From about 1800 a fresh influx of Greek architectural examples, seen through the medium of etchings and engravings, gave a new impetus to neoclassicism, the Greek Revival. There was little to no direct knowledge of Greek civilization before the middle of the 18th century in Western Europe, when an expedition funded by the Society of Dilettanti in 1751 and led by James Stuart and Nicholas Revett began serious archaeological enquiry. Stuart was commissioned after his return from Greece by George Lyttelton to produce the first Greek building in England, the garden temple at Hagley Hall (1758–59). A number of British architects in the second half of the century took up the expressive challenge of the Doric from their aristocratic patrons, including Joseph Bonomi and John Soane, but it was to remain the private enthusiasm of connoisseurs up to the first decade of the 19th century.


Seen in its wider social context, Greek Revival architecture sounded a new note of sobriety and restraint in public buildings in Britain around 1800 as an assertion of nationalism attendant on the Act of Union, the Napoleonic Wars, and the clamour for political reform. It was to be William Wilkins's winning design for the public competition for Downing College, Cambridge that announced the Greek style was to be the dominant idiom in architecture. Wilkins and Robert Smirke went on to build some of the most important buildings of the era, including the Theatre Royal, Covent Garden (1808–09), the General Post Office (1824–29) and the British Museum (1823–48), Wilkins University College London (1826–30) and the National Gallery (1832–38). In Scotland, Thomas Hamilton (1784–1858), in collaboration with the artists Andrew Wilson (1780–1848) and Hugh William Williams (1773–1829) created monuments and buildings of international significance; the Burns Monument at Alloway (1818) and the (Royal) High School in Edinburgh (1823–29).


At the same time the Empire style in France was a more grandiose wave of neoclassicism in architecture and the decorative arts. Mainly based on Imperial Roman styles, it originated in, and took its name from, the rule of Napoleon I in the First French Empire, where it was intended to idealize Napoleon's leadership and the French state. The style corresponds to the more bourgeois Biedermeier style in the German-speaking lands, Federal style in the United States, the Regency style in Britain, and the Napoleonstil in Sweden. According to the art historian Hugh Honour "so far from being, as is sometimes supposed, the culmination of the Neo-classical movement, the Empire marks its rapid decline and transformation back once more into a mere antique revival, drained of all the high-minded ideas and force of conviction that had inspired its masterpieces".


High neoclassicism was an international movement. Though neoclassical architecture employed the same classical vocabulary as Late Baroque architecture, it tended to emphasize its planar qualities, rather than sculptural volumes. Projections and recessions and their effects of light and shade were more flat; sculptural bas-reliefs were flatter and tended to be enframed in friezes, tablets or panels. Its clearly articulated individual features were isolated rather than interpenetrating, autonomous and complete in themselves.


Neoclassicism also influenced city planning; the ancient Romans had used a consolidated scheme for city planning for both defence and civil convenience, however, the roots of this scheme go back to even older civilizations. At its most basic, the grid system of streets, a central forum with city services, two main slightly wider boulevards, and the occasional diagonal street were characteristic of the very logical and orderly Roman design. Ancient façades and building layouts were oriented to these city design patterns and they tended to work in proportion with the importance of public buildings.


From the middle of the 18th century, exploration and publication changed the course of British architecture towards a purer vision of the Ancient Greco-Roman ideal. James 'Athenian' Stuart's work The Antiquities of Athens and Other Monuments of Greece was very influential in this regard, as were Robert Wood's Palmyra and Baalbec. A combination of simple forms and high levels of enrichment was adopted by the majority of contemporary British architects and designers. The revolution begun by Stuart was soon to be eclipsed by the work of the Adam Brothers, James Wyatt, Sir William Chambers, George Dance, James Gandon and provincially based architects such as John Carr and Thomas Harrison of Chester.


In the early 20th century, the writings of Albert Richardson were responsible for a re-awakening of interest in pure neoclassical design. Vincent Harris (compare Harris's colonnaded and domed interior of Manchester Central Reference Library to the colonnaded and domed interior by John Carr and R R Duke), Bradshaw Gass & Hope and Percy Thomas were among those who designed public buildings in the neoclassical style in the interwar period. In the British Raj in India, Sir Edwin Lutyens' monumental city planning for New Delhi marked the sunset of neoclassicism. In Scotland and the north of England, where the Gothic Revival was less strong, architects continued to develop the neoclassical style of William Henry Playfair. The works of Cuthbert Brodrick and Alexander Thomson show that by the end of the 19th century the results could be powerful and eccentric.


The first phase of neoclassicism in France is expressed in the "Louis XVI style" of architects like Ange-Jacques Gabriel (Petit Trianon, 1762–68); the second phase, in the styles called Directoire and "Empire", might be characterized by Jean Chalgrin's severe astylar Arc de Triomphe (designed in 1806). In England the two phases might be characterized first by the structures of Robert Adam, the second by those of Sir John Soane. The interior style in France was initially a Parisian style, the "Goût grec" ("Greek style") not a court style. Only when the young king acceded to the throne in 1771 did Marie Antoinette, his fashion-loving Queen, bring the "Louis XVI" style to court.


What little there was, started with Charles de Wailly's crypt in the church of St Leu-St Gilles (1773–80), and Claude Nicolas Ledoux's Barriere des Bonshommes (1785–89). First-hand evidence of Greek architecture was of very little importance to the French, due to the influence of Marc-Antoine Laugier's doctrines that sought to discern the principles of the Greeks instead of their mere practices. It would take until Laboustre's Neo-Grec of the second Empire for the Greek revival to flower briefly in France.


The earliest examples of neoclassical architecture in Hungary may be found in Vác. In this town the triumphal arch and the neoclassical façade of the baroque Cathedral were designed by the French architect Isidor Marcellus Amandus Ganneval (Isidore Canevale) in the 1760s. Also the work of a French architect Charles Moreau is the garden façade of the Esterházy Palace (1797–1805) in Kismarton (today Eisenstadt in Austria). The two principal architect of Neoclassicism in Hungary was Mihály Pollack and József Hild. Pollack's major work is the Hungarian National Museum (1837–1844). Hild is famous for his designs for the Cathedral of Eger and Esztergom.


Neoclassical architecture was introduced in Malta in the late 18th century, during the final years of Hospitaller rule. Early examples include the Bibliotheca (1786), the De Rohan Arch (1798) and the Hompesch Gate (1801). However, neoclassical architecture only became popular in Malta following the establishment of British rule in the early 19th century. In 1814, a neoclassical portico decorated with the British coat of arms was added to the Main Guard building so as to serve as a symbol of British Malta. Other 19th century neoclassical buildings include RNH Bighi (1832), St Paul's Pro-Cathedral (1844), the Rotunda of Mosta (1860) and the now destroyed Royal Opera House (1866).


As of the first decade of the 21st century, contemporary neoclassical architecture is usually classed under the umbrella term of New Classical Architecture. Sometimes it is also referred to as Neo-Historicism/Revivalism, Traditionalism or simply neoclassical architecture like the historical style. For sincere traditional-style architecture that sticks to regional architecture, materials and craftsmanship, the term Traditional Architecture (or vernacular) is mostly used. The Driehaus Architecture Prize is awarded to major contributors in the field of 21st century traditional or classical architecture, and comes with a prize money twice as high as that of the modernist Pritzker Prize.


After a lull during the period of modern architectural dominance (roughly post-World War II until the mid-1980s), neoclassicism has seen somewhat of a resurgence. This rebirth can be traced to the movement of New Urbanism and postmodern architecture's embrace of classical elements as ironic, especially in light of the dominance of Modernism. While some continued to work with classicism as ironic, some architects such as Thomas Gordon Smith, began to consider classicism seriously. While some schools had interest in classical architecture, such as the University of Virginia, no school was purely dedicated to classical architecture. In the early 1990s a program in classical architecture was started by Smith and Duncan Stroik at the University of Notre Dame that continues successfully. Programs at the University of Miami, Andrews University, Judson University and The Prince's Foundation for Building Community have trained a number of new classical architects since this resurgence. Today one can find numerous buildings embracing neoclassical style, since a generation of architects trained in this discipline shapes urban planning.


In Britain a number of architects are active in the neoclassical style. Two new university Libraries, Quinlan Terry's Maitland Robinson Library at Downing College and ADAM Architecture's Sackler Library illustrate that the approach taken can range from the traditional, in the former case, to the unconventional, in the latter case. Recently, Prince Charles came under controversy for promoting a classically designed development on the land of the former Chelsea Barracks in London. Writing to the Qatari Royal family (who were funding the development through the property development company Qatari Diar) he condemned the accepted modernist plans, instead advocating a classical approach. His appeal was met with success and the plans were withdrawn. A new design by architecture house Dixon Jones is currently being drafted.


South Slavic dialects historically formed a continuum. The turbulent history of the area, particularly due to expansion of the Ottoman Empire, resulted in a patchwork of dialectal and religious differences. Due to population migrations, Shtokavian became the most widespread in the western Balkans, intruding westwards into the area previously occupied by Chakavian and Kajkavian (which further blend into Slovenian in the northwest). Bosniaks, Croats and Serbs differ in religion and were historically often part of different cultural circles, although a large part of the nations have lived side by side under foreign overlords. During that period, the language was referred to under a variety of names, such as "Slavic", "Illyrian", or according to region, "Bosnian", "Serbian" and "Croatian", the latter often in combination with "Slavonian" or "Dalmatian".


Serbo-Croatian was standardized in the mid-19th-century Vienna Literary Agreement by Croatian and Serbian writers and philologists, decades before a Yugoslav state was established. From the very beginning, there were slightly different literary Serbian and Croatian standards, although both were based on the same Shtokavian subdialect, Eastern Herzegovinian. In the 20th century, Serbo-Croatian served as the official language of the Kingdom of Yugoslavia (when it was called "Serbo-Croato-Slovenian"), and later as one of the official languages of the Socialist Federal Republic of Yugoslavia. The breakup of Yugoslavia affected language attitudes, so that social conceptions of the language separated on ethnic and political lines. Since the breakup of Yugoslavia, Bosnian has likewise been established as an official standard in Bosnia and Herzegovina, and there is an ongoing movement to codify a separate Montenegrin standard. Serbo-Croatian thus generally goes by the ethnic names Serbian, Croatian, Bosnian, and sometimes Montenegrin and Bunjevac.


