91-731: For Misplaced Pages's policy on primary sources , see Misplaced Pages:No original research § Primary . [REDACTED] Look up primary in Wiktionary, the free dictionary. Primary or primaries may refer to: Arts, entertainment, and media [ edit ] Music [ edit ] Groups and labels [ edit ] Primary (band) , from Australia Primary (musician) , hip hop musician and record producer from South Korea Primary Music , Israeli record label Works [ edit ] Primary (album) by Rubicon (2002) "Primary" (song) by The Cure "Primary", song by Spoon from
182-476: A memoir would be considered a primary source in research concerning its author or about their friends characterized within it, but the same memoir would be a secondary source if it were used to examine the culture in which its author lived. "Primary" and "secondary" should be understood as relative terms, with sources categorized according to specific historical contexts and what is being studied. In scholarly writing, an important objective of classifying sources
273-410: A biography of a historian, that historian's publications would be primary sources. Documentary films can be considered a secondary source or primary source, depending on how much the filmmaker modifies the original sources. The Lafayette College Library provides a synopsis of primary sources in several areas of study: The definition of a primary source varies depending upon the academic discipline and
364-419: A broader sense primary sources also include artifacts like photographs, newsreels, coins, paintings or buildings created at the time. Historians may also take archaeological artifacts and oral reports and interviews into consideration. Written sources may be divided into three types. In historiography, when the study of history is subject to historical scrutiny, a secondary source becomes a primary source. For
455-453: A certain topic. Whether a source is regarded as primary or secondary in a given context may change, depending upon the present state of knowledge within the field. For example, if a document refers to the contents of a previous but undiscovered letter, that document may be considered "primary", since it is the closest known thing to an original source; but if the letter is later found, it may then be considered "secondary" In some instances,
546-442: A clear trilling courtship call. A curve-tipped secondary on each wing is dragged against an adjacent ridged secondary at high speeds (as many as 110 times per second—slightly faster than a hummingbird's wingbeat) to create a stridulation much like that produced by some insects. Both Wilson's and common snipe have modified outer tail feathers which make noise when they are spread during the birds' roller coaster display flights; as
637-411: A court case may be truthful but may still be distorted to support or oppose the position of one of the parties. Many sources can be considered either primary or secondary, depending on the context in which they are examined. Moreover, the distinction between primary and secondary sources is subjective and contextual, so that precise definitions are difficult to make. A book review, when it contains
728-481: A disease that is due to a root cause of illness Christian Science practitioner#Primary class instruction See also [ edit ] Binary (disambiguation) Primary group (disambiguation) Second (disambiguation) Unary (disambiguation) All pages with titles beginning with Primary All pages with titles containing Primary Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
819-511: A large extent in size and shape (except in the case of mutation or damage), though not necessarily in the pattern. They are given different names depending on their position along the wing. Primaries are connected to the manus (the bird's "hand", composed of carpometacarpus and phalanges ); these are the longest and narrowest of the remiges (particularly those attached to the phalanges), and they can be individually rotated. These feathers are especially important for flapping flight, as they are
910-528: A more protracted moult. In many species, there is more than one focus along the wing. Here, moult begins at all foci simultaneously, but generally proceeds only in one direction. Most grouse, for example, have two wing foci: one at the wingtip, the other between feathers P1 and S1. In this case, moult proceeds descendantly from both foci. Many large, long-winged birds have multiple wing foci. Birds that are heavily "wing-loaded"—that is, heavy-bodied birds with relatively short wings—have great difficulty flying with
1001-444: A narrative that may not be accurate. For any source, primary or secondary, it is important for the researcher to evaluate the amount and direction of bias. As an example, a government report may be an accurate and unbiased description of events, but it may be censored or altered for propaganda or cover-up purposes. The facts can be distorted to present the opposing sides in a negative light. Barristers are taught that evidence in
