1.
Maurice Quentin de La Tour
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Maurice Quentin de La Tour was a French Rococo portraitist who worked primarily with pastels. Among his most famous subjects were Voltaire, Rousseau, Louis XV and Madame de Pompadour. He was born in Saint-Quentin, Aisne, the son of a musician, François de La Tour, a Laonnois. François de La Tour apparently was successively a trumpet-player for the regiment of the duc du Maine. He is popularly said to have disapproved of his son taking up the arts, according to François Marandet in 2002, an apprenticeship was arranged for La Tour with a painter named Dupouch from 12 October 1719, but it is not known when this contract was terminated. After travelling briefly to England in 1725, he returned to Paris in 1727 and his earliest known portrait, of which only an engraving by Langlois of 1731 is testament, was that of Voltaire. Nevertheless, the painter Joseph Ducreux claimed to be his only student, on 25 May 1737 La Tour was officially recognised by the Royal Academy of Painting and Sculpture, and soon attracted the attention of the French court. According to Jeffares, he had an apartment in the palais du Louvre in 1745, contemporary accounts describe Quentin de La Tours nature as lively, good-humoured, but eccentric. However, of a nervous disposition, and an exacting practitioner, he has also been accused of over-engineering his work. He was also advisor and benefactor to the Royal Academy of Painting and Sculpture in Paris, jean-François de La Tour, chevalier de lordre royal militaire de Saint-Louis, was the natural heir to his estate. Issue of regular 50 Francs French Banknotes during the years 1976 to 1992 with de La Tours portrait, mariette et autres notes inédites de cet amateur sur les arts et les artistes. III, 1854–56, pp. 66–78. de Goncourt, Edmond and Jules
2.
University of Paris
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The University of Paris, metonymically known as the Sorbonne, was a university in Paris, France. Emerging around 1150 as an associated with the cathedral school of Notre Dame de Paris. Vast numbers of popes, royalties, scientists and intellectuals were educated at the University of Paris, following the turbulence of the French Revolution, education was suspended in 1793 whereafter its faculties were partly reorganised by Napoleon as the University of France. In 1896, it was renamed again to the University of Paris, in 1970, following the May 1968 events, the university was divided into 13 autonomous universities. Others, like Panthéon-Sorbonne University, chose to be multidisciplinary, in 1150, the future University of Paris was a student-teacher corporation operating as an annex of the Notre-Dame cathedral school. The university had four faculties, Arts, Medicine, Law, the Faculty of Arts was the lowest in rank, but also the largest, as students had to graduate there in order to be admitted to one of the higher faculties. The students were divided into four nationes according to language or regional origin, France, Normandy, Picardy, the last came to be known as the Alemannian nation. Recruitment to each nation was wider than the names might imply, the faculty and nation system of the University of Paris became the model for all later medieval universities. Under the governance of the Church, students wore robes and shaved the tops of their heads in tonsure, students followed the rules and laws of the Church and were not subject to the kings laws or courts. This presented problems for the city of Paris, as students ran wild, students were often very young, entering the school at age 13 or 14 and staying for 6 to 12 years. Three schools were especially famous in Paris, the palatine or palace school, the school of Notre-Dame, the decline of royalty brought about the decline of the first. The other two were ancient but did not have much visibility in the early centuries, the glory of the palatine school doubtless eclipsed theirs, until it completely gave way to them. These two centres were much frequented and many of their masters were esteemed for their learning, the first renowned professor at the school of Ste-Geneviève was Hubold, who lived in the tenth century. Not content with the courses at Liège, he continued his studies at Paris, entered or allied himself with the chapter of Ste-Geneviève, and attracted many pupils via his teaching. Distinguished professors from the school of Notre-Dame in the century include Lambert, disciple of Fulbert of Chartres, Drogo of Paris, Manegold of Germany. Three other men who added prestige to the schools of Notre-Dame and Ste-Geneviève were William of Champeaux, Abélard, humanistic instruction comprised grammar, rhetoric, dialectics, arithmetic, geometry, music, and astronomy. To the higher instruction belonged dogmatic and moral theology, whose source was the Scriptures and it was completed by the study of Canon law. The School of Saint-Victor arose to rival those of Notre-Dame and Ste-Geneviève and it was founded by William of Champeaux when he withdrew to the Abbey of Saint-Victor
3.
Ratio test
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In mathematics, the ratio test is a test for the convergence of a series ∑ n =1 ∞ a n, where each term is a real or complex number and an is nonzero when n is large. The test was first published by Jean le Rond dAlembert and is known as dAlemberts ratio test or as the Cauchy ratio test. The sum of the first m terms is given by,1 −12 m, as m increases, this converges to 1, so the sum of the series is 1. On the other hand given this geometric series, ∑ n =1 ∞2 n =2 +4 +8 + ⋯ The quotient a n +1 a n of any two adjacent terms is 2. The sum of the first m terms is given by 2 m +1 −2, more generally, the sum of the first m terms of the geometric series is given by, ∑ n =1 m r n = r r m −1 r −1. Whether this converges or diverges as m increases depends on whether r, however, as n increases, the ratio still tends in the limit towards the same constant 1/2. The ratio test generalizes the simple test for geometric series to more complex series like this one where the quotient of two terms is not fixed, but in the limit tends towards a fixed value. The rules are similar, if the quotient approaches a value less than one, the series converges, whereas if it approaches a value greater than one, the series diverges. It is possible to make the ratio test applicable to cases where the limit L fails to exist, if limit superior. The test criteria can also be refined so that the test is sometimes even when L =1. More specifically, let R = lim sup | a n +1 a n | r = lim inf | a n +1 a n |, if the limit L in exists, we must have L = R = r. So the original ratio test is a version of the refined one. As every term is positive, the series converges, consider the series ∑ n =1 ∞ e n n. Putting this into the ratio test, L = lim n → ∞ | a n +1 a n | = lim n → ∞ | e n +1 n +1 e n n | = e >1. Consider the three series ∑ n =1 ∞1, ∑ n =1 ∞1 n 2, ∑ n =1 ∞ n 1 n, the first series diverges, the second one converges absolutely and the third one converges conditionally. However, the term-by-term magnitude ratios | a n +1 a n | of the three series are respectively 1, n 22 and n n +1. So, in all three cases, we have lim n → ∞ | a n +1 a n | =1 and this illustrates that when L=1, the series may converge or diverge and hence the original ratio test is inconclusive. Below is a proof of the validity of the ratio test
4.
D'Alembert force
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The force F does not arise from any physical interaction between two objects, but rather from the acceleration a of the non-inertial reference frame itself. As stated by Iro, Such an additional force due to relative motion of two reference frames is called a pseudo-force. Assuming Newtons second law in the form F = ma, fictitious forces are proportional to the mass m. A fictitious force on an object arises when the frame of reference used to describe the motion is accelerating compared to a non-accelerating frame. As a frame can accelerate in any way, so can fictitious forces be as arbitrary. Gravitational force would also be a force based upon a field model in which particles distort spacetime due to their mass. The role of forces in Newtonian mechanics is described by Tonnelat. To solve classical mechanics problems exactly in an Earth-bound reference frame, the Euler force is typically ignored because the variations in the angular velocity of the rotating Earth surface are usually insignificant. Both of the fictitious forces are weak compared to most typical forces in everyday life. For example, Léon Foucault was able to show that the Coriolis force results from the Earths rotation using the Foucault pendulum. If the Earth were to rotate a thousand times faster, people could easily get the impression that such forces are pulling on them. Other accelerations also give rise to forces, as described mathematically below. An example of the detection of a non-inertial, rotating reference frame is the precession of a Foucault pendulum, in the non-inertial frame of the Earth, the fictitious Coriolis force is necessary to explain observations. In an inertial frame outside the Earth, no such force is necessary. Figure 1 shows an accelerating car, when a car accelerates, a passenger feels like theyre being pushed back into the seat. In an inertial frame of reference attached to the road, there is no physical force moving the rider backward, however, in the riders non-inertial reference frame attached to the accelerating car, there is a backward fictitious force. We mention two possible reasons for the force to clarify its existence, Figure 1, to an observer at rest on an inertial reference frame, the car will seem to accelerate. In order for the passenger to stay inside the car, a force must be exerted on the passenger
5.
Virtual work
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Virtual work arises in the application of the principle of least action to the study of forces and movement of a mechanical system. The work of a force acting on a particle as it moves along a displacement will be different for different displacements, among all the possible displacements that a particle may follow, called virtual displacements, one will minimize the action. This displacement is therefore the displacement followed by the according to the principle of least action. The work of a force on a particle along a displacement is known as the virtual work. The principle of work had always been used in some form since antiquity in the study of statics. It was used by the Greeks, medieval Arabs and Latins, working with Leibnizian concepts, Johann Bernoulli systematized the virtual work principle and made explicit the concept of infinitesimal displacement. He was able to solve problems for both bodies as well as fluids. Bernoullis version of virtual work law appeared in his letter to Pierre Varignon in 1715 and this formulation of the principle is today known as the principle of virtual velocities and is commonly considered as the prototype of the contemporary virtual work principles. In 1743 DAlembert published his Traite de Dynamique where he applied the principle of work, based on the Bernoullis work. His idea was to convert a dynamical problem into static problem by introducing inertial force, consider a point particle that moves along a path which is described by a function r from point A, where r, to point B, where r. It is possible that the moves from A to B along a nearby path described by r + δr. The variation δr satisfies the requirement δr = δr =0, the components of the variation, δr1, δr2 and δr3, are called virtual displacements. This can be generalized to a mechanical system defined by the generalized coordinates qi. In which case, the variation of the qi is defined by the virtual displacements δqi. Virtual work is the work done by the applied forces. When considering forces applied to a body in equilibrium, the principle of least action requires the virtual work of these forces to be zero. Consider a particle P that moves from a point A to a point B along a trajectory r and it is important to notice that the value of the work W depends on the trajectory r. Suppose the force F is the same as F, the variation of the work δW associated with this nearby path, known as the virtual work, can be computed to be δ W = W ¯ − W = ∫ t 0 t 1 d t
6.
