1.
Petit Luxembourg
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The Petit Luxembourg is a French hôtel particulier, currently the residence of the president of the French Senate. It is located at 17–17 bis, rue de Vaugirard, just west of the Senates main building, originally built around 1550 to the designs of an unknown architect, it is especially noted for the surviving Rococo interiors designed in 1710–1713 by the French architect Germain Boffrand. Further west, at 19 rue de Vaugirard, is the Musée du Luxembourg, Marie de Médicis purchased the hôtel in 1612 when she began acquiring property for the construction of the adjacent Luxembourg Palace. The old hôtel soon became known as the Petit Luxembourg to distinguish it from the larger building, richelieu left the Petit Luxembourg to his niece, the Duchess of Aiguillon. It was inherited in turn by the Grand Condé, who left it to his son, the latters widow, Anne of Bavaria, Princess Palatine, engaged the architect Germain Boffrand to enlarge and redecorate it between 1710 and 1713. Boffrand demolished the buildings to the west of the courtyard. The new wing preserved the style of the old corps de logis to the east and incorporated vestiges of the Couvent des Filles-du-Calvaire and these can still be seen in the winter garden and the Mannerist interior of the Queens Chapel. Between the street and the courtyard Boffrand added a screen which connected the old to the new. Its portal is flanked by Tuscan columns on the courtyard side. The upper floor contains a corridor connecting the east and west wings, although Boffrand preserved the façades of the older wing, he completely redesigned the interior. A modest vestibule with Ionic columns leads directly to a grand two-storey stair hall decorated on the floor with pilasters of the Composite order, elaborate carvings. The staircase, much admired in its day, sweeps up to the piano nobile in a flight, its grandeur enhanced with balustrades of stone. The princesss apartments lead directly off the landing, the first room no longer has the original décor, but the next still has Boffrands ceiling, cornices, and frieze. The following room, the Grand Salon also retains these elements, in large rooms, such as the stair hall and the Grand Salon, Boffrands unit of design was not the wall, but rather the entire room. Each wall consisted of an arcade, which pulled the space together and subordinated doors, windows. The focus of the décor was high in the spandrels between the arches, not in the panels as seen with Lepautre. This principle, first employed by J. H. Mansart at the Grand Trianon, kept the main part of the surface free for hangings, such as tapestries. The band of ornate spandrels running around the room achieves a unity, Boffrands decorative motifs, the linked C-scrolls entwined with palmettes and festoons, are more similar to those of Jean Bérain than Lepautre
2.
Paris
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Paris is the capital and most populous city of France. It has an area of 105 square kilometres and a population of 2,229,621 in 2013 within its administrative limits, the agglomeration has grown well beyond the citys administrative limits. By the 17th century, Paris was one of Europes major centres of finance, commerce, fashion, science, and the arts, and it retains that position still today. The aire urbaine de Paris, a measure of area, spans most of the Île-de-France region and has a population of 12,405,426. It is therefore the second largest metropolitan area in the European Union after London, the Metropole of Grand Paris was created in 2016, combining the commune and its nearest suburbs into a single area for economic and environmental co-operation. Grand Paris covers 814 square kilometres and has a population of 7 million persons, the Paris Region had a GDP of €624 billion in 2012, accounting for 30.0 percent of the GDP of France and ranking it as one of the wealthiest regions in Europe. The city is also a rail, highway, and air-transport hub served by two international airports, Paris-Charles de Gaulle and Paris-Orly. Opened in 1900, the subway system, the Paris Métro. It is the second busiest metro system in Europe after Moscow Metro, notably, Paris Gare du Nord is the busiest railway station in the world outside of Japan, with 262 millions passengers in 2015. In 2015, Paris received 22.2 million visitors, making it one of the top tourist destinations. The association football club Paris Saint-Germain and the rugby union club Stade Français are based in Paris, the 80, 000-seat Stade de France, built for the 1998 FIFA World Cup, is located just north of Paris in the neighbouring commune of Saint-Denis. Paris hosts the annual French Open Grand Slam tennis tournament on the red clay of Roland Garros, Paris hosted the 1900 and 1924 Summer Olympics and is bidding to host the 2024 Summer Olympics. The name Paris is derived from its inhabitants, the Celtic Parisii tribe. Thus, though written the same, the name is not related to the Paris of Greek mythology. In the 1860s, the boulevards and streets of Paris were illuminated by 56,000 gas lamps, since the late 19th century, Paris has also been known as Panam in French slang. Inhabitants are known in English as Parisians and in French as Parisiens and they are also pejoratively called Parigots. The Parisii, a sub-tribe of the Celtic Senones, inhabited the Paris area from around the middle of the 3rd century BC. One of the areas major north-south trade routes crossed the Seine on the île de la Cité, this place of land and water trade routes gradually became a town
3.
French people
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The French are an ethnic group and nation who are identified with the country of France. This connection may be legal, historical, or cultural, modern French society can be considered a melting pot. To be French, according to the first article of the French Constitution, is to be a citizen of France, regardless of origin, race. The debate concerning the integration of this view with the underlying the European Community remains open. A large number of foreigners have traditionally been permitted to live in France, indeed, the country has long valued its openness, tolerance and the quality of services available. Application for French citizenship is often interpreted as a renunciation of previous state allegiance unless a dual citizenship agreement exists between the two countries, the European treaties have formally permitted movement and European citizens enjoy formal rights to employment in the state sector. Seeing itself as a nation with universal values, France has always valued. However, the success of such assimilation has recently called into question. There is increasing dissatisfaction with, and within, growing ethno-cultural enclaves, the 2005 French riots in some troubled and impoverished suburbs were an example of such tensions. However they should not be interpreted as ethnic conflicts but as social conflicts born out of socioeconomic problems endangering proper integration, the name France etymologically derives from the word Francia, the territory of the Franks. The Franks were a Germanic tribe that overran Roman Gaul at the end of the Roman Empire, in the pre-Roman era, all of Gaul was inhabited by a variety of peoples who were known collectively as the Gaulish tribes. Gaul was militarily conquered in 58-51 BCE by the Roman legions under the command of General Julius Caesar, the area then became part of the Roman Empire. Over the next five centuries the two cultures intermingled, creating a hybridized Gallo-Roman culture, the Gaulish vernacular language disappeared step by step to be replaced everywhere by Vulgar Latin, which would later develop under Frankish influence into the French language in the North of France. With the decline of the Roman Empire in Western Europe, a federation of Germanic peoples entered the picture, the Franks were Germanic pagans who began to settle in northern Gaul as laeti, already during the Roman era. They continued to filter across the Rhine River from present-day Netherlands, at the beginning, they served in the Roman army and reached high commands. Their language is spoken as a kind of Dutch in northern France. Another Germanic people immigrated massively to Alsace, the Alamans, which explains the Alemannic German spoken there and they were competitors of the Franks, thats why it became at the Renaissance time the word for German in French, Allemand. By the early 6th century the Franks, led by the Merovingian king Clovis I and his sons, had consolidated their hold on much of modern-day France, the Vikings eventually intermarried with the local people, converting to Christianity in the process
4.
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
5.
Carnot cycle
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The Carnot cycle is a theoretical thermodynamic cycle proposed by Nicolas Léonard Sadi Carnot in 1824 and expanded upon by others in the 1830s and 1840s. It is not an actual thermodynamic cycle but is a theoretical construct, every single thermodynamic system exists in a particular state. When a system is taken through a series of different states and finally returned to its initial state, in the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine. A system undergoing a Carnot cycle is called a Carnot heat engine, although such an engine is only a theoretical construct. However, a microscopic Carnot heat engine has been designed and run, essentially, there are two systems at temperatures Th and Tc, which are so large that their temperatures are practically unaffected by a single cycle. As such, they are called heat reservoirs, since the cycle is reversible, there is no generation of entropy during the cycle, entropy is conserved. During the cycle, an amount of entropy ΔS is extracted from the hot reservoir. The difference in the two energies ΔS is equal to the work done by the engine, the Carnot cycle when acting as a heat engine consists of the following steps, Reversible isothermal expansion of the gas at the hot temperature, T1. During this step the gas is allowed to expand and it work on the surroundings. The temperature of the gas does not change during the process, the gas expansion is propelled by absorption of heat energy Q1 from the high temperature reservoir and results in an increase of entropy of the gas in the amount Δ S1 = Q1 / T1. For this step the mechanisms of the engine are assumed to be thermally insulated, the gas continues to expand, doing work on the surroundings, and losing an amount of internal energy equal to the work that leaves the system. The gas expansion causes it to cool to the cold temperature, Reversible isothermal compression of the gas at the cold temperature, T2. Once again the mechanisms of the engine are assumed to be thermally insulated, at this point the gas is in the same state as at the start of step 1. In this case, Δ S1 = Δ S2, or and this is true as Q2 and T2 are both lower and in fact are in the same ratio as Q1 / T1. For a simple closed system, any point on the graph represent a particular state of the system. A thermodynamic process will consist of a curve connecting an initial state, the area under the curve will be, Q = ∫ A B T d S which is the amount of thermal energy transferred in the process. If the process moves to greater entropy, the area under the curve will be the amount of absorbed by the system in that process. If the process moves towards lesser entropy, it will be the amount of heat removed, for any cyclic process, there will be an upper portion of the cycle and a lower portion
6.