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#17327661073091092-408: A primary source can be a person with direct knowledge of a situation, or a document written by such a person. Primary sources are distinguished from secondary sources , which cite, comment on, or build upon primary sources. Generally, accounts written after the fact with the benefit of hindsight are secondary. A secondary source may also be a primary source depending on how it is used. For example,
1183-471: A primary source is not necessarily more of an authority or better than a secondary source. There can be bias and tacit unconscious views that twist historical information. Original material may be... prejudiced, or at least not exactly what it claims to be. The errors may be corrected in secondary sources, which are often subjected to peer review , can be well documented, and are often written by historians working in institutions where methodological accuracy
1274-656: A primary source was perpetrated by Sir Edward Dering , who placed false monumental brasses in a parish church . In 1986, Hugh Trevor-Roper authenticated the Hitler Diaries , which were later proved to be forgeries. Recently , forged documents have been placed within the UK National Archives in the hope of establishing a false provenance . However, historians dealing with recent centuries rarely encounter forgeries of any importance. Primary feathers Flight feathers ( Pennae volatus ) are
1365-498: A prime number Politics [ edit ] Primary elections or primaries, elections held to determine which candidates will run for an upcoming general election Primary vote, the total of first-preference votes in the Australian electoral system Science and mechanics [ edit ] Primary (astronomy) , the larger of two co-orbiting bodies Primary (chemistry) , term used in organic chemistry Primary,
1456-501: A sound during territorial or courtship displays. Over time, a small number of bird species have lost their ability to fly. Some of these, such as the steamer ducks , show no appreciable changes in their flight feathers. Some, such as the Titicaca grebe and a number of the flightless rails, have a reduced number of primaries. The remiges of ratites are soft and downy; they lack the interlocking hooks and barbules that help to stiffen
1547-433: A state known as diastataxis (those that do have the fifth secondary are said to be eutaxic). In these birds, the fifth set of secondary covert feathers does not cover any remiges, possibly due to a twisting of the feather papillae during embryonic development. Loons , grebes, pelicans , hawks and eagles , cranes , sandpipers , gulls , parrots, and owls are among the families missing this feather. Tertials arise in
1638-544: A summary of a book or letter has survived. Potential difficulties with primary sources have the result that history is usually taught in schools using secondary sources. Historians studying the modern period with the intention of publishing an academic article prefer to go back to available primary sources and to seek new (in other words, forgotten or lost) ones. Primary sources, whether accurate or not, offer new input into historical questions and most modern history revolves around heavy use of archives and special collections for
1729-458: A transformer Primary feathers , flight feathers attached to the manus ("hand") in the wings of birds Primary color Other uses [ edit ] Primary (LDS Church) , a children's Sunday School organization Primary (musician) (born 1983), South Korean Primary data (or raw data), a term for data collected from a source Primary Flight Training , in the U.S. Navy Primary source , original materials Primary disease ,
1820-457: Is also found, though to a lesser extent, in some other species that feed along tree trunks, including treecreepers and woodcreepers . Scientists have not yet determined the function of all flight feather modifications. Male swallows in the genera Psalidoprocne and Stelgidopteryx have tiny recurved hooks on the leading edges of their outer primaries, but the function of these hooks is not yet known; some authorities suggest they may produce
1911-437: Is based on primary sources, as evaluated by the community of scholars, who report their findings in books, articles, and papers. Arthur Marwick says "Primary sources are absolutely fundamental to history." Ideally, a historian will use all available primary sources that were created by the people involved at the time being studied. In practice, some sources have been destroyed, while others are not available for research. Perhaps
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#17327661073092002-453: Is called diplomatics . For centuries, popes used the forged Donation of Constantine to bolster the Papacy's secular power. Among the earliest forgeries are false Anglo-Saxon charters , a number of 11th- and 12th-century forgeries produced by monasteries and abbeys to support a claim to land where the original document had been lost or never existed. One particularly unusual forgery of
2093-531: Is called saltatory or transilient wing moults. In simple forms, this involves the moulting and replacement of odd-numbered primaries and then the even-numbered primaries. There are however complex variations with differences based on life history. Arboreal woodpeckers , which depend on their tails—particularly the strong central pair of rectrices—for support while they feed, have a unique tail moult. Rather than moulting their central tail feathers first, as most birds do, they retain these feathers until last. Instead,
