Munich is the capital and most populous city of Bavaria, the second most populous German federal state. With a population of around 1.5 million, it is the third-largest city in Germany, after Berlin and Hamburg, as well as the 12th-largest city in the European Union. The city's metropolitan region is home to 6 million people. Straddling the banks of the River Isar north of the Bavarian Alps, it is the seat of the Bavarian administrative region of Upper Bavaria, while being the most densely populated municipality in Germany. Munich is the second-largest city in the Bavarian dialect area, after the Austrian capital of Vienna; the city is a global centre of art, technology, publishing, innovation, education and tourism and enjoys a high standard and quality of living, reaching first in Germany and third worldwide according to the 2018 Mercer survey, being rated the world's most liveable city by the Monocle's Quality of Life Survey 2018. According to the Globalization and World Rankings Research Institute Munich is considered an alpha-world city, as of 2015.
Munich is a major international center of engineering, science and research, exemplified by the presence of two research universities, a multitude of scientific institutions in the city and its surroundings, world class technology and science museums like the Deutsches Museum and BMW Museum.. Munich houses many multinational companies and its economy is based on high tech, the service sector and creative industries, as well as IT, biotechnology and electronics among many others; the name of the city is derived from the Old/Middle High German term Munichen, meaning "by the monks". It derives from the monks of the Benedictine order, who ran a monastery at the place, to become the Old Town of Munich. Munich was first mentioned in 1158. Catholic Munich resisted the Reformation and was a political point of divergence during the resulting Thirty Years' War, but remained physically untouched despite an occupation by the Protestant Swedes. Once Bavaria was established as a sovereign kingdom in 1806, it became a major European centre of arts, architecture and science.
In 1918, during the German Revolution, the ruling house of Wittelsbach, which had governed Bavaria since 1180, was forced to abdicate in Munich and a short-lived socialist republic was declared. In the 1920s, Munich became home to several political factions, among them the NSDAP; the first attempt of the Nazi movement to take over the German government in 1923 with the Beer Hall Putsch was stopped by the Bavarian police in Munich with gunfire. After the Nazis' rise to power, Munich was declared their "Capital of the Movement". During World War II, Munich was bombed and more than 50% of the entire city and up to 90% of the historic centre were destroyed. After the end of postwar American occupation in 1949, there was a great increase in population and economic power during the years of Wirtschaftswunder, or "economic miracle". Unlike many other German cities which were bombed, Munich restored most of its traditional cityscape and hosted the 1972 Summer Olympics; the 1980s brought strong economic growth, high-tech industries and scientific institutions, population growth.
The city is home to major corporations like BMW, Siemens, MAN, Linde and MunichRE. Munich is home to many universities and theatres, its numerous architectural attractions, sports events and its annual Oktoberfest attract considerable tourism. Munich is one of the fastest growing cities in Germany, it is a top-ranked destination for expatriate location. Munich hosts more than 530,000 people of foreign background; the first known settlement in the area was of Benedictine monks on the Salt road. The foundation date is not considered the year 1158, the date the city was first mentioned in a document; the document was signed in Augsburg. By the Guelph Henry the Lion, Duke of Saxony and Bavaria, had built a toll bridge over the river Isar next to the monk settlement and on the salt route, but as part of the archaeological excavations at Marienhof in advance of the expansion of the S-Bahn from 2012 shards of vessels from the eleventh century were found, which prove again that the settlement Munich must be older than their first documentary mention from 1158.
