Metrication
From Freepedia
Metrication or metrification is the process of converting from the various other systems of units used throughout the world to the SI metric system. This process began in France in the 1790s and spread over the following two centuries to all but four countries, representing 95 percent of the world's population. The process was completed in most of the world in the 19th and early 20th centuries, replacing numerous historical weights and measures. The countries of the former British Empire (with the exception of the United States) completed metrification during the second half of the 20th century, with Ireland recently completing metrication on January 20, 2005. Today only the United States, Liberia, and Myanmar have not officially switched to the metric system, although Liberia and Myanmar use it in practice; the United Kingdom is currently in the process of conversion. Only France, the United States, the United Kingdom, Canada, and Japan have seen significant popular opposition to metrication, the main objections being based on tradition, aesthetics, and distaste for measures viewed as foreign.
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Before the metric system
- See main article: History of measurement
Medieval trade was organized on a city-by-city basis by guilds, which set local laws on weights and measures. For example, the ell or elle was a unit of length commonly used in Europe, but its value varied from 40.2 cm in one part of Germany to 70 cm in The Netherlands to 94.5 cm in Edinburgh. A survey of Switzerland in 1838 revealed that the foot had 37 different regional variations, the ell had 68, there were 83 different measures for dry grain and 70 for fluids, and 63 different measures for "dead weights."[2] When Isaac Newton wrote his important work Philosophiae Naturalis Principia Mathematica in 1687, he quoted his measurements in Parisian feet so his readers could understand their size. Various efforts were made to have local intercity or national standards for measurements, such as a Scottish law of 1641 and the British standard Imperial unit system of 1845, which is still used for some things in the UK. However, Revolutionary France was to produce the definitive International System of Units which has come to be used by 95% of the world today.
The desire for a single international system of measurement derives from growing international trade and the need to apply common standards to goods. For a company to buy a product produced in another country, they need to be sure that the product will arrive as described. The medieval ell was abandoned in part because its value could not be standardised. It can be argued that the Système International's primary advantage is simply that it is international, and the pressure on countries to conform to it grew as it became increasingly an international standard. SI is not the only example of international standardisation; several powerful international standardisation organisations exist for various industries, such as the International Organization for Standardization, the International Electrotechnical Commission, and the International Telecommunication Union.
Système International
- See main article: International System of Units
Scientists, chiefly in France, had been advocating and discussing a decimal system of measurement based on natural units at least since 1640, but the first official adoption of such a system was after the French Revolution of 1789. The creators of the metric system tried to choose units that were non-arbitrary and practical, merging well with the revolution's official ideology of "pure reason". The original system started with the metre as the unit of distance, the gram as the unit of mass, and the second as the unit of time. Derived units are made from logical combinations of base units. For example, the speed of an object is defined by the number of metres it moves every second — m/s.
An object that is accelerating has a changing speed, so its m/s changes per second, thus the unit is m/s2. The force of a moving object can be described by its mass times its acceleration, thus—kg·m/s2—which is the newton (symbol N), named in honour of Isaac Newton. Further base units dealing with electricity, light and quantities of atoms were added later as these sciences became better understood.
The current version of this system was agreed in 1971 and is organised and maintained by the International Bureau of Weights and Measures. To avoid confusion over the precise value of base units, this organisation also maintains either an international prototype (in the case of a kilogram, a small object of platinum-iridium dubbed "Le Grand Kilo") or a precise recipe on how to recreate the unit, which is decided by the General Conference on Weights and Measures held periodically.
Time has resisted metrication. During the French revolution there was an attempt at a decimal time system with 100 seconds in a minute, 100 minutes in an hour and 10 hours in a day (100,000 seconds in a day as opposed to 86,400 currently—a metric second would be thus 14% shorter). The proposed system also included a ten-day week, which was probably its main reason for failure. The church and the people objected and the system was dropped. It is also interesting to note that China had an almost identical decimal time system up until the 17th century.[1]
The ancient Romans, at one point, had a decimal month system, before they added two extra months.
