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International System Of Units The INTERNATIONAL SYSTEM OF UNITS (abbreviated as SI, from the French _Système internationale (d'unités)_) is the modern form of the metric system , and is the most widely used system of measurement . It comprises a coherent system of units of measurement built on seven base units . The system also establishes a set of twenty prefixes to the unit names and unit symbols that may be used when specifying multiples and fractions of the units. The system was published in 1960 as a result of an initiative that began in 1948. It is based on the metre–kilogram–second system of units (MKS) rather than any variant of the centimetre–gram–second system (CGS). SI is intended to be an evolving system, so prefixes and units are created and unit definitions are modified through international agreement as the technology of measurement progresses and the precision of measurements improves. The 24th and 25th General Conferences on Weights and Measures (CGPM) in 2011 and 2014, for example, discussed a proposal to change the definition of the kilogram , linking it to an invariant of nature rather than to the mass of a material artefact, thereby ensuring longterm stability. The motivation for the development of the SI was the diversity of units that had sprung up within the CGS systems and the lack of coordination between the various disciplines that used them [...More...]  "International System Of Units" on: Wikipedia Yahoo 

SI (other) SI, SI or SI may refer to: CONTENTS* 1 Arts and media * 1.1 Music * 1.2 Publications * 2 Organisations * 2.1 Education * 2.2 Government * 2.3 Computing * 2.4 Politics * 3 Places * 4 Science and technology * 4.1 Biology and medicine * 4.2 Computing and Internet * 4.3 Vehicles * 5 Titles and ranks * 6 Other uses * 7 See also ARTS AND MEDIA * Si (film) , original title of the 2010 South Korean film Poetry * Si, a selfreplicating artifact in the computer game Ancient Domains of Mystery MUSIC * Si (musical note) , the seventh note in the traditional fixed do solfège * "Sì" (song) , the name of the Italian entry to the Eurovision Song Contest 1974 * "Sì", a 1985 song released by Italian actress Carmen Russo Carmen Russo [...More...]  "SI (other)" on: Wikipedia Yahoo 

Outline Of The Metric System The following outline is provided as an overview of and topical guide to the metric system: METRIC SYSTEM – various loosely related systems of measurement that trace their origin to the decimal system of measurement introduced in France during the French Revolution . CONTENTS* 1 Nature of the metric system * 1.1 Essence of the metric system * 1.2 Underlying philosophy * 2 Metric units of measure * 3 History of the metric system * 3.1 Chronological history of the metric system * 3.2 History of metrication * 3.3 Historical metric system variants * 3.4 History of metric units * 4 Politics of the metric system * 5 Future of the metric system * 6 Metric system organizations * 7 Metric system publications * 8 Persons influential in the metric system * 9 See also * 10 References * 11 External links NATURE OF THE METRIC SYSTEMThe metric system can be described as all of the following: * System – set of interacting or interdependent components forming an integrated whole. * System of measurement – set of units which can be used to specify anything which can be measured. Historically, systems of measurement were initially defined and regulated to support trade and internal commerce. Units were arbitrarily defined by fiat (see statutory law) by the ruling entities and were not necessarily well interrelated or selfconsistent [...More...]  "Outline Of The Metric System" on: Wikipedia Yahoo 

Metric System The METRIC SYSTEM is an internationally agreed decimal system of measurement . It was originally based on the _mètre des Archives _ and the _kilogramme des Archives _ introduced by the French First Republic in 1799, but over the years the definitions of the metre and the kilogram have been refined, and the metric system has been extended to incorporate many more units. Although a number of variants of the metric system emerged in the late nineteenth and early twentieth centuries, the term is now often used as a synonym for "SI" or the " International System of Units "—the official system of measurement in almost every country in the world. The metric system has been officially sanctioned for use in the United States since 1866, but the U.S. remains the only industrialised country that has not fully adopted the metric system as its official system of measurement, although, in 1988, the United States Congress passed the Omnibus Foreign Trade and Competitiveness Act , which designates "the metric system of measurement as the preferred system of weights and measures for U.S. trade and commerce". Among many other things, the act requires federal agencies to use metric measurements in nearly all of its activities, although there are still some exceptions allowing traditional linear units to be used in documents intended for consumers [...More...]  "Metric System" on: Wikipedia Yahoo 

