A museum is an institution that cares for a collection of artifacts and other objects of artistic, historical, or scientific importance. Many public museums make these items available for public viewing through exhibits that may be permanent or temporary; the largest museums are located in major cities throughout the world, while thousands of local museums exist in smaller cities and rural areas. Museums have varying aims, ranging from serving researchers and specialists to serving the general public; the goal of serving researchers is shifting to serving the general public. There are many types of museums, including art museums, natural history museums, science museums, war museums, children's museums. Amongst the world's largest and most visited museums are the Louvre in Paris, the National Museum of China in Beijing, the Smithsonian Institution in Washington, D. C. the British Museum and National Gallery in London, the Metropolitan Museum of Art in New York City and Vatican Museums in Vatican City.
According to The World Museum Community, there are more than 55,000 museums in 202 countries. The English "museum" comes from the Latin word, is pluralized as "museums", it is from the Ancient Greek Μουσεῖον, which denotes a place or temple dedicated to the Muses, hence a building set apart for study and the arts the Musaeum for philosophy and research at Alexandria by Ptolemy I Soter about 280 BC. The purpose of modern museums is to collect, preserve and display items of artistic, cultural, or scientific significance for the education of the public. From a visitor or community perspective, the purpose can depend on one's point of view. A trip to a local history museum or large city art museum can be an entertaining and enlightening way to spend the day. To city leaders, a healthy museum community can be seen as a gauge of the economic health of a city, a way to increase the sophistication of its inhabitants. To a museum professional, a museum might be seen as a way to educate the public about the museum's mission, such as civil rights or environmentalism.
Museums are, above all, storehouses of knowledge. In 1829, James Smithson's bequest, that would fund the Smithsonian Institution, stated he wanted to establish an institution "for the increase and diffusion of knowledge."Museums of natural history in the late 19th century exemplified the Victorian desire for consumption and for order. Gathering all examples of each classification of a field of knowledge for research and for display was the purpose; as American colleges grew in the 19th century, they developed their own natural history collections for the use of their students. By the last quarter of the 19th century, the scientific research in the universities was shifting toward biological research on a cellular level, cutting edge research moved from museums to university laboratories. While many large museums, such as the Smithsonian Institution, are still respected as research centers, research is no longer a main purpose of most museums. While there is an ongoing debate about the purposes of interpretation of a museum's collection, there has been a consistent mission to protect and preserve artifacts for future generations.
Much care and expense is invested in preservation efforts to retard decomposition in aging documents, artifacts and buildings. All museums display objects; as historian Steven Conn writes, "To see the thing itself, with one's own eyes and in a public place, surrounded by other people having some version of the same experience can be enchanting."Museum purposes vary from institution to institution. Some favor education over conservation, or vice versa. For example, in the 1970s, the Canada Science and Technology Museum favored education over preservation of their objects, they displayed objects as well as their functions. One exhibit featured a historic printing press that a staff member used for visitors to create museum memorabilia; some seek to reach a wide audience, such as a national or state museum, while some museums have specific audiences, like the LDS Church History Museum or local history organizations. Speaking, museums collect objects of significance that comply with their mission statement for conservation and display.
Although most museums do not allow physical contact with the associated artifacts, there are some that are interactive and encourage a more hands-on approach. In 2009, Hampton Court Palace, palace of Henry VIII, opened the council room to the general public to create an interactive environment for visitors. Rather than allowing visitors to handle 500-year-old objects, the museum created replicas, as well as replica costumes; the daily activities, historic clothing, temperature changes immerse the visitor in a slice of what Tudor life may have been. This section lists the 20 most visited museums in 2015 as compiled by AECOM and the Themed Entertainment Association's annual report on the world's most visited attractions. For 2016 figures see List of most visited museums; the cities of London and Washington, D. C. contain more of the 20 most visited museums in the world than any others, with six museums and four museums, respectively. Early museums began as the private collections of wealthy individuals, families or institutions of art and rare or curious natural objects and artifacts.
These were displayed in so-called wonder rooms or cabinets of curiosities. One of the oldest museums known is Ennigaldi-Nanna's museum, built by Princess Ennigaldi at the end of the Neo-Babylonian Empire; the site dates from c. 530 BCE, contained artifacts from earlier M
History of the telescope
The earliest known telescope appeared in 1608 in the Netherlands when an eyeglass maker named Hans Lippershey tried to obtain a patent on one. Although Lippershey did not receive his patent, news of the new invention soon spread across Europe; the design of these early refracting telescopes consisted of a convex objective lens and a concave eyepiece. Galileo applied it to astronomy. In 1611, Johannes Kepler described how a far more useful telescope could be made with a convex objective lens and a convex eyepiece lens and by 1655 astronomers such as Christiaan Huygens were building powerful but unwieldy Keplerian telescopes with compound eyepieces. Isaac Newton is credited with building the first reflector in 1668 with a design that incorporated a small flat diagonal mirror to reflect the light to an eyepiece mounted on the side of the telescope. Laurent Cassegrain in 1672 described the design of a reflector with a small convex secondary mirror to reflect light through a central hole in the main mirror.
The achromatic lens, which reduced color aberrations in objective lenses and allowed for shorter and more functional telescopes, first appeared in a 1733 telescope made by Chester Moore Hall, who did not publicize it. John Dollond learned of Hall's invention and began producing telescopes using it in commercial quantities, starting in 1758. Important developments in reflecting telescopes were John Hadley's production of larger paraboloidal mirrors in 1721; the Ritchey-Chretien variant of Cassegrain reflector was invented around 1910, but not adopted until after 1950. During the period 1850–1900, reflectors suffered from problems with speculum metal mirrors, a considerable number of "Great Refractors" were built from 60 cm to 1 metre aperture, culminating in the Yerkes Observatory refractor in 1897. A number of 4-metre class telescopes were built on superior higher altitude sites including Hawaii and the Chilean desert in the 1975–1985 era; the development of the computer-controlled alt-azimuth mount in the 1970s and active optics in the 1980s enabled a new generation of larger telescopes, starting with the 10-metre Keck telescopes in 1993/1996, a number of 8-metre telescopes including the ESO Very Large Telescope, Gemini Observatory and Subaru Telescope.
The era of radio telescopes was born with Karl Guthe Jansky's serendipitous discovery of an astronomical radio source in 1931. Many types of telescopes were developed in the 20th century for a wide range of wavelengths from radio to gamma-rays; the development of space observatories after 1960 allowed access to several bands impossible to observe from the ground, including X-rays and longer wavelength infrared bands. Objects resembling lenses date back 4000 years although it is unknown if they were used for their optical properties or just as decoration. Greek accounts of the optical properties of water filled spheres followed by many centuries of writings on optics, including Ptolemy in his Optics, who wrote about the properties of light including reflection and color, followed by Ibn Sahl and Ibn Al-Haytham. Actual use of lenses dates back to the widespread manufacture and use of eyeglasses in Northern Italy beginning in the late 13th century; the invention of the use of concave lenses to correct near-sightedness is ascribed to Nicholas of Cusa in 1451.
The first record of a telescope comes from the Netherlands in 1608. It is in a patent filed by Middelburg spectacle-maker Hans Lippershey with the States General of the Netherlands on 2 October 1608 for his instrument "for seeing things far away as if they were nearby". A few weeks another Dutch instrument-maker, Jacob Metius applied for a patent; the States General did not award a patent since the knowledge of the device seemed to be ubiquitous but the Dutch government awarded Lippershey with a contract for copies of his design. The original Dutch telescopes were composed of a convex and a concave lens—telescopes that are constructed this way do not invert the image. Lippershey's original design had only 3x magnification. Telescopes seem to have been made in the Netherlands in considerable numbers soon after this date of "invention", found their way all over Europe. In 1655 Dutch diplomat William de Boreel tried to solve the mystery of, he had a local magistrate in Middelburg follow up on Boreel's childhood and early adult recollections of a spectacle maker named "Hans" who he remembered as the inventor of the telescope.
