Astronomy is a natural science that studies celestial objects and phenomena. It applies mathematics and chemistry in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, stars, nebulae and comets. More all phenomena that originate outside Earth's atmosphere are within the purview of astronomy. A related but distinct subject is physical cosmology, the study of the Universe as a whole. Astronomy is one of the oldest of the natural sciences; the early civilizations in recorded history, such as the Babylonians, Indians, Nubians, Chinese and many ancient indigenous peoples of the Americas, performed methodical observations of the night sky. Astronomy has included disciplines as diverse as astrometry, celestial navigation, observational astronomy, the making of calendars, but professional astronomy is now considered to be synonymous with astrophysics. Professional astronomy is split into theoretical branches. Observational astronomy is focused on acquiring data from observations of astronomical objects, analyzed using basic principles of physics.
Theoretical astronomy is oriented toward the development of computer or analytical models to describe astronomical objects and phenomena. The two fields complement each other, with theoretical astronomy seeking to explain observational results and observations being used to confirm theoretical results. Astronomy is one of the few sciences in which amateurs still play an active role in the discovery and observation of transient events. Amateur astronomers have made and contributed to many important astronomical discoveries, such as finding new comets. Astronomy means "law of the stars". Astronomy should not be confused with astrology, the belief system which claims that human affairs are correlated with the positions of celestial objects. Although the two fields share a common origin, they are now distinct. Both of the terms "astronomy" and "astrophysics" may be used to refer to the same subject. Based on strict dictionary definitions, "astronomy" refers to "the study of objects and matter outside the Earth's atmosphere and of their physical and chemical properties," while "astrophysics" refers to the branch of astronomy dealing with "the behavior, physical properties, dynamic processes of celestial objects and phenomena."
In some cases, as in the introduction of the introductory textbook The Physical Universe by Frank Shu, "astronomy" may be used to describe the qualitative study of the subject, whereas "astrophysics" is used to describe the physics-oriented version of the subject. However, since most modern astronomical research deals with subjects related to physics, modern astronomy could be called astrophysics; some fields, such as astrometry, are purely astronomy rather than astrophysics. Various departments in which scientists carry out research on this subject may use "astronomy" and "astrophysics" depending on whether the department is affiliated with a physics department, many professional astronomers have physics rather than astronomy degrees; some titles of the leading scientific journals in this field include The Astronomical Journal, The Astrophysical Journal, Astronomy and Astrophysics. In early historic times, astronomy only consisted of the observation and predictions of the motions of objects visible to the naked eye.
In some locations, early cultures assembled massive artifacts that had some astronomical purpose. In addition to their ceremonial uses, these observatories could be employed to determine the seasons, an important factor in knowing when to plant crops and in understanding the length of the year. Before tools such as the telescope were invented, early study of the stars was conducted using the naked eye; as civilizations developed, most notably in Mesopotamia, Persia, China and Central America, astronomical observatories were assembled and ideas on the nature of the Universe began to develop. Most early astronomy consisted of mapping the positions of the stars and planets, a science now referred to as astrometry. From these observations, early ideas about the motions of the planets were formed, the nature of the Sun and the Earth in the Universe were explored philosophically; the Earth was believed to be the center of the Universe with the Sun, the Moon and the stars rotating around it. This is known as the geocentric model of the Ptolemaic system, named after Ptolemy.
A important early development was the beginning of mathematical and scientific astronomy, which began among the Babylonians, who laid the foundations for the astronomical traditions that developed in many other civilizations. The Babylonians discovered. Following the Babylonians, significant advances in astronomy were made in ancient Greece and the Hellenistic world. Greek astronomy is characterized from the start by seeking a rational, physical explanation for celestial phenomena. In the 3rd century BC, Aristarchus of Samos estimated the size and distance of the Moon and Sun, he proposed a model of the Solar System where the Earth and planets rotated around the Sun, now called the heliocentric model. In the 2nd century BC, Hipparchus discovered precession, calculated the size and distance of the Moon and inven
Saint Paul, Minnesota
Saint Paul is the capital and second-most populous city of the U. S. state of Minnesota. As of 2017, the city's estimated population was 309,180. Saint Paul is the county seat of Ramsey County, the smallest and most densely populated county in Minnesota; the city lies on the east bank of the Mississippi River in the area surrounding its point of confluence with the Minnesota River, adjoins Minneapolis, the state's largest city. Known as the "Twin Cities", the two form the core of Minneapolis–Saint Paul, the 16th-largest metropolitan area in the United States, with about 3.6 million residents. Founded near historic Native American settlements as a trading and transportation center, the city rose to prominence when it was named the capital of the Minnesota Territory in 1849; the Dakota name for Saint Paul is "Imnizaska". Though Minneapolis is better-known nationally, Saint Paul contains the state government and other important institutions. Regionally, the city is known for the Xcel Energy Center, home of the Minnesota Wild, for the Science Museum of Minnesota.