Carnot's theorem (thermodynamics)
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Carnots theorem, developed in 1824 by Nicolas Léonard Sadi Carnot, also called Carnots rule, is a principle that specifies limits on the maximum efficiency any heat engine can obtain. The efficiency of a Carnot engine depends solely on the difference between the hot and cold temperature reservoirs, Carnots theorem states, All heat engines between two heat reservoirs are less efficient than a Carnot heat engine operating between the same reservoirs. Every Carnot heat engine between a pair of reservoirs is equally efficient, regardless of the working substance employed or the operation details. Based on modern thermodynamics, Carnots theorem is a result of the law of thermodynamics. Historically, however, it was based on contemporary caloric theory, the proof of the Carnot theorem is a proof by contradiction, or reductio ad absurdum, as illustrated by the figure showing two heat engines operating between two reservoirs of different temperature. The heat engine with more efficiency is driving a heat engine with less efficiency and this pair of engines receives no outside energy, and operates solely on the energy released when heat is transferred from the hot and into the cold reservoir. However, if η M > η L, then the net heat flow would be backwards, i. e. into the hot reservoir and it is generally agreed that this is impossible because it violates the second law of thermodynamics. We begin by verifying the values of work and heat flow depicted in the figure, first, we must point out an important caveat, the engine with less efficiency is being driven as a heat pump, and therefore must be a reversible engine. If the less efficient engine is not reversible, then the device could be built, a reversible heat engine with low thermodynamic efficiency, W / Q h delivers more heat to the hot reservoir for a given amount of work when it is being driven as a heat pump. Having established that the flow values shown in the figure are correct, Carnots theorem may be proven for irreversible. As the figure shows, this will cause heat to flow from the cold to the hot reservoir without any work or energy. Therefore both heat engines have the same efficiency, and we conclude that, All reversible engines that operate between the two heat reservoirs have the same efficiency. This is an important result because it helps establish the Clausius theorem, Δ S = ∫ a b d Q r e v T, over all paths. If this integral were not path independent, then entropy, S, if one of the engines is irreversible, it must be the engine, placed so that it reverse drives the less efficient but reversible engine. But if this engine is more efficient than the reversible engine. The efficiency of the engine is the work divided by the heat introduced to the system or where wcy is the work done per cycle, thus, the efficiency depends only on qC/qH. This can only be the case if f = q 3 q 1 = q 2 q 3 q 1 q 2 = f f, specializing to the case that T1 is a fixed reference temperature, the temperature of the triple point of water. Then for any T2 and T3, f = f f =273.16 ⋅ f 273.16 ⋅ f and this is because Carnots theorem applies to engines converting thermal energy to work, whereas fuel cells and batteries instead convert chemical energy to work
7.
Carnot heat engine
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A Carnot heat engine is an engine that operates on the reversible Carnot cycle. The basic model for this engine was developed by Nicolas Léonard Sadi Carnot in 1824, the Carnot engine model was graphically expanded upon by Benoît Paul Émile Clapeyron in 1834 and mathematically elaborated upon by Rudolf Clausius in 1857 from which the concept of entropy emerged. Every thermodynamic system exists in a particular state, a thermodynamic cycle occurs when a system is taken through a series of different states, and finally returned to its initial state. In the process of going through this cycle, the system may perform work on its surroundings, a heat engine acts by transferring energy from a warm region to a cool region of space and, in the process, converting some of that energy to mechanical work. The cycle may also be reversed, in the adjacent diagram, from Carnots 1824 work, Reflections on the Motive Power of Fire, there are two bodies A and B, kept each at a constant temperature, that of A being higher than that of B. These two bodies to which we can give, or from which we can remove the heat without causing their temperatures to vary, exercise the functions of two unlimited reservoirs of caloric. We will call the first the furnace and the second the refrigerator. ”Carnot then explains how we can obtain power, i. e. “work”. It also acts as a cooler and hence can also act as a Refrigerator, the previous image shows the original piston-and-cylinder diagram used by Carnot in discussing his ideal engines. The figure at right shows a diagram of a generic heat engine. In the diagram, the “working body”, an introduced by Clausius in 1850. Carnot had postulated that the body could be any substance capable of expansion, such as vapor of water, vapor of alcohol, vapor of mercury. The output work W here is the movement of the piston as it is used to turn a crank-arm, Carnot defined work as “weight lifted through a height”. The Carnot cycle when acting as a heat engine consists of the steps, Reversible isothermal expansion of the gas at the hot temperature. During this step the gas is allowed to expand and it work on the surroundings. The temperature of the gas does not change during the process, the gas expansion is propelled by absorption of heat energy Q1 and of entropy Δ S H = Q H / T H from the high temperature reservoir. For this step the piston and cylinder are assumed to be thermally insulated, the gas continues to expand, doing work on the surroundings, and losing an equivalent amount of internal energy. The gas expansion causes it to cool to the cold temperature, Reversible isothermal compression of the gas at the cold temperature, TC. Now the surroundings do work on the gas, causing an amount of heat energy Q2, once again the piston and cylinder are assumed to be thermally insulated
8.
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
9.
Engineer
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Engineers design materials, structures, and systems while considering the limitations imposed by practicality, regulation, safety, and cost. The word engineer is derived from the Latin words ingeniare and ingenium, the work of engineers forms the link between scientific discoveries and their subsequent applications to human and business needs and quality of life. His/her work is predominantly intellectual and varied and not of a mental or physical character. It requires the exercise of original thought and judgement and the ability to supervise the technical, he/she is thus placed in a position to make contributions to the development of engineering science or its applications. In due time he/she will be able to give authoritative technical advice, much of an engineers time is spent on researching, locating, applying, and transferring information. Indeed, research suggests engineers spend 56% of their time engaged in various information behaviours, Engineers must weigh different design choices on their merits and choose the solution that best matches the requirements. Their crucial and unique task is to identify, understand, Engineers apply techniques of engineering analysis in testing, production, or maintenance. Analytical engineers may supervise production in factories and elsewhere, determine the causes of a process failure and they also estimate the time and cost required to complete projects. Supervisory engineers are responsible for major components or entire projects, Engineering analysis involves the application of scientific analytic principles and processes to reveal the properties and state of the system, device or mechanism under study. Most engineers specialize in one or more engineering disciplines, numerous specialties are recognized by professional societies, and each of the major branches of engineering has numerous subdivisions. Civil engineering, for example, includes structural and transportation engineering and materials engineering include ceramic, metallurgical, mechanical engineering cuts across just about every discipline since its core essence is applied physics. Engineers also may specialize in one industry, such as vehicles, or in one type of technology. Several recent studies have investigated how engineers spend their time, that is, research suggests that there are several key themes present in engineers’ work, technical work, social work, computer-based work, information behaviours. Amongst other more detailed findings, a recent work sampling study found that engineers spend 62. 92% of their time engaged in work,40. 37% in social work. The time engineers spend engaged in activities is also reflected in the competencies required in engineering roles. There are many branches of engineering, each of which specializes in specific technologies, typically engineers will have deep knowledge in one area and basic knowledge in related areas. When developing a product, engineers work in interdisciplinary teams. For example, when building robots an engineering team will typically have at least three types of engineers, a mechanical engineer would design the body and actuators
10.
French Army
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The French Army, officially the Land Army is the land-based and largest component of the French Armed Forces. Along with the French Air Force, the French Navy and the National Gendarmerie, the current Chief of Staff of the French Army is General Jean-Pierre Bosser, a direct subordinate of the Chief of the Defence Staff. All soldiers are considered professionals following the suspension of conscription, voted in parliament in 1997, as of 2014, the French Army employed 111,628 personnel. In addition, the element of the French Army consisted of 15,453 personnel of the Operational Reserve. The Kings of France needed reliable troops during and after the Hundred Years War and these units of troops were raised by issuing ordonnances to govern their length of service, composition and payment. These Compagnies dordonnance formed the core of the Gendarme Cavalry into the sixteenth century, stationed throughout France and summoned into larger armies as needed. There was also made for Francs-archers units of bowmen and foot soldiers raised from the non-noble classes. The bulk of the infantry for warfare was still provided by urban or provincial militias, raised from an area or city to fight locally and named for their recruiting grounds. Gradually these units became more permanent, and in 1480s Swiss instructors were recruited and these men would be paid and contracted and receive training. Henry II further regularised the French army by forming standing Infantry regiments to replace the Militia structure, the first of these the Régiments de Picardie, Piémont, Navarre and Champagne were called the Les Vieux Corps. It was normal policy to disband regiments after a war was over as a cost saving measure with the Vieux Corps and the Kings own Household Troops the Maison du Roi being the only survivors. Regiments could be raised directly by the King and so called after the region in which they were raised, or by the nobility and so called after the noble or his appointed colonel. In 1684 there was a reorganisation of the French infantry and again in 1701 to fit in with Louis XIVs plans. This reshuffle created many of the regiments of the French Army and standardised their equipment. The army of the Sun King tended to wear coats with coloured linings. There were exceptions and the troops, recruited from outside France. In addition to these regiments of the line the Maison du Roi provided several elite units, the Swiss Guards, French Guards, the revolution split the army with the main mass losing most of its officers to aristocratic flight or guillotine and becoming demoralised and ineffective. The French Guard joined the revolt and the Swiss Guards were massacred during the storming of the Tuileries palace, under Napoleon I, the French Army conquered most of Europe during the Napoleonic Wars
11.
