. Static analysis techniques for software verification can be applied also in the scenario of query languages. In particular, the* Abstract interpretation framework has been extended to the field of query languages for relational databases as a way to support sound approximation techniques. The semantics of query languages can be tuned according to suitable abstractions | of the concrete domain of |
data. The abstraction of relational database system has many interesting applications, in particular, for security purposes, such as fine grained access control, watermarking, etc. Miscellaneous features. Other DBMS features might include: Increasingly, there are calls for a single system that incorporates all of these core functionalities into the same build, test, and deployment framework for database management and source control. Borrowing from other developments in the software industry, some market such offerings as" DevOps for database". Design and modeling. The first task of a database designer is to produce a conceptual data model that reflects the structure of the information to be held in the database. A common approach to this is to develop an entity– relationship model, often with the aid of drawing tools. Another popular approach is the Unified Modeling Language. A successful data model will accurately reflect the possible state of the external world being modeled: for example, if people can have more than one phone number, it will allow this information to be captured. Designing a good conceptual data model requires a good understanding of the application domain; it typically involves asking deep questions about the things of interest to an organization, like" can a customer also be a supplier?", or" if a product is sold with two different forms of packaging, are those the same product or different products?", or" if a plane flies from New York to Dubai via Frankfurt, is that one flight or two( or maybe even three)?". The answers to these questions establish definitions of the terminology used for entities( customers, products, flights, flight segments) and their relationships and attributes. Producing the conceptual data model sometimes involves input from business processes, or the analysis of workflow in the organization. This can help to establish what information is needed in the database, and what can be left out. For example, it can help when deciding whether the database needs to hold historic data as well as current data. Having produced a conceptual data model that users are happy with, the next stage is to translate this into a schema that implements the relevant data structures within the database. This process is often called logical database design, and the output is a logical data model expressed in the form of a schema. Whereas the conceptual data model is( in theory at least) independent of the choice of database technology, the logical data model will be expressed in terms of a particular database model supported by the chosen DBMS.( The terms" data model" and" database model" are often used interchangeably, but in this article we use" data model" for the design of a specific database, and" database model" for the modeling notation used to express that design). The most popular database model for general- purpose databases is the relational model, or more precisely, the relational model as represented by the SQL language. The process of creating a logical database design using this model uses a methodical approach known as normalization. The goal of normalization is to ensure that each elementary" fact" is only recorded in one | place, so that insertions, updates, |
and deletions automatically maintain consistency. The final stage of database design is to make the decisions that affect performance, scalability, recovery, security, and the like, which depend on the particular DBMS. This is often called" physical database design", and the output is the physical data model. A key goal during this stage is data independence, meaning that the decisions made for performance optimization purposes should be invisible to end- users and applications. There are two types of data independence: Physical data independence and logical data independence. Physical design is driven mainly by performance requirements, and requires a good knowledge of the expected workload and access patterns, and a deep understanding of the features offered by the chosen DBMS. Another aspect of physical database design is security. It involves both defining access control to database objects as well as defining security levels and methods for the data itself. Models. A database model is a type of data model that determines the logical structure of a database and fundamentally determines in which manner data can be stored, organized, and manipulated. The most popular example of a database model is the relational model( or the SQL approximation of relational), which uses a table- based format. Common logical data models for databases include: An object– relational database combines the two related structures. Physical data models include: Other models include: Specialized models are optimized for particular types of data: External, conceptual, and internal views. A database management system provides three views of the database data: While there is typically only one conceptual( or logical) and physical( or internal) view of the data, there can be any number of different external views. This allows users to see database information in a more business- related way rather than from a technical, processing viewpoint. For example, a financial department of a company needs the payment details of all employees as part of the company' s expenses, but does not need details about employees that are the interest of the human resources department. Thus different departments need different" views" of the company' s database. The three- level database architecture relates to the concept of" data independence" which was one of the major initial driving forces of the relational model. The idea is that changes made at a certain level do not affect the view at a higher level. For example, changes in the internal level do not affect application programs written using conceptual level interfaces, which reduces the impact of making physical changes to improve performance. The conceptual view provides a level of indirection between internal and external. On one hand it provides a common view of the database, independent of different external view structures, and on the other hand it abstracts away details of how the data are stored or managed( internal level). In principle every level, and even every external view, can be presented by a different data model. In practice usually a given DBMS uses the same data model for both the external and the conceptual levels( e. g., relational model). The internal level, which is hidden inside | the DBMS and depends on |
its implementation, requires a different level of detail and uses its own types of data structure types. Separating the" external"," conceptual" and" internal"levelswasamajorfeatureoftherelationaldatabasemodelimplementationsthatdominate21st century databases. Research.Databasetechnologyhasbeenanactiveresearchtopicsincethe1960s, both in academia and in the research and development groups of companies( for example IBM Research). Research activity includes theory and development of prototypes. Notable research topics have included models, the atomic transaction concept, and related concurrency control techniques, query languages and query optimization methods, RAID, and more. The database research area has several dedicated academic journals( for example," ACM Transactions on Database Systems"- TODS," Data and Knowledge Engineering"- DKE) and annual conferences( e. g., ACM SIGMOD, ACM PODS, VLDB, IEEE ICDE). In electromagnetism, there are two kinds of dipoles: Dipoles, whether electric or magnetic, can be characterized by their dipole moment, a vector quantity. For the simple electric dipole, the electric dipole moment points from the negative charge towards the positive charge, and has a magnitude equal to the strength of each charge times the separation between the charges.( To be precise: for the definition of the dipole moment, one should always consider the" dipole limit", where, for example, the distance of the generating charges should" converge" to 0 while simultaneously, the charge strength should" diverge" to infinity in such a way that the product remains a positive constant.) For the magnetic( dipole) current loop, the magnetic dipole moment points through the loop( according to the right hand grip rule), with a magnitude equal to the current in the loop times the area of the loop. Similar to magnetic current loops, the electron particle and some other fundamental particles have magnetic dipole moments, as an electron generates a magnetic field identical to that generated by a very small current loop. However, an electron' s magnetic dipole moment is not due to a current loop, but to an intrinsic property of the electron. The electron may also have an" electric" dipole moment though such has yet to be observed( see electron electric dipole moment). A permanent magnet, such as a bar magnet, owes its magnetism to the intrinsic magnetic dipole moment of the electron. The two ends of a bar magnet are referred to as poles— not to be confused with monopoles, see Classification below)— and may be labeled" north" and" south". In terms of the Earth' s magnetic field, they are respectively" north- seeking" and" south- seeking" poles: if the magnet were freely suspended in the Earth' s magnetic field, the north- seeking pole would point towards the north and the south- seeking pole would point towards the south. The dipole moment of the bar magnet points from its magnetic south to its magnetic north pole. In a magnetic compass, the north pole of a bar magnet points north. However, that means that Earth' s geomagnetic north pole is the" south" pole( south- seeking pole) of its dipole moment and vice versa. The only known mechanisms for the creation of magnetic dipoles are by current loops or quantum- mechanical spin since the existence of magnetic monopoles has never been experimentally demonstrated. The term comes from | the Greek(" dis")," twice" and(" |
polos")," axis". Classification. A" physical dipole" consists of two equal and opposite point charges: in the literal sense, two poles. Its field at large distances( i. e., distances large in comparison to the separation of the poles) depends almost entirely on the dipole moment as defined above. A" point( electric) dipole" is the limit obtained by letting the separation tend to 0 while keeping the dipole moment fixed. The field of a point dipole has a particularly simple form, and the order- 1 term in the multipole expansion is precisely the point dipole field. Although there are no known magnetic monopoles in nature, there are magnetic dipoles in the form of the quantum- mechanical spin associated with particles such as electrons( although the accurate description of such effects falls outside of classical electromagnetism). A theoretical magnetic" point dipole" has a magnetic field of exactly the same form as the electric field of an electric point dipole. A very small current- carrying loop is approximately a magnetic point dipole; the magnetic dipole moment of such a loop is the product of the current flowing in the loop and the( vector) area of the loop. Any configuration of charges or currents has a' dipole moment', which describes the dipole whose field is the best approximation, at large distances, to that of the given configuration. This is simply one term in the multipole expansion when the total charge(" monopole moment") is 0— as it" always" is for the magnetic case, since there are no magnetic monopoles. The dipole term is the dominant one at large distances: Its field falls off in proportion to, as compared to for the next( quadrupole) term and higher powers of for higher terms, or for the monopole term. Molecular dipoles. Many molecules have such dipole moments due to non- uniform distributions of positive and negative charges on the various atoms. Such is the case with polar compounds like hydrogen fluoride( HF), where electron density is shared unequally between atoms. Therefore, a molecule' s dipole is an electric dipole with an inherent electric field that should not be confused with a magnetic dipole which generates a magnetic field. The physical chemist Peter J. W. Debye was the first scientist to study molecular dipoles extensively, and, as a consequence, dipole moments are measured in units named" debye" in his honor. For molecules there are three types of dipoles: More generally, an induced dipole of" any" polarizable charge distribution" ρ"( remember that a molecule has a charge distribution) is caused by an electric field external to" ρ". This field may, for instance, originate from an ion or polar molecule in the vicinity of" ρ" or may be macroscopic( e. g., a molecule between the plates of a charged capacitor). The size of the induced dipole moment is equal to the product of the strength of the external field and the dipole polarizability of" ρ". Dipole moment values can be obtained from measurement of the dielectric constant. Some typical gas phase values in debye units are: Potassium bromide( KBr) has one of the highest | dipole moments because it is |
an ionic compound that exists as a molecule in the gas phase. The overall dipole moment of a molecule may be approximated as a vector sum of bond dipole moments. As a vector sum it depends on the relative orientation of the bonds, so that from the dipole moment information can be deduced about the molecular geometry. For example,thezerodipoleofCO2 implies that the two C= O bond dipole moments cancel so that the molecule must be linear.ForH2O the O− H bond moments do not cancel because the molecule is bent. For ozone(O3) which is also a bent molecule, the bond dipole moments are not zero even though the O− O bonds are between similar atoms. This agrees with the Lewis structures for the resonance forms of ozone which show a positive charge on the central oxygen atom. An example in organic chemistry of the role of geometry in determining dipole moment is the" cis" and" trans" isomers of 1, 2- dichloroethene. In the" cis" isomer the two polar C− Cl bonds are on the same side of the C= C double bond and the molecular dipole moment is 1. 90 D. In the" trans" isomer, the dipole moment is zero because the two C− Cl bonds are on opposite sides of the C= C and cancel( and the two bond moments for the much less polar C− H bonds also cancel). Another example of the role of molecular geometry is boron trifluoride, which has three polar bonds with a difference in electronegativity greater than the traditionally cited threshold of 1. 7 for ionic bonding. However, due to the equilateral triangular distribution of the fluoride ions about the boron cation center, the molecule as a whole does not exhibit any identifiable pole: one cannot construct a plane that divides the molecule into a net negative part and a net positive part. Quantum mechanical dipole operator. Consider a collection of" N" particles with charges" qi" and position vectors r" i". For instance, this collection may be a molecule consisting of electrons, all with charge−" e", and nuclei with charge" eZi", where" Zi" is the atomic number of the" i" th nucleus. The dipole observable( physical quantity) has the quantum mechanical dipole operator: Notice that this definition is valid only for neutral atoms or molecules, i. e. total charge equal to zero. In the ionized case,wehavewhereformula_3 is the center of mass of the molecule/ group of particles. Atomic dipoles. A non- degenerate(" S"- state) atom can have only a zero permanent dipole. This fact follows quantum mechanically from the inversion symmetry of atoms. All 3 components of the dipole operator are antisymmetric under inversion with respect to the nucleus,whereformula_5 isthedipoleoperatorandformula_6 is the inversion operator. The permanent dipole moment of an atom in a non- degenerate state( see degenerate energy level) is given as the expectation( average) value of the dipole operator,whereformula_8 is an" S"- state, non- degenerate, wavefunction, which is symmetric or antisymmetric under inversion:formula_9. Since the product of the wavefunction( in the ket) and its complex conjugate( in the bra) is always symmetric under inversion | and its inverse, it follows |
that the expectation value changes sign under inversion.Weusedherethefactthatformula_11, being a symmetry operator, is unitary:formula_12andbydefinitiontheHermitianadjointformula_13maybemovedfrombratoketandthenbecomesformula_14. Since the only quantity that is equal to minus itself is the zero, the expectation value vanishes, In the case of open- shell atoms with degenerate energy levels, one could define a dipole moment by the aid of the first- order Stark effect. This gives a non- vanishing dipole( by definition proportional to a non- vanishing first- order Stark shift) only if some of the wavefunctions belonging to the degenerate energies have opposite parity; i. e., have different behavior under inversion. This is a rare occurrence, but happens for the excited H- atom,where2sand2p states are" accidentally" degenerate( see article Laplace– Runge– Lenz vector for the origin of this degeneracy) and have opposite parity(2sisevenand2p is odd). Field of a static magnetic dipole. Magnitude. The far- field strength," B", of a dipole magnetic field is given bywhereConversion to cylindrical coordinates is achieved using andwhere" ρ" is the perpendicular distance from the" z"- axis. Then, Vector form. The field itself is a vector quantity: whereThis is" exactly" the field of a point dipole," exactly" the dipole term in the multipole expansion of an arbitrary field, and" approximately" the field of any dipole- like configuration at large distances. Magnetic vector potential. The vector potential A of a magnetic dipole iswith the same definitions as above. Field from an electric dipole. The electrostatic potential at position r due to an electric dipole at the origin is given by: where p is the( vector) dipole moment, and" є" 0 is the permittivity of free space. This term appears as the second term in the multipole expansion of an arbitrary electrostatic potential Φ( r). If the source of Φ( r) is a dipole, as it is assumed here, this term is the only non- vanishing term in the multipole expansion of Φ( r). The electric field from a dipole can be found from the gradient of this potential: This is of the same form of the expression for the magnetic field of a point magnetic dipole, ignoring the delta function. In a real electric dipole, however, the charges are physically separate and the electric field diverges or converges at the point charges. This is different to the magnetic field of a real magnetic dipole which is continuous everywhere. The delta function represents the strong field pointing in the opposite direction between the point charges, which is often omitted since one is rarely interested in the field at the dipole' s position. For further discussions about the internal field of dipoles, see or Magnetic moment# Internal magnetic field of a dipole. Torque on a dipole. Since the direction of an electric field is defined as the direction of the force on a positive charge, electric field lines point away from a positive charge and toward a negative charge. When placed in a homogeneous electric or magnetic field, equal but opposite forces arise on each side of the dipole creating a torque}: for an electric dipole moment p( in coulomb- meters), orfor a magnetic dipole moment m( | in ampere- square meters). The |
resulting torque will tend to align the dipole with the applied field, which in the case of an electric dipole, yields a potential energy ofThe energy of a magnetic dipole is similarlyDipole radiation. In addition to dipoles in electrostatics, it is also common to consider an electric or magnetic dipole that is oscillating in time. It is an extension, or a more physical next- step, to spherical wave radiation. In particular, consider a harmonically oscillating electric dipole, with angular frequency" ω" and a dipole moment" p" 0 along the ẑ direction of the formIn vacuum, the exact field produced by this oscillating dipole can be derived using the retarded potential formulation as: For≫ 1, the far- field takes the simpler form of a radiating" spherical" wave, but with angular dependence embedded in the cross- product: The time- averaged Poynting vectoris not distributed isotropically, but concentrated around the directions lying perpendicular to the dipole moment, as a result of the non- spherical electric and magnetic waves. In fact, the spherical harmonic function( sin" θ") responsible for such toroidal angular distribution is precisely the" l"= 1" p" wave. The total time- average power radiated by the field can then be derived from the Poynting vector asNotice that the dependence of the power on the fourth power of the frequency of the radiation is in accordance with the Rayleigh scattering, and the underlying effects why the sky consists of mainly blue colour. A circular polarized dipole is described as a superposition of two linear dipoles. Dynamics( from Greek δυναμικός" dynamikos"" powerful", from δύναμις" dynamis"" power") or dynamic may refer to: Draught beer, also spelt draft, is beer served from a cask or keg rather than from a bottle or can. Draught beer served from a pressurised keg is also known asName. Until Joseph Bramah patented the beer engine in 1785, beer was served directly from the barrel and carried to the customer. The Old English""(" carry; pull") developed into a series of related words including" drag"," draw", and" draught". By the time Bramah' s beer pumps became popular, the use of the term" draught" to refer to the acts of serving or drinking beer was well established and transferred easily to beer served via the hand pumps. In time, the word came to be restricted to only such beer. The usual spelling is now" draught" in the United Kingdom, Ireland, Australia, and New Zealand and more commonly" draft" in North America, although it can be spelt either way. Regardless of spelling, the word is pronounced or depending on the region the speaker is from. Canned draught is beer served from a pressurised container featuring a widget. Smooth flow( also known as cream flow, nitrokeg, or smooth) is the name brewers give to draught beers pressurised with a partial nitrogen gas blend. History. In 1691, an article in the" London Gazette" mentioned John Lofting, who held a patent for a fire engine:" The said patentee has also projected a very useful engine for starting of beer, and other liquors which will draw from 20 to 30 | barrels an hour, which are |
completely fixed with brass joints and screws at reasonable rates".Intheearly20th century, draught beer started to be served from pressurised containers. Artificial carbonation was introduced in the United Kingdom in 1936, with Watney' s experimental pasteurised beer Red Barrel.ThoughthismethodofservingbeerdidnottakeholdintheUKuntilthelate1950s, it did become the favored method in the rest of Europe, where it is known by such terms as" en pression". The carbonation method of serving beer subsequently spread to the rest of the world;bytheearly1970s the term" draught beer" almost exclusively referred to beer served under pressure as opposed to the traditional cask or barrel beer. In Britain, the Campaign for Real Ale( CAMRA) was founded in 1971 to protect traditional— unpressurised— beer and brewing methods. The group devised the term" real ale" to differentiate between beer served from the cask and beer served under pressure. The term" real ale" has since been expanded to include bottle- conditioned beer. Keg beer. Keg beer is often filtered and/ or pasteurised, both of which are processes that render the yeast inactive. In brewing parlance, a keg is different from a cask. A cask has a tap hole near the edge of the top, and a spile hole on the side used for conditioning the unfiltered and unpasteurised beer. A keg has a single opening in the centre of the top to which a flow pipe is attached. Kegs are artificially pressurised after fermentation with carbon dioxide or a mixture of carbon dioxide and nitrogen gas or especially in Czech Republic solely compressed air." Keg" has become a term of contempt used by some, particularly in the UK,sincethe1960s when pasteurised draught beers started replacing traditional cask beers. Keg beer was replacing traditional cask ale in all parts of the UK, primarily because it requires less care to handle. Since 1971, CAMRA has conducted a consumer campaign on behalf of those who prefer traditional cask beer. CAMRA has lobbied the British Parliament to ensure support for cask ale and microbreweries have sprung up to serve those consumers who prefer traditional cask beer.PressurisedCO2 in the keg' s headspace maintains carbonation in the beer.TheCO2pressurevariesdependingontheamountofCO2 already in the beer and the keg storage temperature.OccasionallytheCO2 gas is blended with nitrogen gas.CO2/ nitrogen blends are used to allow a higher operating pressure in complex dispensing systems. Nitrogen is used under high pressure when dispensing dry stouts( such as Guinness)andothercreamybeersbecauseitdisplacesCO2 to( artificially) form a rich tight head and a less carbonated taste. This makes the beer feel smooth on the palate and gives a foamy appearance. Premixed bottled gas for creamy beers is usually 75% nitrogen and 25%CO2. This premixed gas which only works well with creamy beers is often referred to as Guinness Gas, Beer Gas, or Aligal( an Air Liquide brand name). Using" Beer Gas" with other beer styles can cause the last 5% to 10% of the beer in each keg to taste very flat and lifeless. In the UK, the term" keg beer" would imply the beer is pasteurised, in contrast to unpasteurised cask ale. Some of the newer microbreweries may offer a nitro keg stout which is filtered but | not pasteurised. Storage and serving |
temperature. Cask beer should be stored and served at a cellar temperature of. Once a cask is opened, it should be consumed within three days. Keg beer is given additional cooling just prior to being served either by flash coolers or a remote cooler in the cellar. This chills the beer to temperatures between. Canned and bottled" draught". The words" draft" and" draught" have been used as marketing terms to describe canned or bottled beers, implying that they taste and appear like beers from a cask or keg. Commercial brewers use this as a marketing tool although it is incorrect to call any beer not drawn from a cask or keg" draught". Two examples are Miller Genuine Draft, a pale lager which is produced using a cold filtering system, and Guinness stout in patented" Draught- flow" cans and bottles. Guinness is an example of beers that use a nitrogen widget to create a smooth beer with a dense head. Guinness has recently replaced the widget system from their bottled" draught" beer with a coating of cellulose fibres on the inside of the bottle. Statements indicate a new development in bottling technology that enables the mixture of nitrogen and carbon dioxide to be present in the beer without using a widget, making it according to Guinness" more drinkable" from the bottle. In some countries, such as Japan, the term" draft" applied to canned or bottled beer indicates that the beer is not pasteurised( though it may be filtered), giving it a fresher taste but shorter shelf- life than conventional packaged beers. Director may refer to: Major depressive disorder( MDD), also known simply as depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self- esteem, and loss of interest or pleasure in normally enjoyable activities. Those affected may also occasionally have delusions or hallucinations. Introduced by a group of US clinicians in the mid-1970s, the term was adopted by the American Psychiatric Association for this symptom cluster under mood disorders in the 1980 version of the" Diagnostic and Statistical Manual of Mental Disorders"( DSM- III) classification, and has become widely used since. The diagnosis of major depressive disorder is based on the person' s reported experiences and a mental status examination. There is no laboratory test for the disorder, but testing may be done to rule out physical conditions that can cause similar symptoms. The most common time of onset is in a person's20s, with females affected about twice as often as males. The course of the disorder varies widely, from one episode lasting months to a lifelong disorder with recurrent major depressive episodes. Those with major depressive disorder are typically treated with psychotherapy and antidepressant medication. Medication appears to be effective, but the effect may only be significant in the most severely depressed. Hospitalization( which may be involuntary) may be necessary in cases with associated self- neglect or a significant risk of harm to self or others. Electroconvulsive therapy( ECT) may be considered if other measures are not effective. Major depressive disorder is believed to be | caused by a combination of |
genetic, environmental, and psychological factors, with about 40% of the risk being genetic. Risk factors include a family history of the condition, major life changes, certain medications, chronic health problems, and substance use disorders. It can negatively affect a person' s personal life, work life, or education as well as sleeping, eating habits, and general health. Major depressive disorder affected approximately 163 million people( 2% of the world' s population) in 2017. The percentage of people who are affected at one point in their life varies from 7% in Japan to 21% in France. Lifetime rates are higher in the developed world( 15%) compared to the developing world( 11%). The disorder causes the second- most years lived with disability, after lower back pain. Symptoms and signs. Major depression significantly affects a person' s family and personal relationships, work or school life, sleeping and eating habits, and general health. A person having a major depressive episode usually exhibits a low mood, which pervades all aspects of life, and an inability to experience pleasure in previously enjoyable activities. Depressed people may be preoccupied with— or ruminate over— thoughts and feelings of worthlessness, inappropriate guilt or regret, helplessness or hopelessness. Other symptoms of depression include poor concentration and memory, withdrawal from social situations and activities, reduced sex drive, irritability, and thoughts of death or suicide. Insomnia is common; in the typical pattern, a person wakes very early and cannot get back to sleep. Hypersomnia, or oversleeping, can also happen. Some antidepressants may also cause insomnia due to their stimulating effect. In severe cases, depressed people may have psychotic symptoms. These symptoms include delusions or, less commonly, hallucinations, usually unpleasant. People who have had previous episodes with psychotic symptoms are more likely to have them with future episodes. A depressed person may report multiple physical symptoms such as fatigue, headaches, or digestive problems; physical complaints are the most common presenting problem in developing countries, according to the World Health Organization' s criteria for depression. Appetite often decreases, resulting in weight loss, although increased appetite and weight gain occasionally occur. Family and friends may notice agitation or lethargy. Older depressed people may have cognitive symptoms of recent onset, such as forgetfulness, and a more noticeable slowing of movements. Depressed children may often display an irritable rather than a depressed mood; most lose interest in school and show a steep decline in academic performance. Diagnosis may be delayed or missed when symptoms are interpreted as" normal moodiness." Cause. The biopsychosocial model proposes that biological, psychological, and social factors all play a role in causing depression. The diathesis– stress model specifies that depression results when a preexisting vulnerability, or diathesis, is activated by stressful life events. The preexisting vulnerability can be either genetic, implying an interaction between nature and nurture, or schematic, resulting from views of the world learned in childhood. Adverse childhood experiences( incorporating childhood abuse, neglect and family dysfunction) markedly increase the risk of major depression, especially if more than one type. Childhood trauma also correlates with severity of depression, poor responsiveness to treatment and length of | illness. Some are more susceptible |