2184-493: Is diminished when the outer primaries are worn, and absent when those feathers have been moulted. During the northern lapwing 's zigzagging display flight, the bird's outer primaries produce a humming sound. The outer primaries of the male American woodcock are shorter and slightly narrower than those of the female, and are likely the source of the whistling and twittering sounds made during his courtship display flights. Male club-winged manakins use modified secondaries to make
2275-645: Is important to the future of the author's career and reputation. Historians consider the accuracy and objectivity of the primary sources that they are using and historians subject both primary and secondary sources to a high level of scrutiny. A primary source such as a journal entry (or the online version, a blog), at best, may only reflect one individual's opinion on events, which may or may not be truthful, accurate, or complete. Participants and eyewitnesses may misunderstand events or distort their reports, deliberately or not, to enhance their own image or importance. Such effects can increase over time, as people create
2366-473: Is known as moult (molt in the United States). The loss of wing and tail feathers can affect a bird's ability to fly (sometimes dramatically) and in certain families can impair the ability to feed or perform courtship displays . The timing and progression of flight feather moult therefore varies among families. For most birds, moult begins at a certain specific point, called a focus (plural foci), on
2457-660: Is moulted at a different time. The flight feathers of adults and juveniles can differ considerably in length, particularly among the raptors. Juveniles tend to have slightly longer rectrices and shorter, broader wings (with shorter outer primaries, and longer inner primaries and secondaries) than do adults of the same species. However, there are many exceptions. In longer-tailed species, such as swallow-tailed kite , secretary bird and European honey buzzard , for example, juveniles have shorter rectrices than adults do. Juveniles of some Buteo buzzards have narrower wings than adults do, while those of large juvenile falcons are longer. It
2548-459: Is only with great caution that [the author] may proceed to make use of secondary sources." In addition, primary sources avoid the problem inherent in secondary sources in which each new author may distort and put a new spin on the findings of prior cited authors. A history, whose author draws conclusions from other than primary sources or secondary sources actually based on primary sources, is by definition fiction and not history at all. However,
2639-437: Is passed from one author to another. In scientific literature , a primary source, or the "primary literature", is the original publication of a scientist's new data, results, and theories. In political history , primary sources are documents such as official reports, speeches, pamphlets, posters, or letters by participants, official election returns, and eyewitness accounts. In the history of ideas or intellectual history ,
2730-486: Is referred to as the primary extension or primary projection. As with wing formulae, this measurement is useful for distinguishing between similarly plumaged birds; however, unlike wing formulae, it is not necessary to have the bird in-hand to make the measurement. Rather, this is a useful relative measurement—some species have long primary extensions, while others have shorter ones. Among the Empidonax flycatchers of
2821-410: Is theorized that the differences help young birds compensate for their inexperience, weaker flight muscles and poorer flying ability. A wing formula describes the shape of distal end of a bird's wing in a mathematical way. It can be used to help distinguish between species with similar plumages, and thus is particularly useful for those who ring (band) birds. To determine a bird's wing formula,
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2912-436: Is to determine their independence and reliability. In contexts such as historical writing, it is almost always advisable to use primary sources and that "if none are available, it is only with great caution that [the author] may proceed to make use of secondary sources." Sreedharan believes that primary sources have the most direct connection to the past and that they "speak for themselves" in ways that cannot be captured through
3003-646: The World Digital Library and Flickr Commons have items from all over the world. Trove has primary sources from Australia. Most primary source materials are not digitized and may only be represented online with a record or finding aid . Both digitized and not digitized materials can be found through catalogs such as WorldCat , the Library of Congress catalog , the National Archives catalog , and so on. History as an academic discipline
3094-433: The olecranon and performing the same function as true tertials) in an effort to distinguish them from other secondaries. The term humeral is sometimes used for birds such as the albatrosses and pelicans that have a long humerus. The calami of the flight feathers are protected by a layer of non-flight feathers called covert feathers or tectrices (singular tectrix ), at least one layer of them both above and beneath
