California Institute of Technology
The California Institute of Technology is a private doctorate-granting research university in Pasadena, California. Known for its strength in natural science and engineering, Caltech is ranked as one of the world's top-ten universities. Although founded as a preparatory and vocational school by Amos G. Throop in 1891, the college attracted influential scientists such as George Ellery Hale, Arthur Amos Noyes and Robert Andrews Millikan in the early 20th century; the vocational and preparatory schools were disbanded and spun off in 1910 and the college assumed its present name in 1921. In 1934, Caltech was elected to the Association of American Universities and the antecedents of NASA's Jet Propulsion Laboratory, which Caltech continues to manage and operate, were established between 1936 and 1943 under Theodore von Kármán; the university is one among a small group of institutes of technology in the United States, devoted to the instruction of pure and applied sciences. Caltech has six academic divisions with strong emphasis on science and engineering, managing $332 million in 2011 in sponsored research.
Its 124-acre primary campus is located 11 mi northeast of downtown Los Angeles. First-year students are required to live on campus and 95% of undergraduates remain in the on-campus House System at Caltech. Although Caltech has a strong tradition of practical jokes and pranks, student life is governed by an honor code which allows faculty to assign take-home examinations; the Caltech Beavers compete in 13 intercollegiate sports in the NCAA Division III's Southern California Intercollegiate Athletic Conference. As of October 2018, Caltech alumni and researchers include 73 Nobel Laureates, 4 Fields Medalists, 6 Turing Award winners. In addition, there are 53 non-emeritus faculty members who have been elected to one of the United States National Academies, 4 Chief Scientists of the U. S. Air Force and 71 have won the United States National Medal of Technology. Numerous faculty members are associated with the Howard Hughes Medical Institute as well as NASA. According to a 2015 Pomona College study, Caltech ranked number one in the U.
S. for the percentage of its graduates who go on to earn a PhD. Caltech started as a vocational school founded in Pasadena in 1891 by local businessman and politician Amos G. Throop; the school was known successively as Throop University, Throop Polytechnic Institute and Throop College of Technology before acquiring its current name in 1920. The vocational school was disbanded and the preparatory program was split off to form an independent Polytechnic School in 1907. At a time when scientific research in the United States was still in its infancy, George Ellery Hale, a solar astronomer from the University of Chicago, founded the Mount Wilson Observatory in 1904, he joined Throop's board of trustees in 1907, soon began developing it and the whole of Pasadena into a major scientific and cultural destination. He engineered the appointment of James A. B. Scherer, a literary scholar untutored in science but a capable administrator and fund raiser, to Throop's presidency in 1908. Scherer persuaded retired businessman and trustee Charles W. Gates to donate $25,000 in seed money to build Gates Laboratory, the first science building on campus.
In 1910, Throop moved to its current site. Arthur Fleming donated the land for the permanent campus site. Theodore Roosevelt delivered an address at Throop Institute on March 21, 1911, he declared: I want to see institutions like Throop turn out ninety-nine of every hundred students as men who are to do given pieces of industrial work better than any one else can do them. In the same year, a bill was introduced in the California Legislature calling for the establishment of a publicly funded "California Institute of Technology", with an initial budget of a million dollars, ten times the budget of Throop at the time; the board of trustees offered to turn Throop over to the state, but the presidents of Stanford University and the University of California lobbied to defeat the bill, which allowed Throop to develop as the only scientific research-oriented education institute in southern California, public or private, until the onset of the World War II necessitated the broader development of research-based science education.