Like other South Slavic languages, Serbo-Croatian has a simple phonology, with the common five-vowel system and twenty-five consonants. Its grammar evolved from Common Slavic, with complex inflection, preserving seven grammatical cases in nouns, pronouns, and adjectives. Verbs exhibit imperfective or perfective aspect, with a moderately complex tense system. Serbo-Croatian is a pro-drop language with flexible word order, subject–verb–object being the default. It can be written in Serbian Cyrillic or Gaj's Latin alphabet, whose thirty letters mutually map one-to-one, and the orthography is highly phonemic in all standards.


Throughout the history of the South Slavs, the vernacular, literary, and written languages (e.g. Chakavian, Kajkavian, Shtokavian) of the various regions and ethnicities developed and diverged independently. Prior to the 19th century, they were collectively called "Illyric", "Slavic", "Slavonian", "Bosnian", "Dalmatian", "Serbian" or "Croatian". As such, the term Serbo-Croatian was first used by Jacob Grimm in 1824, popularized by the Vienna philologist Jernej Kopitar in the following decades, and accepted by Croatian Zagreb grammarians in 1854 and 1859. At that time, Serb and Croat lands were still part of the Ottoman and Austrian Empires. Officially, the language was called variously Serbo-Croat, Croato-Serbian, Serbian and Croatian, Croatian and Serbian, Serbian or Croatian, Croatian or Serbian. Unofficially, Serbs and Croats typically called the language "Serbian" or "Croatian", respectively, without implying a distinction between the two, and again in independent Bosnia and Herzegovina, "Bosnian", "Croatian", and "Serbian" were considered to be three names of a single official language. Croatian linguist Dalibor Brozović advocated the term Serbo-Croatian as late as 1988, claiming that in an analogy with Indo-European, Serbo-Croatian does not only name the two components of the same language, but simply charts the limits of the region in which it is spoken and includes everything between the limits (‘Bosnian’ and ‘Montenegrin’). Today, use of the term "Serbo-Croatian" is controversial due to the prejudice that nation and language must match. It is still used for lack of a succinct alternative, though alternative names have been used, such as Bosnian/Croatian/Serbian (BCS), which is often seen in political contexts such as the Hague War Crimes tribunal.


In the mid-19th century, Serbian (led by self-taught writer and folklorist Vuk Stefanović Karadžić) and most Croatian writers and linguists (represented by the Illyrian movement and led by Ljudevit Gaj and Đuro Daničić), proposed the use of the most widespread dialect, Shtokavian, as the base for their common standard language. Karadžić standardised the Serbian Cyrillic alphabet, and Gaj and Daničić standardized the Croatian Latin alphabet, on the basis of vernacular speech phonemes and the principle of phonological spelling. In 1850 Serbian and Croatian writers and linguists signed the Vienna Literary Agreement, declaring their intention to create a unified standard. Thus a complex bi-variant language appeared, which the Serbs officially called "Serbo-Croatian" or "Serbian or Croatian" and the Croats "Croato-Serbian", or "Croatian or Serbian". Yet, in practice, the variants of the conceived common literary language served as different literary variants, chiefly differing in lexical inventory and stylistic devices. The common phrase describing this situation was that Serbo-Croatian or "Croatian or Serbian" was a single language. During the Austro-Hungarian occupation of Bosnia and Herzegovina, the language of all three nations was called "Bosnian" until the death of administrator von Kállay in 1907, at which point the name was changed to "Serbo-Croatian".


West European scientists judge the Yugoslav language policy as an exemplary one: although three-quarters of the population spoke one language, no single language was official on a federal level. Official languages were declared only at the level of constituent republics and provinces, and very generously: Vojvodina had five (among them Slovak and Romanian, spoken by 0.5 per cent of the population), and Kosovo four (Albanian, Turkish, Romany and Serbo-Croatian). Newspapers, radio and television studios used sixteen languages, fourteen were used as languages of tuition in schools, and nine at universities. Only the Yugoslav Army used Serbo-Croatian as the sole language of command, with all other languages represented in the army’s other activities—however, this is not different from other armies of multilingual states, or in other specific institutions, such as international air traffic control where English is used worldwide. All variants of Serbo-Croatian were used in state administration and republican and federal institutions. Both Serbian and Croatian variants were represented in respectively different grammar books, dictionaries, school textbooks and in books known as pravopis (which detail spelling rules). Serbo-Croatian was a kind of soft standardisation. However, legal equality could not dampen the prestige Serbo-Croatian had: since it was the language of three quarters of the population, it functioned as an unofficial lingua franca. And within Serbo-Croatian, the Serbian variant, with twice as many speakers as the Croatian, enjoyed greater prestige, reinforced by the fact that Slovene and Macedonian speakers preferred it to the Croatian variant because their languages are also Ekavian. This is a common situation in other pluricentric languages, e.g. the variants of German differ according to their prestige, the variants of Portuguese too. Moreover, all languages differ in terms of prestige: "the fact is that languages (in terms of prestige, learnability etc.) are not equal, and the law cannot make them equal".


Like most Slavic languages, there are mostly three genders for nouns: masculine, feminine, and neuter, a distinction which is still present even in the plural (unlike Russian and, in part, the Čakavian dialect). They also have two numbers: singular and plural. However, some consider there to be three numbers (paucal or dual, too), since (still preserved in closely related Slovene) after two (dva, dvije/dve), three (tri) and four (četiri), and all numbers ending in them (e.g. twenty-two, ninety-three, one hundred four) the genitive singular is used, and after all other numbers five (pet) and up, the genitive plural is used. (The number one [jedan] is treated as an adjective.) Adjectives are placed in front of the noun they modify and must agree in both case and number with it.


Comparative and historical linguistics offers some clues for memorising the accent position: If one compares many standard Serbo-Croatian words to e.g. cognate Russian words, the accent in the Serbo-Croatian word will be one syllable before the one in the Russian word, with the rising tone. Historically, the rising tone appeared when the place of the accent shifted to the preceding syllable (the so-called "Neoshtokavian retraction"), but the quality of this new accent was different – its melody still "gravitated" towards the original syllable. Most Shtokavian dialects (Neoshtokavian) dialects underwent this shift, but Chakavian, Kajkavian and the Old Shtokavian dialects did not.


The Croatian Latin alphabet (Gajica) followed suit shortly afterwards, when Ljudevit Gaj defined it as standard Latin with five extra letters that had diacritics, apparently borrowing much from Czech, but also from Polish, and inventing the unique digraphs "lj", "nj" and "dž". These digraphs are represented as "ļ, ń and ǵ" respectively in the "Rječnik hrvatskog ili srpskog jezika", published by the former Yugoslav Academy of Sciences and Arts in Zagreb. The latter digraphs, however, are unused in the literary standard of the language. All in all, this makes Serbo-Croatian the only Slavic language to officially use both the Latin and Cyrillic scripts, albeit the Latin version is more commonly used.


South Slavic historically formed a dialect continuum, i.e. each dialect has some similarities with the neighboring one, and differences grow with distance. However, migrations from the 16th to 18th centuries resulting from the spread of Ottoman Empire on the Balkans have caused large-scale population displacement that broke the dialect continuum into many geographical pockets. Migrations in the 20th century, primarily caused by urbanization and wars, also contributed to the reduction of dialectal differences.


The Serbo-Croatian dialects differ not only in the question word they are named after, but also heavily in phonology, accentuation and intonation, case endings and tense system (morphology) and basic vocabulary. In the past, Chakavian and Kajkavian dialects were spoken on a much larger territory, but have been replaced by Štokavian during the period of migrations caused by Ottoman Turkish conquest of the Balkans in the 15th and the 16th centuries. These migrations caused the koinéisation of the Shtokavian dialects, that used to form the West Shtokavian (more closer and transitional towards the neighbouring Chakavian and Kajkavian dialects) and East Shtokavian (transitional towards the Torlakian and the whole Bulgaro-Macedonian area) dialect bundles, and their subsequent spread at the expense of Chakavian and Kajkavian. As a result, Štokavian now covers an area larger than all the other dialects combined, and continues to make its progress in the enclaves where non-literary dialects are still being spoken.


Enisa Kafadar argues that there is only one Serbo-Croatian language with several varieties. This has made possible to include all four varieties into a new grammar book. Daniel Bunčić concludes that it is a pluricentric language, with four standard variants spoken in Serbia, Croatia, Montenegro and Bosnia and Herzegovina. The mutual intelligibility between their speakers "exceeds that between the standard variants of English, French, German, or Spanish". Other linguists have argued that the differences between the variants of Serbo-Croatian are less significant than those between the variants of English, German,, Dutch, and Hindi-Urdu.


The opinion of the majority of Croatian linguists[citation needed] is that there has never been a Serbo-Croatian language, but two different standard languages that overlapped sometime in the course of history. However, Croatian linguist Snježana Kordić has been leading an academic discussion on that issue in the Croatian journal Književna republika from 2001 to 2010. In the discussion, she shows that linguistic criteria such as mutual intelligibility, huge overlap in linguistic system, and the same dialectic basis of standard language provide evidence that Croatian, Serbian, Bosnian and Montenegrin are four national variants of the pluricentric Serbo-Croatian language. Igor Mandić states: "During the last ten years, it has been the longest, the most serious and most acrid discussion (…) in 21st-century Croatian culture". Inspired by that discussion, a monograph on language and nationalism has been published.


The topic of language for writers from Dalmatia and Dubrovnik prior to the 19th century made a distinction only between speakers of Italian or Slavic, since those were the two main groups that inhabited Dalmatian city-states at that time. Whether someone spoke Croatian or Serbian was not an important distinction then, as the two languages were not distinguished by most speakers. This has been used as an argument to state that Croatian literature Croatian per se, but also includes Serbian and other languages that are part of Serbo-Croatian, These facts undermine the Croatian language proponents' argument that modern-day Croatian is based on a language called Old Croatian.


