In academic publishing, a scientific journal is a periodical publication intended to further the progress of science by reporting new research. Articles in scientific journals are written by active scientists such as students and professors instead of professional journalists. There are thousands of scientific journals in publication, many more have been published at various points in the past. Most journals are specialized, although some of the oldest journals such as Nature publish articles and scientific papers across a wide range of scientific fields. Scientific journals contain articles that have been peer reviewed, in an attempt to ensure that articles meet the journal's standards of quality, scientific validity. Although scientific journals are superficially similar to professional magazines, they are quite different. Issues of a scientific journal are read casually, as one would read a magazine; the publication of the results of research is an essential part of the scientific method. If they are describing experiments or calculations, they must supply enough details that an independent researcher could repeat the experiment or calculation to verify the results.
Each such journal article becomes part of the permanent scientific record. Articles in scientific journals can be used in higher education. Scientific articles allow researchers to keep up to date with the developments of their field and direct their own research. An essential part of a scientific article is citation of earlier work; the impact of articles and journals is assessed by counting citations. Some classes are devoted to the explication of classic articles, seminar classes can consist of the presentation by each student of a classic or current paper. Schoolbooks and textbooks have been written only on established topics, while the latest research and more obscure topics are only accessible through scientific articles. In a scientific research group or academic department it is usual for the content of current scientific journals to be discussed in journal clubs. Public funding bodies require the results to be published in scientific journals. Academic credentials for promotion into academic ranks are established in large part by the number and impact of scientific articles published.
Many doctoral programs allow for thesis by publication, where the candidate is required to publish a certain number of scientific articles. Articles tend to be technical, representing the latest theoretical research and experimental results in the field of science covered by the journal, they are incomprehensible to anyone except for researchers in the field and advanced students. In some subjects this is inevitable given the nature of the content. Rigorous rules of scientific writing are enforced by the editors. Articles are either original articles reporting new results or reviews of current literature. There are scientific publications that bridge the gap between articles and books by publishing thematic volumes of chapters from different authors. Many journals have a regional focus, specializing in publishing papers from a particular geographic region, like African Invertebrates; the history of scientific journals dates from 1665, when the French Journal des sçavans and the English Philosophical Transactions of the Royal Society first began systematically publishing research results.
Over a thousand ephemeral, were founded in the 18th century, the number has increased after that. Prior to mid-20th century, peer review was not always necessary, but it became compulsory; the authors of scientific articles are active researchers instead of journalists. As such, the authors receive no compensation from the journal. However, their funding bodies may require them to publish in scientific journals; the paper is submitted to the journal office, where the editor considers the paper for appropriateness, potential scientific impact and novelty. If the journal's editor considers the paper appropriate, the paper is submitted to scholarly peer review. Depending on the field and paper, the paper is sent to 1–3 reviewers for evaluation before they can be granted permission to publish. Reviewers are expected to check the paper for soundness of its scientific argument, i.e. if the data collected or considered in the paper support the conclusion offered. Novelty is key: existing work must be appropriately considered and referenced, new results improving on the state of the art presented.
Reviewers are unpaid and not a part of the journal staff—instead, they should be "peers", i.e. researchers in the same field as the paper in question. The standards that a journal uses to determine publication can vary widely; some journals, such as Nature, Science, PNAS, Physical Review Letters, have a reputation of publishing articles that mark a fundamental breakthrough in their respective fields. In many fields, a formal or informal hierarchy of scientific journals exists. In some countries, journal rankings can be utilized for funding decisions and evaluation of individual researchers, although they are poorly suited for that purpose. For scientific journals Reproducibility and Replicability are core concepts that allow other scientists to check and reproduce the results under the same conditions described
International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
The Solar System is the gravitationally bound planetary system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, such as the five dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury; the Solar System formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system's mass is in the Sun, with the majority of the remaining mass contained in Jupiter; the four smaller inner planets, Venus and Mars, are terrestrial planets, being composed of rock and metal. The four outer planets are giant planets, being more massive than the terrestrials; the two largest and Saturn, are gas giants, being composed of hydrogen and helium. All eight planets have circular orbits that lie within a nearly flat disc called the ecliptic.