System Of Measurement A SYSTEM OF MEASUREMENT is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and commerce . Systems of measurement in modern use include the metric system , the imperial system , and United States United States customary units . CONTENTS* 1 History * 1.1 Current practice * 2 Metric system * 3 Imperial and US customary units * 4 Natural units * 5 Nonstandard units * 5.1 Area * 5.2 Energy Energy * 6 Units of currency * 7 Historical systems of measurement * 7.1 Africa * 7.2 Asia * 7.3 Europe * 7.4 North America * 7.5 Oceania * 7.6 South America * 8 See also * 8.1 Conversion tables * 9 Notes and references * 10 Bibliography * 11 External links HISTORY Main article: History of measurement The French Revolution gave rise to the metric system , and this has spread around the world, replacing most customary units of measure. In most systems, length (distance), mass , and time are _base quantities_. Later science developments showed that either electric charge or electric current could be added to extend the set of base quantities by which many other metrological units could be easily defined. (However, electrical units are not necessary for such a set [...More...]  "System Of Measurement" on: Wikipedia Yahoo 

Coherence (units Of Measurement) A COHERENT DERIVED UNIT is defined as a derived unit that, for a given system of quantities and for a chosen set of base units , is a product of powers of base units with no other proportionality factor than one. The concept of coherence was developed in the midnineteenth century by, amongst others, Kelvin and James Clerk Maxwell and promoted by the British Association for the Advancement of Science . The concept was initially applied to the centimetre–gram–second (CGS) and the foot–pound–second systems (FPS) of units in 1873 and 1875 respectively. The International System of Units (1960) was designed around the system of coherence. CONTENTS * 1 Basic concepts * 2 Before the metric system * 2.1 Relating quantities of the same kind * 2.2 Relating quantities of different kinds * 3 Metric system * 3.1 Rational system and use of water * 3.2 Dimensionrelated coherence * 4 Catalogue of coherent relations * 4.1 SI * 4.2 CGS * 4.3 FPS * 5 See also * 6 References BASIC CONCEPTSIn SI, which is a coherent system, the unit of power is the watt which is defined as one joule per second. In the US customary system of measurement, which is noncoherent, the unit of power is the horsepower which is defined as 550 footpounds per second (the pound in this context being the poundforce ); similarly the gallon is not equal to a cubic yard (nor is it the cube of any length unit) [...More...]  "Coherence (units Of Measurement)" on: Wikipedia Yahoo 

Units Of Measurement A UNIT OF MEASUREMENT is a definite magnitude of a quantity , defined and adopted by convention or by law, that is used as a standard for measurement of the same quantity. Any other value of that quantity can be expressed as a simple multiple of the unit of measurement. For example, length is a physical quantity . The metre is a unit of length that represents a definite predetermined length. When we say 10 metres (or 10 m), we actually mean 10 times the definite predetermined length called "metre". The definition, agreement, and practical use of units of measurement have played a crucial role in human endeavour from early ages up to this day. Different systems of units used to be very common. Now there is a global standard, the International System of Units International System of Units (SI), the modern form of the metric system . In trade, WEIGHTS AND MEASURES is often a subject of governmental regulation, to ensure fairness and transparency. The International Bureau of Weights and Measures (BIPM) is tasked with ensuring worldwide uniformity of measurements and their traceability to the International System of Units International System of Units (SI). Metrology is the science for developing nationally and internationally accepted units of weights and measures [...More...]  "Units Of Measurement" on: Wikipedia Yahoo 

SI Base Unit The International System of Units International System of Units (SI) defines seven units of measure as a basic set from which all other SI units can be derived . The SI BASE UNITS and their physical quantities are the metre for measurement of length , the kilogram for mass , the second for time , the ampere for electric current , the kelvin for temperature , the candela for luminous intensity , and the mole for amount of substance . The SI base units form a set of mutually independent dimensions as required by dimensional analysis commonly employed in science and technology. The names and symbols of SI base units are written in lowercase, except the symbols of those named after a person, which are written with an initial capital letter. For example, the metre (US English: meter) has the symbol m, but the kelvin has symbol K, because it is named after Lord Kelvin Kelvin and the ampere with symbol A is named after AndréMarie Ampère AndréMarie Ampère . Other units, such as the litre (US English: liter), are formally not part of the SI, but are accepted for use with SI [...More...]  "SI Base Unit" on: Wikipedia Yahoo 