However, most intellectuals and writers from Dalmatia who used the Štokavian dialect and practiced the Catholic faith saw themselves as part of a Croatian nation as far back as the mid-16th to 17th centuries, some 300 years before Serbo-Croatian ideology appeared. Their loyalty was first and foremost to Catholic Christendom, but when they professed an ethnic identity, they referred to themselves as "Slovin" and "Illyrian" (a sort of forerunner of Catholic baroque pan-Slavism) and Croat – these 30-odd writers over the span of c. 350 years always saw themselves as Croats first and never as part of a Serbian nation. It should also be noted that, in the pre-national era, Catholic religious orientation did not necessarily equate with Croat ethnic identity in Dalmatia. A Croatian follower of Vuk Karadžić, Ivan Broz, noted that for a Dalmatian to identify oneself as a Serb was seen as foreign as identifying oneself as Macedonian or Greek. Vatroslav Jagić pointed out in 1864:


The luxurious and ornate representative texts of Serbo-Croatian Church Slavonic belong to the later era, when they coexisted with the Serbo-Croatian vernacular literature. The most notable are the "Missal of Duke Novak" from the Lika region in northwestern Croatia (1368), "Evangel from Reims" (1395, named after the town of its final destination), Hrvoje's Missal from Bosnia and Split in Dalmatia (1404), and the first printed book in Serbo-Croatian, the Glagolitic Missale Romanum Glagolitice (1483).


In 1954, major Serbian and Croatian writers, linguists and literary critics, backed by Matica srpska and Matica hrvatska signed the Novi Sad Agreement, which in its first conclusion stated: "Serbs, Croats and Montenegrins share a single language with two equal variants that have developed around Zagreb (western) and Belgrade (eastern)". The agreement insisted on the equal status of Cyrillic and Latin scripts, and of Ekavian and Ijekavian pronunciations. It also specified that Serbo-Croatian should be the name of the language in official contexts, while in unofficial use the traditional Serbian and Croatian were to be retained. Matica hrvatska and Matica srpska were to work together on a dictionary, and a committee of Serbian and Croatian linguists was asked to prepare a pravopis. During the sixties both books were published simultaneously in Ijekavian Latin in Zagreb and Ekavian Cyrillic in Novi Sad. Yet Croatian linguists claim that it was an act of unitarianism. The evidence supporting this claim is patchy: Croatian linguist Stjepan Babić complained that the television transmission from Belgrade always used the Latin alphabet— which was true, but was not proof of unequal rights, but of frequency of use and prestige. Babić further complained that the Novi Sad Dictionary (1967) listed side by side words from both the Croatian and Serbian variants wherever they differed, which one can view as proof of careful respect for both variants, and not of unitarism. Moreover, Croatian linguists criticized those parts of the Dictionary for being unitaristic that were written by Croatian linguists. And finally, Croatian linguists ignored the fact that the material for the Pravopisni rječnik came from the Croatian Philological Society. Regardless of these facts, Croatian intellectuals brought the Declaration on the Status and Name of the Croatian Literary Language in 1967. On occasion of the publication’s 45th anniversary, the Croatian weekly journal Forum published the Declaration again in 2012, accompanied by a critical analysis.


In addition, like most Slavic languages, the Shtokavian verb also has one of two aspects: perfective or imperfective. Most verbs come in pairs, with the perfective verb being created out of the imperfective by adding a prefix or making a stem change. The imperfective aspect typically indicates that the action is unfinished, in progress, or repetitive; while the perfective aspect typically denotes that the action was completed, instantaneous, or of limited duration. Some Štokavian tenses (namely, aorist and imperfect) favor a particular aspect (but they are rarer or absent in Čakavian and Kajkavian). Actually, aspects "compensate" for the relative lack of tenses, because aspect of the verb determines whether the act is completed or in progress in the referred time.


The jat-reflex rules are not without exception. For example, when short jat is preceded by r, in most Ijekavian dialects developed into /re/ or, occasionally, /ri/. The prefix prě- ("trans-, over-") when long became pre- in eastern Ijekavian dialects but to prije- in western dialects; in Ikavian pronunciation, it also evolved into pre- or prije- due to potential ambiguity with pri- ("approach, come close to"). For verbs that had -ěti in their infinitive, the past participle ending -ěl evolved into -io in Ijekavian Neoštokavian.


On the other hand, the opinion of Jagić from 1864 is argued not to have firm grounds. When Jagić says "Croatian", he refers to a few cases referring to the Dubrovnik vernacular as ilirski (Illyrian). This was a common name for all Slavic vernaculars in Dalmatian cities among the Roman inhabitants. In the meantime, other written monuments are found that mention srpski, lingua serviana (= Serbian), and some that mention Croatian. By far the most competent Serbian scientist on the Dubrovnik language issue, Milan Rešetar, who was born in Dubrovnik himself, wrote behalf of language characteristics: "The one who thinks that Croatian and Serbian are two separate languages must confess that Dubrovnik always (linguistically) used to be Serbian."


Nationalists have conflicting views about the language(s). The nationalists among the Croats conflictingly claim either that they speak an entirely separate language from Serbs and Bosnians or that these two peoples have, due to the longer lexicographic tradition among Croats, somehow "borrowed" their standard languages from them.[citation needed] Bosniak nationalists claim that both Croats and Serbs have "appropriated" the Bosnian language, since Ljudevit Gaj and Vuk Karadžić preferred the Neoštokavian-Ijekavian dialect, widely spoken in Bosnia and Herzegovina, as the basis for language standardization, whereas the nationalists among the Serbs claim either that any divergence in the language is artificial, or claim that the Štokavian dialect is theirs and the Čakavian Croats'— in more extreme formulations Croats have "taken" or "stolen" their language from the Serbs.[citation needed]


In Serbia, the Serbian language is the official one, while both Serbian and Croatian are official in the province of Vojvodina. A large Bosniak minority is present in the southwest region of Sandžak, but the "official recognition" of Bosnian language is moot. Bosnian is an optional course in 1st and 2nd grade of the elementary school, while it is also in official use in the municipality of Novi Pazar. However, its nomenclature is controversial, as there is incentive that it is referred to as "Bosniak" (bošnjački) rather than "Bosnian" (bosanski) (see Bosnian language for details).


On October 9, 2006 at 6:00 a.m., the network switched to a 24-hour schedule, becoming one of the last major English-language broadcasters to transition to such a schedule. Most CBC-owned stations previously signed off the air during the early morning hours (typically from 1:00 a.m. to 6:00 a.m.). Instead of the infomercials aired by most private stations, or a simulcast of CBC News Network in the style of BBC One's nightly simulcast of BBC News Channel, the CBC uses the time to air repeats, including local news, primetime series, movies and other programming from the CBC library. Its French counterpart, Ici Radio-Canada Télé, still signs off every night.


Until 1998, the network carried a variety of American programs in addition to its core Canadian programming, directly competing with private Canadian broadcasters such as CTV and Global. Since then, it has restricted itself to Canadian programs, a handful of British programs, and a few American movies and off-network repeats. Since this change, the CBC has sometimes struggled to maintain ratings comparable to those it achieved before 1995, although it has seen somewhat of a ratings resurgence in recent years. In the 2007-08 season, hit series such as Little Mosque on the Prairie and The Border helped the network achieve its strongest ratings performance in over half a decade.


Under the CBC's current arrangement with Rogers Communications for National Hockey League broadcast rights, Hockey Night in Canada broadcasts on CBC-owned stations and affiliates are not technically aired over the CBC Television network, but over a separate CRTC-licensed part-time network operated by Rogers. This was required by the CRTC as Rogers exercises editorial control and sells all advertising time during the HNIC broadcasts, even though the CBC bug and promos for other CBC Television programs appear throughout HNIC.


The CBC's flagship newscast, The National, airs Sunday through Fridays at 10:00 p.m. EST and Saturdays at 6:00 p.m. EST. Until October 2006, CBC owned-and-operated stations aired a second broadcast of the program at 11:00 p.m.; this later broadcast included only the main news portion of the program, and excluded the analysis and documentary segment. This second airing was later replaced with other programming, and as of the 2012-13 television season, was replaced on CBC's major market stations by a half-hour late newscast. There is also a short news update, at most, on late Saturday evenings. During hockey season, this update is usually found during the first intermission of the second game of the doubleheader on Hockey Night in Canada.


In addition to the mentioned late local newscasts, CBC stations in most markets fill early evenings with local news programs, generally from 5:00 p.m. to 6:30 p.m., while most stations also air a single local newscast on weekend evenings (comprising a supper hour broadcast on Saturdays and a late evening newscast on Sundays). Other newscasts include parts of CBC News Now airing weekday at 6:00 a.m. and noon. Weekly newsmagazine the fifth estate is also a CBC mainstay, as are documentary series such as Doc Zone.


One of the most popular shows on CBC Television is the weekly Saturday night broadcast of NHL hockey games, Hockey Night in Canada. It has been televised by the network since 1952. During the NHL lockout and subsequent cancellation of the 2004-2005 hockey season, CBC instead aired various recent and classic movies, branded as Movie Night in Canada, on Saturday nights. Many cultural groups criticized this and suggested the CBC air games from minor hockey leagues; the CBC responded that most such broadcast rights were already held by other groups, but it did base each Movie Night broadcast from a different Canadian hockey venue. Other than hockey, CBC Sports properties include Toronto Raptors basketball, Toronto FC Soccer, and various other amateur and professional events.


It was also the exclusive carrier of Canadian Curling Association events during the 2004–2005 season. Due to disappointing results and fan outrage over many draws being carried on CBC Country Canada (now called Cottage Life Television, the association tried to cancel its multiyear deal with the CBC signed in 2004. After the CBC threatened legal action, both sides eventually came to an agreement under which early-round rights reverted to TSN. On June 15, 2006, the CCA announced that TSN would obtain exclusive rights to curling broadcasts in Canada as of the 2008-09 season, shutting the CBC out of the championship weekend for the first time in 40-plus years.


Many were surprised by these changes to the CBC schedule, which were apparently intended to attract a younger audience to the network; some suggested they might alienate the core CBC viewership. Another note of criticism was made when the network decided to move The National in some time zones to simulcast the American version of The One over the summer. This later became a moot point, as The One was taken off the air after two weeks after extremely low American and Canadian ratings, and the newscast resumed its regular schedule.


Beginning in 2005, the CBC has contributed production funds for the BBC Wales revival of Doctor Who, for which it received a special credit at the end of each episode. This arrangement continued until the end of fourth season, broadcast in 2008. The CBC similarly contributed to the first season of the spin-off series, Torchwood. More recently, the network has also begun picking up Canadian rights to some Australian series, including the drama series Janet King and Love Child, and the comedy-drama series Please Like Me.