than others to developing mental illness such as depression after trauma, and various genes have been suggested to control susceptibility. Genetics. Family and twin studies find that nearly 40% of individual differences in risk for major depressive disorder can be explained by genetic factors. Like most psychiatric disorders, major depressive disorder is likely influenced by many individual genetic changes. In 2018, a genome- wide association study discovered 44 genetic variants linked to risk for major depression; a 2019 study found 102 variants in the genome linked to depression. Research focusing on specific candidate genes has been criticized for its tendency to generate false positive findings. There are also other efforts to examine interactions between life stress and polygenic risk for depression. Other health problems. Depression can also come secondary to a chronic or terminal medical condition, such as HIV/ AIDS or asthma, and may be labeled" secondary depression." It is unknown whether the underlying diseases induce depression through effect on quality of life, or through shared etiologies( such as degeneration of the basal ganglia in Parkinson' s disease or immune dysregulation in asthma). Depression may also be iatrogenic( the result of healthcare), such as drug- induced depression. Therapies associated with depression include interferons, beta- blockers, isotretinoin, contraceptives, cardiac agents, anticonvulsants, antimigraine drugs, antipsychotics, and hormonal agents such as gonadotropin- releasing hormone agonist. Substance use in early age is associated with increased risk of developing depression later in life. Depression occurring after giving birth is called postpartum depression and is thought to be the result of hormonal changes associated with pregnancy. Seasonal affective disorder, a type of depression associated with seasonal changes in sunlight, is thought to be triggered by decreased sunlight.VitaminB2,B6andB12 deficiency may cause depression in females. Pathophysiology. The pathophysiology of depression is not yet understood, but current theories center around monoaminergic systems, the circadian rhythm, immunological dysfunction, HPA- axis dysfunction and structural or functional abnormalities of emotional circuits. Derived from the effectiveness of monoaminergic drugs in treating depression, the monoamine theory posits that insufficient activity of monoamine neurotransmitters is the primary cause of depression. Evidence for the monoamine theory comes from multiple areas. First, acute depletion of tryptophan— a necessary precursor of serotonin and a monoamine— can cause depression in those in remission or relatives of people who are depressed, suggesting that decreased serotonergic neurotransmission is important in depression. Second, the correlation between depression risk and polymorphisms in the 5- HTTLPR gene, which codes for serotonin receptors, suggests a link. Third, decreased size of the locus coeruleus, decreased activity of tyrosine hydroxylase, increased density of alpha- 2 adrenergic receptor, and evidence from rat models suggest decreased adrenergic neurotransmission in depression. Furthermore, decreased levels of homovanillic acid, altered response to dextroamphetamine, responses of depressive symptoms to dopamine receptor agonists, decreaseddopaminereceptorD1 binding in the striatum, and polymorphism of dopamine receptor genes implicate dopamine, another monoamine, in depression. Lastly, increased activity of monoamine oxidase, which degrades monoamines, has been associated with depression. However, the monoamine theory is inconsistent with observations that serotonin depletion does not cause depression in healthy persons, that antidepressants instantly increase | levels of monoamines but take |
weeks to work, and the existence of atypical antidepressants which can be effective despite not targeting this pathway. One proposed explanation for the therapeutic lag, and further support for the deficiency of monoamines, is a desensitization of self- inhibition in raphe nuclei by the increased serotonin mediated by antidepressants. However, disinhibition of the dorsal raphe has been proposed to occur as a result of" decreased" serotonergic activity in tryptophan depletion, resulting in a depressed state mediated by increased serotonin. Further countering the monoamine hypothesis is the fact that rats with lesions of the dorsal raphe are not more depressive than controls, the finding of increased jugular 5- HIAA in people who are depressed that normalized with SSRI treatment, and the preference for carbohydrates in people who are depressed. Already limited, the monoamine hypothesis has been further oversimplified when presented to the general public. Immune system abnormalities have been observed, including increased levels of cytokines involved in generating sickness behavior( which shares overlap with depression). The effectiveness of nonsteroidal anti- inflammatory drugs( NSAIDs) and cytokine inhibitors in treating depression, and normalization of cytokine levels after successful treatment further suggest immune system abnormalities in depression. HPA-axisabnormalitieshavebeensuggestedindepressiongiventheassociationofCRHR1 with depression and the increased frequency of dexamethasone test non- suppression in people who are depressed. However, this abnormality is not adequate as a diagnosis tool, because its sensitivity is only 44%. These stress- related abnormalities are thought to be the cause of hippocampal volume reductions seen in people who are depressed. Furthermore, a meta- analysis yielded decreased dexamethasone suppression, and increased response to psychological stressors. Further abnormal results have been obscured with the cortisol awakening response, with increased response being associated with depression. Theories unifying neuroimaging findings have been proposed. The first model proposed is the limbic- cortical model, which involves hyperactivity of the ventral paralimbic regions and hypoactivity of frontal regulatory regions in emotional processing. Another model, the cortico- striatal model, suggests that abnormalities of the prefrontal cortex in regulating striatal and subcortical structures results in depression. Another model proposes hyperactivity of salience structures in identifying negative stimuli, and hypoactivity of cortical regulatory structures resulting in a negative emotional bias and depression, consistent with emotional bias studies. Diagnosis. Clinical assessment. A diagnostic assessment may be conducted by a suitably trained general practitioner, or by a psychiatrist or psychologist, who records the person' s current circumstances, biographical history, current symptoms, family history, and alcohol and drug use. The assessment also includes a mental state examination, which is an assessment of the person' s current mood and thought content, in particular the presence of themes of hopelessness or pessimism, self- harm or suicide, and an absence of positive thoughts or plans. Specialist mental health services are rare in rural areas, and thus diagnosis and management is left largely to primary- care clinicians. This issue is even more marked in developing countries. Rating scales are not used to diagnose depression, but they provide an indication of the severity of symptoms for a time period, so a person who scores above a given cut- off point can be more thoroughly | evaluated for a depressive disorder |
diagnosis. Several rating scales are used for this purpose; these include the Hamilton Rating Scale for Depression, the Beck Depression Inventory or the Suicide Behaviors Questionnaire- Revised. Primary- care physicians have more difficulty with underrecognition and undertreatment of depression compared to psychiatrists. These cases may be missed because for some people with depression, physical symptoms often accompany depression. In addition, there may also be barriers related to the person, provider, and/ or the medical system. Non- psychiatrist physicians have been shown to miss about two- thirds of cases, although there is some evidence of improvement in the number of missed cases. Before diagnosing major depressive disorder, a doctor generally performs a medical examination and selected investigations to rule out other causes of symptoms. These include blood tests measuring TSH and thyroxine to exclude hypothyroidism; basic electrolytes and serum calcium to rule out a metabolic disturbance; and a full blood count including ESR to rule out a systemic infection or chronic disease. Adverse affective reactions to medications or alcohol misuse may be ruled out, as well. Testosterone levels may be evaluated to diagnose hypogonadism, a cause of depression in men. Vitamin D levels might be evaluated, as low levels of vitamin D have been associated with greater risk for depression. Subjective cognitive complaints appear in older depressed people, but they can also be indicative of the onset of a dementing disorder, such as Alzheimer' s disease. Cognitive testing and brain imaging can help distinguish depression from dementia. A CT scan can exclude brain pathology in those with psychotic, rapid- onset or otherwise unusual symptoms. No biological tests confirm major depression. In general, investigations are not repeated for a subsequent episode unless there is a medical indication. DSM and ICD criteria. The most widely used criteria for diagnosing depressive conditions are found in the American Psychiatric Association' s" Diagnostic and Statistical Manual of Mental Disorders" and the World Health Organization' s" International Statistical Classification of Diseases and Related Health Problems". The latter system is typically used in European countries, while the former is used in the US and many other non- European nations, and the authors of both have worked towards conforming one with the other. Both DSM- 5 and ICD- 10 mark out typical( main) depressive symptoms. ICD- 10 defines three typical depressive symptoms( depressed mood, anhedonia, and reduced energy), two of which should be present to determine the depressive disorder diagnosis. According to DSM- 5, there are two main depressive symptoms: a depressed mood, and loss of interest/ pleasure in activities( anhedonia). These symptoms, as well as five out of the nine more specific symptoms listed, must frequently occur for more than two weeks( to the extent in which it impairs functioning) for the diagnosis. Major depressive disorder is classified as a mood disorder in DSM- 5. The diagnosis hinges on the presence of single or recurrent major depressive episodes. Further qualifiers are used to classify both the episode itself and the course of the disorder. The category Unspecified Depressive Disorder is diagnosed if the depressive episode' s manifestation does not meet | the criteria for a major |
depressive episode. The ICD- 10 system does not use the term" major depressive disorder" but lists very similar criteria for the diagnosis of a depressive episode( mild, moderate or severe); the term" recurrent" may be added if there have been multiple episodes without mania. Major depressive episode. A major depressive episode is characterized by the presence of a severely depressed mood that persists for at least two weeks. Episodes may be isolated or recurrent and are categorized as mild( few symptoms in excess of minimum criteria), moderate, or severe( marked impact on social or occupational functioning). An episode with psychotic features— commonly referred to as" psychotic depression"— is automatically rated as severe. If the person has had an episode of mania or markedly elevated mood, a diagnosis of bipolar disorder is made instead. Depression without mania is sometimes referred to as" unipolar" because the mood remains at one emotional state or" pole". Bereavement is not an exclusion criterion in DSM- 5, and it is up to the clinician to distinguish between normal reactions to a loss and MDD. Excluded are a range of related diagnoses, including dysthymia, which involves a chronic but milder mood disturbance; recurrent brief depression, consisting of briefer depressive episodes; minor depressive disorder, whereby only some symptoms of major depression are present; and adjustment disorder with depressed mood, which denotes low mood resulting from a psychological response to an identifiable event or stressor. Subtypes. The DSM- 5 recognizes six further subtypes of MDD, called" specifiers", in addition to noting the length, severity and presence of psychotic features: Differential diagnoses. To confirm major depressive disorder as the most likely diagnosis, other potential diagnoses must be considered, including dysthymia, adjustment disorder with depressed mood, or bipolar disorder. Dysthymia is a chronic, milder mood disturbance in which a person reports a low mood almost daily over a span of at least two years. The symptoms are not as severe as those for major depression, although people with dysthymia are vulnerable to secondary episodes of major depression( sometimes referred to as" double depression"). Adjustment disorder with depressed mood is a mood disturbance appearing as a psychological response to an identifiable event or stressor, in which the resulting emotional or behavioral symptoms are significant but do not meet the criteria for a major depressive episode. Bipolar disorder, previously known as" manic– depressive disorder", is a condition in which depressive phases alternate with periods of mania or hypomania. Although depression is currently categorized as a separate disorder, there is ongoing debate because individuals diagnosed with major depression often experience some hypomanic symptoms, indicating a mood disorder continuum. Other disorders need to be ruled out before diagnosing major depressive disorder. They include depressions due to physical illness, medications, and substance use disorders. Depression due to physical illness is diagnosed as a mood disorder due to a general medical condition. This condition is determined based on history, laboratory findings, or physical examination. When the depression is caused by a medication, non- medical use of a psychoactive substance, or exposure to a toxin, it is then diagnosed as | a specific mood disorder( previously |
called" substance- induced mood disorder"). Screening and prevention. Preventive efforts may result in decreases in rates of the condition of between 22 and 38%. Since 2016, the United States Preventive Services Task Force( USPSTF) has recommended screening for depression among those over the age 12; though a 2005 Cochrane review found that the routine use of screening questionnaires has little effect on detection or treatment. Screening the general population is not recommended by authorities in the UK or Canada. Behavioral interventions, such as interpersonal therapy and cognitive- behavioral therapy, are effective at preventing new onset depression. Because such interventions appear to be most effective when delivered to individuals or small groups, it has been suggested that they may be able to reach their large target audience most efficiently through the Internet. The Netherlands mental health care system provides preventive interventions, such as the" Coping with Depression" course( CWD) for people with sub- threshold depression. The course is claimed to be the most successful of psychoeducational interventions for the treatment and prevention of depression( both for its adaptability to various populations and its results), with a risk reduction of 38% in major depression and an efficacy as a treatment comparing favorably to other psychotherapies. Management. The three most common treatments for depression are psychotherapy, medication, and electroconvulsive therapy. Psychotherapy is the treatment of choice( over medication) for people under 18. The UK National Institute for Health and Care Excellence( NICE) 2004 guidelines indicate that antidepressants should not be used for the initial treatment of mild depression because the risk- benefit ratio is poor. The guidelines recommend that antidepressants treatment in combination with psychosocial interventions should be considered for: The guidelines further note that antidepressant treatment should be continued for at least six months to reduce the risk of relapse, and that SSRIs are better tolerated than tricyclic antidepressants. American Psychiatric Association treatment guidelines recommend that initial treatment should be individually tailored based on factors including severity of symptoms, co- existing disorders, prior treatment experience, and personal preference. Options may include pharmacotherapy, psychotherapy, exercise, electroconvulsive therapy( ECT), transcranial magnetic stimulation( TMS) or light therapy. Antidepressant medication is recommended as an initial treatment choice in people with mild, moderate, or severe major depression, and should be given to all people with severe depression unless ECT is planned. There is evidence that collaborative care by a team of health care practitioners produces better results than routine single- practitioner care. Treatment options are much more limited in developing countries, where access to mental health staff, medication, and psychotherapy is often difficult. Development of mental health services is minimal in many countries; depression is viewed as a phenomenon of the developed world despite evidence to the contrary, and not as an inherently life- threatening condition. There is insufficient evidence to determine the effectiveness of psychological versus medical therapy in children. Lifestyle. Physical exercise has been found to be effective for major depression, and may be recommended to people who are willing, motivated, and healthy enough to participate in an exercise program as treatment. It is equivalent to the | use of medications or psychological |
therapies in most people. In older people it does appear to decrease depression. Sleep and diet may also play a role in depression, and interventions in these areas may be an effective add- on to conventional methods. In observational studies, smoking cessation has benefits in depression as large as or larger than those of medications. Talking therapies. Talking therapy( psychotherapy) can be delivered to individuals, groups, or families by mental health professionals, including psychotherapists, psychiatrists, psychologists, clinical social workers, counselors, and psychiatric nurses. A 2012 review found psychotherapy to be better than no treatment but not other treatments. With more complex and chronic forms of depression, a combination of medication and psychotherapy may be used. There is moderate- quality evidence that psychological therapies are a useful addition to standard antidepressant treatment of treatment- resistant depression in the short term. Psychotherapy has been shown to be effective in older people. Successful psychotherapy appears to reduce the recurrence of depression even after it has been stopped or replaced by occasional booster sessions. The most- studied form of psychotherapy for depression is CBT, which teaches clients to challenge self- defeating, but enduring ways of thinking( cognitions) and change counter- productive behaviors. CBT can perform as well as than antidepressants in people with major depression. CBT has the most research evidence for the treatment of depression in children and adolescents, and CBT and interpersonal psychotherapy( IPT) are preferred therapies for adolescent depression. In people under 18, according to the National Institute for Health and Clinical Excellence, medication should be offered only in conjunction with a psychological therapy, such as CBT, interpersonal therapy, or family therapy. Several variables predict success for cognitive behavioral therapy in adolescents: higher levels of rational thoughts, less hopelessness, fewer negative thoughts, and fewer cognitive distortions. CBT is particularly beneficial in preventing relapse. Cognitive behavioral therapy and occupational programs( including modification of work activities and assistance) have been shown to be effective in reducing sick days taken by workers with depression. Several variants of cognitive behavior therapy have been used in those with depression, the most notable being rational emotive behavior therapy, and mindfulness- based cognitive therapy. Mindfulness- based stress reduction programs may reduce depression symptoms. Mindfulness programs also appear to be a promising intervention in youth. Psychoanalysis is a school of thought, founded by Sigmund Freud, which emphasizes the resolution of unconscious mental conflicts. Psychoanalytic techniques are used by some practitioners to treat clients presenting with major depression. A more widely practiced therapy, called psychodynamic psychotherapy, is in the tradition of psychoanalysis but less intensive, meeting once or twice a week. It also tends to focus more on the person' s immediate problems, and has an additional social and interpersonal focus. In a meta- analysis of three controlled trials of Short Psychodynamic Supportive Psychotherapy, this modification was found to be as effective as medication for mild to moderate depression. Antidepressants. Conflicting results have arisen from studies that look at the effectiveness of antidepressants in people with acute, mild to moderate depression. A review commissioned by the National Institute for Health and Care | Excellence( UK) concluded that there |
is strong evidence that selective serotonin reuptake inhibitors( SSRIs), such as escitalopram, paroxetine, and sertraline, have greater efficacy than placebo on achieving a 50% reduction in depression scores in moderate and severe major depression, and that there is some evidence for a similar effect in mild depression. Similarly, a Cochrane systematic review of clinical trials of the generic tricyclic antidepressant amitriptyline concluded that there is strong evidence that its efficacy is superior to placebo. In 2014 the U. S. Food and Drug Administration published a systematic review of all antidepressant maintenance trials submitted to the agency between 1985 and 2012. The authors concluded that maintenance treatment reduced the risk of relapse by 52% compared to placebo, and that this effect was primarily due to recurrent depression in the placebo group rather than a drug withdrawal effect. To find the most effective antidepressant medication with minimal side- effects, the dosages can be adjusted, and if necessary, combinations of different classes of antidepressants can be tried. Response rates to the first antidepressant administered range from 50 to 75%, and it can take at least six to eight weeks from the start of medication to improvement. Antidepressant medication treatment is usually continued for 16 to 20 weeks after remission, to minimize the chance of recurrence, and even up to one year of continuation is recommended. People with chronic depression may need to take medication indefinitely to avoid relapse. SSRIs are the primary medications prescribed, owing to their relatively mild side- effects, and because they are less toxic in overdose than other antidepressants. People who do not respond to one SSRI can be switched to another antidepressant, and this results in improvement in almost 50% of cases. Another option is to switch to the atypical antidepressant bupropion. Venlafaxine, an antidepressant with a different mechanism of action, may be modestly more effective than SSRIs. However, venlafaxine is not recommended in the UK as a first- line treatment because of evidence suggesting its risks may outweigh benefits, and it is specifically discouraged in children and adolescents. For children, some research has supported the use of the SSRI antidepressant fluoxetine. The benefit however appears to be slight in children, while other antidepressants have not been shown to be effective. Medications are not recommended in children with mild disease. There is also insufficient evidence to determine effectiveness in those with depression complicated by dementia. Any antidepressant can cause low blood sodium levels; nevertheless, it has been reported more often with SSRIs. It is not uncommon for SSRIs to cause or worsen insomnia; the sedating atypical antidepressant mirtazapine can be used in such cases. Irreversible monoamine oxidase inhibitors, an older class of antidepressants, have been plagued by potentially life- threatening dietary and drug interactions. They are still used only rarely, although newer and better- tolerated agents of this class have been developed. The safety profile is different with reversible monoamine oxidase inhibitors, such as moclobemide, where the risk of serious dietary interactions is negligible and dietary restrictions are less strict. It is unclear whether antidepressants affect a person' s risk of | suicide. For children, adolescents, and |
probably young adults between 18 and 24 years old, there is a higher risk of both suicidal ideations and suicidal behavior in those treated with SSRIs. For adults, it is unclear whether SSRIs affect the risk of suicidality. One review found no connection; another an increased risk; and a third no risk in those 25– 65 years old and a decreased risk in those more than 65. A black box warning was introduced in the United States in 2007 on SSRIs and other antidepressant medications due to the increased risk of suicide in people younger than 24 years old. Similar precautionary notice revisions were implemented by the Japanese Ministry of Health. Other medications. A 2019 Cochrane review on the combined use of antidepressants plus benzodiazepines demonstrated improved effectiveness when compared to antidepressants alone; however, these effects were not maintained in the acute or continuous phase. The benefits of adding a benzodiazepine should be balanced against possible harms and other alternative treatment strategies when antidepressant mono- therapy is considered inadequate. There is some evidence that omega- 3 fatty acids fish oil supplements containing high levels of eicosapentaenoic acid( EPA) to docosahexaenoic acid( DHA) are effective in the treatment of, but not the prevention of major depression. However, a Cochrane review determined there was insufficient high quality evidence to suggest omega- 3 fatty acids were effective in depression. There is limited evidence that vitamin D supplementation is of value in alleviating the symptoms of depression in individuals who are vitamin D- deficient. There is some preliminary evidence that COX- 2 inhibitors, such as celecoxib, have a beneficial effect on major depression. Lithium appears effective at lowering the risk of suicide in those with bipolar disorder and unipolar depression to nearly the same levels as the general population. There is a narrow range of effective and safe dosages of lithium thus close monitoring may be needed. Low- dose thyroid hormone may be added to existing antidepressants to treat persistent depression symptoms in people who have tried multiple courses of medication. Limited evidence suggests stimulants, such as amphetamine and modafinil, may be effective in the short term, or as adjuvant therapy. Also, it is suggested that folate supplements may have a role in depression management. There is tentative evidence for benefit from testosterone in males. Electroconvulsive therapy. Electroconvulsive therapy( ECT) is a standard psychiatric treatment in which seizures are electrically induced in a person with depression to provide relief from psychiatric illnesses. ECT is used with informed consent as a last line of intervention for major depressive disorder. A round of ECT is effective for about 50% of people with treatment- resistant major depressive disorder, whether it is unipolar or bipolar. Follow- up treatment is still poorly studied, but about half of people who respond relapse within twelve months. Aside from effects in the brain, the general physical risks of ECT are similar to those of brief general anesthesia. Immediately following treatment, the most common adverse effects are confusion and memory loss. ECT is considered one of the least harmful treatment options available for severely depressed | pregnant women. A usual course |
of ECT involves multiple administrations, typically given two or three times per week, until the person is no longer suffering symptoms. ECT is administered under anesthesia with a muscle relaxant. Electroconvulsive therapy can differ in its application in three ways: electrode placement, frequency of treatments, and the electrical waveform of the stimulus. These three forms of application have significant differences in both adverse side effects and symptom remission. After treatment, drug therapy is usually continued, and some people receive maintenance ECT. ECT appears to work in the short term via an anticonvulsant effect mostly in the frontal lobes, and longer term via neurotrophic effects primarily in the medial temporal lobe. Transcranial magnetic stimulation. Transcranial magnetic stimulation( TMS) or deep transcranial magnetic stimulation is a noninvasive method used to stimulate small regions of the brain. TMS was approved by the FDA for treatment- resistant major depressive disorder( trMDD) in 2008 and as of 2014 evidence supports that it is probably effective. The American Psychiatric Association the Canadian Network for Mood and Anxiety Disorders, and the Royal Australia and New Zealand College of Psychiatrists have endorsed TMS for trMDD. Transcranial direct current stimulation. Transcranial direct current stimulation( tDCS) is another noninvasive method used to stimulate small regions of the brain with the help of a weak electric current. Increasing evidence has been gathered for its efficiency as a depression treatment. A meta- analysis was published in 2020 summarising results across nine studies( 572 participants) concluded that active tDCS was significantly superior to sham for response( 30. 9% vs. 18. 9%, respectively), remission( 19. 9% vs. 11. 7%) and depression improvement. According to a 2016 meta analysis, 34% of people treated with tDCS showed at least 50% symptom reduction compared to 19% sham- treated across 6 randomised controlled trials. Light therapy. Bright light therapy reduces depression symptom severity, with benefit for both seasonal affective disorder and for nonseasonal depression, and an effect similar to those for conventional antidepressants. For nonseasonal depression, adding light therapy to the standard antidepressant treatment was not effective. For nonseasonal depression, where light was used mostly in combination with antidepressants or wake therapy, a moderate effect was found, with response better than control treatment in high- quality studies, in studies that applied morning light treatment, and with people who respond to total or partial sleep deprivation. Both analyses noted poor quality, short duration, and small size of most of the reviewed studies. Other. There is a small amount of evidence that skipping a night' s sleep may improve depressive symptoms, with the effects usually showing up within a day. This effect is usually temporary. Besides sleepiness, this method can cause a side effect of mania or hypomania. There is insufficient evidence for Reiki and dance movement therapy in depression. As of 2019 cannabis is specifically not recommended as a treatment. Prognosis. Studies have shown that 80% of those suffering from their first major depressive episode will have at least one more depression during their life, with a lifetime average of 4 episodes. Other general population studies indicate that around half those | who have an episode recover( |