Rudolf Clausius
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Rudolf Julius Emanuel Clausius, was a German physicist and mathematician and is considered one of the central founders of the science of thermodynamics. By his restatement of Sadi Carnots principle known as the Carnot cycle and his most important paper, On the Moving Force of Heat, published in 1850, first stated the basic ideas of the second law of thermodynamics. In 1865 he introduced the concept of entropy, in 1870 he introduced the virial theorem which applied to heat. Clausius was born in Köslin in the Province of Pomerania in Prussia and his father was a Protestant pastor and school inspector, and Rudolf studied in the school of his father. After a few years, he went to the Gymnasium in Stettin, Clausius graduated from the University of Berlin in 1844 where he studied mathematics and physics with, among others, Gustav Magnus, Peter Gustav Lejeune Dirichlet and Jakob Steiner. He also studied history with Leopold von Ranke, during 1847, he got his doctorate from the University of Halle on optical effects in the Earths atmosphere. He then became professor of physics at the Royal Artillery and Engineering School in Berlin, in 1855 he became professor at the ETH Zürich, the Swiss Federal Institute of Technology in Zürich, where he stayed until 1867. During that year, he moved to Würzburg and two later, in 1869 to Bonn. In 1870 Clausius organized a corps in the Franco-Prussian War. He was wounded in battle, leaving him with a lasting disability and he was awarded the Iron Cross for his services. His wife, Adelheid Rimpham, died in childbirth in 1875 and he continued to teach, but had less time for research thereafter. In 1886 he married Sophie Sack, and then had another child, two years later, on 24 August 1888, he died in Bonn, Germany. Clausiuss PhD thesis concerning the refraction of light proposed that we see a blue sky during the day, later, Lord Rayleigh would show that it was in fact due to the scattering of light, but regardless, Clausius used a far more mathematical approach than some have used. His most famous paper, Über die bewegende Kraft der Wärme was published in 1850, in this paper, he showed that there was a contradiction between Carnots principle and the concept of conservation of energy. Clausius restated the two laws of thermodynamics to overcome this contradiction and this paper made him famous among scientists. Clausius most famous statement of the law of thermodynamics was published in German in 1854. During 1857, Clausius contributed to the field of kinetic theory after refining August Krönigs very simple model to include translational, rotational and vibrational molecular motions. In this same work he introduced the concept of Mean free path of a particle, Clausius deduced the Clausius–Clapeyron relation from thermodynamics
12.
William Thomson, 1st Baron Kelvin
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William Thomson, 1st Baron Kelvin, OM, GCVO, PC, FRS, FRSE was a Scots-Irish mathematical physicist and engineer who was born in Belfast in 1824. He worked closely with mathematics professor Hugh Blackburn in his work and he also had a career as an electric telegraph engineer and inventor, which propelled him into the public eye and ensured his wealth, fame and honour. For his work on the telegraph project he was knighted in 1866 by Queen Victoria. He had extensive maritime interests and was most noted for his work on the mariners compass, absolute temperatures are stated in units of kelvin in his honour. He was ennobled in 1892 in recognition of his achievements in thermodynamics and he was the first British scientist to be elevated to the House of Lords. The title refers to the River Kelvin, which close by his laboratory at the University of Glasgow. His home was the red sandstone mansion Netherhall, in Largs. William Thomsons father, James Thomson, was a teacher of mathematics and engineering at Royal Belfast Academical Institution, James Thomson married Margaret Gardner in 1817 and, of their children, four boys and two girls survived infancy. Margaret Thomson died in 1830 when William was six years old, William and his elder brother James were tutored at home by their father while the younger boys were tutored by their elder sisters. James was intended to benefit from the share of his fathers encouragement, affection. In 1832, his father was appointed professor of mathematics at Glasgow, the Thomson children were introduced to a broader cosmopolitan experience than their fathers rural upbringing, spending mid-1839 in London and the boys were tutored in French in Paris. Mid-1840 was spent in Germany and the Netherlands, language study was given a high priority. His sister, Anna Thomson, was the mother of James Thomson Bottomley FRSE, Thomson had heart problems and nearly died when he was 9 years old. In school, Thomson showed a keen interest in the classics along with his natural interest in the sciences, at the age of 12 he won a prize for translating Lucian of Samosatas Dialogues of the Gods from Latin to English. In the academic year 1839/1840, Thomson won the prize in astronomy for his Essay on the figure of the Earth which showed an early facility for mathematical analysis. Throughout his life, he would work on the problems raised in the essay as a strategy during times of personal stress. On the title page of this essay Thomson wrote the lines from Alexander Popes Essay on Man. These lines inspired Thomson to understand the world using the power and method of science, Go
13.
Hippolyte Carnot
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Lazare Hippolyte Carnot was a French statesman. Hippolyte Carnot was born at Saint-Omer, Pas-de-Calais, after the final defeat of Napoleon in 1815, his father went into exile. Hippolyte Carnot lived at first in exile with his father, returning to France only in 1823 and he paid several visits to Britain and travelled in other countries of Europe. On 24 February 1848 he pronounced in favour of the republic and he opposed purely secular schools, holding that the minister and the schoolmaster are the two columns on which rests the edifice of the republic. By this attitude he alienated both the Right and the Republicans of the Extreme Left, and was forced to resign on 5 July 1848 and he was one of those who protested against the coup détat of 2 December 1851 but was not proscribed by Louis Napoleon. He refused to sit in the Corps Législatif until 1864, in not to have to take the oath to the emperor. From 1864 to 1869 he was in the opposition, taking a very active part. He was defeated at the election of 1869, on 8 February 1871 he was named deputy for the Seine-et-Oise département, and participated in the drawing up of the Constitutional Laws of 1875. On 16 December 1875 he was named by the National Assembly senator for life and he died three months after the election of his elder son, Marie François Sadi Carnot, to the presidency of the republic. He had published Le Ministère de lInstruction Publique et des Cultes, depuis le 24 février jusquau 5 juillet 1848, Mémoires sur Carnot par son fils and he was made a member of the Academy of Sciences in 1895. Attribution This article incorporates text from a now in the public domain, Chisholm, Hugh, ed. Carnot. Vermorel, Les Hommes de 1848, Spuller, Histoire parlementaire de la Seconde Republique, Pierre de La Gorce, Histoire du Second Empire
14.
Lazare Carnot
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Lazare Nicolas Marguerite, Count Carnot was a French politician, engineer, freemason and mathematician. He was known as the Organizer of Victory in the French Revolutionary Wars, born on May 13,1753 in the village of Nolay, Côte-dOr, Carnot was the son of local judge and royal notary, Claude Carnot and his wife, Marguerite Pothier. He was the second oldest of eighteen children, at the age of fourteen, Lazare and his brother were enrolled at the Collège d’Autun, in Burgundy where he focused on the study of philosophy and the classics. He held a belief in stoic philosophy and was deeply influenced by Roman civilization. When he turned fifteen, he left the Collège d’Autun to strengthen his philosophical knowledge, during his short time with them, he studied logic, mathematics and theology under the Abbe Bison. Here, he was enrolled in M. de Longpres pension school in 1770 until he was ready to enter one of two engineering and artillery schools in Paris. A year later, in February of 1771, he was ranked the third highest among twelve who were out of his class of more than one hundred who took the entrance exams. It was at point when he entered the Mézières School of Engineering appointed as second lieutenant. Studies at the Mézières included geometry, mechanics, geometrical designing, geography, hydraulics, on January 1,1773, he graduated the school ranked as first lieutenant. It was here where he met and studied with Benjamin Franklin and at the age of twenty, at this moment, he made a name for himself both in the line of theoretical engineering and in his work in the field of fortifications. While in the army, he continued his study of mathematics and this publication earned him the honor of admittance to a literary society. In that same year, he received a promotion to the rank of captain. At the outbreak of the French Revolution in 1789, Carnot entered political life and he became a delegate to the Legislature in 1791. While a member of the Legislative Assembly, Carnot was elected to the Committee for Public Instruction, after the Legislative Assembly was dissolved, Carnot was elected to the National Convention in 1792. He spent the last few months of 1792 on a mission to Bayonne, upon returning to Paris, Carnot voted for the death of King Louis XVI, although he had been absent for the debates surrounding the king’s trial. On 14 August 1793 Carnot was elected to the Committee of Public Safety, with the establishment of the Directory in 1795, Carnot became one of the five initial directors. For the first year, the Directors did well working harmoniously together as well as with the Councils, Carnot and Barthélemy supported concessions to end the war, and hoped to oust the triumvirate and replace them with more conservative men. Carnot took refuge in Geneva, and there in 1797 issued his La métaphysique du calcul infinitésimal, the creation of the French Revolutionary Army was largely due to his powers of organization and enforcing discipline
15.