The promise of Throop attracted physical chemist Arthur Amos Noyes from MIT to develop the institution and assist in establishing it as a center for science and technology. With the onset of World War I, Hale organized the National Research Council to coordinate and support scientific work on military problems. While he supported the idea of federal appropriations for science, he took exception to a federal bill that would have funded engineering research at land-grant colleges, instead sought to raise a $1 million national research fund from private sources. To that end, as Hale wrote in The New York Times: Throop College of Technology, in Pasadena California has afforded a striking illustration of one way in which the Research Council can secure co-operation and advance scientific investigation; this institution, with its able investigators and excellent research laboratories, could be of great service in any broad scheme of cooperation. President S
Solar System
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
France
France the French Republic, is a country whose territory consists of metropolitan France in Western Europe and several overseas regions and territories. The metropolitan area of France extends from the Mediterranean Sea to the English Channel and the North Sea, from the Rhine to the Atlantic Ocean, it is bordered by Belgium and Germany to the northeast and Italy to the east, Andorra and Spain to the south. The overseas territories include French Guiana in South America and several islands in the Atlantic and Indian oceans; the country's 18 integral regions span a combined area of 643,801 square kilometres and a total population of 67.3 million. France, a sovereign state, is a unitary semi-presidential republic with its capital in Paris, the country's largest city and main cultural and commercial centre. Other major urban areas include Lyon, Toulouse, Bordeaux and Nice. During the Iron Age, what is now metropolitan France was inhabited by a Celtic people. Rome annexed the area in 51 BC, holding it until the arrival of Germanic Franks in 476, who formed the Kingdom of Francia.
The Treaty of Verdun of 843 partitioned Francia into Middle Francia and West Francia. West Francia which became the Kingdom of France in 987 emerged as a major European power in the Late Middle Ages following its victory in the Hundred Years' War. During the Renaissance, French culture flourished and a global colonial empire was established, which by the 20th century would become the second largest in the world; the 16th century was dominated by religious civil wars between Protestants. France became Europe's dominant cultural and military power in the 17th century under Louis XIV. In the late 18th century, the French Revolution overthrew the absolute monarchy, established one of modern history's earliest republics, saw the drafting of the Declaration of the Rights of Man and of the Citizen, which expresses the nation's ideals to this day. In the 19th century, Napoleon established the First French Empire, his subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a tumultuous succession of governments culminating with the establishment of the French Third Republic in 1870.
France was a major participant in World War I, from which it emerged victorious, was one of the Allies in World War II, but came under occupation by the Axis powers in 1940. Following liberation in 1944, a Fourth Republic was established and dissolved in the course of the Algerian War; the Fifth Republic, led by Charles de Gaulle, remains today. Algeria and nearly all the other colonies became independent in the 1960s and retained close economic and military connections with France. France has long been a global centre of art and philosophy, it hosts the world's fourth-largest number of UNESCO World Heritage Sites and is the leading tourist destination, receiving around 83 million foreign visitors annually. France is a developed country with the world's sixth-largest economy by nominal GDP, tenth-largest by purchasing power parity. In terms of aggregate household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, human development.
France is considered a great power in global affairs, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a leading member state of the European Union and the Eurozone, a member of the Group of 7, North Atlantic Treaty Organization, Organisation for Economic Co-operation and Development, the World Trade Organization, La Francophonie. Applied to the whole Frankish Empire, the name "France" comes from the Latin "Francia", or "country of the Franks". Modern France is still named today "Francia" in Italian and Spanish, "Frankreich" in German and "Frankrijk" in Dutch, all of which have more or less the same historical meaning. There are various theories as to the origin of the name Frank. Following the precedents of Edward Gibbon and Jacob Grimm, the name of the Franks has been linked with the word frank in English, it has been suggested that the meaning of "free" was adopted because, after the conquest of Gaul, only Franks were free of taxation.
Another theory is that it is derived from the Proto-Germanic word frankon, which translates as javelin or lance as the throwing axe of the Franks was known as a francisca. However, it has been determined that these weapons were named because of their use by the Franks, not the other way around; the oldest traces of human life in what is now France date from 1.8 million years ago. Over the ensuing millennia, Humans were confronted by a harsh and variable climate, marked by several glacial eras. Early hominids led a nomadic hunter-gatherer life. France has a large number of decorated caves from the upper Palaeolithic era, including one of the most famous and best preserved, Lascaux. At the end of the last glacial period, the climate became milder. After strong demographic and agricultural development between the 4th and 3rd millennia, metallurgy appeared at the end of the 3rd millennium working gold and bronze, iron. France has numerous megalithic sites from the Neolithic period, including the exceptiona
Milky Way
The Milky Way is the galaxy that contains our Solar System. The name describes the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye; the term Milky Way is a translation of the Latin via lactea, from the Greek γαλαξίας κύκλος. From Earth, the Milky Way appears as a band. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610; until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies; the Milky Way is a barred spiral galaxy with a diameter between 200,000 light-years. It is estimated to contain 100 -- more than 100 billion planets; the Solar System is located at a radius of 26,490 light-years from the Galactic Center, on the inner edge of the Orion Arm, one of the spiral-shaped concentrations of gas and dust.
The stars in the innermost 10,000 light-years form a bulge and one or more bars that radiate from the bulge. The galactic center is an intense radio source known as Sagittarius A*, assumed to be a supermassive black hole of 4.100 million solar masses. Stars and gases at a wide range of distances from the Galactic Center orbit at 220 kilometers per second; the constant rotation speed contradicts the laws of Keplerian dynamics and suggests that much of the mass of the Milky Way is invisible to telescopes, neither emitting nor absorbing electromagnetic radiation. This conjectural mass has been termed "dark matter"; the rotational period is about 240 million years at the radius of the Sun. The Milky Way as a whole is moving at a velocity of 600 km per second with respect to extragalactic frames of reference; the oldest stars in the Milky Way are nearly as old as the Universe itself and thus formed shortly after the Dark Ages of the Big Bang. The Milky Way has several satellite galaxies and is part of the Local Group of galaxies, which form part of the Virgo Supercluster, itself a component of the Laniakea Supercluster.
The Milky Way is visible from Earth as a hazy band of white light, some 30° wide, arching across the night sky. In night sky observing, although all the individual naked-eye stars in the entire sky are part of the Milky Way, the term “Milky Way” is limited to this band of light; the light originates from the accumulation of unresolved stars and other material located in the direction of the galactic plane. Dark regions within the band, such as the Great Rift and the Coalsack, are areas where interstellar dust blocks light from distant stars; the area of sky that the Milky Way obscures is called the Zone of Avoidance. The Milky Way has a low surface brightness, its visibility can be reduced by background light, such as light pollution or moonlight. The sky needs to be darker than about 20.2 magnitude per square arcsecond in order for the Milky Way to be visible. It should be visible if the limiting magnitude is +5.1 or better and shows a great deal of detail at +6.1. This makes the Milky Way difficult to see from brightly lit urban or suburban areas, but prominent when viewed from rural areas when the Moon is below the horizon.
Maps of artificial night sky brightness show that more than one-third of Earth's population cannot see the Milky Way from their homes due to light pollution. As viewed from Earth, the visible region of the Milky Way's galactic plane occupies an area of the sky that includes 30 constellations; the Galactic Center lies in the direction of Sagittarius. From Sagittarius, the hazy band of white light appears to pass around to the galactic anticenter in Auriga; the band continues the rest of the way around the sky, back to Sagittarius, dividing the sky into two equal hemispheres. The galactic plane is inclined by about 60° to the ecliptic. Relative to the celestial equator, it passes as far north as the constellation of Cassiopeia and as far south as the constellation of Crux, indicating the high inclination of Earth's equatorial plane and the plane of the ecliptic, relative to the galactic plane; the north galactic pole is situated at right ascension 12h 49m, declination +27.4° near β Comae Berenices, the south galactic pole is near α Sculptoris.
Because of this high inclination, depending on the time of night and year, the arch of the Milky Way may appear low or high in the sky. For observers from latitudes 65° north to 65° south, the Milky Way passes directly overhead twice a day; the Milky Way is the second-largest galaxy in the Local Group, with its stellar disk 100,000 ly in diameter and, on average 1,000 ly thick. The Milky Way is 1.5 trillion times the mass of the Sun. To compare the relative physical scale of the Milky Way, if the Solar System out to Neptune were the size of a US quarter, the Milky Way would be the size of the contiguous United States. There is a ring-like filament of stars rippling above and below the flat galactic plane, wrapping around the Milky Way at a diameter of 150,000–180,000 light-years, which may be part of the Milky Way itself. Estimates of the mass of the Milky Way vary, depending upon the method and data used; the low end of the estimate range is 5.8×1011 solar masses, somewhat less than that of the Andromeda Galaxy.