On March 5, 2005, CBC Television launched a high definition simulcast of its Toronto (CBLT-DT) and Montreal (CBMT-DT) stations. Since that time, the network has also launched HD simulcasts in Vancouver (CBUT-DT), Ottawa (CBOT-DT), Edmonton (CBXT-DT), Calgary (CBRT-DT), Halifax (CBHT-DT), Windsor, (CBET-DT), Winnipeg (CBWT-DT) and St. John's (CBNT-DT). CBC HD is available nationally via satellite and on digital cable as well as for free over-the-air using a regular TV antenna and a digital tuner (included in most new television sets) on the following channels:


Most CBC television stations, including those in the major cities, are owned and operated by the CBC itself. CBC O&O stations operate as a mostly seamless national service with few deviations from the main network schedule, although there are some regional differences from time to time. For on-air identification, most CBC stations use the CBC brand rather than their call letters, not identifying themselves specifically until sign-on or sign-off (though some, like Toronto's CBLT, do not ID themselves at all except through PSIP). All CBC O&O stations have a standard call letter naming convention, in that the first two letters are "CB" (an ITU prefix allocated not to Canada, but to Chile) and the last letter is "T". Only the third letter varies from market to market; however, that letter is typically the same as the third letter of the CBC Radio One and CBC Radio 2 stations in the same market. An exception to this rule are the CBC North stations in Yellowknife, Whitehorse and Iqaluit, whose call signs begin with "CF" due to their historic association with the CBC's Frontier Coverage Package prior to the advent of microwave and satellite broadcasting.


Some stations that broadcast from smaller cities are private affiliates of the CBC, that is, stations which are owned by commercial broadcasters but predominantly incorporate CBC programming within their schedules. Such stations generally follow the CBC schedule, airing a minimum 40 hours per week of network programming. However, they may opt out of some CBC programming in order to air locally produced programs, syndicated series or programs purchased from other broadcasters, such as CTV Two, which do not have a broadcast outlet in the same market. In these cases, the CBC programming being displaced may be broadcast at a different time than the network, or may not be broadcast on the station at all. Most private affiliates generally opt out of CBC's afternoon schedule and Thursday night arts programming. Private affiliates carry the 10 p.m. broadcast of The National as a core part of the CBC schedule, but generally omitted the 11 p.m. repeat (which is no longer broadcast). Most private affiliates produce their own local newscasts for a duration of at least 35 minutes. Some of the private affiliates have begun adding CBC's overnight programming to their schedules since the network began broadcasting 24 hours a day.


Private CBC affiliates are not as common as they were in the past, as many such stations have been purchased either by the CBC itself or by Canwest Global or CHUM Limited, respectively becoming E! or A-Channel (later A, now CTV Two) stations. One private CBC affiliate, CHBC-TV in Kelowna, joined E! (then known as CH) on February 27, 2006. When a private CBC affiliate reaffiliates with another network, the CBC has normally added a retransmitter of its nearest O&O station to ensure that CBC service is continued. However, due to an agreement between CHBC and CFJC-TV in Kamloops, CFJC also disaffiliated from the CBC on February 27, 2006, but no retransmitters were installed in the licence area. Former private CBC affiliates CKPG-TV Prince George and CHAT-TV Medicine Hat disaffiliated on August 31, 2008 and joined E!, but the CBC announced it will not add new retransmitters to these areas. Incidentally, CFJC, CKPG and CHAT are all owned by an independent media company, Jim Pattison Group. With the closure of E! and other changes in the media landscape, several former CBC affiliates have since joined City or Global, or closed altogether.


According to filings to the Canadian Radio-television and Telecommunications Commission (CRTC) by Thunder Bay Electronics (owner of CBC's Thunder Bay affiliate CKPR-DT) and Bell Media (owner of CBC affiliates CFTK-TV in Terrace and CJDC-TV in Dawson Creek),[citation needed] the CBC informed them that it will not extend its association with any of its private affiliates beyond August 31, 2011. Incidentally, that was also the date for analogue to digital transition in Canada. Given recent practice and the CBC's decision not to convert any retransmitters to digital, even in markets with populations in the hundreds in thousands, it is not expected that the CBC will open new transmitters to replace its affiliates, and indeed may pare back its existing transmitter network. However, in March 2011, CKPR announced that it had come to a programming agreement with the CBC, in which the station will continue to provide CBC programming in Thunder Bay for a period of five years. On March 16, 2012, Astral Media announced the sale of its assets to Bell Media, owners of CTV and CTV Two, for $3.38 billion with CFTK and CJDC included in the acquisition. Whether the stations will remain CBC affiliates or become owned-and-operated stations of CTV or CTV Two following the completion of the merger is undetermined.


CBC Television stations can be received in many United States communities along the Canadian border over-the-air and have a significant audience in those areas. Such a phenomenon can also take place within Great Lakes communities such as Ashtabula, Ohio, which received programming from the CBC's London, Ontario, transmitter, based upon prevailing atmospheric conditions over Lake Erie. As of September 2010 CBC shut down its analogue transmitter and decided not to replace it with a digital transmitter. As a result, there is now a giant hole in the coverage of CBC in South-Western Ontario. Both CBC - Toronto and CBC - Windsor are both over 100 miles from London, ON and out of range for even the largest antennas[citation needed].


CBC's sports coverage has also attained high viewership in border markets, including its coverage of the NHL's Stanley Cup Playoffs, which was generally considered to be more complete and consistent than coverage by other networks such as NBC. Its coverage of the Olympic Games also found a significant audience in border regions, primarily due to the fact that CBC aired more events live than NBC's coverage, which had been criticized in recent years for tape delaying events to air in primetime, even if the event is being held in a market in the Pacific Time Zone during primetime hours on the East (where it would still be delayed for West coast primetime).


While its fellow Canadian broadcasters converted most of their transmitters to digital by the Canadian digital television transition deadline of August 31, 2011, CBC converted only about half of the analogue transmitters in mandatory areas to digital (15 of 28 markets with CBC Television stations, and 14 of 28 markets with Télévision de Radio-Canada stations). Due to financial difficulties reported by the corporation, the corporation published digital transition plans for none of its analogue retransmitters in mandatory markets to be converted to digital by the deadline. Under this plan, communities that receive analogue signals by rebroadcast transmitters in mandatory markets would lose their over-the-air signals as of the deadline. Rebroadcast transmitters account for 23 of the 48 CBC and Radio-Canada transmitters in mandatory markets. Mandatory markets losing both CBC and Radio-Canada over-the-air signals include London, Ontario (metropolitan area population 457,000) and Saskatoon, Saskatchewan (metro area population 257,000). In both of those markets, the corporation's television transmitters are the only ones that were not planned to be converted to digital by the deadline.


Because rebroadcast transmitters were not planned to be converted to digital, many markets stood to lose over-the-air coverage from CBC or Radio-Canada, or both. As a result, only seven of the markets subject to the August 31, 2011 transition deadline were planned to have both CBC and Radio-Canada in digital, and 13 other markets were planned to have either CBC or Radio-Canada in digital. In mid-August 2011, the CRTC granted the CBC an extension, until August 31, 2012, to continue operating its analogue transmitters in markets subject to the August 31, 2011 transition deadline. This CRTC decision prevented many markets subject to the transition deadline from losing signals for CBC or Radio-Canada, or both at the transition deadline. At the transition deadline, Barrie, Ontario lost both CBC and Radio-Canada signals as the CBC did not request that the CRTC allow these transmitters to continue operating.


In markets where a digital transmitter was installed, existing coverage areas were not necessarily maintained. For instance, the CBC implemented a digital transmitter covering Fredericton, New Brunswick in the place of the existing transmitter covering Saint John, New Brunswick and Fredericton, and decided to maintain analogue service to Saint John. According to CBC's application for this transmitter to the CRTC, the population served by the digital transmitter would be 113,930 people versus 303,465 served by the existing analogue transmitter. In Victoria, the replacement of the Vancouver analogue transmitters with digital ones only allowed only some northeastern parts of the metropolitan area (total population 330,000) to receive either CBC or Radio-Canada.


CBC announced on April 4, 2012, that it will shut down all of its approximately 620 analogue television transmitters on July 31, 2012 with no plans to install digital transmitters in their place, thus reducing the total number of the corporation's television transmitters across the country down to 27. According to the CBC, this would reduce the corporation's yearly costs by $10 million. No plans have been announced to use subchannels to maintain over-the-air signals for both CBC and Radio-Canada in markets where the corporation has one digital transmitter. In fact, in its CRTC application to shut down all of its analogue television transmitters, the CBC communicated its opposition to use of subchannels, citing costs, amongst other reasons.


On August 6, 2010, the CBC issued a press release stating that due to financial reasons, the CBC and Radio-Canada would only transition 27 transmitters total, one in each market where there was an originating station (i.e. a CBC or Radio-Canada television station located in that market). Further, the CBC stated in the release, that only 15 of the transmitters would be in place by August 31, 2011 due to lack of available funds, and that the remainder would not be on the air until as late as August 31, 2012. Additionally, the CBC stated in the release that it was asking the CRTC for permission to continue broadcasting in analogue until the identified transmitters for transition were up and running. At the time of the press release, only eight of the corporation's transmitters (four CBC and four Radio Canada) were broadcasting in digital.


On November 30, 2010, CBC's senior director of regulatory affairs issued a letter to the CRTC regarding CBC's plans for transitioning to digital. The letter states, "CBC/Radio-Canada will not be converting its analogue retransmitters in mandatory markets to digital after August 31, 2011."  On December 16, 2010, some months after the CRTC issued a bulletin reminding broadcasters that analog transmitters had to be shut off by the deadline in mandatory markets, the CBC revised the documents accompanying its August 6, 2010 news release to state that it had the money for and is striving to transition all 27 transmitters by August 31, 2011.


On March 23, 2011, the CRTC rejected an application by the CBC to install a digital transmitter serving Fredricton, New Brunswick in place of the analogue transmitter serving Fredericton and Saint John, New Brunswick, which would have served only 62.5% of the population served by the existing analogue transmitter. The CBC issued a press release stating "CBC/Radio-Canada intends to re-file its application with the CRTC to provide more detailed cost estimates that will allow the Commission to better understand the unfeasibility of replicating the Corporation’s current analogue coverage." The press release further added that the CBC suggests coverage could be maintained if the CRTC were to "allow CBC Television to continue providing the analogue service it offers today – much in the same way the Commission permitted recently in the case of Yellowknife, Whitehorse and Iqaluit."


