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Kelvin Water Dropper
The Kelvin water dropper, invented by Scottish scientist William Thomson, 1st Baron Kelvin, William Thomson (Lord Kelvin) in 1867, is a type of electrostatic generator. Kelvin referred to the device as his water-dropping condenser. The apparatus is variously called the Kelvin hydroelectric generator, the Kelvin electrostatic generator, or Lord Kelvin's thunderstorm. The device uses falling water to generate voltage differences by electrostatic induction occurring between interconnected, oppositely Electric charge, charged systems. This eventually leads to an electric arc discharging in the form of a spark. It is used in physics education to demonstrate the principles of electrostatics. Description A typical setup is shown in Fig. 1. A reservoir of water or other conducting liquid (top, grey) is connected to two hoses that release two falling streams of drops, which land in two buckets or containers (bottom, blue and red). Each stream passes (without touching) through a metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin (26 June 182417 December 1907), was a British mathematician, Mathematical physics, mathematical physicist and engineer. Born in Belfast, he was the Professor of Natural Philosophy (Glasgow), professor of Natural Philosophy at the University of Glasgow for 53 years, where he undertook significant research on the mathematical analysis of electricity, was instrumental in the formulation of the first and second laws of thermodynamics, and contributed significantly to unifying physics, which was then in its infancy of development as an emerging academic discipline. He received the Royal Society's Copley Medal in 1883 and served as its President of the Royal Society, president from 1890 to 1895. In 1892, he became the first scientist to be elevated to the House of Lords. Absolute temperatures are stated in units of kelvin in Lord Kelvin's honour. While the existence of a coldest possible temperature, absolute zero, was known before his work, Kelvin d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Energy
In physics, the kinetic energy of an object is the form of energy that it possesses due to its motion. In classical mechanics, the kinetic energy of a non-rotating object of mass ''m'' traveling at a speed ''v'' is \fracmv^2.Resnick, Robert and Halliday, David (1960) ''Physics'', Section 7-5, Wiley International Edition The kinetic energy of an object is equal to the work, or force ( F) in the direction of motion times its displacement ( s), needed to accelerate the object from rest to its given speed. The same amount of work is done by the object when decelerating from its current speed to a state of rest. The SI unit of energy is the joule, while the English unit of energy is the foot-pound. In relativistic mechanics, \fracmv^2 is a good approximation of kinetic energy only when ''v'' is much less than the speed of light. History and etymology The adjective ''kinetic'' has its roots in the Greek word κίνησις ''kinesis'', meaning "motion". The dichoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIT OCW
MIT OpenCourseWare (MIT OCW) is an initiative of the Massachusetts Institute of Technology (MIT) to publish all of the educational materials from its undergraduate- and graduate-level courses online, freely and openly available to anyone, anywhere. The project was announced on April 4, 2001, and uses the Creative Commons Attribution-NonCommercial-ShareAlike license. The program was originally funded by the William and Flora Hewlett Foundation, the Andrew W. Mellon Foundation, and MIT. MIT OpenCourseWare is supported by MIT, corporate underwriting, major gifts, and donations from site visitors. The initiative inspired a number of other institutions to make their course materials available as open educational resources. As of May 2018, over 2,400 courses were available online. While a few of these were limited to chronological reading lists and discussion topics, a majority provided homework problems and exams (often with solutions) and lecture notes. Some courses also included i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Electricity
Atmospheric electricity describes the electrical charges in the Earth's atmosphere (or that of another planet). The movement of charge between the Earth's surface, the atmosphere, and the ionosphere is known as the global atmospheric electrical circuit. Atmospheric electricity is an interdisciplinary topic with a long history, involving concepts from electrostatics, atmospheric physics, meteorology and Earth science. Thunderstorms act as a giant battery in the atmosphere, charging up the electrosphere to about 400,000 volts with respect to the surface. This sets up an electric field throughout the atmosphere, which decreases with increase in altitude. Atmospheric ions created by cosmic rays and natural radioactivity move in the electric field, so a very small current flows through the atmosphere, even away from thunderstorms. Near the surface of the Earth, the magnitude of the field is on average around 100 V/m, oriented such that it drives positive charges down. Atmospheric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Priestley
Joseph Priestley (; 24 March 1733 – 6 February 1804) was an English chemist, Unitarian, Natural philosophy, natural philosopher, English Separatist, separatist theologian, Linguist, grammarian, multi-subject educator and Classical liberalism, classical liberal Political philosophy, political theorist. He published over 150 works, and conducted experiments in several areas of science. Priestley is credited with his independent discovery of oxygen by the thermal decomposition of mercuric oxide, having isolated it in 1774. During his lifetime, Priestley's considerable scientific reputation rested on his invention of carbonated water, his writings on electricity, and his discovery of several "airs" (gases), the most famous being what Priestley dubbed "dephlogisticated air" (oxygen). Priestley's determination to defend phlogiston theory and to reject what would become the chemical revolution eventually left him isolated within the scientific community. Priestley's science was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Theophilus Desaguliers