Measurements using the Very Long Baseline Array in 2009 found
Unix
Unix is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, development starting in the 1970s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, others. Intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Microsoft, IBM, Sun Microsystems. In the early 1990s, AT&T sold its rights in Unix to Novell, which sold its Unix business to the Santa Cruz Operation in 1995; the UNIX trademark passed to The Open Group, a neutral industry consortium, which allows the use of the mark for certified operating systems that comply with the Single UNIX Specification. As of 2014, the Unix version with the largest installed base is Apple's macOS. Unix systems are characterized by a modular design, sometimes called the "Unix philosophy"; this concept entails that the operating system provides a set of simple tools that each performs a limited, well-defined function, with a unified filesystem as the main means of communication, a shell scripting and command language to combine the tools to perform complex workflows.
Unix distinguishes itself from its predecessors as the first portable operating system: the entire operating system is written in the C programming language, thus allowing Unix to reach numerous platforms. Unix was meant to be a convenient platform for programmers developing software to be run on it and on other systems, rather than for non-programmers; the system grew larger as the operating system started spreading in academic circles, as users added their own tools to the system and shared them with colleagues. At first, Unix was not designed to be multi-tasking. Unix gained portability, multi-tasking and multi-user capabilities in a time-sharing configuration. Unix systems are characterized by various concepts: the use of plain text for storing data; these concepts are collectively known as the "Unix philosophy". Brian Kernighan and Rob Pike summarize this in The Unix Programming Environment as "the idea that the power of a system comes more from the relationships among programs than from the programs themselves".
In an era when a standard computer consisted of a hard disk for storage and a data terminal for input and output, the Unix file model worked quite well, as I/O was linear. In the 1980s, non-blocking I/O and the set of inter-process communication mechanisms were augmented with Unix domain sockets, shared memory, message queues, semaphores, network sockets were added to support communication with other hosts; as graphical user interfaces developed, the file model proved inadequate to the task of handling asynchronous events such as those generated by a mouse. By the early 1980s, users began seeing Unix as a potential universal operating system, suitable for computers of all sizes; the Unix environment and the client–server program model were essential elements in the development of the Internet and the reshaping of computing as centered in networks rather than in individual computers. Both Unix and the C programming language were developed by AT&T and distributed to government and academic institutions, which led to both being ported to a wider variety of machine families than any other operating system.
Under Unix, the operating system consists of many libraries and utilities along with the master control program, the kernel. The kernel provides services to start and stop programs, handles the file system and other common "low-level" tasks that most programs share, schedules access to avoid conflicts when programs try to access the same resource or device simultaneously. To mediate such access, the kernel has special rights, reflected in the division between user space and kernel space - although in microkernel implementations, like MINIX or Redox, functions such as network protocols may run in user space; the origins of Unix date back to the mid-1960s when the Massachusetts Institute of Technology, Bell Labs, General Electric were developing Multics, a time-sharing operating system for the GE-645 mainframe computer. Multics featured several innovations, but presented severe problems. Frustrated by the size and complexity of Multics, but not by its goals, individual researchers at Bell Labs started withdrawing from the project.
The last to leave were Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna, who decided to reimplement their experiences in a new project of smaller scale. This new operating system was without organizational backing, without a name; the new operating system was a single-tasking system. In 1970, the group coined the name Unics for Uniplexed Information and Computing Service, as a pun on Multics, which stood for Multiplexed Information and Computer Services. Brian Kernighan takes credit for the idea, but adds that "no one can remember" the origin of the final spelling Unix. Dennis Ritchie, Doug McIlroy, Peter G. Neumann credit Kernighan; the operating system was written in assembly language, but in 1973, Version 4 Unix was rewritten in C. Version 4 Unix, still had many PDP-11 dependent codes, is not suitable for porting; the first port to other platform was made five years f
NASA Exoplanet Science Institute
The NASA Exoplanet Science Institute is part of the Infrared Processing and Analysis Center and is on the campus of the California Institute of Technology in Pasadena, CA. NExScI was known as the Michelson Science Center and before that as the Interferometry Science Center, it was renamed NExScI in the Fall of 2008 to reflect NASA's growing interest in the search for planets outside of our solar system known as exoplanets. The executive director of NExScI is Charles A. Beichman. NExScI is the science and analysis service organization for the NASA Exoplanet Exploration Program and the scientists and engineers that use them. NExScI facilitates the timely and successful execution of exoplanet science by providing software infrastructure, science operations, consulting to Exoplanet Exploration Program projects and their user communities; the activities and programs that NExScI oversees and manages are described in more detail in this article. The Sagan Program is administered for the Exoplanet Exploration Program by NExScI, it includes both the Sagan Fellowship Program and the Sagan Exoplanet Summer Workshop.