D'Alembert equation
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The wave equation is an important second-order linear partial differential equation for the description of waves—as they occur in physics—such as sound waves, light waves and water waves. It arises in fields like acoustics, electromagnetics, and fluid dynamics, historically, the problem of a vibrating string such as that of a musical instrument was studied by Jean le Rond dAlembert, Leonhard Euler, Daniel Bernoulli, and Joseph-Louis Lagrange. In 1746, d’Alembert discovered the wave equation, and within ten years Euler discovered the three-dimensional wave equation. The wave equation is a partial differential equation. It typically concerns a time t, one or more spatial variables x1, x2, …, xn, and a scalar function u = u, whose values could model, for example. The wave equation for u is ∂2 u ∂ t 2 = c 2 ∇2 u where ∇2 is the Laplacian, therefore, the sum of any two solutions is again a solution, in physics this property is called the superposition principle. The wave equation, and modifications of it, are found in elasticity, quantum mechanics, plasma physics. The wave equation in one dimension can be written as follows. This equation is described as having only one space dimension x. The wave equation in one dimension can be derived in a variety of different physical settings. Most famously, it can be derived for the case of a string that is vibrating in a two-dimensional plane, another physical setting for derivation of the wave equation in one space dimension utilizes Hookes Law. The wave equation in the case can be derived from Hookes Law in the following way. In the case of a stress pulse propagating through a beam the beam acts much like a number of springs in series. A beam of constant cross section made from an elastic material has a stiffness K given by K = E A L Where A is the cross sectional area. Traveling means that the shape of these individual arbitrary functions with respect to x stays constant, however the functions are translated left and this was derived by Jean le Rond dAlembert. However, the waveforms F and G may also be generalized functions, in that case, the solution may be interpreted as an impulse that travels to the right or the left. The basic wave equation is a differential equation and so it will adhere to the superposition principle. This means that the net displacement caused by two or more waves is the sum of the displacements which would have been caused by each wave individually
7.
D'Alembert's equation
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The wave equation is an important second-order linear partial differential equation for the description of waves—as they occur in physics—such as sound waves, light waves and water waves. It arises in fields like acoustics, electromagnetics, and fluid dynamics, historically, the problem of a vibrating string such as that of a musical instrument was studied by Jean le Rond dAlembert, Leonhard Euler, Daniel Bernoulli, and Joseph-Louis Lagrange. In 1746, d’Alembert discovered the wave equation, and within ten years Euler discovered the three-dimensional wave equation. The wave equation is a partial differential equation. It typically concerns a time t, one or more spatial variables x1, x2, …, xn, and a scalar function u = u, whose values could model, for example. The wave equation for u is ∂2 u ∂ t 2 = c 2 ∇2 u where ∇2 is the Laplacian, therefore, the sum of any two solutions is again a solution, in physics this property is called the superposition principle. The wave equation, and modifications of it, are found in elasticity, quantum mechanics, plasma physics. The wave equation in one dimension can be written as follows. This equation is described as having only one space dimension x. The wave equation in one dimension can be derived in a variety of different physical settings. Most famously, it can be derived for the case of a string that is vibrating in a two-dimensional plane, another physical setting for derivation of the wave equation in one space dimension utilizes Hookes Law. The wave equation in the case can be derived from Hookes Law in the following way. In the case of a stress pulse propagating through a beam the beam acts much like a number of springs in series. A beam of constant cross section made from an elastic material has a stiffness K given by K = E A L Where A is the cross sectional area. Traveling means that the shape of these individual arbitrary functions with respect to x stays constant, however the functions are translated left and this was derived by Jean le Rond dAlembert. However, the waveforms F and G may also be generalized functions, in that case, the solution may be interpreted as an impulse that travels to the right or the left. The basic wave equation is a differential equation and so it will adhere to the superposition principle. This means that the net displacement caused by two or more waves is the sum of the displacements which would have been caused by each wave individually
8.
D'Alembert's paradox
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In fluid dynamics, dAlemberts paradox is a contradiction reached in 1752 by French mathematician Jean le Rond dAlembert. DAlembert proved that – for incompressible and inviscid potential flow – the drag force is zero on a body moving with constant velocity relative to the fluid and it is a particular example of the reversibility paradox. A physical paradox indicates flaws in the theory, according to scientific consensus, the occurrence of the paradox is due to the neglected effects of viscosity. In conjunction with scientific experiments, there were advances in the theory of viscous fluid friction during the 19th century. With respect to the paradox, this culminated in the discovery, even at very high Reynolds numbers, the thin boundary layers remain as a result of viscous forces. These viscous forces cause friction drag on streamlined objects, and for bluff bodies the additional result is flow separation, the general view in the fluid mechanics community is that, from a practical point of view, the paradox is solved along the lines suggested by Prandtl. A formal mathematical proof is lacking, and difficult to provide, first steps towards solving the paradox were made by Saint-Venant, who modelled viscous fluid friction. Soon after, in 1851, Stokes calculated the drag on a sphere in Stokes flow, Stokes flow is the low Reynolds-number limit of the Navier–Stokes equations describing the motion of a viscous liquid. Of this, there is no evidence found in experimental measurements of drag and this again raised questions concerning the applicability of fluid mechanics in the second half of the 19th century. The model proposed by Kirchhoff and Rayleigh was based on the theory of Helmholtz. Assumptions applied to the region include, flow velocities equal to the body velocity. This wake region is separated from the potential flow outside the body, in order to have a non-zero drag on the body, the wake region must extend to infinity. This condition is indeed fulfilled for the Kirchhoff flow perpendicular to a plate, the theory correctly states the drag force to be proportional to the square of the velocity. In first instance, the theory could only be applied to flows separating at sharp edges, later, in 1907, it was extended by Levi-Civita to flows separating from a smooth curved boundary. It was readily known that such steady flows are not stable, but this steady-flow model was studied further in the hope it still could give a reasonable estimate of drag. This is mainly due to suction at the side of the plate. So, this theory is found to be unsatisfactory as an explanation of drag on a body moving through a fluid, although it can be applied to so-called cavity flows where, instead of a wake filled with fluid, a vacuum cavity is assumed to exist behind the body. The German physicist Ludwig Prandtl suggested in 1904 that the effects of a viscous boundary layer possibly could be the source of substantial drag
9.
D'Alembert's principle
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DAlemberts principle, also known as the Lagrange–dAlembert principle, is a statement of the fundamental classical laws of motion. It is named after its discoverer, the French physicist and mathematician Jean le Rond dAlembert and it is the dynamic analogue to the principle of virtual work for applied forces in a static system and in fact is more general than Hamiltons principle, avoiding restriction to holonomic systems. A holonomic constraint depends only on the coordinates and time and it does not depend on the velocities. The principle does not apply for irreversible displacements, such as sliding friction, DAlemberts contribution was to demonstrate that in the totality of a dynamic system the forces of constraint vanish. That is to say that the generalized forces Q j need not include constraint forces and it is equivalent to the somewhat more cumbersome Gausss principle of least constraint. The general statement of dAlemberts principle mentions the time derivatives of the momenta of the system. The momentum of the mass is the product of its mass and velocity, p i = m i v i. In many applications, the masses are constant and this reduces to p i ˙ = m i v ˙ i = m i a i. However, some applications involve changing masses and in those cases both terms m ˙ i v i and m i v ˙ i have to remain present, to date, nobody has shown that DAlemberts principle is equivalent to Newtons Second Law. This is true only for very special cases e. g. rigid body constraints. However, a solution to this problem does exist. Consider Newtons law for a system of particles, i, if arbitrary virtual displacements are assumed to be in directions that are orthogonal to the constraint forces, the constraint forces do no work. Such displacements are said to be consistent with the constraints and this leads to the formulation of dAlemberts principle, which states that the difference of applied forces and inertial forces for a dynamic system does no virtual work. There is also a principle for static systems called the principle of virtual work for applied forces. DAlembert showed that one can transform an accelerating rigid body into an equivalent static system by adding the so-called inertial force, the inertial force must act through the center of mass and the inertial torque can act anywhere. The system can then be analyzed exactly as a static system subjected to this force and moment. The advantage is that, in the equivalent static system one can take moments about any point and this often leads to simpler calculations because any force can be eliminated from the moment equations by choosing the appropriate point about which to apply the moment equation. Even in the course of Fundamentals of Dynamics and Kinematics of machines, in textbooks of engineering dynamics this is sometimes referred to as dAlemberts principle
10.
Figurative system of human knowledge
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The tree was a taxonomy of human knowledge, inspired by Francis Bacons The Advancement of Learning. The three main branches of knowledge in the tree are, Memory/History, Reason/Philosophy, and Imagination/Poetry, notable is the fact that theology is ordered under Philosophy. Additionally notice that Knowledge of God is only a few nodes away from Divination, the original version, in French, can be seen in the graphic on the right. An image of the diagram with English translations superimposed over the French text is available, another example of English translation of the tree is available in literature. Below is a version of it rendered in English as a bulleted outline, detailed System of Human Knowledge from the Encyclopédie. Of Meteors. of the Earth and the Sea of Minerals, Uses of Nature Arts, Crafts, Manufactures. Work and Uses of Gold and Silver, work and Uses of Precious Stones. Work and Uses of Stone, Plaster, Slate, etc, reason Philosophy General Metaphysics, or Ontology, or Science of Being in General, of Possibility, of Existence, of Duration, etc. Science of Good and Evil Spirits, pneumatology or Science of the Soul. Arts of Writing, Printing, Reading, Deciphering, art of Communication Science of the Instrument of Discourse. General Science of Good and Evil, of duties in general, of Virtue, of the necessity of being Virtuous, Science of Nature Metaphysics of Bodies or, General Physics, of Extent, of Impenetrability, of Movement, of Word, etc. Epic Poem Madrigal Epigram Novel, etc, the structure of knowledge, classifications of science and learning since the Renaissance. Adams, David The Système figuré des Connaissances humaines and the structure of Knowledge in the Encyclopédie, in Ordering the World, ed. Diana Donald and Frank OGorman, London, Macmillan, p. 190-215. Preliminary discourse to the Encyclopedia of Diderot, Jean Le Rond dAlembert, translated by Richard N. Schwab,1995
11.
