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Saturday, October 29, 2022

Spanish Golden Age

From Wikipedia, the free encyclopedia
 
In ictu oculi ("In the blink of an eye"), a vanitas by Juan de Valdés Leal
 
Façade of the Monastery of El Escorial

The Spanish Golden Age (Spanish: Siglo de Oro [ˈsiɣlo ðe ˈoɾo], "Golden Century") is a period of flourishing in arts and literature in Spain, coinciding with the political rise of the Spanish Empire under the Catholic Monarchs of Spain and the Spanish Habsburgs. The greatest patron of Spanish art and culture during this period was King Philip II (1556–1598), whose royal palace, El Escorial, invited the attention of some of Europe's greatest architects and painters such as El Greco, who infused Spanish art with foreign styles and helped create a uniquely Spanish style of painting. It is associated with the reigns of Isabella I, Ferdinand II, Charles V, Philip II, Philip III, and Philip IV, when Spain was one of the most powerful countries in the world.

The start of the Golden Age can be placed in 1492, with the end of the Reconquista, the voyages of Christopher Columbus to the New World, and the publication of Antonio de Nebrija's Grammar of the Castilian Language. It roughly ended with the Treaty of the Pyrenees in 1659 that ended the Franco-Spanish War of 1635 to 1659. Some extend the Golden Age up to 1681 with the death of the Pedro Calderón de la Barca, the last great writer of the age. It can be divided into a Plateresque/Renaissance period and the early part of the Spanish Baroque period.

Spanish literature blossomed as well, most famously demonstrated in the work of Miguel de Cervantes, the author of Don Quixote de la Mancha. Spain's most prolific playwright, Lope de Vega, wrote possibly one thousand plays during his lifetime, of which over four hundred survive to the present day. Diego Velázquez, regarded as one of the most influential painters of European history and a greatly respected artist in his own time, was patronized by King Philip IV and his chief minister, the Count-Duke of Olivares. The legacy of Diego Velázquez includes several portraits that demonstrate his style and skill.

Some of Spain's greatest music is regarded as having been written in the period. Such composers as Tomás Luis de Victoria, Cristóbal de Morales, Francisco Guerrero, Luis de Milán and Alonso Lobo helped to shape Renaissance music and the styles of counterpoint and polychoral music, and their influence lasted far into the Baroque period which resulted in a revolution of music.

The realms of Philip II of Spain
 
  Territories administered by the Council of Castile
  Territories administered by the Council of Aragon
  Territories administered by the Council of Portugal
  Territories administered by the Council of Italy
  Territories administered by the Council of the Indies
  Territories appointed to the Council of Flanders

Painting

Spain, in the time of the Italian Renaissance, had seen few great artists come to its shores. The Italian holdings and relationships made by Queen Isabella's husband and later Spain's sole monarch, Ferdinand of Aragon, launched a steady traffic of intellectuals across the Mediterranean between Valencia, Seville, and Florence. Luis de Morales, one of the leading exponents of Spanish Mannerist painting, retained a distinctly Spanish style in his work, reminiscent of medieval art. Spanish art, particularly that of Morales, contained a strong mark of mysticism and religion that was encouraged by the counter-reformation and the patronage of Spain's strongly Catholic monarchs and aristocracy. Spanish rule of Naples was important for making connections between Italian and Spanish art, with many Spanish administrators bringing Italian works back to Spain.

El Greco

Known for his unique expressionistic style that met with both puzzlement and admiration, El Greco (which means "The Greek") was not Spanish, having been born Domenikos Theotokopoulos in Crete. He studied the great Italian masters of his time—Titian, Tintoretto, and Michelangelo—when he lived in Italy from 1568 to 1577. According to legend, he asserted that he would paint a mural that would be as good as one of Michelangelo's, if one of the Italian artist's murals was demolished first. El Greco quickly fell out of favor in Italy, but soon found a new home in the city of Toledo, in central Spain. He was influential in creating a style based on impressions and emotion, featuring elongated fingers and vibrant color and brushwork. Uniquely, his works featured faces that captured expressions of sombre attitudes and withdrawal while still having his subjects bear witness to the terrestrial world. His paintings of the city of Toledo became models for a new European tradition in landscapes, and influenced the work of later Dutch masters. Spain at this time was an ideal environment for the Venetian-trained painter. Art was flourishing in the empire and Toledo was a great place to get commissions.

Las Meninas (1656, English: The Maids of Honour) by Diego Velázquez

Diego Velázquez

Diego Velázquez was born on June 6, 1599, in Seville. Both parents were from minor nobility. He was the oldest of six children. Velázquez is widely regarded as one of Spain's most important and influential artists. He was a court painter for King Philip IV and found an increasingly high demand for his portraits from statesmen, aristocrats, and clergymen across Europe. His portraits of the King, his chief minister, the Count-duke of Olivares, and the Pope himself demonstrated a belief in artistic realism and a style comparable to many of the Dutch masters. In the wake of the Thirty Years' War, Velázquez met the Marqués de Spinola and painted his famous Surrender of Breda celebrating Spinola's earlier victory. Spinola was struck by his ability to express emotion through realism in both his portraits and landscapes; his work in the latter, in which he launched one of European art's first experiments in outdoor lighting, became another lasting influence on Western painting. Velázquez's friendship with Bartolomé Esteban Murillo, a leading Spanish painter of the next generation, ensured the enduring influence of his artistic approach.