Marie-Adolphe Carnot
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Marie Adolphe Carnot was a French chemist, mining engineer and politician. He came from a family, his father, Hippolyte Carnot, and brother, Marie François Sadi Carnot, were politicians. He was born in Paris and studied at the École Polytechnique and he became a member of the Corps des mines, and from 1864 to 1867, served as a mining engineer in Limoges. From 1868 to 1877 he was a professor of preparatory courses and general chemistry at the École des Mines in Paris, in 1881 he was appointed Chief Engineer of Mines, and in 1894, was named Inspector General of Mines. He became director of the École des Mines in 1901, a post he held until 1907, aside from administrative work and teaching and training many engineers, he wrote a treatise on the chemical analysis of minerals and pursued research. The uranium ore carnotite is named after him and he was honoured with membership of the Académie dAgriculture and Académie des sciences, and was made a Commander of the Légion dhonneur. He simultaneously pursued a political career
16.
Military engineering
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Military engineering is loosely defined as the art and practice of designing and building military works and maintaining lines of military transport and communications. Military engineers are responsible for logistics behind military tactics. Modern military engineering differs from civil engineering, in the 20th and 21st centuries, military engineering also includes other engineering disciplines such as mechanical and electrical engineering techniques. According to NATO, military engineering is that engineer activity undertaken, regardless of component or service, Military engineering does not encompass the activities undertaken by those engineers who maintain, repair and operate vehicles, vessels, aircraft, weapon systems and equipment. Military engineering is a subject taught in military academies or schools of military engineering. The construction and demolition tasks related to engineering are usually performed by military engineers including soldiers trained as sappers or pioneers. In modern armies, soldiers trained to perform such tasks while well forward in battle, the word engineer was initially used in the context of warfare, dating back to 1325 when engine’er referred to a constructor of military engines. In this context, engine referred to a machine, i. e. A mechanical contraption used in war, in its place, the term military engineering has come to be used. Modern military engineering can be divided into three main tasks or fields, combat engineering, strategic support, and ancillary support, combat engineering is associated with engineering on the battlefield. Combat engineers are responsible for increasing mobility on the front lines of war such as digging trenches, strategic support is associated with providing service in communication zones such as the construction of airfields and the improvement and upgrade of ports, roads and railways communication. Ancillary support includes provision and distribution of maps as well as the disposal of unexploded warheads, Military engineers construct bases, airfields, roads, bridges, ports, and hospitals. During peacetime before modern warfare, military engineers took the role of civil engineers by participating in the construction of civil-works projects, nowadays, military engineers are almost entirely engaged in war logistics and preparedness. Combat engineers clear routes, repair airfields and harbours, bridge rivers all at top speed, the first civilization to have a dedicated force of military engineering specialists were the Romans, whose army contained a dedicated corps of military engineers known as architecti. This group was pre-eminent among its contemporaries, such military engineering feats would have been completely new, and probably bewildering and demoralizing, to the Gallic defenders. The best known of these Roman army engineers due to his writings surviving is Vitruvius, alexander the Great also used engineers in his army. In ancient times, military engineers were responsible for warfare and building field fortifications, temporary camps. The most notable engineers of ancient times were the Romans and Chinese, the Romans were responsible for constructing fortified wooden camps and paved roads for their legions
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.
Thermodynamics
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Thermodynamics is a branch of science concerned with heat and temperature and their relation to energy and work. The behavior of these quantities is governed by the four laws of thermodynamics, the laws of thermodynamics are explained in terms of microscopic constituents by statistical mechanics. Thermodynamics applies to a variety of topics in science and engineering, especially physical chemistry, chemical engineering. The initial application of thermodynamics to mechanical heat engines was extended early on to the study of chemical compounds, Chemical thermodynamics studies the nature of the role of entropy in the process of chemical reactions and has provided the bulk of expansion and knowledge of the field. Other formulations of thermodynamics emerged in the following decades, statistical thermodynamics, or statistical mechanics, concerned itself with statistical predictions of the collective motion of particles from their microscopic behavior. In 1909, Constantin Carathéodory presented a mathematical approach to the field in his axiomatic formulation of thermodynamics. A description of any thermodynamic system employs the four laws of thermodynamics that form an axiomatic basis, the first law specifies that energy can be exchanged between physical systems as heat and work. In thermodynamics, interactions between large ensembles of objects are studied and categorized, central to this are the concepts of the thermodynamic system and its surroundings. A system is composed of particles, whose average motions define its properties, properties can be combined to express internal energy and thermodynamic potentials, which are useful for determining conditions for equilibrium and spontaneous processes. With these tools, thermodynamics can be used to describe how systems respond to changes in their environment and this can be applied to a wide variety of topics in science and engineering, such as engines, phase transitions, chemical reactions, transport phenomena, and even black holes. This article is focused mainly on classical thermodynamics which primarily studies systems in thermodynamic equilibrium, non-equilibrium thermodynamics is often treated as an extension of the classical treatment, but statistical mechanics has brought many advances to that field. Guericke was driven to make a vacuum in order to disprove Aristotles long-held supposition that nature abhors a vacuum. Shortly after Guericke, the English physicist and chemist Robert Boyle had learned of Guerickes designs and, in 1656, in coordination with English scientist Robert Hooke, using this pump, Boyle and Hooke noticed a correlation between pressure, temperature, and volume. In time, Boyles Law was formulated, which states that pressure, later designs implemented a steam release valve that kept the machine from exploding. By watching the valve rhythmically move up and down, Papin conceived of the idea of a piston and he did not, however, follow through with his design. Nevertheless, in 1697, based on Papins designs, engineer Thomas Savery built the first engine, although these early engines were crude and inefficient, they attracted the attention of the leading scientists of the time. Black and Watt performed experiments together, but it was Watt who conceived the idea of the condenser which resulted in a large increase in steam engine efficiency. Drawing on all the work led Sadi Carnot, the father of thermodynamics, to publish Reflections on the Motive Power of Fire
19.
Reflections on the Motive Power of Fire
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Reflections on the Motive Power of Fire and on Machines Fitted to Develop that Power is a book published in 1824 by French physicist Sadi Carnot. The 118-page books French title was Réflexions sur la puissance motrice du feu et sur les machines propres à développer cette puissance and it is a significant publication in the history of thermodynamics about a generalized theory of heat engines. The book is considered the work of thermodynamics. It contains the outline of the second law of thermodynamics. Carnot stated that power is due to the fall of caloric from a hot to a cold body. The work was unnoticed until 1834 when French mining engineer Émile Clapeyron put it on a footing in his Memoir on the Motive Power of Heat. By 1849, thermo-dynamic, as a term, was used in William Thomsons paper An Account of Carnots Theory of the Motive Power of Heat. The Reflections contain a number of such as the Carnot cycle. Similar to how the Reflections was the precursor to the second law, analyzing a cycle, rather than an open system, is the correct way to analyze a heat engine. The concept of a reversible process
20.
Heat engine
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In thermodynamics, a heat engine is a system that converts heat or thermal energy—and chemical energy—to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher temperature to a lower state temperature. A heat source generates thermal energy that brings the working substance to the high temperature state, the working substance generates work in the working body of the engine while transferring heat to the colder sink until it reaches a low temperature state. During this process some of the energy is converted into work by exploiting the properties of the working substance. The working substance can be any system with a heat capacity. During this process, a lot of heat is lost to the surroundings, in general an engine converts energy to mechanical work. Heat engines distinguish themselves from other types of engines by the fact that their efficiency is limited by Carnots theorem. Since the heat source that supplies energy to the engine can thus be powered by virtually any kind of energy. Heat engines are often confused with the cycles they attempt to implement, typically, the term engine is used for a physical device and cycle for the model. In thermodynamics, heat engines are often modeled using an engineering model such as the Otto cycle. The theoretical model can be refined and augmented with data from an operating engine. Since very few implementations of heat engines exactly match their underlying thermodynamic cycles. In general terms, the larger the difference in temperature between the hot source and the sink, the larger is the potential thermal efficiency of the cycle. The efficiency of heat engines proposed or used today has a large range. 25% for most automotive gasoline engines 49% for a supercritical coal-fired power station such as the Avedøre Power Station, all these processes gain their efficiency from the temperature drop across them. Significant energy may be used for equipment, such as pumps. Heat engines can be characterized by their power, which is typically given in kilowatts per litre of engine displacement. The result offers an approximation of the power output of an engine
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Second law of thermodynamics
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The second law of thermodynamics states that the total entropy of an isolated system can only increase over time. It can remain constant in ideal cases where the system is in a state or undergoing a reversible process. The increase in entropy accounts for the irreversibility of processes. Historically, the law was an empirical finding that was accepted as an axiom of thermodynamic theory. Statistical thermodynamics, classical or quantum, explains the origin of the law. The second law has been expressed in many ways and its first formulation is credited to the French scientist Sadi Carnot in 1824, who showed that there is an upper limit to the efficiency of conversion of heat to work in a heat engine. The first law of thermodynamics provides the definition of internal energy, associated with all thermodynamic systems. The second law is concerned with the direction of natural processes and it asserts that a natural process runs only in one sense, and is not reversible. For example, heat flows spontaneously from hotter to colder bodies. Its modern definition is in terms of entropy, different notations are used for infinitesimal amounts of heat and infinitesimal amounts of entropy because entropy is a function of state, while heat, like work, is not. For an actually possible infinitesimal process without exchange of matter with the surroundings, the second law allows a distinguished temperature scale, which defines an absolute, thermodynamic temperature, independent of the properties of any particular reference thermometric body. These statements cast the law in general physical terms citing the impossibility of certain processes, the Clausius and the Kelvin statements have been shown to be equivalent. The historical origin of the law of thermodynamics was in Carnots principle. The Carnot engine is a device of special interest to engineers who are concerned with the efficiency of heat engines. Interpreted in the light of the first law, it is equivalent to the second law of thermodynamics. It states The efficiency of a quasi-static or reversible Carnot cycle depends only on the temperatures of the two reservoirs, and is the same, whatever the working substance. A Carnot engine operated in this way is the most efficient possible heat engine using those two temperatures, the German scientist Rudolf Clausius laid the foundation for the second law of thermodynamics in 1850 by examining the relation between heat transfer and work. The statement by Clausius uses the concept of passage of heat, as is usual in thermodynamic discussions, this means net transfer of energy as heat, and does not refer to contributory transfers one way and the other
22.