On August 18, 2011, the CRTC issued a decision that allows CBC's mandatory market rebroadcasting transmitters in analogue to remain on-air until August 31, 2012. Before that deadline, CBC's licence renewal process would take place and CBC's digital transition plans would be examined as part of that process. The requirement remains for all of CBC's full-power transmitters occupying channels 52 to 69 to either relocate to channels 2 to 51 or become low-power transmitters. In some cases, CBC has opted to reduce the power of existing transmitters to low-power transmitters, which will result in signal loss for some viewers.


On July 17, 2012, the CRTC approved the shut down of CBC's analogue transmitters, noting that "while the Commission has the discretion to refuse to revoke broadcasting licences, even on application from a licensee, it cannot direct the CBC or any other broadcaster to continue to operate its stations and transmitters." On July 31, 2012, at around 11:59 p.m. in each time zone, the remaining 620 analogue transmitters were shut down, leaving the network with 27 digital television transmitters across the country, and some transmitters operated by some affiliated stations.


The Appalachian Mountains (i/ˌæpəˈleɪʃᵻn/ or /ˌæpəˈlætʃᵻn/,[note 1] French: les Appalaches), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period and once reached elevations similar to those of the Alps and the Rocky Mountains before they were eroded. The Appalachian chain is a barrier to east-west travel as it forms a series of alternating ridgelines and valleys oriented in opposition to any road running east-west.


Definitions vary on the precise boundaries of the Appalachians. The United States Geological Survey (USGS) defines the Appalachian Highlands physiographic division as consisting of thirteen provinces: the Atlantic Coast Uplands, Eastern Newfoundland Atlantic, Maritime Acadian Highlands, Maritime Plain, Notre Dame and Mégantic Mountains, Western Newfoundland Mountains, Piedmont, Blue Ridge, Valley and Ridge, Saint Lawrence Valley, Appalachian Plateaus, New England province, and the Adirondack provinces. A common variant definition does not include the Adirondack Mountains, which geologically belong to the Grenville Orogeny and have a different geological history from the rest of the Appalachians.


The range is mostly located in the United States but extends into southeastern Canada, forming a zone from 100 to 300 mi (160 to 480 km) wide, running from the island of Newfoundland 1,500 mi (2,400 km) southwestward to Central Alabama in the United States.[discuss] The range covers parts of the islands of Saint Pierre and Miquelon, which comprise an overseas territory of France. The system is divided into a series of ranges, with the individual mountains averaging around 3,000 ft (910 m). The highest of the group is Mount Mitchell in North Carolina at 6,684 feet (2,037 m), which is the highest point in the United States east of the Mississippi River.


The term Appalachian refers to several different regions associated with the mountain range. Most broadly, it refers to the entire mountain range with its surrounding hills and the dissected plateau region. The term is often used more restrictively to refer to regions in the central and southern Appalachian Mountains, usually including areas in the states of Kentucky, Tennessee, Virginia, Maryland, West Virginia, and North Carolina, as well as sometimes extending as far south as northern Alabama, Georgia and western South Carolina, and as far north as Pennsylvania, southern Ohio and parts of southern upstate New York.


While exploring inland along the northern coast of Florida in 1528, the members of the Narváez expedition, including Álvar Núñez Cabeza de Vaca, found a Native American village near present-day Tallahassee, Florida whose name they transcribed as Apalchen or Apalachen [a.paˈla.tʃɛn]. The name was soon altered by the Spanish to Apalachee and used as a name for the tribe and region spreading well inland to the north. Pánfilo de Narváez's expedition first entered Apalachee territory on June 15, 1528, and applied the name. Now spelled "Appalachian," it is the fourth-oldest surviving European place-name in the US.


In addition to the true folded mountains, known as the ridge and valley province, the area of dissected plateau to the north and west of the mountains is usually grouped with the Appalachians. This includes the Catskill Mountains of southeastern New York, the Poconos in Pennsylvania, and the Allegheny Plateau of southwestern New York, western Pennsylvania, eastern Ohio and northern West Virginia. This same plateau is known as the Cumberland Plateau in southern West Virginia, eastern Kentucky, western Virginia, eastern Tennessee, and northern Alabama.


The Appalachian belt includes, with the ranges enumerated above, the plateaus sloping southward to the Atlantic Ocean in New England, and south-eastward to the border of the coastal plain through the central and southern Atlantic states; and on the north-west, the Allegheny and Cumberland plateaus declining toward the Great Lakes and the interior plains. A remarkable feature of the belt is the longitudinal chain of broad valleys, including The Great Appalachian Valley, which in the southerly sections divides the mountain system into two unequal portions, but in the northernmost lies west of all the ranges possessing typical Appalachian features, and separates them from the Adirondack group. The mountain system has no axis of dominating altitudes, but in every portion the summits rise to rather uniform heights, and, especially in the central section, the various ridges and intermontane valleys have the same trend as the system itself. None of the summits reaches the region of perpetual snow.


Mountains of the Long Range in Newfoundland reach heights of nearly 3,000 ft (900 m). In the Chic-Choc and Notre Dame mountain ranges in Quebec, the higher summits rise to about 4,000 ft (1,200 m) elevation. Isolated peaks and small ranges in Nova Scotia and New Brunswick vary from 1,000 to 2,700 ft (300 to 800 m). In Maine several peaks exceed 4,000 ft (1,200 m), including Mount Katahdin at 5,267 feet (1,605 m). In New Hampshire, many summits rise above 5,000 ft (1,500 m), including Mount Washington in the White Mountains at 6,288 ft (1,917 m), Adams at 5,771 ft (1,759 m), Jefferson at 5,712 ft (1,741 m), Monroe at 5,380 ft (1,640 m), Madison at 5,367 ft (1,636 m), Lafayette at 5,249 feet (1,600 m), and Lincoln at 5,089 ft (1,551 m). In the Green Mountains the highest point, Mt. Mansfield, is 4,393 ft (1,339 m) in elevation; others include Killington Peak at 4,226 ft (1,288 m), Camel's Hump at 4,083 ft (1,244 m), Mt. Abraham at 4,006 ft (1,221 m), and a number of other heights exceeding 3,000 ft (900 m).


In Pennsylvania, there are over sixty summits that rise over 2,500 ft (800 m); the summits of Mount Davis and Blue Knob rise over 3,000 ft (900 m). In Maryland, Eagle Rock and Dans Mountain are conspicuous points reaching 3,162 ft (964 m) and 2,882 ft (878 m) respectively. On the same side of the Great Valley, south of the Potomac, are the Pinnacle 3,007 feet (917 m) and Pidgeon Roost 3,400 ft (1,000 m). In West Virginia, more than 150 peaks rise above 4,000 ft (1,200 m), including Spruce Knob 4,863 ft (1,482 m), the highest point in the Allegheny Mountains. A number of other points in the state rise above 4,800 ft (1,500 m). Snowshoe Mountain at Thorny Flat 4,848 ft (1,478 m) and Bald Knob 4,842 ft (1,476 m) are among the more notable peaks in West Virginia.


The Blue Ridge Mountains, rising in southern Pennsylvania and there known as South Mountain, attain elevations of about 2,000 ft (600 m) in that state. South Mountain achieves its highest point just below the Mason-Dixon line in Maryland at Quirauk Mountain 2,145 ft (654 m) and then diminishes in height southward to the Potomac River. Once in Virginia the Blue Ridge again reaches 2,000 ft (600 m) and higher. In the Virginia Blue Ridge, the following are some of the highest peaks north of the Roanoke River: Stony Man 4,031 ft (1,229 m), Hawksbill Mountain 4,066 ft (1,239 m), Apple Orchard Mountain 4,225 ft (1,288 m) and Peaks of Otter 4,001 and 3,875 ft (1,220 and 1,181 m). South of the Roanoke River, along the Blue Ridge, are Virginia's highest peaks including Whitetop Mountain 5,520 ft (1,680 m) and Mount Rogers 5,729 ft (1,746 m), the highest point in the Commonwealth.


Before the French and Indian War, the Appalachian Mountains laid on the indeterminate boundary between Britain's colonies along the Atlantic and French areas centered in the Mississippi basin. After the French and Indian War, the Proclamation of 1763 restricted settlement for Great Britain's thirteen original colonies in North America to east of the summit line of the mountains (except in the northern regions where the Great Lakes formed the boundary). Although the line was adjusted several times to take frontier settlements into account and was impossible to enforce as law, it was strongly resented by backcountry settlers throughout the Appalachians. The Proclamation Line can be seen as one of the grievances which led to the American Revolutionary War. Many frontier settlers held that the defeat of the French opened the land west of the mountains to English settlement, only to find settlement barred by the British King's proclamation. The backcountry settlers who fought in the Illinois campaign of George Rogers Clark were motivated to secure their settlement of Kentucky.


In eastern Pennsylvania the Great Appalachian Valley, or Great Valley, was accessible by reason of a broad gateway between the end of South Mountain and the Highlands, and many Germans and Moravians settled here between the Susquehanna and Delaware Rivers forming the Pennsylvania Dutch community, some of whom even now speak a unique American dialect of German known as the "Pennsylvania German language" or "Pennsylvania Dutch." These latecomers to the New World were forced to the frontier to find cheap land. With their followers of both German, English and Scots-Irish origin, they worked their way southward and soon occupied all of the Shenandoah Valley, ceded by the Iroquois, and the upper reaches of the Great Valley tributaries of the Tennessee River, ceded by the Cherokee.


Characteristic birds of the forest are wild turkey (Meleagris gallopavo silvestris), ruffed grouse (Bonasa umbellus), mourning dove (Zenaida macroura), common raven (Corvus corax), wood duck (Aix sponsa), great horned owl (Bubo virginianus), barred owl (Strix varia), screech owl (Megascops asio), red-tailed hawk (Buteo jamaicensis), red-shouldered hawk (Buteo lineatus), and northern goshawk (Accipiter gentilis), as well as a great variety of "songbirds" (Passeriformes), like the warblers in particular.