In 1175 Munich received city fortification. In 1180 with the trial of Henry the Lion, Otto I Wittelsbach became Duke of Bavaria, Munich was handed to the Bishop of Freising. In 1240, Munich was transferred to Otto II Wittelsbach and in 1255, when the Duchy of Bavaria was split in two, Munich became the ducal residence of Upper Bavaria. Duke Louis IV, a native of Munich, was elected German king in 1314 and crowned as Holy Roman Emperor in 1328, he strengthened the city's position by granting it the salt monopoly, thus assuring it of additional income. In the late 15th century, Munich underwent a revival of gothic arts: the Old Town Hall was enlarged, Munich's largest gothic church – the Frauenkirche – now a cathedral, was constructed in only 20 years, starting in 1468; when Bavaria was reunited in 1506, Munich became its capital. The arts and politics became influenced by the court. During the 16th century, Munich was a centre of the German counter reformation, of renaissance arts. Duke Wilhelm V commissioned the Jesuit Michaelskirche, which became a centre for the counter-reform
Kansas City, Missouri
Kansas City is the largest city in the U. S. state of Missouri. According to the U. S. Census Bureau, the city had an estimated population of 488,943 in 2017, making it the 37th most-populous city in the United States, it is the central city of the Kansas City metropolitan area, which straddles the Kansas–Missouri state line. Kansas City was founded in the 1830s as a Missouri River port at its confluence with the Kansas River coming in from the west. On June 1, 1850 the town of Kansas was incorporated. Confusion between the two ensued and the name Kansas City was assigned to distinguish them soon after. Sitting on Missouri's western boundary, with Downtown near the confluence of the Kansas and Missouri Rivers, the modern city encompasses some 319.03 square miles, making it the 23rd largest city by total area in the United States. Most of the city lies within Jackson County, but portions spill into Clay and Platte counties. Along with Independence, one of its major suburbs, it serves as one of the two county seats of Jackson County.
Other major suburbs include the Missouri cities of Blue Springs and Lee's Summit and the Kansas cities of Overland Park and Kansas City. The city is composed of several neighborhoods, including the River Market District in the north, the 18th and Vine District in the east, the Country Club Plaza in the south. Kansas City is known for its long tradition of jazz music and culture, for its cuisine, its craft breweries. Kansas City, Missouri was incorporated as a town on June 1, 1850, as a city on March 28, 1853; the territory straddling the border between Missouri and Kansas at the confluence of the Kansas and Missouri rivers was considered a good place to build settlements. The Antioch Christian Church, Dr. James Compton House, Woodneath are listed on the National Register of Historic Places; the first documented European visitor to Kansas City was Étienne de Veniard, Sieur de Bourgmont, the first European to explore the lower Missouri River. Criticized for his response to the Native American attack on Fort Détroit, he had deserted his post as fort commander and was avoiding French authorities.
Bourgmont lived with a Native American wife in a village about 90 miles east near Brunswick, where he illegally traded furs. To clear his name, he wrote Exact Description of Louisiana, of Its Harbors and Rivers, Names of the Indian Tribes That Occupy It, the Commerce and Advantages to Be Derived Therefrom for the Establishment of a Colony in 1713 followed in 1714 by The Route to Be Taken to Ascend the Missouri River. In the documents, he describes the junction of the "Grande Riv des Cansez" and Missouri River, making him the first to adopt those names. French cartographer Guillaume Delisle used the descriptions to make the area's first reasonably accurate map; the Spanish took over the region in the Treaty of Paris in 1763, but were not to play a major role other than taxing and licensing Missouri River ship traffic. The French continued their fur trade under Spanish license; the Chouteau family operated under Spanish license at St. Louis in the lower Missouri Valley as early as 1765 and in 1821 the Chouteaus reached Kansas City, where François Chouteau established Chouteau's Landing.
After the 1804 Louisiana Purchase and Clark visited the confluence of the Kansas and Missouri rivers, noting it was a good place to build a fort. In 1831, a group of Mormons from New York settled in, they built the first school within Kansas City's current boundaries, but were forced out by mob violence in 1833 and their settlement remained vacant. In 1833 John McCoy, son of missionary Isaac McCoy, established West Port along the Santa Fe Trail, 3 miles away from the river. In 1834 McCoy established Westport Landing on a bend in the Missouri to serve as a landing point for West Port. Soon after, the Kansas Town Company, a group of investors, began to settle the area, taking their name from an English spelling of "Cansez." In 1850, the landing area was incorporated as the Town of Kansas. By that time, the Town of Kansas and nearby Independence, had become critical points in the United States' westward expansion. Three major trails – the Santa Fe, Oregon – all passed through Jackson County. On February 22, 1853, the City of Kansas was created with a newly elected mayor.