Velázquez's most famous painting is the celebrated Las Meninas, in which the artist includes himself as one of the subjects.

The Birth of the Virgin by Francisco de Zurbarán

Francisco de Zurbarán

The religious element in Spanish art, in many circles, grew in importance with the counter-reformation. The austere, ascetic, and severe work of Francisco de Zurbarán exemplified this thread in Spanish art, along with the work of composer Tomás Luis de Victoria. Philip IV actively patronized artists who agreed with his views on the counter-reformation and religion. The mysticism of Zurbarán's work—influenced by Saint Theresa of Avila—became a hallmark of Spanish art in later generations. Influenced by Michelangelo da Caravaggio and the Italian masters, Zurbarán devoted himself to an artistic expression of religion and faith. His paintings of St. Francis of Assisi, the immaculate conception, and the crucifixion of Christ reflected a third facet of Spanish culture in the seventeenth century, against the backdrop of religious war across Europe. Zurbarán broke from Velázquez's sharp realist interpretation of art and looked, to some extent, to the emotive content of El Greco and the earlier mannerist painters for inspiration and technique, though Zurbarán respected and maintained the lighting and physical nuance of Velázquez.

It is unknown whether Zurbarán had the opportunity to copy the paintings of Caravaggio; at any rate, he adopted Caravaggio's realistic use of chiaroscuro. The painter who may have had the greatest influence on his characteristically severe compositions was Juan Sánchez Cotán. Polychrome sculpture—which by the time of Zurbarán's apprenticeship had reached a level of sophistication in Seville that surpassed that of the local painters—provided another important stylistic model for the young artist; the work of Juan Martínez Montañés is especially close to Zurbarán's in spirit.

He painted directly from nature, and he made great use of the lay-figure in the study of draperies, in which he was particularly proficient. He had a special gift for white draperies; as a consequence, the houses of the white-robed Carthusians are abundant in his paintings. To these rigid methods, Zurbarán is said to have adhered throughout his career, which was prosperous, wholly confined to Spain, and varied by few incidents beyond those of his daily labour. His subjects were mostly severe and ascetic religious vigils, the spirit chastising the flesh into subjection, the compositions often reduced to a single figure. The style is more reserved and chastened than Caravaggio's, the tone of color often quite bluish. Exceptional effects are attained by the precisely finished foregrounds, massed out largely in light and shade.

Bartolomé Esteban Murillo

The Virgin of the Rosary (1675–80) by Bartolomé Esteban Murillo

Bartolomé Esteban Murillo began his art studies under Juan del Castillo in Seville. Murillo became familiar with Flemish painting; the great commercial importance of Seville at the time ensured that he was also subject to influences from other regions. His first works were influenced by Zurbarán, Jusepe de Ribera and Alonso Cano, and he shared their strongly realist approach. As his painting developed, his more important works evolved towards the polished style that suited the bourgeois and aristocratic tastes of the time, demonstrated especially in his Roman Catholic religious works.

In 1642, at the age of 26 he moved to Madrid, where he most likely became familiar with the work of Velázquez, and would have seen the work of Venetian and Flemish masters in the royal collections; the rich colors and softly modeled forms of his subsequent work suggest these influences. He returned to Seville in 1645. In that year, he painted thirteen canvases for the monastery of St. Francisco el Grande in Seville which gave his reputation a well-deserved boost. Following the completion of a pair of pictures for the Seville Cathedral, he began to specialise in the themes that brought him his greatest successes, Mary and child Jesus, and the Immaculate Conception.

After another period in Madrid, from 1658 to 1660, he returned to Seville, where he died. Here he was one of the founders of the Academia de Bellas Artes (Academy of Fine Arts), sharing its direction, in 1660, with the architect, Francisco Herrera the Younger. This was his period of greatest activity, and he received numerous important commissions, among them the altarpieces for the Augustinian monastery, the paintings for Santa María la Blanca (completed in 1665), and others.

Other significant painters

Sculpture

Entombment by Juan de Juni

Sculptors of the Renaissance

Sculptors of the Early Baroque period

Architecture

Palace of Charles V

Panoramic view of the lower level patio of the Palace

The Palace of Charles V is a Renacentist construction, located on the top of the hill of the Assabica, inside the Nasrid fortification of the Alhambra. It was commanded by Charles V, Holy Roman Emperor, who wished to establish his residence close to the Alhambra palaces. Although the Catholic Monarchs had already altered some rooms of the Alhambra after the conquest of the city in 1492, Charles V intended to construct a permanent residence befitting an emperor. The project was given to Pedro Machuca, an architect whose biography and influences are poorly understood. Even if accounts that place Machuca in the atelier of Michelangelo are accepted, at the time of the construction of the palace in 1527 the latter had yet to design the majority of his architectural works. At the time, Spanish architecture was immersed in the Plateresque style, still with traces of Gothic origin. Machuca built a palace corresponding stylistically to Mannerism, a mode still in its infancy in Italy.

El Escorial

The library of El Escorial

El Escorial is a historical residence of the king of Spain. It is one of the Spanish royal sites and functions as a monastery, royal palace, museum, and school. It is located about 45 kilometres (28 mi) northwest of the Spanish capital, Madrid, in the town of San Lorenzo de El Escorial. El Escorial comprises two architectural complexes of great historical and cultural significance: El Real Monasterio de El Escorial itself and La Granjilla de La Fresneda, a royal hunting lodge and monastic retreat about five kilometres away. These sites have a dual nature; that is to say, during the sixteenth and seventeenth centuries, they were places in which the temporal power of the Spanish monarchy and the ecclesiastical predominance of the Roman Catholic religion in Spain found a common architectural manifestation. El Escorial was, at once, a monastery and a Spanish royal palace. Originally a property of the Hieronymite monks, it is now a monastery of the Order of Saint Augustine.

Philip II of Spain, reacting to the Protestant Reformation sweeping through Europe during the sixteenth century, devoted much of his lengthy reign (1556–1598) and much of his seemingly inexhaustible supply of New World silver to stemming the Protestant tide sweeping through Europe, while simultaneously fighting the Islamic Ottoman Empire. His protracted efforts were, in the long run, partly successful. However, the same counter-reformational impulse had a much more benign expression, thirty years earlier, in Philip's decision to build the complex at El Escorial.

Philip engaged the Spanish architect, Juan Bautista de Toledo, to be his collaborator in the design of El Escorial. Juan Bautista had spent the greater part of his career in Rome, where he had worked on the basilica of St. Peter's, and in Naples, where he had served the king's viceroy, whose recommendation brought him to the king's attention. Philip appointed him architect-royal in 1559, and together they designed El Escorial as a monument to Spain's role as a center of the Christian world.

Plaza Mayor in Madrid

Plaza Mayor with the Casa de la Panadería to the left

The Plaza Mayor in Madrid was built during the Habsburg period is a central plaza in the city of Madrid, Spain. It is located only a few blocks away from another famous plaza, the Puerta del Sol. The Plaza Mayor is rectangular in shape, measuring 129 by 94 meters, and is surrounded by three-story residential buildings having 237 balconies facing the Plaza. It has a total of nine entranceways. The Casa de la Panadería, serving municipal and cultural functions, dominates the Plaza Mayor.

The origins of the Plaza go back to 1589 when Philip II of Spain asked Juan de Herrera, a renowned Renaissance architect, to discuss a plan to remodel the busy and chaotic area of the old Plaza del Arrabal. Juan de Herrera was the architect who designed the first project in 1581 to remodel the old Plaza del Arrabal but construction didn't start until 1617, during Philip III's reign. The king asked Juan Gómez de Mora to continue with the project, and he finished the porticoes in 1619. Nevertheless, the Plaza Mayor as we know it today is the work of the architect Juan de Villanueva who was entrusted with its reconstruction in 1790 after a spate of big fires. Giambologna's equestrian statue of Philip III dates to 1616, but it was not placed in the center of the square until 1848.

Granada Cathedral

Inner view of the cathedral

Unlike most cathedrals in Spain, construction of this cathedral had to await the acquisition of the Nasrid kingdom of Granada from its Muslim rulers in 1492; while its very early plans had Gothic designs, such as are evident in the Royal Chapel of Granada by Enrique Egas, the construction of the church in the main occurred at a time when Renaissance designs were supplanting the Gothic regnant in Spanish architecture of prior centuries. Foundations for the church were laid by the architect Egas starting from 1518 to 1523 atop the site of the city's main mosque; by 1529, Egas was replaced by Diego de Siloé who labored for nearly four decades on the structure from ground to cornice, planning the triforium and five naves instead of the usual three. Most unusually, he created a circular capilla mayor rather than a semicircular apse, perhaps inspired by Italian ideas for circular 'perfect buildings' (e.g. in Alberti's works). Within its structure the cathedral combines other orders of architecture. It took 181 years for the cathedral to be built.

Subsequent architects included Juan de Maena (1563–1571), followed by Juan de Orea (1571–1590), and Ambrosio de Vico (1590-?). In 1667 Alonso Cano, working with Gaspar de la Peña, altered the initial plan for the main façade, introducing Baroque elements. The magnificence of the building would be even greater, if the two large 81 meter towers foreseen in the plans had been built; however the project remained incomplete for various reasons, among them, financial.

The Granada Cathedral had been intended to become the royal mausoleum for Charles I of Spain, but Philip II of Spain moved the site for his father and subsequent kings to El Escorial outside of Madrid.

The main chapel contains two kneeling effigies of the Catholic King and Queen, Ferdinand and Isabel, by Pedro de Mena y Medrano. The busts of Adam and Eve were made by Alonso Cano. The Chapel of the Trinity has a marvelous retablo with paintings by El Greco, Alonso Cano, and José de Ribera (The Spagnoletto).

Cathedral of Valladolid

Cathedral of Valladolid's façade

The Cathedral of Valladolid, like all the buildings of the late Spanish Renaissance built by Herrera and his followers, is known for its purist and sober decoration, its style being the typical Spanish clasicismo, also called "Herrerian". Using classical and renaissance decorative motifs, Herrerian buildings are characterized by their extremely sober decorations, its formal austerity, and its like for monumentality.

The cathedral has its origins in a late gothic Collegiate which was started during the late 15th century, for before becoming capital of Spain Valladolid was not a bishopry see, and thus it lacked the right of building a cathedral. However, soon enough the Collegiate became obsolete due to the changes of taste of the day, and thanks to the newly established episcopal see in the city, the Town Council decided to build a cathedral that would shade similar constructions in neighbouring capitals.

Had the building been finished, it would have been one of the biggest cathedrals in Spain. When the building was started, Valladolid was the de facto capital of Spain, housing king Philip II and his court. However, due to strategical and geopolitical reasons, by the 1560s the capital was moved to Madrid, thus Valladolid losing its political and economical relevance. By the late sixteenth century, Valladolid's importance had been severely resented, and many of the monumental projects such as the cathedral, started during its former and glorious days, had to be modified due to the lack of proper finance. Thus, the building that nowadays stands could not be finished in all its splendour, and because of several additions built during the 17th and 18th centuries, it lacks the purported stylistical uniformity sought by Herrera. Indeed, although mainly faithful to the project of Juan de Herrera, the building would undergo many modifications, such as the addition to the top of the main façade, a work by Churriguera.

Significant architects

Renaissance and Plateresque period

Early Baroque period

Music

Tomás Luis de Victoria

Contemporary printing of the sheet music for Tomás Luis de Victoria's Officium Defunctorum.

Tomás Luis de Victoria, a Spanish composer of the sixteenth century, mainly of choral music, is widely regarded as one of the greatest Spanish classical composers. He joined the cause of Ignatius of Loyola in the fight against the Reformation and in 1575 became a priest. He lived for a short time in Italy, where he became acquainted with the polyphonic work of Giovanni Pierluigi da Palestrina. Like Zurbarán, Victoria mixed the technical qualities of Italian art with the religion and culture of his native Spain. He invigorated his work with emotional appeal and experimental, mystical rhythm and choruses. He broke from the dominant tendency among his contemporaries by avoiding complex counterpoint, preferring longer, simpler, less technical and more mysterious melodies, employing dissonance in ways that the Italian members of the Roman School shunned. He demonstrated considerable invention in musical thought by connecting the tone and emotion of his music to those of his lyrics, particularly in his motets. Like Velázquez, Victoria was employed by the monarch – in Victoria's case, in the service of the queen. The Requiem he wrote upon her death in 1603 is regarded as one of his most enduring and complex works.

Francisco Guerrero

Francisco Guerrero, a Spanish composer of the 16th century. He was second only to Victoria as a major Spanish composer of church music in the second half of the 16th century. Of all the Spanish Renaissance composers, he was the one who lived and worked the most in Spain. Others, e.g. Morales and Victoria, spent large portions of their careers in Italy. Guerrero's music was both religious and secular, unlike that of Victoria and Morales, the two other Spanish 16th-century composers of the first rank. He wrote numerous secular songs and instrumental pieces, in addition to masses, motets, and Passions. He was able to capture an astonishing variety of moods in his music, from elation to despair, longing, depression, and devotion; his music remained popular for hundreds of years, especially in cathedrals in Latin America. Stylistically he preferred homophonic textures, rather like his Spanish contemporaries, and he wrote memorable, singable lines. One interesting feature of his style is how he anticipated functional harmonic usage: there is a case of a Magnificat discovered in Lima, Peru, once thought to be an anonymous 18th century work, which turned out to be a work of his.

Alonso Lobo

Victoria's work was complemented by Alonso Lobo – a man Victoria respected as his equal. Lobo's work – also choral and religious in its content – stressed the austere, minimalist nature of religious music. Lobo sought out a medium between the emotional intensity of Victoria and the technical ability of Palestrina; the solution he found became the foundation of the Baroque musical style in Spain.

Cristóbal de Morales

Regarded as one of the finest composers in Europe around the middle of the 16th century, Cristóbal de Morales was born in Seville in 1500 and employed in Rome from 1535 until 1545 by the Vatican. Almost all of his music is religious, and all of it is vocal, though instruments may have been used in an accompanying role in performance. Morales also wrote two masses on the famous L'homme armé tune, which was often set by composers in the late 15th and 16th centuries. One of these masses is for four voices, and the other for five. The four voice mass uses the tune as a strict cantus firmus, and the setting for five voices treats it more freely, migrating it from one voice to another.

Other significant musicians

Literature

Cervantes' Don Quixote (1605), original title page

The Spanish Golden Age was a time of great flourishing in poetry, prose and drama.

Cervantes and Don Quixote

Regarded by many as one of the finest works in any language, El ingenioso hidalgo Don Quixote de la Mancha by Miguel de Cervantes was the first novel published in Europe; it gave Cervantes a stature in the Spanish-speaking world comparable to his contemporary William Shakespeare in English. The novel, like Spain itself, was caught between the Middle Ages and the modern world. A veteran of the Battle of Lepanto (1571), Cervantes had fallen on hard times in the late 1590s and was imprisoned for debt in 1597, and some believe that during these years he began work on his best-remembered novel. The first part of the novel was published in 1605; the second in 1615, a year before the author's death. Don Quixote resembled both the medieval, chivalric romances of an earlier time and the novels of the early modern world. It parodied classical morality and chivalry, found comedy in knighthood, and criticized social structures and the perceived madness of Spain's rigid society. The work has endured to the present day as a landmark in world literary history, and it was an immediate international hit in its own time, interpreted variously as a satirical comedy, social commentary and forbearer of self-referential literature.

Lope de Vega and Spanish drama

Title page of a comedy by Spanish playwright Lope de Vega

A contemporary of Cervantes, Lope de Vega consolidated the essential genres and structures which would characterize the Spanish commercial drama, also known as the "Comedia", throughout the 17th century. While Lope de Vega wrote prose and poetry as well, he is best remembered for his plays, particularly those grounded in Spanish history. Like Cervantes, Lope de Vega served with the Spanish army and was fascinated with the Spanish nobility. In the hundreds of plays he wrote, with settings ranging from the Biblical times to legendary Spanish history to classical mythology to his own time, Lope de Vega frequently took a comical approach just as Cervantes did, taking a conventional moral play and dressing it up in good humor and cynicism. His stated goal was to entertain the public, much as Cervantes's was. In bringing morality, comedy, drama, and popular wit together, Lope de Vega is often compared to his English contemporary Shakespeare. Some have argued that as a social critic, Lope de Vega attacked, like Cervantes, many of the ancient institutions of his country – aristocracy, chivalry, and rigid morality, among others. Lope de Vega and Cervantes represented an alternative artistic perspective to the religious asceticism of Francisco Zurbarán. Lope de Vega's "cloak-and-sword" plays, which mingled intrigue, romance, and comedy together were carried on by his literary successor, Pedro Calderón de la Barca, in the later seventeenth century.

Poetry

This period also produced some of the most important Spanish works of poetry. The introduction and influence of Italian Renaissance verse is apparent perhaps most vividly in the works of Garcilaso de la Vega and illustrate a profound influence on later poets. Mystical literature in Spanish reached its summit with the works of San Juan de la Cruz and Teresa of Ávila. Baroque poetry was dominated by the contrasting styles of Francisco de Quevedo and Luis de Góngora; both had a lasting influence on subsequent writers, and even on the Spanish language itself. Lope de Vega was a gifted poet of his own, and there were a vast quantity of remarkable poets at that time, though less known: Francisco de Rioja, Bartolomé Leonardo de Argensola, Lupercio Leonardo de Argensola, Bernardino de Rebolledo, Rodrigo Caro, and Andrés Rey de Artieda. Another poet was Sor Juana Inés de la Cruz, from the Spanish colonies overseas, the New Spain ( modern day Mexico).

The picaresque genre flourished in this era, describing the life of pícaros, living by their wits in a decadent society. Distinguished examples are El buscón, by Francisco de Quevedo, Guzmán de Alfarache by Mateo Alemán, Estebanillo González and the anonymously published Lazarillo de Tormes (1554), which created the genre.

Other significant authors

Other well-known playwrights of the period include:

Rhetoric

As elsewhere in Europe, Spanish scholars participated in the humanist recovery and theorizing of Greek and Roman rhetorics. Early Spanish humanists include Antonio Nebrija and Juan Luis Vives. Spanish rhetoricians who discussed Ciceronianism include Juan Lorenzo Palmireno and Pedro Juan Núñez. Famous Spanish Ramists include Francisco Sánchez de Brozas, Pedro Juan Núñez, Fadrique Furió Ceriol, and Luis de Verga. Many other rhetoricians turned to Greek rhetorics from Hermogenes and Longinus which were preserved by Byzantine scholars, especially George of Trebizond. These Byzantine-inspired Spanish rhetoricians include Antonio Lull, Pedro Juan Núñez, and Luis de Granada. There were also many translators of progymnasmata, including Francisco de Vergara, Francisco Escobar, Juan de Mal Lara, Juan Pérez, Antionio Lull, Juan Lorenzo Palmireno, and Pedro Juan Núñez. Another important Spanish rhetorician is Cypriano Soarez, whose rhetorical handbook was a key textbook in the Jesuit Ratio studiorum which was used in Jesuit education throughout the Spanish empire. Diego de Válades´s Rhetorica christiana is the first Western rhetoric published by a native of México. Besides Soarez´s De arte rhetorica, the progymnasmata by Pedro Juan Núñez was also published in Mexico City. Examples of Nahua oratory (huehuetlatolli) were collected by Andrés de Olmos and Bernardino de Sahagún.

Triboluminescence

From Wikipedia, the free encyclopedia
 
Triboluminescence of nicotine L-salicylate

Triboluminescence is a phenomenon in which light is generated when a material is mechanically pulled apart, ripped, scratched, crushed, or rubbed (see tribology). The phenomenon is not fully understood, but appears to be caused by the separation and reunification of static electrical charges. The term comes from the Greek τρίβειν ("to rub"; see tribology) and the Latin lumen (light). Triboluminescence can be observed when breaking sugar crystals and peeling adhesive tapes.