Fluid dynamics
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In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids. It has several subdisciplines, including aerodynamics and hydrodynamics, before the twentieth century, hydrodynamics was synonymous with fluid dynamics. This is still reflected in names of some fluid dynamics topics, like magnetohydrodynamics and hydrodynamic stability, the foundational axioms of fluid dynamics are the conservation laws, specifically, conservation of mass, conservation of linear momentum, and conservation of energy. These are based on mechanics and are modified in quantum mechanics. They are expressed using the Reynolds transport theorem, in addition to the above, fluids are assumed to obey the continuum assumption. Fluids are composed of molecules that collide with one another and solid objects, however, the continuum assumption assumes that fluids are continuous, rather than discrete. The fact that the fluid is made up of molecules is ignored. The unsimplified equations do not have a general solution, so they are primarily of use in Computational Fluid Dynamics. The equations can be simplified in a number of ways, all of which make them easier to solve, some of the simplifications allow some simple fluid dynamics problems to be solved in closed form. Three conservation laws are used to solve fluid dynamics problems, the conservation laws may be applied to a region of the flow called a control volume. A control volume is a volume in space through which fluid is assumed to flow. The integral formulations of the laws are used to describe the change of mass, momentum. Mass continuity, The rate of change of fluid mass inside a control volume must be equal to the net rate of flow into the volume. Mass flow into the system is accounted as positive, and since the vector to the surface is opposite the sense of flow into the system the term is negated. The first term on the right is the net rate at which momentum is convected into the volume, the second term on the right is the force due to pressure on the volumes surfaces. The first two terms on the right are negated since momentum entering the system is accounted as positive, the third term on the right is the net acceleration of the mass within the volume due to any body forces. Surface forces, such as forces, are represented by F surf. The following is the form of the momentum conservation equation
12.
Three-body problem
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The three-body problem is a special case of the n-body problem. Historically, the first specific three-body problem to receive extended study was the one involving the Moon, the Earth, in an extended modern sense, a three-body problem is a class of problems in classical or quantum mechanics that model the motion of three particles. The gravitational problem of three bodies in its traditional sense dates in substance from 1687, when Isaac Newton published his Principia. The physical problem was addressed by Amerigo Vespucci and subsequently by Galileo Galilei, however the accuracy of the lunar theory was low, due to the perturbing effect of the Sun and planets on the motion of the Moon around the Earth. They submitted their competing first analyses to the Académie Royale des Sciences in 1747 and it was in connection with these researches, in Paris, in the 1740s, that the name three-body problem began to be commonly used. An account published in 1761 by Jean le Rond dAlembert indicates that the name was first used in 1747, in 1887, mathematicians Heinrich Bruns and Henri Poincaré showed that there is no general analytical solution for the three-body problem given by algebraic expressions and integrals. The motion of three bodies is generally non-repeating, except in special cases, a prominent example of the classical three-body problem is the movement of a planet with a satellite around a star. In this case, the problem is simplified to two instances of the two-body problem, however, the effect of the star on the movement of the satellite around the planet can be considered as a perturbation. While a spaceflight involving a gravity assist tends to be at least a problem, once far away from the Earth when Earths gravity becomes negligible. The general statement for the three body problem is as follows, in the circular restricted three-body problem, two massive bodies move in circular orbits around their common center of mass, and the third mass is negligible with respect to the other two. It can be useful to consider the effective potential, in 1767 Leonhard Euler found three families of periodic solutions in which the three masses are collinear at each instant. In 1772 Lagrange found a family of solutions in which the three form an equilateral triangle at each instant. Together, these form the central configurations for the three-body problem. These solutions are valid for any mass ratios, and the move on Keplerian ellipses. These five families are the only solutions for which there are explicit analytic formulae. In 1893 Meissel stated what is called the Pythagorean three-body problem. Burrau further investigated this problem in 1913, in 1967 Victor Szebehely and coworkers established eventual escape for this problem using numerical integration, while at the same time finding a nearby periodic solution. In 1911, United States scientist William Duncan MacMillan found one special solution, in 1961, Russian mathematician Sitnikov improved this solution
13.
Royal Society
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Founded in November 1660, it was granted a royal charter by King Charles II as The Royal Society. The society is governed by its Council, which is chaired by the Societys President, according to a set of statutes and standing orders. The members of Council and the President are elected from and by its Fellows, the members of the society. As of 2016, there are about 1,600 fellows, allowed to use the postnominal title FRS, there are also royal fellows, honorary fellows and foreign members, the last of which are allowed to use the postnominal title ForMemRS. The Royal Society President is Venkatraman Ramakrishnan, who took up the post on 30 November 2015, since 1967, the society has been based at 6–9 Carlton House Terrace, a Grade I listed building in central London which was previously used by the Embassy of Germany, London. The Royal Society started from groups of physicians and natural philosophers, meeting at variety of locations and they were influenced by the new science, as promoted by Francis Bacon in his New Atlantis, from approximately 1645 onwards. A group known as The Philosophical Society of Oxford was run under a set of rules still retained by the Bodleian Library, after the English Restoration, there were regular meetings at Gresham College. It is widely held that these groups were the inspiration for the foundation of the Royal Society, I will not say, that Mr Oldenburg did rather inspire the French to follow the English, or, at least, did help them, and hinder us. But tis well known who were the men that began and promoted that design. This initial royal favour has continued and, since then, every monarch has been the patron of the society, the societys early meetings included experiments performed first by Hooke and then by Denis Papin, who was appointed in 1684. These experiments varied in their area, and were both important in some cases and trivial in others. The Society returned to Gresham in 1673, there had been an attempt in 1667 to establish a permanent college for the society. Michael Hunter argues that this was influenced by Solomons House in Bacons New Atlantis and, to a lesser extent, by J. V. The first proposal was given by John Evelyn to Robert Boyle in a letter dated 3 September 1659, he suggested a scheme, with apartments for members. The societys ideas were simpler and only included residences for a handful of staff and these plans were progressing by November 1667, but never came to anything, given the lack of contributions from members and the unrealised—perhaps unrealistic—aspirations of the society. During the 18th century, the gusto that had characterised the early years of the society faded, with a number of scientific greats compared to other periods. The pointed lightning conductor had been invented by Benjamin Franklin in 1749, during the same time period, it became customary to appoint society fellows to serve on government committees where science was concerned, something that still continues. The 18th century featured remedies to many of the early problems
14.
Institut de France
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The Institut de France is a French learned society, grouping five académies, the most famous of which is the Académie française. The Institute, located in Paris, manages approximately 1,000 foundations, as well as museums and it also awards prizes and subsidies, which amounted to a total of €5,028,190.55 for 2002. Most of these prizes are awarded by the Institute on the recommendation of the académies, the Institut de France was established on 25 October 1795, by the French government. Académie française – initiated 1635, suppressed 1793, restored 1803 as a division of the institute, Académie des inscriptions et belles-lettres – initiated 1663. Académie des sciences – initiated 1666, the Royal Society of Canada, initiated 1882, was modeled after the Institut de France and the Royal Society of London
15.
Mathematics
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Mathematics is the study of topics such as quantity, structure, space, and change. There is a range of views among mathematicians and philosophers as to the exact scope, Mathematicians seek out patterns and use them to formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proof, when mathematical structures are good models of real phenomena, then mathematical reasoning can provide insight or predictions about nature. Through the use of abstraction and logic, mathematics developed from counting, calculation, measurement, practical mathematics has been a human activity from as far back as written records exist. The research required to solve mathematical problems can take years or even centuries of sustained inquiry, rigorous arguments first appeared in Greek mathematics, most notably in Euclids Elements. Galileo Galilei said, The universe cannot be read until we have learned the language and it is written in mathematical language, and the letters are triangles, circles and other geometrical figures, without which means it is humanly impossible to comprehend a single word. Without these, one is wandering about in a dark labyrinth, carl Friedrich Gauss referred to mathematics as the Queen of the Sciences. Benjamin Peirce called mathematics the science that draws necessary conclusions, David Hilbert said of mathematics, We are not speaking here of arbitrariness in any sense. Mathematics is not like a game whose tasks are determined by arbitrarily stipulated rules, rather, it is a conceptual system possessing internal necessity that can only be so and by no means otherwise. Albert Einstein stated that as far as the laws of mathematics refer to reality, they are not certain, Mathematics is essential in many fields, including natural science, engineering, medicine, finance and the social sciences. Applied mathematics has led to entirely new mathematical disciplines, such as statistics, Mathematicians also engage in pure mathematics, or mathematics for its own sake, without having any application in mind. There is no clear line separating pure and applied mathematics, the history of mathematics can be seen as an ever-increasing series of abstractions. The earliest uses of mathematics were in trading, land measurement, painting and weaving patterns, in Babylonian mathematics elementary arithmetic first appears in the archaeological record. Numeracy pre-dated writing and numeral systems have many and diverse. Between 600 and 300 BC the Ancient Greeks began a study of mathematics in its own right with Greek mathematics. Mathematics has since been extended, and there has been a fruitful interaction between mathematics and science, to the benefit of both. Mathematical discoveries continue to be made today, the overwhelming majority of works in this ocean contain new mathematical theorems and their proofs. The word máthēma is derived from μανθάνω, while the modern Greek equivalent is μαθαίνω, in Greece, the word for mathematics came to have the narrower and more technical meaning mathematical study even in Classical times
16.
