An explosion is a rapid increase in volume and release of energy in an extreme manner with the generation of high temperatures and the release of gases. Supersonic explosions created by high explosives are known as detonations and travel via supersonic shock waves. Subsonic explosions are created by low explosives through a slower burning process known as deflagration. Explosions can occur in nature due to a large influx of energy. Most natural explosions arise from volcanic processes of various sorts. Explosive volcanic eruptions occur. Explosions occur as a result of impact events and in phenomena such as hydrothermal explosions. Explosions can occur outside of Earth in the universe in events such as supernova. Explosions occur during bushfires in eucalyptus forests where the volatile oils in the tree tops combust. Among the largest known explosions in the universe are supernovae, which results when a star explodes from the sudden starting or stopping of nuclear fusion gamma-ray bursts, whose nature is still in some dispute.
Solar flares are an example of a common explosion on the Sun, on most other stars as well. The energy source for solar flare activity comes from the tangling of magnetic field lines resulting from the rotation of the Sun's conductive plasma. Another type of large astronomical explosion occurs when a large meteoroid or an asteroid impacts the surface of another object, such as a planet; the most common artificial explosives are chemical explosives involving a rapid and violent oxidation reaction that produces large amounts of hot gas. Gunpowder was the first explosive to put to use. Other notable early developments in chemical explosive technology were Frederick Augustus Abel's development of nitrocellulose in 1865 and Alfred Nobel's invention of dynamite in 1866. Chemical explosions are initiated by an electric spark or flame in the presence of Oxygen. Accidental explosions may occur in rocket engines, etc.. A high current electrical fault can create an'electrical explosion' by forming a high energy electrical arc which vaporizes metal and insulation material.
This arc flash hazard is a danger to persons working on energized switchgear. Excessive magnetic pressure within an ultra-strong electromagnet can cause a magnetic explosion. A physical process, as opposed to chemical or nuclear, e.g. the bursting of a sealed or sealed container under internal pressure is referred to as an explosion. Examples include a simple tin can of beans tossed into a fire. Boiling liquid expanding vapor explosions are one type of mechanical explosion that can occur when a vessel containing a pressurized liquid is ruptured, causing a rapid increase in volume as the liquid evaporates. Note that the contents of the container may cause a subsequent chemical explosion, the effects of which can be more serious, such as a propane tank in the midst of a fire. In such a case, to the effects of the mechanical explosion when the tank fails are added the effects from the explosion resulting from the released propane in the presence of an ignition source. For this reason, emergency workers differentiate between the two events.
In addition to stellar nuclear explosions, a man-made nuclear weapon is a type of explosive weapon that derives its destructive force from nuclear fission or from a combination of fission and fusion. As a result a nuclear weapon with a small yield is more powerful than the largest conventional explosives available, with a single weapon capable of destroying an entire city. Explosive force is released in a direction perpendicular to the surface of the explosive. If a grenade is in mid air during the explosion, the direction of the blast will be 360°. In contrast, in a shaped charge the explosive forces are focused to produce a greater local effect; the speed of the reaction is what distinguishes an explosive reaction from an ordinary combustion reaction. Unless the reaction occurs rapidly, the thermally expanding gases will be moderately dissipated in the medium, with no large differential in pressure and there will be no explosion. Consider a wood fire; as the fire burns, there is the evolution of heat and the formation of gases, but neither is liberated enough to build up a sudden substantial pressure differential and cause an explosion.
This can be likened to the difference between the energy discharge of a battery, slow, that of a flash capacitor like that in a camera flash, which releases its energy all at once. The generation of heat in large quantities accompanies most explosive chemical reactions; the exceptions are called entropic explosives and include organic peroxides such as acetone peroxide. It is the rapid liberation of heat that causes the gaseous products of most explosive reactions to expand and generate high pressures; this rapid generation of high pressures of the released gas constitutes the explosion. The liberation of heat with insufficient rapidity will not cause an explosion. For example, although a unit mass of coal yields five times as much heat as a unit mass of nitroglycerin, the coal cannot be used as an explosive because the rate at which it yields this heat is quite slow. In fact, a substance which burns less may evolve more total heat than an explosive which detonates rapidly. In the form
American Academy of Arts and Sciences
The American Academy of Arts and Sciences is one of the oldest learned societies in the United States. Founded in 1780, the Academy is dedicated to honoring excellence and leadership, working across disciplines and divides, advancing the common good. Membership in the academy is achieved through a thorough petition and election process and has been considered a high honor of scholarly and societal merit since the academy was founded during the American Revolution by John Adams, John Hancock, James Bowdoin, others of their contemporaries who contributed prominently to the establishment of the new nation, its government, the United States Constitution. Today the Academy is charged with a dual function: to elect to membership the finest minds and most influential leaders, drawn from science, business, public affairs, the arts, from each generation, to conduct policy studies in response to the needs of society. Major Academy projects now have focused on higher education and research and cultural studies and technological advances, politics and the environment, the welfare of children.
