Historical weights and measures - Historical weights and measures Many systems of weights and measures have existed throughout history. The definitions of some of these units were often vague and inaccurate, and although the roots of many of the units were the same, the actual value of a unit differed from country to country, or epoch to epoch. That fact should not lead to a conclusion that historical units of measure were inaccurate in general. Many units were defined to a high precision, and standards of measurement were in many cases excellent. As a case in point, the Great Pyramid of Giza was built to a precision of 15 mm over sides that are 235 m, over four and a half thousand years ago. Table of contents showTocToggle("show","hide") 1 Mesopotamian system.
Weights and measures - Weights and measures The definition, agreement and practical use of units of weights and measures have played a crucial role in human endavour from early ages up to this day. Just to underline the importance of agreed units, the NASA Mars Polar Lander in December 1999 crashed on the planet Mars instead of staying in orbit, due to miscommunications about the value of forces: different people used different assumptions about the unit of measure (newton versus pound). Enormous amounts of effort, time and money were wasted. Table of contents showTocToggle("show","hide") 1 History of Weights and Measures 2 Origins of common customary units 2.1 Units of length 2.2 Typographical units 2.3 Units of mass 2.4 Units of time and angle 3 Origin of the metric system 4.
Georg Agricola - philology and philosophy had accustomed him to systematic thinking, and this enabled him to construct out of his studies and observations of minerals a logical system which he began to publish in 1528. Agricola's dialogue Bermannus, sive de re metallica dialogus, (1530) the first attempt to reduce to scientific order the knowledge won by practical work, brought Agricola into notice; it contained an approving letter from Erasmus at the beginning of the book. In 1530 Prince Maurice of Saxony appointed him historiographer with an annual allowance, and he migrated to Chemnitz, the centre of the mining industry, in order to widen the range of his observations. The citizens showed their appreciation of his learning by appointing him town physician in 1533. In that year, he published a book about Greek and.
Geographical mile - defined to be exactly 1852 metres. The Danish and German geographical mile (mil and Meile) is 4 minutes of arc, and was defined as 7421.5 metres by the astronomer Ole Rømer of Denmark. In Norway and Sweden, this geographical mile was only used at sea. See also historical weights and measures. In France there was also a geographical league, see historical weights and measures. See mile for the various other miles in use, and also conversion of units..
Great Pyramid of Giza - limestone, creating smooth sides; they have since fallen out, or been recycled for other building projects, leaving the underlying step-pyramid structure visible. (The smooth outer cover is still visible at the very top of Khafre's pyramid.) The great pyramid differs in its internal arrangement from the other pyramids in the area. The greater number of passages and chambers, the high finish of parts of the work, and the accuracy of construction all distinguish it. The chamber which is most normal in its situation is the subterranean chamber; but this is quite unfinished, hardly more than begun. The upper chambers, called the king's and queen's, were completely hidden, the ascending passage to them having been closed by plugging blocks, which concealed the point where it branched upwards out of the roof of.
Units unit conversion program - is a Unix computer program for conversion of units of weights and measures. It has a huge database of units, including esoteric and historical units. This for instance allows you to convert velocities specified in furlongs per fortnight, if you really wish. The database units.dat, in plain text format, is in fact a good source of information in itself. units has been a standard part of Unix since the early Bell Laboratories versions. The GNU free software version is written by Adrian Mariano..
Foot (unit of length) - was adapted from an Egyptian measure by the Greeks, with a subsequent larger foot being adopted by the Romans. In addition to the current standard imperial foot, there is also a slightly different U.S. survey foot, used only by the U.S. Coast and Geodetic Survey, defined as exactly 12 U.S. survey inches, approximately 30.48006 cm. (See inch for more on the survey inch.) See also Historical weights and measures.