Metric Prefix A METRIC PREFIX is a unit prefix that precedes a basic unit of measure to indicate a multiple or fraction of the unit. While all metric prefixes in common use today are decadic , historically there have been a number of binary metric prefixes as well. Each prefix has a unique symbol that is prepended to the unit symbol. The prefix _kilo _, for example, may be added to _gram_ to indicate _multiplication_ by one thousand: one kilogram is equal to one thousand grams. The prefix _milli _, likewise, may be added to _metre_ to indicate _division_ by one thousand; one millimetre is equal to one thousandth of a metre. Decimal multiplicative prefixes have been a feature of all forms of the metric system , with six dating back to the system's introduction in the 1790s. Metric prefixes have even been prepended to nonmetric units. The SI PREFIXES are standardized for use in the International System of Units (SI) by the International Bureau of Weights and Measures (BIPM) in resolutions dating from 1960 to 1991. Since 2009, they have formed part of the International System of Quantities [...More...]  "Metric Prefix" on: Wikipedia Yahoo 

MKS System Of Units The MKS SYSTEM OF UNITS is a physical system of units that expresses any given measurement using base units of the metre , kilogram , and/or second (MKS). Historically the use of the MKS system of units succeeded the centimetre–gram–second system of units (CGS) in commerce and engineering, (1889). The metre and kilogram system served as the basis for the development of the International System of Units , which now serves as the international standard. Because of this, the standards of the CGS system were gradually replaced with metric standards incorporated from the MKS system. The exact list of units used in the MKS system changed over time. It incorporated base units other than the metre, kilogram, and second in addition to derived units. An incomplete list of the base and derived units appears below. Since the MKS system of units never had a governing body to rule on a standard definition, the list of units depended on different conventions at different times. * Cycle (This dimensionless quantity became synonymous with the term "cycle per second" as an abbreviation. This circumstance confused the exact definition of the term cycle. Therefore, the phrase "cycle per metre" became illdefined [...More...]  "MKS System Of Units" on: Wikipedia Yahoo 

Centimetre–gram–second System Of Units The CENTIMETRE–GRAM–SECOND SYSTEM OF UNITS (abbreviated CGS or CGS) is a variant of the metric system based on the centimetre as the unit of length , the gram as the unit of mass , and the second as the unit of time . All CGS mechanical units are unambiguously derived from these three base units, but there are several different ways of extending the CGS system to cover electromagnetism . The CGS system has been largely supplanted by the MKS system based on the metre , kilogram , and second, which was in turn extended and replaced by the International System of Units International System of Units (SI). In many fields of science and engineering, SI is the only system of units in use but there remain certain subfields where CGS is prevalent. In measurements of purely mechanical systems (involving units of length, mass, force , energy , pressure , and so on), the differences between CGS and SI are straightforward and rather trivial; the unitconversion factors are all powers of 10 as 100 cm = 1 m and 1000 g = 1 kg. For example, the CGS unit of force is the dyne which is defined as 1 g·cm/s2, so the SI unit of force, the newton (1 kg·m/s2), is equal to 100,000 dynes. On the other hand, in measurements of electromagnetic phenomena (involving units of charge , electric and magnetic fields, voltage , and so on), converting between CGS and SI is more subtle [...More...]  "Centimetre–gram–second System Of Units" on: Wikipedia Yahoo 

General Conference On Weights And Measures The GENERAL CONFERENCE ON WEIGHTS AND MEASURES (French : _Conférence générale des poids et mesures_ – CGPM) is the senior of the three Intergovernmental organizations established in 1875 under the terms of the Metre Convention (French : _Convention du Mètre_) to represent the interests of member states. The treaty, which also set up two further bodies, the International Committee for Weights and Measures (French : _Comité international des poids et mesures_ – CIPM) and the International Bureau of Weights and Measures (French : _Bureau international des poids et mesures_ – BIPM), was drawn up to coordinate international metrology and to coordinate the development of the metric system . The conference meets in Sèvres (southwest of Paris) every four to six years. Initially it was only concerned with the kilogram and the metre , but in 1921 the scope of the treaty was extended to accommodate all physical measurements and hence all aspects of the metric system . In 1960 the 11th CGPM approved the _Système International d\'Unités _, usually known as "SI". CONTENTS* 1 Establishment * 1.1 Membership criteria * 2 CGPM meetings * 3 See also * 4 Notes * 5 References ESTABLISHMENTOn 20 May 1875 an international treaty known as the _Convention du Mètre_ ( Metre Convention ) was signed by 17 states [...More...]  "General Conference On Weights And Measures" on: Wikipedia Yahoo 