Dædalus, the Academy's quarterly journal, is regarded as one of the world's leading intellectual journals. The Academy carries out nonpartisan policy research by bringing together scientists, artists, business leaders, other experts to make multidisciplinary analyses of complex social and intellectual topics; the Academy's current areas of work are Arts & Humanities, Democracy & Justice, Energy & Environment, Global Affairs, Science & Technology. David W. Oxtoby began his term as the organization’s President in January 2019. A chemist by training, he served as President of Pomona College from 2003 to 2017, he was elected a member of the American Academy in 2012. The Academy is headquartered in Massachusetts; the Academy was established by the Massachusetts legislature on May 4, 1780. Its purpose, as described in its charter, is "to cultivate every art and science which may tend to advance the interest, honor and happiness of a free and virtuous people." The sixty-two incorporating fellows represented varying interests and high standing in the political and commercial sectors of the state.
The first class of new members, chosen by the Academy in 1781, included Benjamin Franklin and George Washington as well as several international honorary members. The initial volume of Academy Memoirs appeared in 1785, the Proceedings followed in 1846. In the 1950s, the Academy launched its journal Daedalus, reflecting its commitment to a broader intellectual and socially-oriented program. Since the second half of the twentieth century, independent research has become a central focus of the Academy. In the late 1950s, arms control emerged as one of its signature concerns; the Academy served as the catalyst in establishing the National Humanities Center in North Carolina. In the late 1990s, the Academy developed a new strategic plan, focusing on four major areas: science and global security. In 2002, the Academy established a visiting scholars program in association with Harvard University. More than 75 academic institutions from across the country have become Affiliates of the Academy to support this program and other Academy initiatives.
The Academy has sponsored a number of awards and prizes, now numbering 11, throughout its history and has offered opportunities for fellowships and visiting scholars at the Academy. Charter members of the Academy are John Adams, Samuel Adams, John Bacon, James Bowdoin, Charles Chauncy, John Clarke, David Cobb, Samuel Cooper, Nathan Cushing, Thomas Cushing, William Cushing, Tristram Dalton, Francis Dana, Samuel Deane, Perez Fobes, Caleb Gannett, Henry Gardner, Benjamin Guild, John Hancock, Joseph Hawley, Edward Augustus Holyoke, Ebenezer Hunt, Jonathan Jackson, Charles Jarvis, Samuel Langdon, Levi Lincoln, Daniel Little, Elijah Lothrup, John Lowell, Samuel Mather, Samuel Moody, Andrew Oliver, Joseph Orne, Theodore Parsons, George Partridge, Robert Treat Paine, Phillips Payson, Samuel Phillips, John Pickering, Oliver Prescott, Zedekiah Sanger, Nathaniel Peaslee Sargeant, Micajah Sawyer, Theodore Sedgwick, William Sever, David Sewall, Stephen Sewall, John Sprague, Ebenezer Storer, Caleb Strong, James Sullivan, John Bernard Sweat, Nathaniel Tracy, Cotton Tufts, James Warren, Samuel West, Edward Wigglesworth, Joseph Willard, Abraham Williams, Nehemiah Williams, Samuel Williams, James Winthrop.
From the beginning, the membership and elected by peers, has included not only scientists and scholars, but writers and artists as well as representatives from the full range of professions and public life. Throughout the Academy's history, 10,000 fellows have been elected, including such notables as John Adams, Thomas Jefferson, John James Audubon, Joseph Henry, Washington Irving, Josiah Willard Gibbs, Augustus Saint-Gaudens, J. Robert Oppenheimer, Willa Cather, T. S. Eliot, Edward R. Murrow, Jonas Salk, Eudora Welty, Duke Ellington. International honorary members have included Jose Antonio Pantoja Hernandez, Leonhard Euler, Marquis de Lafayette, Alexander von Humboldt, Leopold von Ranke, Charles Darwin, Otto Hahn, Jawaharlal Nehru, Pablo Picasso, Liu Kuo-Sung, Lucian Michael Freud, Galina Ulanova, Werner Heisenberg, Alec Guinness and Sebastião Salgado. Astronomer Maria Mitchell was the first woman elected to the Academy, in 1848; the current membership encompasses over 5,700 members based across the United States and around the world.
Academy members include more than 60 Pulitzer Prize winners. The current membership is divided into five classes and twen
Prof Emil Clement Jungfleisch FRSE MIF was a French biochemist and pharmacist. He studied molecular dissymmetry, he was born in Paris on 21 December 1839. He studied at the Ecole Superieure de Pharmacie in Paris, he gained a BSc in Sciences in 1866. In 1869 he began assisting at his alma mater in Paris and in 1876 was made Professor of Organic Chemistry. In 1908 he succeeded Pierre Eugene Marcellin Berthelot as Professor of Chemistry at the College of France. In 1880 he was elected a member of the National Academy of Medicine and a member of the Academy of Sciences in 1909. In 1913 he was elected an Honorary Fellow of the Royal Society of Edinburgh, he died on 24 April 1916. He is buried in the 25th Division of Père Lachaise Cemetery in Paris. In 1910 he was sculpted in profile by Paul Richer. A copy of the plaque created is held at the Carnavalet Museum
Calvinism is a major branch of Protestantism that follows the theological tradition and forms of Christian practice set down by John Calvin and other Reformation-era theologians. Calvinists broke from the Roman Catholic Church in the 16th century. Calvinists differ from Lutherans on the real presence of Christ in the Eucharist, theories of worship, the use of God's law for believers, among other things; as declared in the Westminster and Second Helvetic confessions, the core doctrines are predestination and election. The term Calvinism can be misleading, because the religious tradition which it denotes has always been diverse, with a wide range of influences rather than a single founder. In the context of the Reformation, Huldrych Zwingli began the Reformed tradition in 1519 in the city of Zürich, his followers were labeled Zwinglians, consistent with the Catholic practice of naming heresy after its founder. Soon, Zwingli was joined by Martin Bucer, Wolfgang Capito, William Farel, Johannes Oecolampadius and other early Reformed thinkers.
The namesake of the movement, French reformer John Calvin, converted to the Reformed tradition from Roman Catholicism only in the late 1520s or early 1530s as it was being developed. The movement was first called referring to John Calvin, by Lutherans who opposed it. Many within the tradition find it either an indescriptive or an inappropriate term and would prefer the word Reformed to be used instead; some Calvinists prefer the term Augustinian-Calvinism since Calvin credited his theology to Augustine of Hippo. The most important Reformed theologians include John Calvin, Huldrych Zwingli, Martin Bucer, William Farel, Heinrich Bullinger, Peter Martyr Vermigli, Theodore Beza, John Knox. In the twentieth century, Abraham Kuyper, Herman Bavinck, B. B. Warfield, J. Gresham Machen, Karl Barth, Martyn Lloyd-Jones, Cornelius Van Til, Gordon Clark, R. C. Sproul were influential. Contemporary Reformed theologians include J. I. Packer, John MacArthur, Timothy J. Keller, David Wells, Michael Horton. Reformed churches may exercise several forms of ecclesiastical polity.
Calvinism is represented by Continental Reformed and Congregationalist traditions. The biggest Reformed association is the World Communion of Reformed Churches with more than 100 million members in 211 member denominations around the world. There are more conservative Reformed federations such as the World Reformed Fellowship and the International Conference of Reformed Churches, as well as independent churches. Calvinism is named after John Calvin, it was first used by a Lutheran theologian in 1552. It was a common practice of the Catholic Church to name; the term first came out of Lutheran circles. Calvin denounced the designation himself: They could attach us no greater insult than this word, Calvinism, it is not hard to guess. Despite its negative connotation, this designation became popular in order to distinguish Calvinists from Lutherans and from newer Protestant branches that emerged later; the vast majority of churches that trace their history back to Calvin do not use it themselves, since the designation "Reformed" is more accepted and preferred in the English-speaking world.
Moreover, these churches claim to be—in accordance with John Calvin's own words—"renewed accordingly with the true order of gospel". Since the Arminian controversy, the Reformed tradition—as a branch of Protestantism distinguished from Lutheranism—divided into two separate groups: Arminians and Calvinists. However, it is now rare to call Arminians a part of the Reformed tradition. While the Reformed theological tradition addresses all of the traditional topics of Christian theology, the word Calvinism is sometimes used to refer to particular Calvinist views on soteriology and predestination, which are summarized in part by the Five Points of Calvinism; some have argued that Calvinism as a whole stresses the sovereignty or rule of God in all things including salvation. First-generation Reformed theologians include Huldrych Zwingli, Martin Bucer, Wolfgang Capito, John Oecolampadius, Guillaume Farel; these reformers came from diverse academic backgrounds, but distinctions within Reformed theology can be detected in their thought the priority of scripture as a source of authority.
Scripture was viewed as a unified whole, which led to a covenantal theology of the sacraments of baptism and the Lord's Supper as visible signs of the covenant of grace. Another Reformed distinctive present in these theologians was their denial of the bodily presence of Christ in the Lord's supper; each of these theologians understood salvation to be by grace alone, affirmed a doctrine of particular election. Martin Luther and his successor Philipp Melanchthon were undoubtedly significant influences on these theologians, to a larger extent Reformed theologians; the doctrine of justification by faith alone was a direct inheritance from Luther. John Calvin, Heinrich Bullinger, Wolfgang Musculus, Peter Martyr Vermigli, Andreas Hyperius belong to the second generation of Reformed theologians. Calvin's Institutes of the Christian Religion was one of the most influential theologies of the era. Toward the middle of the 16th
The Grandes Écoles of France are higher education establishments that are outside the main framework of the French public university system. The Grandes Écoles are selective and prestigious institutions. Most Grandes Écoles select students for admission as graduates of bachelor degree programs, while others select students at the third year of undergraduate-level study, based chiefly on the student's national ranking in competitive written and oral exams. Candidates for the national exams have completed two years of dedicated preparatory classes for admission. Grandes écoles differ from public universities in France, which have a legal obligation to accept in the first year of undergraduate studies all candidates of the region who hold a corresponding baccalauréat.. Grande écoles do not have large student bodies: most give admission to few hundred students each year. Arts et Métiers ParisTech has the largest student population, with 6,000 students. Studying in some grandes écoles after passing the competitive exams is considered part of public service.
Students pay low or no fees, are paid monthly stipends by some institutions. They are committed to ten years of public service; the business schools charge higher fees. Economically disadvantaged students in grandes écoles may have access to grants and subsidies, just as they would at a public university; the phrase'Grande École' originated in 1794 after the French Revolution, when the National Convention created the École normale supérieure, the mathematician Gaspard Monge and Lazare Carnot created the École centrale des travaux publics and the abbot Henri Grégoire created the Conservatoire national des arts et métiers. The model was the military academy at Mézières, of which Monge was an alumnus; the system of competitive entry was a means to open up higher education to more candidates based on merit. Some schools included in the category have roots in the 17th and 18th century and are older than the phrase'Grande École', dated 1794, their forerunners were schools aimed at graduating civil servants, such as technical officers, mine supervisors and road engineers, shipbuilding engineers.
Five military engineering academies and graduate schools of artillery were established in the 17th century in France, such as the école de l'artillerie de Douai and the école du génie de Mézières, wherein mathematics and sciences were a major part of the curriculum taught by first-rank scientists such as Pierre-Simon Laplace, Charles Étienne Louis Camus, Étienne Bézout, Sylvestre-François Lacroix, Siméon Denis Poisson, Gaspard Monge. In 1802 Napoleon created the École Spéciale Militaire de Saint Cyr, considered a Grande École, although it trains only army officers. During the 19th century, a number of higher education Grandes écoles were established to support industry and commerce, such as École Nationale Supérieure des Mines de Saint-Étienne in 1816, Ecole Supérieure de Commerce de Paris, L'institut des sciences et industries du vivant et de l'environnement in 1826, École Centrale des Arts et Manufactures in 1829. Between 1832 and 1870, the Central School of Arts and Manufactures produced 3,000 engineers, served as a model for most of the industrialized countries.
Until 1864, a quarter of its students came from abroad. Conversely, the quality of French technicians astonished southeastern Europe, the Near East, Belgium; the system of grandes écoles expanded, enriched in 1826 by the Ecole des Eaux et Forêts at Nancy, the Ecole des Arts Industriels at Lille in 1854, the Ecole Centrale Lyonnaise in 1857, the National Institute of Agronomy, reconstituted in 1876 after a fruitless attempt between 1848 and 1855. The training of the lower grades of staff, who might today be called ‘production engineers’, was assured to an greater extent by the development of Ecoles d’Arts et métiers, of which the first was established at Châlons-sur-Marne in 1806 and the second at Angers in 1811, with a third at Aix-en-Provence in 1841; each had room for 300 pupils. There is no doubt that in the 1860s France had the best system of higher technical and scientific education in Europe. During the latter part of the 19th century and in the 20th century, more Grandes écoles were established for education in businesses as well as newer fields of science and technology, including Rouen Business School in 1871, Sciences Po Paris in 1872, École nationale supérieure des télécommunications, Hautes Études Commerciales, Ecole Supérieure des Sciences Economiques et Commerciales École supérieure d'électricité and Supaero.