Entropy
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In statistical thermodynamics, entropy is a measure of the number of microscopic configurations Ω that a thermodynamic system can have when in a state as specified by some macroscopic variables. Formally, S = k B ln Ω, for example, gas in a container with known volume, pressure, and temperature could have an enormous number of possible configurations of the collection of individual gas molecules. Each instantaneous configuration of the gas may be regarded as random, Entropy may be understood as a measure of disorder within a macroscopic system. The second law of thermodynamics states that an isolated systems entropy never decreases, such systems spontaneously evolve towards thermodynamic equilibrium, the state with maximum entropy. Non-isolated systems may lose entropy, provided their environments entropy increases by at least that amount, since entropy is a function of the state of the system, a change in entropy of a system is determined by its initial and final states. This applies whether the process is reversible or irreversible, however, irreversible processes increase the combined entropy of the system and its environment. The above definition is called the macroscopic definition of entropy because it can be used without regard to any microscopic description of the contents of a system. The concept of entropy has found to be generally useful and has several other formulations. Entropy was discovered when it was noticed to be a quantity that behaves as a function of state and it has the dimension of energy divided by temperature, which has a unit of joules per kelvin in the International System of Units. But the entropy of a substance is usually given as an intensive property—either entropy per unit mass or entropy per unit amount of substance. In statistical mechanics this reflects that the state of a system is generally non-degenerate. Understanding the role of entropy in various processes requires an understanding of how. It is often said that entropy is an expression of the disorder, or randomness of a system, the second law is now often seen as an expression of the fundamental postulate of statistical mechanics through the modern definition of entropy. In other words, in any natural process there exists an inherent tendency towards the dissipation of useful energy and he made the analogy with that of how water falls in a water wheel. This was an insight into the second law of thermodynamics. g. Clausius described entropy as the transformation-content, i. e. dissipative energy use and this was in contrast to earlier views, based on the theories of Isaac Newton, that heat was an indestructible particle that had mass. Later, scientists such as Ludwig Boltzmann, Josiah Willard Gibbs, henceforth, the essential problem in statistical thermodynamics, i. e. according to Erwin Schrödinger, has been to determine the distribution of a given amount of energy E over N identical systems. Carathéodory linked entropy with a definition of irreversibility, in terms of trajectories
23.
French Revolutionary Army
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The French Revolutionary Army was the French force that fought the French Revolutionary Wars from 1792 to 1802. These armies were characterised by their revolutionary fervour, their poor equipment, leading generals included Jourdan, Bonaparte, Masséna and Moreau. As a general description of French military forces during this period, reactionary Europe stood opposed, especially after the French king was executed. As a result, one of the first major elements of the French state to be restructured was the army, almost all of the ancien regime officer class had been drawn from the aristocracy. During the period preceding the overthrow of the Monarchy, large numbers of officers left their regiments. Between 15 September and 1 December 1791 alone 2,160 officers of the army fled France eventually to join the émigré army of Louis Joseph. Of those who stayed numbers were either imprisoned or killed during the Reign of Terror, the small remaining cadre of officers were promoted swiftly, this meant that the majority of the Revolutionary officers were far younger than their Monarchist counterparts. Revolutionary fervour, along with calls to save the new regime, the desperate situation meant that these men were quickly inducted into the army. The transformation of the Army was best seen in the officer corps, before the revolution 90% had been aristocrats, compared to only 3% in 1794. Revolutionary fervor was high, and was monitored by the Committee of Public Safety. Indeed, some generals deserted, others were removed or executed, the government demanded that soldiers be loyal to the government in Paris, not to their generals. Officially, the Revolutionary Armies were operating along the set down in the 1791 Reglement. The 1791 Reglement laid down several complex maneuvers, maneuvers which demanded well trained soldiers, officers. The Revolutionary Army was lacking in all three of these areas, and as a result the early efforts to conform to the 1791 Reglement were met with disaster, the untrained troops could not perform the complex maneuvers required, unit cohesion was lost and defeat was ensured. Realizing that the army was not capable of conforming with the 1791 Reglement, many eminent French military thinkers had been clamoring for change decades before. In the period following the performance of the French Army during the Seven Years War. In the 1770s, some commanders, among them the brilliant duc de Broglie performed exercises testing these tactics, de Broglie decided that lordre profond worked best when it was supported by artillery and large numbers of skirmishers. Despite these exercises, lordre mince had strong and powerful supporters in the Royal Armée Française, the French struck first, with an invasion of the Austrian Netherlands proposed by foreign minister Charles François Dumouriez
24.
Saadi Shirazi
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Abū-Muhammad Muslih al-Dīn bin Abdallāh Shīrāzī, better known by his pen-name Saadi, also known as Saadi of Shiraz, was one of the major Persian poets and literary men of the medieval period. He is not only famous in Persian-speaking countries, but has been quoted in western sources as well and he is recognized for the quality of his writings and for the depth of his social and moral thoughts. Saadi is widely recognized as one of the greatest poets of the literary tradition. 1210, his father died when he was a child and he narrates memories of going out with his father as a child during festivities. In his youth, Saadi experienced poverty and hardship and left his native town for Baghdad to pursue a better education. As a young man he enrolled at the Nizamiyya University, where he studied in Islamic sciences, law, governance, history, Arabic literature, and Islamic theology. The unsettled conditions following the Mongol invasion of Khwarezm and Iran led him to wander for thirty years abroad through Anatolia, Syria, Egypt, in his writings he mentions the qadis, muftis of Al-Azhar, the grand bazaar, music and art. At Halab, Saadi joins a group of Sufis who had fought arduous battles against the Crusaders, Saadi was captured by Crusaders at Acre where he spent seven years as a slave digging trenches outside its fortress. He was later released after the Mamluks paid ransom for Muslim prisoners being held in Crusader dungeons, Saadi visited Jerusalem and then set out on a pilgrimage to Mecca and Medina. It is believed that he may have also visited Oman and other lands in the south of the Arabian Peninsula, because of the Mongol invasions he was forced to live in desolate areas and met caravans fearing for their lives on once-lively silk trade routes. Saadi lived in isolated refugee camps where he met bandits, Imams, men who owned great wealth or commanded armies, intellectuals. While Mongol and European sources gravitated to the potentates and courtly life of Ilkhanate rule and he sat in remote tea houses late into the night and exchanged views with merchants, farmers, preachers, wayfarers, thieves, and Sufi mendicants. For twenty years or more, he continued the same schedule of preaching, advising, Saadis works reflect upon the lives of ordinary Iranians suffering displacement, agony and conflict during the turbulent times of the Mongol invasion. Saadi mentions honey-gatherers in Azarbaijan, fearful of Mongol plunder and he finally returns to Persia where he meets his childhood companions in Isfahan and other cities. At Khorasan Saadi befriends a Turkic Emir named Tughral, Saadi joins him and his men on their journey to Sindh where he meets Pir Puttur, a follower of the Persian Sufi grand master Shaikh Usman Marvandvi. He also refers in his writings about his travels with a Turkic Amir named Tughral in Sindh, India, Tughral later enters service of the wealthy Delhi Sultanate, and Saadi is invited to Delhi and later visits the Vizier of Gujarat. During his stay in Gujarat, Saadi learns more about the Hindus and visits the temple of Somnath. Saadi came back to Shiraz before 1257 CE /655 AH, Saadi has mourned in his poetry the fall of Abbasid Caliphate and Baghdads destruction by Mongol invaders led by Hulagu in February 1258
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President of France
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The President of the French Republic, is the executive head of state of the French Fifth Republic. The powers, functions and duties of prior presidential offices, and their relation with the prime minister, the current President of France is François Hollande, who took office on 15 May 2012. Hollande has announced that he stand down in the upcoming 2017 French presidential election. President Chirac was first elected in 1995 and again in 2002, at that time, there was no limit on the number of terms, so Chirac could have run again, but chose not to. He was succeeded by Nicolas Sarkozy on 16 May 2007, following a further change, the Constitutional law on the Modernisation of the Institutions of the Fifth Republic,2008, a president cannot serve more than two consecutive terms. François Mitterrand and Jacques Chirac are the only Presidents to date who have served a two terms. In order to be admitted as a candidate, potential candidates must receive signed nominations from more than 500 elected officials. These officials must be from at least 30 départements or overseas collectivities, furthermore, each official may nominate only one candidate. There are exactly 45,543 elected officials, including 33,872 mayors, spending and financing of campaigns and political parties are highly regulated. There is a cap on spending, at approximately 20 million euros, if the candidate receives less than 5% of the vote, the government funds €8,000,000 to the party. Advertising on TV is forbidden but official time is given to candidates on public TV, an independent agency regulates election and party financing. After the president is elected, he or she goes through an investiture ceremony called a passation des pouvoirs. The French Fifth Republic is a semi-presidential system, unlike many other European presidents, the French President is quite powerful. The president holds the nations most senior office, and outranks all other politicians, the presidents greatest power is his/her ability to choose the prime minister. When the majority of the Assembly has opposite political views to that of the president, when the majority of the Assembly sides with them, the President can take a more active role and may, in effect, direct government policy. The prime minister is then the choice of the President. This device has been used in recent years by François Mitterrand, Jacques Chirac, since 2002, the mandate of the president and the Assembly are both 5 years and the two elections are close to each other. Therefore, the likelihood of a cohabitation is lower, among the powers of the government, The president promulgates laws
26.