The Sagan Fellowships are one of three themed postdoctoral fellowships that are part of the Astrophysics Science Directorate. The Sagan Fellowships support Exoplanet research, are joined by two other NASA astrophysics theme-based fellowship programs: the Einstein Fellowship Program which supports Physics of the Cosmos research, the Hubble Fellowship Program which supports Cosmic Origins research. Applications to the Sagan Postdoctoral Program are accepted in the Fall of each year with 5-7 offers made by the following February; the fellowships are for three years with annual renewal contingent upon funding. Summer Workshops are part of the Sagan Exoplanet Program and offer a chance to graduate students and postdocs to explore an exoplanet-related topic in depth; the workshops have been offered since 1999. Recent topics of the summer workshops are Stars as Homes for Habitable Planets, Exoplanetary Atmospheres and Microlensing. NExScI maintains several astronomical data archives for use by the science community.
The two largest are the NASA Exoplanet Archive and the Keck Observatory Archive. Funded by NASA, the NASA Exoplanet Archive serves the user community working with exoplanet data by serving transit data sets from Kepler mission and COnvection ROtation and planetary Transits and providing long-term data curation and analysis tools; the archive content includes exoplanet and stellar host properties and Kepler candidate properties in interactive tables and time series data from space- and ground-based projects. Analysis tools include visualizations, periodogram calculations, transit ephemeris predictions; the new service is available at exoplanetarchive.ipac.caltech.edu. The Keck Observatory Archive is a NASA-funded collaboration between the NASA Exoplanet Science Institute and the W. M. Keck Observatory; the KOA archive includes data from two of the instruments on the Keck telescopes, the High Resolution Echelle Spectrograph and the Near InfraRed echelle SPECtrograph. KOA first released archived HIRES data on August 18, 2004 and the data extend back to 1994.
The NIRSPEC data were first released on May 17, 2010 and extend back to 1999. Public access to these data is governed by the data release policy agreed to between NASA and the Keck partner institutions. Observations supporting Deep Impact and GRB051111, a gamma ray burst observed on November 11, 2005, may be accessed from dedicated download pages, as well as through the KOA user interface; the two 10-meter aperture Keck telescopes are located on the dormant Mauna Kea volcano on the island of Hawaii. They are operated for the California Association for Research in Astronomy, the University of Hawaii, NASA by the William M. Keck Observatory in Waimea, HI; as a partner in the Keck telescopes, NASA receives 1/6th of the time available each year for astronomical observations. The proposal solicitation and scheduling is managed for NASA by NExScI, with calls for proposals issued twice each year for the two observing semesters on the telescopes. Proposals are evaluated on their scientific content as well as their tie to NASA's strategic and mission support goals.
The Keck Interferometer connects the two 10-meter Keck telescopes as an infrared interferometer with a baseline of 85 meters. This project was funded by NASA and developed by the Jet Propulsion Laboratory, the W. M. Keck Observatory and NExScI. KI included the visibility amplitude and nulling modes as well as a more developed astrometric mode. During KI operations, scientists at NExScI provided support to conduct observations. NExScI has developed various software tools to model and plan interferometric observations and to calibrate KI data. Following observing semester 2012A, the Keck Interferometer will no longer be available for use; however the data archive and software tools are still available and can be accessed through the NExScI's KI support page. The Large Binocular Telescope Interferometer is installed on the Large Binocular Telescope on Mt. Graham, Arizona. LBTI is designed to explore the regions surrounding nearby star systems for dust and planets and provide super resolution imaging in the mid-infrared.
LBTI science operations are expected to start in early 2013 and NExScI will provide the data archive for LBTI and serve as the support center for Guest Investigators using NASA time on the instrument. The Palomar Testbed Interferometer was a near-IR, long-baseline s
Astronomy
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
