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Leslie's Cube
Leslie's cube is a device used in the measurement or demonstration of the variations in thermal radiation emitted from different surfaces at the same temperature. Device It was devised in 1804 by John Leslie (1766–1832), a Scottish mathematician and physicist. In the version of the experiment described by John Tyndall in the late 1800s, one of the cube's vertical sides is coated with a layer of gold, another with a layer of silver, a third with a layer of copper, while the fourth side is coated with a varnish of isinglass. The cube is made from a solid block of metal with a central cavity. In use, the cavity was filled with hot water; the entire cube has essentially the same temperature as the water. The thermal detector (on the far right in the figure) showed much greater emission from the side with varnish than from any of the other three sides. In contemporary terms, the emissivities of shiny metals are low. Isinglass is an organic glue, and has a much larger emissivity th ...
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Leslie Cube
Leslie's cube is a device used in the measurement or demonstration of the variations in thermal radiation emitted from different surfaces at the same temperature. Device It was devised in 1804 by John Leslie (1766–1832), a Scottish mathematician and physicist. In the version of the experiment described by John Tyndall in the late 1800s, one of the cube's vertical sides is coated with a layer of gold, another with a layer of silver, a third with a layer of copper, while the fourth side is coated with a varnish of isinglass. The cube is made from a solid block of metal with a central cavity. In use, the cavity was filled with hot water; the entire cube has essentially the same temperature as the water. The thermal detector (on the far right in the figure) showed much greater emission from the side with varnish than from any of the other three sides. In contemporary terms, the emissivities of shiny metals are low. Isinglass is an organic glue, and has a much larger emissivity t ...
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Blackbody Radiation
Black-body radiation is the thermal electromagnetic radiation within, or surrounding, a body in thermodynamic equilibrium with its environment, emitted by a black body (an idealized opaque, non-reflective body). It has a specific, continuous spectrum of wavelengths, inversely related to intensity, that depend only on the body's temperature, which is assumed, for the sake of calculations and theory, to be uniform and constant., Chapter 13. A perfectly insulated enclosure which is in thermal equilibrium internally contains black-body radiation, and will emit it through a hole made in its wall, provided the hole is small enough to have a negligible effect upon the equilibrium. The thermal radiation spontaneously emitted by many ordinary objects can be approximated as black-body radiation. Of particular importance, although planets and stars (including the Earth and Sun) are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is sti ...
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1804 In Science
The year 1804 in science and technology involved some significant events, listed below. Astronomy and space science * April 5 – High Possil meteorite, the first recorded meteorite to fall in Scotland in modern times, falls at Possil. * September 1 – Karl Ludwig Harding discovers the asteroid Juno. Botany * March 7 – John Wedgwood founds the Horticultural Society of London. * Jacques-Julien Labillardière begins publication of '' Novæ Hollandiæ Plantarum Specimen'' in Paris, the first flora of Australia. * Publication in Paris of Nicolas-Théodore de Saussure's collected papers ''Recherches chimiques sur la végétation'', outlining the basic reaction of photosynthesis. * Publication in London of Maria Elizabetha Jacson's ''Botanical Lectures by a Lady''. Chemistry * William Hyde Wollaston discovers how to make malleable platinum. * German pharmacist Friedrich Sertürner first isolates morphine from opium, probably the first ever isolation of a natural plant alk ...
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1804 Introductions
Eighteen or 18 may refer to: * 18 (number), the natural number following 17 and preceding 19 * one of the years 18 BC, AD 18, 1918, 2018 Film, television and entertainment * ''18'' (film), a 1993 Taiwanese experimental film based on the short story ''God's Dice'' * ''Eighteen'' (film), a 2005 Canadian dramatic feature film * 18 (British Board of Film Classification), a film rating in the United Kingdom, also used in Ireland by the Irish Film Classification Office * 18 (''Dragon Ball''), a character in the ''Dragon Ball'' franchise * "Eighteen", a 2006 episode of the animated television series '' 12 oz. Mouse'' Music Albums * ''18'' (Moby album), 2002 * ''18'' (Nana Kitade album), 2005 * '' 18...'', 2009 debut album by G.E.M. Songs * "18" (5 Seconds of Summer song), from their 2014 eponymous debut album * "18" (One Direction song), from their 2014 studio album ''Four'' * "18", by Anarbor from their 2013 studio album '' Burnout'' * "I'm Eighteen", by Alice Cooper commo ...
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Radiometry
Radiometry is a set of techniques for measurement, measuring electromagnetic radiation, including visible light. Radiometric techniques in optics characterize the distribution of the radiation's power (physics), power in space, as opposed to photometry (optics), photometric techniques, which characterize the light's interaction with the human eye. The fundamental difference between radiometry and photometry is that radiometry gives the entire optical radiation spectrum, while photometry is limited to the visible spectrum. Radiometry is distinct from quantum optics, quantum techniques such as photon counting. The use of radiometers to determine the temperature of objects and gasses by measuring radiation flux is called pyrometry. Handheld pyrometer devices are often marketed as infrared thermometers. Radiometry is important in astronomy, especially radio astronomy, and plays a significant role in Earth remote sensing. The measurement techniques categorized as ''radiometry'' in op ...
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William Blackwood
William Blackwood (20 November 177616 September 1834) was a Scottish publisher who founded the firm of William Blackwood and Sons. Life Blackwood was born in Edinburgh on 20 November 1776. At the age of 14 he was apprenticed to a firm of booksellers in Edinburgh, and he followed his calling also in Glasgow and London for several years. Returning to Edinburgh in 1804, he opened a shop in South Bridge Street for the sale of old, rare and curious books. He undertook the Scottish agency for John Murray and other London publishers, and gradually drifted into publishing on his own account, moving in 1816 to Princes Street. On 1 April 1817 the first number of the ''Edinburgh Monthly Magazine'' was published, which on its seventh number became ''Blackwood's Edinburgh Magazine''. "''Maga''," as this magazine soon came to be called, was the organ of the Scottish Tory party, and round it gathered a host of writers, including John Neal, making Maga the first British literary journal to ...