Animals that characterize the Appalachian forests include five species of tree squirrels. The most commonly seen is the low to moderate elevation eastern gray squirrel (Sciurus carolinensis). Occupying similar habitat is the slightly larger fox squirrel (Sciurus niger) and the much smaller southern flying squirrel (Glaucomys volans). More characteristic of cooler northern and high elevation habitat is the red squirrel (Tamiasciurus hudsonicus), whereas the Appalachian northern flying squirrel (Glaucomys sabrinus fuscus), which closely resembles the southern flying squirrel, is confined to northern hardwood and spruce-fir forests.


Dryer and rockier uplands and ridges are occupied by oak-chestnut type forests dominated by a variety of oaks (Quercus spp.), hickories (Carya spp.) and, in the past, by the American chestnut (Castanea dentata). The American chestnut was virtually eliminated as a canopy species by the introduced fungal chestnut blight (Cryphonectaria parasitica), but lives on as sapling-sized sprouts that originate from roots, which are not killed by the fungus. In present-day forest canopies chestnut has been largely replaced by oaks.


The oak forests of the southern and central Appalachians consist largely of black, northern red, white, chestnut and scarlet oaks (Quercus velutina, Q. rubra, Q. alba, Q. prinus and Q. coccinea) and hickories, such as the pignut (Carya glabra) in particular. The richest forests, which grade into mesic types, usually in coves and on gentle slopes, have dominantly white and northern red oaks, while the driest sites are dominated by chestnut oak, or sometimes by scarlet or northern red oaks. In the northern Appalachians the oaks, except for white and northern red, drop out, while the latter extends farthest north.


The company originated in 1911 as the Computing-Tabulating-Recording Company (CTR) through the consolidation of The Tabulating Machine Company, the International Time Recording Company, the Computing Scale Company and the Bundy Manufacturing Company. CTR was renamed "International Business Machines" in 1924, a name which Thomas J. Watson first used for a CTR Canadian subsidiary. The initialism IBM followed. Securities analysts nicknamed the company Big Blue for its size and common use of the color in products, packaging and its logo.


In 2012, Fortune ranked IBM the second largest U.S. firm in terms of number of employees (435,000 worldwide), the fourth largest in terms of market capitalization, the ninth most profitable, and the nineteenth largest firm in terms of revenue. Globally, the company was ranked the 31st largest in terms of revenue by Forbes for 2011. Other rankings for 2011/2012 include №1 company for leaders (Fortune), №1 green company in the United States (Newsweek), №2 best global brand (Interbrand), №2 most respected company (Barron's), №5 most admired company (Fortune), and №18 most innovative company (Fast Company).


IBM has 12 research laboratories worldwide, bundled into IBM Research. As of 2013[update] the company held the record for most patents generated by a business for 22 consecutive years. Its employees have garnered five Nobel Prizes, six Turing Awards, ten National Medals of Technology and five National Medals of Science. Notable company inventions or developments include the automated teller machine (ATM), the floppy disk, the hard disk drive, the magnetic stripe card, the relational database, the Universal Product Code (UPC), the financial swap, the Fortran programming language, SABRE airline reservation system, dynamic random-access memory (DRAM), copper wiring in semiconductors, the silicon-on-insulator (SOI) semiconductor manufacturing process, and Watson artificial intelligence.


IBM has constantly evolved since its inception. Over the past decade, it has steadily shifted its business mix by exiting commoditizing markets such as PCs, hard disk drives and DRAMs and focusing on higher-value, more profitable markets such as business intelligence, data analytics, business continuity, security, cloud computing, virtualization and green solutions, resulting in a higher quality revenue stream and higher profit margins. IBM's operating margin expanded from 16.8% in 2004 to 24.3% in 2013, and net profit margins expanded from 9.0% in 2004 to 16.5% in 2013.


IBM acquired Kenexa (2012) and SPSS (2009) and PwC's consulting business (2002), spinning off companies like printer manufacturer Lexmark (1991), and selling off product lines like its personal computer and x86 server businesses to Lenovo (2005, 2014). In 2014, IBM announced that it would go "fabless" by offloading IBM Micro Electronics semiconductor manufacturing to GlobalFoundries, a leader in advanced technology manufacturing, citing that semiconductor manufacturing is a capital-intensive business which is challenging to operate without scale. This transition had progressed as of early 2015[update].


On June 16, 1911, their four companies were consolidated in New York State by Charles Ranlett Flint to form the Computing-Tabulating-Recording Company (CTR). CTR's business office was in Endicott. The individual companies owned by CTR continued to operate using their established names until the businesses were integrated in 1933 and the holding company eliminated. The four companies had 1,300 employees and offices and plants in Endicott and Binghamton, New York; Dayton, Ohio; Detroit, Michigan; Washington, D.C.; and Toronto. They manufactured machinery for sale and lease, ranging from commercial scales and industrial time recorders, meat and cheese slicers, to tabulators and punched cards.


Thomas J. Watson, Sr., fired from the National Cash Register Company by John Henry Patterson, called on Flint and, in 1914, was offered CTR. Watson joined CTR as General Manager then, 11 months later, was made President when court cases relating to his time at NCR were resolved. Having learned Patterson's pioneering business practices, Watson proceeded to put the stamp of NCR onto CTR's companies. He implemented sales conventions, "generous sales incentives, a focus on customer service, an insistence on well-groomed, dark-suited salesmen and had an evangelical fervor for instilling company pride and loyalty in every worker". His favorite slogan, "THINK", became a mantra for each company's employees. During Watson's first four years, revenues more than doubled to $9 million and the company's operations expanded to Europe, South America, Asia and Australia. "Watson had never liked the clumsy hyphenated title of the CTR" and chose to replace it with the more expansive title "International Business Machines". First as a name for a 1917 Canadian subsidiary, then as a line in advertisements. For example, the McClures magazine, v53, May 1921, has a full page ad with, at the bottom:


In 1937, IBM's tabulating equipment enabled organizations to process unprecedented amounts of data, its clients including the U.S. Government, during its first effort to maintain the employment records for 26 million people pursuant to the Social Security Act, and the Third Reich, largely through the German subsidiary Dehomag. During the Second World War the company produced small arms for the American war effort (M1 Carbine, and Browning Automatic Rifle). IBM provided translation services for the Nuremberg Trials. In 1947, IBM opened its first office in Bahrain, as well as an office in Saudi Arabia to service the needs of the Arabian-American Oil Company that would grow to become Saudi Business Machines (SBM).


In 1952, Thomas Watson, Sr., stepped down after almost 40 years at the company helm; his son, Thomas Watson, Jr., was named president. In 1956, the company demonstrated the first practical example of artificial intelligence when Arthur L. Samuel of IBM's Poughkeepsie, New York, laboratory programmed an IBM 704 not merely to play checkers but "learn" from its own experience. In 1957, the FORTRAN (FORmula TRANslation) scientific programming language was developed. In 1961, Thomas J. Watson, Jr., was elected chairman of the board and Albert L. Williams became company president. The same year IBM developed the SABRE (Semi-Automatic Business-Related Environment) reservation system for American Airlines and introduced the highly successful Selectric typewriter.


In 2002, IBM acquired PwC consulting. In 2003 it initiated a project to redefine company values. Using its Jam technology, it hosted a three-day Internet-based online discussion of key business issues with 50,000 employees. Results were data mined with sophisticated text analysis software (eClassifier) for common themes. Three emerged, expressed as: "Dedication to every client's success", "Innovation that matters—for our company and for the world", and "Trust and personal responsibility in all relationships". Another three-day Jam took place in 2004, with 52,000 employees discussing ways to implement company values in practice.


In 2005, the company sold its personal computer business to Chinese technology company Lenovo, and in the same year it agreed to acquire Micromuse. A year later IBM launched Secure Blue, a low-cost hardware design for data encryption that can be built into a microprocessor. In 2009 it acquired software company SPSS Inc. Later in 2009, IBM's Blue Gene supercomputing program was awarded the National Medal of Technology and Innovation by U.S. President Barack Obama. In 2011, IBM gained worldwide attention for its artificial intelligence program Watson, which was exhibited on Jeopardy! where it won against game-show champions Ken Jennings and Brad Rutter. As of 2012[update], IBM had been the top annual recipient of U.S. patents for 20 consecutive years.


On October 28, 2015, IBM announced its acquisition of digital assets from The Weather Company—a holding company of Bain Capital, The Blackstone Group and NBCUniversal which owns The Weather Channel, including its weather data platforms (such as Weather Services International), websites (Weather.com and Weather Underground) and mobile apps. The acquisition seeks to use Watson for weather analytics and predictions. The acquisition does not include The Weather Channel itself, which will enter into a long-term licensing agreement with IBM for use of its data. The sale closed on January 29, 2016


The company's 14 member Board of Directors is responsible for overall corporate management. As of Cathie Black's resignation in November 2010 its membership (by affiliation and year of joining) included: Alain J. P. Belda '08 (Alcoa), William R. Brody '07 (Salk Institute / Johns Hopkins University), Kenneth Chenault '98 (American Express), Michael L. Eskew '05 (UPS), Shirley Ann Jackson '05 (Rensselaer Polytechnic Institute), Andrew N. Liveris '10 (Dow Chemical), W. James McNerney, Jr. '09 (Boeing), James W. Owens '06 (Caterpillar), Samuel J. Palmisano '00 (IBM), Joan Spero '04 (Doris Duke Charitable Foundation), Sidney Taurel '01 (Eli Lilly), and Lorenzo Zambrano '03 (Cemex).


On January 21, 2014 IBM announced that company executives would forgo bonuses for fiscal year 2013. The move came as the firm reported a 5% drop in sales and 1% decline in net profit over 2012. It also committed to a $1.2bn plus expansion of its data center and cloud-storage business, including the development of 15 new data centers. After ten successive quarters of flat or sliding sales under Chief Executive Virginia Rometty IBM is being forced to look at new approaches. Said Rometty, “We’ve got to reinvent ourselves like we’ve done in prior generations.”


Other major campus installations include towers in Montreal, Paris, and Atlanta; software labs in Raleigh-Durham, Rome, Cracow and Toronto; Johannesburg, Seattle; and facilities in Hakozaki and Yamato. The company also operates the IBM Scientific Center, Hursley House, the Canada Head Office Building, IBM Rochester, and the Somers Office Complex. The company's contributions to architecture and design, which include works by Eero Saarinen, Ludwig Mies van der Rohe, and I.M. Pei, have been recognized. Van der Rohe's 330 North Wabash building in Chicago, the original center of the company's research division post-World War II, was recognized with the 1990 Honor Award from the National Building Museum.


