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Versorium
The versorium (Latin word for "turn around") was the first electroscope, the first instrument that could detect the presence of static electric charge. It was invented in 1600 by William Gilbert, physician to Queen Elizabeth I. Description The versorium is a needle constructed out of metal which is allowed to pivot freely on a pedestal. It is similar to a compass needle, but unmagnetized. The needle is attracted to charged bodies brought near it, turning towards the charged object. Since it is able to distinguish between charged and non-charged objects, it is an example of a class of devices known as electroscopes. The versorium is of a similar construction to the magnetic compass, but is influenced by electrostatic rather than magnetic forces. At the time it was invented, the differences between magnetic and electrical forces were poorly understood and Gilbert did a series of experiments to prove they were two separate types of forces with the versorium and another device ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Versorium
The versorium (Latin word for "turn around") was the first electroscope, the first instrument that could detect the presence of static electric charge. It was invented in 1600 by William Gilbert, physician to Queen Elizabeth I. Description The versorium is a needle constructed out of metal which is allowed to pivot freely on a pedestal. It is similar to a compass needle, but unmagnetized. The needle is attracted to charged bodies brought near it, turning towards the charged object. Since it is able to distinguish between charged and non-charged objects, it is an example of a class of devices known as electroscopes. The versorium is of a similar construction to the magnetic compass, but is influenced by electrostatic rather than magnetic forces. At the time it was invented, the differences between magnetic and electrical forces were poorly understood and Gilbert did a series of experiments to prove they were two separate types of forces with the versorium and another device ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroscope
The electroscope is an early scientific instrument used to detect the presence of electric charge on a body. It detects charge by the movement of a test object due to the Coulomb electrostatic force on it. The amount of charge on an object is proportional to its voltage. The accumulation of enough charge to detect with an electroscope requires hundreds or thousands of volts, so electroscopes are used with high voltage sources such as static electricity and electrostatic machines. An electroscope can only give a rough indication of the quantity of charge; an instrument that measures electric charge quantitatively is called an electrometer. The electroscope was the first electrical measuring instrument. The first electroscope was a pivoted needle (called the ''versorium''), invented by British physician William Gilbert around 1600. a translation by P. Fleury Mottelay of William Gilbert (1600) ''Die Magnete'', London The pith-ball electroscope and the gold-leaf electroscope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Gilbert (astronomer)
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. 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 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 physician from 1601 until her death in 1603, and James ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrometer
An electrometer is an electrical instrument for measuring electric charge or electrical potential difference. There are many different types, ranging from historical handmade mechanical instruments to high-precision electronic devices. Modern electrometers based on vacuum tube or solid-state technology can be used to make voltage and charge measurements with very low leakage currents, down to 1 femtoampere. A simpler but related instrument, the electroscope, works on similar principles but only indicates the relative magnitudes of voltages or charges. Historical electrometers Gold-leaf electroscope The gold-leaf electroscope was one of the instruments used to indicate electric charge. It is still used for science demonstrations but has been superseded in most applications by electronic measuring instruments. The instrument consists of two thin leaves of gold foil suspended from an electrode. When the electrode is charged by induction or by contact, the leaves acquire simi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field. When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb's law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a unit of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary School
A primary school (in Ireland, the United Kingdom, Australia, Trinidad and Tobago, Jamaica, and South Africa), junior school (in Australia), elementary school or grade school (in North America and the Philippines) is a school for primary education of children who are four to eleven years of age. Primary schooling follows pre-school and precedes secondary schooling. The International Standard Classification of Education considers primary education as a single phase where programmes are typically designed to provide fundamental skills in reading, writing, and mathematics and to establish a solid foundation for learning. This is International Standard Classification of Education#Level 1, ISCED Level 1: Primary education or first stage of basic education.Annex III in the ISCED 2011 English.pdf Na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swastika
The swastika (卐 or 卍) is an ancient religious and cultural symbol, predominantly in various Eurasian, as well as some African and American cultures, now also widely recognized for its appropriation by the Nazi Party and by neo-Nazis. It continues to be used as a symbol of divinity and spirituality in Indian religions, including Hinduism, Buddhism, and Jainism. It generally takes the form of a cross, the arms of which are of equal length and perpendicular to the adjacent arms, each bent midway at a right angle. The word ''swastika'' comes from sa, स्वस्तिक, svastika, meaning "conducive to well-being". In Hinduism, the right-facing symbol (clockwise) () is called ', symbolizing ("sun"), prosperity and good luck, while the left-facing symbol (counter-clockwise) () is called ''sauwastika'', symbolising night or tantric aspects of Kali. In Jain symbolism, it represents Suparshvanathathe seventh of 24 Tirthankaras (spiritual teachers and savio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Gordon (inventor)
Andrew Gordon (15 June 1712 - 22 August 1751) was a Scottish Benedictine monk, physicist and inventor. He made the first electric motor. Life Andrew Gordon was born in Cofforach, Forfarshire. He was a son of an old Scottish aristocratic family and baptized with the name George. At the age of 12, he travelled to Regensburg, Bavaria, in order to study at the Benedictine Scottish Monastery. As a Catholic Scot, there was no possibility of getting entrance to higher offices in his homeland. In Regensburg, he completed a 5-year general education course of study. Abbott Bernhard Baillie made it possible for Gordon to make education journeys to Austria, France and Italy, in particular to Rome. Gordon returned to Regensburg in 1732. On 24 February 1732 he enrolled as a novice and received the name of "Andreas". In the monastery he began with the study of scholastic philosophy under Gallus Leith, who in 1735 at the Erfurter university was appointed as a Professor for Philosophy. Gordon stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Age Of Enlightenment
The Age of Enlightenment or the Enlightenment; german: Aufklärung, "Enlightenment"; it, L'Illuminismo, "Enlightenment"; pl, Oświecenie, "Enlightenment"; pt, Iluminismo, "Enlightenment"; es, La Ilustración, "Enlightenment" was an intellectual and philosophical movement that dominated Europe in the 17th and 18th centuries with global influences and effects. The Enlightenment included a range of ideas centered on the value of human happiness, the pursuit of knowledge obtained by means of reason and the evidence of the senses, and ideals such as liberty, progress, toleration, fraternity, and constitutional government. The Enlightenment was preceded by the Scientific Revolution and the work of Francis Bacon, John Locke, and others. Some date the beginning of the Enlightenment to the publication of René Descartes' ''Discourse on the Method'' in 1637, featuring his famous dictum, ''Cogito, ergo sum'' ("I think, therefore I am"). Others cite the publication of Isaac Newto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Conductor
In physics and electrical engineering, a conductor is an object or type of material that allows the flow of charge (electric current) in one or more directions. Materials made of metal are common electrical conductors. Electric current is generated by the flow of negatively charged electrons, positively charged holes, and positive or negative ions in some cases. In order for current to flow within a closed electrical circuit, it is not necessary for one charged particle to travel from the component producing the current (the current source) to those consuming it (the loads). Instead, the charged particle simply needs to nudge its neighbor a finite amount, who will nudge ''its'' neighbor, and on and on until a particle is nudged into the consumer, thus powering it. Essentially what is occurring is a long chain of momentum transfer between mobile charge carriers; the Drude model of conduction describes this process more rigorously. This momentum transfer model makes metal an i ... [...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] |
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