Conversion process
There are three common routes in converting from traditional measurements to metric, the quick "Big-Bang" route used by India and other pre-industrial nations or the slow "phase-in" route favoured by industrial nations. The first plan is to simultaneously outlaw the use of pre-metric measurement, metricise and reissue all government publications and laws, and change education systems to metric. India's change over lasted between 1 April 1960 when metric became legal, and 1 April 1962 when all other systems were banned. The India model was extremely successful and was copied over much of the developing world. The second possibility is to pass a law permitting the use of metric units in parallel with traditional ones, followed by progressively banning the use of the older measures. This has generally been a slow route to metric. The British Empire permitted the use of metric in 1873, but the changeover was not completed until the 1970s and 1980s when government took an active role in the now-independent parts of the empire. Japan, too, followed this route and did not complete the changeover for 70 years. A third possibility is to redefine traditional units to have metric values. China followed this route, and thus while scientists in China know and use the kilogram, common people retain the jin, which now has a value of 500 g. This route was once proposed for England with the pound to be redefined as 500 g, but the plan did not receive government support. In the Netherlands, 500 g is informally referred to as a pond (pound) and 100 g as an ons (ounce), and in Germany 500 g is informally referred to as ein Pfund (one pound).
It is difficult to judge the degree to which ordinary people change to using metric in their daily lives. In countries that have recently changed, many older people still use the old familiar system. In Canada, ovens and cooking temperatures are usually measured in Fahrenheit, and Canadians almost invariably use Fahrenheit for cooking; this is not necessarily by choice but may instead be due to the overwhelming influence of the neighbouring United States, which does not use the metric system. In the UK, which is in the process of changing over, metric units are often used interchangeably with older measurements. Such countries could be said to be "semi-metric".
Adoption
The metric system, developed in France around the turn of the 19th century, was quickly taken up by Europe's scientists before spreading to traders and industrialists and finally to the common people. France's neighbours, Holland, Belgium, and Luxembourg, changed in 1820. Spain and its former American colonies changed in the 1850s and '60s. Italy and Germany went metric after their respective unifications in 1861 and 1871, followed shortly by Portugal, Norway, Sweden and Austro-Hungarian empire. By 1900, 39 countries in Europe and Latin America were using the metric system.
The first Asian nations to convert were Mongolia (1918), Cambodia and Afghanistan (the 1920s). Japan began its slow conversion process in 1891 when it received a copy of the meter standard from the Institute in France. In 1924, the government decided to replace fully the traditional shaku-kan system within 10 years; however, public opposition delayed implementation. The U.S. occupation of the late 1940s briefly caused a de facto conversion to US customary units. Metrication was completed in Japan by 1969, although some of the old units are still in informal use. India's conversion was far quicker, paradoxically helped by low popular literacy and the fact that there was previously no nationwide standard measurement system—British Imperial units were used by the upper class, while various regional systems were used by the poor. From 1956 to 1961, India simultaneously changed to metric and decimalised its currency.
China began conversion in the 1920s, but the process was not completed until communist times. China also took the unusual step of decimalising their native measurement units and redefining them as even amounts of metric units. Thus jin was redefined to equal 500 grams. The Soviet Union changed from traditional units to metric in 1924.
Those Arab nations which were colonized by France adopted the system early: Algeria changed in 1840, Tunisia in 1890; this was extended to the other Arab countries after the conquest of the Ottoman Empire in 1918. Jordan, which had been a British mandate, was the last Arab nation to convert, in the 1950s. The German colonies of Rwanda and Burundi and the Belgian colony of Zaire were the first sub-Saharan African states to go metric in 1910. French territories in Africa were de facto metric while under French rule. On independence all gradually passed official metric weights and measures laws during the 1950s and 1960s. The last African states to go metric were the former British colonies of southern and eastern Africa.
Britain and its former colonies began their conversion process in the later part of the 20th century. South Africa began a ten-year process of metrication in 1967 with the creation of Metrication Advisory Board, a Metrication Department and a South African Bureau of Standards. Australia began work in 1969 with a publicity campaign involving lecture tours, theatrical advertisements and the free distribution of metric-sized items, including calendars, rulers and A4-sized leaflets. Public opposition was on points of detail only, and the process was declared completed in 1977. Canada and New Zealand followed similar plans in the 1970s. Ireland completed a very gradual changeover process on 20 January 2005 with the conversion of road speed limits to km/h. Ireland began metrication in 1970 when schools switched to teaching only the metric system.