Triboluminescence is often used as a synonym for fractoluminescence (a term sometimes used when referring only to light emitted from fractured crystals). Triboluminescence differs from piezoluminescence in that a piezoluminescent material emits light when it is deformed, as opposed to broken. These are examples of mechanoluminescence, which is luminescence resulting from any mechanical action on a solid.

History

An Uncompahgre Ute Buffalo rawhide ceremonial rattle filled with quartz crystals. Flashes of light are visible when the quartz crystals are subjected to mechanical stress in darkness.

Uncompahgre Ute indigenous people

The Uncompahgre Ute indigenous people from Central Colorado are one of the first documented groups of people in the world credited with the application of mechanoluminescence involving the use of quartz crystals to generate light. The Ute constructed special ceremonial rattles made from buffalo rawhide which they filled with clear quartz crystals collected from the mountains of Colorado and Utah. When the rattles were shaken at night during ceremonies, the friction and mechanical stress of the quartz crystals impacting together produced flashes of light visible through the translucent buffalo hide.

First scientific reports

The first recorded observation is attributed to English scholar Francis Bacon when he recorded in his 1620 Novum Organum that "It is well known that all sugar, whether candied or plain, if it be hard, will sparkle when broken or scraped in the dark." The scientist Robert Boyle also reported on some of his work on triboluminescence in 1663. In the late 1790s, sugar production began to produce more refined sugar crystals. These crystals were formed into a large solid cone for transport and sale. This solid cone of sugar had to be broken into usable chunks using a device known as sugar nips. People began to notice that as sugar was "nipped" in low light, tiny bursts of light were visible.

A historically important instance of triboluminescence occurred in Paris in 1675. Astronomer Jean-Felix Picard observed that his barometer was glowing in the dark as he carried it. His barometer consisted of a glass tube that was partially filled with mercury. Whenever the mercury slid down the glass tube, the empty space above the mercury would glow. While investigating this phenomenon, researchers discovered that static electricity could cause low-pressure air to glow. This discovery revealed the possibility of electric lighting.

Mechanism of action

Materials scientists have not yet arrived at a full understanding of the effect, but the current theory of triboluminescence — based upon crystallographic, spectroscopic, and other experimental evidence — is that upon fracture of asymmetrical materials, charge is separated. When the charges recombine, the electrical discharge ionizes the surrounding air, causing a flash of light. Research further suggests that crystals which display triboluminescence must lack symmetry (thus being anisotropic in order to permit charge separation) and be poor conductors. However, there are substances which break this rule, and which do not possess asymmetry, yet display triboluminescence anyway, such as hexakis(antipyrine)terbium iodide. It is thought that these materials contain impurities, which make the substance locally asymmetric.

The biological phenomenon of triboluminescence is conditioned by recombination of free radicals during mechanical activation.

Examples

In common materials

Certain household materials and substances can be seen to exhibit the property:

  • Ordinary pressure-sensitive tape ("Scotch tape") displays a glowing line where the end of the tape is being pulled away from the roll. Soviet scientists observed in 1953 that unpeeling a roll of tape in a vacuum produced X-rays. The mechanism of X-ray generation was studied further in 2008. Similar X-ray emissions have also been observed with metals.
  • Opening an envelope sealed with polymer glue generates light that can be viewed as blue flashes in darkness.
  • When sugar crystals are crushed, tiny electrical fields are created, separating positive and negative charges that then create sparks while trying to reunite. Wint-O-Green Life Savers work especially well for creating such sparks, because wintergreen oil (methyl salicylate) is fluorescent and converts ultraviolet light into blue light.

A diamond may begin to glow while being rubbed; this occasionally happens to diamonds while a facet is being ground or the diamond is being sawn during the cutting process. Diamonds may fluoresce blue or red. Some other minerals, such as quartz, are triboluminescent, emitting light when rubbed together.

Triboluminescence can occur when a Prince Rupert's Drop is shattered by a powerful force, such as a bullet. A bright flash of white light may proceed ahead of the cracking down from the head of the drop towards the tail.

Triboluminescence is a biological phenomenon observed in mechanical deformation and Contact electrification of epidermal surface of osseous and soft tissues, at chewing food, at friction in joints of vertebrae, during sexual intercourse, and during blood circulation.

Water jet abrasive cutting of ceramics (e.g. tiles) creates a yellow/orange glow at the point of impact of very high speed flow.

Chemicals notable for their triboluminescence

  • Europium tetrakis (dibenzoylmethide)triethylammonium emits particularly bright red flashes upon the destruction of its crystals.
  • Triphenylphosphinebis(pyridine)thiocyanatocopper(I) emits a reasonably strong blue light when crystals of it are fractured. This luminescence is not as extreme as the red luminescence, however is still very clearly visible to the naked eye in standard settings.
  • N-Acetylanthranilic acid emits a deep blue light when its crystals are fractured.