Michel Chasles
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Michel Floréal Chasles was a French mathematician. He was born at Épernon in France and studied at the École Polytechnique in Paris under Siméon Denis Poisson, in the War of the Sixth Coalition he was drafted to fight in the defence of Paris in 1814. After the war, he gave up on a career as an engineer or stockbroker in order to pursue his mathematical studies, in 1837 he published his Historical view of the origin and development of methods in geometry, a study of the method of reciprocal polars in projective geometry. The work gained him fame and respect and he was appointed Professor at the École Polytechnique in 1841. A second edition of his book was published in 1875, jakob Steiner had proposed Steiners conic problem of enumerating the number of conic sections tangent to each of five given conics, and had answered it incorrectly. Chasles developed a theory of characteristics that enabled the correct enumeration of the conics, in kinematics, Chasles description of a Euclidean motion in space as screw displacement was seminal to the development of the theories of dynamics of rigid bodies. Chasles was elected a Foreign Honorary Member of the American Academy of Arts, in 1865 he was awarded the Copley Medal. As described in A Treasury of Deception, by Michael Farquhar, included in this trove were letters from Alexander the Great to Aristotle, from Cleopatra to Julius Caesar, and from Mary Magdalene to a revived Lazarus, all in a fake medieval French. In 2004, the journal Critical Inquiry published a recently discovered 1871 letter written by Vrain-Lucas to Chasles, conveying Vrain-Lucass perspective on these events, Chasles name is one of the 72 names inscribed on the Eiffel Tower. Note sur les propriétés générales du système de deux corps semblables entreux, bulletin des Sciences Mathématiques, Astronomiques, Physiques et Chemiques. M. Chasles Aperçu historique sur lorigine et le développement des méthodes en géométrie, originally published by Hayez in Bruxelles, M. M. Chasles Traité des sectiones-coniques, Gauthier-Villars, from University of Michigan. M. Chasles Traité de Géométrie Supérieure, Gauthier-Villars, from Google, chasles–Cayley–Brill formula Chasles theorem Asteroid 18510 Chasles OConnor, John J. Robertson, Edmund F. Michel Chasles, MacTutor History of Mathematics archive, University of St Andrews. Michel Chasles at the Mathematics Genealogy Project
27.
Gaspard-Gustave de Coriolis
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Gustave de Coriolis was a French mathematician, mechanical engineer and scientist. He is best known for his work on the forces that are detected in a rotating frame of reference. He was the first to coin the term work for the transfer of energy by a force acting through a distance, Coriolis was born in Paris in 1792. In 1829, Coriolis published a textbook, Calcul de lEffet des Machines, in this period, the correct expression for kinetic energy, ½mv2, and its relation to mechanical work, became established. During the following years, Coriolis worked to extend the notions of kinetic energy, the first of his papers, Sur le principe des forces vives dans les mouvements relatifs des machines, was read to the Académie des Sciences. Three years later came the paper that would make his name famous, corioliss papers do not deal with the atmosphere or even the rotation of the Earth, but with the transfer of energy in rotating systems like waterwheels. Coriolis discussed the supplementary forces that are detected in a frame of reference. The second category contained the force that would bear his name. A detailed discussion may be found in Dugas, in 1835, he published a mathematical work on collisions of spheres, Théorie Mathématique des Effets du Jeu de Billard, considered a classic on the subject. Corioliss name began to appear in the literature at the end of the 19th century. Coriolis became professor of mechanics at the École Centrale des Arts et Manufactures in 1829, in 1838, he succeeded Dulong as Directeur des études in the École Polytechnique. He died in 1843 at the age of 51 in Paris and his name is one of the 72 names inscribed on the Eiffel Tower. Persson, A.1998 How do we understand the Coriolis Force,79, 1373–1385.374 KB PDF document of the above article OConnor, John J. Robertson, Edmund F. Gaspard-Gustave de Coriolis, MacTutor History of Mathematics archive, University of St Andrews. Sur les équations du mouvement relatif des systèmes de corps, online and analyzed on BibNum Sur le bruit du tonnerre, online and analyzed on BibNum
28.
Joseph Louis Gay-Lussac
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Joseph Louis Gay-Lussac was a French chemist and physicist. Gay-Lussac was born at Saint-Léonard-de-Noblat in the department of Haute-Vienne. The father of Joseph Louis Gay, Anthony Gay, son of a doctor, was a lawyer and prosecutor, and worked as a judge in Noblat Bridge. Father of two sons and three daughters, he owned much of the Lussac village and usually added the name of this hamlet of the Haute-Vienne to his name, towards the year 1803, father and son finally adopted the name Gay-Lussac. During the Revolution, on behalf of the Law of Suspects and he received his early education at the hands of the Catholic Abbey of Bourdeix, though later in life became an atheist. In the care of the Abbot of Dumonteil he began his education in Paris, Gay-Lussac narrowly avoided conscription and by the time of entry to the École Polytechnique his father had been arrested. Three years later, Gay-Lussac transferred to the École des Ponts et Chaussées, in 1802, he was appointed demonstrator to A. F. Fourcroy at the École Polytechnique, where in he became professor of chemistry. From 1808 to 1832, he was professor of physics at the Sorbonne, in 1821, he was elected a foreign member of the Royal Swedish Academy of Sciences. In 1831 he was elected to represent Haute-Vienne in the chamber of deputies and he was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1832. Gay-Lussac married Geneviève-Marie-Joseph Rojot in 1809 and he had first met her when she worked as a linen drapers shop assistant and was studying a chemistry textbook under the counter. He fathered five children, of whom the eldest became assistant to Justus Liebig in Giessen, some publications by Jules are mistaken as his fathers today since they share the same first initial. Gay-Lussac died in Paris, and his grave is there at Père Lachaise Cemetery and his name is one of the 72 names inscribed on the Eiffel Tower. 1802 – Gay-Lussac first formulated the law, Gay-Lussacs Law, stating if the mass. His work was preceded by that of Guillaume Amontons, who established the rough relation without the use of accurate thermometers. The law is written as p = k T, where k is a constant dependent on the mass and volume of the gas. 1804 – He and Jean-Baptiste Biot made a balloon ascent to a height of 7,016 metres in an early investigation of the Earths atmosphere. He wanted to collect samples of the air at different heights to record differences in temperature and moisture,1805 – Together with his friend and scientific collaborator Alexander von Humboldt, he discovered that the composition of the atmosphere does not change with decreasing pressure. They also discovered that water is formed by two parts of hydrogen and one part of oxygen,1808 – He was the co-discoverer of boron
29.