As a business hub of the Upper Midwest, it is the headquarters of companies such as Ecolab. Saint Paul, along with its twin city, Minneapolis, is known for its high literacy rate; the settlement began at present-day Lambert's Landing, but was known as Pig's Eye after Pierre "Pig's Eye" Parrant established a popular tavern there. When Lucien Galtier, the first Catholic pastor of the region, established the Log Chapel of Saint Paul, he made it known that the settlement was now to be called by that name, as "Saint Paul as applied to a town or city was well appropriated, this monosyllable is short, sounds good, it is understood by all Christian denominations". Burial mounds in present-day Indian Mounds Park suggest that the area was inhabited by the Hopewell Native Americans about two thousand years ago. From the early 17th century until 1837, the Mdewakanton Dakota, a tribe of the Sioux, lived near the mounds after fleeing their ancestral home of Mille Lacs Lake from advancing Ojibwe, they called the area I-mni-za ska dan for its exposed white sandstone cliffs.
In the Menominee language it is called Sāēnepān-Menīkān, which means "ribbon, silk or satin village", suggesting its role in trade throughout the region after the introduction of European goods. Following the Louisiana Purchase in 1803, US Army officer Zebulon Pike negotiated 100,000 acres of land from the local Dakota tribes in 1805 to establish a fort; the negotiated territory was located on both banks of the Mississippi River, starting from Saint Anthony Falls in present-day Minneapolis, to its confluence with the Saint Croix River. Fort Snelling was built on the territory in 1819 at the confluence of the Mississippi and Minnesota rivers, which formed a natural barrier to both Native American nations; the 1837 Treaty with the Sioux ceded all local tribal land east of the Mississippi to the U. S. Government. Taoyateduta moved his band at Kaposia across the river to the south. Fur traders and missionaries came to the area for the fort's protection. Many of the settlers were French-Canadians. However, as a whiskey trade flourished, military officers banned settlers from the fort-controlled lands.
Pierre "Pig's Eye" Parrant, a retired fur trader-turned-bootlegger who irritated officials, set up his tavern, the Pig's Eye, near present-day Lambert's Landing. By the early 1840s, the community had become important as a trading center and a destination for settlers heading west. Locals called Pig's Eye Landing after Parrant's popular tavern. In 1841, Father Lucien Galtier was sent to minister to the Catholic French Canadians and established a chapel, named for his favorite saint, Paul the Apostle, on the bluffs above Lambert's Landing. Galtier intended for the settlement to adopt the name Saint Paul in honor of the new chapel. In 1847, a New York educator named Harriet Bishop moved to the area and opened the city's first school; the Minnesota Territory was formalized in Saint Paul named as its capital. In 1857, the territorial legislature voted to move the capital to Saint Peter. However, Joe Rolette, a territorial legislator, stole the physical text of the approved bill and went into hiding, thus preventing the move.
On May 11, 1858, Minnesota was admitted to the union as the thirty-second state, with Saint Paul as the capital. That year, more than 1,000 steamboats were in service at Saint Paul, making the city a gateway for settlers to the Minnesota frontier or Dakota Territory. Natural geography was a primary reason; the area was the last accessible point to unload boats coming upriver due to the Mississippi River Valley's stone bluffs. During this period, Saint Paul was called "The Last City of the East." Industrialist James J. Hill constructed and expanded his network of railways into the Great Northern Railway and Northern Pacific Railway, which were headquartered in Saint Paul. Today they are collectively part of the BNSF Railway. On August 20, 1904, severe thunderstorms and tornadoes damaged hundreds of downtown buildings, causing USD $1.78 million in damages to the city and ripping spans from the High Bridge. In the 1960s, during urban renewal, Saint Paul razed western neighborhoods close to downtown.
The city contended with the creation of the interstate freeway system in a built landscape. From 1959 to 1961, the western Rondo Neighborhood was demolished by the construction of Interstate 94, which brought attention to racial segregation and unequal housing in northern cities; the annual
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geophysical and volcanology are examples of disciplines for which observatories have been constructed. Observatories were as simple as containing an astronomical sextant or Stonehenge. Astronomical observatories are divided into four categories: space-based, ground-based, underground-based. Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes do not have domes.