3185-716: The Latin word for "helmsman", help the bird to brake and steer in flight. These feathers lie in a single horizontal row on the rear margin of the anatomic tail. Only the central pair are attached (via ligaments ) to the tail bones; the remaining rectrices are embedded into the rectricial bulbs , complex structures of fat and muscle that surround those bones. Rectrices are always paired, with a vast majority of species having six pairs. They are absent in grebes and some ratites , and greatly reduced in size in penguins. Many grouse species have more than 12 rectrices. In some species (including ruffed grouse , hazel grouse and common snipe ),
3276-418: The airfoil shape of the bird's wing. Secondaries tend to be shorter and broader than primaries, with blunter ends (see illustration). They vary in number from 6 in hummingbirds to as many as 40 in some species of albatross . In general, larger and longer-winged species have a larger number of secondaries. Birds in more than 40 non-passerine families seem to be missing the fifth secondary feather on each wing,
3367-418: The album Telephono Other uses in arts, entertainment, and media [ edit ] Primaries or primary beams, in E. E. Smith's science-fiction series Lensman Primary (film) , American political documentary (1960) Computing [ edit ] PRIMARY, an X Window selection Primary data storage , computer technology used to retain digital data Primary server , main server on
3458-469: The available documents relate to England and Wales. Some digital copies of primary sources are available from the National Archives of Scotland . Many County Record Offices collections are included in Access to Archives, while others have their own online catalogs. Many County Record Offices will supply digital copies of documents. In other regions, Europeana has digitized materials from across Europe while
3549-682: The bird dives, wind flows through the modified feathers and creates a series of rising and falling notes, which is known as "winnowing". Differences between the sounds produced by these two former conspecific subspecies—and the fact that the outer two pairs of rectrices in Wilson's snipe are modified, while only the single outermost pair are modified in common snipe—were among the characteristics used to justify their splitting into two distinct and separate species. Flight feathers are also used by some species in visual displays. Male standard-winged and pennant-winged nightjars have modified P2 primaries (using
3640-405: The bird is in flight, especially in the case of raptors. The trailing edge of the wing of a juvenile bird can appear almost serrated, due to the feathers' sharp tips, while that of an older bird will be straighter-edged. The flight feathers of a juvenile bird will also be uniform in length, since they all grew at the same time. Those of adults will be of various lengths and levels of wear, since each
3731-444: The bird's "thumb" and normally lie flush against the anterior edge of the wing—function in the same way as the slats on an airplane wing, allowing the wing to achieve a higher than normal angle of attack – and thus lift – without resulting in a stall . By manipulating its thumb to create a gap between the alula and the rest of the wing, a bird can avoid stalling when flying at low speeds or landing. The development of
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3822-404: The bird's newly strengthened tail is best able to cope with the loss of the crucial central rectrices. Ground-feeding woodpeckers, such as the wrynecks , do not have this modified moult strategy; in fact, wrynecks moult their outer tail feathers first, with moult proceeding proximally from there. There are often substantial differences between the remiges and rectrices of adults and juveniles of
3913-454: The bird's wing closed, so as to maintain the relative positions of the feathers. While there can be considerable variation across members of a species—and while the results are obviously impacted by the effects of moult and feather regeneration—even very closely related species show clear differences in their wing formulas. The distance that a bird's longest primaries extend beyond its longest secondaries (or tertials) when its wings are folded
4004-451: The brachial region and are not considered true remiges as they are not supported by attachment to the corresponding bone, in this case the humerus. These elongated "true" tertials act as a protective cover for all or part of the folded primaries and secondaries, and do not qualify as flight feathers as such. However, many authorities use the term tertials to refer to the shorter, more symmetrical innermost secondaries of passerines (arising from
4095-609: The carpal joint) was formerly thought to be absent in some species, but the modern view of this diastataxy is that there is a gap between the fourth and fifth secondaries. Tertiary feathers growing upon the adjoining portion of the brachium are not considered true remiges. The moult of their flight feathers can cause serious problems for birds, as it can impair their ability to fly. Different species have evolved different strategies for coping with this, ranging from dropping all their flight feathers at once (and thus becoming flightless for some relatively short period of time) to extending
4186-463: The centermost pair outwards in both directions. The flight feathers of some species provide additional functionality. In some species, for example, either remiges or rectrices make a sound during flight. These sounds are most often associated with courtship or territorial displays. The outer primaries of male broad-tailed hummingbirds produce a distinctive high-pitched trill, both in direct flight and in power-dives during courtship displays; this trill
4277-426: The context in which it is used. Although many primary sources remain in private hands, others are located in archives , libraries , museums , historical societies , and special collections . These can be public or private. Some are affiliated with universities and colleges, while others are government entities. Materials relating to one area might be located in many different institutions. These can be distant from
4368-456: The descendant numbering scheme explained above) which are displayed during their courtship rituals. In the standard-winged nightjar, this modified primary consists of an extremely long shaft with a small "pennant" (actually a large web of barbules) at the tip. In the pennant-winged nightjar, the P2 primary is an extremely long (but otherwise normal) feather, while P3, P4 and P5 are successively shorter;
4459-570: The digitized primary source collections of many libraries, archives, and museums. The Internet Archive also has primary source materials in many formats. In the UK, the National Archives provides a consolidated search of its own catalog and a wide variety of other archives listed on the Access to Archives index. Digital copies of various classes of documents at the National Archives (including wills) are available from DocumentsOnline. Most of
4550-453: The distance between the tip of the most distal primary and the tip of its greater covert (the longest of the feathers that cover and protect the shaft of that primary) is measured in millimeters. In some cases, this results in a positive number (e.g., the primary extends beyond its greater covert), while in other cases it is a negative number (e.g. the primary is completely covered by the greater covert, as happens in some passerine species). Next,
4641-504: The dramatically coiled twin plumes of the magnificent bird-of-paradise . Owls have remiges which are serrated rather than smooth on the leading edge. This adaptation disrupts the flow of air over the wings, eliminating the noise that airflow over a smooth surface normally creates, and allowing the birds to fly and hunt silently. The rectrices of woodpeckers are proportionately short and very stiff, allowing them to better brace themselves against tree trunks while feeding. This adaptation
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#17327661073094732-412: The ends. These plumes are raised up over the bird's head (along with a fine spray of modified uppertail coverts) during his extraordinary display. Rectrix modification reaches its pinnacle among the birds of paradise , which display an assortment of often bizarrely modified feathers, ranging from the extremely long plumes of the ribbon-tailed astrapia (nearly three times the length of the bird itself) to
4823-443: The event that a species is missing the small distal 10th primary, as some passerines are, its lack does not impact the numbering of the remaining primaries. Ascendant numbering, on the other hand, allows for uniformity in the numbering of non-passerine primaries, as they almost invariably have four attached to the manus regardless of how many primaries they have overall. This method is particularly useful for indicating wing formulae, as
4914-413: The feather edges. These narrowings are called either notches or emarginations depending on the degree of their slope. An emargination is a gradual change, and can be found on either side of the feather. A notch is an abrupt change, and is only found on the wider trailing edge of the remex. (Both are visible on the primary in the photo showing the feathers; they can be found about halfway along both sides of
5005-469: The filter of secondary sources. In scholarly writing, the objective of classifying sources is to determine the independence and reliability of sources. Though the terms primary source and secondary source originated in historiography as a way to trace the history of historical ideas, they have been applied to many other fields. For example, these ideas may be used to trace the history of scientific theories, literary elements, and other information that
5096-437: The flight feathers is to aid in the generation of both thrust and lift , thereby enabling flight . The flight feathers of some birds perform additional functions, generally associated with territorial displays, courtship rituals or feeding methods. In some species, these feathers have developed into long showy plumes used in visual courtship displays, while in others they create a sound during display flights. Tiny serrations on
