Coherent Unit
A coherent system of units is a system of units of measurement used to express physical quantities that are defined in such a way that the equations relating the numerical values expressed in the units of the system have exactly the same form, including numerical factors, as the corresponding equations directly relating the quantities. A coherent derived unit is a SI derived unit, derived unit that, for a given system of quantities and for a chosen set of Base unit (measurement), base units, is a product of powers of base units, with the proportionality factor being one. If a system of quantities has equations that relate quantities and the associated system of units has corresponding base units, with one base unit for each base quantity, then it is coherent if and only if every derived unit of the system is coherent. The concept of coherence was developed in the mid-nineteenth century by, amongst others, William Thomson, 1st Baron Kelvin, Kelvin and James Clerk Maxwell and promo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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James Clerk Maxwell
James Clerk Maxwell (13 June 1831 – 5 November 1879) was a Scottish mathematician and scientist responsible for the classical theory of electromagnetic radiation, which was the first theory to describe electricity, magnetism and light as different manifestations of the same phenomenon. Maxwell's equations for electromagnetism have been called the " second great unification in physics" where the first one had been realised by Isaac Newton. With the publication of "A Dynamical Theory of the Electromagnetic Field" in 1865, Maxwell demonstrated that electric and magnetic fields travel through space as waves moving at the speed of light. He proposed that light is an undulation in the same medium that is the cause of electric and magnetic phenomena. (This article accompanied an 8 December 1864 presentation by Maxwell to the Royal Society. His statement that "light and magnetism are affections of the same substance" is at page 499.) The unification of light and electrical ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ancient China
The earliest known written records of the history of China date from as early as 1250 BC, from the Shang dynasty (c. 1600–1046 BC), during the reign of king Wu Ding. Ancient historical texts such as the '' Book of Documents'' (early chapters, 11th century BC), the '' Bamboo Annals'' (c. 296 BC) and the ''Records of the Grand Historian'' (c. 91 BC) describe a Xia dynasty before the Shang, but no writing is known from the period, and Shang writings do not indicate the existence of the Xia. The Shang ruled in the Yellow River valley, which is commonly held to be the cradle of Chinese civilization. However, Neolithic civilizations originated at various cultural centers along both the Yellow River and Yangtze River. These Yellow River and Yangtze civilizations arose millennia before the Shang. With thousands of years of continuous history, China is among the world's oldest civilizations and is regarded as one of the cradles of civilization. The Zhou dynasty (1046–256 BC) supp ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Finger (unit)
A finger (sometimes fingerbreadth or finger's breadth) is any of several units of measurement that are approximately the width of an adult human finger, including: The digit, also known as digitus or digitus transversus (Latin), dactyl (Greek) or dactylus, or finger's breadth — of an inch or of a foot. In medicine and related disciplines (anatomy, radiology, etc.) the fingerbreadth (literally the width of a finger) is an informal but widely used unit of measure. In the measurement of distilled spirits, a finger of whiskey refers to the amount of whiskey that would fill a glass to the level of one finger wrapped around the glass at the bottom. Another definition (from Noah Webster): "nearly an inch." Finger is also the name of a longer unit of length used in cloth measurement, specifically, one eighth of a yard or 4 inches. In English these units have mostly fallen out of use, apart from the common use in distilled drinks and drinking games. See also * Digit (unit) * ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Barley
Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley production is used as animal fodder, while 30% as a source of fermentable material for beer and certain distilled beverages, and as a component of various foods. It is used in soups and stews, and in barley bread of various cultures. Barley grains are commonly made into malt in a traditional and ancient method of preparation. In 2017, barley was ranked fourth among grains in quantity produced () behind maize, rice and wheat. Etymology The Old English word for barley was ', which traces back to Proto-Indo-European and is cognate to the Latin word ' "flour" (''see corresponding entries''). The direct ancestor of modern English ''barley'' in Old English was the derived adjective ''bærlic'', meaning "of barley". The first citation of t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Naram-Sin Of Akkad
Naram-Sin, also transcribed Narām-Sîn or Naram-Suen ( akk, : '' DNa-ra-am D Sîn'', meaning "Beloved of the Moon God Sîn", the "𒀭" being a silent honorific for "Divine"), was a ruler of the Akkadian Empire, who reigned c. 2254–2218 BC (middle chronology), and was the third successor and grandson of King Sargon of Akkad. Under Naram-Sin the empire reached its maximum strength. He was the first Mesopotamian king known to have claimed divinity for himself, taking the title "God of Akkad", and the first to claim the title "King of the Four Quarters, King of the Universe". As part of that he became city god of Akkade in the same way Enlil was city god of Nippur. Biography Naram-Sin was born as a son of Manishtushu. He was thus a nephew of King Rimush and grandson of Sargon and Tashlultum. Naram-Sin's aunt was the High Priestess En-hedu-ana. To be fully correct, rather than Naram-Sin or Naram-Suen "in Old Akkadian, the name in question should rather be reconstructed as Nar ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Akkadian Empire