IBM's employee management practices can be traced back to its roots. In 1914, CEO Thomas J. Watson boosted company spirit by creating employee sports teams, hosting family outings, and furnishing a company band. IBM sports teams still continue in the present day; the IBM Big Blue continue to exist as semi-professional company rugby and American football teams. In 1924 the Quarter Century Club, which recognizes employees with 25 years of service, was organized and the first issue of Business Machines, IBM's internal publication, was published. In 1925, the first meeting of the Hundred Percent Club, composed of IBM salesmen who meet their quotas, convened in Atlantic City, New Jersey.


IBM was among the first corporations to provide group life insurance (1934), survivor benefits (1935) and paid vacations (1937). In 1932 IBM created an Education Department to oversee training for employees, which oversaw the completion of the IBM Schoolhouse at Endicott in 1933. In 1935, the employee magazine Think was created. Also that year, IBM held its first training class for female systems service professionals. In 1942, IBM launched a program to train and employ disabled people in Topeka, Kansas. The next year classes began in New York City, and soon the company was asked to join the President's Committee for Employment of the Handicapped. In 1946, the company hired its first black salesman, 18 years before the Civil Rights Act of 1964. In 1947, IBM announced a Total and Permanent Disability Income Plan for employees. A vested rights pension was added to the IBM retirement plan. During IBM's management transformation in the 1990s revisions were made to these pension plans to reduce IBM's pension liabilities.


In 1952, Thomas J. Watson, Jr., published the company's first written equal opportunity policy letter, one year before the U.S. Supreme Court decision in Brown vs. Board of Education and 11 years before the Civil Rights Act of 1964. In 1961, IBM's nondiscrimination policy was expanded to include sex, national origin, and age. The following year, IBM hosted its first Invention Award Dinner honoring 34 outstanding IBM inventors; and in 1963, the company named the first eight IBM Fellows in a new Fellowship Program that recognizes senior IBM scientists, engineers and other professionals for outstanding technical achievements.


On September 21, 1953, Thomas Watson, Jr., the company's president at the time, sent out a controversial letter to all IBM employees stating that IBM needed to hire the best people, regardless of their race, ethnic origin, or gender. He also publicized the policy so that in his negotiations to build new manufacturing plants with the governors of two states in the U.S. South, he could be clear that IBM would not build "separate-but-equal" workplaces. In 1984, IBM added sexual orientation to its nondiscrimination policy. The company stated that this would give IBM a competitive advantage because IBM would then be able to hire talented people its competitors would turn down.


IBM has been a leading proponent of the Open Source Initiative, and began supporting Linux in 1998. The company invests billions of dollars in services and software based on Linux through the IBM Linux Technology Center, which includes over 300 Linux kernel developers. IBM has also released code under different open source licenses, such as the platform-independent software framework Eclipse (worth approximately US$40 million at the time of the donation), the three-sentence International Components for Unicode (ICU) license, and the Java-based relational database management system (RDBMS) Apache Derby. IBM's open source involvement has not been trouble-free, however (see SCO v. IBM).


DeveloperWorks is a website run by IBM for software developers and IT professionals. It contains how-to articles and tutorials, as well as software downloads and code samples, discussion forums, podcasts, blogs, wikis, and other resources for developers and technical professionals. Subjects range from open, industry-standard technologies like Java, Linux, SOA and web services, web development, Ajax, PHP, and XML to IBM's products (WebSphere, Rational, Lotus, Tivoli and Information Management). In 2007, developerWorks was inducted into the Jolt Hall of Fame.


Virtually all console gaming systems of the previous generation used microprocessors developed by IBM. The Xbox 360 contains a PowerPC tri-core processor, which was designed and produced by IBM in less than 24 months. Sony's PlayStation 3 features the Cell BE microprocessor designed jointly by IBM, Toshiba, and Sony. IBM also provided the microprocessor that serves as the heart of Nintendo's new Wii U system, which debuted in 2012. The new Power Architecture-based microprocessor includes IBM's latest technology in an energy-saving silicon package. Nintendo's seventh-generation console, Wii, features an IBM chip codenamed Broadway. The older Nintendo GameCube utilizes the Gekko processor, also designed by IBM.


IBM announced it will launch its new software, called "Open Client Offering" which is to run on Linux, Microsoft Windows and Apple's Mac OS X. The company states that its new product allows businesses to offer employees a choice of using the same software on Windows and its alternatives. This means that "Open Client Offering" is to cut costs of managing whether to use Linux or Apple relative to Windows. There will be no necessity for companies to pay Microsoft for its licenses for operating systems since the operating systems will no longer rely on software which is Windows-based. One alternative to Microsoft's office document formats is the Open Document Format software, whose development IBM supports. It is going to be used for several tasks like: word processing, presentations, along with collaboration with Lotus Notes, instant messaging and blog tools as well as an Internet Explorer competitor – the Mozilla Firefox web browser. IBM plans to install Open Client on 5% of its desktop PCs. The Linux offering has been made available as the IBM Client for Smart Work product on the Ubuntu and Red Hat Enterprise Linux platforms.


In 2006, IBM launched Secure Blue, encryption hardware that can be built into microprocessors. A year later, IBM unveiled Project Big Green, a re-direction of $1 billion per year across its businesses to increase energy efficiency. On November 2008, IBM’s CEO, Sam Palmisano, during a speech at the Council on Foreign Relations, outlined a new agenda for building a Smarter Planet. On March 1, 2011, IBM announced the Smarter Computing framework to support Smarter Planet. On Aug 18, 2011, as part of its effort in cognitive computing, IBM has produced chips that imitate neurons and synapses. These microprocessors do not use von Neumann architecture, and they consume less memory and power.


IBM also holds the SmartCamp program globally. The program searches for fresh start-up companies that IBM can partner with to solve world problems. IBM holds 17 SmartCamp events around the world. Since July 2011, IBM has partnered with Pennies, the electronic charity box, and produced a software solution for IBM retail customers that provides an easy way to donate money when paying in-store by credit or debit card. Customers donate just a few pence (1p-99p) a time and every donation goes to UK charities.


The birthplace of IBM, Endicott, suffered pollution for decades, however. IBM used liquid cleaning agents in circuit board assembly operation for more than two decades, and six spills and leaks were recorded, including one leak in 1979 of 4,100 gallons from an underground tank. These left behind volatile organic compounds in the town's soil and aquifer. Traces of volatile organic compounds have been identified in Endicott’s drinking water, but the levels are within regulatory limits. Also, from 1980, IBM has pumped out 78,000 gallons of chemicals, including trichloroethane, freon, benzene and perchloroethene to the air and allegedly caused several cancer cases among the townspeople. IBM Endicott has been identified by the Department of Environmental Conservation as the major source of pollution, though traces of contaminants from a local dry cleaner and other polluters were also found. Remediation and testing are ongoing, however according to city officials, tests show that the water is safe to drink.


In physics, energy is a property of objects which can be transferred to other objects or converted into different forms. The "ability of a system to perform work" is a common description, but it is difficult to give one single comprehensive definition of energy because of its many forms. For instance, in SI units, energy is measured in joules, and one joule is defined "mechanically", being the energy transferred to an object by the mechanical work of moving it a distance of 1 metre against a force of 1 newton.[note 1] However, there are many other definitions of energy, depending on the context, such as thermal energy, radiant energy, electromagnetic, nuclear, etc., where definitions are derived that are the most convenient.


Common energy forms include the kinetic energy of a moving object, the potential energy stored by an object's position in a force field (gravitational, electric or magnetic), the elastic energy stored by stretching solid objects, the chemical energy released when a fuel burns, the radiant energy carried by light, and the thermal energy due to an object's temperature. All of the many forms of energy are convertible to other kinds of energy. In Newtonian physics, there is a universal law of conservation of energy which says that energy can be neither created nor be destroyed; however, it can change from one form to another.


For "closed systems" with no external source or sink of energy, the first law of thermodynamics states that a system's energy is constant unless energy is transferred in or out by mechanical work or heat, and that no energy is lost in transfer. This means that it is impossible to create or destroy energy. While heat can always be fully converted into work in a reversible isothermal expansion of an ideal gas, for cyclic processes of practical interest in heat engines the second law of thermodynamics states that the system doing work always loses some energy as waste heat. This creates a limit to the amount of heat energy that can do work in a cyclic process, a limit called the available energy. Mechanical and other forms of energy can be transformed in the other direction into thermal energy without such limitations. The total energy of a system can be calculated by adding up all forms of energy in the system.


Examples of energy transformation include generating electric energy from heat energy via a steam turbine, or lifting an object against gravity using electrical energy driving a crane motor. Lifting against gravity performs mechanical work on the object and stores gravitational potential energy in the object. If the object falls to the ground, gravity does mechanical work on the object which transforms the potential energy in the gravitational field to the kinetic energy released as heat on impact with the ground. Our Sun transforms nuclear potential energy to other forms of energy; its total mass does not decrease due to that in itself (since it still contains the same total energy even if in different forms), but its mass does decrease when the energy escapes out to its surroundings, largely as radiant energy.


The total energy of a system can be subdivided and classified in various ways. For example, classical mechanics distinguishes between kinetic energy, which is determined by an object's movement through space, and potential energy, which is a function of the position of an object within a field. It may also be convenient to distinguish gravitational energy, thermal energy, several types of nuclear energy (which utilize potentials from the nuclear force and the weak force), electric energy (from the electric field), and magnetic energy (from the magnetic field), among others. Many of these classifications overlap; for instance, thermal energy usually consists partly of kinetic and partly of potential energy.


Some types of energy are a varying mix of both potential and kinetic energy. An example is mechanical energy which is the sum of (usually macroscopic) kinetic and potential energy in a system. Elastic energy in materials is also dependent upon electrical potential energy (among atoms and molecules), as is chemical energy, which is stored and released from a reservoir of electrical potential energy between electrons, and the molecules or atomic nuclei that attract them.[need quotation to verify].The list is also not necessarily complete. Whenever physical scientists discover that a certain phenomenon appears to violate the law of energy conservation, new forms are typically added that account for the discrepancy.