whether treated or not) and remain well, while the other half will have at least one more, and around 15% of those experience chronic recurrence. Studies recruiting from selective inpatient sources suggest lower recovery and higher chronicity, while studies of mostly outpatients show that nearly all recover, with a median episode duration of 11 months. Around 90% of those with severe or psychotic depression, most of whom also meet criteria for other mental disorders, experience recurrence. Cases when outcome is poor are associated with inappropriate treatment, severe initial symptoms including psychosis, early age of onset, previous episodes, incomplete recovery after one year of treatment, pre- existing severe mental or medical disorder, and family dysfunction. A high proportion of people who experience full symptomatic remission still have at least one not fully resolved symptom after treatment. Recurrence or chronicity is more likely if symptoms have not fully resolved with treatment. Current guidelines recommend continuing antidepressants for four to six months after remission to prevent relapse. Evidence from many randomized controlled trials indicate continuing antidepressant medications after recovery can reduce the chance of relapse by 70%( 41% on placebo vs. 18% on antidepressant). The preventive effect probably lasts for at least the first 36 months of use. Major depressive episodes often resolve over time whether or not they are treated. Outpatients on a waiting list show a 10– 15% reduction in symptoms within a few months, with approximately 20% no longer meeting the full criteria for a depressive disorder. The median duration of an episode has been estimated to be 23 weeks, with the highest rate of recovery in the first three months. According to a 2013 review, 23% of untreated adults suffering from mild to moderate depression will remit within 3 months, 32% within 6 months and 53% within 12 months. Ability to work. Depression may affect people' s ability to work. The combination of usual clinical care and support with return to work( like working less hours or changing tasks) probably reduces sick leave by 15%, and leads to fewer depressive symptoms and improved work capacity, reducing sick leave by an annual average of 25 days per year. Helping depressed people return to work without a connection to clinical care has not been shown to have an effect on sick leave days. Additional psychological interventions( such as online cognitive behavioral therapy) leads to fewer sick days compared to standard management only. Streamlining care or adding specific providers for depression care may help to reduce sick leave. Life expectancy and the risk of suicide. Depressed individuals have a shorter life expectancy than those without depression, in part because people who are depressed are at risk of dying of suicide. Up to 60% of people who die of suicide have a mood disorder such as major depression, and the risk is especially high if a person has a marked sense of hopelessness or has both depression and borderline personality disorder. About 2– 8% of adults with major depression die by suicide, and about 50% of people who die by suicide had depression or another | mood disorder. The lifetime risk |
of suicide associated with a diagnosis of major depression in the US is estimated at 3. 4%, which averages two highly disparate figures of almost 7% for men and 1% for women( although suicide attempts are more frequent in women). The estimate is substantially lower than a previously accepted figure of 15%, which had been derived from older studies of people who were hospitalized. Depressed people have a higher rate of dying from other causes. There is a 1. 5- to 2- fold increased risk of cardiovascular disease, independent of other known risk factors, and is itself linked directly or indirectly to risk factors such as smoking and obesity. People with major depression are less likely to follow medical recommendations for treating and preventing cardiovascular disorders, further increasing their risk of medical complications. Cardiologists may not recognize underlying depression that complicates a cardiovascular problem under their care. Epidemiology. Major depressive disorder affected approximately 163 million people in 2017( 2% of the global population). The percentage of people who are affected at one point in their life varies from 7% in Japan to 21% in France. In most countries the number of people who have depression during their lives falls within an 8– 18% range. In North America, the probability of having a major depressive episode within a year- long period is 3– 5% for males and 8– 10% for females. Major depression is about twice as common in women as in men, although it is unclear why this is so, and whether factors unaccounted for are contributing to this. The relative increase in occurrence is related to pubertal development rather than chronological age, reaches adult ratios between the ages of 15 and 18, and appears associated with psychosocial more than hormonal factors. As of 2017, depression is the third most common worldwide cause of disability among both sexes, following low back pain and headache. People are most likely to develop their first depressive episode between the ages of 30 and 40, and there is a second, smaller peak of incidence between ages 50 and 60. The risk of major depression is increased with neurological conditions such as stroke, Parkinson' s disease, or multiple sclerosis, and during the first year after childbirth. It is also more common after cardiovascular illnesses, and is related more to those with a poor cardiac disease outcome than to a better one. Studies conflict on the prevalence of depression in the elderly, but most data suggest there is a reduction in this age group. Depressive disorders are more common in urban populations than in rural ones and the prevalence is increased in groups with poorer socioeconomic factors, e. g., homelessness. Major depression is currently the leading cause of disease burden in North America and other high- income countries, and the fourth- leading cause worldwide. In the year 2030, it is predicted to be the second- leading cause of disease burden worldwide after HIV, according to the WHO. Delay or failure in seeking treatment after relapse and the failure of health professionals to provide treatment are two barriers to | reducing disability. Comorbidity. Major depression |
frequently co- occurs with other psychiatric problems. The 1990– 92" National Comorbidity Survey"( US) reports that half of those with major depression also have lifetime anxiety and its associated disorders, such as generalized anxiety disorder. Anxiety symptoms can have a major impact on the course of a depressive illness, with delayed recovery, increased risk of relapse, greater disability and increased suicidal behavior. Depressed people have increased rates of alcohol and substance use, particularly dependence, and around a third of individuals diagnosed with attention deficit hyperactivity disorder( ADHD) develop comorbid depression. Post- traumatic stress disorder and depression often co- occur. Depression may also coexist with ADHD, complicating the diagnosis and treatment of both. Depression is also frequently comorbid with alcohol use disorder and personality disorders. Depression can also be exacerbated during particular months( usually winter) in those with seasonal affective disorder. While overuse of digital media has been associated with depressive symptoms, using digital media may also improve mood in some situations. Depression and pain often co- occur. One or more pain symptoms are present in 65% of people who have depression, and anywhere from 5 to 85% of people who are experiencing pain will be suffering from depression, depending on the setting— a lower prevalence in general practice, and higher in specialty clinics. Depression is often underrecognized, and therefore undertreated, in patients presenting with pain. Depression often coexists with physical disorders common among the elderly, such as stroke, other cardiovascular diseases, Parkinson' s disease, and chronic obstructive pulmonary disease. History. The Ancient Greek physician Hippocrates described a syndrome of melancholia as a distinct disease with particular mental and physical symptoms; he characterized all" fears and despondencies, if they last a long time" as being symptomatic of the ailment. It was a similar but far broader concept than today' s depression; prominence was given to a clustering of the symptoms of sadness, dejection, and despondency, and often fear, anger, delusions and obsessions were included. The term" depression" itself was derived from the Latin verb" deprimere"," to press down".Fromthe14th century," to depress" meant to subjugate or to bring down in spirits. It was used in 1665 in English author Richard Baker' s" Chronicle" to refer to someone having" a great depression of spirit", and by English author Samuel Johnson in a similar sense in 1753. The term also came into use in physiology and economics. An early usage referring to a psychiatric symptom was by French psychiatrist Louis Delasiauve in 1856,andbythe1860s it was appearing in medical dictionaries to refer to a physiological and metaphorical lowering of emotional function. Since Aristotle, melancholia had been associated with men of learning and intellectual brilliance, a hazard of contemplation and creativity. The newer concept abandoned these associations andthroughthe19th century, became more associated with women. Although" melancholia" remained the dominant diagnostic term," depression" gained increasing currency in medical treatises and was a synonym by the end of the century; German psychiatrist Emil Kraepelin may have been the first to use it as the overarching term, referring to different kinds of melancholia as" depressive states". Freud likened the state of | melancholia to mourning in his |
1917 paper" Mourning and Melancholia". He theorized that objective loss, such as the loss of a valued relationship through death or a romantic break- up, results in subjective loss as well; the depressed individual has identified with the object of affection through an unconscious, narcissistic process called the" libidinal cathexis" of the ego. Such loss results in severe melancholic symptoms more profound than mourning; not only is the outside world viewed negatively but the ego itself is compromised. The person' s decline of self- perception is revealed in his belief of his own blame, inferiority, and unworthiness. He also emphasized early life experiences as a predisposing factor. Adolf Meyer put forward a mixed social and biological framework emphasizing" reactions" in the context of an individual' s life, and argued that the term" depression" should be used instead of" melancholia". The first version of the DSM( DSM- I, 1952) contained" depressive reaction" and the DSM- II( 1968)" depressive neurosis", defined as an excessive reaction to internal conflict or an identifiable event, and also included a depressive type of manic- depressive psychosis within Major affective disorders. In the mid-20th century, researchers theorized that depression was caused by a chemical imbalance in neurotransmitters in the brain,atheorybasedonobservationsmadeinthe1950s of the effects of reserpine and isoniazid in altering monoamine neurotransmitter levels and affecting depressive symptoms. The chemical imbalance theory has never been proven. The term" unipolar"( along with the related term" bipolar") was coined by the neurologist and psychiatrist Karl Kleist, and subsequently used by his disciples Edda Neele and Karl Leonhard. The term" Major depressive disorder" was introduced by a group of US clinicians in the mid-1970s as part of proposals for diagnostic criteria based on patterns of symptoms( called the" Research Diagnostic Criteria", building on earlier Feighner Criteria), and was incorporated into the DSM- III in 1980. The American Psychiatric Association added" major depressive disorder" to the" Diagnostic and Statistical Manual of Mental Disorders"( DSM- III), as a split of the previous depressive neurosis in the DSM- II, which also encompassed the conditions now known as dysthymia and adjustment disorder with depressed mood. To maintain consistency the ICD- 10 used the same criteria, with only minor alterations, but using the DSM diagnostic threshold to mark a" mild depressive episode", adding higher threshold categories for moderate and severe episodes. The ancient idea of" melancholia" still survives in the notion of a melancholic subtype. The new definitions of depression were widely accepted, albeit with some conflicting findings and views. There have been some continued empirically based arguments for a return to the diagnosis of melancholia. There has been some criticism of the expansion of coverage of the diagnosis, related to the development and promotion of antidepressants andthebiologicalmodelsincethelate1950s. Society and culture. Terminology. The term" depression" is used in a number of different ways. It is often used to mean this syndrome but may refer to other mood disorders or simply to a low mood. People' s conceptualizations of depression vary widely, both within and among cultures." Because of the lack of scientific certainty," one commentator has observed," the debate | over depression turns on questions |
of language. What we call it—' disease,'' disorder,'' state of mind'— affects how we view, diagnose, and treat it." There are cultural differences in the extent to which serious depression is considered an illness requiring personal professional treatment, or is an indicator of something else, such as the need to address social or moral problems, the result of biological imbalances, or a reflection of individual differences in the understanding of distress that may reinforce feelings of powerlessness, and emotional struggle. The diagnosis is less common in some countries, such as China. It has been argued that the Chinese traditionally deny or somatize emotional depression(althoughsincetheearly1980s, the Chinese denial of depression may have modified). Alternatively, it may be that Western cultures reframe and elevate some expressions of human distress to disorder status. Australian professor Gordon Parker and others have argued that the Western concept of depression" medicalizes" sadness or misery. Similarly, Hungarian- American psychiatrist Thomas Szasz and others argue that depression is a metaphorical illness that is inappropriately regarded as an actual disease. There has also been concern that the DSM, as well as the field of descriptive psychiatry that employs it, tends to reify abstract phenomena such as depression, which may in fact be social constructs. American archetypal psychologist James Hillman writes that depression can be healthy for the soul, insofar as" it brings refuge, limitation, focus, gravity, weight, and humble powerlessness." Hillman argues that therapeutic attempts to eliminate depression echo the Christian theme of resurrection, but have the unfortunate effect of demonizing a soulful state of being. Stigma. Historical figures were often reluctant to discuss or seek treatment for depression due to social stigma about the condition, or due to ignorance of diagnosis or treatments. Nevertheless, analysis or interpretation of letters, journals, artwork, writings, or statements of family and friends of some historical personalities has led to the presumption that they may have had some form of depression. People who may have had depression include English author Mary Shelley, American- British writer Henry James, and American president Abraham Lincoln. Some well- known contemporary people with possible depression include Canadian songwriter Leonard Cohen and American playwright and novelist Tennessee Williams. Some pioneering psychologists, such as Americans William James and John B. Watson, dealt with their own depression. There has been a continuing discussion of whether neurological disorders and mood disorders may be linked to creativity, a discussion that goes back to Aristotelian times. British literature gives many examples of reflections on depression. English philosopher John Stuart Mill experienced a several- months- long period of what he called" a dull state of nerves", when one is" unsusceptible to enjoyment or pleasurable excitement; one of those moods when what is pleasure at other times, becomes insipid or indifferent". He quoted English poet Samuel Taylor Coleridge' s" Dejection" as a perfect description of his case:" A grief without a pang, void, dark and drear,/ A drowsy, stifled, unimpassioned grief,/ Which finds no natural outlet or relief/ In word, or sigh, or tear." English writer Samuel Johnson used the term" the black dog" in the1780s to describe | his own depression, and it |
was subsequently popularized by depression sufferer former British Prime Minister Sir Winston Churchill. Social stigma of major depression is widespread, and contact with mental health services reduces this only slightly. Public opinions on treatment differ markedly to those of health professionals; alternative treatments are held to be more helpful than pharmacological ones, which are viewed poorly. In the UK, the Royal College of Psychiatrists and the Royal College of General Practitioners conducted a joint Five- year Defeat Depression campaign to educate and reduce stigma from 1992 to 1996; a MORI study conducted afterwards showed a small positive change in public attitudes to depression and treatment. Elderly. Depression is especially common among those over 65 years of age and increases in frequency beyond this age. In addition, the risk of depression increases in relation to the frailty of the individual. Depression is one of the most important factors which negatively impact quality of life in adults, as well as the elderly. Both symptoms and treatment among the elderly differ from those of the rest of the population. As with many other diseases, it is common among the elderly not to present with classical depressive symptoms. Diagnosis and treatment is further complicated in that the elderly are often simultaneously treated with a number of other drugs, and often have other concurrent diseases. Treatment differs in that studies of SSRIs have shown lesser and often inadequate effects among the elderly, while other drugs, such as duloxetine( a serotonin- norepinephrine reuptake inhibitor), with more clear effects have adverse effects, such as dizziness, dryness of the mouth, diarrhea and constipation, which can be especially difficult to handle among the elderly. Problem solving therapy was, as of 2015, the only psychological therapy with proven effect, and can be likened to a simpler form of cognitive behavioral therapy. However, elderly with depression are seldom offered any psychological treatment, and the evidence proving other treatments effective is incomplete. ECT has been used in the elderly, and register- studies suggest it is effective, although less so as compared to the rest of the population. The risks involved with treatment of depression among the elderly as opposed to benefits are not entirely clear. Research. MRI scans of people with depression have revealed a number of differences in brain structure compared to those who are not depressed. Meta- analyses of neuroimaging studies in major depression reported that, compared to controls, people who are depressed had increased volume of the lateral ventricles and adrenal gland and smaller volumes of the basal ganglia, thalamus, hippocampus, and frontal lobe( including the orbitofrontal cortex and gyrus rectus). Hyperintensities have been associated with people with a late age of onset, and have led to the development of the theory of vascular depression. Trials are looking at the effects of botulinum toxins on depression. The idea is that the drug is used to make the person look less frowning and that this stops the negative facial feedback from the face. In 2018– 2019, the US Food and Drug Administration( FDA) granted Breakthrough therapy designation to Compass Pathways and, separately, | Usona Institute. Compass is a |
for- profit company studying psilocybin for treatment- resistant depression; Usona is a non- profit organization studying psilocybin for major depressive disorder more broadly. Animal models. Models of depression in animals for the purpose of study include iatrogenic depression models( such as drug- induced), forced swim tests, tail suspension test, and learned helplessness models. Criteria frequently used to assess depression in animals include expression of despair, neurovegetative changes, and anhedonia, as many other criteria for depression are untestable in animals, such as guilt and suicidality. Diana is a goddess in Roman and Hellenistic religion, primarily considered a patroness of the countryside, hunters, crossroads, and the Moon. She is equated with the Greek goddess Artemis, and absorbed much of Artemis' mythology early in Roman history, including a birth on the island of Delos to parents Jupiter and Latona, and a twin brother, Apollo, though she had an independent origin in Italy. Diana is considered a virgin goddess and protector of childbirth. Historically, Diana made up a triad with two other Roman deities: Egeria the water nymph, her servant and assistant midwife; and Virbius, the woodland god. Diana is revered in modern neopagan religions including Roman neopaganism, Stregheria, and Wicca. In the ancient, medieval, and modern periods, Diana has been considered a triple deity, merged with a goddess of the moon( Luna/ Selene) and the underworld( usually Hecate). Etymology. The name" Dīāna" probably derives from Latin" dīus"(' godly'), ultimately from Proto- Italic*" divios"(" diwios"), meaning' divine, heavenly'. It stems from Proto- Indo- European"* diwyós"(' divine, heavenly'), formed with the root"* dyew-"(' daylight sky') attached the thematic suffix-" yós". Cognates appear in Myceanean Greek" di- wi- ja", in Ancient Greek" dîos"( δῖος;' belonging to heaven, godlike'), or in Sanskrit" divyá"(' heavenly' or' celestial'). The ancient Latin writers Varro and Cicero considered the etymology of Dīāna as allied to that of" dies" and connected to the shine of the Moon, noting that one of her titles is Diana Lucifera(" light- bearer").... people regard Diana and the moon as one and the same.... the moon"( luna)" is so called from the verb to shine"( lucere)". Lucina is identified with it, which is why in our country they invoke Juno Lucina in childbirth, just as the Greeks call on Diana the Light- bearer. Diana also has the name" Omnivaga"(" wandering everywhere"), not because of her hunting but because she is numbered as one of the seven planets; her name Diana derives from the fact that she turns darkness into daylight"( dies)". She is invoked at childbirth because children are born occasionally after seven, or usually after nine, lunar revolutions... Description. As a goddess of the countryside. The persona of Diana is complex, and contains a number of archaic features. Diana was originally considered to be a goddess of the wilderness and of the hunt, a central sport in both Roman and Greek culture. Early Roman inscriptions to Diana celebrated her primarily as a huntress and patron of hunters. Later, in the Hellenistic period, Diana came to be equally or more revered as a goddess not of the wild woodland | but of the" tame" countryside, |
or" villa rustica", the idealization of which was common in Greek thought and poetry. This dual role as goddess of both civilization and the wild, and therefore the civilized countryside, first applied to the Greek goddess Artemis( for example,inthe3rd century BCE poetry of Anacreon).Bythe3rd century CE, after Greek influence had a profound impact on Roman religion, Diana had been almost fully combined with Artemis and took on many of her attributes, both in her spiritual domains and in the description of her appearance. The Roman poet Nemesianus wrote a typical description of Diana: She carried a bow and a quiver full of golden arrows, wore a golden cloak, purple half- boots, and a belt with a jeweled buckle to hold her tunic together, and wore her hair gathered in a ribbon.Bythe5th century CE, almost a millennia after her cult' s entry into Rome, the philosopher Proclus could still characterize Diana as" the inspective guardian of every thing rural,[ who] represses every thing rustic and uncultivated." As a triple goddess. Diana was often considered an aspect of a triple goddess, known as" Diana triformis": Diana, Luna, and Hecate. According to historian C. M. Green," these were neither different goddesses nor an amalgamation of different goddesses. They were Diana... Diana as huntress, Diana as the moon, Diana of the underworld." At her sacred grove on the shores of Lake Nemi,Dianawasveneratedasatriplegoddessbeginninginthelate6th century BCE. Andreas Alföldi interpreted an image on a late Republican coin as the Latin Diana" conceived as a threefold unity of the divine huntress, the Moon goddess and the goddess of the nether world, Hekate". This coin, minted by P. Accoleius Lariscolus in 43 BCE, has been acknowledged as representing an archaic statue of Diana Nemorensis. It represents Artemis with the bow at one extremity, Luna- Selene with flowers at the other and a central deity not immediately identifiable, all united by a horizontal bar. Theiconographicalanalysisallowsthedatingofthisimagetothe6th century at which time there are Etruscan models. The coin shows that the triple goddess cult image still stood in the" lucus" of Nemi in 43 BCE. Lake Nemi was called" Triviae lacus" by Virgil(" Aeneid" 7. 516), while Horace called Diana" montium custos nemoremque virgo"(" keeper of the mountains and virgin of Nemi") and" diva triformis"(" three- form goddess"). Two heads found in the sanctuary and the Roman theatre at Nemi, which have a hollow on their back, lend support to this interpretation of an archaic triple Diana. As goddess of crossroads and the underworld. The earliest epithet of Diana was" Trivia", and she was addressed with that title by Virgil, Catullus, and many others." Trivia" comes from the Latin" trivium"," triple way", and refers to Diana' s guardianship over roadways, particularly Y- junctions or three- way crossroads. This role carried a somewhat dark and dangerous connotation, as it metaphorically pointed the way to the underworld.Inthe1st- century CE play" Medea", Seneca' s titular sorceress calls on Trivia to cast a magic spell. She evokes the triple goddess of Diana, Selene, and Hecate, and specifies that she requires the powers of the latter. The1st century poet Horace | similarly wrote of a magic |
incantation invoking the power of both Diana and Proserpina. The symbol of the crossroads is relevant to several aspects of Diana' s domain. It can symbolize the paths hunters may encounter in the forest, lit only by the full moon; this symbolizes making choices" in the dark" without the light of guidance. Diana' s role as a goddess of the underworld, or at least of ushering people between life and death, caused her early on to be conflated with Hecate( and occasionally also with Proserpina). However, her role as an underworld goddess appears to pre- date strong Greek influence( though the early Greek colony of Cumae had a cult of Hekate and certainly had contacts with the Latins). A theater in her sanctuary at Lake Nemi included a pit and tunnel that would have allowed actors to easily descend on one side of the stage and ascend on the other, indicating a connection between the phases of the moon and a descent by the moon goddess into the underworld. It is likely that her underworld aspect in her original Latin worship did not have a distinct name, like Luna was for her moon aspect. This is due to a seeming reluctance or taboo by the early Latins to name underworld deities, and the fact that they believed the underworld to be silent, precluding naming. Hekate, a Greek goddess also associated with the boundary between the earth and the underworld, became attached to Diana as a name for her underworld aspect following Greek influence. As goddess of childbirth. Diana was often considered to be a goddess associated with fertility and childbirth, and the protection of women during labor. This probably arose as an extension of her association with the moon, whose cycles were believed to parallel the menstrual cycle, and which was used to track the months during pregnancy. At her shrine in Aricia, worshipers left votive terracotta offerings for the goddess in the shapes of babies and wombs, and the temple there also offered care of pups and pregnant dogs. This care of infants also extended to the training of both young people and dogs, especially for hunting. In her role as a protector of childbirth, Diana was called" Diana Lucina" or even" Juno Lucina", because her domain overlapped with that of the goddess Juno. The title of Juno may also have had an independent origin as it applied to Diana, with the literal meaning of" helper"- Diana as" Juno Lucina" would be the" helper of childbirth". As a" frame god". According to a theory proposed by Georges Dumézil, Diana falls into a particular subset of celestial gods, referred to in histories of religion as" frame gods". Such gods, while keeping the original features of celestial divinities( i. e. transcendent heavenly power and abstention from direct rule in worldly matters), did not share the fate of other celestial gods in Indoeuropean religions- that of becoming" dei otiosi", or gods without practical purpose, since they did retain a particular sort of influence over the world and mankind. The celestial character of Diana is | reflected in her connection with |
inaccessibility, virginity, light, and her preference for dwelling on high mountains and in sacred woods. Diana, therefore, reflects the heavenly world in its sovereignty, supremacy, impassibility, and indifference towards such secular matters as the fates of mortals and states. At the same time, however, she is seen as active in ensuring the succession of kings and in the preservation of humankind through the protection of childbirth. These functions are apparent in the traditional institutions and cults related to the goddess: According to Dumezil, the forerunner of all" frame gods" is an Indian epic hero who was the image( avatar) of the Vedic god Dyaus. Having renounced the world, in his roles of father and king, he attained the status of an immortal being while retaining the duty of ensuring that his dynasty is preserved and that there is always a new king for each generation. The Scandinavian god Heimdallr performs an analogous function: he is born first and will die last. He too gives origin to kingship and the first king, bestowing on him regal prerogatives. Diana, although a female deity, has exactly the same functions, preserving mankind through childbirth and royal succession. F. H. Pairault, in her essay on Diana, qualified Dumézil' s theory as" impossible to verify". Mythology. Unlike the Greek gods, Roman gods were originally considered to be numina: divine powers of presence and will that did not necessarily have physical form. At the time Rome was founded, Diana and the other major Roman gods probably did not have much mythology per se, or any depictions in human form. The idea of gods as having anthropomorphic qualities and human- like personalities and actions developed later, under the influence of Greek and Etruscan religion.Bythe3rd century BCE, Diana is found listed among the twelve major gods of the Roman pantheon by the poet Ennius. Though the Capitoline Triad were the primary state gods of Rome, early Roman myth did not assign a strict hierarchy to the gods the way Greek mythology did, though the Greek hierarchy would eventually be adopted by Roman religion as well. Once Greek influence had caused Diana to be considered identical to the Greek goddess Artemis, Diana acquired Artemis' s physical description, attributes, and variants of her myths as well. Like Artemis, Diana is usually depicted in art wearing a women’ s chiton, shortened in the kolpos style to facilitate mobility during hunting, with a hunting bow and quiver, and often accompanied by hunting dogs.A1st- century BCE Roman coin( see above) depicted her with a unique, short hairstyle, and in triple form, with one form holding a bow and another holding a poppy. Family. When worship of Apollo was first introduced to Rome, Diana became conflated with Apollo' s sister Artemis as in the earlier Greek myths, and as such she became identified as the daughter of Apollo' s parents Latona and Jupiter. Though Diana was usually considered to be a virgin goddess like Artemis, later authors sometimes attributed consorts and children to her. According to Cicero and Ennius, Trivia( an epithet of Diana) and Caelus were | the parents of Janus, as |