It had an area of 0.70 square miles and a population of 2,500. The boundary lines at that time extended from the middle of the Missouri River south to what is now Ninth Street, from Bluff Street on the west to a point between Holmes Road and Charlotte Street on the east; the Kansas City area was rife with animosity just prior to the U. S. Civil War. Kansas petitioned the U. S. to enter the Union as a free state that did not allow slavery under the new doctrine of popular sovereignty. Missouri had many slaves, slavery sympathizers crossed into Kansas to sway the state towards allowing slavery, at first by ballot box and by bloodshed. During the Civil War, the city and its immediate surroundings were the focus of intense military activity. Although the First Battle of Independence in August 1862 resulted in a Confederate States Army victory, the Confederates were unable to leverage their win in any significant fashion, as Kansas City was occupied by Union troops and proved too fortified to assault.
The Second Battle of Independence, which occurred on October 21–22, 1864 as part of Sterling Price's Missouri expedition of 1864 resulted in a Confederate triumph. Once again their victory proved hollow, as Price was decisively defeated in the pivotal Battle of Westport the next day ending Confederate e
The Deutsches Museum in Munich, Germany, is the world's largest museum of science and technology, with about 28,000 exhibited objects from 50 fields of science and technology. It receives about 1.5 million visitors per year. The museum was founded on 28 June 1903, at a meeting of the Association of German Engineers as an initiative of Oskar von Miller, it is the largest museum in Munich. For a period of time the museum was used to host pop and rock concerts including The Who, Jimi Hendrix and Elton John; the main site of the Deutsches Museum is a small island in the Isar river, used for rafting wood since the Middle Ages. The island did not have any buildings before 1772 because it was flooded prior to the building of the Sylvensteinspeicher. In 1772 the Isar barracks were built on the island and, after the flooding of 1899, the buildings were rebuilt with flood protection. In 1903 the city council announced that they would donate the island for the newly built Deutsches Museum; the island known as Kohleninsel was renamed Museumsinsel.
In addition to the main site on the Museumsinsel, the museum has two branches in and near Munich and one in Bonn. The Flugwerft Schleißheim branch is located some 18 kilometres north of Munich's city centre close to Schleißheim Palace, it is based on the premises of one of the first military airbases in Germany founded just before World War I. It comprises the old air control and command centre as well as modern buildings added in the late 2000s after strong endorsement from Franz-Josef Strauss, the prime minister of the state of Bavaria, a passionate flyer; the Flugwerft Schleißheim displays various interesting airplanes for which there was insufficient room at the Museumsinsel site in downtown Munich. Among the more prominent exhibits is a Horten flying wing glider built in the 1940s, restored from the few surviving parts. A collection of the German constructions of VTOL planes developed in the 1950s and 1960s is unique. A range of Vietnam era fighter planes as well as Russian planes taken over from East Germany after the reunification are on display.
This outstation features a workshop dedicated to the restoration of all types of airplanes intended for static display. The latest branch opened in 2003 and is called the Deutsches Museum Verkehrszentrum, located at Theresienhöhe in Munich, focuses on transportation technology; the branch located in Bonn was opened in 1995 and focuses on German technology and research after 1945. Oskar von Miller studied electrical engineering and is otherwise known for building the first high voltage line from Miesbach to Munich in 1882 for the electrical technology exhibition at the Glaspalast in Munich. In 1883 he founded an engineering office in Munich; the Frankfurt electricity exhibition in 1891 and several power plants contributed to the reputation of Oskar von Miller. In the early years, the exhibition and the collection of the Deutsches Museum were influenced by Oskar von Miller. A few months before the 1903 meeting of the Society of German Engineers, Oskar von Miller gathered a small group who supported his desire to found a science and technology museum.
In a showing of support this group spontaneously donated 260,000 marks to the cause and elected a "Provisional Committee" to get the ball rolling. In June 1903, Prince Ludwig agreed to act as patron of the museum and the city of Munich donated Coal Island as a site for the project. In addition, exhibits began to arrive from Munich and abroad including collections from the Bavarian Academy; as no dedicated museum building existed, the exhibits were displayed in the National Museum. On 12 November 1906, the temporary exhibits at the National Museum were ceremonially opened to the public and on November 13 the foundation stone was laid for the permanent museum; the first name of the museum, the "German Museum for Masterpieces of Natural Science and Technology", was not meant to limit the museum to German advances in science and technology, but to express the importance of science and technology to the German people. Oskar von Miller opened the new museum on his 70th birthday, 2 May 1925, after a delay of ten years.
From the beginning, the museum displays are backed up by documents available in a public library and archives, which are open seven days a week to ensure access to the working public. Before and during World War II the museum was put on a shoestring budget by the Nazi party and many exhibits were allowed to get out of date with a few exceptions such as the new automobile room dedicated 7 May 1937. By the end of 1944 the museum was badly damaged by air bombings with 80% of the buildings and 20% of the exhibits damaged or destroyed; as Allied troops marched into Munich in April 1945, museum director, Karl Bässler managed to keep the last standing bridge to Museum Island from being blown up by retreating German troops. Following the war the museum had to be closed for repairs and temporary tenants, such as the College of Technology and the Post Office used museum space as their own buildings were being reconstructed; the Museum was home to the Central Committee of the Liberated Jews, representing Jewish displaced persons in the American Zone of Germany after the war.
In November 1945, the library was able to reopen, followed by the congress hall in January 1946. A special exhibit on fifty years of the Diesel engine opened in October 1947 and the regular exhibits began reopening in May 1948. Not until 1965, more than twenty years after the end of the war in Germany, did the exhibit area match (and e
Integrated Authority File
The Integrated Authority File or GND is an international authority file for the organisation of personal names, subject headings and corporate bodies from catalogues. It is used for documentation in libraries and also by archives and museums; the GND is managed by the German National Library in cooperation with various regional library networks in German-speaking Europe and other partners. The GND falls under the Creative Commons Zero licence; the GND specification provides a hierarchy of high-level entities and sub-classes, useful in library classification, an approach to unambiguous identification of single elements. It comprises an ontology intended for knowledge representation in the semantic web, available in the RDF format; the Integrated Authority File became operational in April 2012 and integrates the content of the following authority files, which have since been discontinued: Name Authority File Corporate Bodies Authority File Subject Headings Authority File Uniform Title File of the Deutsches Musikarchiv At the time of its introduction on 5 April 2012, the GND held 9,493,860 files, including 2,650,000 personalised names.
There are seven main types of GND entities: LIBRIS Virtual International Authority File Information pages about the GND from the German National Library Search via OGND Bereitstellung des ersten GND-Grundbestandes DNB, 19 April 2012 From Authority Control to Linked Authority Data Presentation given by Reinhold Heuvelmann to the ALA MARC Formats Interest Group, June 2012
Wrocław is a city in western Poland and the largest city in the historical region of Silesia. It lies on the banks of the River Oder in the Silesian Lowlands of Central Europe 350 kilometres from the Baltic Sea to the north and 40 kilometres from the Sudeten Mountains to the south; the population of Wrocław in 2018 was 639,258, making it the fourth-largest city in Poland and the main city of the Wrocław agglomeration. Wrocław is the historical capital of Lower Silesia. Today, it is the capital of the Lower Silesian Voivodeship; the history of the city dates back over a thousand years, its extensive heritage combines all religions and cultures of Europe. At various times, it has been part of the Kingdom of Poland, Kingdom of Bohemia, Kingdom of Hungary, Habsburg Monarchy and Germany. Wrocław became part of Poland again in 1945, as a result of the border changes after the Second World War, which included a nearly complete exchange of population. Wrocław is a university city with a student population of over 130,000, making it one of the most youthful cities in the country.
Since the beginning of the 20th century, the University of Wrocław Breslau University, produced 9 Nobel Prize laureates and is renowned for its high quality of teaching. Wrocław is classified as a Gamma-global city by GaWC, it was placed among the top 100 cities in the world for the quality of life by the consulting company Mercer and in the top 100 of the smartest cities in the world in the IESE Cities in Motion Index 2017 report. The city hosted the Eucharistic Congress in the Euro 2012 football championships. In 2016, the city was a European Capital of the World Book Capital. In this year, Wrocław hosted the Theatre Olympics, World Bridge Games and the European Film Awards. In 2017, the city was the host of the World Games; the city's name was first recorded as "Wrotizlava" in the chronicle of German chronicler Thietmar of Merseburg, which mentions it as a seat of a newly installed bishopric in the context of the Congress of Gniezno. The first municipal seal stated. A simplified name is given, as Wrezlaw, Prezla or Breslaw.
The Czech spelling was used in Latin documents as Vratislavia. At that time, Prezla was used in Middle High German. In the middle of the 14th century, the Early New High German form of the name, began to replace its earlier versions; the city is traditionally believed to be named after Wrocisław or Vratislav believed to be named after Duke Vratislaus I of Bohemia. It is possible that the city was named after the tribal duke of the Silesians or after an early ruler of the city called Vratislav; the city's name in various other languages is: Hungarian: Boroszló, Czech: Vratislav, German: Breslau, Hebrew: ורוצלב, Yiddish: ברעסלוי, Silesian German: Brassel, Latin: Vratislavia or Budorgis or Wratislavia. The city's name in other languages is available at the list of names of European cities. Persons born or living in the city are known as "Vratislavians". In ancient times at or near Wrocław was a place called Budorigum, it has been mapped to Claudius Ptolemy's map of AD 142–147. The city of Wrocław originated at the intersection of two trade routes, the Via Regia and the Amber Road.
Settlements in the area existed during the migration period. A Slavic tribe Ślężans erected on Ostrów Tumski a gord; the city was first recorded in the 10th century as Vratislavia, the Bohemian duke Vratislaus I founded here a Bohemian stronghold. Vratislavia was derived from the duke's name Vratislav. In 985, Duke Mieszko I of Poland conquered Silesia including Wrocław; the town was mentioned explicitly in the year 1000 AD in connection with a founding of a bishopric during the Congress of Gniezno. The medieval chronicle, Gesta principum Polonorum, written by Gallus Anonymus in 1112–1116, named Wrocław, along with Kraków and Sandomierz, as one of the three capitals of the Polish Kingdom. During Wrocław's early history, the control over it changed hands between Bohemia, the Kingdom of Poland, after the fragmentation of the Kingdom of Poland, the Piast-ruled duchy of Silesia. One of the most important events during this period was the foundation of the Diocese of Wrocław by the Polish Duke Bolesław the Brave in 1000.
Along with the Bishoprics of Kraków and Kołobrzeg, Wrocław was placed under the Archbishopric of Gniezno in Greater Poland, founded by Pope Sylvester II through the intercession of the Emperor Otto III in 1000, during the Congress of Gniezno. In the years 1034–1038 the city was affected by Pagan reaction in Poland; the city became a commercial centre and expanded to Wyspa Piasek, to the left bank of the River Oder. Around 1000, the town had about 1,000 inhabitants. In 1109 during the Polish-German war, Prince Bolesław III Wrymouth defeated the King of Germany Henry V at the Battle of Hundsfeld, stopping the German march into Poland. By 1139, a settlement belonging to Governor Piotr Włostowic was built, another was founded on the left bank of the River Oder, near the present seat of the University. While the city was Polish, there were communities of Bohemians, Jews and Germans. In the 13th century, Wrocław was the political centre of the divided Polish kingdom. In April 1241, during the First Mongol invasion of Poland the city was abandoned by the inhabitants and burned for strategic reason
A patent is a form of intellectual property. A patent gives its owner the right to exclude others from making, using and importing an invention for a limited period of time twenty years; the patent rights are granted in exchange for an enabling public disclosure of the invention. In most countries patent rights fall under civil law and the patent holder needs to sue someone infringing the patent in order to enforce his or her rights. In some industries patents are an essential form of competitive advantage; the procedure for granting patents, requirements placed on the patentee, the extent of the exclusive rights vary between countries according to national laws and international agreements. However, a granted patent application must include one or more claims that define the invention. A patent may include many claims; these claims must meet relevant patentability requirements, such as novelty and non-obviousness. Under the World Trade Organization's TRIPS Agreement, patents should be available in WTO member states for any invention, in all fields of technology, provided they are new, involve an inventive step, are capable of industrial application.