John Theophilus Desaguliers (12 March 1683 – 29 February 1744) was a French-born British natural philosopher, clergyman, engineer and freemason who was elected to the Royal Society in 1714 as experimental assistant to Isaac Newton. He had studied at Oxford and later popularized Newtonian theories and their practical applications in public lectures. Desaguliers's most important patron was James Brydges, 1st Duke of Chandos. As a Freemason, Desaguliers was instrumental in the success of the first Grand Lodge in London in the early 1720s and served as its third Grand Master. Biography Early life and education Desaguliers was born in La Rochelle, several months after his father Jean Desaguliers, a Protestant minister, had been exiled as a Huguenot by the French government. Jean Desaguliers was ordained as an Anglican by Bishop Henry Compton of London, and sent to Guernsey. Meanwhile, the baby was baptised Jean Théophile Desaguliers in the Protestant Temple in La Rochelle, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taylor Cone
A Taylor cone refers to the cone observed in electrospinning, electrospraying and hydrodynamic spray processes from which a jet of charged particles emanates above a threshold voltage. Aside from electrospray ionization in mass spectrometry, the Taylor cone is important in field-emission electric propulsion (FEEP) and colloid thrusters used in fine control and high efficiency (low power) thrust of spacecraft. History This cone was described by Sir Geoffrey Ingram Taylor in 1964 before electrospray was "discovered". This work followed on the work of Zeleny who photographed a cone-jet of glycerine in a strong electric field and the work of several others: Wilson and Taylor (1925), Nolan (1926) and Macky (1931). Taylor was primarily interested in the behavior of water droplets in strong electric fields, such as in thunderstorms. Formation When a small volume of electrically conductive liquid is exposed to an electric field, the shape of liquid starts to deform from the shape ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Gilbert (physician)
William Gilbert (; 24 May 1544? – 30 November 1603), also known as Gilberd, was an English physician, physicist and natural philosopher. He passionately rejected both the prevailing Aristotelian philosophy and the Scholastic method of university teaching. He is remembered today largely for his book '' De Magnete'' (1600). A unit of magnetomotive force, also known as magnetic potential, was named the '' Gilbert'' in his honour; it has now been superseded by the Ampere-turn. Life and work Gilbert was born in Colchester to Jerome Gilberd, a borough recorder. He was educated at St John's College, Cambridge. After gaining his MD from Cambridge in 1569, and a short spell as bursar of St John's College, he left to practice medicine in London, and he travelled on the continent. In 1573, he was elected a Fellow of the Royal College of Physicians. In 1600, he was elected President of the college.Mottelay, P. Fleury (1893). "Biographical memoir". In He was Elizabeth I's own ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Magnete
''De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure'' (''On the Magnet and Magnetic Bodies, and on That Great Magnet the Earth'') is a scientific work published in 1600 by the English physician and scientist William Gilbert. A highly influential and successful book, it exerted an immediate influence on many contemporary writers, including Francis Godwin and Mark Ridley. Contents In ''De Magnete'', Gilbert described many of his experiments with his model Earth called the '' terrella''. Gilbert made the claim that gravity was due to the same force and he believed that this held the Moon in orbit around the Earth. The work then considered static electricity produced by amber. Amber is called ''elektron'' in Greek, and ''electrum'' in Latin, so Gilbert decided to refer to the phenomenon by the adjective ''electricus''. Summary ''De Magnete'' consists of six books. Book 1 Historical survey of magnetism and theory of Earth's magnetism. The lodestone in antiq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Twente
The University of Twente ( ; Abbreviation, abbr. ) is a Public university, public technical university located in Enschede, Netherlands. The university has been placed in the top 170 universities in the world by multiple central ranking tables. In addition, the UT was ranked the best technical university in the Netherlands by Keuzegids Universiteiten, the most significant national university ranking. The UT collaborates with Delft University of Technology, Eindhoven University of Technology and the Wageningen University and Research Centre under the umbrella of 3TU, 4TU and is also a partner in the European Consortium of Innovative Universities (ECIU). History The university was founded in 1961 as ''Technische Hogeschool Twente'' (''THT''). After Delft University of Technology and Eindhoven University of Technology, it became the third polytechnic institute in the Netherlands to become a university. The institution was later renamed to Universiteit Twente (University of Twente) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Van De Graaff Generator
A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate electric charge on a hollow metal globe on the top of an insulated column, creating very high electric potentials. It produces very high voltage direct current (DC) electricity at low current levels. It was invented by American physicist Robert J. Van de Graaff in 1929. The potential difference achieved by modern Van de Graaff generators can be as much as 5 megavolts. A tabletop version can produce on the order of 100 kV and can store enough energy to produce visible electric sparks. Small Van de Graaff machines are produced for entertainment, and for physics education to teach electrostatics; larger ones are displayed in some science museums. The Van de Graaff generator was originally developed as a particle accelerator for physics research, as its high potential can be used to accelerate subatomic particles to great speeds in an evacuated tube. It was the most powerful type of ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