5187-415: The flight feathers of other birds. In addition, the emu 's remiges are proportionately much reduced in size, while those of the cassowaries are reduced both in number and structure, consisting merely of 5–6 bare quills. Most ratites have completely lost their rectrices; only the ostrich still has them. Penguins have lost their differentiated flight feathers. As adults, their wings and tail are covered with
5278-407: The flight feathers of the wings as well as above and below the rectrices of the tail. These feathers may vary widely in size – in fact, the upper tail tectrices of the male peafowl , rather than its rectrices, are what constitute its elaborate and colorful "train". The outermost primaries of large soaring birds, particularly raptors, often show a pronounced narrowing at some variable distance along
5369-418: The fully formed feather. These growth bars and their widths have been used to determine the daily nutritional status of birds. Each light and dark bar correspond to around 24 hours and the use of this technique has been called ptilochronology (analogous to dendrochronology ). In general, juveniles have feathers which are narrower and more sharply pointed at the tip. This can be particularly visible when
5460-407: The leading edge of their remiges help owls to fly silently (and therefore hunt more successfully), while the extra-stiff rectrices of woodpeckers help them to brace against tree trunks as they hammer on them. Even flightless birds still retain flight feathers, though sometimes in radically modified forms. The remiges are divided into primary and secondary feathers based on their position along
5551-541: The left hand feather—a shallow notch on the left, and a gradual emargination on the right.) The presence of notches and emarginations creates gaps at the wingtip; air is forced through these gaps, increasing the generation of lift. Feathers on the alula or bastard wing are not generally considered to be flight feathers in the strict sense; though they are asymmetrical, they lack the length and stiffness of most true flight feathers. However, alula feathers are definitely an aid to slow flight. These feathers—which are attached to
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#17327661073095642-414: The letter S, those of tertials with T and those of rectrices with R. Most authorities number the primaries descendantly, starting from the innermost primary (the one closest to the secondaries) and working outwards; others number them ascendantly, from the most distal primary inwards. There are some advantages to each method. Descendant numbering follows the normal sequence of most birds' primary moult. In
5733-465: The long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges ( / ˈ r ɛ m ɪ dʒ iː z / ), singular remex ( / ˈ r iː m ɛ k s / ), while those on the tail are called rectrices ( / ˈ r ɛ k t r ɪ s iː z / or / r ɛ k ˈ t r aɪ s iː z / ), singular rectrix ( / ˈ r ɛ k t r ɪ k s / ). The primary function of
5824-404: The longest primary feather is identified, and the differences between the length of that primary and that of all remaining primaries and of the longest secondary are also measured, again in millimeters. If any primary shows a notch or emargination, this is noted, and the distance between the feather's tip and any notch is measured, as is the depth of the notch. All distance measurements are made with
5915-528: The loss of even a few flight feathers. A protracted moult like the one described above would leave them vulnerable to predators for a sizeable portion of the year. Instead, these birds lose all their flight feathers at once. This leaves them completely flightless for a period of three to four weeks, but means their overall period of vulnerability is significantly shorter than it would otherwise be. Eleven families of birds, including loons , grebes and most waterfowl , have this moult strategy. The cuckoos show what
6006-501: The main primary sources are books, essays, and letters written by intellectuals; these intellectuals may include historians, whose books and essays are therefore considered primary sources for the intellectual historian, though they are secondary sources in their own topical fields. In religious history , the primary sources are religious texts and descriptions of religious ceremonies and rituals . A study of cultural history could include fictional sources such as novels or plays. In
6097-422: The moult over a period of several years. Remiges (from the Latin for "oarsman") are located on the posterior side of the wing. Ligaments attach the long calami (quills) firmly to the wing bones, and a thick, strong band of tendinous tissue known as the postpatagium helps to hold and support the remiges in place. Corresponding remiges on individual birds are symmetrical between the two wings, matching to
6188-570: The next feathers in line (P2 and S2 on the wing, and both R2s on the tail) are dropped. This pattern of drop and replacement continues until moult reaches either end of the wing or tail. The speed of the moult can vary somewhat within a species. Some passerines that breed in the Arctic , for example, drop many more flight feathers at once (sometimes becoming briefly flightless) in order to complete their entire wing moult prior to migrating south, while those same species breeding at lower latitudes undergo