For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, are at high elevations. At high elevations, the Earth's atmosphere is thinner, thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical "seeing". Sites that meet the above criteria for modern observatories include the southwestern United States, Canary Islands, the Andes, high mountains in Mexico such as Sierra Negra. A newly emerging site which should be added to this list is Mount Gargash. With an elevation of 3600 m above sea level, it is the home to the Iranian National Observatory and its 3.4m INO340 telescope. Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the US, Roque de los Muchachos Observatory and Calar Alto Observatory in Spain, Paranal Observatory in Chile.
Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A — a place in the central part of Eastern Antarctica. This location provides the least atmospheric disturbances and best visibility. Beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to observe the Universe in the radio portion of the electromagnetic spectrum; such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called radio observatories. Radio observatories are located far from major population centers to avoid electromagnetic interference from radio, TV, other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in valleys for further EMI shielding; some of the world's major radio observatories include the Socorro, in New Mexico, United States, Jodrell Bank in the UK, Arecibo in Puerto Rico, Parkes in New South Wales and Chajnantor in Chile.
Since the mid-20th century, a number of astronomical observatories have been constructed at high altitudes, above 4,000–5,000 m. The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a 4,205 m volcano in Hawaiʻi; the Chacaltaya Astrophysical Observatory in Bolivia, at 5,230 m, was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory, an optical-infrared telescope on a remote 5,640 m mountaintop in the Atacama Desert of Chile; the oldest proto-observatories, in the sense of a private observation post, Wurdi Youang, Australia Zorats Karer, Armenia Loughcrew, Ireland Newgrange, Ireland Stonehenge, Great Britain Quito Astronomical Observatory, located 12 minutes south of the Equator in Quito, Ecuador. Chankillo, Peru El Caracol, Mexico Abu Simbel, Egypt Kokino, Republic of Macedonia Observatory at Rhodes, Greece Goseck circle, Germany Ujjain, India Arkaim, Russia Cheomseongdae, South Korea Angkor Wat, CambodiaThe oldest true observatories, in the sense of a specialized research institute, include: 825 AD: Al-Shammisiyyah observatory, Iraq 869: Mahodayapuram Observatory, India 1259: Maragheh observatory, Iran 1276: Gaocheng Astronomical Observatory, China 1420: Ulugh Beg Observatory, Uzbekistan 1442: Beijing Ancient Observatory, China 1577: Constantinople Observatory of Taqi ad-Din, Turkey 1580: Uraniborg, Denmark 1581: Stjerneborg, Denmark 1642: Panzano Observatory, Italy 1642: Round Tower, Denmark 1633: Leiden Observatory, Netherlands 1667: Paris Observatory, France 1675: Royal Greenwich Observatory, England 1695: Sukharev Tower, Russia 1711: Berlin Observatory, Germany 1724: Jantar Mantar, India 1753: Stockholm Observatory, Sweden 1753: Vilnius University Observatory, Lithuania 1753: Navy Royal Institute and Observatory, Spain 1759: Trieste Observatory, Italy 1757: Macfarlane Observatory, Scotland 1759: Turin Observatory, Italy 1764: Brera Astronomical Observatory, Italy 1765: Mohr Observatory, Indonesia 1774: Vatican Observatory, Vatican 1785: Dunsink Observatory, Ireland 1786: Madras Observatory, India 1789: Armagh Observatory, Northern Ireland 1790: Real Observatorio de Madrid, Spain, 1803: National Astronomical Observatory, Bogotá, Colombia.
1811: Tartu Old Observatory, Estonia 1812: Astronomical Observatory of Capodimonte, Italy 1830/1842: Depot of Charts & Instruments
A telescope is an optical instrument that makes distant objects appear magnified by using an arrangement of lenses or curved mirrors and lenses, or various devices used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. The first known practical telescopes were refracting telescopes invented in the Netherlands at the beginning of the 17th century, by using glass lenses, they were used for both terrestrial applications and astronomy. The reflecting telescope, which uses mirrors to collect and focus light, was invented within a few decades of the first refracting telescope. In the 20th century, many new types of telescopes were invented, including radio telescopes in the 1930s and infrared telescopes in the 1960s; the word telescope now refers to a wide range of instruments capable of detecting different regions of the electromagnetic spectrum, in some cases other types of detectors. The word telescope was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei's instruments presented at a banquet at the Accademia dei Lincei.