Eratosthenes - actual circumference of the Earth around the poles is 40,008 km. Eratosthenes' method was used by Posidonius about 150 years later. Circa 200 BC Eratosthenes adopted a word geography, which means a description of the Earth. Eartosthenes' other contributions include: The Sieve of Eratosthenes as a way of finding prime numbers. The measurement of the Sun-Earth distance, now called the astronomical unit (804,000,000 stadia). The measurement of the distance to the Moon (780,000 stadia). The measurement of the inclination of the ecliptic with an angle error 7'. He compiled a star catalogue containing 675 stars, which was not preserved. A map of the Nile's route to Khartoum. A map of the entire known world, from the British Isles to Ceylon, and from the Caspian Sea to Ethiopia. Only Hipparchus, Strabo, and.
30th century BC - Early Dynastic Period I in Mesopotamia. Significant persons: Inventions, Discoveries, Introductions: The shekal was introduced in Mesopotamia as a monetary and weight unit, see Historical weights and measures..
Abbreviation - to add an apostrophe for a plural, e.g., kms vs km's. The apostrophe is not needed grammatically but sometimes is added to make it clear that the s is not part of the abbreviation. In Chinese, abbreviations can be formed by using key characterss. For example, the renmin daibiao dahui (National People's Congress) becomes ren da. Alternatively, there may be a set of classical characters which are shorter and more formal, as in the case of Chinese provinces. see also: initialism, list of initialisms, acronym, list of acronyms, apocopation, TLA, Wikipedia disambiguation of abbreviations, Internet slang, list of computing and IT abbreviations, list of medical abbreviations, list of government and military acronyms, abbreviations used in CIA World Factbook, ISO language code, ISO country code. Initially based on a British encyclopedia published.
Amedeo Avogadro - de Physique, de Chemie et d'Histoire naturelle and it was published in the edition of July 14, 1811 with the title Essai d'une manière de déterminer les masses relatives des molecules élémentaires des corps, et les proportions selon lesquelles elles entrent dans ces combinaisons (complete English text here: [1] - First page: [1]). Avogadro's Law implies that the relationship occurring between the weights of same volumes of different gases (at the same temperature and pressure) corresponds to the relationship between respective molecular weights. Hence, relative molecular weights can be calculated from the weights of gases. Avogadro developed this hypothesis after Joseph Louis Gay-Lussac had published in 1808 his law on volumes (and combining gases). The greatest difficulty Avogadro had to resolve was the huge confusion at that time regarding atoms and.
Cubit - one person's forearm tended to be a different length to the next person's, a standardised Royal Master Cubit, or Sacred Cubit, was cut in granite. This was 7 palms or 28 digits long, and was used in the construction of buildings and monuments (such as the pyramids) and in surveying. The inch, foot, and yard are thought to be connected to the cubit through a complicated transformation not yet fully understood. Some believe they evolved from cubic measures; others believe they were simple proportions or multiples of the cubit. See also: Historical weights and measures.
Twelve - polygon is a dodecagon. A twelve-sided polyhedron is a dodecahedron. The number twelve is often used as a sales unit in trade, and is often referred to as a dozen. Twelve dozen are known as a gross. (Note that there are thirteen loaves in a baker's dozen.) The duodecimal system (twelve = 10), which is the use of 12 as a division factor for many historical weights and measures, including hours, probably originates from Mesopotamia. See also: base 12. As Schoolhouse Rock explains in its song "Little Twelvetoes", if man had been born with twelve fingers, he would have counted and multiplied using the duodecimal system. In English, twelve is the number of greatest magnitude that has just one syllable. In base thirteen and higher bases (such as hexadecimal), twelve is.
Rise of Rome - at the very tail end of the original Roman Empire. First of four examples of world government The Roman Empire is one of the four undisputed well-documented examples of a sustained military and political domination of one people and world-view over all others they encounter - an active seeking of world government. The other three are the Islamic caliphate which created today's Islamic World, the Spanish Empire which dominated and largely colonized the New World, the British Empire which succeeded it, and today's global economic monoculture (English-speaking) led by the United States of America which in turn succeeded that. While China, India and Russia were largely independent of the earlier empires, none have now managed to escape alliances with the newer ones. Thus the study of the rise of such empires.
Physical unit - useful. Reproducibility of experimental results is central to the scientific method. To facilitate this we need standards, and to get convenient measures of the standards we need a system of units. Scientific systems of units are a formalization of the concept of weights and measures, initially developed for commercial purposes. Different systems of units are based on different choices of a set of fundamental units. The most widely used system of units is the international system, or SI system, of units derived from the seven SI base units. All other SI units can be derived from these base units. Other systems of units that have been used for various purposes include: the centimeter-gram-second system of units the Planck units U.S. customary units Imperial units Chinese unit Table of contents showTocToggle("show","hide") 1.
Measurement - boat can be given as the number of times that person's foot would fit the length of the boat. Laws to regulate measurement were originally developed to prevent fraud. However, units of measurement are now generally defined on a scientific basis, and are established by international treaties. The history of measurements is a topic within the History of Science and Technology. The meter was standardized as the unit for length after the French revolution, and has since been adopted throughout most of the world. The United States and the UK are in the process of converting to the SI system. This process is known as metrication. Systems of measurement: Imperial units SI system, also known as the metric system Chinese units Measuring the ratios between physical quantities is an important sub-field.
Mile - navigation, the geographical mile was commonly used, defined as 1 minute of arc along the Earth's equator, approximately equal to 1855 metres. The name statute mile goes back to Queen Elizabeth I of England who redefined the mile from 5000 feet to 5280 feet by statute in 1593. When the international mile was agreed upon in 1959, the survey mile was retained for measurements derived from US geodetic surveys. In Denmark and most of Germany the mile in the 19th century was an approx. 7.5 km geographical mile (determined by 4 minutes of arc) specified by Ole Rømer. In parts of Germany there also existed an exact 7.5 km metric mile variant, but it mostly went out of use at the beginning of the 20th century. The Ole Rømer mile was.
League - meaning varying in different countries. In Argentina a league is a distance of 5 km. In Yucatan and other parts of rural Mexico the league is still commonly used in the original sense of the distance that can be covered on foot in an hour, so that a league along a good road on level ground is a greater distance than a league on a difficult path over rough terrain. The French liegue exists in several variants, all in the neighborhood of 4 km. Its use overlaps the metric system. See Historical weights and measures for various definitions of the league. League (chuulghan in Mongolian) was an administrative unit in Mongolia during the Qing Dynasty. It still exists in Inner Mongolia. A league consisted of several banners. The head of a.
Libra - the scorpion's claws, is the youngest of the Zodiac and the only one not to represent a living being. In Greek mythology, the constellation depicts the scales held by Astraea (the Virgin), the goddess of justice. Astrology The astrological sign Libra (September 23 - October 22) is associated with the constellation. In some cosmologies, Libra is associated with the classical element Air, and thus called an Air Sign (with Aquarius and Gemini). Its polar opposite is Aries. Constellations of the zodiac : Aries -- Taurus -- Gemini -- Cancer -- Leo -- Virgo -- Libra -- Scorpius -- (Ophiuchus) -- Sagittarius -- Capricornus -- Aquarius -- Pisces Libra is also a Roman coin and weight measure, see Historical weights and measures.
List of reference tables - standards topics (these could easily be cross-referenced under other relevant categories as well) International Standards ISO 639 language names ISO 3166 country codes Time zones List of country calling codes List of Internet TLDs List of plastic recycling codes United States Standards Federal Standard 1037C (Glossary of telecommunication terms) List of FIPS country codes US postal abbreviations Size, measurement and conversionss List of size, measurement and conversions topics (these could easily be cross-referenced under other relevant categories as well) SI base units SI derived units SI prefix Unit conversions Orders of magnitude orders of magnitude (length) orders of magnitude (area) orders of magnitude (volume) orders of magnitude (mass) orders of magnitude (time) Specific measures Cooking weights and measures Historical weights and measures Vedic units of time Paper sizes ISO 216 paper.