The magistrate was contacted by a unknown claimant, Middelburg spectacle maker Johannes Zachariassen, who testified that his father, Zacharias Janssen invented the telescope and the microscope as early as 1590. This testimony seemed convincing to Boreel, who now recollected that Zacharias and his father, Hans Martens, must have been who he remembered. Boreel's conclusion that Zacharias Janssen invented the telescope a little ahead of another spectacle maker, Hans Lippershey, was adopted by Pierre Borel in his 1656 book De vero telescopii inventore. Discrepancies in Boreel's investigation and Zacharias
The meridian circle is an instrument for timing of the passage of stars across the local meridian, an event known as a culmination, while at the same time measuring their angular distance from the nadir. These are special purpose telescopes mounted so as to allow pointing only in the meridian, the great circle through the north point of the horizon, the north celestial pole, the zenith, the south point of the horizon, the south celestial pole, the nadir. Meridian telescopes rely on the rotation of the Earth to bring objects into their field of view and are mounted on a fixed, east–west axis; the similar transit instrument, transit circle, or transit telescope is mounted on a horizontal axis, but the axis need not be fixed in the east–west direction. For instance, a surveyor's theodolite can function as a transit instrument if its telescope is capable of a full revolution about the horizontal axis. Meridian circles are called by these names, although they are less specific. For many years, transit timings were the most accurate method of measuring the positions of heavenly bodies, meridian instruments were relied upon to perform this painstaking work.
Before spectroscopy and the perfection of reflecting telescopes, the measuring of positions was the major work of observatories. Fixing a telescope to move only in the meridian has advantages in the high-precision work for which these instruments are employed: The simple mounting is easier to manufacture and maintain to a high precision. At most locations on the Earth, the meridian is the only plane in which celestial coordinates can be indexed directly with such a simple mounting. Revolving the telescope about its axis moves it directly in declination, objects move through its field of view in right ascension. All objects in the sky are subject to the distortion of atmospheric refraction, which tends to make objects appear higher in the sky than they are. At the meridian, this distortion is in declination only, is accounted for; such complex analysis is not conducive to high precision. The state of the art of meridian instruments of the late 19th and early 20th century is described here, giving some idea of the precise methods of construction and adjustment employed.
The earliest transit telescope was not placed in the middle of the axis, but nearer to one end, to prevent the axis from bending under the weight of the telescope. It was placed in the centre of the axis, which consisted of one piece of brass or gun metal with turned cylindrical steel pivots at each end. Several instruments were made of steel, much more rigid than brass; the pivots rested on V-shaped bearings, either set into massive stone or brick piers which supported the instrument, or attached to metal frameworks on the tops of the piers. The temperature of the instrument and local atmosphere were monitored by thermometers; the piers were separate from the foundation of the building, to prevent transmission of vibration from the building to the telescope. To relieve the pivots from the weight of the instrument, which would have distorted their shape and caused rapid wear, each end of the axis was supported by a hook or yoke with friction rollers, suspended from a lever supported by the pier, counterbalanced so as to leave only a small fraction of the weight on the precision V-shaped bearings.
In some cases, the counterweight pushed up on the roller bearings from below. The bearings were set nearly in a true east–west line, but fine adjustment was possible by horizontal and vertical screws. A spirit level was used to monitor for any inclination of the axis to the horizon. Eccentricity or other irregularities of the pivots of the telescope's axis was accounted for, in some cases, by providing another telescope through the axis itself. By observing the motion of an artificial star, located east or west of the center of the main instrument, seen through this axis telescope and a small collimating telescope, as the main telescope was rotated, the shape of the pivots, any wobble of the axis, could be determined. Near each end of the axis, attached to the axis and turning with it, was a circle or wheel for measuring the angle of the telescope to the zenith or horizon. Of 1 to 3 feet or more in diameter, it was divided to 2 or 5 arcminutes, on a slip of silver set into the face of the circle near the circumference.
