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John Peter Gassiot
John Peter Gassiot FRS (2 April 1797 – 15 August 1877) lso Gassiottwas an English businessman and amateur scientist. He was particularly associated with public demonstrations of electrical phenomena and the development of the Royal Society. Life Born in London, he joined the Royal Navy as a midshipman. In 1819 he married Elizabeth Scott and the couple had nine sons and three daughters.Harrison (2004) In 1822, he joined in business with Spaniard Sebastian Gonzalez Martinez to create the firm of Martinez Gassiot & Co. selling cigars, sherry and port. He also became an enthusiastic amateur scientist with a particular interest in electricity. He created an amply-provided laboratory at his home on Clapham Common and opened it to his fellow scientists, including James Clerk Maxwell who performed much of his 1860s work on electrical resistance there. Science administrator and populariser Gassiot was a close associate of William Sturgeon and Charles Vincent Walker and the three were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Peter Gassiot
John Peter Gassiot FRS (2 April 1797 – 15 August 1877) lso Gassiottwas an English businessman and amateur scientist. He was particularly associated with public demonstrations of electrical phenomena and the development of the Royal Society. Life Born in London, he joined the Royal Navy as a midshipman. In 1819 he married Elizabeth Scott and the couple had nine sons and three daughters.Harrison (2004) In 1822, he joined in business with Spaniard Sebastian Gonzalez Martinez to create the firm of Martinez Gassiot & Co. selling cigars, sherry and port. He also became an enthusiastic amateur scientist with a particular interest in electricity. He created an amply-provided laboratory at his home on Clapham Common and opened it to his fellow scientists, including James Clerk Maxwell who performed much of his 1860s work on electrical resistance there. Science administrator and populariser Gassiot was a close associate of William Sturgeon and Charles Vincent Walker and the three were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surrey
Surrey () is a ceremonial and non-metropolitan county in South East England, bordering Greater London to the south west. Surrey has a large rural area, and several significant urban areas which form part of the Greater London Built-up Area. With a population of approximately 1.2 million people, Surrey is the 12th-most populous county in England. The most populated town in Surrey is Woking, followed by Guildford. The county is divided into eleven districts with borough status. Between 1893 and 2020, Surrey County Council was headquartered at County Hall, Kingston-upon-Thames (now part of Greater London) but is now based at Woodhatch Place, Reigate. In the 20th century several alterations were made to Surrey's borders, with territory ceded to Greater London upon its creation and some gained from the abolition of Middlesex. Surrey is bordered by Greater London to the north east, Kent to the east, Berkshire to the north west, West Sussex to the south, East Sussex to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatics
Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber, (), was thus the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law. Even though electrostatically induced forces seem to be rather weak, some electrostatic forces are relatively large. The force between an electron and a proton, which together make up a hydrogen atom, is about 36 orders of magnitude stronger than the gravitational force acting between them. There are many examples of electrostatic phenomena, from those as simple as the attraction of plastic wrap to one's hand after it is removed from a package, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetism
Magnetism is the class of physical attributes that are mediated by a magnetic field, which refers to the capacity to induce attractive and repulsive phenomena in other entities. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. Magnetism is one aspect of the combined phenomena of electromagnetism. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetized to become permanent magnets, producing magnetic fields themselves. Demagnetizing a magnet is also possible. Only a few substances are ferromagnetic; the most common ones are iron, cobalt, and nickel and their alloys. The rare-earth metals neodymium and samarium are less common examples. The prefix ' refers to iron because permanent magnetism was first observed in lodestone, a form of natural iron ore called magnetite, Fe3O4. All substances exhibit some type of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bakerian Lecture
The Bakerian Medal is one of the premier medals of the Royal Society that recognizes exceptional and outstanding science. It comes with a medal award and a prize lecture. The medalist is required to give a lecture on any topic related to physical sciences. It is awarded annually to individuals in the field of physical sciences, including computer science. History The prize was started in 1775, when Henry Baker left £100 to establish a spoken lecture given by a Fellow of the Royal Society ''on such part of natural history or experimental philosophy'' as the Society shall determine. Clearly, this is to deliver a lecture of scientific interests and importance, and encourage sharing of knowledge with others. Awardees SourceRoyal Society 21st century *2023 Andrew Zisserman, ''for research on computational theory and commercial systems for geometrical analysis of images, and for being a pioneer and leading scientist in machine learning for vision, especially image recognition'' *202 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum
A vacuum is a space devoid of matter. The word is derived from the Latin adjective ''vacuus'' for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a ''perfect'' vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term ''in vacuo'' is used to describe an object that is surrounded by a vacuum. The ''quality'' of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressure by around 20%. But hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glow Discharge
A glow discharge is a plasma formed by the passage of electric current through a gas. It is often created by applying a voltage between two electrodes in a glass tube containing a low-pressure gas. When the voltage exceeds a value called the striking voltage, the gas ionization becomes self-sustaining, and the tube glows with a colored light. The color depends on the gas used. Glow discharges are used as a source of light in devices such as neon lights, fluorescent lamps, and plasma-screen televisions. Analyzing the light produced with spectroscopy can reveal information about the atomic interactions in the gas, so glow discharges are used in plasma physics and analytical chemistry. They are also used in the surface treatment technique called sputtering. Electrical conduction in gas Conduction in a gas requires charge carriers, which can be either electrons or ions. Charge carriers come from ionizing some of the gas molecules. In terms of current flow, glow discharge falls ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stria (electricity)
Stretch marks, also known as striae () or striae distensae, are a form of scarring on the skin with an off-color hue. Over time they may diminish, but will not disappear completely. Striae are caused by tearing of the dermis during periods of rapid growth of the body, such as during puberty or pregnancy, in which they usually form during the last trimester. Usually on the stomach, these striae also commonly occur on the breasts, thighs, hips, lower back, and buttocks. Pregnancy-related striae are known as ''striae gravidarum''. Striae may also be influenced by the hormonal changes associated with puberty, pregnancy, bodybuilding, or hormone replacement therapy. There is no evidence that creams used during pregnancy prevent stretch marks. Once they have formed there is no clearly effective treatment, though various methods have been attempted and studied. Signs and symptoms Striae, or "stretch marks", begin as reddish or purple lesions, which can appear anywhere on the body, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrostatic Discharge
Electrostatic discharge (ESD) is a sudden and momentary flow of electric current between two electrically charged objects caused by contact, an short circuit, electrical short or dielectric breakdown. A buildup of static electricity can be caused by tribocharging or by electrostatic induction. The ESD occurs when differently-charged objects are brought close together or when the dielectric between them breaks down, often creating a visible electric spark, spark. ESD can create spectacular electric sparks (lightning, with the accompanying sound of thunder, is a large-scale ESD event), but also less dramatic forms which may be neither seen nor heard, yet still be large enough to cause damage to sensitive electronic devices. Electric sparks require a field strength above approximately 40 kV/cm in air, as notably occurs in lightning strikes. Other forms of ESD include corona discharge from sharp electrodes and brush discharge from blunt electrodes. ESD can cause harmful effects of imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grove Cell
The Grove cell was an early electric primary cell named after its inventor, Welsh physical scientist William Robert Grove, and consisted of a zinc anode in dilute sulfuric acid and a platinum cathode in concentrated nitric acid, the two separated by a porous ceramic pot. Cell details The Grove cell voltage is about 1.9 volts and arises from the following reaction: : Zn + H2SO4 + 2 HNO3 ZnSO4 + 2 H2O + 2 NO2↑ Use The Grove cell was the favored power source of the early American telegraph system in the period 1840 – 1860 because it offered a high current output and higher voltage than the earlier Daniell cell (at 1.9 volts and 1.1 volts, respectively). Disadvantages By the time of the American Civil War, as telegraph traffic increased, the Grove cell's tendency to discharge poisonous nitrogen dioxide (NO2) fumes proved increasingly hazardous to health, and as telegraphs became more complex, the need for constant voltage became critical. The Grove cell was limited in this respe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Insulation
An electrical insulator is a material in which electric current does not flow freely. The atoms of the insulator have tightly bound electrons which cannot readily move. Other materials—semiconductors and conductors—conduct electric current more easily. The property that distinguishes an insulator is its resistivity; insulators have higher resistivity than semiconductors or conductors. The most common examples are non-metals. A perfect insulator does not exist because even insulators contain small numbers of mobile charges ( charge carriers) which can carry current. In addition, all insulators become electrically conductive when a sufficiently large voltage is applied that the electric field tears electrons away from the atoms. This is known as the breakdown voltage of an insulator. Some materials such as glass, paper and PTFE, which have high resistivity, are very good electrical insulators. A much larger class of materials, even though they may have lower bulk resistivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Battery (electricity)
An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell. Primary (single-use or "disposable") batteries are used once and discarded, as the electrode materials are irreversibly changed during discharge; a common example is the alkaline battery used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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