Napoleon
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Napoleon Bonaparte was a French military and political leader who rose to prominence during the French Revolution and led several successful campaigns during the French Revolutionary Wars. As Napoleon I, he was Emperor of the French from 1804 until 1814, Napoleon dominated European and global affairs for more than a decade while leading France against a series of coalitions in the Napoleonic Wars. He won most of these wars and the vast majority of his battles, one of the greatest commanders in history, his wars and campaigns are studied at military schools worldwide. Napoleons political and cultural legacy has ensured his status as one of the most celebrated and he was born Napoleone di Buonaparte in Corsica to a relatively modest family from the minor nobility. When the Revolution broke out in 1789, Napoleon was serving as an officer in the French army. Seizing the new opportunities presented by the Revolution, he rose through the ranks of the military. The Directory eventually gave him command of the Army of Italy after he suppressed a revolt against the government from royalist insurgents, in 1798, he led a military expedition to Egypt that served as a springboard to political power. He engineered a coup in November 1799 and became First Consul of the Republic and his ambition and public approval inspired him to go further, and in 1804 he became the first Emperor of the French. Intractable differences with the British meant that the French were facing a Third Coalition by 1805, in 1806, the Fourth Coalition took up arms against him because Prussia became worried about growing French influence on the continent. Napoleon quickly defeated Prussia at the battles of Jena and Auerstedt, then marched the Grand Army deep into Eastern Europe, France then forced the defeated nations of the Fourth Coalition to sign the Treaties of Tilsit in July 1807, bringing an uneasy peace to the continent. Tilsit signified the high watermark of the French Empire, hoping to extend the Continental System and choke off British trade with the European mainland, Napoleon invaded Iberia and declared his brother Joseph the King of Spain in 1808. The Spanish and the Portuguese revolted with British support, the Peninsular War lasted six years, featured extensive guerrilla warfare, and ended in victory for the Allies. The Continental System caused recurring diplomatic conflicts between France and its client states, especially Russia, unwilling to bear the economic consequences of reduced trade, the Russians routinely violated the Continental System and enticed Napoleon into another war. The French launched an invasion of Russia in the summer of 1812. The resulting campaign witnessed the collapse of the Grand Army, the destruction of Russian cities, in 1813, Prussia and Austria joined Russian forces in a Sixth Coalition against France. A lengthy military campaign culminated in a large Allied army defeating Napoleon at the Battle of Leipzig in October 1813, the Allies then invaded France and captured Paris in the spring of 1814, forcing Napoleon to abdicate in April. He was exiled to the island of Elba near Rome and the Bourbons were restored to power, however, Napoleon escaped from Elba in February 1815 and took control of France once again. The Allies responded by forming a Seventh Coalition, which defeated Napoleon at the Battle of Waterloo in June, the British exiled him to the remote island of Saint Helena in the South Atlantic, where he died six years later at the age of 51
30.
Hundred Days
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The Hundred Days marked the period between Napoleons return from exile on the island of Elba to Paris on 20 March 1815 and the second restoration of King Louis XVIII on 8 July 1815. This period saw the War of the Seventh Coalition, and includes the Waterloo Campaign, the phrase les Cent Jours was first used by the prefect of Paris, Gaspard, comte de Chabrol, in his speech welcoming the king back to Paris on 8 July. Napoleon returned while the Congress of Vienna was sitting, the French Revolutionary and Napoleonic Wars pitted France against various coalitions of other European nations nearly continuously from 1792 onward. The overthrow and subsequent public execution of Louis XVI in France had greatly disturbed other European leaders, rather than leading to Frances defeat, the wars allowed the revolutionary regime to expand beyond its borders and create client republics. The success of the French forces made an out of their best commander. In 1799, Napoleon staged a successful coup détat and became First Consul of the new French Consulate, five years later, he crowned himself Emperor Napoleon I. The rise of Napoleon troubled the other European powers as much as the revolutionary regime had. Despite the formation of new coalitions against him, Napoleons forces continued to conquer much of Europe, the tide of war began to turn after a disastrous French invasion of Russia in 1812 that resulted in the loss of much of Napoleons army. The following year, during the War of the Sixth Coalition, Coalition forces defeated the French in the Battle of Leipzig, following its victory at Leipzig, the Coalition vowed to press on to Paris and depose Napoleon. In the last week of February 1814, Prussian Field Marshal Gebhard Leberecht von Blücher advanced on Paris, the Battle of Reims went to Napoleon, but this victory was followed by successive defeats from increasingly overwhelming odds. Coalition forces entered Paris after the Battle of Montmartre on 30 March 1814, on 6 April 1814, Napoleon abdicated his throne, leading to the accession of Louis XVIII and the first Bourbon Restoration a month later. The defeated Napoleon was exiled to the island of Elba off the coast of Tuscany, Napoleon spent only nine months and 21 days in uneasy retirement on Elba, watching events in France with great interest as the Congress of Vienna gradually gathered. He had been escorted to Elba by Sir Neil Campbell, who remained in there while performing other duties in Italy. Equally threatening was the situation in Europe which had been stressed and exhausted during the previous decades of near constant warfare. The conflicting demands of major powers were for a time so exorbitant as to bring the Powers at the Congress of Vienna to the verge of war with each other. Thus every scrap of news reaching remote Elba looked favourable to Napoleon to retake power as he reasoned the news of his return would cause a popular rising as he approached. So threatening were the symptoms that the royalists at Paris and the plenipotentiaries at Vienna talked of deporting him to the Azores or to Saint Helena, at the Congress of Vienna the various participating nations had very different and conflicting goals. Tsar Alexander of Russia had expected to absorb much of Poland and to leave a Polish puppet state, the renewed Prussian state demanded all of the Kingdom of Saxony
31.
Bourbon Restoration
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The Bourbon Restoration was the period of French history following the fall of Napoleon in 1814 until the July Revolution of 1830. The brothers of executed Louis XVI of France reigned in highly conservative fashion, and they were nonetheless unable to reverse most of the changes made by the French Revolution and Napoleon. At the Congress of Vienna they were treated respectfully, but had to give up all the gains made since 1789. King Louis XVI of the House of Bourbon had been overthrown and executed during the French Revolution, a coalition of European powers defeated Napoleon in the War of the Sixth Coalition, ended the First Empire in 1814, and restored the monarchy to the brothers of Louis XVI. The Bourbon Restoration lasted from 6 April 1814 until the uprisings of the July Revolution of 1830. There was an interlude in spring 1815—the Hundred Days—when the return of Napoleon forced the Bourbons to flee France, when Napoleon was again defeated by the Seventh Coalition they returned to power in July. During the Restoration, the new Bourbon regime was a monarchy, unlike the absolutist Ancien Régime. The period was characterized by a conservative reaction, and consequent minor but consistent occurrences of civil unrest. It also saw the reestablishment of the Catholic Church as a power in French politics. The eras of the French Revolution and Napoleon brought a series of changes to France which the Bourbon Restoration did not reverse. First of all, France became highly centralized, with all decisions made in Paris, the political geography was completely reorganized and made uniform. France was divided more than 80 departments, which have endured into the 21st century. Each department had an administrative structure, and was tightly controlled by a prefect appointed by Paris. The Catholic Church lost all its lands and buildings during the Revolution, the bishop still ruled his diocese, and communicated with the pope through the government in Paris. Bishops, priests, nuns and other people were paid salaries by the state. All the old rites and ceremonies were retained, and the government maintained the religious buildings. The Church was allowed to operate its own seminaries and to some extent local schools as well, bishops were much less powerful than before, and had no political voice. However, the Catholic Church reinvented itself and put a new emphasis on personal religiosity that gave it a hold on the psychology of the faithful, education was centralized, with the Grand Master of the University of France controlling every element of the entire educational system from Paris
32.
Louis XVIII of France
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Louis XVIII, known as The Desired, was a monarch of the House of Bourbon who ruled as King of France from 1814 to 1824 except for a period in 1815 known as the Hundred Days. Until his accession to the throne of France, Louis held the title of Count of Provence as brother of King Louis XVI, on 21 September 1792, the National Convention abolished the monarchy and deposed King Louis XVI, who was later executed by guillotine. When the young Louis XVII, Louis XVIs son, died in prison in June 1795, during the French Revolution and Napoleonic era, Louis XVIII lived in exile in Prussia, the United Kingdom and Russia. When the Sixth Coalition finally defeated Napoleon in 1814, Louis was placed in what he, Napoleon escaped from his exile in Elba, however, and restored his French Empire. Louis XVIII fled and a Seventh Coalition declared war on the French Empire, defeated Napoleon, Louis XVIII ruled as king for slightly less than a decade. The Bourbon Restoration regime was a constitutional monarchy, as a constitutional monarch, Louis XVIIIs royal prerogative was reduced substantially by the Charter of 1814, Frances new constitution. Louis had no children, therefore, upon his death, the passed to his brother, Charles. Louis XVIII was the last French monarch to die while reigning, as his successor Charles X abdicated and both Louis Philippe I and Napoléon III were deposed. Louis Stanislas Xavier, styled Count of Provence from birth, was born on 17 November 1755 in the Palace of Versailles, the son of Louis, Dauphin of France and he was the grandson of the reigning King Louis XV. As a son of the Dauphin he was a Fils de France, Louis Stanislas was christened Louis Stanislas Xavier six months after his birth in accordance with Bourbon family tradition, being nameless before his baptism. By this act, he also a Knight of the Order of the Holy Spirit. The former died in 1761, leaving Louis Auguste as heir to their father until the Dauphins own premature death in 1765, the two deaths elevated Louis Stanislas to second in the line of succession, while Louis Auguste acquired the title Dauphin. Louis Stanislas found comfort in his governess, Madame de Marsan, Governess of the Children of France, as he was her favourite among his siblings. Louis Stanislas was taken away from his governess when he turned seven, Antoine de Quélen de Stuer de Caussade, Duke of La Vauguyon, a friend of his father, was named his governor. Louis Stanislas was an intelligent boy, excelling in classics and his education was of the same quality and consistency as that of his older brother, Louis Auguste, despite the fact that Louis Auguste was heir and Louis Stanislas was not. Louis Stanislas education was religious in nature, several of his teachers were men of the cloth. La Vauguyon drilled into young Louis Stanislas and his brothers the way he thought princes should know how to withdraw themselves, to like to work, and to know how to reason correctly. In the same month his household was founded, Louis was granted titles by his grandfather, Louis XV, Duke of Anjou, Count of Maine, Count of Perche
33.