well as of Saturn and Ops. According to Macrobius( who cited Nigidius Figulus and Cicero), Janus and Jana( Diana) are a pair of divinities, worshiped as the sun and moon. Janus was said to receive sacrifices before all the others because, through him, the way of access to the desired deity is made apparent. Myth of Actaeon. Diana' s mythology incorporated stories which were variants of earlier stories about Artemis. Possibly the most well- known of these is the myth of Actaeon. In Ovid' s version of this myth, part of his poem" Metamorphoses", he tells of a pool or grotto hidden in the wooded valley of Gargaphie. There, Diana, the goddess of the woods, would bathe and rest after a hunt. Actaeon, a young hunter, stumbled across the grotto and accidentally witnessed the goddess bathing without invitation. In retaliation, Diana splashed him with water from the pool, cursing him, and he transformed into a deer. His own hunting dogs caught his scent, and tore him apart. Ovid' s version of the myth of Actaeon differs from most earlier sources. Unlike earlier myths about Artemis, Actaeon is killed for an innocent mistake, glimpsing Diana bathing. An earlier variant of this myth, known as the Bath of Pallas, had the hunter intentionally spy on the bathing goddess Pallas( Athena), and earlier versions of the myth involving Artemis did not involve the bath at all. Worship in the classical period. Diana was an ancient goddess common to all Latin tribes. Therefore, many sanctuaries were dedicated to her in the lands inhabited by Latins. Her primary sanctuary was a woodland grove overlooking Lake Nemi, a body of water also known as" Diana' s Mirror", where she was worshiped as Diana Nemorensis, or" Diana of the Wood". In Rome, the cult of Diana may have been almost as old as the city itself. Varro mentions her in the list of deities to whom king Titus Tatius promised to build a shrine. His list included Luna and Diana Lucina as separate entities. Another testimony to the antiquity of her cult is to be found in the" lex regia" of King Tullus Hostilius that condemns those guilty of incest to the" sacratio" to Diana. She had a temple in Rome on the Aventine Hill, according to tradition dedicated by king Servius Tullius. Its location is remarkable as the Aventine is situated outside the pomerium, i. e. original territory of the city, in order to comply with the tradition that Diana was a goddess common to all Latins and not exclusively of the Romans. Being placed on the Aventine, and thus outside the" pomerium", meant that Diana' s cult essentially remained a" foreign" one, like that of Bacchus; she was never officially" transferred" to Rome as Juno was after the sack of Veii. Other known sanctuaries and temples to Diana include Colle di Corne near Tusculum, where she is referred to with the archaic Latin name of" deva Cornisca" and where existed a collegium of worshippers; at Évora, Portugal; Mount Algidus, also near Tusculum; at Lavinium; and at Tibur( | Tivoli), where she is referred |
to as" Diana Opifera Nemorensis". Diana was also worshiped at a sacred wood mentioned by Livy-" ad compitum Anagninum"( near Anagni), and on Mount Tifata in Campania. According to Plutarch, men and women alike were worshipers of Diana and were welcomed into all of her temples. The one exception seems to have been a temple on the Vicus Patricius, which men either did not enter due to tradition, or were not allowed to enter. Plutarch related a legend that a man had attempted to assault a woman worshiping in this temple and was killed by a pack of dogs( echoing the myth of Diana and Actaeon), which resulted in a superstition against men entering the temple. A feature common to nearly all of Diana' s temples and shrines by the second century AD was the hanging up of stag antlers. Plutarch noted that the only exception to this was the temple on the Aventine Hill, in which bull horns had been hung up instead. Plutarch explains this by way of reference to a legend surrounding the sacrifice of an impressive Sabine bull by King Servius at the founding of the Aventine temple. Sanctuary at Lake Nemi. Diana' s worship may have originated at an open- air sanctuary overlooking Lake Nemi in the Alban Hills near Aricia, where she was worshiped as Diana Nemorensis, or(" Diana of the Sylvan Glade"). According to legendary accounts, the sanctuary was founded by Orestes and Iphigenia after they fled from the Tauri. In this tradition, the Nemi sanctuary was supposedly built on the pattern of an earlier Temple of Artemis Tauropolos, and the first cult statue at Nemi was said to have been stolen from the Tauri and brought to Nemi by Orestes. Historical evidence suggeststhatworshipofDianaatNemiflourishedfromatleastthe6thcenturyBCEuntilthe2nd century CE. Her cult there was first attested in Latin literature by Cato the Elder, in a surviving quote by the late grammarian Priscian.Bythe4th century BCE, the simple shrine at Nemi had been joined by a temple complex. The sanctuary served an important political role as it was held in common by the Latin League. A festival to Diana, the Nemoralia, was held yearly at Nemi on the Ides of August( August 13– 15). Worshipers traveled to Nemi carrying torches and garlands, and once at the lake, they left pieces of thread tied to fences and tablets inscribed with prayers. Diana' s festival eventually became widely celebrated throughout Italy, which was unusual given the provincial nature of Diana' s cult. The poet Statius wrote of the festival: Statius describes the triple nature of the goddess by invoking heavenly( the stars), earthly( the grove itself) and underworld( Hecate) imagery. He also suggests by the garlanding of the dogs and polishing of the spears that no hunting was allowed during the festival. Legend has it that Diana' s high priest at Nemi, known as the Rex Nemorensis, was always an escaped slave who could only obtain the position by defeating his predecessor in a fight to the death. Sir James George Frazer wrote of this sacred grove in" The Golden Bough", basing his | interpretation on brief remarks in |
Strabo( 5. 3. 12), Pausanias( 2, 27. 24) and Servius' commentary on the" Aeneid"( 6. 136). The legend tells of a tree that stood in the center of the grove and was heavily guarded. No one was allowed to break off its limbs, with the exception of a runaway slave, who was allowed, if he could, to break off one of the boughs. He was then in turn granted the privilege to engage the Rex Nemorensis, the current king and priest of Diana, in a fight to the death. If the slave prevailed, he became the next king for as long as he could defeat his challengers. However, Joseph Fontenrose criticised Frazer' s assumption that a rite of this sort actually occurred at the sanctuary, and no contemporary records exist that support the historical existence of the" Rex Nemorensis". Spread and conflation with Artemis. Rome hoped to unify into and control the Latin tribes around Nemi, so Diana' s worship was imported to Rome as a show of political solidarity. Diana soon afterwards became Hellenized, and combined with the Greek goddess Artemis," a process which culminated with the appearance of Diana beside Apollo[ the brother of Artemis] in the first" lectisternium" at Rome" in 399 BCE. The process of identification between the two goddesses probably began when artists who were commissioned to create new cult statues for Diana' s temples outside Nemi were struck by the similar attributes between Diana and the more familiar Artemis, and sculpted Diana in a manner inspired by previous depictions of Artemis. Sibyllene influence and trade with Massilia, where similar cult statues of Artemis existed, would have completed the process. According to Françoise Hélène Pairault' s study, historical and archaeological evidence point to the fact that the characteristics given to both Diana of the Aventine Hill and Diana Nemorensis were the product of the direct or indirect influence of the cult of Artemis, which was spread by the Phoceans among the Greek towns of Campania Cuma and Capua, who in turn had passed it overtotheEtruscansandtheLatinsbythe6thand5th centuries BCE. Evidence suggests that a confrontation occurred between two groups of Etruscans who fought for supremacy, those from Tarquinia, Vulci and Caere( allied with the Greeks of Capua) and those of Clusium. This is reflected in the legend of the coming of Orestes to Nemi and of the inhumation of his bones in the Roman Forum near the temple of Saturn. The cult introduced by Orestes at Nemi is apparently that of the Artemis Tauropolos. The literary amplification reveals a confused religious background: different versions of Artemis were conflated under the epithet. As far as Nemi' s Diana is concerned there are two different versions, by Strabo and Servius Honoratus. Strabo' s version looks to be the most authoritative as he had access to first- hand primary sources on the sanctuaries of Artemis, i. e. the priest of Artemis Artemidoros of Ephesus. The meaning of" Tauropolos" denotes an Asiatic goddess with lunar attributes, lady of the herds. The only possible" interpretatio graeca" of high antiquity concerning" Diana Nemorensis" could have been | the one based on this |
ancient aspect of a deity of light, master of wildlife." Tauropolos" is an ancient epithet attached to Artemis, Hecate, and even Athena. According to the legend Orestes founded Nemi together with Iphigenia. At Cuma the Sybil is the priestess of both Phoibos and Trivia. Hesiod and Stesichorus tell the story according to which after her death Iphigenia was divinised under the name of Hecate, a fact which would support the assumption that Artemis Tauropolos had a real ancient alliance with the heroine, who was her priestess in Taurid and her human paragon. This religious complex is in turn supported by the triple statue of Artemis- Hecate. In Rome, Diana was regarded with great reverence and was a patroness of lower- class citizens, called plebeians, as well as slaves, who could receive asylum in her temples. Georg Wissowa proposed that this might be because the first slaves of the Romans were Latins of the neighboring tribes. However, the Temple of Artemis at Ephesus had the same custom of the asylum. In Rome. Worship of Diana probably spread into the city of Rome beginning around 550 BCE, during her Hellenization and combination with the Greek goddess Artemis. Diana was first worshiped along with her brother and mother, Apollo and Latona, in their temple in the Campus Martius, and later in the Temple of Apollo Palatinus. The first major temple dedicated primarily to Diana in the vicinity of Rome was the Temple of Diana Aventina( Diana of the Aventine Hill). According to the Roman historian Livy,theconstructionofthistemplebeganinthe6th century BCE and was inspired by stories of the massive Temple of Artemis at Ephesus, which was said to have been built through the combined efforts of all the cities of Asia Minor. Legend has it that Servius Tullius was impressed with this act of massive political and economic cooperation, and convinced the cities of the Latin League to work with the Romans to build their own temple to the goddess. However, there is no compelling evidence for such an early construction of the temple, and it is morelikelythatitwasbuiltinthe3rd century BCE, following the influence of the temple at Nemi, and probably about the same time the first temples to Vertumnus( who was associated with Diana) were built in Rome( 264 BCE). The misconception that the Aventine Temple was inspired by the Ephesian Temple might originate in the fact that the cult images and statues used at the former were based heavily on those found in the latter. Whatever its initial construction date, records show that the Avantine Temple was rebuilt by Lucius Cornificius in 32 BCE. If it was stillinusebythe4th century CE, the Aventine temple would have been permanently closed during the persecution of pagans in the late Roman Empire. Today, a short street named the" Via del Tempio di Diana" and an associated plaza," Piazza del Tempio di Diana", commemorates the site of the temple. Part of its wall is located within one of the halls of the Apuleius restaurant. Later temple dedications often were based on the model for ritual formulas and regulations of the Temple of | Diana. Roman politicians built several |
minor temples to Diana elsewhere in Rome to secure public support. One of these was built in the Campus Martius in 187 BCE; no Imperial period records of this temple have been found, and it is possible it was one of the temples demolished around 55 BCE in order to build a theater. Diana also had a public temple on the Quirinal Hill, the sanctuary of Diana Planciana. It was dedicated by Plancius in 55 BCE, though it is unclear which Plancius. In their worship of Artemis, Greeks filled their temples with sculptures of the goddess created by well- known sculptors, and many were adapted for use in the worship of Diana by the Romans,beginningaroundthe2nd century BCE( the beginning of a period of strong Hellenistic influence on Roman religion). The earliest depictions of the Artemis of Ephesus are found on Ephesian coins from this period. By the Imperial period, small marble statues of the Ephesian Artemis were being produced in the Western region of the Mediterranean and were often bought by Roman patrons. The Romans obtained a large copy of an Ephesian Artemis statue for their temple on the Aventine Hill. Diana was usually depicted for educated Romans in her Greek guise. If she was shown accompanied by a deer, as in the" Diana of Versailles", this is because Diana was the patroness of hunting. The deer may also offer a covert reference to the myth of Acteon( or Actaeon), who saw her bathing naked. Diana transformed Acteon into a stag and set his own hunting dogs to kill him. At Mount Tifata. In Campania, Diana had a major temple at Mount Tifata, near Capua. She was worshiped there as" Diana Tifatina". This was one of the oldest sanctuaries in Campania. As a rural sanctuary, it included lands and estates that would have been worked by slaves following the Roman conquest of Campania, and records show that expansion and renovation projects at her temple were funded in part by other conquests by Roman military campaigns. The modern Christian church of Sant' Angelo in Formis was built on the ruins of the Tifata temple. Roman provinces. In the Roman provinces, Diana was widely worshiped alongside local deities. Over 100 inscriptions to Diana have been cataloged in the provinces, mainly from Gaul, Upper Germania, and Britannia. Diana was commonly invoked alongside another forest god, Silvanus, as well as other" mountain gods". In the provinces, she was occasionally conflated with local goddesses such as Abnoba, and was given high status, with" Augusta" and" regina"(" queen") being common epithets. Household worship. Diana was not only regarded as a goddess of the wilderness and the hunt, but was often worshiped as a patroness of families. She served a similar function to the hearth goddess Vesta, and was sometimes considered to be a member of the Penates, the deities most often invoked in household rituals. In this role, she was often given a name reflecting the tribe of family who worshiped her and asked for her protection. For example, in what is now Wiesbaden, Diana was worshiped as" | Diana Mattiaca" by the Mattiaci |
tribe. Other family- derived named attested in the ancient literature include" Diana Cariciana"," Diana Valeriana", and" Diana Plancia". As a house goddess, Diana often became reduced in stature compared to her official worship by the Roman state religion. In personal or family worship, Diana was brought to the level of other household spirits, and was believed to have a vested interest in the prosperity of the household and the continuation of the family. The Roman poet Horace regarded Diana as a household goddess in his" Odes", and had an altar dedicated to her in his villa where household worship could be conducted. In his poetry, Horace deliberately contrasted the kinds of grand, elevated hymns to Diana on behalf of the entire Roman state, the kind of worship that would have been typical at her Aventine temple, with a more personal form of devotion. Images of Diana and her associated myths have been found on sarcophagi of wealthy Romans. They often included scenes depicting sacrifices to the goddess, and on at least one example, the deceased man is shown joining Diana' s hunt. Theology. Since ancient times, philosophers and theologians have examined the nature of Diana in light of her worship traditions, attributes, mythology, and identification with other gods. Conflation with other goddesses. Diana was initially a hunting goddess and goddess of the local woodland at Nemi, but as her worship spread, she acquired attributes of other similar goddesses. As she became conflated with Artemis, she became a moon goddess, identified with the other lunar goddesses goddess Luna and Hekate. She also became the goddess of childbirth and ruled over the countryside. Catullus wrote a poem to Diana in which she has more than one alias: Latonia, Lucina, Juno, Trivia, Luna. Along with Mars, Diana was often venerated at games held in Roman amphitheaters, and some inscriptions from the Danubian provinces show that she was conflated with Nemesis in this role, as" Diana Nemesis". Outside of Italy, Diana had important centers of worship where she was syncretised with similar local deities in Gaul, Upper Germania, and Britannia. Diana was particularly important in the region in and around the Black Forest, where she was conflated with the local goddess Abnoba and worshiped as" Diana Abnoba". Some late antique sources went even further, syncretizing many local" great goddesses" into a single" Queen of Heaven". The Platonist philosopher Apuleius, writinginthelate2nd century, depicted the goddess declaring:" I come, Lucius, moved by your entreaties: I, mother of the universe, mistress of all the elements, first- born of the ages, highest of the gods, queen of the shades, first of those who dwell in heaven, representing in one shape all gods and goddesses. My will controls the shining heights of heaven, the health- giving sea- winds, and the mournful silences of hell; the entire world worships my single godhead in a thousand shapes, with divers rites, and under many a different name. The Phrygians, first- born of mankind, call me the Pessinuntian Mother of the gods; the native Athenians the Cecropian Minerva; the island- dwelling Cypriots Paphian Venus; the | archer Cretans Dictynnan Diana; the |
triple- tongued Sicilians Stygian Proserpine; the ancient Eleusinians Actaean Ceres; some call me Juno, some Bellona, others Hecate, others Rhamnusia; but both races of Ethiopians, those on whom the rising and those on whom the setting sun shines, and the Egyptians who excel in ancient learning, honour me with the worship which is truly mine and call me by my true name: Queen Isis." Later poets and historians looked to Diana' s identity as a triple goddess to merge her with triads heavenly, earthly, and underworld( cthonic) goddesses. Maurus Servius Honoratus said that the same goddess was called Luna in heaven, Diana on earth, and Proserpina in hell. Michael Drayton praises the Triple Diana in poem" The Man in the Moone"( 1606):" So these great three most powerful of the rest, Phoebe, Diana, Hecate, do tell. Her sovereignty in Heaven, in Earth and Hell". In Platonism. Based on the earlier writings of Plato, the Neoplatonist philosophers of late antiquity united the various major gods of Hellenic tradition into a series of monads containing within them triads, with some creating the world, some animating it or bringing it to life, and others harmonizing it. Within this system, Proclus considered Diana to be one of the primary animating, or life- giving, deities. Proclus, citing Orphic tradition, concludes that Diana" presides over all the generation in nature, and is the midwife of physical productive principles" and that she" extends these genitals, distributing as far as to subterranean natures the prolific power of[ Bacchus]." Specifically, Proclus considered the life- generating principle of the highest order, within the Intellectual realm, to be Rhea, whom he identified with Ceres. Within her divinity was produced the cause of the basic principle of life. Projecting this principle into the lower, Hypercosmic realm of reality generated a lower monad, Kore, who could therefore be understood as Ceres'" daughter". Kore embodied the" maidenly" principle of generation that, more importantly, included a principle of division- where Demeter generates life indiscriminately, Kore distributes it individually. This division results in another triad or trinity, known as the Maidenly trinity, within the monad of Kore: namely, Diana, Proserpine, and Minerva, through whom individual living beings are given life and perfected. Specifically, according to a commentary by scholar Spyridon Rangos, Diana( equated with Hecate) gives existence, Proserpine( equated with" Soul") gives form, and Minerva( equated with" Virtue") gives intellect. In his commentary on Proclus,the19th century Platonist scholar Thomas Taylor expanded upon the theology of the classical philosophers, further interpreting the nature and roles of the gods in light of the whole body of Neoplatonist philosophy. He cites Plato in giving a three- form aspect to her central characteristic of virginity: the undefiled, the mundane, and the anagogic. Through the first form, Diana is regarded as a" lover of virginity". Through the second, she is the guardian of virtue. Through the third, she is considered to" hate the impulses arising from generation." Through the principle of the undefiled, Taylor suggests that she is given supremacy in Proclus' triad of life- giving or animating deities, and in this role | the theurgists called her Hekate. |
In this role, Diana is granted undefiled power(" Amilieti") from the other gods. This generative power does not proceed forth from the goddess( according to a statement by the Oracle of Delphi) but rather resides with her, giving her unparalleled virtue, and in this way she can be said to embody virginity. Later commentators on Proclus have clarified that the virginity of Diana is not an absence of sexual drive, but a renunciation of sexuality. Diana embodies virginity because she generates but precedes active fertility( within Neoplatonism, an important maxim is that" every productive cause is superior to the nature of the produced effect"). Using the ancient Neoplatonists as a basis, Taylor also commented on the triadic nature of Diana and related goddesses, and the ways in which they subsist within one another, partaking unevenly in each other' s powers and attributes. For example, Kore is said to embody both Diana/ Hecate and Minerva, who create the virtuous or virgin power within her, but also Proserpine( her sole traditional identification), through whom the generative power of the Kore as a whole is able to proceed forth into the world, where it joins with the demiurge to produce further deities, including Bacchus and" nine azure- eyed, flower- producing daughters". Proclus also included Artemis/ Diana in a second triad of deities, along with Ceres and Juno. According to Proclus: Proclus pointed to the conflict between Hera and Artemis in the" Illiad" as a representation of the two kinds of human souls. Where Hera creates the higher, more cultured, or" worthy" souls, Artemis brings light to and perfects the" less worthy" or less rational. As explained by Ragnos( 2000)," The aspect of reality which Artemis and Hera share, and because of which they engage in a symbolic conflict, is the engendering of life." Hera elevates rational living beings up to intellectual rational existence, whereas Artemis' s power pertains to human life as far as its physical existence as a living thing." Artemis deals with the most elementary forms of life or the most elementary part of all life, whereas Hera operates in the most elevated forms of life or the most elevated part of all life. Worship in Post Roman Europe. Sermons and other religious documents have provided evidence for the worship of Diana during the Middle Ages. Though few details have been recorded, enough references to Diana worship during the early Christian period exist to give some indication that it may have been relatively widespread among remote and rural communities throughout Europe, and that such beliefs persisted into the Merovingian period. References to contemporary Diana worshipexistfromthe6th century on the Iberian peninsula and what is now southern France, though more detailed accounts of Dianic cults were given for the Low Countries, and southern Belgium in particular. Many of these were probably local goddesses, and wood nymphs or dryads, which had been conflated with Diana by Christian writers Latinizing local names and traditions. In the Low Countries. The6th century bishop Gregory of Tours reported meeting with a deacon named Vulfilaic( also known as Saint Wulflaicus or | Walfroy the Stylite), who founded |
a hermitage on a hill in what is now Margut, France. On the same hill, he found" an image of Diana which the unbelieving people worshiped as a god." According to Gregory' s report, worshipers would also sing chants in Diana' s honor as they drank and feasted. Vulfilaic destroyed a number of smaller pagan statues in the area, but the statue of Diana was too large. After converting some of the local population to Christianity, Vulfilaic and a group of local residents attempted to pull the large statue down the mountain in order to destroy it, but failed, as it was too large to be moved. In Vulfilaic' s account, after praying for a miracle, he was then able to single- handedly pull down the statue, at which point he and his group smashed it to dust with their hammers. According to Vulfilaic, this incident was quickly followed by an outbreak of pimples or sores that covered his entire body, which he attributed to demonic activity and similarly cured via what he described as a miracle. Vulfilaic would later found a church on the site, which is today known as Mont Saint- Walfroy. Additional evidence for surviving pagan practices in the Low Countries region comes from the" Vita Eligii", or" Life of Saint Eligius",writtenbyAudoininthe7th century. Audoin drew together the familiar admonitions of Eligius to the people of Flanders. In his sermons, he denounced" pagan customs" that the people continued to follow. In particular, he denounced several Roman gods and goddesses alongside Druidic mythological beliefs and objects:" I denounce and contest, that you shall observe no sacrilegious pagan customs. For no cause or infirmity should you consult magicians, diviners, sorcerers or incantators... Do not observe auguries... No influence attaches to the first work of the day or the[ phase of the] moon....[ Do not] make vetulas, little deer or iotticos or set tables at night or exchange New Year gifts or supply superfluous drinks... No Christian... performs solestitia or dancing or leaping or diabolical chants. No Christian should presume to invoke the name of a demon, not Neptune or Orcus or Diana or Minerva or Geniscus... No one should observe Jove' s day in idleness.... No Christian should make or render any devotion to the gods of the trivium, where three roads meet, to the fanes or the rocks, or springs or groves or corners. None should presume to hang any phylacteries from the neck of man nor beast... None should presume to make lustrations or incantations with herbs, or to pass cattle through a hollow tree or ditch... No woman should presume to hang amber from her neck or call upon Minerva or other ill- starred beings in their weaving or dyeing... None should call the sun or moon lord or swear by them... No one should tell fate or fortune or horoscopes by them as those do who believe that a person must be what he was born to be." Legends from medieval Belgium concern a natural spring which came to be known as the" Fons Remacli", a location which | may have been home to |
late- surviving worship of Diana. Remacle was a monk appointed by Eligius to head a monastery at Solignac, and he is reported to have encountered Diana worship in the area around the river Warche. The population in this region was said to have been involved in the worship of" Diana of the Ardennes"( a syncretism of Diana and the Celtic goddess Arduinna), with effigies and" stones of Diana" used as evidence of pagan practices. Remacle believed that demonic entities were present in the spring, and had caused it to run dry. He performed and exorcism of the water source, and installed a lead pipe, which allowed the water to flow again. The" Society of Diana". Diana is the only pagan goddess mentioned by name in the New Testament( only in some Bible versions of Acts 19; many other Bibles refer to her as Artemis instead). As a result, she became associated with many folk beliefs involving goddess- like supernatural figures that Catholic clergy wished to demonize. In the Middle Ages, legends of night- time processions of spirits led by a female figure are recorded in the church records of Northern Italy, western Germany, and southern France. The spirits were said to enter houses and consume food which then miraculously re- appeared. They would sing and dance, and dispense advise regarding healing herbs and the whereabouts of lost objects. If the house was in good order, they would bring fertility and plenty. If not, they would bring curses to the family. Some women reported participating in these processions while their bodies still lay in bed. Historian Carlo Ginzburg has referred to these legendary spirit gatherings as" The Society of Diana". Local clergy complained that women believed they were following Diana or Herodias, riding out on appointed nights to join the processions or carry out instructions from the goddess. The earliest reports of these legends appear in the writings of Regino of Prüm in the year 899, followed by many additional reports and variants of the legend in documents by Ratherius and others. By 1310, the names of the goddess figures attached to the legend were sometimes combined as Herodiana. It is likely that the clergy of this time used the identification of the procession' s leader as Diana or Herodias in order to fit an older folk belief into a Biblical framework, as both are featured and demonized in the New Testament. Herodias was often conflated with her daughter Salome in legend, which also holds that, upon being presented with the severed head of John the Baptist, she was blown into the air by wind from the saint' s mouth, through which she continued to wander for eternity. Diana was often conflated with Hecate, a goddess associated with the spirits of the dead and with witchcraft. These associations, and the fact that both figures are attested to in the Bible, made them a natural fit for the leader of the ghostly procession. Clergy used this identification to assert that the spirits were evil, and that the women who followed them were inspired by | demons. As was typical of |
