|
Geographical Mile
The geographical mile is a unit of length determined by 1 minute of arc along the Earth's equator. For the international ellipsoid 1924 this equalled 1855.4 metres. ''The American Practical Navigator'' 2017 defines the geographical mile as . Greater precision depends more on choice of ellipsoid than on more careful measurement: the length of the equator in the World Geodetic System WGS-84 is , which makes the geographical mile 1855.3248 m,. Equatorial radius = 6,378,137 m. while the '' IERS Conventions (2010)'' takes the equator to be , making the geographical mile 1855.3247 m,. Equatorial radius = 6,378,136.6 m. 0.1 millimetres shorter. In any ellipsoid, the length of a degree of longitude at the equator is thus exactly 60 geographical miles. The shape of the Earth is a slightly flattened sphere, which results in the Earth's circumference being 0.168% larger when measured around the equator as compared to through the poles. The geographical mile is slightly larger than the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SI Units
The International System of Units, known by the international abbreviation SI in all languages and sometimes Pleonasm#Acronyms and initialisms, pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. Established and maintained by the General Conference on Weights and Measures (CGPM), it is the only system of measurement with an official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce. The SI comprises a Coherence (units of measurement), coherent system of units of measurement starting with seven SI base unit, base units, which are the second (symbol s, the unit of time), metre (m, length), kilogram (kg, mass), ampere (A, electric current), kelvin (K, thermodynamic temperature), Mole (unit), mole (mol, amount of substance), and candela (cd, luminous intensity). The system can accommodate coherent units for an unlimited number of additional qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Circle
In mathematics, a great circle or orthodrome is the circular intersection of a sphere and a plane passing through the sphere's center point. Any arc of a great circle is a geodesic of the sphere, so that great circles in spherical geometry are the natural analog of straight lines in Euclidean space. For any pair of distinct non- antipodal points on the sphere, there is a unique great circle passing through both. (Every great circle through any point also passes through its antipodal point, so there are infinitely many great circles through two antipodal points.) The shorter of the two great-circle arcs between two distinct points on the sphere is called the ''minor arc'', and is the shortest surface-path between them. Its arc length is the great-circle distance between the points (the intrinsic distance on a sphere), and is proportional to the measure of the central angle formed by the two points and the center of the sphere. A great circle is the largest circle that c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mile
The mile, sometimes the international mile or statute mile to distinguish it from other miles, is a British imperial unit and United States customary unit of distance; both are based on the older English unit of length equal to 5,280 English feet, or 1,760 yards. The statute mile was standardised between the British Commonwealth and the United States by an international agreement in 1959, when it was formally redefined with respect to SI units as exactly . With qualifiers, ''mile'' is also used to describe or translate a wide range of units derived from or roughly equivalent to the Roman mile, such as the nautical mile (now exactly), the Italian mile (roughly ), and the Chinese mile (now exactly). The Romans divided their mile into 5,000 Roman feet but the greater importance of furlongs in Elizabethan-era England meant that the statute mile was made equivalent to or in 1593. This form of the mile then spread across the British Empire, some successor states of which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medieval Weights And Measures
The following systems arose from earlier systems, and in many cases utilise parts of much older systems. For the most part they were used to varying degrees in the Middle Ages and surrounding time periods. Some of these systems found their way into later systems, such as the Imperial system and even SI. English system Before Roman units were reintroduced in 1066 by William the Conqueror, there was an Anglo-Saxon (Germanic) system of measure, of which few details survive. It probably included the following units of length: * ''fingerbreadth'' or ''digit'' * ''inch'' * ''ell'' or ''cubit'' * ''foot'' * ''perch'', used variously to measure length or area * ''acre'' and ''acre's breadth'' * ''furlong'' * ''mile'' The best-attested of these is the ''perch'', which varied in length from 10 to 25 feet, with the most common value (16 feet or 5.03 m) remaining in use until the twentieth century. Later development of the English system continued in 1215 in the Magna Carta. Standards w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conversion Of Units
Conversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors which change the measured quantity value without changing its effects. Overview The process of conversion depends on the specific situation and the intended purpose. This may be governed by regulation, contract, technical specifications or other published standards. Engineering judgment may include such factors as: * The precision and accuracy of measurement and the associated uncertainty of measurement. * The statistical confidence interval or tolerance interval of the initial measurement. * The number of significant figures of the measurement. * The intended use of the measurement including the engineering tolerances. * Historical definitions of the units and their derivatives used in old measurements; e.g., international foot vs. US survey foot. Some conversions from one system of units to another need to be exact, without ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denmark
) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Danish Realm, Kingdom of Denmark , established_title = History of Denmark#Middle ages, Consolidation , established_date = 8th century , established_title2 = Christianization , established_date2 = 965 , established_title3 = , established_date3 = 5 June 1849 , established_title4 = Faroese home rule , established_date4 = 24 March 1948 , established_title5 = European Economic Community, EEC 1973 enlargement of the European Communities, accession , established_date5 = 1 January 1973 , established_title6 = Greenlandic home rule , established_date6 = 1 May 1979 , official_languages = Danish language, Danish , languages_type = Regional languages , languages_sub = yes , languages = German language, GermanGerman is recognised as a protected minority language in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ole Rømer
Ole Christensen Rømer (; 25 September 1644 – 19 September 1710) was a Danish astronomer who, in 1676, made the first measurement of the speed of light. Rømer also invented the modern thermometer showing the temperature between two fixed points, namely the points at which water respectively boils and freezes. In scientific literature, alternative spellings such as "Roemer", "Römer", or "Romer" are common. Biography Rømer was born on 25 September 1644 in Århus to merchant and skipper Christen Pedersen (died 1663), and Anna Olufsdatter Storm ( – 1690), daughter of a well-to-do alderman. Since 1642, Christen Pedersen had taken to using the name Rømer, which means that he was from the Danish island of Rømø, to distinguish himself from a couple of other people named Christen Pedersen. There are few records of Ole Rømer before 1662, when he graduated from the old Aarhus Katedralskole (the Cathedral school of Aarhus), moved to Copenhagen and matriculated at the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Library Of Congress
The Library of Congress (LOC) is the research library that officially serves the United States Congress and is the ''de facto'' national library of the United States. It is the oldest federal cultural institution in the country. The library is housed in three buildings on Capitol Hill in Washington, D.C.; it also maintains a conservation center in Culpeper, Virginia. The library's functions are overseen by the Librarian of Congress, and its buildings are maintained by the Architect of the Capitol. The Library of Congress is one of the largest libraries in the world. Its "collections are universal, not limited by subject, format, or national boundary, and include research materials from all parts of the world and in more than 470 languages." Congress moved to Washington, D.C., in 1800 after holding sessions for eleven years in the temporary national capitals in New York City and Philadelphia. In both cities, members of the U.S. Congress had access to the sizable collection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hundred (county Subdivision)
A hundred is an administrative division that is geographically part of a larger region. It was formerly used in England, Wales, some parts of the United States, Denmark, Southern Schleswig, Sweden, Finland, Norway, the Bishopric of Ösel–Wiek, Curonia, the Ukrainian state of the Cossack Hetmanate and in Cumberland County, New South Wales, Cumberland County in the British Colony of New South Wales. It is still used in other places, including in Australia (in South Australia and the Northern Territory). Other terms for the hundred in English and other languages include ''#wapentake, wapentake'', ''herred'' (Danish and Bokmål, Bokmål Norwegian), ''herad'' (Nynorsk, Nynorsk Norwegian), ''hérað'' (Icelandic), ''härad'' or ''hundare'' (Swedish), ''Harde'' (German), ''hiird'' (North Frisian language, North Frisian), ''satakunta'' or ''kihlakunta'' (Finnish), ''kihelkond'' (Estonian), ''kiligunda'' (Livonian), ''cantref'' (Welsh) and ''sotnia'' (Slavic). In Ireland, a similar subdi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Jefferson
Thomas Jefferson (April 13, 1743 – July 4, 1826) was an American statesman, diplomat, lawyer, architect, philosopher, and Founding Fathers of the United States, Founding Father who served as the third president of the United States from 1801 to 1809. He was previously the nation's second vice president of the United States, vice president under John Adams and the first United States Secretary of State, United States secretary of state under George Washington. The principal author of the United States Declaration of Independence, Declaration of Independence, Jefferson was a proponent of democracy, republicanism, and individual rights, motivating Thirteen Colonies, American colonists to break from the Kingdom of Great Britain and form a new nation. He produced formative documents and decisions at state, national, and international levels. During the American Revolution, Jefferson represented Virginia in the Continental Congress that adopted the Declaration of Independence. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Ordinance Of 1785
The Land Ordinance of 1785 was adopted by the United States Congress of the Confederation on May 20, 1785. It set up a standardized system whereby settlers could purchase title to farmland in the undeveloped west. Congress at the time did not have the power to raise revenue by direct taxation, so land sales provided an important revenue stream. The Ordinance set up a survey system that eventually covered over three-quarters of the area of the continental United States. The earlier Land Ordinance of 1784 was a resolution written by Thomas Jefferson calling for Congress to take action. The land west of the Appalachian Mountains, north of the Ohio River and east of the Mississippi River was to be divided into ten separate states. However, the 1784 resolution did not define the mechanism by which the land would become states, or how the territories would be governed or settled before they became states. The Ordinance of 1785 put the 1784 resolution in operation by providing a mechanis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> SI Units")
.jpg "Click for more on -> Hundred (county Subdivision)")