Mechanics
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Mechanics is an area of science concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment. The scientific discipline has its origins in Ancient Greece with the writings of Aristotle, during the early modern period, scientists such as Khayaam, Galileo, Kepler, and Newton, laid the foundation for what is now known as classical mechanics. It is a branch of physics that deals with particles that are either at rest or are moving with velocities significantly less than the speed of light. It can also be defined as a branch of science which deals with the motion of, historically, classical mechanics came first, while quantum mechanics is a comparatively recent invention. Classical mechanics originated with Isaac Newtons laws of motion in Philosophiæ Naturalis Principia Mathematica, both are commonly held to constitute the most certain knowledge that exists about physical nature. Classical mechanics has especially often been viewed as a model for other so-called exact sciences, essential in this respect is the relentless use of mathematics in theories, as well as the decisive role played by experiment in generating and testing them. Quantum mechanics is of a scope, as it encompasses classical mechanics as a sub-discipline which applies under certain restricted circumstances. According to the principle, there is no contradiction or conflict between the two subjects, each simply pertains to specific situations. The correspondence principle states that the behavior of systems described by quantum theories reproduces classical physics in the limit of quantum numbers. Quantum mechanics has superseded classical mechanics at the level and is indispensable for the explanation and prediction of processes at the molecular, atomic. However, for macroscopic processes classical mechanics is able to solve problems which are difficult in quantum mechanics and hence remains useful. Modern descriptions of such behavior begin with a definition of such quantities as displacement, time, velocity, acceleration, mass. Until about 400 years ago, however, motion was explained from a different point of view. He showed that the speed of falling objects increases steadily during the time of their fall and this acceleration is the same for heavy objects as for light ones, provided air friction is discounted. The English mathematician and physicist Isaac Newton improved this analysis by defining force and mass, for objects traveling at speeds close to the speed of light, Newton’s laws were superseded by Albert Einstein’s theory of relativity. For atomic and subatomic particles, Newton’s laws were superseded by quantum theory, for everyday phenomena, however, Newton’s three laws of motion remain the cornerstone of dynamics, which is the study of what causes motion. In analogy to the distinction between quantum and classical mechanics, Einsteins general and special theories of relativity have expanded the scope of Newton, the differences between relativistic and Newtonian mechanics become significant and even dominant as the velocity of a massive body approaches the speed of light. Relativistic corrections are also needed for quantum mechanics, although general relativity has not been integrated, the two theories remain incompatible, a hurdle which must be overcome in developing a theory of everything
17.
Physics
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Physics is the natural science that involves the study of matter and its motion and behavior through space and time, along with related concepts such as energy and force. One of the most fundamental disciplines, the main goal of physics is to understand how the universe behaves. Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy, Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the mechanisms of other sciences while opening new avenues of research in areas such as mathematics. Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs, the United Nations named 2005 the World Year of Physics. Astronomy is the oldest of the natural sciences, the stars and planets were often a target of worship, believed to represent their gods. While the explanations for these phenomena were often unscientific and lacking in evidence, according to Asger Aaboe, the origins of Western astronomy can be found in Mesopotamia, and all Western efforts in the exact sciences are descended from late Babylonian astronomy. The most notable innovations were in the field of optics and vision, which came from the works of many scientists like Ibn Sahl, Al-Kindi, Ibn al-Haytham, Al-Farisi and Avicenna. The most notable work was The Book of Optics, written by Ibn Al-Haitham, in which he was not only the first to disprove the ancient Greek idea about vision, but also came up with a new theory. In the book, he was also the first to study the phenomenon of the pinhole camera, many later European scholars and fellow polymaths, from Robert Grosseteste and Leonardo da Vinci to René Descartes, Johannes Kepler and Isaac Newton, were in his debt. Indeed, the influence of Ibn al-Haythams Optics ranks alongside that of Newtons work of the same title, the translation of The Book of Optics had a huge impact on Europe. From it, later European scholars were able to build the devices as what Ibn al-Haytham did. From this, such important things as eyeglasses, magnifying glasses, telescopes, Physics became a separate science when early modern Europeans used experimental and quantitative methods to discover what are now considered to be the laws of physics. Newton also developed calculus, the study of change, which provided new mathematical methods for solving physical problems. The discovery of new laws in thermodynamics, chemistry, and electromagnetics resulted from greater research efforts during the Industrial Revolution as energy needs increased, however, inaccuracies in classical mechanics for very small objects and very high velocities led to the development of modern physics in the 20th century. Modern physics began in the early 20th century with the work of Max Planck in quantum theory, both of these theories came about due to inaccuracies in classical mechanics in certain situations. Quantum mechanics would come to be pioneered by Werner Heisenberg, Erwin Schrödinger, from this early work, and work in related fields, the Standard Model of particle physics was derived. Areas of mathematics in general are important to this field, such as the study of probabilities, in many ways, physics stems from ancient Greek philosophy
18.
Philosophy
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Philosophy is the study of general and fundamental problems concerning matters such as existence, knowledge, values, reason, mind, and language. The term was coined by Pythagoras. Philosophical methods include questioning, critical discussion, rational argument and systematic presentation, classic philosophical questions include, Is it possible to know anything and to prove it. However, philosophers might also pose more practical and concrete questions such as, is it better to be just or unjust. Historically, philosophy encompassed any body of knowledge, from the time of Ancient Greek philosopher Aristotle to the 19th century, natural philosophy encompassed astronomy, medicine and physics. For example, Newtons 1687 Mathematical Principles of Natural Philosophy later became classified as a book of physics, in the 19th century, the growth of modern research universities led academic philosophy and other disciplines to professionalize and specialize. In the modern era, some investigations that were part of philosophy became separate academic disciplines, including psychology, sociology. Other investigations closely related to art, science, politics, or other pursuits remained part of philosophy, for example, is beauty objective or subjective. Are there many scientific methods or just one, is political utopia a hopeful dream or hopeless fantasy. Major sub-fields of academic philosophy include metaphysics, epistemology, ethics, aesthetics, political philosophy, logic, philosophy of science, since the 20th century, professional philosophers contribute to society primarily as professors, researchers and writers. Traditionally, the term referred to any body of knowledge. In this sense, philosophy is related to religion, mathematics, natural science, education. This division is not obsolete but has changed, Natural philosophy has split into the various natural sciences, especially astronomy, physics, chemistry, biology and cosmology. Moral philosophy has birthed the social sciences, but still includes value theory, metaphysical philosophy has birthed formal sciences such as logic, mathematics and philosophy of science, but still includes epistemology, cosmology and others. Many philosophical debates that began in ancient times are still debated today, colin McGinn and others claim that no philosophical progress has occurred during that interval. Chalmers and others, by contrast, see progress in philosophy similar to that in science, in one general sense, philosophy is associated with wisdom, intellectual culture and a search for knowledge. In that sense, all cultures and literate societies ask philosophical questions such as how are we to live, a broad and impartial conception of philosophy then, finds a reasoned inquiry into such matters as reality, morality and life in all world civilizations. Socrates was an influential philosopher, who insisted that he possessed no wisdom but was a pursuer of wisdom
19.
Pierre-Simon Laplace
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Pierre-Simon, marquis de Laplace was an influential French scholar whose work was important to the development of mathematics, statistics, physics and astronomy. He summarized and extended the work of his predecessors in his five-volume Mécanique Céleste and this work translated the geometric study of classical mechanics to one based on calculus, opening up a broader range of problems. In statistics, the Bayesian interpretation of probability was developed mainly by Laplace, Laplace formulated Laplaces equation, and pioneered the Laplace transform which appears in many branches of mathematical physics, a field that he took a leading role in forming. The Laplacian differential operator, widely used in mathematics, is named after him. Laplace is remembered as one of the greatest scientists of all time, sometimes referred to as the French Newton or Newton of France, he has been described as possessing a phenomenal natural mathematical faculty superior to that of any of his contemporaries. Laplace became a count of the Empire in 1806 and was named a marquis in 1817, Laplace was born in Beaumont-en-Auge, Normandy on 23 March 1749, a village four miles west of Pont lEveque in Normandy. According to W. W. Rouse Ball, His father, Pierre de Laplace and his great-uncle, Maitre Oliver de Laplace, had held the title of Chirurgien Royal. It would seem that from a pupil he became an usher in the school at Beaumont, however, Karl Pearson is scathing about the inaccuracies in Rouse Balls account and states, Indeed Caen was probably in Laplaces day the most intellectually active of all the towns of Normandy. It was here that Laplace was educated and was provisionally a professor and it was here he wrote his first paper published in the Mélanges of the Royal Society of Turin, Tome iv. 1766–1769, at least two years before he went at 22 or 23 to Paris in 1771, thus before he was 20 he was in touch with Lagrange in Turin. He did not go to Paris a raw self-taught country lad with only a peasant background, the École Militaire of Beaumont did not replace the old school until 1776. His parents were from comfortable families and his father was Pierre Laplace, and his mother was Marie-Anne Sochon. The Laplace family was involved in agriculture until at least 1750, Pierre Simon Laplace attended a school in the village run at a Benedictine priory, his father intending that he be ordained in the Roman Catholic Church. At sixteen, to further his fathers intention, he was sent to the University of Caen to read theology, at the university, he was mentored by two enthusiastic teachers of mathematics, Christophe Gadbled and Pierre Le Canu, who awoke his zeal for the subject. Here Laplaces brilliance as a mathematician was recognised and while still at Caen he wrote a memoir Sur le Calcul integral aux differences infiniment petites et aux differences finies. About this time, recognizing that he had no vocation for the priesthood, in this connection reference may perhaps be made to the statement, which has appeared in some notices of him, that he broke altogether with the church and became an atheist. Laplace did not graduate in theology but left for Paris with a letter of introduction from Le Canu to Jean le Rond dAlembert who at time was supreme in scientific circles. According to his great-great-grandson, dAlembert received him rather poorly, and to get rid of him gave him a mathematics book
20.