These graduations were read by microscopes four for each circle, mounted to the piers or a framework surrounding the axis, at 90° intervals around the circles. By averaging the four readings the eccentricity and the errors of graduation were reduced; each microscope was furnished with a micrometer screw, which moved crosshairs, with which the distance of the circle graduations from the centre of the field of view could be measured. The drum of the screw was divided to measure single seconds of arc, while the number of revolutions were counted by a comb like scale in the field of view; the microscopes were given such magnification and placed at such a distance from the circle that one revolution of the micrometer screw corresponded to 1 arcminute on the circle. The error was determined by measuring standard intervals of 2' or 5' on the circle; the periodic errors of the screw were accounted for. On some instruments, one of the circles was graduated and read more coarsely than the other, was used only in finding the target stars.
A seismometer is an instrument that responds to ground motions, such as caused by earthquakes, volcanic eruptions, explosions. Seismometers are combined with a timing device and a recording device to form a seismograph; the output of such a device — recorded on paper or film, now recorded and processed digitally — is a seismogram. Such data is used to locate and characterize earthquakes, to study the earth's internal structure. A simple seismometer, sensitive to up-down motions of the Earth, is like a weight hanging from a spring, both suspended from a frame that moves along with any motion detected; the relative motion between the weight and the frame provides a measurement of the vertical ground motion. A rotating drum is attached to the frame and a pen is attached to the weight, thus recording any ground motion in a seismogram. Any movement of the ground moves the frame; the mass tends not to move because of its inertia, by measuring the movement between the frame and the mass, the motion of the ground can be determined.
Early seismometers used optical levers or mechanical linkages to amplify the small motions involved, recording on soot-covered paper or photographic paper. Modern instruments use electronics. In some systems, the mass is held nearly motionless relative to the frame by an electronic negative feedback loop; the motion of the mass relative to the frame is measured, the feedback loop applies a magnetic or electrostatic force to keep the mass nearly motionless. The voltage needed to produce this force is the output of the seismometer, recorded digitally. In other systems the weight is allowed to move, its motion produces an electrical charge in a coil attached to the mass which voltage moves through the magnetic field of a magnet attached to the frame; this design is used in a geophone, used in exploration for oil and gas. Seismic observatories have instruments measuring three axes: north-south, east-west, vertical. If only one axis is measured, it is the vertical because it is less noisy and gives better records of some seismic waves.
The foundation of a seismic station is critical. A professional station is sometimes mounted on bedrock; the best mountings may be in deep boreholes, which avoid thermal effects, ground noise and tilting from weather and tides. Other instruments are mounted in insulated enclosures on small buried piers of unreinforced concrete. Reinforcing rods and aggregates would distort the pier as the temperature changes. A site is always surveyed for ground noise with a temporary installation before pouring the pier and laying conduit. European seismographs were placed in a particular area after a destructive earthquake. Today, they are concentrated in high-risk regions; the word derives from the Greek σεισμός, seismós, a shaking or quake, from the verb σείω, seíō, to shake. Seismograph is another Greek term from γράφω, gráphō, to draw, it is used to mean seismometer, though it is more applicable to the older instruments in which the measuring and recording of ground motion were combined, than to modern systems, in which these functions are separated.
Both types provide a continuous record of ground motion. The technical discipline concerning such devices is called seismometry, a branch of seismology; the concept of measuring the "shaking" of something means that the word "seismograph" might be used in a more general sense. For example, a monitoring station that tracks changes in electromagnetic noise affecting amateur radio waves presents an rf seismograph, and Helioseismology studies the "quakes" on the Sun. The first seismometer was made in China during the 2nd Century; the first Western description of the device comes from the French physicist and priest Jean de Hautefeuille in 1703. The modern seismometer was developed in the 19th century. In December 2018, a seismometer was deployed on the planet Mars by the InSight lander, the first time a seismometer was placed onto the surface of another planet. In AD 132, Zhang Heng of China's Han dynasty invented the first seismoscope, called Houfeng Didong Yi; the description we have, from the History of the Later Han Dynasty, says that it was a large bronze vessel, about 2 meters in diameter.