Fortification
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Fortifications are military constructions or buildings designed for the defense of territories in warfare, and also used to solidify rule in a region during peace time. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs, the term is derived from the Latin fortis and facere. From very early history to modern times, walls have been a necessity for cities to survive in a changing world of invasion. Some settlements in the Indus Valley Civilization were the first small cities to be fortified, in ancient Greece, large stone walls had been built in Mycenaean Greece, such as the ancient site of Mycenae. A Greek Phrourion was a collection of buildings used as a military garrison. These construction mainly served the purpose of a tower, to guard certain roads, passes. Though smaller than a fortress, they acted as a border guard rather than a real strongpoint to watch. The art of setting out a camp or constructing a fortification traditionally has been called castramentation since the time of the Roman legions. Fortification is usually divided into two branches, permanent fortification and field fortification, there is also an intermediate branch known as semi-permanent fortification. Castles are fortifications which are regarded as being distinct from the fort or fortress in that they are a residence of a monarch or noble. Roman forts and hill forts were the antecedents of castles in Europe. The Early Middle Ages saw the creation of towns built around castles. Medieval-style fortifications were made obsolete by the arrival of cannons in the 14th century. Fortifications in the age of black powder evolved into much lower structures with greater use of ditches and earth ramparts that would absorb, Walls exposed to direct cannon fire were very vulnerable, so were sunk into ditches fronted by earth slopes. The arrival of explosive shells in the 19th century led to yet another stage in the evolution of fortification, steel-and-concrete fortifications were common during the 19th and early 20th centuries. However the advances in warfare since World War I have made large-scale fortifications obsolete in most situations. Demilitarized zones along borders are arguably another type of fortification, although a passive kind, many military installations are known as forts, although they are not always fortified. Larger forts may be called fortresses, smaller ones were known as fortalices
34.
Steam engine
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A steam engine is a heat engine that performs mechanical work using steam as its working fluid. Steam engines are combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as power, nuclear power or geothermal energy may be used. The ideal thermodynamic cycle used to analyze this process is called the Rankine cycle, in the cycle, water is heated and transforms into steam within a boiler operating at a high pressure. When expanded through pistons or turbines, mechanical work is done, the reduced-pressure steam is then exhausted to the atmosphere, or condensed and pumped back into the boiler. Specialized devices such as hammers and steam pile drivers are dependent on the steam pressure supplied from a separate boiler. The use of boiling water to mechanical motion goes back over 2000 years. The Spanish inventor Jerónimo de Ayanz y Beaumont obtained the first patent for an engine in 1606. In 1698 Thomas Savery patented a steam pump that used steam in direct contact with the water being pumped, Saverys steam pump used condensing steam to create a vacuum and draw water into a chamber, and then applied pressurized steam to further pump the water. Thomas Newcomens atmospheric engine was the first commercial steam engine using a piston. In 1781 James Watt patented an engine that produced continuous rotary motion. Watts ten-horsepower engines enabled a range of manufacturing machinery to be powered. The engines could be sited anywhere that water and coal or wood fuel could be obtained, by 1883, engines that could provide 10,000 hp had become feasible. The stationary steam engine was a key component of the Industrial Revolution, the aeolipile described by Hero of Alexandria in the 1st century AD is considered to be the first recorded steam engine. Torque was produced by steam jets exiting the turbine, in the Spanish Empire, the great inventor Jerónimo de Ayanz y Beaumont obtained a patent for the first steam engine in history in 1603. Thomas Savery, in 1698, patented the first practical, atmospheric pressure and it had no piston or moving parts, only taps. It was an engine, a kind of thermic syphon, in which steam was admitted to an empty container. The vacuum thus created was used to water from the sump at the bottom of the mine
35.
James Watt
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While working as an instrument maker at the University of Glasgow, Watt became interested in the technology of steam engines. He realised that contemporary engine designs wasted a great deal of energy by repeatedly cooling and reheating the cylinder, Watt introduced a design enhancement, the separate condenser, which avoided this waste of energy and radically improved the power, efficiency, and cost-effectiveness of steam engines. Eventually he adapted his engine to produce rotary motion, greatly broadening its use beyond pumping water, Watt attempted to commercialise his invention, but experienced great financial difficulties until he entered a partnership with Matthew Boulton in 1775. The new firm of Boulton and Watt was eventually highly successful, in his retirement, Watt continued to develop new inventions though none was as significant as his steam engine work. He developed the concept of horsepower, and the SI unit of power, James Watt was born on 19 January 1736 in Greenock, Renfrewshire, a seaport on the Firth of Clyde. His father was a shipwright, ship owner and contractor, and served as the towns chief baillie, while his mother, Agnes Muirhead, both were Presbyterians and strong Covenanters. Watts grandfather, Thomas Watt, was a teacher and baillie to the Baron of Cartsburn. Despite being raised by parents, he later on became a deist. Watt did not attend regularly, initially he was mostly schooled at home by his mother but later he attended Greenock Grammar School. He exhibited great manual dexterity, engineering skills and an aptitude for mathematics, while Latin, when he was eighteen, his mother died and his fathers health began to fail. Watt travelled to London to study instrument-making for a year, then returned to Scotland and he made and repaired brass reflecting quadrants, parallel rulers, scales, parts for telescopes, and barometers, among other things. Because he had not served at least seven years as an apprentice, Watt was saved from this impasse by the arrival from Jamaica of astronomical instruments bequeathed by Alexander Macfarlane to the University of Glasgow, instruments that required expert attention. Watt restored them to working order and was remunerated and these instruments were eventually installed in the Macfarlane Observatory. Subsequently three professors offered him the opportunity to set up a workshop within the university. It was initiated in 1757 and two of the professors, the physicist and chemist Joseph Black as well as the famed Adam Smith, at first he worked on maintaining and repairing scientific instruments used in the university, helping with demonstrations, and expanding the production of quadrants. In 1759 he formed a partnership with John Craig, an architect and businessman, to manufacture and sell a line of products including musical instruments and this partnership lasted for the next six years, and employed up to sixteen workers. One employee, Alex Gardner, eventually took over the business, in 1764, Watt married his cousin Margaret Miller, with whom he had five children, two of whom lived to adulthood, James Jr. and Margaret. His wife died in childbirth in 1772, in 1777 he was married again, to Ann MacGregor, daughter of a Glasgow dye-maker, with whom he had two children, Gregory, who became a geologist and mineralogist, and Janet
36.
Conservation of energy
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In physics, the law of conservation of energy states that the total energy of an isolated system remains constant—it is said to be conserved over time. Energy can neither be created nor destroyed, rather, it transforms from one form to another, for instance, chemical energy can be converted to kinetic energy in the explosion of a stick of dynamite. A consequence of the law of conservation of energy is that a perpetual motion machine of the first kind cannot exist and that is to say, no system without an external energy supply can deliver an unlimited amount of energy to its surroundings. Ancient philosophers as far back as Thales of Miletus c.550 BCE had inklings of the conservation of some underlying substance of everything is made. However, there is no reason to identify this with what we know today as mass-energy. Empedocles wrote that in his system, composed of four roots, nothing comes to be or perishes, instead. In 1605, Simon Stevinus was able to solve a number of problems in statics based on the principle that perpetual motion was impossible. Essentially, he pointed out that the height a moving body rises is equal to the height from which it falls, and used this observation to infer the idea of inertia. The remarkable aspect of this observation is that the height that a moving body ascends to does not depend on the shape of the surface that the body is moving on. In 1669, Christian Huygens published his laws of collision, among the quantities he listed as being invariant before and after the collision of bodies were both the sum of their linear momentums as well as the sum of their kinetic energies. However, the difference between elastic and inelastic collision was not understood at the time and this led to the dispute among later researchers as to which of these conserved quantities was the more fundamental. In his Horologium Oscillatorium, he gave a much clearer statement regarding the height of ascent of a moving body, Huygens study of the dynamics of pendulum motion was based on a single principle, that the center of gravity of heavy objects cannot lift itself. The fact that energy is scalar, unlike linear momentum which is a vector. It was Leibniz during 1676–1689 who first attempted a mathematical formulation of the kind of energy which is connected with motion. Using Huygens work on collision, Leibniz noticed that in mechanical systems. He called this quantity the vis viva or living force of the system, the principle represents an accurate statement of the approximate conservation of kinetic energy in situations where there is no friction. Many physicists at that time, such as Newton, held that the conservation of momentum and it was later shown that both quantities are conserved simultaneously, given the proper conditions such as an elastic collision. In 1687, Isaac Newton published his Principia, which was organized around the concept of force and momentum
Chisholm, Hugh, ed. (1911). "Carnot, Sadi Nicolas Léonhard". Encyclopædia Britannica. 5 (11th ed.). Cambridge University Press.
Chisholm, Hugh, ed. (1911). "
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