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Macedonio Melloni
Macedonio Melloni (11 April 1798 – 11 August 1854) was an Italian physicist, notable for demonstrating that radiant heat has similar physical properties to those of light. Life Born at Parma, in 1824 he was appointed professor at the local University but was compelled to escape to France after taking part in the revolution of 1831. In 1839 he went to Naples and was soon appointed director of the Vesuvius Observatory, a post that he held until 1848. In 1845, he was elected a foreign member of the Royal Swedish Academy of Sciences. He died at Portici, near Naples, of cholera, aged 56. Work Melloni's reputation as a physicist rests principally on his discoveries in radiant heat, made with the aid of the ''thermomultiplier'', a combination of thermopile and galvanometer. In 1831, soon after the discovery of thermoelectricity by Thomas Johann Seebeck, he and Leopoldo Nobili employed the instrument in experiments especially concerned with characteristics of (in modern language) blac ...
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Harper And Brothers
Harper is an American publishing house, the flagship imprint of global publisher HarperCollins based in New York City. History J. & J. Harper (1817–1833) James Harper and his brother John, printers by training, started their book publishing business J. & J. Harper in New York City in 1817. Their two brothers, Joseph Wesley and Fletcher, joined them in the mid-1820s. Harper & Brothers (1833–1962) The company changed its name to "Harper & Brothers" in 1833. The headquarters of the publishing house were located at 331 Pearl Street, facing Franklin Square in Lower Manhattan (about where the Manhattan approach to the Brooklyn Bridge lies today). Harper & Brothers began publishing ''Harper's New Monthly Magazine'' in New York City in 1850. The brothers also published ''Harper's Weekly'' (starting in New York City in June 1857), '' Harper's Bazar'' (starting in New York City in November 2, 1867), and ''Harper's Young People'' (starting in New York City in 1879). George B. M ...
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Leslie Cube Draper
Leslie may refer to: * Leslie (name), a name and list of people with the given name or surname, including fictional characters Families * Clan Leslie, a Scottish clan with the motto "grip fast" * Leslie (Russian nobility), a Russian noble family of Scottish origin Places Canada * Leslie, Saskatchewan * Leslie Street, a road in Toronto and York Region, Ontario ** Leslie (TTC), a subway station ** Leslie Street Spit, an artificial spit in Toronto United States * Leslie, Arkansas *Leslie, Georgia *Leslie, Michigan *Leslie, Missouri *Leslie, West Virginia * Leslie, Wisconsin *Leslie Township, Michigan *Leslie Township, Minnesota Elsewhere * Leslie Dam, a dam in Warwick, Queensland, Australia * Leslie, Mpumalanga, South Africa * Leslie, Aberdeenshire, Scotland, see List of listed buildings in Leslie, Aberdeenshire * Leslie, Fife, Scotland, UK Other uses * Leslie speaker system * Leslie Motor Car company * Leslie Controls, Inc. * Leslie (singer) Leslie Bourgouin, bette ...
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Emissivity
The emissivity of the surface of a material is its effectiveness in emitting energy as thermal radiation. Thermal radiation is electromagnetic radiation that most commonly includes both visible radiation (light) and infrared radiation, which is not visible to human eyes. A portion of the thermal radiation from very hot objects (see photograph) is easily visible to the eye. The emissivity of a surface depends on its chemical composition and geometrical structure. Quantitatively, it is the ratio of the thermal radiation from a surface to the radiation from an ideal black surface at the same temperature as given by the Stefan–Boltzmann law. The ratio varies from 0 to 1. The surface of a perfect black body (with an emissivity of 1) emits thermal radiation at the rate of approximately 448 watts per square metre at room temperature (, ). All real objects have emissivities less than 1.0, and emit radiation at correspondingly lower rates. Emissivities are important in several conte ...
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FUNcube-1
FUNcube-1 is a complete educational single unit CubeSat satellite with the goal of enthusing and educating young people about radio, space, physics and electronics. It is part of a program which aims to launch more of these educational CubeSats. It is the first satellite with outreach as its primary mission. FUNcube project Project The FUNcube project was started in the UK by AMSAT-UK. The satellite has been developed by a team of volunteers from AMSAT-UK and AMSAT-NL, and was assembled at ISIS in Delft. It has been designated with OSCAR number 73 by AMSAT and is now also known as AO-73. Mission As part of its mission, FUNcube-1 carries a materials science experiment, from which the school students can receive telemetry data and which they can compare to the results they obtained from similar reference experiments in the classroom. This experiment resembles the Leslie's Cube experiment. One of the first schools to use FUNcube-1 in the classroom was ''Abbeys Primary School'' ...
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Thermal Radiation
Thermal radiation is electromagnetic radiation generated by the thermal motion of particles in matter. Thermal radiation is generated when heat from the movement of charges in the material (electrons and protons in common forms of matter) is converted to electromagnetic radiation. All matter with a temperature greater than absolute zero emits thermal radiation. At room temperature, most of the emission is in the infrared (IR) spectrum. Particle motion results in charge-acceleration or dipole oscillation which produces electromagnetic radiation. Infrared radiation emitted by animals (detectable with an infrared camera) and cosmic microwave background radiation are examples of thermal radiation. If a radiation object meets the physical characteristics of a black body in thermodynamic equilibrium, the radiation is called blackbody radiation. Planck's law describes the spectrum of blackbody radiation, which depends solely on the object's temperature. Wien's displacement law de ...
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