When there was an earthquake, one of the dragons' mouths would open and drop its ball into a bronze toad at the base, making a sound and showing the direction of the earthquake. On at least one occasion at the time of a large earthquake in Gansu in AD 143, the seismoscope indicated an earthquake though one was not felt; the available text says that inside the vessel was a central column that could move along eight tracks. The first earthquake recorded by this seismoscope was "somewhere in the east". Days a rider from the east reported this earthquake. By the 13th century, seismographic devices existed in the Maragheh observatory in Persia. French physicist and priest Jean de Hautefeuille built one in 1703. After 1880, most seismometers were descend
A library is a collection of sources of information and similar resources, made accessible to a defined community for reference or borrowing. It provides physical or digital access to material, may be a physical building or room, or a virtual space, or both. A library's collection can include books, newspapers, films, prints, microform, CDs, videotapes, DVDs, Blu-ray Discs, e-books, audiobooks and other formats. Libraries range in size from a few shelves of books to several million items. In Latin and Greek, the idea of a bookcase is represented by Bibliotheca and Bibliothēkē: derivatives of these mean library in many modern languages, e.g. French bibliothèque; the first libraries consisted of archives of the earliest form of writing—the clay tablets in cuneiform script discovered in Sumer, some dating back to 2600 BC. Private or personal libraries made up of written books appeared in classical Greece in the 5th century BC. In the 6th century, at the close of the Classical period, the great libraries of the Mediterranean world remained those of Constantinople and Alexandria.
A library is organized for use and maintained by a public body, an institution, a corporation, or a private individual. Public and institutional collections and services may be intended for use by people who choose not to—or cannot afford to—purchase an extensive collection themselves, who need material no individual can reasonably be expected to have, or who require professional assistance with their research. In addition to providing materials, libraries provide the services of librarians who are experts at finding and organizing information and at interpreting information needs. Libraries provide quiet areas for studying, they often offer common areas to facilitate group study and collaboration. Libraries provide public facilities for access to their electronic resources and the Internet. Modern libraries are being redefined as places to get unrestricted access to information in many formats and from many sources, they are extending services beyond the physical walls of a building, by providing material accessible by electronic means, by providing the assistance of librarians in navigating and analyzing large amounts of information with a variety of digital resources.
Libraries are becoming community hubs where programs are delivered and people engage in lifelong learning. As community centers, libraries are becoming important in helping communities mobilize and organize for their rights; the relationship between librarianship and human rights works to ensure that the rights of cultural minorities, the homeless, the disabled, LGBTQ community, as well as other marginalized groups are not infringed upon as protected in the Universal Declaration of Human Rights. The first libraries consisted of archives of the earliest form of writing—the clay tablets in cuneiform script discovered in temple rooms in Sumer, some dating back to 2600 BC; these archives, which consisted of the records of commercial transactions or inventories, mark the end of prehistory and the start of history. Things were much the same in the temple records on papyrus of Ancient Egypt; the earliest discovered. There is evidence of libraries at Nippur about 1900 BC and those at Nineveh about 700 BC showing a library classification system.
Over 30,000 clay tablets from the Library of Ashurbanipal have been discovered at Nineveh, providing modern scholars with an amazing wealth of Mesopotamian literary and administrative work. Among the findings were the Enuma Elish known as the Epic of Creation, which depicts a traditional Babylonian view of creation; the tablets were stored in a variety of containers such as wooden boxes, woven baskets of reeds, or clay shelves. The "libraries" were cataloged using colophons, which are a publisher's imprint on the spine of a book, or in this case a tablet; the colophons stated the series name, the title of the tablet, any extra information the scribe needed to indicate. The clay tablets were organized by subject and size. Due to limited to bookshelf space, once more tablets were added to the library, older ones were removed, why some tablets are missing from the excavated cities in Mesopotamia. According to legend, mythical philosopher Laozi was keeper of books in the earliest library in China, which belonged to the Imperial Zhou dynasty.