6279-450: The number of primaries they possess. The number in non-passerines generally varies between 9 and 11, but grebes , storks and flamingos have 12, and ostriches have 16. While most modern passerines have ten primaries, some have only nine. Those with nine are missing the most distal primary (sometimes called the remicle) which is typically very small and sometimes rudimentary in passerines. The outermost primaries—those connected to
6370-452: The number varies among individuals. Domestic pigeons have a highly variable number as a result of changes brought about over centuries of selective breeding. In order to make the discussion of such topics as moult processes or body structure easier, ornithologists assign a number to each flight feather. By convention, the numbers assigned to primary feathers always start with the letter P (P1, P2, P3, etc.) , those of secondaries with
6461-492: The oldest period in the Geologic time scale (obsolete) Primary, a stage in a thermonuclear explosive Primary circuit , electrical circuit in a transformer that receives current, as opposed to secondary circuit Primary field , type of field in conformal field theory Primary mirror , principal light-gathering surface of a reflecting telescope Primary power line , electric power transmission line fed to or from
6552-434: The only eyewitness reports of an event may be memoirs , autobiographies, or oral interviews that were taken years later. Sometimes the only evidence relating to an event or person in the distant past was written or copied decades or centuries later. Manuscripts that are sources for classical texts can be copies of documents or fragments of copies of documents. This is a common problem in classical studies , where sometimes only
6643-419: The opinion of the reviewer about the book rather than a summary of the book, becomes a primary source. If a historical text discusses old documents to derive a new historical conclusion, it is considered to be a primary source for the new conclusion. Examples in which a source can be both primary and secondary include an obituary or a survey of several volumes of a journal counting the frequency of articles on
6734-839: The original source of the document. For example, the Huntington Library in California houses many documents from the United Kingdom. In the US, digital copies of primary sources can be retrieved from a number of places. The Library of Congress maintains several digital collections where they can be retrieved. Some examples are American Memory and Chronicling America . The National Archives and Records Administration also has digital collections in Digital Vaults . The Digital Public Library of America searches across
6825-418: The outermost primary is the one with which the measurements begin. Secondaries are always numbered ascendantly, starting with the outermost secondary (the one closest to the primaries) and working inwards. Tertials are also numbered ascendantly, but in this case, the numbers continue on consecutively from that given to the last secondary (e.g. ... S5, S6, T7, T8, ... etc.). Rectrices are always numbered from
6916-418: The overall effect is a broadly forked wingtip with a very long plume beyond the lower half of the fork. Males of many species, ranging from the widely introduced ring-necked pheasant to Africa's many whydahs , have one or more elongated pairs of rectrices, which play an often-critical role in their courtship rituals. The outermost pair of rectrices in male lyrebirds are extremely long and strongly curved at
7007-423: The phalanges—are sometimes known as pinions . Secondaries are connected to the ulna . In some species, the ligaments that bind these remiges to the bone connect to small, rounded projections, known as quill knobs , on the ulna; in other species, no such knobs exist. Secondary feathers remain close together in flight (they cannot be individually separated like the primaries can) and help to provide lift by creating
7098-426: The principal source of thrust , moving the bird forward through the air. The mechanical properties of primaries are important in supporting flight. Most thrust is generated on the downstroke of flapping flight. However, on the upstroke (when the bird often draws its wing in close to its body), the primaries are separated and rotated, reducing air resistance while still helping to provide some thrust. The flexibility of
7189-498: The purpose of finding useful primary sources. A work on history is not likely to be taken seriously as a scholarship if it only cites secondary sources, as it does not indicate that original research has been done. However, primary sources – particularly those from before the 20th century – may have hidden challenges. "Primary sources, in fact, are usually fragmentary, ambiguous, and very difficult to analyze and interpret." Obsolete meanings of familiar words and social context are among
7280-559: The reason for identifying a text as the "primary source" may devolve from the fact that no copy of the original source material exists, or that it is the oldest extant source for the information cited. Historians must occasionally contend with forged documents that purport to be primary sources. These forgeries have usually been constructed with a fraudulent purpose, such as promulgating legal rights, supporting false pedigrees, or promoting particular interpretations of historic events. The investigation of documents to determine their authenticity
7371-585: The remiges (and alulae) of nestling hoatzins is much delayed compared to the development of these feathers in other young birds, presumably because young hoatzins are equipped with claws on their first two digits . They use these small rounded hooks to grasp branches when clambering about in trees, and feathering on these digits would presumably interfere with that functionality. Most youngsters shed their claws sometime between their 70th and 100th day of life, but some retain them— though callused -over and unusable— into adulthood. Rectrices (singular rectrix) from
7462-410: The remiges on the wingtips of large soaring birds also allows for the spreading of those feathers, which helps to reduce the creation of wingtip vortices , thereby reducing drag . The barbules on these feathers, friction barbules, are specialized with large lobular barbicels that help grip and prevent slippage of overlying feathers and are present in most of the flying birds. Species vary somewhat in
7553-524: The same small, stiff, slightly curved feathers as are found on the rest of their bodies. The ground-dwelling kākāpō , which is the world's only flightless parrot, has remiges which are shorter, rounder and more symmetrically vaned than those of parrots capable of flight; these flight feathers also contain fewer interlocking barbules near their tips. Once they have finished growing, feathers are essentially dead structures. Over time, they become worn and abraded, and need to be replaced. This replacement process
7644-415: The same species. Because all juvenile feathers are grown at once—a tremendous energy burden to the developing bird—they are softer and of poorer quality than the equivalent feathers of adults, which are moulted over a longer period of time (as long as several years in some cases). As a result, they wear more quickly. As feathers grow at variable rates, these variations lead to visible dark and light bands in
7735-492: The second pair of rectrices (both R2 feathers) are the first to drop. (In some species in the genera Celeus and Dendropicos , the third pair is the first dropped.) The pattern of feather drop and replacement proceeds as described for passerines (above) until all other rectrices have been replaced; only then are the central tail rectrices moulted. This provides some protection to the growing feathers, since they're always covered by at least one existing feather, and also ensures that
7826-459: The server farm Education [ edit ] Primary education , the first stage of compulsory education Primary FRCA , academic examination for anaesthetists in the U.K. Primary school , school providing primary education Mathematics [ edit ] p -group of prime power order Primary decomposition into primary ideals Primary ideals , concept in commutative algebra Primary number , positive integer power of
7917-492: The study of history as an academic discipline, a primary source (also called an original source ) is an artifact , document , diary , manuscript , autobiography , recording, or any other source of information that was created at the time under study. It serves as an original source of information about the topic. Similar definitions can be used in library science and other areas of scholarship, although different fields have somewhat different definitions. In journalism ,
8008-450: The title Primary . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Primary&oldid=1253237303 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Primary source In
8099-416: The traps that await the newcomer to historical studies. For this reason, the interpretation of primary texts is typically taught as part of an advanced college or postgraduate history course, although advanced self-study or informal training is also possible. In many fields and contexts, such as historical writing, it is almost always advisable to use primary sources if possible, and "if none are available, it
8190-466: The wing or tail and proceeds in a sequential manner in one or both directions from there. For example, most passerines have a focus between the innermost primary (P1, using the numbering scheme explained above) and outermost secondary (S1), and a focus point in the middle of the center pair of rectrices. As passerine moult begins, the two feathers closest to the focus are the first to drop. When replacement feathers reach roughly half of their eventual length,
8281-418: The wing. There are typically 11 primaries attached to the manus (six attached to the metacarpus and five to the phalanges), but the outermost primary, called the remicle, is often rudimentary or absent; certain birds, notably the flamingos, grebes, and storks, have seven primaries attached to the metacarpus and 12 in all. Secondary feathers are attached to the ulna. The fifth secondary remex (numbered inwards from
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