Fractoluminescence

Fractoluminescence is often used as a synonym for triboluminescence. It is the emission of light from the fracture (rather than rubbing) of a crystal, but fracturing often occurs with rubbing. Depending upon the atomic and molecular composition of the crystal, when the crystal fractures a charge separation can occur making one side of the fractured crystal positively charged and the other side negatively charged. Like in triboluminescence, if the charge separation results in a large enough electric potential, a discharge across the gap and through the bath gas between the interfaces can occur. The potential at which this occurs depends upon the dielectric properties of the bath gas.

EMR propagation during fracturing

The emission of electromagnetic radiation (EMR) during plastic deformation and crack propagation in metals and rocks has been studied. The EMR emissions from metals and alloys have also been explored and confirmed. Molotskii presented a dislocation mechanism for this type of EMR emission. Recently, Srilakshmi and Misra reported an additional phenomenon of secondary EMR during plastic deformation and crack propagation in uncoated and metal-coated metals and alloys.

Theory

EMR during the micro-plastic deformation and crack propagation from several metals and alloys and transient magnetic field generation during necking in ferromagnetic metals were reported by Misra (1973–75), which have been confirmed and explored by several researchers. Tudik and Valuev (1980) were able to measure the EMR frequency during tensile fracture of iron and aluminum in the region 10^14 Hz by using photomultipliers. Srilakshmi and Misra (2005a) also reported an additional phenomenon of secondary electromagnetic radiation in uncoated and metal-coated metals and alloys. If a solid material is subjected to stresses of large amplitudes, which can cause plastic deformation and fracture, emissions such as thermal, acoustic, ions, exo-emissions occur. With the discovery of new materials and advancement in instrumentation to measure effects of EMR, crack formation and fracture; the EMR emissions effect becomes important.

Generation of X-Rays

In a moderate vacuum, peeling tape generated x-rays sufficient to x-ray a human finger.

Deformation induced EMR

The study of deformation is essential for the development of new materials. Deformation in metals depends on temperature, type of stress applied, strain rate, oxidation and corrosion. Deformation induced EMR can be divided into three categories: effects in ionic crystal materials; effects in rocks and granites; and, effects in metals and alloys. EMR emission depends on the orientation of the grains in individual crystals since material properties are different in differing directions. Amplitude of EMR pulse increases as long as the crack continues to grow as new atomic bonds are broken and it leads to EMR. The Pulse starts to decay as cracking halts. Observations from experiments showed that emitted EMR signals contain mixed frequency components.

Test methods to measure EMR

Most widely tensile test method is used to characterize the mechanical properties of materials. From any complete tensile test record, one can obtain important information about the material's elastic properties, the character and extent of plastic deformation, yield and tensile strengths and toughness. The information which can be obtained from one test justifies the extensive use of tensile test in engineering materials research. Therefore, investigations of EMR emissions are mainly based on the tensile test of the specimens. From experiments, it can be shown that tensile crack formation excites more intensive EMR than shear cracking, increasing the elasticity, strength and loading rate during uniaxial loading increases amplitude. Poisson's ratio is a key parameter for EMR characterization during triaxial compression. If the Poisson's ratio is lower, it is harder for the material to strain transversally and hence higher is the probability of new fractures. Mechanism of plastic deformation is very important for safe operation of any component under dynamic conditions.

Uses and applications

This EMR can be utilized in developing sensors/smart materials. This technique can be implemented in powder metallurgy technique also. EMR is one of these emissions which accompany large deformation. If an element can be identified which gives maximum EMR response with minimum mechanical stimulus then it can be incorporated into main material and thus set new trends in the development of smart material. The deformation induced EMR can serve as a strong tool for failure detection and prevention.

Orel V.E. invented the device to measure EMR whole blood and lymphocytes in laboratory diagnostics.

Metric prefix

From Wikipedia, the free encyclopedia

A metric prefix is a unit prefix that precedes a basic unit of measure to indicate a multiple or submultiple of the unit. All metric prefixes used today are decadic. Each prefix has a unique symbol that is prepended to any unit symbol. The prefix kilo-, for example, may be added to gram to indicate multiplication by one thousand: one kilogram is equal to one thousand grams. The prefix milli-, likewise, may be added to metre to indicate division by one thousand; one millimetre is equal to one thousandth of a metre.

A metric power is an integer unit affix, written in superscript in formal typography, that follows the basic unit of measure to indicate a multiplicity of the basic unit. In electronic plain text where superscript is not available, the subscript is often omitted, or where confusion is possible, indicated by placing the caret symbol ^ between the base unit and the integer power, thus km2, km2, and km^2 are variously encountered. When no integer affix is supplied, the implied power is 1. When a unit is not mentioned at all, the implied power is 0. Negative powers imply division. With extreme formality, the unit m/s2 can also be rendered m1s-2, but the literal present of the implied integer 1 is considered unconventional in common usage. Often all the units with positive prefixes will be listed first (in some natural order), followed by all the units with negative prefixes (in some natural order); this semi-canonical form is most easily mapped by the mind onto division notation, and makes switching between the two conventions less mentally onerous.

Decimal multiplicative prefixes have been a feature of all forms of the metric system, with six of these dating back to the system's introduction in the 1790s. Metric prefixes have also been used with some non-metric units. The SI prefixes are metric prefixes that were standardized for use in the International System of Units (SI) by the International Bureau of Weights and Measures (BIPM) in resolutions dating from 1960 to 1991. Since 2009, they have formed part of the International System of Quantities. They are also used in the Unified Code for Units of Measure (UCUM)

List of SI prefixes

The BIPM specifies twenty prefixes for the International System of Units (SI).

