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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 th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 that depends only on the body's temperature., Chapter 13. A perfectly-insulated enclosure which is in thermal equilibrium internally contains blackbody 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 blackbody 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, blackbody radiation is still a good first approximation for the energy they emit. The term ''black body'' was introduced by Gustav Kirchhoff in 1860. Blackbody radiati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 * June 21 – Smithson Tennant announces the discovery of the elements iridium and osmium; three days later, William Hyde Wollaston reveals to the Royal Society that he is the formerly anonymous discove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1804 Introductions
Eighteen or 18 may refer to: * 18 (number) * 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'' Science * Argon, a noble gas in the periodic table * 18 Melpomene, an asteroid in the asteroid belt Music Albums * ''18'' (Moby album), 2002 * ''18'' (Nana Kitade album), 2005 * '' 18...'', 2009 debut album by G.E.M. * ''18'' (Jeff Beck and Johnny Depp album), 2022 Songs * "18" (5 Seconds of Summer song), from their 2014 eponymous debut album * "18" (One Direction song), from their 2014 studio album ''Four'' * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 (later known as William Blackwood and Sons), moving in 1816 to Princes Street. That same year, Blackwood convinced Walter Scott to abandon Archibald Constable as his Edinburgh publisher. Blackwood's first deal as publisher was the next novel in Scott's '' Tales of my Landlord'' series. On 1 April 1817, the first number of the ''Edinburgh Monthly Magazine'' was published, which on its seventh nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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) b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harper And Brothers
Harper is an American publishing house, the flagship imprint of global publisher HarperCollins, based in New York City. Founded in New York in 1817 by James Harper and his brother John, the company operated as J. & J. Harper until 1833, when it changed its name to Harper & Brothers, reflecting the inclusion of Joseph and Fletcher Harper. Harper began publishing ''Harper's Magazine'', ''Harper's Weekly'', and other periodicals beginning in the 1850s. From 1962 to 1990, the company was known as Harper & Row after its merger with Row, Peterson & Company. Harper & Row was purchased in 1987 by News Corporation and combined with William Collins, Sons, its United Kingdom counterpart, in 1990 to form HarperCollins, although the Harper name has been used in its place since 2007. 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 We ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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) (born 1985), French singer * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 black body, ideal black surface at the same temperature as given by the Stefan–Boltzmann law. (A comparison with Planck's law is used if one is concerned with particular wavelengths of thermal radiation.) 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 (W/m) at a room temperature of . Objects have emi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Radiation
Thermal radiation is electromagnetic radiation emitted by the thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. The emission of energy arises from a combination of electronic, molecular, and lattice oscillations in a material. Kinetic energy is converted to electromagnetism due to charge-acceleration or dipole oscillation. At room temperature, most of the emission is in the infrared (IR) spectrum, though above around 525 °C (977 °F) enough of it becomes visible for the matter to visibly glow. This visible glow is called incandescence. Thermal radiation is one of the fundamental mechanisms of heat transfer, along with conduction and convection. The primary method by which the Sun transfers heat to the Earth is thermal radiation. This energy is partially absorbed and scattered in the atmosphere, the latter process being the reason why the sky is visibly blue. Much of the Sun's radiation tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