The Akkadian Empire () was the first ancient empire of Mesopotamia after the long-lived civilization of Sumer. It was centered in the city of Akkad (city), Akkad () and its surrounding region. The empire united Akkadian language, Akkadian and Sumerian language, Sumerian speakers under one rule. The Akkadian Empire exercised influence across Mesopotamia, the Levant, and Anatolia, sending military expeditions as far south as Dilmun and Magan (civilization), Magan (modern Saudi Arabia, Bahrain, and Oman) in the Arabian Peninsula.Mish, Frederick C., Editor in Chief. "Akkad" ''Webster’s Ninth New Collegiate Dictionary''. ninth ed. Springfield, MA: Merriam-Webster 1985. ). The Akkadian Empire reached its political peak between the 24th and 22nd centuries BC, following the conquests by its founder Sargon of Akkad. Under Sargon and his successors, the Akkadian language was briefly imposed on neighboring conquered states such as Elam and Gutian people, Gutium. Akkad is sometimes regar ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and community outreach. Considered the first learned society in the United States, it has about 1,000 elected members, and by April 2020 had had only 5,710 members since its creation. Through research grants, published journals, the American Philosophical Society Museum, an extensive library, and regular meetings, the society supports a variety of disciplines in the humanities and the sciences. Philosophical Hall, now a museum, is just east of Independence Hall in Independence National Historical Park; it was designated a National Historic Landmark in 1965. History The Philosophical Society, as it was originally called, was founded in 1743 by Benjamin Franklin, James Alexander (lawyer), James Alexander, Francis Hopkinson, John Bartram, Philip Syn ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Hand (unit)
The hand is a non- SI unit of measurement of length standardized to . It is used to measure the height of horses in many English-speaking countries, including Australia, Canada, the Republic of Ireland, the United Kingdom, and the United States. It was originally based on the breadth of a human hand. The adoption of the international inch in 1959 allowed for a standardized imperial form and a metric conversion. It may be abbreviated to "h" or "hh". Although measurements between whole hands are usually expressed in what appears to be decimal format, the subdivision of the hand is not decimal but is in base 4, so subdivisions after the radix point are in quarters of a hand, which are inches. Thus, 62 inches is fifteen and a half hands, or 15.2 hh (normally said as "fifteen-two", or occasionally in full as "fifteen hands two inches"). Terminology "Hands" may be abbreviated to "h", or "hh". The "hh" form is sometimes interpreted as standing for "hands high". When spoken a ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ancient Egyptian Units Of Measurement
Ancient history is a time period from the beginning of writing and recorded human history to as far as late antiquity. The span of recorded history is roughly 5,000 years, beginning with the Sumerian cuneiform script. Ancient history covers all continents inhabited by humans in the period 3000 BCAD 500. The three-age system periodizes ancient history into the Stone Age, the Bronze Age, and the Iron Age, with recorded history generally considered to begin with the Bronze Age. The start and end of the three ages varies between world regions. In many regions the Bronze Age is generally considered to begin a few centuries prior to 3000 BC, while the end of the Iron Age varies from the early first millennium BC in some regions to the late first millennium AD in others. During the time period of ancient history, the world population was already exponentially increasing due to the Neolithic Revolution, which was in full progress. While in 10,000 BC, the world population stood ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Biblical And Talmudic Units Of Measurement
Biblical and Talmudic units of measurement were used primarily by ancient Israelites and appear frequently within the Hebrew Bible as well as in later rabbinic writings, such as the Mishnah and Talmud. These units of measurement continue to be used in functions regulating Jewish contemporary life. The specificity of some of the units used and which are encompassed under these systems of measurement (whether in linear distance, weight or volume of capacity) have given rise, in some instances, to disputes, owing to the discontinuation of their Hebrew names and their replacement by other names in modern usage. Note: The listed measurements of this system range from the lowest to highest acceptable halakhic value, in terms of conversion to and from contemporary systems of measurement. Contemporary unit conversion While documentation on each unit's relation to another's is plentiful, there is much debate, both within Judaism and in academia, about the exact relationship between mea ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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History Of Measurement Systems In India
The history of measurement systems in India begins in early Indus Valley civilisation with the earliest surviving samples dated to the 5th millennium BCE.Iwata, 2254 Since early times the adoption of standard weights and measures has reflected in the country's architectural, folk, and metallurgical artifacts. A complex system of weights and measures was adopted by the Maurya empire (322–185 BCE), which also formulated regulations for the usage of this system. Later, the Mughal empire (1526–1857) used standard measures to determine land holdings and collect land tax as a part of Mughal land reforms. The formal metrication in India is dated to 1 October 1958 when the Indian Government adopted the International System of Units (SI). Early history Standard weights and measures were developed by the Indus Valley Civilization. The centralised weight and measure system served the commercial interest of Indus merchants as smaller weight measures were used to measure luxu ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ancient Mesopotamian Units Of Measurement
Ancient Mesopotamian units of measurement originated in the loosely organized city-states of Early Dynastic Sumer. Each city, kingdom and trade guild had its own standards until the formation of the Akkadian Empire when Sargon of Akkad issued a common standard. This standard was improved by Naram-Sin, but fell into disuse after the Akkadian Empire dissolved. The standard of Naram-Sin was readopted in the Ur III period by the Nanše Hymn which reduced a plethora of multiple standards to a few agreed upon common groupings. Successors to Sumerian civilization including the Babylonians, Assyrians, and Persians continued to use these groupings. Akkado-Sumerian metrology has been reconstructed by applying statistical methods to compare Sumerian architecture, architectural plans, and issued official standards such as Statue B of Gudea and the bronze cubit of Nippur. Archaic system The systems that would later become the classical standard for Mesopotamia were developed in pa ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |