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Corpuscle
Corpuscle () or corpuscule, meaning a "small body", is often used as a synonym for particle. It may also refer to: * Corpuscularianism, the atomistic view that all physical objects are composed of corpuscles, which was dominant among 17th century European thinkers * The corpuscular theory of light, developed by Isaac Newton in his ''Opticks'', which proposed the existence of light particles which are now known as photons * A term used by J. J. Thomson to describe particles now known to be electrons, in his plum pudding model * A small free-floating biological cell, especially a blood cell * A nerve ending such as Meissner's corpuscle or a Pacinian corpuscle * A colloquial nickname for students at Corpus Christi College, Cambridge and/or Corpus Christi College, Oxford Corpus Christi College (formally, Corpus Christi College in the University of Oxford; informally abbreviated as Corpus or CCC) is one of the constituent colleges of the University of Oxford in the United Kingdom. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pacinian Corpuscle
Pacinian corpuscle or lamellar corpuscle or Vater-Pacini corpuscle; is one of the four major types of mechanoreceptors (specialized nerve ending with adventitious tissue for mechanical sensation) found in mammalian skin. This type of mechanoreceptor is found in both glabrous (hairless) and hirsute (hairy) skins, viscera, joints and attached to periosteum of bone, primarily responsible for sensitivity to vibration. Few of them are also sensitive to quasi-static or low frequency pressure stimulus. Most of them respond only to sudden disturbances and are especially sensitive to vibration of few hundreds of Hz. The vibrational role may be used for detecting surface texture, e.g., rough vs. smooth. Most of the Pacinian corpuscles act as rapidly adapting mechanoreceptors. Groups of corpuscles respond to pressure changes, e.g. on grasping or releasing an object. Structure Pacinian corpuscles are larger and fewer in number than Meissner's corpuscle, Merkel cells and Ruffini's corpuscl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meissner's Corpuscle
Tactile corpuscles or Meissner's corpuscles are a type of mechanoreceptor discovered by anatomist Georg Meissner (1829–1905) and Rudolf Wagner. This corpuscle is a type of nerve ending in the skin that is responsible for sensitivity to pressure. In particular, they have their highest sensitivity (lowest threshold) when sensing vibrations between 10 and 50 hertz. They are rapidly adaptive receptors. They are most concentrated in thick hairless skin, especially at the finger pads. Structure Tactile corpuscles are encapsulated myelinated nerve endings, surrounded by Schwann cells. The encapsulation consists of flattened supportive cells arranged as horizontal lamellae surrounded by a connective tissue capsule. The corpuscle is 30–140 μm in length and 40–60 μm in diameter. A single nerve fiber meanders between the lamellae and throughout the corpuscle. Location They are distributed on various areas of the skin, but concentrated in areas especially sensitive to light ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plum Pudding Model
The plum pudding model is one of several historical scientific models of the atom. First proposed by J. J. Thomson in 1904 soon after the discovery of the electron, but before the discovery of the atomic nucleus, the model tried to explain two properties of atoms then known: that electrons are negatively charged particles and that atoms have no net electric charge. The plum pudding model has electrons surrounded by a volume of positive charge, like negatively charged "plums" embedded in a positively charged "pudding". Overview It had been known for many years that atoms contain negatively charged subatomic particles. Thomson called them "corpuscles" (particles), but they were more commonly called "electrons", the name G. J. Stoney had coined for the " fundamental unit quantity of electricity" in 1891. It had also been known for many years that atoms have no net electric charge. Thomson held that atoms must also contain some positive charge that cancels out the negative charge of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corpuscular Theory Of Light
In optics, the corpuscular theory of light states that light is made up of small discrete particles called " corpuscles" (little particles) which travel in a straight line with a finite velocity and possess impetus. This was based on an alternate description of atomism of the time period. Isaac Newton laid the foundations for this theory through his work in optics. This early conception of the particle theory of light was an early forerunner to the modern understanding of the photon. This theory came to dominate the conceptions of light in the eighteenth century, displacing the previously prominent vibration theories, where light was viewed as 'pressure' of the medium between the source and the receiver, first championed by René Descartes, and later in a more refined form by Christiaan Huygens. It would fall out of the spotlight in the early nineteenth century, as the wave theory of light amassed new experimental evidence. Mechanical philosophy In the early 17th century, natur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corpus Christi College, Cambridge
Corpus Christi College (full name: "The College of Corpus Christi and the Blessed Virgin Mary", often shortened to "Corpus"), is a constituent college of the University of Cambridge. From the late 14th century through to the early 19th century it was also commonly known as St Benet's College. The college is notable as the only one founded by Cambridge townspeople: it was established in 1352 by the Guild of Corpus Christi and the Guild of the Blessed Virgin Mary, making it the sixth-oldest college in Cambridge. With around 250 undergraduates and 200 postgraduates, it also has the second smallest student body of the traditional colleges of the University, after Peterhouse. The College has traditionally been one of the more academically successful colleges in the University of Cambridge. In the unofficial Tompkins Table, which ranks the colleges by the class of degrees obtained by their undergraduates, in 2012 Corpus was in third position, with 32.4% of its undergraduates achievi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Body
In common usage and classical mechanics, a physical object or physical body (or simply an object or body) is a collection of matter within a defined contiguous boundary in three-dimensional space. The boundary must be defined and identified by the properties of the material. The boundary may change over time. The boundary is usually the visible or tangible surface of the object. The matter in the object is constrained (to a greater or lesser degree) to move as one object. The boundary may move in space relative to other objects that it is not attached to (through translation and rotation). An object's boundary may also deform and change over time in other ways. Also in common usage, an object is not constrained to consist of the same collection of matter. Atoms or parts of an object may change over time. An object usually meant to be defined by the simplest representation of the boundary consistent with the observations. However the laws of physics only apply directly to objects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle
In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized physical body, object which can be described by several physical property, physical or chemical property, chemical properties, such as volume, density, or mass. They vary greatly in size or quantity, from subatomic particles like the electron, to microscopic scale, microscopic particles like atoms and molecules, to macroscopic scale, macroscopic particles like powder (substance), powders and other granular materials. Particles can also be used to create scientific models of even larger objects depending on their density, such as humans moving in a crowd or celestial bodies in motion (physics), motion. The term ''particle'' is rather general in meaning, and is refined as needed by various scientific fields. Anything that is composed of particles may be referred to as being particulate. However, the noun ''particulates, particulate'' is most frequently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corpuscularianism
Corpuscularianism (from the Latin ''corpusculum'' meaning "little body") is a set of theories that explain natural transformations as a result of the interaction of particles (''minima naturalia, partes exiles, partes parvae, particulae'', and ''semina''). It differs from atomism in that corpuscles are usually endowed with a property of their own and are further divisible, while atoms are neither. Although often associated with the emergence of early modern mechanical philosophy, and especially with the names of Thomas Hobbes,Kenneth Clatterbaugh, ''The Causation Debate in Modern Philosophy, 1637-1739'', Routledge, 2014, p. 69. René Descartes, Pierre Gassendi, Vere Claiborne Chappell (ed.), ''The Cambridge Companion to Locke'', Cambridge University Press, 1994, p. 56. Robert Boyle, Isaac Newton,virginia.edu [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opticks
''Opticks: or, A Treatise of the Reflexions, Refractions, Inflexions and Colours of Light'' is a book by English natural philosopher Isaac Newton that was published in English in 1704 (a scholarly Latin translation appeared in 1706). (''Opticks'' was originally published in 1704). The book analyzes the fundamental nature of light by means of the refraction of light with prisms and lenses, the diffraction of light by closely spaced sheets of glass, and the behaviour of color mixtures with spectral lights or pigment powders. ''Opticks'' was Newton's second major book on physical science and it is considered one of the three major works on optics during the Scientific Revolution (alongside Kepler's ''Astronomiae Pars Optica'' and Huygens' ''Traité de la Lumière''). Newton's name did not appear on the title page of the first edition of ''Opticks''. Overview The publication of ''Opticks'' represented a major contribution to science, different from but in some ways rivalling the ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always move at the speed of light in vacuum, (or about ). The photon belongs to the class of bosons. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, Planck proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explain the photoelectric effect, Eins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrons
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Cell
A blood cell, also called a hematopoietic cell, hemocyte, or hematocyte, is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Together, these three kinds of blood cells add up to a total 45% of the blood tissue by volume, with the remaining 55% of the volume composed of plasma, the liquid component of blood. Red blood cells Red blood cells or ''erythrocytes'', primarily carry oxygen and collect carbon dioxide through the use of hemoglobin. Hemoglobin is an iron-containing protein that gives red blood cells their color and facilitates transportation of oxygen from the lungs to tissues and carbon dioxide from tissues to the lungs to be exhaled. Red blood cells are the most abundant cell in the blood, accounting for about 40-45% of its volume. Red blood cells are circular, biconcave, disk-shaped and deformable to allow them to squee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