this time period, though pagan beliefs and practices were near totally eliminated from Europe, the clergy and other authorities still treated paganism as a real threat, in part thanks to biblical influence; much of the Bible had been written when various forms of paganism were still active if not dominant, so medieval clergy applied the same kinds of warnings and admonitions for any non- standard folk beliefs and practices they encountered. Based on analysis of church documents and parishioner confessions, it is likely that the spirit identified by the Church as Diana or Herodias was called by names of pre- Christian figures like Holda( a Germanic goddess of the winter solstice), or with names referencing her bringing of prosperity, like the Latin Abundia( meaning" plenty"), Satia( meaning" full" or" plentiful") and the Italian Richella( meaning" rich"). Some of the local titles for her, such as" bonae res"( meaning" good things"), are similar to late classical titles for Hecate, like" bona dea". This might indicate a cultural mixture of medieval folk ideas with holdovers from earlier pagan belief systems. Whatever her true origin,bythe13th century, the leader of the legendary spirit procession had come to be firmly identified with Diana and Herodias through the influence of the Church. Modern development and folklore." The Golden Bough". In his wide- ranging, comparative study of mythology and religion," The Golden Bough", anthropologist James George Frazer drew on various lines of evidence to re- interpret the legendary rituals associated with Diana at Nemi, particularly that of the" rex Nemorensis". Frazer developed his ideas in relation to J. M. W. Turner' s painting, also titled" The Golden Bough", depicting a dream- like vision of the woodland lake of Nemi. According to Frazer, the" rex Nemorensis" or king at Nemi was the incarnation of a dying and reviving god, a solar deity who participated in a mystical marriage to a goddess. He died at the harvest and was reincarnated in the spring. Frazer claimed that this motif of death and rebirth is central to nearly all of the world' s religions and mythologies. In Frazer' s theory, Diana functioned as a goddess of fertility and childbirth, who, assisted by the sacred king, ritually returned life to the land in spring. The king in this scheme served not only as a high priest but as a god of the grove. Frazer identifies this figure with Virbius, of which little is known, but also with Jupiter via an association with sacred oak trees. Frazer argued furthermore that Jupiter and Juno were simply duplicate names of Jana and Janus; that is, Diana and Dianus, all of whom had identical functions and origins. Frazer' s speculatively reconstructed folklore of Diana' s origins and the nature of her cult at Nemi were not well received even by his contemporaries. Godfrey Lienhardt noted that even during Frazer' s lifetime, other anthropologists had" for the most part distanced themselves from his theories and opinions", and that the lasting influence of" The Golden Bough" and Frazer' s wider body of work" has been in the literary rather than | the academic world." Robert Ackerman |
wrote that, for anthropologists, Frazer is" an embarrassment" for being" the most famous of them all" and that most distance themselves from his work. While" The Golden Bough" achieved wide" popular appeal" and exerted a" disproportionate" influence" on so many[20th century] creative writers", Frazer' s ideas played" a much smaller part" in the history of academic social anthropology." The Gospel of the Witches". Folk legends like the Society of Diana, which linked the goddess to forbidden gatherings of women with spirits, may have influenced later works of folklore. One of these is Charles Godfrey Leland' s" Aradia, or the Gospel of the Witches", which prominently featured Diana at the center of an Italian witch- cult. In Leland' s interpretation of supposed Italian folk witchcraft, Diana is considered Queen of the Witches. In this belief system, Diana is said to have created the world of her own being having in herself the seeds of all creation yet to come. It was said that out of herself she divided the darkness and the light, keeping for herself the darkness of creation and creating her brother Lucifer. Diana was believed to have loved and ruled with her brother, and with him bore a daughter, Aradia( a name likely derived from Herodias), who leads and teaches the witches on earth. Leland' s claim that" Aradia" represented an authentic tradition from an underground witch- cult, which had secretly worshiped Diana since ancient times has been dismissed by most scholars of folklore, religion, and medieval history. After the 1921 publication of Margaret Murray' s" The Witch- cult in Western Europe", which hypothesized that the European witch trials were actually a persecution of a pagan religious survival, American sensationalist author Theda Kenyon' s 1929 book" Witches Still Live" connected Murray' s thesis with the witchcraft religion in" Aradia". Arguments against Murray' s thesis would eventually include arguments against Leland. Witchcraft scholar Jeffrey Russell devoted some of his 1980 book" A History of Witchcraft: Sorcerers, Heretics and Pagans" to arguing against the claims Leland presented in" Aradia". Historian Elliot Rose' s" A Razor for a Goat" dismissed" Aradia" as a collection of incantations unsuccessfully attempting to portray a religion. In his book" Triumph of the Moon", historian Ronald Hutton doubted not only of the existence of the religion that" Aradia" claimed to represent, and that the traditions Leland presented were unlike anything found in actual medieval literature, but also of the existence of Leland' s sources, arguing that it is more likely that Leland created the entire story than that Leland could be so easily" duped". Religious scholar Chas S. Clifton took exception to Hutton' s position, writing that it amounted to an accusation of" serious literary fraud" made by an" argument from absence". Building on the work of Frazer, Murray, and others,some20thand21st century authors have attempted to identify links between Diana and more localized deities. R. Lowe Thompson, for example, in his 2013 book" The History of the Devil", speculated that Diana may have been linked as an occasional" spouse" to the Gaulish horned god Cernunnos. Thompson suggested that | Diana in her role as |
wild goddess of the hunt would have made a fitting consort for Cernunnos in Western Europe, and further noted the link between Diana as Proserpina with Pluto, the Greek god associated with the riches of the earth who served a similar role to the Gaulish Cernunnos. Modern worship. Because Leland' s claims about an Italian witch- cult are questionable, the first verifiable worship of Diana in the modern age was probably begun by Wicca. The earliest known practitioners of Neopagan witchcraft were members of a tradition begun by Gerald Gardner. Published versions of the devotional materials used by Gardner' s group, dated to 1949, are heavily focused on the worship of Aradia, the daughter of Diana in Leland' s folklore. Diana herself was recognized as an aspect of a single" great goddess" in the tradition of Apuleius, as described in the Wiccan Charge of the Goddess( itself adapted from Leland' s text). Some later Wiccans, such as Scott Cunningham, would replace Aradia with Diana as the central focus of worship.Intheearly1960s, Victor Henry Anderson founded the Feri Tradition, a form of Wicca that draws from both Charles Leland' s folklore and the Gardnerian tradition. Anderson claimed that he had first been initiated into a witchcraft tradition as a child in 1926, and that he had been told the name of the goddess worshiped by witches was Tana. The name Tana originated in Leland' s" Aradia", where he claimed it was an old Etruscan name for Diana. The Feri Tradition founded by Anderson continues to recognize Tana/ Diana as an aspect of the Star Goddess related to the element of fire, and representing" the fiery womb that gives birth to and transforms all matter."( In" Aradia", Diana is also credited as the creatrix of the material world and Queen of Faeries). A few Wiccan traditions would elevate Diana to a more prominent position of worship, and there are two distinct modern branches of Wicca focused primarily on Diana. The first,foundedduringtheearly1970s in the United States by Morgan McFarland and Mark Roberts, has a feminist theology and only occasionally accepts male participants, and leadership is limited to female priestesses. McFarland Dianic Wiccans base their tradition primarily on the work of Robert Graves and his book" The White Goddess", and were inspired by references to the existence of medieval European" Dianic cults" in Margaret Murray' s book" The Witch- Cult in Western Europe". The second Dianic tradition, founded by Zsuzsanna Budapestinthemid1970s, is characterized by an exclusive focus on the feminine aspect of the divine, and as a result is exclusively female. This tradition combines elements from British Traditional Wicca, Italian folk- magic based on the work of Charles Leland, feminist values, and healing practices drawn from a variety of different cultures. A third Neopagan tradition heavily inspired by the worship of Diana through the lens of Italian folklore is Stregheria, founded inthe1980s. It centers around a pair of deities regarded as divine lovers, who are known by several variant names including Diana and Dianus, alternately given as Tana and Tanus or Jana and Janus( the later two | deity names were mentioned by |
James Frazer in" The Golden Bough" as later corruptions of Diana and Dianus, which themselves were alternate and possibly older names for Juno and Jupiter). The tradition was founded by author Raven Grimassi, and influenced by Italian folktales he was told by his mother. One such folktale describes the moon being impregnated by her lover the morning star, a parallel to Leland' s mythology of Diana and her lover Lucifer. Diana was also a subject of worship in certain Feraferian rites, particularly those surrounding the autumnal equinox, beginning in 1967. Legacy. In language. Both the Romanian words for" fairy"" Zână" and Sânziană, the Leonese and Portuguese word for" water nymph"" xana", and the Spanish word for" shooting target" and" morning call"(" diana") seem to come from the name of Diana. In the arts. Since the Renaissance, Diana' s myths have often been represented in the visual and dramatic arts, including the opera" L' arbore di Diana".Inthe16th century, Diana' s image figured prominently at the châteaus of Fontainebleau, Chenonceau,& amp; at Anet, in deference to Diane de Poitiers, mistress of Henri of France. At Versailles she was incorporated into the Olympian iconography with which Louis XIV, the Apollo- like" Sun King" liked to surround himself. Diana is also a character in the 1876 Léo Delibes ballet" Sylvia". The plot deals with Sylvia, one of Diana' s nymphs and sworn to chastity, and Diana' s assault on Sylvia' s affections for the shepherd Amyntas. In painting and sculpture. Diana has been one of the most popular themes in art. Painters like Titian, Peter Paul Rubens, François Boucher, Nicolas Poussin and made use of her myth as a major theme. Most depictions of Diana in art featured the stories of Diana and Actaeon, or Callisto, or depicted her resting after hunting. Some famous work of arts with a Diana theme are: Many statues of Diana huntress in Yambol, BulgariaDaniel Robert Elfman( born May 29, 1953) is an American composer, singer, and songwriter. He came to prominence as the singer- songwriter for the new wave band OingoBoingointheearly1980s.Sincethe1990s, Elfman has garnered international recognition for composing over 100 feature film scores, as well as compositions for television, stage productions, and the concert hall. Elfman has frequently worked with directors Tim Burton, Sam Raimi, and Gus Van Sant, with notable achievements including the scores of 16 Burton- directed films including" Batman,"" Edward Scissorhands, Charlie and the Chocolate Factory, Alice in Wonderland", and" Dumbo"; Raimi' s" Spider- Man"," Spider- Man 2"," Oz the Great and Powerful", and" Doctor Strange in the Multiverse of Madness"; and Van Sant' s Academy Award- nominated films" Good Will Hunting" and" Milk". He wrote music for all of the" Men in Black" and" Fifty Shades of Grey" franchise films, the songs and score for Henry Selick' s animated musical" The Nightmare Before Christmas", and the themes for the popular television series" Desperate Housewives" and" The Simpsons". Among his honors are four Oscar nominations, two Emmy Awards, a Grammy, six Saturn Awards for Best Music, the 2002 Richard Kirk Award, the 2015 Disney Legend Award, and | the Max Steiner Film Music |
Achievement Award in 2017. Early life. Elfman was born in Los Angeles, California, to a Jewish family of Polish- Jewish and Russian- Jewish descent. He is the son of Blossom Elfman( née Bernstein), a writer and teacher, and Milton Elfman, a teacher who was in the Air Force, and the brother of actor, musician, and journalist Richard Elfman. Elfman was raised in a racially mixed affluent community in Baldwin Hills, California, where he spent much of his time at the local movie theater discovering classic sci- fi, fantasy and horror films and first noticed the music of such film composers as Bernard Herrmann and Franz Waxman. In his early school days, Elfman exhibited an aptitude for science with almost no interest in music, and was even rejected from elementary school orchestra" for having no propensity for music."Thiswouldchangewhenheswitchedhighschoolsinthelate1960s and fell in with a musical crowd,whointroducedhimtoearlyjazzandtheworkofStravinskyandhis20th- century contemporaries. After finishing high school early with plans to travel the world, Elfman followed his brother Richard to France, where he performed violin with Jérôme Savary' s Le Grand Magic Circus, an avant- garde musical theater group. He then embarked on a ten- month, self- guided tour through Africa, busking and collecting a range of West African percussion instruments until a series of illnesses forced him to return home. At this time, Richard was forming a new musical theater group in Los Angeles. While Elfman was never officially a student at CalArts, an instructor in the Indonesian music department, Nyoman Wenten encouraged him to attend classes and perform music there for two years. Career. Oingo Boingo. After returningtoLosAngelesfromAfricaintheearly1970s, Elfman was asked by his brother Richard to serve as musical director of his street theatre performance art troupe The Mystic Knights of the Oingo Boingo.Elfmanwastaskedwithadaptingandarranging1920sand1930s jazz and big band music by artists such as Cab Calloway, Duke Ellington, Django Reinhardt and Josephine Baker for the ensemble, which consisted of up to 15 performers playing upwards of 30 instruments. He also composed original pieces and helped build instruments unique for the group, including an aluminum gamelan, the' Schlitz celeste' made from tuned beer cans, and a" junkyard orchestra" built from car parts and trash cans. The Mystic Knights performed on the street and in nightclubs throughout Los Angeles until Richard left in 1979 to pursue filmmaking. As a send- off to the group' s original concept, Richard created the film" Forbidden Zone" based on the Mystic Knights' stage performances. Elfman composed the songs and his first score for the film, and appeared as the character Satan, who performs a reworked version of Calloway' s" Minnie the Moocher" with ensemble members playing backup as henchmen. Before the release of" Forbidden Zone", Elfman had taken over the Mystic Knights as lead singer- songwriter in 1979, paring the group down to eight players, shortening the name to Oingo Boingo, and recording and touring as a ska- influenced new wave band. Their biggest success among eight studio albums penned by Elfman was 1985' s" Dead Man' s Party", featuring the hit song" Weird Science" from the movie of the same name. The band | also appeared performing their single" |
Dead Man' s Party" in the 1986 movie" Back to School", for which Elfman also composed the score. Elfman shifted the band to a more guitar-orientedrocksoundinthelate1980s, which continued through their last album" Boingo" in 1994. Citing permanent hearing damage from performing live and conflicts with his film- scoring career, Elfman retired Oingo Boingo in 1995 with a series of five sold- out final concerts at the Universal Amphitheatre ending on Halloween night. On October 31, 2015, Elfman and Oingo Boingo guitarist Steve Bartek performed the song" Dead Man' s Party" with an orchestra as an encore to a live- to- film concert of" The Nightmare Before Christmas" score at the Hollywood Bowl. Elfman told the audience the performance was" 20 years to the day" of Oingo Boingo' s retirement. Film scoring. As fans of Oingo Boingo, Tim Burton and Paul Reubens invited Elfman to write the score for their first feature film" Pee- wee' s Big Adventure" in 1985. Elfman was initially apprehensive because of his lack of formal training and having never scored a studio feature, but after Burton accepted his initial demo of the title music and with orchestration assistance from Oingo Boingo guitarist and arranger Steve Bartek, he completed his score to great effect, while paying homage to his love of early film music and influential film composers Nino Rota and Bernard Herrmann. Elfman described the first time he heard his music played by a full orchestra as one of the most thrilling experiences of his life. Following" Pee Wee' s Big Adventure", Elfmanscoredmainlyquirkycomediesinthelate1980s, including" Back to School" starring Rodney Dangerfield, Burton' s" Beetlejuice" and the Bill Murray vehicle" Scrooged". Notable exceptions were the all- synth score to Emilio Estevez' s crime drama" Wisdom" and the big band, blues- infused music for Martin Brest' s buddy cop action film" Midnight Run". In 1989, Elfman' s influential, Grammy- winning score for Burton' s" Batman" marked a major stylistic shift to dark, densely orchestrated music in the romantic idiom, which would carry over to his scores for Warren Beatty' s" Dick Tracy", Sam Raimi' s" Darkman" and Clive Barker' s" Nightbreed", all released in 1990. With" Batman", Elfman firmly established a career- spanning relationship with Burton, scoring all but three of the director' s major studio releases. Highlights include" Edward Scissorhands"( 1990)," Batman Returns"( 1992)," Sleepy Hollow"( 1999)," Big Fish"( 2003) and" Alice in Wonderland"( 2010). In 1993, in addition to writing the score and ten songs for the Burton- produced stop motion animated film" The Nightmare Before Christmas", Elfman also provided the singing voice for main character Jack Skellington, as well as the voices for side characters Barrel and the Clown with the Tear- Away Face. In 2005, he wrote the score and songs for Burton' s" Corpse Bride" and provided the voice of the character of Bonejangles, as well as providing the score, songs and Oompa- Loompa vocals for Burton' s" Charlie and the Chocolate Factory" that same year. In addition to frequent collaborations with Burton, Raimi and Gus Van Sant, Elfman has worked with esteemed directors such as | Brian De Palma, Peter Jackson, |
Joss Whedon, Errol Morris, Ang Lee, Richard Donner, Guillermo del Toro, David O. Russell, Taylor Hackford, Jon Amiel, Joe Johnston, and Barry Sonnenfeld. His scores for Sonnenfeld' s" Men in Black", Van Sant' s" Good Will Hunting" and" Milk", and Burton' s" Big Fish" all received Academy Award nominations. Since the mid-1990s, Elfman has expanded his craft to a range of genres, including thrillers(" Dolores Claiborne"," A Simple Plan"," The Kingdom"), dramas(" Sommersby"," A Civil Action"," Hitchcock"), indies(" Freeway"," Silver Linings Playbook"," Don' t Worry, He Won' t Get Far on Foot"), family(" Flubber"," Charlotte' s Web"," Frankenweenie"," Goosebumps"), documentary(" Standard Operating Procedure"," The Unknown Known"), and straight horror(" Red Dragon"," The Wolfman"), as well as notable entries in his well- established areas of horror comedy(" The Frighteners"," Mars Attacks!"," Dark Shadows") and comic book- inspired action films(" Hulk"," Wanted",','). Among his franchise work, Elfman composed the scores for all four" Men in Black" films( 1997– 2019) and all three" Fifty Shades of Grey" films( 2015– 2018). Elfman scored Raimi' s" Spider- Man" in 2002 and" Spider- Man 2" in 2004, themes and selections from which were used for Raimi' s" Spider- Man 3", though Elfman did not compose the score. Danny Elfman' s theme for" Spider- Man" was incorporated into the MCU film"" composed by Michael Giacchino. In 1996, he also provided the score for the first film in the, adapting themes for the original television series by Lalo Schifrin as well as composing his own. For several high- profilesequelandrebootprojectsinthe2010s, Elfman incorporated established musical themes with his own original thematic material, including the DC Extended Universe' s" Justice League"," The Grinch,"" Dumbo" and. Elfman was featured in the 2016 documentary" Score", in which he appeared among over 50 film composers to discuss the craft of movie music and influential figures in the business. Concert and stage music. Elfman' s first piece of original concert music," Serenada Schizophrana", was commissioned by the American Composers Orchestra, who premiered the piece on February 23, 2005, at Carnegie Hall. Subsequent concert works include his first" Violin Concerto" Eleven Eleven"", co- commissioned by the Czech National Symphony Orchestra, Stanford Live at Stanford University, and the Royal Scottish National Orchestra, which premiered at Smetana Hall in Prague on June 21, 2017, with Sandy Cameron on violin and John Mauceri conducting the Czech National Symphony Orchestra; the" Piano Quartet", co- commissioned by the Lied Center for Performing Arts University of Nebraska and the Berlin Philharmonic Piano Quartet, which premiered February 6, 2018, in Lincoln, Nebraska; and the" Percussion Quartet", commissioned by Third Coast Percussion and premiered at the Philip Glass Days And Nights Festival in Big Sur on October 10, 2019. In 2008, Elfman accepted his first commission for the stage, composing the music for Twyla Tharp' s" Rabbit and Rogue" ballet, co- commissioned by American Ballet Theatre and Orange County Performing Arts Center and premiering on June 3, 2008, at the Metropolitan Opera House, Lincoln Center. Other works for stage include the music for Cirque Du Soleil' s" Iris" in 2011, and incidental music for the Broadway | production of Taylor Mac' s"" |
in 2019. In October 2013, Elfman returned to the stage for the first time since his band Oingo Boingo disbanded to sing his vocal parts to a handful of" The Nightmare Before Christmas" songs as part of a concert titled" Danny Elfman' s Music from the Films of Tim Burton", featuring suites of music from 15 Tim Burton films newly arranged by Elfman. The concert has since toured internationally and has played in Japan, Australia, Mexico and throughout Europe and the United States. Since 2015, Elfman has appeared near annually in a Hollywood Bowl Halloween concert featuring full orchestra performing the" Nightmare Before Christmas" score live to the film projection. In 2019, it was announced Elfman had been commissioned to write a piece for the National Youth Orchestra of Great Britain originally set to premiere in 2020, and a percussion concerto for Colin Currie the London Philharmonic Orchestra and Soka University of America originally for spring 2021, later rescheduled for spring 2022. Other works in the planning phase are a cello concerto for Gautier Capucon to premiere in Vienna, Paris and San Francisco in 2022, and a project that involves chamber orchestra and Elfman' s own voice. It was announced that Elfman would be taking part in Coachella 2020 with a set titled" Past, Present and Future! From Boingo to Batman and Beyond!" Elfman clarified on his Instagram page that this would not be an Oingo Boingo reunion, writing" I’ m creating a live mix of my last 40 years— both film music and songs... that includes my Boingo years, my composer years and a few things I’ ve been working on for the last year or so, which will be world premieres." Television and other projects. In addition to his music for film, Elfman has also penned themes for" The Simpsons"," Tales from the Crypt"," The Flash" and" Desperate Housewives", which won Elfman his first Emmy. He also adapted his original themes for the animated versions of"" and" Beetlejuice". Occasional forays into serial television include episodes of" Alfred Hitchcock Presents"," Amazing Stories" and Pee- wee' s Playhouse, as well as the miniseries" When We Rise", co- composed with Chris Bacon. He has composed music for animated shorts, including Sally Cruikshank' s" Face Like A Frog" and Tim Burton' s" Stainboy" internet series. Elfman provided background music for Luigi Serafini' s solo exhibition" il Teatro della Pittura" at the Fondazione Mudima di Milano in Milan, Italy in 1998 and for the" Tim Burton" exhibition at MoMA in 2009.Inthe1990s, Elfman composed music for advertising campaigns for Nike, Nissan and Lincoln- Mercury, and in 2002 wrote the music for Honda' s" Power of Dreams" advertising campaign, which was the first cinema commercial to be shot in the IMAX format. In 2013 he composed the music and provided the English- language vocals for the Hong Kong Disneyland attraction Mystic Manor. On October 31, 2019, the MasterClass online educational series released" Making Music out of Chaos," presenting 21 compositional and career lessons from Elfman' s four decades of experience primarily in the film industry. Elfman scored | the 10- minute video" Joe |
Biden," which introduced Joe Biden' s acceptance of the presidential candidacy nomination at the 2020 Democratic National Convention. In October 2020, Elfman released a surprise single," Happy," on Anti- Records and Epitaph Records. From January 2021, he released the five following singles" Sorry"," Love In The Time of COVID"," Kick Me"," True", and a reworking of a song from his time in Oingo Boingo,“ Insects”, from the album" Nothing to Fear",onthe11th date of each month. An album," Big Mess", was released on June 11. On August 11, 2021, Elfman released a remix of“ True” with lead vocals shared between Elfman and Nine Inch Nails frontman Trent Reznor. Influences and style. Elfman has said his major influences are composers from Hollywood' s Golden Age, such as Bernard Herrmann, Dimitri Tiomkin, Max Steiner, David Tamkin, Erich Wolfgang Korngold, and Carl Stalling;20th century classical composers Sergei Prokofiev, Igor Stravinsky, Béla Bartók, Dmitri Shostakovich, and Carl Orff; and jazz, experimental and minimalist composers Kurt Weill, Duke Ellington, Harry Partch, Philip Glass, Lou Harrison, Terry Riley, and Steve Reich. Influences on specific scores include Erik Satie(" Forbidden Zone)", Nino Rota(" Pee- wee' s Big Adventure"), George Gershwin(" Dick Tracy"), Pyotr Ilyich Tchaikovsky(" Edward Scissorhands"), and Jimi Hendrix(" Dead Presidents"). Though not considered direct influences" per se", Elfman has discussed his respect and admiration for film composers Jerry Goldsmith, Ennio Morricone, Thomas Newman, Alexandre Desplat and John Williams, as well as classical composer John Adams. Though many believe Richard Wagner informed his influential score to" Batman", Elfman has said it was more likely from Wagner' s influence on classic film composers such as Herrmann, Steiner, Waxman and Korngold, as he was unfamiliar with Wagner' s work at the time. Elfman counts Herrmann as his biggest influence, and has said hearing Herrmann' s score to" The Day the Earth Stood Still" when he was a child was the first time he recognized film music as a cinematic art form and realized the powerful contribution a composer makes to the movies. Pastiche of Herrmann' s music can be heard in Elfman' s" Pee- Wee' s Big Adventure," especially the cues" Stolen Bike" and" Clown Dream", which directly reference Herrmann' s music from" Psycho" and"The7th Voyage of Sinbad" respectively. His score to" Batman" makes more subtle nods to Herrmann' s" Journey to the Center of the Earth" and" Vertigo", and more integral homage can be heard in later scores for" Mars Attacks!" and" Hitchcock," as well as the" Blue Strings" movement of his first concert work" Serenada Schizophrana". While Elfman is primarily known for writing large- scale orchestral works in the romantic,20th century and Hollywood Golden Age film score traditions, his compositions have used a wide range of idioms, including rock and blues(" Midnight Run, Hot to Trot"), big band and jazz(" Dick Tracy"," Chicago"), operetta(" The Nightmare Before Christmas"," Corpse Bride"), funk and hip hop(" Dead Presidents"," Notorious"), folk and indie rock(" Taking Woodstock"," Silver Linings Playbook"), Americana(" Article 99"," Sommersby"," Big Fish)," minimalism(" Good Will Hunting"," Standard Operating Procedure"," The Unknown Known"), and atonal or experimental(" Freeway"," A Simple | Plan, The Girl on the |
Train"). Given his appreciation and study of world music and his vast collection of instruments from non- Western cultures, Elfman will often use traditional instruments in his scores when there is an international setting, such as African percussion for" Instinct," the oud for" The Kingdom" set in Saudi Arabia, and pan flute for" Proof of Life" set in South America. When working on films with established musical identifiers, Elfman will often incorporate original themes in addition to his own thematic material. Examples include Lalo Schifrin' s main theme and" The Plot" from the original for""; John Williams' theme for" Superman", the Hans Zimmer/ Junkie XL theme for" Wonder Woman" and his own original" Batman" theme for" Justice League;" the" Welcome Christmas" song from the 1966" How the Grinch Stole Christmas!" for" The Grinch"; and" Casey Junior,"" Pink Elephants on Parade," and" When I See an Elephant Fly" from Disney' s original 1941 animated film for" Dumbo". Even when not directly quoting themes from related films, Elfman will often pay homage through established musical gesture or tonality, for example Howard Shore' s" The Silence of the Lambs" for" Red Dragon", Brad Fiedel' s music for the" Terminator" franchise for" Terminator Salvation", Robert Cobert' s original television series music for" Dark Shadows," and Alan Silvestri' s work on" The Avengers" for the sequel"". Notable exceptions are Tim Burton' s" Batman"," Planet of the Apes" and" Charlie and the Chocolate Factory," which do not make musical reference to pre existing material. The songs for" The Nightmare Before Christmas" and" Corpse Bride" were influenced by Kurt Weill, Gilbert and Sullivan and early Rodgers and Hammerstein. At the request of Tim Burton," Charlie and the Chocolate Factory" songs drew inspiration from Bollywood, the Mamas and the Papas, ABBA, Queen, and Earth, Wind& amp; Fire individually. Elfman' s work in pop music and specifically as songwriter for Oingo Boingo was influenced by the Specials, Madness, the Selecter, Devo, Fun Boy Three, and XTC. Process. Film music. For his film scores, Elfman draws musical inspiration almost exclusively from viewing a cut of the film, and occasionally from visits to the set while the film is in production( he wrote and orchestrated his theme for" Batman" on an airplane to Los Angeles after visiting the set in London). While he prefers not to work from script, story or concept, notable exceptions are" The Nightmare Before Christmas," for which ten songs needed to be written in advance of filmmaking, and" Dumbo," for which he composed the main theme before filming began. Once a rough cut of the film is ready, Elfman and the director have a spotting session to decide where to place music in the film, the emotional undercurrents of each scene, and overall tone. Elfman then spends a few weeks of free composition and experimentation to begin working out thematic material and to develop sounds and the harmonic pallette. When he has received approval on initial material from the filmmakers, Elfman begins to compose anywhere from 60 to 120 minutes of music cue- by- cue. He says two of | the most important things to |
capture at this point are the tone of each scene and editorial rhythm. Next to thematic development, action set pieces tend to take Elfman the most time given the complexity of timing music to action. One element where Elfman' s compositional process deviates from most film composers is that he will often compose three or more often radically different versions of a single cue to give the director more options for musicalizing a scene. Early in his career, he wrote out his scores using pencil, but has composed largely digitally since the mid-1990s. Before recording the score, he demos each cue by mocking orchestral and choral parts on synthesizer to get approval from the director. Once approved, he provides a detailed, multi- line sketch of his composition to his lead orchestrator Steve Bartek, who ensures the sketches are appropriately broken down for sections of the orchestra( i. e. string, brass woodwind, some percussion), choir( SATB) and individual players. Elfman also typically samples or records his own percussion and guitar playing to overlay with live orchestra. More than half of some scores feature Elfman' s performance, including" Dead presidents",""," Planet of the Apes"," The Kingdom"," The Girl on the Train" and" The Circle." To produce the score, Elfman rents a recording studio and hires a conductor and orchestra/ choir. He oversees the recording from the control booth so that he can troubleshoot with the film' s director and recording engineers. The final recording is given to the film' s sound department to mix with dialogue and sound effects for the film' s complete soundtrack. Elfman will usually do a separate mix of select cues for an album presentation of the score, and has produced nearly 100 to date. On the occasion that there are compressed deadlines or in the event he is not available to rescore or adapt his music if there are major edits to the film after the score' s completion, Elfman will hire additional composers to work on small cues or sections of cues, adapting his existing material or themes. Examples include Jonathan Sheffer on" Darkman", David Buckley on the" Fifty Shades of Grey" films, and Pinar Toprak on" Justice League."Sincethe1990s, Elfman has occasionally co- composed music or shared music writing credit( e. g." When We Rise"," Spy Kids",","), or written themes that are then used or adapted by other composers, including Jonathan Sheffer(" Pure Luck"), Steve Bartek(" Novacaine"), John Debney(" Heartbreakers)," Deborah Lurie(" 9"), and the Newton Brothers(" Before I Wake"). Concert music. In the liner notes for the 2006 CD recording of his first concert work" Serenada Schizophrana", Elfman wrote:" I began composing several dozen short improvisational compositions, maybe a minute each. Slowly, some of them began to develop themselves until finally I had six separate movements that, in some abstract, absurd way, felt connected." To create the cadenzas for his violin concerto" Eleven Eleven", Elfman collaborated with soloist Sandy Cameron, for whom the piece was written. Vocals. Elfman often incorporates choral or vocal arrangements into his film scores, notably the use of women' s and children' s | choirs(" Scrooged"," Nightbreed, Edward Scissorhands, |
Batman Returns"," Sleepy Hollow, Alice in Wonderland"," The Grinch"), and solo voice or vocal effects(" Beetlejuice"," Mars Attacks!"," Men in Black II"," Flubber"," Nacho Libre"," Iris"," Dark Shadows"," The Girl on the Train"). Evoking the" O Fortuna" from Carl Orff' s" Carmina Burana", he set made- up, Latin- sounding text for SATB choir in standout cue" Descent into Mystery" from" Batman." Elfman also adds his own vocals into compositions in much the same way he mixes his percussion and guitar performances into orchestral arrangements. Prominent use can be heard in the scores for" To Die For"( sung with director Gus Van Sant, credited to" Little Gus and the Suzettes")," Silver Linings Playbook", and his music for the Hong Kong Disneyland ride Mystic Manor. He provided the singing voice for characters in" The Nightmare Before Christmas" and" Corpse Bride" in addition to composing the scores and songs"," and can be heard singing the" Day- O" call in the style of Harry Belafonte' s" Banana Boat Song" in the first bars of the" Beetlejuice" main title. For Tim Burton' s" Charlie and the Chocolate Factory," Elfman set Roald Dahl' s text for the Oompa- Loompa characters as four stylistically distinct songs: the Bollywood- influenced" Augustus Gloop," the funk- infused" Violet Beauregarde," the psychedelic pop stylings of" Veruca Salt," and the baroque rock of" Mike Teevee." For all songs in the film, Elfman sang, manipulated and mixed several layers of his vocals to create the singing voices and harmonies of the Oompa Loompas, and incorporated his vocals into non- song score tracks that featured the characters, including" Loompa Land,"" Chocolate River,"" The Boat Arrives," and" The River Cruise." Lyrics. Rare among film composers, Elfman typically writes the lyrics to songs he has composed for movies. He employs song structures from Tin Pan Alley and early musical theatre composers( 32- bar form),andpopandrockofthe1950sand1960s( verse- chorus). As his songs serve to advance the plot and develop characters, lyrics reflect storylines and imagery specific to the film and express the inner life of characters. A major achievement was writing the lyrics and music for ten songs featured in the stop- motion musical" The Nightmare Before Christmas". Drawing from Tim Burton' s parody poem of" A Visit from St. Nicholas" and concept drawings, Elfman wrote each song in consultation with Burton before the film even had a script. These include the full- cast songs" This Is Halloween,"" Town Meeting Song," and" Making Christmas"; four songs for the main character Jack Skellington" Jack' s Lament,"" What' s This,"" Jack' s Obsession," and" Poor Jack" all sung by Elfman; and the other character songs" Kidnap the Sandy Claws,"" Oogie Boogie' s Song," and" Sally' s Song." An eleventh song," Finale/ Reprise," reworks lyrics from the songs" This Is Halloween,"" What' s This" and" Sally' s Song" for the film' s ending. Though uncredited, Burton contributed some lyrics to" Nightmare", including the line" Perhaps it' s the head that I found in the lake" in" Town Meeting Song." Elfman composed five songs for Burton' s" Corpse Bride":" According to Plan" with lyrics co- | written by screenwriter John August;" |
Remains of the Day," which he sung as the character Bonejangles, and" Tears To Shed," both with additional lyrics by August, and" The Wedding Song" credited solely to Elfman. The song" Erased" was not used in the final film. He wrote the lyrics to" Lullaby" from" Charlotte' s Web", the rock track" The Little Things" from" Wanted" which he also sang in English and Russian, and" Alice' s Theme" from" Alice in Wonderland". Elfman co- wrote the music and lyrics to Batman Returns' s" Face To Face" with Siouxsie and the Banshees, and co- wrote the lyrics to" Twice the Love" from" Big Fish" and the" Wonka' s Welcome Song" for" Charlie and the Chocolate Factory" with John August. Elfman wrote the lyrics to all of Oingo Boingo' s original songs 1979– 1994 and has made residuals on the titular two- word opening phrase sung in his" The Simpsons" theme since the series first aired in 1989. Personal life. As a teenager, Elfman dated his classmate Kim Gordon, who would later become one of the members of the rock band Sonic Youth. He has two daughters, Lola and Mali, from his marriage to Geri Eisenmenger. Mali is a film producer and actress. Elfman and Mali collaborated on her 2011 film" Do Not Disturb". On November 29, 2003, Elfman married actress Bridget Fonda. They have a son, Oliver. In 1998, Elfman scored" A Simple Plan", starring Fonda. He is the uncle of actor Bodhi Elfman, who is married to actress Jenna Elfman. Elfman has been an atheist since the age of 11 or 12. According to him, he is a cynicologist.Describinghispoliticsduringthe1980s, Elfman said," I' m not a doomist. My attitude is always to be critical of what' s around you, but not ever to forget how lucky we are. I' ve traveled around the world. I left thinking I was a revolutionary. I came back real right- wing patriotic. Since then, I' ve kind of mellowed in between." Several of his songs written for Oingo Boingo during this period satirized social politics, although Elfman stated his message was to" question, resist, challenge" and that his songs were not aligned to any one political agenda. In 2008, Elfman expressed support for Barack Obama. For the 2020 Democratic National Convention, he scored the biographical video played ahead of Joe Biden' s acceptance of the presidential nomination in the 2020 United States elections. In a series of posts on his Instagram page discussing the video, Elfman criticized Donald Trump, Richard Nixon, and the electoral college, and linked to several voter resources. During his 18 years with Oingo Boingo, Elfman developed significant hearing damage as a result of the continuous exposure to the high noise levels involved in performing in a rock band. Afraid of worsening his condition, he decided to leave the band, saying that he would never return to that kind of performance. His impairment was so bad that he could not" even sit in a loud restaurant or bar anymore." However, he found performing in front of orchestras more tolerable, and returned several times | to reprise his live performance |
of Jack Skellington. In popular culture. Since" The Simpsons"' second annual" Treehouse of Horror" episode aired in 1991, launching" scary names" tradition in the opening and closing titles, Elfman has been alternately credited for the theme music as" Red Wolf Elfman,"" Danny Skellingelfman,"" Li' l Leakin Brain Elfman,"" Boris Elfmonivich,"" Danny Elfblood,"" Danny' Hell' fman,"" The Bloody Elf,"" Danny Elfbones,"" Elfmunster" and" Daniel Beilzebelsman." Elfman' s composition" Clown Dream" from" Pee- wee' s Big Adventure" is used in the video game" Grand Theft Auto V" and has often been used as the opening music for Primus concerts. In the 2007 sixth season" Star Wars" parody" Blue Harvest"," Family Guy" lampooned Elfman' s orchestral style. A scene shows Elfman replacing an incinerated John Williams to conduct a full orchestra playing the score, only to be decapitated by a lightsaber after conducting a few bars of oom- pah music.Episodefiveofthe14th season of" South Park" in 2010 criticized Tim Burton for using the" same" music in all his films, referring to Elfman' s scores. In October 2016, Elfman produced a video clip for Funny or Die with original" horror" music composed to footage of Donald Trump pacing around Hillary Clinton at the second United States presidential election debates, 2016. In 2019, selections from Elfman' s" Midnight Run" score were used in the third season of Netflix' s" Stranger Things," including" Stairway Chase" in episodes 5 and 6, and" Wild Ride" and" Package Deal" in episode 6. Christina Aguilera revealed that Elfman' s music inspired her Las Vegas concert residency The Xperience. Awards and nominations. American Film Institute. Elfman' s scores for" Batman" and" Edward Scissorhands" were nominated for AFI' s 100 Years of Film Scores. Discography. Including commercial recordings of his film scores and the Oingo Boingo discography, Elfman has produced over 100 albums as of 2019. In physics and mathematics, the dimension of a mathematical space( or object) is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one(1D) because only one coordinate is needed to specify a point on itfor example, the point at 5 on a number line. A surface such as a plane or the surface of a cylinder or sphere has a dimension of two(2D) because two coordinates are needed to specify a point on itfor example, both a latitude and longitude are required to locate a point on the surface of a sphere. The inside of a cube, a cylinder or a sphere is three- dimensional(3D) because three coordinates are needed to locate a point within these spaces. In classical mechanics, space and time are different categories and refer to absolute space and time. That conception of the world is a four- dimensional space but not the one that was found necessary to describe electromagnetism. The four dimensions(4D) of spacetime consist of events that are not absolutely defined spatially and temporally, but rather are known relative to the motion of an observer. Minkowski space first approximates the universe without gravity; the pseudo- Riemannian manifolds of general relativity | describe spacetime with matter and |
gravity. 10 dimensions are used to describe superstring theory(6D hyperspace+4D), 11 dimensions can describe supergravity and M- theory(7D hyperspace+4D), and the state- space of quantum mechanics is an infinite- dimensional function space. The concept of dimension is not restricted to physical objects. s frequently occur in mathematics and the sciences. They may be parameter spaces or configuration spaces such as in Lagrangian or Hamiltonian mechanics; these are abstract spaces, independent of the physical space in which we live. In mathematics. In mathematics, the dimension of an object is, roughly speaking, the number of degrees of freedom of a point that moves on this object. In other words, the dimension is the number of independent parameters or coordinates that are needed for defining the position of a point that is constrained to be on the object. For example, the dimension of a point is zero; the dimension of a line is one, as a point can move on a line in only one direction( or its opposite); the dimension of a plane is two, etc. The dimension is an intrinsic property of an object, in the sense that it is independent of the dimension of the space in which the object is or can be embedded. For example, a curve, such as a circle, is of dimension one, because the position of a point on a curve is determined by its signed distance along the curve to a fixed point on the curve. This is independent from the fact that a curve cannot be embedded in a Euclidean space of dimension lower than two, unless it is a line. The dimension of Euclidean- space is. When trying to generalize to other types of spaces, one is faced with the question" what makes- dimensional?" One answer is that to cover a fixed ball in by small balls of radius, one needs on the order of such small balls. This observation leads to the definition of the Minkowski dimension and its more sophisticated variant, the Hausdorff dimension, but there are also other answers to that question. For example, the boundary of a ball in looks locally like and this leads to the notion of the inductive dimension. While these notions agree on, they turn out to be different when one looks at more general spaces. A tesseract is an example of a four- dimensional object. Whereas outside mathematics the use of the term" dimension" is as in:" A tesseract" has four dimensions"", mathematicians usually express this as:" The tesseract" has dimension 4"", or:" The dimension of the tesseract" is" 4" or:4D. Although the notion of higher dimensions goes back to René Descartes, substantial development of a higher- dimensional geometryonlybeganinthe19th century, via the work of Arthur Cayley, William Rowan Hamilton, Ludwig Schläfli and Bernhard Riemann. Riemann' s 1854 Habilitationsschrift, Schläfli' s 1852" Theorie der vielfachen Kontinuität", and Hamilton' s discovery of the quaternions and John T. Graves' discovery of the octonions in 1843 marked the beginning of higher- dimensional geometry. The rest of this section examines some of the more important mathematical definitions of dimension. Vector | spaces. The dimension of a |
vector space is the number of vectors in any basis for the space, i. e. the number of coordinates necessary to specify any vector. This notion of dimension( the cardinality of a basis) is often referred to as the" Hamel dimension" or" algebraic dimension" to distinguish it from other notions of dimension. For the non- free case, this generalizes to the notion of the length of a module. Manifolds. The uniquely defined dimension of every connected topological manifold can be calculated. A connected topological manifold is locally homeomorphic to Euclidean- space, in which the number is the manifold' s dimension. For connected differentiable manifolds, the dimension is also the dimension of the tangent vector space at any point. In geometric topology, the theory of manifolds is characterized by the way dimensions 1 and 2 are relatively elementary, the high- dimensional cases are simplified by having extra space in which to" work"; and the cases and are in some senses the most difficult. This state of affairs was highly marked in the various cases of the Poincaré conjecture, in which four different proof methods are applied. Complex dimension. The dimension of a manifold depends on the base field with respect to which Euclidean space is defined. While analysis usually assumes a manifold to be over the real numbers, it is sometimes useful in the study of complex manifolds and algebraic varieties to work over the complex numbers instead. A complex number(" x"+" iy") has a real part" x" and an imaginary part" y", in which x and y are both real numbers; hence, the complex dimension is half the real dimension. Conversely, in algebraically unconstrained contexts, a single complex coordinate system may be applied to an object having two real dimensions. For example, an ordinary two- dimensional spherical surface, when given a complex metric, becomes a Riemann sphere of one complex dimension. Varieties. The dimension of an algebraic variety may be defined in various equivalent ways. The most intuitive way is probably the dimension of the tangent space at any Regular point of an algebraic variety. Another intuitive way is to define the dimension as the number of hyperplanes that are needed in order to have an intersection with the variety that is reduced to a finite number of points( dimension zero). This definition is based on the fact that the intersection of a variety with a hyperplane reduces the dimension by one unless if the hyperplane contains the variety. An algebraic set being a finite union of algebraic varieties, its dimension is the maximum of the dimensions of its components. It is equal to the maximal lengthofthechainsformula_1 of sub- varieties of the given algebraic set( the length of such a chain is the number of"formula_2"). Each variety can be considered as an algebraic stack, and its dimension as variety agrees with its dimension as stack. There are however many stacks which do not correspond to varieties, and some of these have negative dimension. Specifically, if" V" is a variety of dimension" m" and" G" is an algebraic group of dimension" n" acting | on" V", then the quotient |
stack[" V"/" G"] has dimension" m"−" n". Krull dimension. The Krull dimension of a commutative ring is the maximal length of chains of prime ideals in it, a chain of length" n"beingasequenceformula_3 of prime ideals related by inclusion. It is strongly related to the dimension of an algebraic variety, because of the natural correspondence between sub- varieties and prime ideals of the ring of the polynomials on the variety. For an algebra over a field, the dimension as vector space is finite if and only if its Krull dimension is 0. Topological spaces. For any normal topological space, the Lebesgue covering dimension of is defined to be the smallest integer" n" for which the following holds: any open cover has an open refinement( a second open cover in which each element is a subset of an element in the first cover) such that no point is included in more than elements. In this case dim. For a manifold, this coincides with the dimension mentioned above. If no such integer exists, then the dimension of is said to be infinite, and one writes dim. Moreover, has dimension− 1, i. e. dim if and only if is empty. This definition of covering dimension can be extended from the class of normal spaces to all Tychonoff spaces merely by replacing the term" open" in the definition by the term" functionally open". An inductive dimension may be defined inductively as follows. Consider a discrete set of points( such as a finite collection of points) to be 0- dimensional. By dragging a 0- dimensional object in some direction, one obtains a 1- dimensional object. By dragging a 1- dimensional object in a" new direction", one obtains a 2- dimensional object. In general one obtains an()- dimensional object by dragging an- dimensional object in a" new" direction. The inductive dimension of a topological space may refer to the" small inductive dimension" or the" large inductive dimension", and is based on the analogy that, in the case of metric spaces, balls have- dimensional boundaries, permitting an inductive definition based on the dimension of the boundaries of open sets. Moreover, the boundary of a discrete set of points is the empty set, and therefore the empty set can be taken to have dimension- 1. Similarly, for the class of CW complexes, the dimension of an object is the largest for which the- skeleton is nontrivial. Intuitively, this can be described as follows: if the original space can be continuously deformed into a collection of higher- dimensional triangles joined at their faces with a complicated surface, then the dimension of the object is the dimension of those triangles. Hausdorff dimension. The Hausdorff dimension is useful for studying structurally complicated sets, especially fractals. The Hausdorff dimension is defined for all metric spaces and, unlike the dimensions considered above, can also have non- integer real values. The box dimension or Minkowski dimension is a variant of the same idea. In general, there exist more definitions of fractal dimensions that work for highly irregular sets and attain non- integer positive real values. Fractals have | been found useful to describe |
many natural objects and phenomena. Hilbert spaces. Every Hilbert space admits an orthonormal basis, and any two such bases for a particular space have the same cardinality. This cardinality is called the dimension of the Hilbert space. This dimension is finite if and only if the space' s Hamel dimension is finite, and in this case the two dimensions coincide. In physics. Spatial dimensions. Classical physics theories describe three physical dimensions: from a particular point in space, the basic directions in which we can move are up/ down, left/ right, and forward/ backward. Movement in any other direction can be expressed in terms of just these three. Moving down is the same as moving up a negative distance. Moving diagonally upward and forward is just as the name of the direction implies;" i. e.", moving in a linear combination of up and forward. In its simplest form: a line describes one dimension, a plane describes two dimensions, and a cube describes three dimensions.( See Space and Cartesian coordinate system.) Time. A temporal dimension, or time dimension, is a dimension of time. Time is often referred to as the" fourth dimension" for this reason, but that is not to imply that it is a spatial dimension. A temporal dimension is one way to measure physical change. It is perceived differently from the three spatial dimensions in that there is only one of it, and that we cannot move freely in time but subjectively move in one direction. The equations used in physics to model reality do not treat time in the same way that humans commonly perceive it. The equations of classical mechanics are symmetric with respect to time, and equations of quantum mechanics are typically symmetric if both time and other quantities( such as charge and parity) are reversed. In these models, the perception of time flowing in one direction is an artifact of the laws of thermodynamics( we perceive time as flowing in the direction of increasing entropy). The best- known treatment of time as a dimension is Poincaré and Einstein' s special relativity( and extended to general relativity), which treats perceived space and time as components of a four- dimensional manifold, known as spacetime, and in the special, flat case as Minkowski space. Time is different from other spatial dimensions as time operates in all spatial dimensions. Time operates in the first, second and third as well as theoretical spatial dimensions such as a fourth spatial dimension. Time is not however present in a single point of absolute infinite singularity as defined as a geometric point, as an infinitely small point can have no change and therefore no time. Just as when an object moves through positions in space, it also moves through positions in time. In this sense the force moving any object to change is" time". Additional dimensions. In physics, three dimensions of space and one of time is the accepted norm. However, there are theories that attempt to unify the four fundamental forces by introducing extra dimensions/ hyperspace. Most notably, superstring theory requires 10 spacetime dimensions, and | originates from a more fundamental |
11- dimensional theory tentatively called M- theory which subsumes five previously distinct superstring theories.Supergravitytheoryalsopromotes11D spacetime=7D hyperspace+ 4 common dimensions. To date, no direct experimental or observational evidence is available to support the existence of these extra dimensions. If hyperspace exists, it must be hidden from us by some physical mechanism. One well- studied possibility is that the extra dimensions may be" curled up" at such tiny scales as to be effectively invisible to current experiments. Limits on the size and other properties of extra dimensions are set by particle experiments such as those at the Large Hadron Collider. In 1921, Kaluza–Kleintheorypresented5D including an extra dimension of space. At the level of quantum field theory, Kaluza– Klein theory unifies gravity with gauge interactions, based on the realization that gravity propagating in small, compact extra dimensions is equivalent to gauge interactions at long distances. In particular when the geometry of the extra dimensions is trivial, it reproduces electromagnetism. However at sufficiently high energies or short distances, this setup still suffers from the same pathologies that famously obstruct direct attempts to describe quantum gravity. Therefore, these models still require a UV completion, of the kind that string theory is intended to provide. In particular, superstring theory requires six compact dimensions(6D hyperspace) forming a Calabi– Yau manifold. Thus Kaluza- Klein theory may be considered either as an incomplete description on its own, or as a subset of string theory model building. In addition to small and curled up extra dimensions, there may be extra dimensions that instead aren' t apparent because the matter associated with our visible universe is localized on a subspace. Thus the extra dimensions need not be small and compact but may be large extra dimensions. D- branes are dynamical extended objects of various dimensionalities predicted by string theory that could play this role. They have the property that open string excitations, which are associated with gauge interactions, are confined to the brane by their endpoints, whereas the closed strings that mediate the gravitational interaction are free to propagate into the whole spacetime, or" the bulk". This could be related to why gravity is exponentially weaker than the other forces, as it effectively dilutes itself as it propagates into a higher- dimensional volume. Some aspects of brane physics have been applied to cosmology. For example, brane gas cosmology attempts to explain why there are three dimensions of space using topological and thermodynamic considerations. According to this idea it would be since three is the largest number of spatial dimensions in which strings can generically intersect. If initially there are many windings of strings around compact dimensions, space could only expand to macroscopic sizes once these windings are eliminated, which requires oppositely wound strings to find each other and annihilate. But strings can only find each other to annihilate at a meaningful rate in three dimensions, so it follows that only three dimensions of space are allowed to grow large given this kind of initial configuration. Extra dimensions are said to be universal if all fields are equally free to propagate within them. In | computer graphics and spatial data. |
Several types of digital systems are based on the storage, analysis, and visualization of geometric shapes, including illustration software, Computer- aided design, and Geographic information systems. Different vector systems use a wide variety of data structures to represent shapes, but almost all are fundamentally based on a set of geometric primitives corresponding to the spatial dimensions: Frequently in these systems, especially GIS and Cartography, a representation of a real- world phenomena may have a different( usually lower) dimension than the phenomenon being represented. For example, a city( a two- dimensional region) may be represented as a point, or a road( a three- dimensional volume of material) may be represented as a line. This" dimensional generalization" correlates with tendencies in spatial cognition. For example, asking the distance between two cities presumes a conceptual model of the cities as points, while giving directions involving travel" up,"" down," or" along" a road imply a one- dimensional conceptual model. This is frequently done for purposes of data efficiency, visual simplicity, or cognitive efficiency, and is acceptable if the distinction between the representation and the represented is understood, but can cause confusion if information users assume that the digital shape is a perfect representation of reality( i. e., believing that roads really are lines). Networks and dimension. Some complex networks are characterized by fractal dimensions. The concept of dimension can be generalized to include networks embedded in space. The dimension characterize their spatial constraints. In literature. Science fiction texts often mention the concept of" dimension" when referring to parallel or alternate universes or other imagined planes of existence. This usage is derived from the idea that to travel to parallel/ alternate universes/ planes of existence one must travel in a direction/ dimension besides the standard ones. In effect, the other universes/ planes are just a small distance away from our own, but the distance is in a fourth( or higher) spatial( or non- spatial) dimension, not the standard ones. One of the most heralded science fiction stories regarding true geometric dimensionality, and often recommended as a starting point for those just starting to investigate such matters, is the 1884 novella" Flatland" by Edwin A. Abbott. Isaac Asimov, in his foreword to the Signet Classics 1984 edition, described" Flatland" as" The best introduction one can find into the manner of perceiving dimensions." The idea of other dimensions was incorporated into many early science fiction stories, appearing prominently, for example, in Miles J. Breuer' s" The Appendix and the Spectacles"( 1928) and Murray Leinster' s" The Fifth- Dimension Catapult"( 1931); and appeared irregularly in science fictionbythe1940s. Classic stories involving other dimensions include Robert A. Heinlein' s"— And He Built a Crooked House"( 1941), in which a California architect designs a house based on a three- dimensional projection of a tesseract; Alan E. Nourse' s" Tiger by the Tail" and" The Universe Between"( both 1951); and" The Ifth of Oofth"( 1957) by Walter Tevis. Another reference is Madeleine L' Engle' s novel" A Wrinkle In Time"( 1962), which uses the fifth dimension as a way for" tesseracting the universe" or" | folding" space in order to |
move across it quickly. The fourth and fifth dimensions are also a key component of the book" The Boy Who Reversed Himself" by William Sleator. In philosophy. Immanuel Kant, in 1783, wrote:" That everywhere space( which is not itself the boundary of another space) has three dimensions and that space in general cannot have more dimensions is based on the proposition that not more than three lines can intersect at right angles in one point. This proposition cannot at all be shown from concepts, but rests immediately on intuition and indeed on pure intuition" a priori" because it is apodictically( demonstrably) certain."" Space has Four Dimensions" is a short story published in 1846 by German philosopher and experimental psychologist Gustav Fechner under the pseudonym" Dr. Mises". The protagonist in the tale is a shadow who is aware of and able to communicate with other shadows, but who is trapped on a two- dimensional surface. According to Fechner, this" shadow- man" would conceive of the third dimension as being one of time. The story bears a strong similarity to the" Allegory of the Cave" presented in Plato' s" The Republic"( 380 BC). Simon Newcomb wrote an article for the" Bulletin of the American Mathematical Society" in 1898 entitled" The Philosophy of Hyperspace". Linda Dalrymple Henderson coined the term" hyperspace philosophy", used to describe writing that uses higher dimensions to explore metaphysical themes, in her 1983 thesis about the fourth dimension in early- twentieth- century art. Examples of" hyperspace philosophers" include Charles Howard Hinton, the first writer, in 1888, to use the word" tesseract"; and the Russian esotericist P. D. Ouspensky. Dissolve may refer to: The duodecimal system( also known as base 12, dozenal, or, rarely, uncial) is a positional notation numeral system using twelve as its base. The number twelve( that is, the number written as" 12" in the base ten numerical system) is instead written as" 10" in duodecimal( meaning" 1 dozen and 0 units", instead of" 1 ten and 0 units"), whereas the digit string" 12" means" 1 dozen and 2 units"( i. e. the same number that in decimal is written as" 14"). Similarly, in duodecimal" 100" means" 1 gross"," 1000" means" 1 great gross", and" 0. 1" means" 1 twelfth"( instead of their decimal meanings" 1 hundred"," 1 thousand", and" 1 tenth"). Various symbols have been used to stand for ten and eleven in duodecimal notation; this page uses and, as in hexadecimal, which make a duodecimal count from zero to twelve read 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,,, 10. The number twelve, a superior highly composite number, is the smallest number with four non- trivial factors( 2, 3, 4, 6), and the smallest to include as factors all four numbers( 1 to 4) within the subitizing range, and the smallest abundant number. All multiples of reciprocals of 3- smooth numbers( where are integers) have a terminating representation in duodecimal. In particular,( 0. 3),( 0. 4),( 0. 6),( 0. 8), and( 0. 9) all have a short terminating representation in duodecimal. There is also higher | regularity observable in the duodecimal |
multiplication table. As a result, duodecimal has been described as the optimal number system. This is considered superior to base- 10( which has only 2 and 5 as factors), and also to other proposed bases such as 16 or 20. Base- 60( and the less popular base- 30) do even better in this respect( the reciprocals of all 5- smooth numbers terminate) but at the cost of unwieldy multiplication tables and a much larger number of symbols to memorize. Origin. Languages using duodecimal number systems are uncommon. Languages in the Nigerian Middle Belt such as Janji, Gbiri- Niragu( Gure- Kahugu), Piti, and the Nimbia dialect of Gwandara; and the Chepang language of Nepal are known to use duodecimal numerals. Germanic languages have special words for 11 and 12, such as" eleven" and" twelve" in English. They come from Proto- Germanic*" ainlif" and*" twalif"( meaning, respectively" one left" and" two left"), suggesting a decimal rather than duodecimal origin. However, Old Norse used a duodecimal counting system, with its words for" one hundred and eighty" meaning 200 and" two hundred" meaning 240. On British Isles, this style of counting survived well into the middle ages as the long hundred. Historically, units of time in many civilizations are duodecimal. There are twelve signs of the zodiac, twelve months in a year, and the Babylonians had twelve hours in a day( although at some point this was changed to 24). Traditional Chinese calendars, clocks, and compasses are based on the twelve Earthly Branches. There are 12 inches in an imperial foot, 12 troy ounces in a troy pound, 12 old British pence in a shilling, 24( 12× 2) hours in a day, and many other items counted by the dozen, gross( 144, square of 12), or great gross( 1728, cube of 12). The Romans used a fraction system based on 12, including the uncia which became both the English words" ounce" and" inch". Pre- decimalisation, Ireland and the United Kingdom used a mixed duodecimal- vigesimal currency system( 12 pence= 1 shilling, 20 shillings or 240 pence to the pound sterling or Irish pound), and Charlemagne established a monetary system that also had a mixed base of twelve and twenty, the remnants of which persist in many places. The importance of 12 has been attributed to the number of lunar cycles in a year as well as the fact that humans have 12 finger bones( phalanges) on one hand( three in each of four fingers). It is possible to count to 12 with the thumb acting as a pointer, touching each finger bone in turn. A traditional finger counting system still in use in many regions of Asia works in this way and could help to explain the occurrence of numeral systems based on 12 and 60 besides those based on 10, 20, and 5. In this system, the one( usually right) hand counts repeatedly to 12, displaying the number of iterations on the other( usually left), until five dozens, i. e. the 60, are full. Notations and pronunciations. Transdecimal symbols. In a numbering system the base( | twelve for duodecimal) must be |
written as 10, but there are numerous proposals for how to write duodecimal ten and eleven. To allow entry on typewriters, letters such as A and B( as in hexadecimal), T and E( initials of Ten and Eleven), X and E( X from the Roman numeral for ten), or X and Z are used. Some employ Greek letters such as δ( standing for Greek δέκα' ten') and ε( for Greek ένδεκα' eleven'), or τ and ε. Frank Emerson Andrews, an early American advocate for duodecimal, suggested and used in his book" New Numbers" an X and ℰ( script E,). Edna Kramer in her 1951 book" The Main Stream of Mathematics" used a six- pointed asterisk( sextile)⚹ and a hash( or octothorpe)#. The symbols were chosen because they were available on some typewriters; they are also on push- button telephones. This notation was used in publications of the Dozenal Society of America( DSA) from 1974– 2008. From 2008 to 2015, the DSA used and, the symbols devised by William Addison Dwiggins. The Dozenal Society of Great Britain( DSGB) proposed symbols and. This notation, derived from Arabic digits by 180° rotation, was introduced by Isaac Pitman. In March 2013, a proposal was submitted to include the digit forms for ten and eleven propagated by the Dozenal Societies in the Unicode Standard. Of these, the British/ Pitman forms were accepted for encoding as characters at code points and. They were included in the Unicode 8.0releaseinJune2015andareavailableinLaTeXascodice_1andcodice_2. After the Pitman digits were added to Unicode, the DSA took a vote and then began publishing content using the Pitman digits instead. They still use the letters X and E in ASCII text. As the Unicode characters are poorly supported, this page uses and. Other proposals are more creative or aesthetic; for example, many do not use any Arabic numerals under the principle of" separate identity." Base notation. There are also varying proposals of how to distinguish a duodecimal number from a decimal one. They include italicizing duodecimal numbers"" 54"= 64", adding a" Humphrey point"( a semicolon instead of a decimal point) to duodecimal numbers" 54; 6= 64. 5", or some combination of the two. Others use subscript or affixed labels to indicate the base, allowing for more than decimal and duodecimal to be represented( for single letters' z' from" dozenal" is used as' d' would mean decimal) such as"54z=64d,"" 5412= 6410" or" doz 54= dec 64." Pronunciation. The Dozenal Society of America suggested the pronunciation of ten and eleven as" dek" and" el". For the names of powers of twelve there are two prominent systems." Do- gro- mo" system. In this system, the prefix" e"- is added for fractions. Multiple digits in this series are pronounced differently: 12 is" do two"; 30 is" three do"; 100 is" gro"; 9 is" el gro dek do nine"; 86 is" el gro eight do six"; 8, 15 is" eight gro el do el, one gro five do dek"; and so on. Systematic Dozenal Nomenclature( SDN). This system uses"- qua" ending for the positive powers of 12 and"- cia" ending for the | negative powers of 12, and |
an extension of the IUPAC systematic element names( with syllables dec and lev for the two extra digits needed for duodecimal) to express which power is meant. Advocacy and" dozenalism". William James Sidis used 12 as the base for his constructed language Vendergood in 1906, noting it being the smallest number with four factors and its prevalence in commerce. The case for the duodecimal system was put forth at length in Frank Emerson Andrews' 1935 book" New Numbers: How Acceptance of a Duodecimal Base Would Simplify Mathematics". Emerson noted that, due to the prevalence of factors of twelve in many traditional units of weight and measure, many of the computational advantages claimed for the metric system could be realized" either" by the adoption of ten- based weights and measure" or" by the adoption of the duodecimal number system. Both the Dozenal Society of America and the Dozenal Society of Great Britain promote widespread adoption of the base- twelve system. They use the word" dozenal" instead of" duodecimal" to avoid the more overtly base- ten terminology. However, the etymology of" dozenal" itself is also an expression based on base- ten terminology since" dozen" is a direct derivation of the French word" douzaine" which is a derivative of the French word for twelve," douze", descended from Latin" duodecim". Since at least as far back as 1945 some members of the Dozenal Society of America and Dozenal Society of Great Britain have suggested that a more apt word would be" uncial". Uncial is a derivation of the Latin word" uncia", meaning" one- twelfth", and also the base- twelve analogue of the Latin word" decima", meaning" one- tenth". Mathematician and mental calculator Alexander Craig Aitken was an outspoken advocate of duodecimal: In media. In" Little Twelvetoes", American television series" Schoolhouse Rock!" portrayed an alien being using base- twelve arithmetic, using" dek"," el" and" doh" as names for ten, eleven and twelve, and Andrews' script- X and script- E for the digit symbols. Duodecimal systems of measurements. Systems of measurement proposed by dozenalists include: Comparison to other number systems. The number 12 has six factors, which are 1, 2, 3, 4, 6, and 12, of which 2 and 3 are prime. The decimal system has only four factors, which are 1, 2, 5, and 10, of which 2 and 5 are prime. Vigesimal( base 20) adds two factors to those of ten, namely 4 and 20, but no additional prime factor. Octodecimal( base 18) adds two factors to those of six, namely 9 and 18. Although twenty and eighteen has 6 factors, 2 of them prime, similarly to twelve, it is also a much larger base, and so the digit set and the multiplication table are much larger. Binary has only two factors, 1 and 2, the latter being prime. Hexadecimal( base 16) has five factors, adding 4, 8 and 16 to those of 2, but no additional prime. Sixteen has no odd factors, thus divisible only by power of 2, and it is also a much larger base, and so the digit set and the multiplication | table are much larger. Trigesimal( |
base 30) is the smallest system that has three different prime factors( all of the three smallest primes: 2, 3 and 5) and it has eight factors in total( 1, 2, 3, 5, 6, 10, 15, and 30). Sexagesimal— which the ancient Sumerians and Babylonians among others actually used— adds the four convenient factors 4, 12, 20, and 60 to this but no new prime factors. The smallest system that has four different prime factors is base 210 and the pattern follows the primorials. In all base systems, there are similarities to the representation of multiples of numbers which are one less than or one more than the base. Conversion tables to and from decimal. To convert numbers between bases, one can use the general conversion algorithm( see the relevant section under positional notation). Alternatively, one can use digit- conversion tables. The ones provided below can be used to convert any duodecimal number between 0; 01 and,; to decimal, or any decimal number between 0. 01 and 999, 999. 99 to duodecimal. To use them, the given number must first be decomposed into a sum of numbers with only one significant digit each. For example: This decomposition works the same no matter what base the number is expressed in. Just isolate each non- zero digit, padding them with as many zeros as necessary to preserve their respective place values. If the digits in the given number include zeroes( for example, 102, 304. 05), these are, of course, left out in the digit decomposition( 102, 304. 05= 100, 000+ 2, 000+ 300+ 4+ 0. 05). Then the digit conversion tables can be used to obtain the equivalent value in the target base for each digit. If the given number is in duodecimal and the target base is decimal, we get: Now, because the summands are already converted to base ten, the usual decimal arithmetic is used to perform the addition and recompose the number, arriving at the conversion result: Duodecimal-----& gt;Decimal100, 000= 248, 83220, 000= 41, 4723, 000= 5, 184400= 57650= 60+ 6=+ 60; 7= 0. 58333333333... 0; 08= 0. 05555555555... 123, 456; 78= 296, 130. 63888888888... That is, 123, 456. 78 equals 296, 130. 63≈ 296, 130.64If the given number is in decimal and the target base is duodecimal, the method is basically same. Using the digit conversion tables: 100, 000+ 20, 000+ 3, 000+ 400+ 50+ 6+ 0. 7+ 0. 08= 49, 54+, 68+ 1, 80+ 294+ 42+ 6+ 0; 84972497249724972497...+ 0; 062... However, in order to do this sum and recompose the number, now the addition tables for the duodecimal system have to be used, instead of the addition tables for decimal most people are already familiar with, because the summands are now in base twelve and so the arithmetic with them has to be in duodecimal as well. In decimal, 6+ 6 equals 12, but in duodecimal it equals 10; so, if using decimal arithmetic with duodecimal numbers one would arrive at an incorrect result. Doing the arithmetic properly in duodecimal, one gets the result: Decimal-----& gt;Duodecimal100, 000= 49, | 5420, 000=, 683, 000= 1, |
80400= 29450= 42+ 6=+ 60. 7= 0; 84972497249724972497... 0. 08= 0; 062... 123, 456. 78= 5, 540; 943... That is, 123, 456. 78 equals 5, 540; 9...≈ 5, 540;94Divisibility rules. This section is about the divisibility rules in duodecimal. Any integer is divisible by 1. If a number is divisible by 2 then the unit digit of that number will be 0, 2, 4, 6, 8 or. If a number is divisible by 3 then the unit digit of that number will be 0, 3, 6 or 9. If a number is divisible by 4 then the unit digit of that number will be 0, 4 or 8. To test for divisibility by 5, double the units digit and subtract the result from the number formed by the rest of the digits. If the result is divisible by 5 then the given number is divisible by 5. This rule comes from 21( 5* 5) Examples:& lt; br& gt; 13 rule=& gt;| 1- 2* 3|= 5 which is divisible by 5.& lt; br& gt; 25 rule=& gt;| 2- 2* 5|= 20( 5* 70) which is divisible by 5( or apply the rule on 20). To test for divisibility by 5, subtract the units digit and triple of the result to the number formed by the rest of the digits. If the result is divisible by 5 then the given number is divisible by 5. This rule comes from 13( 5* 3) Examples:& lt; br& gt; 13 rule=& gt;| 3- 3* 1|= 0 which is divisible by 5.& lt; br& gt; 25 rule=& gt;| 5- 3* 2|= 81( 5* 195) which is divisible by 5( or apply the rule on 81). Form the alternating sum of blocks of two from right to left. If the result is divisible by 5 then the given number is divisible by 5. This rule comes from 101, since 101= 5* 25, thus this rule can be also tested for the divisibility by 25. Example: 97, 374, 627=& gt; 27- 46+ 37- 97=- 7 which is divisible by 5. If a number is divisible by 6 then the unit digit of that number will be 0 or 6. To test for divisibility by 7, triple the units digit and add the result to the number formed by the rest of the digits. If the result is divisible by 7 then the given number is divisible by 7. This rule comes from 2( 7* 5) Examples:& lt; br& gt; 12 rule=& gt;| 3* 2+ 1|= 7 which is divisible by 7.& lt; br& gt; 271 rule=& gt;| 3*+ 271|= 29( 7* 4) which is divisible by 7( or apply the rule on 29). To test for divisibility by 7, subtract the units digit and double the result from the number formed by the rest of the digits. If the result is divisible by 7 then the given number is divisible by 7. This rule comes from 12( 7* 2) Examples:& lt; br& gt; 12 rule=& gt;| 2- 2* 1|= 0 which is divisible by 7.& lt; br& gt; 271 rule=& | gt;|- 2* 271|= 513( 7* |
89) which is divisible by 7( or apply the rule on 513). To test for divisibility by 7, 4 times the units digit and subtract the result from the number formed by the rest of the digits. If the result is divisible by 7 then the given number is divisible by 7. This rule comes from 41( 7* 7) Examples:& lt; br& gt; 12 rule=& gt;| 4* 2- 1|= 7 which is divisible by 7.& lt; br& gt; 271 rule=& gt;| 4*- 271|= 235( 7* 3) which is divisible by 7( or apply the rule on 235). Form the alternating sum of blocks of three from right to left. If the result is divisible by 7 then the given number is divisible by 7. This rule comes from 1001, since 1001= 7* 11* 17, thus this rule can be also tested for the divisibility by 11 and 17. Example: 386, 967, 443=& gt; 443- 967+ 386=- 168 which is divisible by 7. If the 2- digit number formed by the last 2 digits of the given number is divisible by 8 then the given number is divisible by 8. Example: 148,4120rule=& gt; since 48( 8* 7) divisible by 8, then 148 is divisible by 8. rule=& gt; since 20( 8* 3) divisible by 8, then 4120 is divisible by 8. If the 2- digit number formed by the last 2 digits of the given number is divisible by 9 then the given number is divisible by 9. Example: 7423,8330rule=& gt; since 23( 9* 3) divisible by 9, then 7423 is divisible by 9. rule=& gt; since 30( 9* 4) divisible by 9, then 8330 is divisible by 9. If the number is divisible by 2 and 5 then the number is divisible by. If the sum of the digits of a number is divisible by then the number is divisible by( the equivalent of casting out nines in decimal). Example: 29,6113rule=& gt; 2+ 9= which is divisible by, then 29 is divisible by. rule=& gt; 6+ 1++ 1+ 3= 1 which is divisible by, then 6113 is divisible by. If a number is divisible by 10 then the unit digit of that number will be 0. Sum the alternate digits and subtract the sums. If the result is divisible by 11 the number is divisible by 11( the equivalent of divisibility by eleven in decimal). Example: 66,9427rule=& gt;| 6- 6|= 0 which is divisible by 11, then 66 is divisible by 11. rule=& gt;|( 9+ 2)-( 4+ 7)|=|-|= 0 which is divisible by 11, then 9427 is divisible by 11. If the number is divisible by 2 and 7 then the number is divisible by 12. If the number is divisible by 3 and 5 then the number is divisible by 13. If the 2- digit number formed by the last 2 digits of the given number is divisible by 14 then the given number is divisible by 14. Example: 1468,7394rule=& gt; since 68( 14* 5) divisible by 14, then 1468 is divisible by 14. rule=& gt; since 94( 14* 7) divisible | by 14, then 7394 is |
divisible by 14. Fractions and irrational numbers. Fractions. Duodecimal fractions may be simple: or complicated: As explained in recurring decimals, whenever an irreducible fraction is written in radix point notation in any base, the fraction can be expressed exactly( terminates) if and only if all the prime factors of its denominator are also prime factors of the base. Thus, in decimal(= 2× 5) system, fractions whose denominators are made up solely of multiples of 2 and 5 terminate:=,= and= can be expressed exactly as 0. 125, 0. 05 and 0. 002 respectively. and, however, recur( 0. 333... and 0. 142857142857...). In the duodecimal(= 2× 2× 3) system, is exact; and recur because they include 5 as a factor; is exact; and recurs, just as it does in decimal. The number of denominators which give terminating fractions within a given number of digits, say" n", in a base" b" is the number of factors( divisors) of" bn", the" n" th power of the base" b"( although this includes the divisor 1, which does not produce fractions when used as the denominator). The number of factors of" bn" is given using its prime factorization. For decimal, 10" n"= 2" n"× 5" n". The number of divisors is found by adding one to each exponent of each prime and multiplying the resulting quantities together, so the number of factors of 10" n" is(" n"+ 1)(" n"+ 1)=(" n"+ 1) 2. For example, the number 8 is a factor of 103( 1000), so 1/ 8 and other fractions with a denominator of 8 cannot require more than 3 fractional decimal digits to terminate. 5/ 8= 0.62510For duodecimal, 10" n"= 22" n"× 3" n". This has( 2" n"+ 1)(" n"+ 1) divisors. The sample denominator of 8 is a factor of a gross( 122= 144 in decimal), so eighths cannot need more than two duodecimal fractional places to terminate. 5/ 8= 0.7612Because both ten and twelve have two unique prime factors, the number of divisors of" bn" for" b"= 10 or 12 grows quadratically with the exponent" n"( in other words, of the order of" n" 2). Recurring digits. The Dozenal Society of America argues that factors of 3 are more commonly encountered in real- life division problems than factors of 5. Thus, in practical applications, the nuisance of repeating decimals is encountered less often when duodecimal notation is used. Advocates of duodecimal systems argue that this is particularly true of financial calculations, in which the twelve months of the year often enter into calculations. However, when recurring fractions" do" occur in duodecimal notation, they are less likely to have a very short period than in decimal notation, because 12( twelve) is between two prime numbers, 11( eleven) and 13( thirteen), whereas ten is adjacent to the composite number 9. Nonetheless, having a shorter or longer period doesn' t help the main inconvenience that one does not get a finite representation for such fractions in the given base( so rounding, which introduces inexactitude, is necessary to handle them in calculations), and overall one is more likely to | have to deal with infinite |
recurring digits when fractions are expressed in decimal than in duodecimal, because one out of every three consecutive numbers contains the prime factor 3 in its factorization, whereas only one out of every five contains the prime factor 5. All other prime factors, except 2, are not shared by either ten or twelve, so they do notinfluence the relative likeliness of encountering recurring digits( any irreducible fraction that contains any of these other factors in its denominator will recur in either base). Also, the prime factor 2 appears twice in the factorization of twelve, whereas only once in the factorization of ten; which means that most fractions whose denominators are powers of two will have a shorter, more convenient terminating representation in duodecimal than in decimal: The duodecimal period length of 1/" n" are( in base 10) The duodecimal period length of 1/(" n" th prime) are( in base 10) Smallest prime with duodecimal period" n" are( in base 10) Irrational numbers. The representations of irrational numbers in any positional number system( including decimal and duodecimal) neither terminate nor repeat. The following table gives the first digits for some important algebraic and transcendental numbers in both decimal and duodecimal. David Hayes Agnew( November 24,1818March 22, 1892) was an American surgeon. Biography. Agnew was born on November 24, 1818, Nobleville, Pennsylvania( present- day Christiana). His parents were Robert Agnew and Agnes Noble. Agnew grew up as a Christian. He was surrounded by a family of doctors and had always known he was going to become a physician. As a young boy, he had a sharp sense of humor and was very intelligent. He was educated at Jefferson College, and at Delaware College in Newark, Delaware. He graduated from the University of Pennsylvania School of Medicine on April 6, 1838. He returned to Nobleville to help his father in his clinic. He worked there for two years. His father was an asthmatic and moved to Maryland in 1840 because the climate was more suited to his condition. Agnew moved with him. On November 21, 1841, he married Margaret Irwin. In 1852, he bought and revived the Philadelphia School of Anatomy. He held responsibility for ten years until 1862. During the American Civil War he was consulting surgeon in the Mower Army Hospital, near Philadelphia, and acquired a considerable reputation for his operations in cases of gunshot wounds. On December 21, 1863, he became the Demonstrator of Anatomy and Assistant Lecturer on Clinical Surgery at The University of Pennsylvania. Later, he was requested to assist the Professor of Surgery in the Conduct of the surgical clinics. In the year 1865, he gave summer instruction courses. For the next seven years, he worked for the University as Demonstrator of Anatomy. A large portion of his success was due to his wife' s energy, intelligence, and determination. She gave him an impetus to try harder and not be satisfied with his first try. He was elected as a member of the American Philosophical Society in 1872. Garfield case. On July 2, 1881, President James A. Garfield was | shot by Charles J. Guiteau. |
He held the position of chief consulting surgeon. When a committee came to give him his money for helping, Agnew said," Gentlemen, I present no bill for my attendance to President Garfield. I gave my services freely and gratuitously". He was never optimistic about the President' s case and was not fooled by fallacious beliefs. This procedure helped create Agnew' s reputation." The Agnew Clinic"." The Agnew Clinic" is an 1889 painting by Thomas Eakins which depicts Agnew conducting a mastectomy operation before a gallery of students and doctors. Accomplishments. David Agnew wrote" The Principles and Practice of Surgery", covers an experience of fifty active years, and its value, preserving and presenting as it does the life- work of such a recognized authority, can hardly be overrated. It was a three- volume set that he published from 1878– 1883. He also helped found the Irwin& amp; Agnew Iron Foundry in 1846. Death. Agnew caught a severe attack of epidemic influenza in 1890. He never fully recovered. Following this, he had an attack of broncho- vesicular catarrh. On March 9, 1892, he was put to bed for a series of medical problems. After a few days his condition began to improve, but suddenly, on March 12 it became much worse. On March 20, he fell into a comatose condition. Agnew stayed like this until he died at 3: 20 p. m. on March 22, 1892. He is now buried in West Laurel Hill Cemetery. References. CitationsSourcesDiving is the sport of jumping or falling into water from a platform or springboard, usually while performing acrobatics. Diving is an internationally recognized sport that is part of the Olympic Games. In addition, unstructured and non- competitive diving is a recreational pastime. Competitors possess many of the same characteristics as gymnasts and dancers, including strength, flexibility, kinaesthetic judgment and air awareness. Some professional divers were originally gymnasts or dancers as both the sports have similar characteristics to diving. Dmitri Sautin holds the record for most Olympic diving medals won, by winning eight medals in total between 1992 and 2008. History. Plunging. Although diving has been a popular pastime across the world since ancient times, the firstmoderndivingcompetitionswereheldinEnglandinthe1880s. The exact origins of the sport are unclear, though it likely derives from the act of diving at the start of swimming races. The 1904 book" Swimming" by Ralph Thomas notes English reports of plunging records dating back to at least 1865. The 1877 edition to" British Rural Sports" by John Henry Walsh makes note of a" Mr. Young" plunging in 1870, and also states that 25 years prior, a swimmer named Drake could cover. The English Amateur Swimming Association( at the time called the Swimming Association of Great Britain) first started a" plunging championship" in 1883. The Plunging Championship was discontinued in 1937. Fancy diving. Diving into a body of water had also been a method used by gymnasts in Germany and Sweden sincetheearly19th century. The soft landing allowed for more elaborate gymnastic feats in midair as the jump could be made from a greater height. This tradition evolved into' | fancy diving', while diving as |
a preliminary to swimming became known as' Plain diving'. In England, the practice of high diving– diving from a great height– gained popularity; the first diving stages were erected at the Highgate Ponds at a height of in 1893 and the first world championship event, the National Graceful Diving Competition, was held there by the Royal Life Saving Society in 1895. The event consisted of standing and running dives from either. It was at this event that the Swedish tradition of fancy diving was introduced to the sport by the athletes Otto Hagborg and C F Mauritzi.Theydemonstratedtheiracrobatictechniquesfromthe10m diving board at Highgate Pond and stimulated the establishment of the Amateur Diving Association in 1901, the first organization devoted to diving in the world( later amalgamated with the Amateur Swimming Association). Fancy diving was formally introduced into the championship in 1903. Olympic era. Plain diving was first introduced into the Olympics at the 1904 event. The 1908 Olympics in London added' fancy diving' and introduced elastic boards rather than fixed platforms. Women were first allowed to participate in the diving events for the 1912 Olympics in Stockholm. In the 1928 Olympics,' plain' and' fancy' diving were amalgamated into one event–' Highboard Diving'. The diving event was first held indoors in the Empire Pool for the 1934 British Empire Games and 1948 Summer Olympics in London. Competitive diving. Most diving competitions consist of three disciplines: 1 m and 3 m springboards, and the platform. Competitive athletes are divided by gender, and often by age group. In platform events, competitors are allowed to perform their dives on either the five, seven and a half( generally just called seven), nine, or ten meter towers. In major diving meets, including the Olympic Games and the World Championships, platform diving is from the 10 meter height. Divers have to perform a set number of dives according to established requirements, including somersaults and twists. Divers are judged on whether and how well they completed all aspects of the dive, the conformance of their body to the requirements of the dive, and the amount of splash created by their entry to the water. A possible score out of ten is broken down into three points for the takeoff( meaning the hurdle), three for the flight( the actual dive), and three for the entry( how the diver hits the water), with one more available to give the judges flexibility. The raw score is multiplied by a degree of difficulty factor, derived from the number and combination of movements attempted. The diver with the highest total score after a sequence of dives is declared the winner. Synchronized diving. Synchronized diving was adopted as an Olympic sport in 2000. Two divers form a team and perform dives simultaneously. The dives are identical. It used to be possible to dive opposites, also known as a pinwheel, but this is no longer part of competitive synchronized diving. For example, one diver would perform a forward dive and the other an inward dive in the same position, or one would do a reverse and the other a | back movement. In these events, |
the diving would be judged both on the quality of execution and the synchronicity– in timing of take- off and entry, height and forward travel. Scoring the dive. There are rules governing the scoring of a dive. Usually a score considers three elements of the dive: the approach, the flight, and the entry. The primary factors affecting the scoring are: Each dive is assigned a" degree of difficulty"( DD), which is determined from a combination of the moves undertaken, position used, and height. The DD value is multiplied by the scores given by the judges. To reduce the subjectivity of scoring in major meets, panels of five or seven judges are assembled; major international events such as the Olympics use seven- judge panels. For a five- judge panel, the highest and lowest scores are discarded and the middle three are summed and multiplied by the DD. For seven- judge panels, as of the 2012 London Olympics, the two highest scores and two lowest are discarded, leaving three to be summed and multiplied by the DD.( Prior to the London Olympics, the highest and lowest scores were eliminated, and the remaining five scores were multiplied by, to allow for comparison to five- judge panels.) The canceling of scores is used to make it difficult for a single judge to manipulate scores. There is a general misconception about scoring and judging. In serious meets, the absolute score is somewhat meaningless. It is the relative score, not the absolute score that wins meets. Accordingly, good judging implies consistent scoring across the dives. Specifically, if a judge consistently gives low scores for all divers, or consistently gives high scores for the same divers, the judging will yield fair relative results and will cause divers to place in the correct order. However, absolute scores have significance to the individual divers. Besides the obvious instances of setting records, absolute scores are also used for rankings and qualifications for higher level meets. In synchronised diving events, there is a panel of seven, nine, or eleven judges; two or three to mark the execution of one diver, two or three to mark the execution of the other, and the remaining three or five to judge the synchronisation. The execution judges are positioned two on each side of the pool, and they score the diver which is nearer to them. The 2012 London Olympics saw the first use of eleven judges. The score is computed similarly to the scores from other diving events, but has been modified starting with the 2012 London Olympics for the use of the larger judging panels. Each group of judges will have the highest and lowest scores dropped, leaving the middle score for each diver' s execution and the three middle scores for synchronization. The total is then weighted by and multiplied by the DD. The result is that the emphasis is on the synchronization of the divers. The synchronisation scores are based on: The judges may also disqualify the diver for certain violations during the dive, including: Competitive strategy. To win dive meets, divers create | a dive list in advance |
of the meet. To win the meet the diver must accumulate more points than other divers. Often, simple dives with low DDs will look good to spectators but will not win meets. The competitive diver will attempt the highest DD dives possible with which they can achieve consistent, high scores. If divers are scoring 8 or 9 on most dives, it may be a sign of their extreme skill, or it may be a sign that their dive list is not competitive, and they may lose the meet to a diver with higher DDs and lower scores. In competition, divers must submit their lists beforehand, and once past a deadline( usually when the event is announced or shortly before it begins) they cannot change their dives. If they fail to perform the dive announced, even if they physically cannot execute the dive announced or if they perform a more difficult dive, they will receive a score of zero. Under exceptional circumstances, a redive may be granted, but these are exceedingly rare( usually for very young divers just learning how to compete, or if some event outside the diver' s control has caused them to be unable to perform- such as a loud noise). In the Olympics or other highly competitive meets, many divers will have nearly the same list of dives as their competitors. The importance for divers competing at this level is not so much the DD, but how they arrange their list. Once the more difficult rounds of dives begin it is important to lead off with a confident dive to build momentum. They also tend to put a very confident dive in front of a very difficult dive to ensure that they will have a good mentality for the difficult dive. Most divers have pre- dive and post- dive rituals that help them either maintain or regain focus. Coaches also play a role in this aspect of the sport. Many divers rely on their coaches to help keep their composure during the meet. In a large meet coaches are rarely allowed on the deck to talk to their athlete so it is common to see coaches using hand gestures or body movements to communicate. There are some American meets which will allow changes of the position of the dive even after the dive has been announced immediately before execution, but these are an exception to the rules generally observed internationally. Generally, NCAA rules allow for dives to be changed while the diver is on the board, but the diver must request the change directly after the dive is announced. This applies especially in cases where the wrong dive is announced. If the diver pauses during his or her hurdle to ask for a change of dive, it will be declared a balk( when the diver stops mid- hurdle) and the change of dive will not be permitted. Under FINA law, no dive may be changed after the deadline for the dive- sheet to be submitted( generally a period ranging from one hour to 24 hours, depending on the rulings | made by the event organiser). |
It is the diver' s responsibility to ensure that the dive- sheet is filled in correctly, and also to correct the referee or announcer before the dive if they describe it incorrectly. If a dive is performed which is as submitted but not as( incorrectly) announced, it is declared failed and scores zero according to a strict reading of the FINA law. But in practice, a re- dive would usually be granted in these circumstances. Governance. The global governing body of diving is FINA, which also governs swimming, synchronised swimming, water polo and open water swimming. Almost invariably, at national level, diving shares a governing body with the other aquatic sports. This is frequently a source of political friction as the committees are naturally dominated by swimming officials who do not necessarily share or understand the concerns of the diving community. Divers often feel, for example, that they do not get adequate support over issues like the provision of facilities. Other areas of concern are the selection of personnel for the specialised Diving committees and for coaching and officiating at events, and the team selection for international competitions. There are sometimes attempts to separate the governing body as a means to resolve these frustrations, but they are rarely successful. For example, in the UK the Great Britain Diving Federation was formed in 1992 with the intention of taking over the governance of Diving from the ASA( Amateur Swimming Association). Although it initially received widespread support from the diving community, the FINA requirement that international competitors had to be registered with their National Governing Body was a major factor in the abandonment of this ambition a few years later. Since FINA refused to rescind recognition of the ASA as the British governing body for all aquatic sports including diving, this meant that the elite divers had to belong to ASA- affiliated clubs to be eligible for selection to international competition. In the United States scholastic diving is almost always part of the school' s swim team. Diving is a separate sport in Olympic and Club Diving. The NCAA will separate diving from swimming in special diving competitions after the swim season is completed. Safety. Despite the apparent risk, the statistical incidence of injury in supervised training and competition is extremely low. The majority of accidents that are classified as' diving- related' are incidents caused by individuals jumping from structures such as bridges or piers into water of inadequate depth. Many accidents also occur when divers do not account for rocks and logs in the water. Because of this many beaches and pools prohibit diving in shallow waters or when a lifeguard is not on duty. After an incident in Washington in 1993, most US and other pool builders are reluctant to equip a residential swimming pool with a diving springboard so home diving pools are much less common these days. In the incident, 14- year- old Shawn Meneely made a" suicide dive"( holding his hands at his sides, so that his head hit the bottom first) in a private swimming pool and became | a tetraplegic. The lawyers for |
the family, Jan Eric Peterson and Fred Zeder, successfully sued the diving board manufacturer, the pool builder, and the National Spa and Pool Institute over the inappropriate depth of the pool. The NSPI had specified a minimum depth of 7 ft 6 in( 2. 29 m) which proved to be insufficient in the above case. The pool into which Meneely dived was not constructed to the published standards. The standards had changed after the diving board was installed on the non- compliant pool by the homeowner. But the courts held that the pool" was close enough" to the standards to hold NSPI liable. The multimillion- dollar lawsuit was eventually resolved in 2001 for US$ 6. 6 million($ 8 million after interest was added) in favor of the plaintiff. The NSPI was held to be liable, and was financially strained by the case. It filed twice for Chapter 11 bankruptcy protection and was successfully reorganized into a new swimming pool industry association. In competitive diving, FINA takes regulatory steps to ensure that athletes are protected from the inherent dangers of the sport. For example, they impose restrictions according to age on the heights of platforms which divers may compete on. Group D divers have only recently been allowed to compete on the tower. In the past, the age group could compete only springboard, to discourage children from taking on the greater risks of tower diving. Group D tower was introduced to counteract the phenomenon of coaches pushing young divers to compete in higher age categories, thus putting them at even greater risk. However, some divers may safely dive in higher age categories to dive on higher platforms. Usually this occurs when advanced Group C divers wish to compete on the 10 m. Points on pool depths in connection with safety: Dive groups. There are six" groups" into which dives are classified:" Forward, Back, Inward, Reverse, Twist," and" Armstand". The armstand group applies only to Platform competitions, whereas the other five groups apply to both Springboard and Platform. Dive positions. During the flight of the dive, one of four positions is assumed: These positions are referred to by the letters A, B, C and D respectively. Additionally, some dives can be started in a flying position. The body is kept straight with the arms extended to the side, and the regular dive position is assumed at about half the dive. Difficulty is rated according to the Degree of Difficulty of the dives. Some divers may find pike easier in a flip than tuck, and most find straight the easiest in a front/ back dive, although it is still rated the most difficult because of the risk of overrotation. An armstand dive may have a higher degree of difficulty outdoors compared to indoors as wind can destabilize the equilibrium of the diver. Dive numbers. In competition, the dives are referred to by a schematic system of three- or four- digit numbers. The letter to indicate the position is appended to the end of the number. The first digit of the number indicates the dive group | as defined above. For groups |
1 to 4, the number consists of three digits and a letter of the alphabet. The third digit represents the number of half- somersaults. The second digit is either 0 or 1, with 0 representing a normal somersault, and 1 signifying a" flying" variation of the basic movement( i. e. the first half somersault is performed in the straight position, and then the pike or tuck shape is assumed). No flying dive has been competed at a high level competition for many years. For example: For Group 5, the dive number has 4 digits. The first digit indicates that it is a twisting dive. The second digit indicates the group( 1– 4) of the underlying movement; the third digit indicates the number of half- somersaults, and the fourth indicates the number of half- twists. For example: For Group 6– Armstand– the dive number has either three or four digits: Three digits for dives without twist and four for dives with twists. In non- twisting armstand dives, the second digit indicates the direction of rotation( 0= no rotation, 1= forward, 2= backward, 3= reverse, 4= inward) and the third digit indicates the number of half- somersaults. Inward- rotating armstand dives have never been performed, and are generally regarded as physically impossible. For example: For twisting Armstand dives, the dive number again has 4 digits, but rather than beginning with the number 5, the number 6 remains as the first digit, indicating that the" twister" will be performed from an Armstand. The second digit indicates the direction of rotation– as above, the third is the number of half- somersaults, and the fourth is the number of half- twists: e. g.6243D– armstand back double- somersault with one and a half twists in the free positionAll of these dives come with DD( degree of difficulty) this is an indication of how difficult/ complex a dive is. The score that the dive receives is multiplied by the DD( also known as tariff) to give the dive a final score. Before a diver competes they must decide on a" list" this is a number of optional dives and compulsory dives. The optionals come with a DD limit. this means that a diver must select X number of dives and the combined DD limit must be no more than the limit set by the competition/ organisation etc. Until the mid-1990s the tariff was decided by the FINA diving committee, and divers could only select from the range of dives in the published tariff table. Since then, the tariff is calculated by a formula based on various factors such as the number of twist and somersaults, the height, the group etc., and divers are free to submit new combinations. This change was implemented because new dives were being invented too frequently for an annual meeting to accommodate the progress of the sport. Mechanics of diving. At the moment of take- off, two critical aspects of the dive are determined, and cannot subsequently be altered during the execution. One is the trajectory of the dive, and the other is the magnitude | of the angular momentum. The |
speed of rotation– and therefore the total amount of rotation– may be varied from moment to moment by changing the shape of the body, in accordance with the law of conservation of angular momentum. The center of mass of the diver follows a parabolic path in free- fall under the influence of gravity( ignoring the effects of air resistance, which are negligible at the speeds involved). Trajectory. Since the parabola is symmetrical, the travel away from the board as the diver passes it is twice the amount of the forward travel at the peak of the flight. Excessive forward distance to the entry point is penalized when scoring a dive, but obviously an adequate clearance from the diving board is essential on safety grounds. The greatest possible height that can be achieved is desirable for several reasons: Control of rotation. The magnitude of angular momentum remains constant throughout the dive, but sinceand the moment of inertia is larger when the body has an increased radius, the speed of rotation may be increased by moving the body into a compact shape, and reduced by opening out into a straight position. Since the tucked shape is the most compact, it gives the most control over rotational speed, and dives in this position are easier to perform. Dives in the straight position are hardest, since there is almost no scope for altering the speed, so the angular momentum must be created at take- off with a very high degree of accuracy.( A small amount of control is available by moving the position of the arms and by a slight hollowing of the back). The opening of the body for the entry does not stop the rotation, but merely slows it down. The vertical entry achieved by expert divers is largely an illusion created by starting the entry slightly short of vertical, so that the legs are vertical as they disappear beneath the surface. A small amount of additional tuning is available by' entry save' techniques, whereby underwater movements of the upper body and arms against the viscosity of the water affect the position of the legs. Twisting. Dives with multiple twists and somersaults are some of the most spectacular movements, as well as the most challenging to perform. The rules state that twisting' must not be generated manifestly on take- off'. Consequently, divers must use some of the somersaulting angular momentum to generate twisting movements. The physics of twisting can be explained by looking at the components of the angular momentum vector. As the diver leaves the board, the total angular momentum vector is horizontal, pointing directly to the left for a forward dive for example. For twisting rotation to exist, it is necessary to tilt the body sideways after takeoff, so that there is now a small component of this horizontal angular momentum vector along the body' s long axis. The tilt can be seen in the photo. The tilting is done by the arms, which are outstretched to the sides just before the twist. When one arm is moved up and the other | is moved down( like turning |
a big steering wheel), the body reacts by tilting to the side, which then begins the twisting rotation. At the completion of the required number of twist rotations, the arm motion is reversed( the steering wheel is turned back), which removes the body' s tilt and stops the twisting rotation. An alternative explanation is that the moving arms have precession torque on them which set the body into twisting rotation. Moving the arms back produces opposite torque which stops the twisting rotation. Entry. The rules state that the body should be vertical, or nearly so, for entry. Strictly speaking, it is physically impossible to achieve a literally vertical position throughout the entry as there will inevitably still be some rotational momentum while the body is entering the water. Divers therefore attempt to create the illusion of being vertical, especially when performing rapidly rotating multiple somersault movements. For back entries, one technique is to allow the upper body to enter slightly short of vertical so that the continuing rotation leaves the final impression of the legs entering vertically. This is called" Pike save". Another is to use" knee save" movements of scooping the upper body underwater in the direction of rotation so as to counteract the rotation of the legs. The arms must be beside the body for feet- first dives,whicharetypicallycompetedonlyonthe1mspringboardandonlyatfairlylowlevelsof3m springboard, and extended forwards in line for" head- first" dives, which are much more common competitively. It used to be common for the hands to be interlocked with the fingers extended towards the water, but a different technique has become favoured during the last few decades. Now the usual practice is for one hand to grasp the other with palms down to strike the water with a flat surface. This creates a vacuum between the hands, arms and head which, with a vertical entry, will pull down and under any splash until deep enough to have minimal effect on the surface of the water( the so- called" rip entry"). Once a diver is completely under the water they may choose to roll or scoop in the same direction their dive was rotating to pull their legs into a more vertical position. Apart from aesthetic considerations, it is important from a safety point of view that divers reinforce the habit of rolling in the direction of rotation, especially for forward and inward entries. Back injuries such as hyperextension are caused by attempting to re- surface in the opposite direction. Diving from the higher levels increases the danger and likelihood of such injuries. By country. Canada. In Canada, elite competitive diving is regulated by DPC( Diving Plongeon Canada), although the individual provinces also have organizational bodies. The main competitive season runs from February to July, although some competitions may be held in January or December, and many divers( particularly international level athletes) will train and compete year round. Most provincial level competitions consist of events for 6 age groups( Groups A, B, C, D, E, and Open) for both genders on each of the three board levels. These age groups roughly correspond to those | standardized by FINA, with the |
addition of a youngest age group for divers 9 and younger, Group E, which does not compete nationally and does not have a tower event( although divers of this age may choose to compete in Group D). The age group Open is so called because divers of any age, including those over 18, may compete in these events, so long as their dives meet a minimum standard of difficulty. Although Canada is internationally a fairly strong country in diving, the vast majority of Canadian high schools and universities do not have diving teams, and many Canadian divers accept athletic scholarships from American colleges. Adult divers who are not competitive at an elite level may compete in masters diving. Typically, masters are either adults who never practiced the sport as children or teenagers, or former elite athletes who have retired but still seek a way to be involved in the sport. Many diving clubs have masters teams in addition to their primary competitive ones, and while some masters dive only for fun and fitness, there are also masters competitions, which range from the local to world championship level. National championships. Divers can qualify to compete at the age group national championships, or junior national championships, in their age groups as assigned by FINA up to the age of 18. This competition is held annually in July. Qualification is based on achieving minimum scores at earlier competitions in the season, although athletes who place very highly at a national championship will be automatically qualified to compete at the next. Divers must qualify at two different competitions, at least one of which must be a level 1 competition, i. e. a competition with fairly strict judging patterns. Such competitions include the Polar Bear Invitational in Winnipeg, the Sting in Victoria, and the Alberta Provincial Championships in Edmonton or Calgary. The qualifying scores are determined by DPC according to the results of the preceding year' s national competition, and typically do not have much variation from year to year. Divers older than 18, or advanced divers of younger ages, can qualify for the senior national championships, which are held twice each year, once roughly in March and once in June or July. Once again, qualification is based on achieving minimum scores at earlier competitions( in this case, within the 12 months preceding the national championships, and in an Open age group event), or high placements in previous national championships or international competitions. It is no longer the case that divers may use results from age group events to qualify for senior nationals, or results from Open events to qualify for age group nationals. Republic of Ireland. In the Republic of Ireland facilities are limited to one pool at the National Aquatic Centre in Dublin. National championships. National championships take place late in the year, usually during November. The competition is held at the National Aquatic Centre in Dublin and consists of four events: United Kingdom. In the United Kingdom, diving competitions on all boards run throughout the year. National Masters' Championships are held two or three | times per year. United States. |
Summer diving. In the United States, summer diving is usually limited to one meter diving at community or country club pools. Some pools organize to form intra- pool competitions. These competitions are usually designed to accommodate all school- age children. High school diving. In the United States scholastic diving at the high school level is usually limited to one meter diving( but some schools use three meter springboards.). Scores from those one meter dives contribute to the swim team' s overall score. High school diving and swimming concludes their season with a state competition. Depending on the state and the number of athletes competing in the state, certain qualifications must be achieved to compete in the state' s championship meet. There are often regional championships and district championships which are necessary to compete in before reaching the state meet to narrow the field to only the most competitive athletes. Most state championship meets consist of eleven dives. The eleven dives are usually split up between two categories: five required( voluntary) dives and six optional dives. Club diving. In the United States, pre- college divers interested in learning one and three meter or platform diving should consider a club sanctioned by either USA Diving or AAU Diving. In USA Diving, Future Champions is the entry level or novice diver category with 8 levels of competition. From Future Champions, divers graduate to" Junior Olympic", or JO. JO divers compete in age groups at inter- club competitions, at invitationals, and if qualified, at regional, zone and national competitions. Divers over the age of 19 years of age cannot compete in these events as a JO diver. USA Diving sanctions the Winter Nationals championship with one, three meter, and platform events. In the summer USA Diving sanctions the Summer Nationals including all three events with both Junior and Senior divers. USA Diving is sanctioned by the United States Olympic Committee to select team representatives for international diving competitions including the World Championships and Olympic Games. AAU Diving sanctions one national event per year in the summer. AAU competes on the one, three, and tower to determine the All- American team. College diving. In the United States scholastic diving at the college level requires one and three meter diving. Scores from the one and three meter competition contribute to the swim team' s overall meet score. College divers interested in tower diving may compete in the NCAA separate from swim team events. NCAA Divisions II and III do not usually compete platform; if a diver wishes to compete platform in college, he or she must attend a Division I school. Each division also has rules on the number of dives in each competition. Division II schools compete with 10 dives in competition whereas Division III schools compete with 11. Division I schools only compete with 6 dives in competition. These 6 dives consist of either 5 optionals and 1 voluntary, or 6 optionals. If the meet is a 5 optional meet, then the divers will perform 1 optional from each category( Front, Back, Inward, Reverse, and Twister) | and then 1 voluntary from |
the category of their choice. The voluntary in this type of meet is always worth a DD( Degree of Difficulty) of 2. 0 even if the real DD is worth more or less on a DD sheet. In a 6 optional meet, the divers will yet again perform one dive from each category,butthistimetheywillperforma6th optional from the category of their choosing, which is worth its actual DD from the DD sheet. The highest level of collegiate competition is the NCAA Division 1 Swimming and Diving Championship. Events at the championship include 1 meter springboard, 3 meter springboard, and platform, as well as various swimming individual and relay events. The points scored by swimmers and divers are combined to determine a team swimming& amp; diving champion. To qualify for a diving event at the NCAA championships, a competitor must first finish in the top three at one of five zone championships, which are held after the various conference championship meets. A diver who scores at least 310 points on the 3 meter springboard and 300 points on the 1 meter springboard in a 6 optional meet can participate in the particular zone championship corresponding to the geographic region in which his or her school lies. A number of colleges and universities offer scholarships to men and women who have competitive diving skills. These scholarships are usually offered to divers with age- group or club diving experience. The NCAA limits the number of years a college student can represent any school in competitions. The limit is four years, but could be less under certain circumstances. Masters' Diving. Divers who continue diving past their college years can compete in Masters' Diving programs. Masters' diving programs are frequently offered by college or club programs. Masters' Diving events are normally conducted in age- groups separated by five or ten years, and attract competitors of a wide range of ages and experience( many, indeed, are newcomers to the sport); the oldest competitor in a Masters' Diving Championship was Viola Krahn, who at the age of 101 was the first person in any sport, male or female, anywhere in the world, to compete in an age- group of 100+ years in a nationally organized competition. Non- competitive diving. Diving is also popular as a non- competitive activity. Such diving usually emphasizes the airborne experience, and the height of the dive, but does not emphasize what goes on once the diver enters the water. The ability to dive underwater can be a useful emergency skill, and is an important part of watersport and navy safety training. Entering water from a height is an enjoyable leisure activity, as is underwater swimming. Such non- competitive diving can occur indoors and outdoors. Outdoor diving typically takes place from cliffs or other rock formations either into fresh or salt water. However, man- made diving platforms are sometimes constructed in popular swimming destinations. Outdoor diving requires knowledge of the water depth and currents as conditions can be dangerous. On occasion, the diver will inadvertently belly flop, entering the water horizontally or nearly so. The diver typically | displaces a larger than usual |
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