In the late 17th century, Gottfried Leibniz proposed the idea of the Latin: vis viva, or living force, which defined as the product of the mass of an object and its velocity squared; he believed that total vis viva was conserved. To account for slowing due to friction, Leibniz theorized that thermal energy consisted of the random motion of the constituent parts of matter, a view shared by Isaac Newton, although it would be more than a century until this was generally accepted. The modern analog of this property, kinetic energy, differs from vis viva only by a factor of two.


In 1807, Thomas Young was possibly the first to use the term "energy" instead of vis viva, in its modern sense. Gustave-Gaspard Coriolis described "kinetic energy" in 1829 in its modern sense, and in 1853, William Rankine coined the term "potential energy". The law of conservation of energy was also first postulated in the early 19th century, and applies to any isolated system. It was argued for some years whether heat was a physical substance, dubbed the caloric, or merely a physical quantity, such as momentum. In 1845 James Prescott Joule discovered the link between mechanical work and the generation of heat.


These developments led to the theory of conservation of energy, formalized largely by William Thomson (Lord Kelvin) as the field of thermodynamics. Thermodynamics aided the rapid development of explanations of chemical processes by Rudolf Clausius, Josiah Willard Gibbs, and Walther Nernst. It also led to a mathematical formulation of the concept of entropy by Clausius and to the introduction of laws of radiant energy by Jožef Stefan. According to Noether's theorem, the conservation of energy is a consequence of the fact that the laws of physics do not change over time. Thus, since 1918, theorists have understood that the law of conservation of energy is the direct mathematical consequence of the translational symmetry of the quantity conjugate to energy, namely time.


Another energy-related concept is called the Lagrangian, after Joseph-Louis Lagrange. This formalism is as fundamental as the Hamiltonian, and both can be used to derive the equations of motion or be derived from them. It was invented in the context of classical mechanics, but is generally useful in modern physics. The Lagrangian is defined as the kinetic energy minus the potential energy. Usually, the Lagrange formalism is mathematically more convenient than the Hamiltonian for non-conservative systems (such as systems with friction).


Noether's theorem (1918) states that any differentiable symmetry of the action of a physical system has a corresponding conservation law. Noether's theorem has become a fundamental tool of modern theoretical physics and the calculus of variations. A generalisation of the seminal formulations on constants of motion in Lagrangian and Hamiltonian mechanics (1788 and 1833, respectively), it does not apply to systems that cannot be modeled with a Lagrangian; for example, dissipative systems with continuous symmetries need not have a corresponding conservation law.


In the context of chemistry, energy is an attribute of a substance as a consequence of its atomic, molecular or aggregate structure. Since a chemical transformation is accompanied by a change in one or more of these kinds of structure, it is invariably accompanied by an increase or decrease of energy of the substances involved. Some energy is transferred between the surroundings and the reactants of the reaction in the form of heat or light; thus the products of a reaction may have more or less energy than the reactants. A reaction is said to be exergonic if the final state is lower on the energy scale than the initial state; in the case of endergonic reactions the situation is the reverse. Chemical reactions are invariably not possible unless the reactants surmount an energy barrier known as the activation energy. The speed of a chemical reaction (at given temperature T) is related to the activation energy E, by the Boltzmann's population factor e−E/kT – that is the probability of molecule to have energy greater than or equal to E at the given temperature T. This exponential dependence of a reaction rate on temperature is known as the Arrhenius equation.The activation energy necessary for a chemical reaction can be in the form of thermal energy.


In biology, energy is an attribute of all biological systems from the biosphere to the smallest living organism. Within an organism it is responsible for growth and development of a biological cell or an organelle of a biological organism. Energy is thus often said to be stored by cells in the structures of molecules of substances such as carbohydrates (including sugars), lipids, and proteins, which release energy when reacted with oxygen in respiration. In human terms, the human equivalent (H-e) (Human energy conversion) indicates, for a given amount of energy expenditure, the relative quantity of energy needed for human metabolism, assuming an average human energy expenditure of 12,500 kJ per day and a basal metabolic rate of 80 watts. For example, if our bodies run (on average) at 80 watts, then a light bulb running at 100 watts is running at 1.25 human equivalents (100 ÷ 80) i.e. 1.25 H-e. For a difficult task of only a few seconds' duration, a person can put out thousands of watts, many times the 746 watts in one official horsepower. For tasks lasting a few minutes, a fit human can generate perhaps 1,000 watts. For an activity that must be sustained for an hour, output drops to around 300; for an activity kept up all day, 150 watts is about the maximum. The human equivalent assists understanding of energy flows in physical and biological systems by expressing energy units in human terms: it provides a "feel" for the use of a given amount of energy.


Sunlight is also captured by plants as chemical potential energy in photosynthesis, when carbon dioxide and water (two low-energy compounds) are converted into the high-energy compounds carbohydrates, lipids, and proteins. Plants also release oxygen during photosynthesis, which is utilized by living organisms as an electron acceptor, to release the energy of carbohydrates, lipids, and proteins. Release of the energy stored during photosynthesis as heat or light may be triggered suddenly by a spark, in a forest fire, or it may be made available more slowly for animal or human metabolism, when these molecules are ingested, and catabolism is triggered by enzyme action.


Any living organism relies on an external source of energy—radiation from the Sun in the case of green plants, chemical energy in some form in the case of animals—to be able to grow and reproduce. The daily 1500–2000 Calories (6–8 MJ) recommended for a human adult are taken as a combination of oxygen and food molecules, the latter mostly carbohydrates and fats, of which glucose (C6H12O6) and stearin (C57H110O6) are convenient examples. The food molecules are oxidised to carbon dioxide and water in the mitochondria


It would appear that living organisms are remarkably inefficient (in the physical sense) in their use of the energy they receive (chemical energy or radiation), and it is true that most real machines manage higher efficiencies. In growing organisms the energy that is converted to heat serves a vital purpose, as it allows the organism tissue to be highly ordered with regard to the molecules it is built from. The second law of thermodynamics states that energy (and matter) tends to become more evenly spread out across the universe: to concentrate energy (or matter) in one specific place, it is necessary to spread out a greater amount of energy (as heat) across the remainder of the universe ("the surroundings").[note 3] Simpler organisms can achieve higher energy efficiencies than more complex ones, but the complex organisms can occupy ecological niches that are not available to their simpler brethren. The conversion of a portion of the chemical energy to heat at each step in a metabolic pathway is the physical reason behind the pyramid of biomass observed in ecology: to take just the first step in the food chain, of the estimated 124.7 Pg/a of carbon that is fixed by photosynthesis, 64.3 Pg/a (52%) are used for the metabolism of green plants, i.e. reconverted into carbon dioxide and heat.


Sunlight may be stored as gravitational potential energy after it strikes the Earth, as (for example) water evaporates from oceans and is deposited upon mountains (where, after being released at a hydroelectric dam, it can be used to drive turbines or generators to produce electricity). Sunlight also drives many weather phenomena, save those generated by volcanic events. An example of a solar-mediated weather event is a hurricane, which occurs when large unstable areas of warm ocean, heated over months, give up some of their thermal energy suddenly to power a few days of violent air movement.


In a slower process, radioactive decay of atoms in the core of the Earth releases heat. This thermal energy drives plate tectonics and may lift mountains, via orogenesis. This slow lifting represents a kind of gravitational potential energy storage of the thermal energy, which may be later released to active kinetic energy in landslides, after a triggering event. Earthquakes also release stored elastic potential energy in rocks, a store that has been produced ultimately from the same radioactive heat sources. Thus, according to present understanding, familiar events such as landslides and earthquakes release energy that has been stored as potential energy in the Earth's gravitational field or elastic strain (mechanical potential energy) in rocks. Prior to this, they represent release of energy that has been stored in heavy atoms since the collapse of long-destroyed supernova stars created these atoms.


In cosmology and astronomy the phenomena of stars, nova, supernova, quasars and gamma-ray bursts are the universe's highest-output energy transformations of matter. All stellar phenomena (including solar activity) are driven by various kinds of energy transformations. Energy in such transformations is either from gravitational collapse of matter (usually molecular hydrogen) into various classes of astronomical objects (stars, black holes, etc.), or from nuclear fusion (of lighter elements, primarily hydrogen). The nuclear fusion of hydrogen in the Sun also releases another store of potential energy which was created at the time of the Big Bang. At that time, according to theory, space expanded and the universe cooled too rapidly for hydrogen to completely fuse into heavier elements. This meant that hydrogen represents a store of potential energy that can be released by fusion. Such a fusion process is triggered by heat and pressure generated from gravitational collapse of hydrogen clouds when they produce stars, and some of the fusion energy is then transformed into sunlight.


In quantum mechanics, energy is defined in terms of the energy operator as a time derivative of the wave function. The Schrödinger equation equates the energy operator to the full energy of a particle or a system. Its results can be considered as a definition of measurement of energy in quantum mechanics. The Schrödinger equation describes the space- and time-dependence of a slowly changing (non-relativistic) wave function of quantum systems. The solution of this equation for a bound system is discrete (a set of permitted states, each characterized by an energy level) which results in the concept of quanta. In the solution of the Schrödinger equation for any oscillator (vibrator) and for electromagnetic waves in a vacuum, the resulting energy states are related to the frequency by Planck's relation:  (where  is Planck's constant and  the frequency). In the case of an electromagnetic wave these energy states are called quanta of light or photons.


For example, consider electron–positron annihilation, in which the rest mass of individual particles is destroyed, but the inertia equivalent of the system of the two particles (its invariant mass) remains (since all energy is associated with mass), and this inertia and invariant mass is carried off by photons which individually are massless, but as a system retain their mass. This is a reversible process – the inverse process is called pair creation – in which the rest mass of particles is created from energy of two (or more) annihilating photons. In this system the matter (electrons and positrons) is destroyed and changed to non-matter energy (the photons). However, the total system mass and energy do not change during this interaction.


There are strict limits to how efficiently heat can be converted into work in a cyclic process, e.g. in a heat engine, as described by Carnot's theorem and the second law of thermodynamics. However, some energy transformations can be quite efficient. The direction of transformations in energy (what kind of energy is transformed to what other kind) is often determined by entropy (equal energy spread among all available degrees of freedom) considerations. In practice all energy transformations are permitted on a small scale, but certain larger transformations are not permitted because it is statistically unlikely that energy or matter will randomly move into more concentrated forms or smaller spaces.