In the Starry Messenger, Galileo had used the term perspicillum. The earliest existing record of a telescope was a 1608 patent submitted to the government in the Netherlands by Middelburg spectacle maker Hans Lippershey for a refracting telescope; the actual inventor is unknown but word of it spread through Europe. Galileo heard about it and, in 1609, built his own version, made his telescopic observations of celestial objects; the idea that the objective, or light-gathering element, could be a mirror instead of a lens was being investigated soon after the invention of the refracting telescope. The potential advantages of using parabolic mirrors—reduction of spherical aberration and no chromatic aberration—led to many proposed designs and several attempts to build reflecting telescopes. In 1668, Isaac Newton built the first practical reflecting telescope, of a design which now bears his name, the Newtonian reflector; the invention of the achromatic lens in 1733 corrected color aberrations present in the simple lens and enabled the construction of shorter, more functional refracting telescopes.
Reflecting telescopes, though not limited by the color problems seen in refractors, were hampered by the use of fast tarnishing speculum metal mirrors employed during the 18th and early 19th century—a problem alleviated by the introduction of silver coated glass mirrors in 1857, aluminized mirrors in 1932. The maximum physical size limit for refracting telescopes is about 1 meter, dictating that the vast majority of large optical researching telescopes built since the turn of the 20th century have been reflectors; the largest reflecting telescopes have objectives larger than 10 m, work is underway on several 30-40m designs. The 20th century saw the development of telescopes that worked in a wide range of wavelengths from radio to gamma-rays; the first purpose built radio telescope went into operation in 1937. Since a large variety of complex astronomical instruments have been developed; the name "telescope" covers a wide range of instruments. Most detect electromagnetic radiation, but there are major differences in how astronomers must go about collecting light in different frequency bands.
Telescopes may be classified by the wavelengths of light they detect: X-ray telescopes, using shorter wavelengths than ultraviolet light Ultraviolet telescopes, using shorter wavelengths than visible light Optical telescopes, using visible light Infrared telescopes, using longer wavelengths than visible light Submillimetre telescopes, using longer wavelengths than infrared light Fresnel Imager, an optical lens technology X-ray optics, optics for certain X-ray wavelengthsAs wavelengths become longer, it becomes easier to use antenna technology to interact with electromagnetic radiation. The near-infrared can be collected much like visible light, however in the far-infrared and submillimetre range, telescopes can operate more like a radio telescope. For example, the James Clerk Maxwell Telescope observes from wavelengths from 3 μm to 2000 μm, but uses a parabolic aluminum antenna. On the other hand, the Spitzer Space Telescope, observing from about 3 μm to 180 μm uses a mirror. Using reflecting optics, the Hubble Space Telescope with Wide Field Camera 3 can observe in the frequency range from about 0.2 μm to 1.7 μm.
With photons of the shorter wavelengths, with the higher frequencies, glancing-incident optics, rather than reflecting optics are used. Telescopes such as TRACE and SOHO use special mirrors to reflect Extreme ultraviolet, producing higher resolution and brighter images than are otherwise possible. A larger aperture does not just mean that more light is collected, it enables a finer angular resolution. Telescopes may be classified by location: ground telescope, space telescope, or flying telescope, they may be classified by whether they are operated by professional astronomers or amateur astronomers. A vehicle or permanent campus containing one or more telescopes or other instruments is called an observatory. An optical telescope gathers and focuses light from the visible part of the electromagnetic spectrum. Optical telescopes increase the apparent angular size of distant objects as well as their apparent brightness. In order for the image to be observed, photographed and sent to a computer, telescopes work by employing one or
Edward Duffield Neill
Edward Duffield Neill was an American author and educator. Neill was born in Philadelphia. After studying at the University of Pennsylvania for some time, he enrolled at Amherst College and graduated from Amherst in 1842 studied theology at Andover. After ordination as a Presbyterian minister, he moved to St. Paul, Minnesota, in 1848 where he became pastor of the First Presbyterian church, he worked as Superintendent of Public Instruction for the Territory in 1851–53, as chancellor of the State university in 1858–61. During the Civil War he served in the army as a regimental chaplain with the 1st Minnesota Volunteers from 1861 to 1862 and as a hospital chaplain from 1862 to 1863, he worked for Presidents Lincoln and Johnson, who in 1869 nominated him United States Commissioner of Education to replace Henry Barnard, President Grant appointed him Consul to Dublin in 1869. He returned to the United States in 1870, served as the president of Macalester College in St. Paul in 1873–74, thenceforth as professor of history and literature.