Evidence of catalogues found in some destroyed ancient libraries illustrates the presence of librarians. Persia at the time of the Achaemenid Empire was home to some outstanding libraries; those libraries within the kingdom had two major functions: the first came from the need to keep the records of administrative documents including transactions, governmental orders, budget allocation within and between the Satrapies and the central ruling State. The second function was to collect precious resources on different subjects of science and set of principles e.g. medical science, histor
An equatorial mount is a mount for instruments that compensates for Earth's rotation by having one rotational axis parallel to the Earth's axis of rotation. This type of mount is used for astronomical cameras; the advantage of an equatorial mount lies in its ability to allow the instrument attached to it to stay fixed on any celestial object with diurnal motion by driving one axis at a constant speed. Such an arrangement is called a clock drive. In astronomical telescope mounts, the equatorial axis is paired with a second perpendicular axis of motion; the equatorial axis of the mount is equipped with a motorized "clock drive", that rotates that axis one revolution every 23 hours and 56 minutes in exact sync with the apparent diurnal motion of the sky. They may be equipped with setting circles to allow for the location of objects by their celestial coordinates. Equatorial mounts differ from mechanically simpler altazimuth mounts, which require variable speed motion around both axes to track a fixed object in the sky.
For astrophotography, the image does not rotate in the focal plane, as occurs with altazimuth mounts when they are guided to track the target's motion, unless a rotating erector prism or other field-derotator is installed. Equatorial telescope mounts come in many designs. In the last twenty years motorized tracking has been supplemented with computerized object location. There are two main types. Digital setting circles take a small computer with an object database, attached to encoders; the computer monitors the telescope's position in the sky. The operator must push the telescope. Go-to systems use servo motors and the operator need not touch the instrument at all to change its position in the sky; the computers in these systems are either hand-held in a control "paddle" or supplied through an adjacent laptop computer, used to capture images from an electronic camera. The electronics of modern telescope systems include a port for autoguiding. A special instrument tracks a star and makes adjustment in the telescope's position while photographing the sky.
To do so the autoguider must be able to issue commands through the telescope's control system. These commands can compensate for slight errors in the tracking performance, such as periodic error caused by the worm drive that makes the telescope move. In new observatory designs, equatorial mounts have been out of favor for decades in large-scale professional applications. Massive new instruments are most stable. Computerized tracking and field-derotation are not difficult to implement at the professional level. At the amateur level, equatorial mounts remain popular for astrophotography. In the German equatorial mount, the primary structure is a T-shape, where the lower bar is the right ascension axis, the upper bar is the declination axis; the mount was developed by Joseph von Fraunhofer for the Great Dorpat Refractor, finished in 1824. The telescope is placed on one end of the declination axis, a suitable counterweight on other end of it; the right ascension axis has bearings below the T-joint, that is, it is not supported above the declination axis.
The Open Fork mount has a Fork attached to a right ascension axis at its base. The telescope is attached to two pivot points at the other end of the fork so it can swing in declination. Most modern mass-produced catadioptric reflecting telescopes tend to be of this type; the mount resembles an Altazimuth mount, but with the azimuth axis tilted and lined up to match earth rotation axis with a piece of hardware called a "wedge". Many mid-size professional telescopes have equatorial forks, these are in range of 0.5-2.0 meter diameter. The English mount or Yoke mount has a frame or "yoke" with right ascension axis bearings at the top and the bottom ends, a telescope attached inside the midpoint of the yoke allowing it to swing on the declination axis; the telescope is fitted inside the fork, although there are exceptions such as the Mt. Wilson 2.5 m reflector, there are no counterweights as with the German mount. The original English fork design is disadvantaged in that it does not allow the telescope to point too near the north or south celestial pole.