Physicist
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A physicist is a scientist who has specialized knowledge in the field of physics, the exploration of the interactions of matter and energy across the physical universe. A physicist is a scientist who specializes or works in the field of physics, physicists generally are interested in the root or ultimate causes of phenomena, and usually frame their understanding in mathematical terms. Physicists can also apply their knowledge towards solving real-world problems or developing new technologies, some physicists specialize in sectors outside the science of physics itself, such as engineering. The study and practice of physics is based on a ladder of discoveries. Many mathematical and physical ideas used today found their earliest expression in ancient Greek culture and Asian culture, the bulk of physics education can be said to flow from the scientific revolution in Europe, starting with the work of Galileo and Kepler in the early 1600s. New knowledge in the early 21st century includes an increase in understanding physical cosmology. The term physicist was coined by William Whewell in his 1840 book The Philosophy of the Inductive Sciences, many physicist positions require an undergraduate degree in applied physics or a related science or a Masters degree like MSc, MPhil, MPhys or MSci. In a research oriented level, students tend to specialize in a particular field, Physics students also need training in mathematics, and also in computer science and programming. For being employed as a physicist a doctoral background may be required for certain positions, undergraduate students like BSc Mechanical Engineering, BSc Electrical and Computer Engineering, BSc Applied Physics. etc. With physics orientation are chosen as research assistants with faculty members, the highest honor awarded to physicists is the Nobel Prize in Physics, awarded since 1901 by the Royal Swedish Academy of Sciences. The three major employers of career physicists are academic institutions, laboratories, and private industries, with the largest employer being the last, physicists in academia or government labs tend to have titles such as Assistants, Professors, Sr. /Jr. As per the American Institute for Physics, some 20% of new physics Ph. D. s holds jobs in engineering development programs, while 14% turn to computer software, a majority of physicists employed apply their skills and training to interdisciplinary sectors. For industry or self-employment. and also in science and programming. Hence a majority of Physics bachelors degree holders are employed in the private sector, other fields are academia, government and military service, nonprofit entities, labs and teaching
21.
Music theory
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Music theory is the study of the practices and possibilities of music. The term is used in three ways in music, though all three are interrelated. The first is what is otherwise called rudiments, currently taught as the elements of notation, of key signatures, of time signatures, of rhythmic notation, Theory in this sense is treated as the necessary preliminary to the study of harmony, counterpoint, and form. The second is the study of writings about music from ancient times onwards, Music theory is frequently concerned with describing how musicians and composers make music, including tuning systems and composition methods among other topics. However, this medieval discipline became the basis for tuning systems in later centuries, Music theory as a practical discipline encompasses the methods and concepts composers and other musicians use in creating music. The development, preservation, and transmission of music theory in this sense may be found in oral and written music-making traditions, musical instruments, and other artifacts. In ancient and living cultures around the world, the deep and long roots of music theory are clearly visible in instruments, oral traditions, and current music making. Many cultures, at least as far back as ancient Mesopotamia and ancient China, have also considered music theory in more formal ways such as written treatises, in modern academia, music theory is a subfield of musicology, the wider study of musical cultures and history. Etymologically, music theory is an act of contemplation of music, from the Greek θεωρία, a looking at, viewing, contemplation, speculation, theory, also a sight, a person who researches, teaches, or writes articles about music theory is a music theorist. University study, typically to the M. A. or Ph. D level, is required to teach as a music theorist in a US or Canadian university. Methods of analysis include mathematics, graphic analysis, and especially analysis enabled by Western music notation, comparative, descriptive, statistical, and other methods are also used. See for instance Paleolithic flutes, Gǔdí, and Anasazi flute, several surviving Sumerian and Akkadian clay tablets include musical information of a theoretical nature, mainly lists of intervals and tunings. The scholar Sam Mirelman reports that the earliest of these dates from before 1500 BCE. Further, All the Mesopotamian texts are united by the use of a terminology for music that, much of Chinese music history and theory remains unclear. The earliest texts about Chinese music theory are inscribed on the stone and they include more than 2800 words describing theories and practices of music pitches of the time. The bells produce two intertwined pentatonic scales three tones apart with additional pitches completing the chromatic scale, Chinese theory starts from numbers, the main musical numbers being twelve, five and eight. Twelve refers to the number of pitches on which the scales can be constructed, the Lüshi chunqiu from about 239 BCE recalls the legend of Ling Lun. On order of the Yellow Emperor, Ling Lun collected twelve bamboo lengths with thick, blowing on one of these like a pipe, he found its sound agreeable and named it huangzhong, the Yellow Bell
22.
Denis Diderot
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Denis Diderot was a French philosopher, art critic, and writer. He was a prominent figure during the Enlightenment and is best known for serving as co-founder, chief editor, Denis Diderot was born in Langres, Champagne, and began his formal education at a Jesuit collège in Langres. His parents were Didier Diderot a cutler, maître coutelier, three of five siblings survived to adulthood, Denise Diderot and their youngest brother Pierre-Didier Diderot, and finally their sister Angélique Diderot. According to Arthur McCandless Wilson, Denis Diderot greatly admired his sister Denise, in 1732 Denis Diderot earned the Master of Arts degree in philosophy. Then he entered the Collège dHarcourt of the University of Paris and he abandoned the idea of entering the clergy and decided instead to study at the Paris Law Faculty. His study of law was short-lived however and in 1734 Diderot decided to become a writer, because of his refusal to enter one of the learned professions, he was disowned by his father, and for the next ten years he lived a bohemian existence. In 1742 he befriended Jean-Jacques Rousseau, in 1743 he further alienated his father by marrying Antoinette Champion, a devout Roman Catholic. The match was considered due to Champions low social standing, poor education, fatherless status. She was about three years older than Diderot, the marriage in October 1743 produced one surviving child, a girl. Her name was Angélique, after both Diderots dead mother and sister, the death of his sister, a nun, from overwork in the convent may have affected Diderots opinion of religion. Babuti, Madeleine de Puisieux, Sophie Volland and Mme de Maux and his letters to Sophie Volland are known for their candor and are regarded to be among the literary treasures of the eighteenth century. Though his work was broad as well as rigorous, it did not bring Diderot riches, when the time came for him to provide a dowry for his daughter, he saw no alternative than to sell his library. When Empress Catherine II of Russia heard of his financial troubles she commissioned an agent in Paris to buy the library and she then requested that the philosopher retain the books in Paris until she required them, and act as her librarian with a yearly salary. Between October 1773 and March 1774, the sick Diderot spent a few months at the court in Saint Petersburg. Diderot died of thrombosis in Paris on 31 July 1784. His heirs sent his vast library to Catherine II, who had it deposited at the National Library of Russia and this idea seems to have been shelved. In 1745, he published a translation of Shaftesburys Inquiry Concerning Virtue and Merit, in 1746, Diderot wrote his first original work, the Philosophical Thoughts. In this book, Diderot argued for a reconciliation of reason with feeling so as to establish harmony, according to Diderot, without feeling there would be a detrimental effect on virtue and no possibility of creating sublime work
23.
Wave equation
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The wave equation is an important second-order linear partial differential equation for the description of waves—as they occur in physics—such as sound waves, light waves and water waves. It arises in fields like acoustics, electromagnetics, and fluid dynamics, historically, the problem of a vibrating string such as that of a musical instrument was studied by Jean le Rond dAlembert, Leonhard Euler, Daniel Bernoulli, and Joseph-Louis Lagrange. In 1746, d’Alembert discovered the wave equation, and within ten years Euler discovered the three-dimensional wave equation. The wave equation is a partial differential equation. It typically concerns a time t, one or more spatial variables x1, x2, …, xn, and a scalar function u = u, whose values could model, for example. The wave equation for u is ∂2 u ∂ t 2 = c 2 ∇2 u where ∇2 is the Laplacian, therefore, the sum of any two solutions is again a solution, in physics this property is called the superposition principle. The wave equation, and modifications of it, are found in elasticity, quantum mechanics, plasma physics. The wave equation in one dimension can be written as follows. This equation is described as having only one space dimension x. The wave equation in one dimension can be derived in a variety of different physical settings. Most famously, it can be derived for the case of a string that is vibrating in a two-dimensional plane, another physical setting for derivation of the wave equation in one space dimension utilizes Hookes Law. The wave equation in the case can be derived from Hookes Law in the following way. In the case of a stress pulse propagating through a beam the beam acts much like a number of springs in series. A beam of constant cross section made from an elastic material has a stiffness K given by K = E A L Where A is the cross sectional area. Traveling means that the shape of these individual arbitrary functions with respect to x stays constant, however the functions are translated left and this was derived by Jean le Rond dAlembert. However, the waveforms F and G may also be generalized functions, in that case, the solution may be interpreted as an impulse that travels to the right or the left. The basic wave equation is a differential equation and so it will adhere to the superposition principle. This means that the net displacement caused by two or more waves is the sum of the displacements which would have been caused by each wave individually
24.
Legitimacy (family law)
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Legitimacy, in traditional Western common law, is the status of a child born to parents who are legally married to each other, and of a child conceived before the parents obtain a legal divorce. Conversely, illegitimacy is the status of a child born outside marriage, depending on the cultural context, legitimacy can affect a childs rights of inheritance to the putative fathers estate and the childs right to bear the fathers surname or title. Illegitimacy has also had consequences for the mothers and childs right to support from the putative father, in medieval Wales, a bastard was defined simply as a child not acknowledged by its father. All children, whether born in or out of wedlock, that were acknowledged by the father enjoyed the legal rights. Englands Statute of Merton stated, regarding illegitimacy, He is a bastard that is born before the marriage of his parents and this definition also applied to situations when a childs parents could not marry, as when one or both were already married or when the relationship was incestuous. The Poor Law of 1576 formed the basis of English bastardy law and its purpose was to punish a bastard childs mother and putative father, and to relieve the parish from the cost of supporting mother and child. By an act of 1576, it was ordered that bastards should be supported by their putative fathers, if the genitor could be found, then he was put under very great pressure to accept responsibility and to maintain the child. Under English law, a bastard was unable to be an heir to real property, in contrast to the situation under civil law, a younger non-bastard brother would have no claim to the land. The Legitimacy Act 1926 of England and Wales legitimized the birth of a if the parents subsequently married each other. The Legitimacy Act 1959 extended the legitimization even if the parents had married others in the meantime, neither the 1926 nor 1959 Acts changed the laws of succession to the British throne and succession to peerage titles. The Family Law Reform Act 1969 allowed a bastard to inherit on the intestacy of his parents, in canon and in civil law, the offspring of putative marriages have also been considered legitimate. Since 2003 in England and Wales,2002 in Northern Ireland and 2006 in Scotland, still, children born out of wedlock may not be eligible for certain federal benefits unless the child has been legitimized in the appropriate jurisdiction. Many other countries have abolished by any legal disabilities of a child born out of wedlock. In France, legal reforms regarding illegitimacy began in the 1970s, the European Convention on the Legal Status of Children Born out of Wedlock came into force in 1978. Countries which ratify it must ensure that children born outside marriage are provided with legal rights as stipulated in the text of this Convention, the Convention was ratified by the UK in 1981 and by Ireland in 1988. Use of the illegitimate child is now rare, even in legal contexts. It has been stricken from passports and legal documents as needlessly insulting and stigmatizing to the child, terms such as extra-marital child, love child and child born out of wedlock are more commonly used. Also used in Britain and other English-speaking countries is bastard, though such as natural child are preferred in polite society
25.
Artillery
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Artillery is a class of large military weapons built to fire munitions far beyond the range and power of infantrys small arms. Early artillery development focused on the ability to breach fortifications, and led to heavy, as technology improved, lighter, more mobile field artillery developed for battlefield use. This development continues today, modern self-propelled artillery vehicles are highly mobile weapons of great versatility providing the largest share of an armys total firepower, in its earliest sense, the word artillery referred to any group of soldiers primarily armed with some form of manufactured weapon or armour. In common speech, the artillery is often used to refer to individual devices, along with their accessories and fittings. However, there is no generally recognised generic term for a gun, howitzer, mortar, and so forth, the United States uses artillery piece, the projectiles fired are typically either shot or shell. Shell is a widely used term for a projectile, which is a component of munitions. By association, artillery may also refer to the arm of service that customarily operates such engines, in the 20th Century technology based target acquisition devices, such as radar, and systems, such as sound ranging and flash spotting, emerged to acquire targets, primarily for artillery. These are usually operated by one or more of the artillery arms, Artillery originated for use against ground targets—against infantry, cavalry and other artillery. An early specialist development was coastal artillery for use against enemy ships, the early 20th Century saw the development of a new class of artillery for use against aircraft, anti-aircraft guns. Artillery is arguably the most lethal form of land-based armament currently employed, the majority of combat deaths in the Napoleonic Wars, World War I, and World War II were caused by artillery. In 1944, Joseph Stalin said in a speech that artillery was the God of War, although not called as such, machines performing the role recognizable as artillery have been employed in warfare since antiquity. The first references in the historical tradition begin at Syracuse in 399 BC. From the Middle Ages through most of the era, artillery pieces on land were moved by horse-drawn gun carriages. In the contemporary era, the artillery and crew rely on wheeled or tracked vehicles as transportation, Artillery used by naval forces has changed significantly also, with missiles replacing guns in surface warfare. The engineering designs of the means of delivery have likewise changed significantly over time, in some armies, the weapon of artillery is the projectile, not the equipment that fires it. The process of delivering fire onto the target is called gunnery, the actions involved in operating the piece are collectively called serving the gun by the detachment or gun crew, constituting either direct or indirect artillery fire. The term gunner is used in armed forces for the soldiers and sailors with the primary function of using artillery. The gunners and their guns are usually grouped in teams called either crews or detachments, several such crews and teams with other functions are combined into a unit of artillery, usually called a battery, although sometimes called a company
26.
Patron saint
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Catholics believe that patron saints, having already transcended to the metaphysical, are able to intercede effectively for the needs of their special charges. Historically, a practice has also occurred in many Islamic lands. With regard to the omnipresence of this belief, the late Martin Lings wrote. Traditionally, it has been understood that the saint of a particular place prays for that places wellbeing and for the health. Saints often become the patrons of places where they were born or had been active, professions sometimes have a patron saint owing to that individual being involved somewhat with it, although some of the connections were tenuous. Lacking such a saint, an occupation would have a patron whose acts or miracles in some way recall the profession and it is, however, generally discouraged in some Protestant branches such as Calvinism, where the practice is considered a form of idolatry. In Islam, the veneration or commemoration and recognition of saints is found in many branches of traditional Sunnism
27.
Orphanage
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An orphanage is a residential institution devoted to the care of orphans—children whose biological parents are deceased or otherwise unable or unwilling to care for them. It is frequently used to describe institutions abroad, where it is an accurate term. Most children who live in orphanages are not orphans, four out of five children in orphanages having at least one living parent, most orphanages have been closed in Europe and North America. Few large international charities continue to fund orphanages, however, they are still commonly founded by smaller charities, especially in developing countries, orphanages may prey on vulnerable families at risk of breakdown and actively recruit children to ensure continued funding. Orphanages in developing countries are run by the state. Other residential institutions for children can be called group homes, childrens homes, refuges, rehabilitation centers, night shelters, the Romans formed their first orphanages around 400 AD. Jewish law prescribed care for the widow and the orphan, plato says, Orphans should be placed under the care of public guardians. Men should have a fear of the loneliness of orphans and of the souls of their departed parents, a man should love the unfortunate orphan of whom he is guardian as if he were his own child. He should be as careful and as diligent in the management of the property as of his own or even more careful still. The care of orphans was referred to bishops and, during the Middle Ages, as soon as they were old enough, children were often given as apprentices to households to ensure their support and to learn an occupation. In medieval Europe, care for orphans tended to reside with the Church, the Elizabethan Poor Laws were enacted at the time of the Reformation, and placed public responsibility on individual parishes to care for the indigent poor. The growth of sentimental philanthropy in the 18th century, led to the establishment of the first charitable institutions catering for the orphan, the first children were admitted into a temporary house located in Hatton Garden. At first, no questions were asked about child or parent, on reception, children were sent to wet nurses in the countryside, where they stayed until they were about four or five years old. At sixteen, girls were apprenticed as servants for four years, at fourteen, boys were apprenticed into variety of occupations. There was a benevolent fund for adults. A basket was accordingly hung outside the hospital, the age for admission was raised from two months to twelve, and a flood of children poured in from country workhouses. Parliament soon came to the conclusion that the indiscriminate admission should be discontinued, the hospital adopted a system of receiving children only with considerable sums. This practice was stopped in 1801, and it henceforth became a fundamental rule that no money was to be received
28.
Child abandonment
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Child abandonment is the practice of relinquishing interests and claims over ones offspring in an extralegal way with the intent of never again resuming or reasserting them. Causes include many social and cultural factors as well as mental illness, an abandoned child is called a foundling. Baby dumping refers to parents abandoning or discarding a child younger than 12 months in a public or private place with the intent of disposing of them and it is also known as rehoming in cases of failed adoptions. Poverty is often a cause of child abandonment. People in cultures with poor social welfare systems who are not financially capable of taking care of a child are more likely to abandon them, another common reason for baby dumping is teenage pregnancies. Pregnant teenagers experience problems during and after due to social and psychological distress. Regardless of age, parents may abandon a child because they are unprepared to raise them, other reasons include unpreferred gender, appearance, or other characteristics of the child as well as mental or physical handicaps of the child. Education, family planning, government support, and post-natal services, historically, many cultures practiced abandonment of infants, called infant exposure. Although such children would survive if taken up by others, exposure is considered a form of infanticide—as described by Tertullian in his Apology. By exposure to cold and hunger and dogs, medieval laws in Europe governing child abandonment, as for example the Visigothic Code, often prescribed that the person who had taken up the child was entitled to the childs service as a slave. Conscripting or enslaving children into armies and labor pools often occurred as a consequence of war or pestilence when many children were left parentless, abandoned children then became the ward of the state, military organization, or religious group. When this practice happened en masse, it had the advantage of ensuring the strength and continuity of cultural, the largest migration of abandoned children in history took place in the United States between 1854 and 1929. Over two hundred thousand orphans were forced onto railroad cars and shipped west, where any family desiring their services as laborers, maids, orphan trains were highly popular as a source of free labor. The sheer size of the displacement and degree of exploitation that occurred gave rise to new agencies, eventually, adoption became a quintessential American institution, embodying faith in social engineering and mobility. By 1945, adoption was formulated as an act with consideration of the child’s best interests. Brace feared the impact of the poverty and their Catholic religion, in particular. Reformers during the Progressive Era later carried on this tradition of secrecy when drafting American laws. Today, abandonment of a child is considered to be a crime in many jurisdictions because it can be considered malum in se due to the direct harm to the child
29.
Glazier
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A glazier is a skilled tradesman responsible for cutting, installing, and removing glass. Glaziers may work with glass in various surfaces and settings, such as windows, doors, shower doors, skylights, storefronts, display cases, mirrors, facades, interior walls, ceilings, the Occupational Outlook Handbook of the U. S. Uses and maintains tools and equipment 2, performs routine activities Block B – Commercial Window and Door Systems 4. Fabricates commercial window and door systems 5, installs commercial window and door systems Block C – Residential Window and Door Systems 6. Installs residential door systems Block D – Specialty Glass and Products 8, fabricates and installs specialty glass and products 9. Installs glass systems on vehicles Block E – Servicing 10, services commercial window and door systems 11. Services residential window and door systems 12, tools used by glaziers include cutting boards, glass-cutting blades, straightedges, glazing knives, saws, drills, grinders, putty, and glazing compounds. Some glaziers work specifically with glass in motor vehicles, other work specifically with the safety glass used in aircraft. Glaziers are typically educated at the high school diploma or equivalent level and learn the skills of the trade through an apprenticeship program, in the U. S. apprenticeship programs are offered through the National Glass Association as well as trade associations and local contractors associations. Construction-industry glaziers are frequently members of the International Union of Painters, in Ontario, Canada, apprenticeships are offered at the provincial level and certified through the Ontario College of Trades. Other provinces manage their own apprenticeship programs, the Trade of Glazier is a designated Red Seal Trade in Canada. Occupational hazards encountered by glaziers include the risks of being cut by glass or tools, according to the Occupational Outlook Handbook, there are some 45,300 glaziers in the United States, with median pay of $38,410 per year in 2014. Among the 50 states, only Connecticut and Florida require glaziers to hold a license, architectural glass Glazing in architecture Insulated glazing Stained glass Glass manufacturing Glassblowing Media related to Glaziers at Wikimedia Commons
30.
French livre
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The livre was the currency of France from 781 to 1794. Several different livres existed, some concurrently, the livre was the name of both units of account and coins. The livre was established by Charlemagne as a unit of account equal to one pound of silver and it was subdivided into 20 sous, each of 12 deniers. The word livre came from the Latin word libra, a Roman unit of weight and this system and the denier itself served as the model for many of Europes currencies, including the British pound, Italian lira, Spanish dinero and the Portuguese dinheiro. This first livre is known as the livre carolingienne, only deniers were initially minted, but debasement led to larger denominations being issued. Different mints in different regions used different weights for the denier, livre is a homonym of the French word for book, the distinction being that the two have a different gender. The monetary unit is feminine, la/une livre, while book is masculine, for much of the Middle Ages, different duchies of France were semi-autonomous if not practically independent from the weak Capetian kings, and thus each minted their own currency. Charters would need to specify which region or mint was being used, the first steps towards standardization came under the first strong Capetian monarch, Philip II Augustus. Philip II conquered much of the continental Angevin Empire from King John of England, including Normandy, Anjou and this was a slow process lasting many decades and not completed within Philip IIs lifetime. Until the thirteenth century and onwards, only deniers were actually minted as coin money, both livres and sous did not actually exist as coins but were used only for accounting purposes. Between 1360 and 1641, coins worth 1 livre tournois were minted known as francs and this name persisted in common parlance for 1 livre tournois but was not used on coins or paper money. The official use of the livre tournois accounting unit in all contracts in France was legislated in 1549, however, in 1577, the livre tournois accounting unit was officially abolished and replaced by the écu, which was at that time the major French gold coin in actual circulation. In 1602, the livre tournois accounting unit was brought back, Louis XIII of France stopped minting the franc in 1641, replacing it with coins based on the silver écu and gold Louis dor. The écu and louis dor fluctuated in value, with the écu varying between three and six livres tournois until 1726 when it was fixed at six livres, the louis was initially worth ten livres, and fluctuated too, until its value was fixed at twenty-four livres in 1726. In 1667, the livre parisis was officially abolished, however, the sole remaining livre was still frequently referred to as the livre tournois until its demise. The first French paper money was issued in 1701 and was denominated in livres tournois, however, the notes did not hold their value relative to silver due to massive over–production. The Banque Royale crashed in 1720, rendering the banknotes worthless, in 1726, under Louis XVs minister Cardinal Fleury, a system of monetary stability was put in place. Eight ounces of gold was worth 740 livres,9 sols,8 ounces of silver was worth 51 livres,2 sols,3 deniers
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Jansenism
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Jansenism was a Catholic heretical theological movement, primarily in France, that emphasized original sin, human depravity, the necessity of divine grace, and predestination. The movement originated from the published work of the Dutch theologian Cornelius Jansen. It was first popularized by Jansens friend Abbot Jean Duvergier de Hauranne, of Saint-Cyran-en-Brenne Abbey, through the 17th and into the 18th centuries, Jansenism was a distinct movement within the Catholic Church. The theological centre of the movement was the convent of Port-Royal Abbey, Paris, which was a haven for writers including Duvergier, Arnauld, Pierre Nicole, Blaise Pascal, Jansenism was opposed by many in the Catholic hierarchy, especially the Jesuits. Although the Jansenists identified themselves only as rigorous followers of Augustine of Hippos teachings, Jansenist leaders endeavored to accommodate the popes pronouncements while retaining their uniqueness, and enjoyed a measure of peace in the late 17th century under Pope Clement IX. However, further controversy led to the apostolic constitution Unigenitus Dei Filius, promulgated by Pope Clement XI in 1713, the origins of Jansenism lie in the friendship of Jansen and Duvergier, who met in the early 17th century when both were studying theology at the University of Leuven. Duvergier was Jansens patron for a number of years, getting Jansen a job as a tutor in Paris in 1606, two years later, he got Jansen a position teaching at the bishops college in Duvergiers hometown of Bayonne. The duo studied the Church Fathers together, with a focus on the thought of Augustine of Hippo. Duvergier became abbot of Saint Cyran Abbey in Brenne and was known as the Abbé de Saint-Cyran for the rest of his life, Jansen returned to the University of Leuven, where he completed his doctorate in 1619 and was named professor of exegesis. Jansen and Duvergier continued to correspond about Augustine, especially Augustines teachings on grace, upon the recommendation of King Philip IV of Spain, Jansen was consecrated as bishop of Ypres in 1636. Jansen died in a 1638 epidemic and this manuscript, published in 1640 as Augustinus, expounded Augustines system and formed the basis for the subsequent Jansenist Controversy. Jansen emphasized a particular reading of Augustines idea of efficacious grace which stressed that only a portion of humanity were predestined to be saved. Jansen insisted that the love of God was fundamental, and that only perfect contrition, Duvergier was not released until after Richelieus death in 1642, and he died shortly thereafter, in 1643. Jansen also insisted on justification by faith, although he did not contest the necessity of revering saints, of confession, Jansens opponents condemned his teachings for their alleged similarities to Calvinism. Pascal himself claimed that Molinists were correct concerning the state of humanity before the Fall, the heresy of Jansenism, as stated by subsequent Roman Catholic doctrine, lay in denying the role of free will in the acceptance and use of grace. Jansenism asserts that Gods role in the infusion of grace cannot be resisted, Catholic doctrine, in the Catechism of the Catholic Church, is that Gods free initiative demands mans free response—that is, humans freely assent or refuse Gods gift of grace. However, on August 1,1642, the Holy Office issued a decree condemning Augustinus, in 1602, Marie Angélique Arnauld become abbess of Port-Royal-des-Champs, a Cistercian convent in Magny-les-Hameaux. There, she reformed discipline after an experience in 1608
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Bachelor of Arts
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A Bachelor of Arts is a bachelors degree awarded for an undergraduate course or program in either the liberal arts, the sciences, or both. Bachelor of Arts degree programs take three to four years depending on the country, academic institution, and specific specializations, majors or minors. The word baccalaureus or baccalarium should not be confused with baccalaureatus, degree diplomas generally are printed on high-quality paper or parchment, individual institutions set the preferred abbreviation for their degrees. In Pakistan, the Bachelor of Arts degree can also be attained within two years as an external degree, in colleges and universities in Australia, New Zealand, Nepal and South Africa, the BA degree can be taken over three years of full-time study. Unlike in other countries, students do not receive a grade for their Bachelor of Arts degree with varying levels of honours. Qualified students may be admitted, after they have achieved their Bachelors program with an overall grade point average. Thus, to achieve a Bachelor Honours degree, a postgraduate year. A student who holds a Honours degree is eligible for entry to either a Doctorate or a very high research Master´s degree program. Education in Canada is controlled by the Provinces and can be different depending on the province in Canada. Canadian universities typically offer a 3-year Bachelor of Arts degrees, in many universities and colleges, Bachelor of Arts degrees are differentiated either as Bachelors of Arts or as honours Bachelor of Arts degree. The honours degrees are designated with the abbreviation in brackets of. It should not be confused with the consecutive Bachelor of Arts degree with Honours, Latin Baccalaureatus in Artibus Cum Honore, BA hon. de jure without brackets and with a dot. It is a degree, which is considered to be the equivalent of a corresponding maîtrise degree under the French influenced system. Going back in history, a three-year Bachelor of Arts degree was called a pass degree or general degree. Students may be required to undertake a long high-quality research empirical thesis combined with a selection of courses from the relevant field of studies. The consecutive B. cum Honore degree is essential if students ultimate goal is to study towards a two- or three-year very high research masters´ degree qualification. A student holding a Baccalaureatus Cum Honore degree also may choose to complete a Doctor of Philosophy program without the requirement to first complete a masters degree, over the years, in some universities certain Baccalaureatus cum Honore programs have been changed to corresponding master´s degrees. In general, in all four countries, the B. A. degree is the standard required for entry into a masters programme, in science, a BA hons degree is generally a prerequisite for entrance to a Ph. D program or a very-high-research-activity master´s programme
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Ecclesiology
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The word ecclesiology was defined in the 19th century as the science of the building and decoration of church buildings and at least one publication still uses the word in this sense. The Ecclesiologist was first published in October 1841 and dealt with the study of the building and its successor Ecclesiology Today is still, as of 2017, being published by The Ecclesiological Society. The situation regarding the etymology has been summed up by Alister McGrath, is it a visible or earthly corporation, or a unified and visible society — a church in the sense of a specific denomination or institution, for instance. Or is it the body of all believing Christians, regardless of their denominational differences, what is the relationship between living Christians and departed Christians —do they constitute together the Church. What is the relationship between a believer and the Church and that is, what is the role of corporate worship in the spiritual lives of believers. Can salvation be found outside of formal membership in a faith community. What is the authority of the Church, who gets to interpret the doctrines of the Church. Is the organizational structure itself, either in a corporate body, or generally within the range of formal church structures. For example, is the Bible a written part of a wider revelation entrusted to the Church as faith community, or is the Bible the revelation itself, and the Church is to be defined as a group of people who claim adherence to it. What are the sacraments, divine ordinances, and liturgies, in the context of the Church, what is the comparative emphasis and relationship between worship service, spiritual formation, and mission, and is the Churchs role to create disciples of Christ or some other function. Is the Eucharist the defining element of the rest of the sacramental system, is the Church to be understood as the vehicle for salvation, or the salvific presence in the world, or as a community of those already saved. How should the Church be governed, what was the mission and authority of the Apostles, and is this handed down through the sacraments today. What are the methods of choosing clergy such as bishops and priests. Who are the leaders of a church, must there be a policy-making board of leaders within a church and what are the qualifications for this position, and by what process do these members become official, ordained leaders. Must leaders and clergy be ordained, and is possible only by those who have been ordained by others. What are the roles of spiritual gifts in the life of the church, how does the Churchs New Covenant relate to the covenants expressed in scripture with Gods chosen people, the Jewish people. What is the destiny of the Church in Christian eschatology. This shift is most clearly marked by the encyclical Divino afflante Spiritu in 1943, avery Robert Cardinal Dulles, S. J. contributed greatly to the use of models in understanding ecclesiology
