International System of Units - a structure which is based on the use of indicators weight in kilograms, and the length in meters.Right from its inception, there were various options for her.The difference between them lies in the selection of core indicators.Today, many countries use the unit of measurement in the SI system.It elements are the same for all countries (except the United States, Liberia, Burma).This system is widely used in various fields - from everyday life to scientific research.
Features
Metric - an ordered set of parameters.This distinguishes it from the previously used traditional methods of determination of certain units.To designate any size metric system uses only one main indicator, the value of which may vary in multiple fractions (achieved by using decimal Extra elements).The main advantage of this approach is easier to use.This eliminates the unnecessary large number of different units (feet, miles, inches, etc.).
Timing
Over a long period by a number of researchers have attempted to present time in metric units.Proposes to divide the day into smaller elements - millisutki and corners - 400 castles or take a full cycle of turnover for 1000 millioborotov.Over time, because of the inconvenience of use had to abandon the idea.Today is the time in seconds, denoted by SI (comprised of milliseconds) and radians.
History of
believed that the modern metric system was born in France.In the period from 1791 to 1795 in the country it was passed glad important legislation.They were aimed at determining the status of a meter - one ten-millionth 1/4 share of the meridian from the equator to the North Pole.July 4, 1837 adopted a special document.According to him, it was approved the mandatory use of the elements of which was the metric system measures all economic transactions carried out in France.Later adopted the structure began to spread to the neighboring countries of Europe.Because of its simplicity and convenience, the metric system is gradually replaced most national used previously.Also, it is acceptable to use in the US and the UK.
Basic quantities
the unit of measurement of length of the founders, as already noted above, took the metro.Element weight became grams - the weight of one million m3 of water in its standard density.For more convenient use of units of the new system creators have come up with a way to make them more accessible - by making the standards of metal.These models are made with perfect fidelity values.Where are the standards of the metric system, it will be discussed below.Subsequently, using these models, people realize that sravnenivat desired value of them is much easier and more convenient than, for example, a quarter of the meridian.At the same time, sought to determine the mass of the body, it became obvious that to assess its quality, the standard is much more convenient than the corresponding amount of water.
"Archive" samples
Resolution of the International Commission in 1872 was adopted as the standard for measuring the length of a specially made meter.At the same time members of the committee decided to accept the standard for measuring the mass of the special kilogram.It was made from alloys of platinum and iridium."Archive" meter and kilogram are permanently stored in Paris.In 1885, on May 20, representatives of seventeen countries signed a special convention.As part of its regulated the procedure for determining the use of standards and measurements in research and writings.This will require a special organization.These include, in particular, the International Bureau of Weights and Measures.As part of the newly created organization began to develop sample weight and length, and then send them copies of all participating countries.
Metric in Russia
samples taken enjoyed more and more countries.Under these circumstances, Russia could not ignore the emergence of a new system.Therefore, the Act of July 4, 1899 (author and developer - Mendeleev) she was allowed to use optionally.She became obligatory only after the adoption of the Provisional Government by decree in 1917.Later, its use has been fixed by the decision of SNK of the 21st July 1925.In the twentieth century, most countries moved to a measure in the international system of units.The final version of it was developed and approved by the General Conference XI in 1960.
post-Soviet time
collapse of the Soviet Union coincided with the rapid development of computer and household appliances, the main production is concentrated in Asia.On the territory of the Russian Federation began to import large consignments of these manufacturers.At the same time Asian states did not think about the possible problems and disadvantages of their products operate Russian-speaking population and supplied its products to the universal (in their view) instruction in English with American settings.In use the designation values of the metric system was superseded by the elements used in the United States.For example, the size of computer disks diagonal monitors and other components are indicated in inches.At the same time the original parameters of these components is strictly designated in terms of the metric system (the width of the CD and DVD, for example, is 120 mm).
International use
Currently, the most widespread on the planet Earth is the metric system.Table mass, length, distance and other parameters makes it easy to translate some other indicators.Countries, for some reason not switched to this system, every year there are fewer and fewer.These states continue to use your own parameters, are the United States, Burma and Liberia.America enjoys in the sectors of scientific production SI system.All other parameters were used US.UK and St Lucia have not yet switched to the global system of SI.But I must say that the process is in an active stage.From the country, finally switched to the metric system in 2005, became the Republic of Ireland.Antigua and Guyana only produce the transition, but the pace is very slow.An interesting situation in China, who officially switched to the metric system, but it continues on its territory the use of ancient Chinese units.
Aviation parameters
Metric recognized almost everywhere.But there are some sectors in which it is not caught.The aircraft is still used system of measurement, which are based on such values as feet and miles.Application of the system in this field historically.Position of the International Civil Aviation Organization is unequivocal - to be a transition to the metric value.However, these recommendations in its pure form hold only a few countries.Among them are Russia, China and Sweden.Moreover, the structure of the Russian civil aviation, to avoid confusion with the international tower, in 2011 took part a system of measures, which is a basic unit of foot.