Kilogram The KILOGRAM or KILOGRAMME ( SI unit symbol: KG) is the base unit of mass in the International System of Units (SI) (the Metric system ) and is defined as being equal to the mass of the _International Prototype of the Kilogram_ (IPK, also known as "Le Grand K" or "Big K"). The avoirdupois (or _international_) pound , used in both the imperial and US customary systems, is defined as exactly 6999453592370000000♠0.45359237 kg, making one kilogram approximately equal to 2.2046 avoirdupois pounds. Other traditional units of weight and mass around the world are also defined in terms of the kilogram, making the IPK the primary standard for virtually all units of mass on Earth [...More...]  "Kilogram" on: Wikipedia Yahoo 

Discipline (academia) An ACADEMIC DISCIPLINE or ACADEMIC FIELD is a branch of knowledge . It incorporates expertise, people, projects, communities, challenges, studies, inquiry, and research areas that are strongly associated with a given scholastic subject area or college department. For example, the branches of science are commonly referred to as the scientific disciplines, e.g. physics , mathematics , and computer science . Individuals associated with academic disciplines are commonly referred to as _experts _ or _specialists_. Others, who may have studied liberal arts or systems theory rather than concentrating in a specific academic discipline, are classified as _generalists_. While academic disciplines in and of themselves are more or less focused practices, scholarly approaches such as multidisciplinarity , interdisciplinarity , transdisciplinarity , and crossdisciplinarity integrate aspects from multiple academic disciplines, therefore addressing any problems that may arise from narrow concentration within specialized fields of study. For example, professionals may encounter trouble communicating across academic disciplines because of differences in language or specified concepts. Some researchers believe that academic disciplines may be replaced by what is known as Mode 2 or "postacademic science", which involves the acquisition of crossdisciplinary knowledge through collaboration of specialists from various academic disciplines [...More...]  "Discipline (academia)" on: Wikipedia Yahoo 

Metre Convention METRE CONVENTION (French: _Convention du Mètre_), also known as the TREATY OF THE METRE, is an international treaty that was signed in Paris on 20 May 1875 by representatives of 17 nations. (Argentina, AustriaHungary, Belgium, Brazil, Denmark, France, Germany, Italy, Peru, Portugal, Russia, Spain, Sweden and Norway, Switzerland, Turkey, United States of America and Venezuela). The treaty set up an institute for the purpose of coordinating international metrology and for coordinating the development of the metric system . The treaty also set up associated organizations to oversee the running of the institute. Initially it was only concerned with the units of mass and length but, in 1921, at the 6th meeting of the General Conference on Weights and Measures (CGPM), it was revised and its mandate extended to cover all physical measurements. In 1960, at the 11th meetings of the CGPM, the system of units it had established was overhauled and relaunched as the " International System of Units " (SI) [...More...]  "Metre Convention" on: Wikipedia Yahoo 

Metrication METRICATION or METRIFICATION is conversion to the metric system of units of measurement . Worldwide, there has been a long process of independent conversions of countries from various local and traditional systems, beginning in France during the 1790s and spreading widely over the following two centuries, but the metric system has not been fully adopted in all countries and sectors. An example of metrication in 1860 when Tuscany became part of modern Italy CONTENTS * 1 Overview * 2 Before the metric system * 3 Forerunners of the metric system * 4 Conversion process * 4.1 Chronology and status of conversion by country * 5 Exceptions * 5.1 United Kingdom * 5.2 United States and Canada * 5.3 Air and sea transportation * 6 Accidents and incidents * 7 See also * 8 References * 9 External links OVERVIEWSince 2006, three countries formally do not use the metric system as their main standard of measurement: the United States , Myanmar , and Liberia . In the United Kingdom metric is the official system for most regulated trading by weight or measure purposes, but some imperial units remain the primary official unit of measurement. For example, miles , yards , and feet remain the official units for road signage – and use of imperial units is widespread [...More...]  "Metrication" on: Wikipedia Yahoo 