Since France has had a unique dual higher education system, with small and middle-sized specialized graduate schools operating alongside the traditional university system. Some fields of study are nearly exclusive to one part of this dual system, such as medicine in universités only, o
The public domain consists of all the creative works to which no exclusive intellectual property rights apply. Those rights may have been forfeited, expressly waived, or may be inapplicable; the works of William Shakespeare and Beethoven, most early silent films, are in the public domain either by virtue of their having been created before copyright existed, or by their copyright term having expired. Some works are not covered by copyright, are therefore in the public domain—among them the formulae of Newtonian physics, cooking recipes, all computer software created prior to 1974. Other works are dedicated by their authors to the public domain; the term public domain is not applied to situations where the creator of a work retains residual rights, in which case use of the work is referred to as "under license" or "with permission". As rights vary by country and jurisdiction, a work may be subject to rights in one country and be in the public domain in another; some rights depend on registrations on a country-by-country basis, the absence of registration in a particular country, if required, gives rise to public-domain status for a work in that country.
The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". Although the term "domain" did not come into use until the mid-18th century, the concept "can be traced back to the ancient Roman Law, as a preset system included in the property right system." The Romans had a large proprietary rights system where they defined "many things that cannot be owned" as res nullius, res communes, res publicae and res universitatis. The term res nullius was defined as things not yet appropriated; the term res communes was defined as "things that could be enjoyed by mankind, such as air and ocean." The term res publicae referred to things that were shared by all citizens, the term res universitatis meant things that were owned by the municipalities of Rome. When looking at it from a historical perspective, one could say the construction of the idea of "public domain" sprouted from the concepts of res communes, res publicae, res universitatis in early Roman law.
When the first early copyright law was first established in Britain with the Statute of Anne in 1710, public domain did not appear. However, similar concepts were developed by French jurists in the 18th century. Instead of "public domain", they used terms such as publici juris or propriété publique to describe works that were not covered by copyright law; the phrase "fall in the public domain" can be traced to mid-19th century France to describe the end of copyright term. The French poet Alfred de Vigny equated the expiration of copyright with a work falling "into the sink hole of public domain" and if the public domain receives any attention from intellectual property lawyers it is still treated as little more than that, left when intellectual property rights, such as copyright and trademarks, expire or are abandoned. In this historical context Paul Torremans describes copyright as a, "little coral reef of private right jutting up from the ocean of the public domain." Copyright law differs by country, the American legal scholar Pamela Samuelson has described the public domain as being "different sizes at different times in different countries".
Definitions of the boundaries of the public domain in relation to copyright, or intellectual property more regard the public domain as a negative space. According to James Boyle this definition underlines common usage of the term public domain and equates the public domain to public property and works in copyright to private property. However, the usage of the term public domain can be more granular, including for example uses of works in copyright permitted by copyright exceptions; such a definition regards work in copyright as private property subject to fair-use rights and limitation on ownership. A conceptual definition comes from Lange, who focused on what the public domain should be: "it should be a place of sanctuary for individual creative expression, a sanctuary conferring affirmative protection against the forces of private appropriation that threatened such expression". Patterson and Lindberg described the public domain not as a "territory", but rather as a concept: "here are certain materials – the air we breathe, rain, life, thoughts, ideas, numbers – not subject to private ownership.
The materials that compose our cultural heritage must be free for all living to use no less than matter necessary for biological survival." The term public domain may be interchangeably used with other imprecise or undefined terms such as the "public sphere" or "commons", including concepts such as the "commons of the mind", the "intellectual commons", the "information commons". A public-domain book is a book with no copyright, a book, created without a license, or a book where its copyrights expired or have been forfeited. In most countries the term of protection of copyright lasts until January first, 70 years after the death of the latest living author; the longest copyright term is in Mexico, which has life plus 100 years for all deaths since July 1928. A notable exception is the United States, where every book and tale published prior to 1924 is in the public domain.