The Solar System contains smaller objects. The asteroid belt, which lies between the orbits of Mars and Jupiter contains objects composed, like the terrestrial planets, of rock and metal. Beyond Neptune's orbit lie the Kuiper belt and scattered disc, which are populations of trans-Neptunian objects composed of ices, beyond them a newly discovered population of sednoids. Within these populations are several dozen to tens of thousands of objects large enough that they have been rounded by their own gravity; such objects are categorized as dwarf planets. Identified dwarf planets include the trans-Neptunian objects Pluto and Eris. In addition to these two regions, various other small-body populations, including comets and interplanetary dust clouds travel between regions. Six of the planets, at least four of the dwarf planets, many of the smaller bodies are orbited by natural satellites termed "moons" after the Moon; each of the outer planets is encircled by planetary rings of dust and other small objects.
The solar wind, a stream of charged particles flowing outwards from the Sun, creates a bubble-like region in the interstellar medium known as the heliosphere. The heliopause is the point at which pressure from the solar wind is equal to the opposing pressure of the interstellar medium; the Oort cloud, thought to be the source for long-period comets, may exist at a distance a thousand times further than the heliosphere. The Solar System is located in the Orion Arm, 26,000 light-years from the center of the Milky Way galaxy. For most of history, humanity did not understand the concept of the Solar System. Most people up to the Late Middle Ages–Renaissance believed Earth to be stationary at the centre of the universe and categorically different from the divine or ethereal objects that moved through the sky. Although the Greek philosopher Aristarchus of Samos had speculated on a heliocentric reordering of the cosmos, Nicolaus Copernicus was the first to develop a mathematically predictive heliocentric system.
In the 17th century, Galileo discovered that the Sun was marked with sunspots, that Jupiter had four satellites in orbit around it. Christiaan Huygens followed on from Galileo's discoveries by discovering Saturn's moon Titan and the shape of the rings of Saturn. Edmond Halley realised in 1705 that repeated sightings of a comet were recording the same object, returning once every 75–76 years; this was the first evidence that anything other than the planets orbited the Sun. Around this time, the term "Solar System" first appeared in English. In 1838, Friedrich Bessel measured a stellar parallax, an apparent shift in the position of a star created by Earth's motion around the Sun, providing the first direct, experimental proof of heliocentrism. Improvements in observational astronomy and the use of unmanned spacecraft have since enabled the detailed investigation of other bodies orbiting the Sun; the principal component of the Solar System is the Sun, a G2 main-sequence star that contains 99.86% of the system's known mass and dominates it gravitationally.
The Sun's four largest orbiting bodies, the giant planets, account for 99% of the remaining mass, with Jupiter and Saturn together comprising more than 90%. The remaining objects of the Solar System together comprise less than 0.002% of the Solar System's total mass. Most large objects in orbit around the Sun lie near the plane of Earth's orbit, known as the ecliptic; the planets are close to the ecliptic, whereas comets and Kuiper belt objects are at greater angles to it. All the planets, most other objects, orbit the Sun in the same direction that the Sun is rotating. There are exceptions, such as Halley's Comet; the overall structure of the charted regions of the Solar System consists of the Sun, four small inner planets surrounded by a belt of rocky asteroids, four giant planets surrounded by the Kuiper belt of icy objects. Astronomers sometimes informally divide this structure into separate regions; the inner Solar System includes the asteroid belt. The outer Solar System is including the four giant planets.
Since the discovery of the Kuiper belt, the outermost parts of the Solar Sys
Geology is an earth science concerned with the solid Earth, the rocks of which it is composed, the processes by which they change over time. Geology can include the study of the solid features of any terrestrial planet or natural satellite such as Mars or the Moon. Modern geology overlaps all other earth sciences, including hydrology and the atmospheric sciences, so is treated as one major aspect of integrated earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, the processes that have shaped that structure, it provides tools to determine the relative and absolute ages of rocks found in a given location, to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, the Earth's past climates. Geologists use a wide variety of methods to understand the Earth's structure and evolution, including field work, rock description, geophysical techniques, chemical analysis, physical experiments, numerical modelling.
In practical terms, geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, providing insights into past climate change. Geology is a major academic discipline, it plays an important role in geotechnical engineering; the majority of geological data comes from research on solid Earth materials. These fall into one of two categories: rock and unlithified material; the majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. There are three major types of rock: igneous and metamorphic; the rock cycle illustrates the relationships among them. When a rock solidifies or crystallizes from melt, it is an igneous rock; this rock can be weathered and eroded redeposited and lithified into a sedimentary rock. It can be turned into a metamorphic rock by heat and pressure that change its mineral content, resulting in a characteristic fabric.
All three types may melt again, when this happens, new magma is formed, from which an igneous rock may once more solidify. To study all three types of rock, geologists evaluate the minerals; each mineral has distinct physical properties, there are many tests to determine each of them. The specimens can be tested for: Luster: Measurement of the amount of light reflected from the surface. Luster is broken into nonmetallic. Color: Minerals are grouped by their color. Diagnostic but impurities can change a mineral’s color. Streak: Performed by scratching the sample on a porcelain plate; the color of the streak can help name the mineral. Hardness: The resistance of a mineral to scratch. Breakage pattern: A mineral can either show fracture or cleavage, the former being breakage of uneven surfaces and the latter a breakage along spaced parallel planes. Specific gravity: the weight of a specific volume of a mineral. Effervescence: Involves dripping hydrochloric acid on the mineral to test for fizzing. Magnetism: Involves using a magnet to test for magnetism.
Taste: Minerals can have a distinctive taste, like halite. Smell: Minerals can have a distinctive odor. For example, sulfur smells like rotten eggs. Geologists study unlithified materials, which come from more recent deposits; these materials are superficial deposits. This study is known as Quaternary geology, after the Quaternary period of geologic history. However, unlithified material does not only include sediments. Magmas and lavas are the original unlithified source of all igneous rocks; the active flow of molten rock is studied in volcanology, igneous petrology aims to determine the history of igneous rocks from their final crystallization to their original molten source. In the 1960s, it was discovered that the Earth's lithosphere, which includes the crust and rigid uppermost portion of the upper mantle, is separated into tectonic plates that move across the plastically deforming, upper mantle, called the asthenosphere; this theory is supported by several types of observations, including seafloor spreading and the global distribution of mountain terrain and seismicity.
There is an intimate coupling between the movement of the plates on the surface and the convection of the mantle. Thus, oceanic plates and the adjoining mantle convection currents always move in the same direction – because the oceanic lithosphere is the rigid upper thermal boundary layer of the convecting mantle; this coupling between rigid plates moving on the surface of the Earth and the convecting mantle is called plate tectonics. The development of plate tectonics has provided a physical basis for many observations of the solid Earth. Long linear regions of geologic features are explained as plate boundaries. For example: Mid-ocean ridges, high regions on the seafloor where hydrothermal vents and volcanoes exist, are seen as divergent boundaries, where two plates move apart. Arcs of volcanoes and earthquakes are theorized as convergent boundaries, where one plate subducts, or moves, under another. Transform boundaries, such as the San Andreas Fault system, resulted in widespread powerful earthquakes.
Plate tectonics has provided a mechan
In Greek mythology, Icarus is the son of the master craftsman Daedalus, the creator of the Labyrinth. Icarus and his father attempt to escape from Crete by means of wings that his father constructed from feathers and wax. Icarus' father warns him first of complacency and of hubris, asking that he fly neither too low nor too high, so the sea's dampness would not clog his wings nor the sun's heat melt them. Icarus ignored; this tragic theme of failure at the hands of hubris contains similarities to that of Phaëthon. Icarus /IK-uh-russ/, Ikaros Ἴκαρος Greek: ‘mallet, chopper’. Compare with ἴκαρ ’at a strike, immediately’ and ἴκρια ‘wooden partition, compartment. Daedalus /DED-uh-luss/, /DEED-uh-luss/, Δαίδαλος anciently /DIGH-dah-lohs/, ‘art, craft, profession’. Icarus's father Daedalus, a talented and remarkable Athenian craftsman, built the Labyrinth for King Minos of Crete near his palace at Knossos to imprison the Minotaur, a half-man, half-bull monster born of his wife and the Cretan bull. Minos imprisoned Daedalus himself in the labyrinth because he gave Minos's daughter, Ariadne, a clew in order to help Theseus, the enemy of Minos, to survive the Labyrinth and defeat the Minotaur.
Daedalus fashioned two pairs of wings out of wax and feathers for his son. Daedalus tried his wings first, but before trying to escape the island, he warned his son not to fly too close to the sun, nor too close to the sea, but to follow his path of flight. Overcome by the giddiness that flying lent him, Icarus soared into the sky, but in the process he came too close to the sun, which due to the heat melted the wax. Icarus kept flapping his wings but soon realized that he had no feathers left and that he was only flapping his bare arms, so Icarus fell into the sea and drowned in the area which today bears his name, the Icarian Sea near Icaria, an island southwest of Samos. Hellenistic writers give euhemerising variants in which the escape from Crete was by boat, provided by Pasiphaë, for which Daedalus invented the first sails, to outstrip Minos' pursuing galleys, that Icarus fell overboard en route to Sicily and drowned. Heracles erected a tomb for him. Icarus' flight was alluded to by Greek poets in passing, but the story was told in Pseudo-Apollodorus.
In the literature of ancient Rome, the myth was of interest to Augustan writers. Hyginus narrates it in Fabula 40, beginning with the bovine love affair of Pasiphaë, daughter of the Sun, resulting in the birth of the Minotaur. Ovid narrates the story of Icarus at some length in the Metamorphoses, refers to it elsewhere. Ovid's treatment of the Icarus myth and its connection with that of Phaëthon influenced the mythological tradition in English literature as received and interpreted by major writers including Chaucer, Shakespeare and Joyce. In Renaissance iconography, the significance of Icarus depends on context: in the Orion Fountain at Messina, he is one of many figures associated with water; the 16th-century painting Landscape with the Fall of Icarus, traditionally but erroneously attributed to Pieter Bruegel the Elder, was the inspiration for two of the 20th century's most notable ecphrastic English-language poems, "Musée des Beaux Arts" by W. H. Auden and "Landscape with the Fall of Icarus" by William Carlos Williams.
Other English language poems referencing the Icarus myth are "To a Friend Whose Work Has Come to Triumph" by Anne Sexton, "Icarus Again" by Alan Devenish, "Mrs Icarus" by Carol Ann Duffy, "Failing and Flying" by Jack Gilbert, "Icarus Burning" and "Icarus Redux" by Hiromi Yoshida. Literary interpretation has found in the myth the structure and consequence of personal over-ambition. An Icarus-related study of the Daedalus myth was published by the French hellenist Françoise Frontisi-Ducroux. In psychology there have been synthetic studies of the Icarus complex with respect to the alleged relationship between fascination for fire, high ambition, ascensionism. In the psychiatric mind features of disease were perceived in the shape of the pendulous emotional ecstatic-high and depressive-low of bipolar disorder. Henry Murray having proposed the term Icarus complex found symptoms in mania where a person is fond of heights, fascinated by both fire and water and observed with fantastical or far-fetched imaginary cognition.
Seth Godin's 2012 The Icarus Deception points to the historical change in how Western culture both propagated and interpreted the Icarus myth arguing that "we tend to forget that Icarus was warned not to fly too low, because seawater would ruin the lift in his wings. Flying too low is more dangerous than flying too high, because it feels deceptively safe." Icarus imagery in contemporary music Kua Fu, a Chinese myth about a giant who chased the sun and died while getting too close Bladud, a legendary king of the Britons, purported to have met his death when his constructed wings failed Etana, a sort of "Babylonian Icarus" Sampati, an Indian myth about a bird which lost its wings while trying to save its younger brother from the sun Graves, Robert, 1960. The Greek Myths, section 92 passim Smith, Willi
Harvard University is a private Ivy League research university in Cambridge, with about 6,700 undergraduate students and about 15,250 postgraduate students. Established in 1636 and named for its first benefactor, clergyman John Harvard, Harvard is the United States' oldest institution of higher learning, its history and wealth have made it one of the world's most prestigious universities; the Harvard Corporation is its first chartered corporation. Although never formally affiliated with any denomination, the early College trained Congregational and Unitarian clergy, its curriculum and student body were secularized during the 18th century, by the 19th century, Harvard had emerged as the central cultural establishment among Boston elites. Following the American Civil War, President Charles W. Eliot's long tenure transformed the college and affiliated professional schools into a modern research university. A. Lawrence Lowell, who followed Eliot, further reformed the undergraduate curriculum and undertook aggressive expansion of Harvard's land holdings and physical plant.
James Bryant Conant led the university through the Great Depression and World War II and began to reform the curriculum and liberalize admissions after the war. The undergraduate college became coeducational after its 1977 merger with Radcliffe College; the university is organized into eleven separate academic units—ten faculties and the Radcliffe Institute for Advanced Study—with campuses throughout the Boston metropolitan area: its 209-acre main campus is centered on Harvard Yard in Cambridge 3 miles northwest of Boston. Harvard's endowment is worth $39.2 billion, making it the largest of any academic institution. Harvard is a large residential research university; the nominal cost of attendance is high, but the university's large endowment allows it to offer generous financial aid packages. The Harvard Library is the world's largest academic and private library system, comprising 79 individual libraries holding over 18 million items; the University is cited as one of the world's top tertiary institutions by various organizations.
Harvard's alumni include eight U. S. presidents, more than thirty foreign heads of state, 62 living billionaires, 359 Rhodes Scholars, 242 Marshall Scholars. As of October 2018, 158 Nobel laureates, 18 Fields Medalists, 14 Turing Award winners have been affiliated as students, faculty, or researchers. In addition, Harvard students and alumni have won 10 Academy Awards, 48 Pulitzer Prizes and 108 Olympic medals, have founded a large number of companies worldwide. Harvard was established in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. In 1638, it acquired British North America's first known printing press. In 1639, it was named Harvard College after deceased clergyman John Harvard, an alumnus of the University of Cambridge, who had left the school £779 and his scholar's library of some 400 volumes; the charter creating the Harvard Corporation was granted in 1650. A 1643 publication gave the school's purpose as "to advance learning and perpetuate it to posterity, dreading to leave an illiterate ministry to the churches when our present ministers shall lie in the dust".
It offered a classic curriculum on the English university model—many leaders in the colony had attended the University of Cambridge—but conformed to the tenets of Puritanism. It was never affiliated with any particular denomination, but many of its earliest graduates went on to become clergymen in Congregational and Unitarian churches; the leading Boston divine Increase Mather served as president from 1685 to 1701. In 1708, John Leverett became the first president, not a clergyman, marking a turning of the college from Puritanism and toward intellectual independence. Throughout the 18th century, Enlightenment ideas of the power of reason and free will became widespread among Congregational ministers, putting those ministers and their congregations in tension with more traditionalist, Calvinist parties; when the Hollis Professor of Divinity David Tappan died in 1803 and the president of Harvard Joseph Willard died a year in 1804, a struggle broke out over their replacements. Henry Ware was elected to the chair in 1805, the liberal Samuel Webber was appointed to the presidency of Harvard two years which signaled the changing of the tide from the dominance of traditional ideas at Harvard to the dominance of liberal, Arminian ideas.
In 1846, the natural history lectures of Louis Agassiz were acclaimed both in New York and on the campus at Harvard College. Agassiz's approach was distinctly idealist and posited Americans' "participation in the Divine Nature" and the possibility of understanding "intellectual existences". Agassiz's perspective on science combined observation with intuition and the assumption that a person can grasp the "divine plan" in all phenomena; when it came to explaining life-forms, Agassiz resorted to matters of shape based on a presumed archetype for his evidence. This dual view of knowledge was in concert with the teachings of Common Sense Realism derived from Scottish philosophers Thomas Reid and Dugald Stewart, whose works were part of the Harvard curriculum at the time; the popularity of Agassiz's efforts to "soar with Plato" also derived from other writings to which Harvard students