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Lawyer
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A lawyer is a person who practices law, as an advocate, barrister, attorney, counselor or solicitor or chartered legal executive. The role of the lawyer varies greatly across legal jurisdictions, in practice, legal jurisdictions exercise their right to determine who is recognized as being a lawyer. As a result, the meaning of the lawyer may vary from place to place. In Australia, the lawyer is used to refer to both barristers and solicitors. In Canada, the word lawyer refers to individuals who have been called to the bar or. Common law lawyers in Canada are formally and properly called barristers and solicitors, however, in Quebec, civil law advocates often call themselves attorney and sometimes barrister and solicitor in English. The Legal Services Act 2007 defines the activities that may only be performed by a person who is entitled to do so pursuant to the Act. Lawyer is not a protected title, in India, the term lawyer is often colloquially used, but the official term is advocate as prescribed under the Advocates Act,1961. In Scotland, the word refers to a more specific group of legally trained people. It specifically includes advocates and solicitors, in a generic sense, it may also include judges and law-trained support staff. In the United States, the term refers to attorneys who may practice law. It is never used to refer to patent agents or paralegals, in fact, there are regulatory restrictions on non-lawyers like paralegals practicing law. Other nations tend to have terms for the analogous concept. In most countries, particularly civil law countries, there has been a tradition of giving many legal tasks to a variety of civil law notaries, clerks, and scriveners. Several countries that originally had two or more legal professions have since fused or united their professions into a type of lawyer. Most countries in this category are common law countries, though France, in countries with fused professions, a lawyer is usually permitted to carry out all or nearly all the responsibilities listed below. Arguing a clients case before a judge or jury in a court of law is the province of the barrister in England. However, the boundary between barristers and solicitors has evolved, in England today, the barrister monopoly covers only appellate courts, and barristers must compete directly with solicitors in many trial courts
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Frederick the Great
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Frederick II was King of Prussia from 1740 until 1786, the longest reign of any Hohenzollern king. Frederick was the last titled King in Prussia and declared himself King of Prussia after achieving full sovereignty for all historical Prussian lands, Prussia had greatly increased its territories and became a leading military power in Europe under his rule. He became known as Frederick the Great and was affectionately nicknamed Der Alte Fritz by the Prussian, in his youth, Frederick was more interested in music and philosophy than the art of war. Upon ascending to the Prussian throne, he attacked Austria and claimed Silesia during the Silesian Wars, winning acclaim for himself. Near the end of his life, Frederick physically connected most of his realm by conquering Polish territories in the First Partition of Poland and he was an influential military theorist whose analysis emerged from his extensive personal battlefield experience and covered issues of strategy, tactics, mobility and logistics. Considering himself the first servant of the state, Frederick was a proponent of enlightened absolutism and he modernized the Prussian bureaucracy and civil service and pursued religious policies throughout his realm that ranged from tolerance to segregation. He reformed the system and made it possible for men not of noble stock to become judges. Frederick also encouraged immigrants of various nationalities and faiths to come to Prussia, some critics, however, point out his oppressive measures against conquered Polish subjects during the First Partition. Frederick supported arts and philosophers he favored, as well as allowing complete freedom of the press, Frederick is buried at his favorite residence, Sanssouci in Potsdam. Because he died childless, Frederick was succeeded by his nephew, Frederick William II, son of his brother, historian Leopold von Ranke was unstinting in his praise of Fredericks Heroic life, inspired by great ideas, filled with feats of arms. Immortalized by the raising of the Prussian state to the rank of a power, Johann Gustav Droysen was even more extolling. However, by the 21st century, a re-evaluation of his legacy as a great warrior, Frederick, the son of Frederick William I and his wife, Sophia Dorothea of Hanover, was born in Berlin on 24 January 1712. The birth of Frederick was welcomed by his grandfather, Frederick I, with more than usual pleasure, with the death of his father in 1713, Frederick William became King of Prussia, thus making young Frederick the crown prince. The new king wished for his sons and daughters to be educated not as royalty and he had been educated by a Frenchwoman, Madame de Montbail, who later became Madame de Rocoulle, and he wished that she educate his children. However, he possessed a violent temper and ruled Brandenburg-Prussia with absolute authority. As Frederick grew, his preference for music, literature and French culture clashed with his fathers militarism, in contrast, Fredericks mother Sophia was polite, charismatic and learned. Her father, George Louis of Brunswick-Lüneburg, succeeded to the British throne as King George I in 1714, Frederick was brought up by Huguenot governesses and tutors and learned French and German simultaneously. Although Frederick William I was raised a Calvinist, he feared he was not of the elect, to avoid the possibility of Frederick being motivated by the same concerns, the king ordered that his heir not be taught about predestination
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Classical mechanics
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In physics, classical mechanics is one of the two major sub-fields of mechanics, along with quantum mechanics. Classical mechanics is concerned with the set of physical laws describing the motion of bodies under the influence of a system of forces. The study of the motion of bodies is an ancient one, making classical mechanics one of the oldest and largest subjects in science, engineering and technology. Classical mechanics describes the motion of objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars. Within classical mechanics are fields of study that describe the behavior of solids, liquids and gases, Classical mechanics also provides extremely accurate results as long as the domain of study is restricted to large objects and the speeds involved do not approach the speed of light. When both quantum and classical mechanics cannot apply, such as at the level with high speeds. Since these aspects of physics were developed long before the emergence of quantum physics and relativity, however, a number of modern sources do include relativistic mechanics, which in their view represents classical mechanics in its most developed and accurate form. Later, more abstract and general methods were developed, leading to reformulations of classical mechanics known as Lagrangian mechanics and these advances were largely made in the 18th and 19th centuries, and they extend substantially beyond Newtons work, particularly through their use of analytical mechanics. The following introduces the concepts of classical mechanics. For simplicity, it often models real-world objects as point particles, the motion of a point particle is characterized by a small number of parameters, its position, mass, and the forces applied to it. Each of these parameters is discussed in turn, in reality, the kind of objects that classical mechanics can describe always have a non-zero size. Objects with non-zero size have more complicated behavior than hypothetical point particles, because of the degrees of freedom. However, the results for point particles can be used to such objects by treating them as composite objects. The center of mass of a composite object behaves like a point particle, Classical mechanics uses common-sense notions of how matter and forces exist and interact. It assumes that matter and energy have definite, knowable attributes such as where an object is in space, non-relativistic mechanics also assumes that forces act instantaneously. The position of a point particle is defined with respect to a fixed reference point in space called the origin O, in space. A simple coordinate system might describe the position of a point P by means of a designated as r. In general, the point particle need not be stationary relative to O, such that r is a function of t, the time
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Newton's laws of motion
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Newtons laws of motion are three physical laws that, together, laid the foundation for classical mechanics. They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces. More precisely, the first law defines the force qualitatively, the second law offers a measure of the force. These three laws have been expressed in different ways, over nearly three centuries, and can be summarised as follows. The three laws of motion were first compiled by Isaac Newton in his Philosophiæ Naturalis Principia Mathematica, Newton used them to explain and investigate the motion of many physical objects and systems. For example, in the volume of the text, Newton showed that these laws of motion, combined with his law of universal gravitation. Newtons laws are applied to objects which are idealised as single point masses, in the sense that the size and this can be done when the object is small compared to the distances involved in its analysis, or the deformation and rotation of the body are of no importance. In this way, even a planet can be idealised as a particle for analysis of its orbital motion around a star, in their original form, Newtons laws of motion are not adequate to characterise the motion of rigid bodies and deformable bodies. Leonhard Euler in 1750 introduced a generalisation of Newtons laws of motion for rigid bodies called Eulers laws of motion, if a body is represented as an assemblage of discrete particles, each governed by Newtons laws of motion, then Eulers laws can be derived from Newtons laws. Eulers laws can, however, be taken as axioms describing the laws of motion for extended bodies, Newtons laws hold only with respect to a certain set of frames of reference called Newtonian or inertial reference frames. Other authors do treat the first law as a corollary of the second, the explicit concept of an inertial frame of reference was not developed until long after Newtons death. In the given mass, acceleration, momentum, and force are assumed to be externally defined quantities. This is the most common, but not the interpretation of the way one can consider the laws to be a definition of these quantities. Newtonian mechanics has been superseded by special relativity, but it is useful as an approximation when the speeds involved are much slower than the speed of light. The first law states that if the net force is zero, the first law can be stated mathematically when the mass is a non-zero constant, as, ∑ F =0 ⇔ d v d t =0. Consequently, An object that is at rest will stay at rest unless a force acts upon it, an object that is in motion will not change its velocity unless a force acts upon it. This is known as uniform motion, an object continues to do whatever it happens to be doing unless a force is exerted upon it. If it is at rest, it continues in a state of rest, if an object is moving, it continues to move without turning or changing its speed