Exceptions
There are three main exceptions to the metrication trend: the UK, the U.S., and global air and sea transport industry. Contrary to popular belief, the U.S. and the UK do not use a common system (see English unit, Imperial unit and U.S. customary units for details). With the exception of the inch, which was standardised at exactly 2.54 cm by an international conference in 1958, most other units differ in value in the U.S. and UK. A gallon of liquid, for example, is 3.8 L in the U.S. but 4.5 L in the UK. The U.S. also has a dry gallon, which is 4.4 L.
United Kingdom
- See also: Metrication in the UK
The UK made initial moves to convert to metric as long ago as 1862, when the Select Committee on Weights and Measures favoured the introduction of decimalisation to accompany the introduction of metric weights and measures.[2] The country finally decimalised their currency a century later in 1971. There is a good deal of public resistance to metrication, which many see as the imposition of a foreign system and to be connected with other unpopular ideas from mainland Europe, such as the EU and the Euro. There has been partial progress, however; metric units have been taught in UK schools since the late 1960s, and certain industries also converted or largely converted decades ago. For example, the paper industry converted in 1970 and the construction industry between 1969 and 1972—although certain products continue to be produced to imperial sizes but with metric size descriptions, for example, as 13 mm (rather than as half-inch) thick plasterboard. However, many consumer products are still sold in traditional units. In August 2005, the European Union announced it would require Britain to set a legal deadline for the completion of metrication.[3]
United States
The United States remains the main exception. Although Thomas Jefferson recommended metrication and currency decimalisation, and metrication is the official policy of the American government since the Convention du Mètre (Metre Convention), and several laws encourage or require use of metric units in various contexts [4], the progress of metrication has been much slower in the United States than in the rest of the world. Non-metric units continue to be predominantly used in everyday life and in commerce, engineering, and aviation. However, change has occurred, with most products in the U.S. now required by law to be labeled with both metric and non-metric units, and a number of companies and government agencies switching to metric standards. Additionally, the metric system is taught in schools, in the context of the sciences.
One peculiar example of this is bottled soft drinks, commonly sold in units of two litres, and with units of 500 mL, one litre, and three litres being less, but increasingly, common. This is a result of the introduction of PET bottling technology coinciding with a particularly strong metrication push in the mid to late 1970s; consumers found that they could buy a two-liter plastic bottle of their favorite soft drink more cheaply than they could four one-pint glass bottles, and the convention stuck. Smaller units, however, continue to be sold more often in fluid ounces, such as 8 ounce (240 mL) and 12 ounce (355 mL) aluminium cans and 20 ounce (591 mL) PET bottles.
The United States continues to use only miles for road distance signs, with the exception of Interstate 19 in Arizona. Originally U.S. legislation set October 2000 as a deadline by which states must undertake construction work and statistics in metric for states to be eligible for federal funding, but that requirement has since been rescinded. Some states have experimented with dual-unit signs, particularly near the borders with Canada and Mexico, but there are as yet no plans for large-scale conversion. There is presently little political support for a comprehensive switch to the metric system.
Liberia and Myanmar
Liberia has used the US system of weights and measures since its founding in the 19th century by freed slaves from the United States. In modern times instability and civil war has meant that measurement reform has not been a high priority and the country in fact uses a mixture of US, metric and local customary measures. Myanmar has not officially adopted "everyday use" of the metric system however unofficial metrication has taken place and the Myanmar economy primarily operates using the metric system.
Air and sea transport
Some industries have resisted metrication. Non-metric measures in air and sea transport retain worldwide dominance. In these areas the nautical mile (1.852 km) is preferred over the kilometre, because it closely represents a minute of arc of the circumference of Earth. While the metre was also based on the Earth with 100 km equal to an arc of 1 gon, those units of angle have not seen widespread use, though they do appear on some maps.
The knot, which is nautical miles per hour, remains the prime unit of speed for maritime and air navigation. (However, before the 1960s, statute miles per hour—which bear no relationship to the Earth—were most often used for this purpose, and remained in fairly common use for some purposes into the 1970s and later.) For aviation, altitudes are usually estimated based on air pressure values and described in nominal feet rather than nominal metres. Since aircraft pilots and air traffic controllers in some regions have long been trained to use non-metric units, the potential threat to air traffic safety is sometimes said to be a reason for not fully adopting metric units. However, the ICAO does not support the view that there is a hazard inherent in metric units. In fact, it is ICAO stated policy to standardise on SI units. Several countries and air forces (mainly, but not only former Warsaw Pact) use metres for altitude.
Accidents
Confusion over units during the process of metrication can sometimes lead to accidents. One of the most famous examples is the Gimli Glider, a Boeing 767 that ran out of fuel in Canada in 1983 due, in large part, to confusion at Air Canada during Canada's metrication.
While not strictly an example of national metrication, the use of two different systems was the contributing factor in the loss of the Mars Climate Orbiter in 1998. The manufacturer of the spacecraft had designed the navigation system to be programmed in metric units, whereas the ground software at NASA's Jet Propulsion Laboratory in Pasadena, California, used one unit from the customary system. The multi-million dollar spacecraft crashed into Mars.
Opposition
- See main article: Metrication arguments and counter-arguments
France experienced a particularly rough journey to metrication. The traditional French measuring system was chaotic, with size of units differing in each small town, and often even within towns. Lyon had two different values of pound in general use, one of 14 ounces and another of 15 ounces, which was only used for measuring silk. The revolutionary government, which had ordered the creation of the metric system, first attempted a quick conversion, legalising metric in 1795 and banning use of traditional units just four years later. Massive popular opposition led Napoleon to rollback these reforms after coming to power. He publicly denounced the previous government for "tormenting people with trifles". It appears that it was decimalisation that disturbed the people most — as although Napoleon decreed that there should be "such fractions and multiples as were generally used", he redefined the old base units in terms of metric. The original metric system was made law again in France in 1837.[2]
Few countries experience much popular opposition to metrication. Many, such as 19th-century Europe, Russia, India and China, converted before most of their populations were literate, and so the initial conversion affected few people. For others, such as Ireland, the previous system was also seen as foreign and unloved. Japan also saw popular resistance to their 1920s metrication program, where opponents of the metric system believed that the adoption of a foreign measuring system would have a bad influence on national sentiment, cause dislocations in public life, needless expense to the nation, prove disadvantageous to foreign trade, and hurt the national language and culture. In 1933, the government postponed the date of conversion of the first stage by five years, and the date of the second stage by ten years. The process was not finally completed until 1969.
The UK and the U.S. have seen the greatest opposition movements. Many in the UK see it as the imposition of a foreign system, connecting it with other unpopular ideas from mainland Europe, such as the EU, the Euro and driving on the right. The "metric martyrs" were shop owners in the UK who were sent to jail for refusing to label their goods in metric measurements. Such protests appear to have deep traditions in England. Philip Grierson notes that in 1201 the town of Lincoln paid "lavish" fines rather than use government-imposed reformed weights and measures.[1] Complaints against the metric system are mainly based on tradition and aesthetics. In the U.S., there is resistance to the prospect of a ban on traditional units, and to what is seen as a foreign system.
See also
| Metrication by country |
| Australia | Canada | China | India | Ireland | Japan | South Africa | UK | US |
References
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- {{{Author|}}}{{|{{{3}}}}}}|show1| (1995)}}{{{{{Year|}}}}}}|show1|.}} {{|{{{3}}}}}}|show1|[{{{URL}}}}} The Basis of Measurement: Historical Aspects{{|{{{3}}}}}}|show1|]}}{{|{{{3}}}}}}|show1|, {{{Pages}}}}}{{|{{{3}}}}}}|Show1|, Picton Publishing (Chippenham Ltd)}}. {{{ID|}}}
- {{{Author|}}}{{|{{{3}}}}}}|show1| (1995)}}{{{{{Year|}}}}}}|show1|.}} {{|{{{3}}}}}}|show1|[{{{URL}}}}} The Basis of Measurement: Metrication and Current Practice{{|{{{3}}}}}}|show1|]}}{{|{{{3}}}}}}|show1|, {{{Pages}}}}}{{|{{{3}}}}}}|Show1|, Picton Publishing (Chippenham Ltd)}}. {{{ID|}}}
External links
Websites supporting metrication:
- The Metrication Board of Ireland
- The United Kingdom Metric Association campaigns for a total metric switchover in the UK
- Timeline of metric system in UK
- U.S. Metric Association discusses progress of metrication in several countries.
- One Metre: Metric in Canada
Websites opposing metrication:
- Freedom to Measure discusses the freedom to choose a measurement system
- British Weights and Measures Association
Other:
