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Oxford Electric Bell
The Oxford Electric Bell or Clarendon Dry Pile is an experimental electric bell, in particular a type of bell that uses the electrostatic clock principle that was set up in 1840 and which has run nearly continuously ever since. It was one of the first pieces purchased for a collection of apparatus by clergyman and physicist Robert Walker. It is located in a corridor adjacent to the foyer of the Clarendon Laboratory at the University of Oxford, England, and is still ringing, albeit inaudibly due to being behind two layers of glass. Design The experiment consists of two brass bells, each positioned beneath a dry pile (a form of battery), the pair of piles connected in series, giving the bells opposite electric charges. The clapper is a metal sphere approximately in diameter suspended between the piles, which rings the bells alternately due to electrostatic force. When the clapper touches one bell, it is charged by that pile. It is then repelled from that bell due to having the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxford Electric Bell
The Oxford Electric Bell or Clarendon Dry Pile is an experimental electric bell, in particular a type of bell that uses the electrostatic clock principle that was set up in 1840 and which has run nearly continuously ever since. It was one of the first pieces purchased for a collection of apparatus by clergyman and physicist Robert Walker. It is located in a corridor adjacent to the foyer of the Clarendon Laboratory at the University of Oxford, England, and is still ringing, albeit inaudibly due to being behind two layers of glass. Design The experiment consists of two brass bells, each positioned beneath a dry pile (a form of battery), the pair of piles connected in series, giving the bells opposite electric charges. The clapper is a metal sphere approximately in diameter suspended between the piles, which rings the bells alternately due to electrostatic force. When the clapper touches one bell, it is charged by that pile. It is then repelled from that bell due to having the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Today, almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere The greatest commercial use of the element is the production o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1840 Works
__NOTOC__ Year 184 ( CLXXXIV) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Eggius and Aelianus (or, less frequently, year 937 ''Ab urbe condita''). The denomination 184 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place China * The Yellow Turban Rebellion and Liang Province Rebellion break out in China. * The Disasters of the Partisan Prohibitions ends. * Zhang Jue leads the peasant revolt against Emperor Ling of Han of the Eastern Han Dynasty. Heading for the capital of Luoyang, his massive and undisciplined army (360,000 men), burns and destroys government offices and outposts. * June – Ling of Han places his brother-in-law, He Jin, in command of the imperial army and sends them to attack the Yellow Turban rebels. * Winter – Zha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
European Journal Of Physics
The ''European Journal of Physics'' is a peer-reviewed, scientific journal dedicated to maintaining and improving the standard of physics education in higher education. The journal, published since 1980, is now published by IOP Publishing on behalf of the European Physical Society. The current editor-in-chief is Mojca Čepič of the Ljubljana University, Slovenia. It does not include original research in physics, but rather: *Surveys of research at a level accessible to students *Original insights into the derivation of results *Descriptions of new laboratory exercises *Scholarly or reflective articles at appropriate levels *Descriptions of successful original student projects *Discussions of the history and philosophy of physics. *Reports of new developments in methods for teaching physics and in the physics curriculum. The journal had an Impact factor of 0.781 for 2020, according to the Journal Citation Reports. It is indexed In Chemical Abstracts, Engineering Index/Ei C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Clock Of The Long Now
The Clock of the Long Now, also called the 10,000-year clock, is a mechanical clock under construction that is designed to keep time for 10,000 years. It is being built by the Long Now Foundation. A two-meter prototype is on display at the Science Museum, London, Science Museum in London. , two more prototypes are on display at The Long Now Museum & Store at Fort Mason Center in San Francisco. The project was conceived by Danny Hillis in 1986. The first prototype of the clock began working on December 31, 1999, just in time to display the transition to the year 2000. At midnight on New Year's Eve, the date indicator changed from 01999 to 02000, and the chime (bell instrument), chime struck twice. The manufacture and site construction of the first full-scale prototype clock is being funded by Jeff Bezos's Bezos Expeditions, with $42 million, and is on land which Bezos owns in Texas. Purpose In the words of Stewart Brand, a founding board member of the foundation, "Such a clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitch Drop Experiment
A pitch drop experiment is a long-term experiment which measures the flow of a piece of pitch over many years. 'Pitch' is the name for any of a number of highly viscous liquids which appear solid, most commonly bitumen, also known as asphalt. At room temperature, tar pitch flows at a very low rate, taking several years to form a single drop. University of Queensland experiment The best-known version of the experiment was started in 1927 by Professor Thomas Parnell of the University of Queensland in Brisbane, Australia, to demonstrate to students that some substances which appear solid are highly viscous fluids. Parnell poured a heated sample of the pitch into a sealed funnel and allowed it to settle for three years. In 1930, the seal at the neck of the funnel was cut, allowing the pitch to start flowing. A glass dome covers the funnel and it is placed on display outside a lecture theatre. Large droplets form and fall over a period of about a decade. The seventh drop fell at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beverly Clock
The Beverly Clock is a clock in the 3rd-floor lift foyer of the Department of Physics at the University of Otago, Dunedin, New Zealand. The clock is still running despite never having been manually wound since its construction in 1864 by Arthur Beverly. Operation The clock's mechanism is driven by variations in atmospheric pressure, and by daily temperature variations; of the two, temperature variations are more important. Either causes the air in a airtight box to expand or contract, which pushes on a diaphragm. A temperature variation of over the course of each day creates approximately enough pressure to raise a one- pound weight by one inch (equivalent to ), which drives the clock mechanism. A similar mechanism in a commercially available clock that operates on the same principle is the Atmos clock, manufactured by the Swiss watchmaker Jaeger-LeCoultre. While the clock has not been wound since it was made, it has stopped on a number of occasions, such as when its mechan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franklin Bells
Franklin bells (also known as Gordon's Bells or lightning bells) are an early demonstration of electric charge designed to work with a Leyden jar. Franklin bells are only a qualitative indicator of electric charge and were used for simple demonstrations rather than research. This was the first device that converted electrical energy into mechanical energy in the form of continuous mechanical motion, in this case, the moving of a bell clapper back and forth between two oppositely charged bells. History This device is named for Benjamin Franklin, an early adopter who used it during his experimentation with electricity. It was invented by the Scottish inventor Andrew Gordon, Professor of Natural Philosophy at the University of Erfurt, Germany. About 1742 he invented a device known as the "electric chimes", which was widely described in textbooks of electricity. Franklin made use of Gordon's idea by connecting one bell to his pointed lightning rod, attached to a chimney, and a sec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long-term Experiment
A long-term experiment is an experimental procedure that runs through a long period of time, in order to test a hypothesis or observe a phenomenon that takes place at an extremely slow rate. What duration is considered "long" depends on the academic discipline. For example, several agricultural field experiments have run for more than 100 years, but much shorter experiments may qualify as "long-term" in other disciplines. An experiment is "a set of actions and observations", implying that one or more treatments (fertilizer, subsidized school lunches, etc.) is imposed on the system under study. Long-term experiments therefore contrast with nonexperimental long-term studies in which manipulation of the system studied is impossible (e.g. Jupiter's Great Red Spot) or undesirable (e.g. field observations of chimpanzee behavior). In physics The Oxford Electric Bell has been ringing at Oxford University since 1840, although there is some reason to believe it may be 15 years older. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tintinnabulation
{{Short pages monitor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perpetual Motion
Perpetual motion is the motion of bodies that continues forever in an unperturbed system. A perpetual motion machine is a hypothetical machine that can do work infinitely without an external energy source. This kind of machine is impossible, as it would violate either the first law of thermodynamics, first or second law of thermodynamics or both. These laws of thermodynamics apply regardless of the size of the system. For example, the motions and rotations of celestial bodies such as planets may appear perpetual, but are actually subject to many processes that slowly dissipate their kinetic energy, such as solar wind, interstellar medium resistance, gravitational radiation and thermal radiation, so they will not keep moving forever. Thus, machines that extract energy from finite sources will not operate indefinitely, because they are driven by the energy stored in the source, which will eventually be exhausted. A common example is devices powered by ocean currents, whose energ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrochemistry
Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference, as a measurable and quantitative phenomenon, and identifiable chemical change, with the potential difference as an outcome of a particular chemical change, or vice versa. These reactions involve electrons moving via an electronically-conducting phase (typically an external electrical circuit, but not necessarily, as in electroless plating) between electrodes separated by an ionically conducting and electronically insulating electrolyte (or ionic species in a solution). When a chemical reaction is driven by an electrical potential difference, as in electrolysis, or if a potential difference results from a chemical reaction as in an electric battery or fuel cell, it is called an ''electrochemical'' reaction. Unlike in other chemical reactions, in electrochemical reactions electrons are not transferred directly between atoms, ions, or molecules, but via the af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