The Horseshoe mount overcomes the design disadvantage of English or Yoke mounts by replacing the polar bearing with an open "horseshoe" structure to allow the telescope to access Polaris and stars near it. The Hale telescope is the most prominent example of a Horseshoe mount in use; the Cross-axis or English cross. The right ascension axis is supported at both ends, the declination axis is attached to it at midpoint with the telescope on one end of the declination axis and a counter weight on the other. An equatorial platform is a specially designed platform that allows any device sitting on it to track on an equatorial axis, it achieves this by having a surface that pivots about a "virtual polar axis". This gives equatorial tracking to anything sitting on the platform, from small cameras up to entire observatory buildings; these platforms are used with altazimuth mounted amateur astronomical telescopes, such as the common Dobsonian telescope type, to overcome that type of mount's inability to track the night sky.
Altazimuth mount Barn door tracker Equatorial room Hexapod-Telescope List of telescope parts and construction List of telescope types Parallactic angle Polar alignment Polar mount -
South America is a continent in the Western Hemisphere in the Southern Hemisphere, with a small portion in the Northern Hemisphere. It may be considered a subcontinent of the Americas, how it is viewed in the Spanish and Portuguese-speaking regions of the Americas; the reference to South America instead of other regions has increased in the last decades due to changing geopolitical dynamics. It is bordered on the west on the north and east by the Atlantic Ocean, it includes twelve sovereign states, a part of France, a non-sovereign area. In addition to this, the ABC islands of the Kingdom of the Netherlands and Tobago, Panama may be considered part of South America. South America has an area of 17,840,000 square kilometers, its population as of 2016 has been estimated at more than 420 million. South America ranks fourth in fifth in population. Brazil is by far the most populous South American country, with more than half of the continent's population, followed by Colombia, Argentina and Peru. In recent decades Brazil has concentrated half of the region's GDP and has become a first regional power.
Most of the population lives near the continent's western or eastern coasts while the interior and the far south are sparsely populated. The geography of western South America is dominated by the Andes mountains. Most of the continent lies in the tropics; the continent's cultural and ethnic outlook has its origin with the interaction of indigenous peoples with European conquerors and immigrants and, more locally, with African slaves. Given a long history of colonialism, the overwhelming majority of South Americans speak Portuguese or Spanish, societies and states reflect Western traditions. South America occupies the southern portion of the Americas; the continent is delimited on the northwest by the Darién watershed along the Colombia–Panama border, although some may consider the border instead to be the Panama Canal. Geopolitically and geographically all of Panama – including the segment east of the Panama Canal in the isthmus – is included in North America alone and among the countries of Central America.
All of mainland South America sits on the South American Plate. South America is home to Angel Falls in Venezuela. South America's major mineral resources are gold, copper, iron ore and petroleum; these resources found in South America have brought high income to its countries in times of war or of rapid economic growth by industrialized countries elsewhere. However, the concentration in producing one major export commodity has hindered the development of diversified economies; the fluctuation in the price of commodities in the international markets has led to major highs and lows in the economies of South American states causing extreme political instability. This is leading to efforts to diversify production to drive away from staying as economies dedicated to one major export. South America is one of the most biodiverse continents on earth. South America is home to many interesting and unique species of animals including the llama, piranha, vicuña, tapir; the Amazon rainforests possess high biodiversity, containing a major proportion of the Earth's species.
Brazil is the largest country in South America, encompassing around half of the continent's land area and population. The remaining countries and territories are divided among three regions: The Andean States, the Guianas and the Southern Cone. Traditionally, South America includes some of the nearby islands. Aruba, Curaçao, Trinidad and the federal dependencies of Venezuela sit on the northerly South American continental shelf and are considered part of the continent. Geo-politically, the island states and overseas territories of the Caribbean are grouped as a part or subregion of North America, since they are more distant on the Caribbean Plate though San Andres and Providencia are politically part of Colombia and Aves Island is controlled by Venezuela. Other islands that are included with South America are the Galápagos Islands that belong to Ecuador and Easter Island, Robinson Crusoe Island, Chiloé and Tierra del Fuego. In the Atlantic, Brazil owns Fernando de Noronha and Martim Vaz, the Saint Peter and Saint Paul Archipelago, while the Falkland Islands are governed by the United Kingdom, whose sovereignty over the islands is disputed by Argentina.
South Georgia and the South Sandwich Islands may be associate