He wrote a large number of historical books of the Colonial period. The most important are: History of Minnesota Terra Mariœ, a history of early Maryland History of the Virginia Company of London English Colonization of America during the Seventeenth Century Minnesota Explorers and Pioneers Virginia Vetusta Virginia Carolorum
Macalester College is a private liberal arts college in Saint Paul, Minnesota. Founded in 1874, Macalester is an undergraduate four-year institution and enrolled 2,174 students in the fall of 2018 from 50 U. S. states, 4 U. S territories, the District of Columbia and 97 countries, it is a Forbes Top 100 College, a Forbes Top 50 School for International Students. In 2018, U. S. News & World Report ranked Macalester as 26th best liberal arts college in the United States, 16th for undergraduate teaching at a national liberal arts college, 21st for best value at a national liberal arts college. Macalester College was founded in 1874 by Rev. Dr. Edward Duffield Neill, who served as a chaplain in the Civil War and held positions in three U. S. presidential administrations. After journeying to the Minnesota Territory in 1849 to do missionary work, he founded two churches and served as the state’s first superintendent of public education and first chancellor of the University of Minnesota, he planned a college that would be Presbyterian-affiliated but nonsectarian, making it inclusive by the standards of his day.
Charles Macalester, a prominent businessman and philanthropist from Philadelphia, made the establishing gift by donating the Winslow House, a noted summer hotel in Minneapolis. With additional funding from the Presbyterian Church and from the new College’s trustees, Macalester opened in 1885 with five professors, six freshmen, 52 preparatory students. In 1887, a classical scholar named James Wallace joined the faculty and established himself as a fine and demanding teacher, he earned a national reputation for scholarship when he published two Greek textbooks that were used across the country. In spite of academic success, James Wallace’s early years at Macalester were financially difficult, his efforts built up a group of donors whose support, together with tuition from a growing student body, put the college on steady footing. By the time he rejoined the faculty in 1906, Wallace had enabled the college to pay off its debt, maintain a balanced budget, begin to establish an endowment to offer some protection against hard times.
In the 1940s and 1950s President Charles J. Turck gave new emphasis to the College’s internationalism by recruiting foreign students, creating overseas study opportunities, hiring faculty from diverse backgrounds; the College engaged in a period of advancement throughout the 1960s, made possible by DeWitt and Lila Wallace, founders of Reader’s Digest and benefactors of Macalester. Under the leadership of President Harvey M. Rice, the College strengthened the academic credentials of its faculty, enhanced academic programming, attracting more students to the small liberal arts college. A major building campaign resulted in new science facilities. During this time, Macalester committed itself to a liberal arts curriculum; the 1990s were another period of advancement for Macalester. In 1991, the College’s endowment became larger than it had been; the College increased the number of faculty positions, adding more broadly diverse perspectives to the educational program. The improved student-faculty ratio made possible more flexible and personalized teaching approaches, including significant enhancement of faculty-student collaborative research and writing.
Through a comprehensive campus improvement program and residential buildings on campus was renovated, as were the athletic facilities. Renovation of the science facilities, which merged two buildings into the Olin-Rice Science Center, was completed in 1997. George Draper Dayton residence hall opened in 1998, the Ruth Stricker Dayton Campus Center in 2001, the renovated Kagin Commons student services building in 2002. A comprehensive fund-raising campaign completed in 2000 raised $55.3 million to help support some of those building projects as well as scholarship funds, student-faculty research stipends, academic programs, annual operations. Macalester’s Institute for Global Citizenship, created in 2005, serves as a catalyst for strengthening programs by which students connect academic study with off-campus applications through internships and service-learning opportunities both in the United States and abroad. In fall 2008 Macalester publicly launched a $150 million campaign, raising funds for scholarships, faculty support, program enhancement, operating support, new facilities.
In 2009, construction was completed on Markim Hall, a new home for the Institute for Global Citizenship. Plans called for the building to qualify for Platinum certification under the Leadership in Energy and Environmental Design system, a building rating system devised by the U. S. Green Building Council that evaluates the sustainability and environmental impact of structures across the nation. In fall 2012, Macalester opened its renovated and expanded Janet Wallace Fine Arts Center; the Macalester College Student Government constructed an ice rink on campus during the spring of 2013. The rink was a notable experiment in direct democracy, as students voted the previous year on how to spend a'rollover' of extra funds that were not allocated to student organizations. After a continued debate on whether funds should be returned to student groups, invested in campus infrastructure improvements, or used to fund textbooks, a plurality of the student body opted to build the ice rink. 50 students 2.5% of the student body volunteered to maintain the rink, but it fell into disrepair and was not supervised by the college's facilities department, who noted the'questionable flatness' of the ground under the rink.
After complaints that the rink was underused, the student government voted that year to permanently close the rink. In its 2016 edition, U. S. News & World Report ranked Macal