There are variations on what is patentable subject matter from country to country among WTO member states. TRIPS provides that the term of protection available should be a minimum of twenty years; the word patent originates from the Latin patere, which means "to lay open". It is a shortened version of the term letters patent, an open document or instrument issued by a monarch or government granting exclusive rights to a person, predating the modern patent system. Similar grants included land patents, which were land grants by early state governments in the USA, printing patents, a precursor of modern copyright. In modern usage, the term patent refers to the right granted to anyone who invents something new and non-obvious; some other types of intellectual property rights are called patents in some jurisdictions: industrial design rights are called design patents in the US, plant breeders' rights are sometimes called plant patents, utility models and Gebrauchsmuster are sometimes called petty patents or innovation patents.
The additional qualification utility patent is sometimes used to distinguish the primary meaning from these other types of patents. Particular species of patents for inventions include biological patents, business method patents, chemical patents and software patents. Although there is some evidence that some form of patent rights was recognized in Ancient Greece in the Greek city of Sybaris, the first statutory patent system is regarded to be the Venetian Patent Statute of 1474. Patents were systematically granted in Venice as of 1474, where they issued a decree by which new and inventive devices had to be communicated to the Republic in order to obtain legal protection against potential infringers; the period of protection was 10 years.. As Venetians emigrated, they sought similar patent protection in their new homes; this led to the diffusion of patent systems to other countries. The English patent system evolved from its early medieval origins into the first modern patent system that recognised intellectual property in order to stimulate invention.
By the 16th century, the English Crown would habitually abuse the granting of letters patent for monopolies. After public outcry, King James I of England was forced to revoke all existing monopolies and declare that they were only to be used for "projects of new invention"; this was incorporated into the Statute of Monopolies in which Parliament restricted the Crown's power explicitly so that the King could only issue letters patent to the inventors or introducers of original inventions for a fixed number of years. The Statute became the foundation for developments in patent law in England and elsewhere. Important developments in patent law emerged during the 18th century through a slow process of judicial interpretation of the law. During the reign of Queen Anne, patent applications were required to supply a complete specification of the principles of operation of the invention for public access. Legal battles around the 1796 patent taken out by James Watt for his steam engine, established the principles that patents could be issued for improvements of an existing machine and that ideas or principles without specific practical application could legally be patented.
Influenced by the philosophy of John Locke, the granting of patents began to be viewed as a form of intellectual property right, rather than the obtaining of economic privilege. The English legal system became the foundation for patent law in countries with a common law heritage, including the United States, New Zealand and Australia. In the Thirteen Colonies, inventors could obtain patents through petition to a given colony's legislature. In 1641, Samuel Winslow was granted the first patent in North America by the Massachusetts General Court for a new process for making salt; the modern French patent system was created during the Revolution in 1791. Patents were granted without examination. Patent costs were high. Importation patents protected new devices coming from foreign countries; the patent law was revised in 1844 - patent cost was lowered and importation patents were abolished. The first Patent Act of the U. S. Congress was passed on April 10, 1790, titled "An Act to promote the progress of
An optical fiber is a flexible, transparent fiber made by drawing glass or plastic to a diameter thicker than that of a human hair. Optical fibers are used most as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths than electrical cables. Fibers are used instead of metal wires. Fibers are used for illumination and imaging, are wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are used for a variety of other applications, some of them being fiber optic sensors and fiber lasers. Optical fibers include a core surrounded by a transparent cladding material with a lower index of refraction. Light is kept in the core by the phenomenon of total internal reflection which causes the fiber to act as a waveguide. Fibers that support many propagation paths or transverse modes are called multi-mode fibers, while those that support a single mode are called single-mode fibers.
Multi-mode fibers have a wider core diameter and are used for short-distance communication links and for applications where high power must be transmitted. Single-mode fibers are used for most communication links longer than 1,000 meters. Being able to join optical fibers with low loss is important in fiber optic communication; this is more complex than joining electrical wire or cable and involves careful cleaving of the fibers, precise alignment of the fiber cores, the coupling of these aligned cores. For applications that demand a permanent connection a fusion splice is common. In this technique, an electric arc is used to melt the ends of the fibers together. Another common technique is a mechanical splice, where the ends of the fibers are held in contact by mechanical force. Temporary or semi-permanent connections are made by means of specialized optical fiber connectors; the field of applied science and engineering concerned with the design and application of optical fibers is known as fiber optics.
The term was coined by Indian physicist Narinder Singh Kapany, acknowledged as the father of fiber optics. Guiding of light by refraction, the principle that makes fiber optics possible, was first demonstrated by Daniel Colladon and Jacques Babinet in Paris in the early 1840s. John Tyndall included a demonstration of it in his public lectures in London, 12 years later. Tyndall wrote about the property of total internal reflection in an introductory book about the nature of light in 1870:When the light passes from air into water, the refracted ray is bent towards the perpendicular... When the ray passes from water to air it is bent from the perpendicular... If the angle which the ray in water encloses with the perpendicular to the surface be greater than 48 degrees, the ray will not quit the water at all: it will be reflected at the surface.... The angle which marks the limit where total reflection begins is called the limiting angle of the medium. For water this angle is 48°27′, for flint glass it is 38°41′, while for diamond it is 23°42′.
In the late 19th and early 20th centuries, light was guided through bent glass rods to illuminate body cavities. Practical applications such as close internal illumination during dentistry appeared early in the twentieth century. Image transmission through tubes was demonstrated independently by the radio experimenter Clarence Hansell and the television pioneer John Logie Baird in the 1920s. In the 1930s, Heinrich Lamm showed that one could transmit images through a bundle of unclad optical fibers and used it for internal medical examinations, but his work was forgotten. In 1953, Dutch scientist Bram van Heel first demonstrated image transmission through bundles of optical fibers with a transparent cladding; that same year, Harold Hopkins and Narinder Singh Kapany at Imperial College in London succeeded in making image-transmitting bundles with over 10,000 fibers, subsequently achieved image transmission through a 75 cm long bundle which combined several thousand fibers. Their article titled "A flexible fibrescope, using static scanning" was published in the journal Nature in 1954.
The first practical fiber optic semi-flexible gastroscope was patented by Basil Hirschowitz, C. Wilbur Peters, Lawrence E. Curtiss, researchers at the University of Michigan, in 1956. In the process of developing the gastroscope, Curtiss produced the first glass-clad fibers. A variety of other image transmission applications soon followed. Kapany coined the term fiber optics, wrote a 1960 article in Scientific American that introduced the topic to a wide audience, wrote the first book about the new field; the first working fiber-optical data transmission system was demonstrated by German physicist Manfred Börner at Telefunken Research Labs in Ulm in 1965, followed by the first patent application for this technology in 1966. NASA used fiber optics in the television cameras. At the time, the use in the cameras was classified confidential, employees handling the cameras had to be supervised by someone with an appropriate security clearance. Charles K. Kao and George A. Hockham of the British company Standard Telephones and Cables were the first, in 1965, to promote the idea that the attenuation in optical fibers could be reduced below 20 decibels per kilometer, making fibers a practical communication medium.
They proposed th