Prefix Base 10 Decimal English word Adoption
Name Symbol Short scale Long scale
yotta Y 1024 1000000000000000000000000 septillion quadrillion 1991
zetta Z 1021 1000000000000000000000 sextillion trilliard 1991
exa E 1018 1000000000000000000 quintillion trillion 1975
peta P 1015 1000000000000000 quadrillion billiard 1975
tera T 1012 1000000000000 trillion billion 1960
giga G 109 1000000000 billion milliard 1960
mega M 106 1000000 million 1873
kilo k 103 1000 thousand 1795
hecto h 102 100 hundred 1795
deca da 101 10 ten 1795

100 1 one
deci d 10−1 0.1 tenth 1795
centi c 10−2 0.01 hundredth 1795
milli m 10−3 0.001 thousandth 1795
micro μ 10−6 0.000001 millionth 1873
nano n 10−9 0.000000001 billionth milliardth 1960
pico p 10−12 0.000000000001 trillionth billionth 1960
femto f 10−15 0.000000000000001 quadrillionth billiardth 1964
atto a 10−18 0.000000000000000001 quintillionth trillionth 1964
zepto z 10−21 0.000000000000000000001 sextillionth trilliardth 1991
yocto y 10−24 0.000000000000000000000001 septillionth quadrillionth 1991
  1. Prefixes adopted before 1960 already existed before SI. The introduction of the CGS system was in 1873.

Each prefix name has a symbol that is used in combination with the symbols for units of measure. For example, the symbol for kilo- is k, and is used to produce km, kg, and kW, which are the SI symbols for kilometre, kilogram, and kilowatt, respectively. Except for the early prefixes of kilo-, hecto-, and deca-, the symbols for the multiplicative prefixes are uppercase letters, and those for the fractional prefixes are lowercase letters. There is a Unicode symbol for micro µ for use when the Greek letter μ is unavailable. When both are unavailable, the visually similar lowercase Latin letter u is commonly used instead. SI unit symbols are never italicised.

Prefixes corresponding to an integer power of one thousand are generally preferred. Hence 100 m is preferred over 1 hm (hectometre) or 10 dam (decametres). The prefixes deci-, and centi-, and less frequently hecto- and deca-, are commonly used for everyday purposes, and the centimetre (cm) is especially common. Some modern building codes require that the millimetre be used in preference to the centimetre, because "use of centimetres leads to extensive usage of decimal points and confusion".

Prefixes may not be used in combination. This also applies to mass, for which the SI base unit (kilogram) already contains a prefix. For example, milligram (mg) is used instead of microkilogram (μkg).

In the arithmetic of measurements having units, the units are treated as multiplicative factors to values. If they have prefixes, all but one of the prefixes must be expanded to their numeric multiplier, except when combining values with identical units. Hence:

  • 5 mV × 5 mA = 5×10−3 V × 5×10−3 A = 25×10−6 V⋅A = 25 μW.
  • 5.00 mV + 10 μV = 5.00 mV + 0.01 mV = 5.01 mV.

Metric powers

When powers of units occur, for example, squared or cubed, the multiplicative prefix must be considered part of the unit, and thus included in the exponentiation:

Examples with prefixes and powers

  • 5 cm5×10−2 m5 × 0.01 m = 0.05 m.
  • 9 km29 × (103 m)29 × (103)2 × m29×106 m29 × 1000000 m29000000 m2.
  • 3 MW = 3×106 W = 3 × 1000000 W = 3000000 W.

Application to units of measurement

The use of prefixes can be traced back to the introduction of the metric system in the 1790s, long before the 1960 introduction of the SI. The prefixes, including those introduced after 1960, are used with any metric unit, whether officially included in the SI or not (e.g., millidynes and milligauss). Metric prefixes may also be used with non-metric units.

The choice of prefixes with a given unit is usually dictated by convenience of use. Unit prefixes for amounts that are much larger or smaller than those actually encountered are seldom used.

Metric units

Mass

The units kilogram, gram, milligram, microgram, and smaller are commonly used for measurement of mass. However, megagram, gigagram, and larger are rarely used; tonnes (and kilotonnes, megatonnes, etc.) or scientific notation are used instead. Megagram and teragram are occasionally used to disambiguate the tonne from other units with the name "ton".

The kilogram is the only base unit of the International System of Units that includes a metric prefix.

Volume

The litre (equal to a cubic decimetre), millilitre (equal to a cubic centimetre), microlitre, and smaller are common. In Europe, the centilitre is often used for liquids, and the decilitre is used less frequently. Bulk agricultural products, such as grain, beer and wine, are often measured in hectolitres (each 100 litres in size).

Larger volumes are usually denoted in kilolitres, megalitres or gigalitres, or else in cubic metres (1 cubic metre = 1 kilolitre) or cubic kilometres (1 cubic kilometre = 1 teralitre). For scientific purposes, the cubic metre is usually used.

Length

The kilometre, metre, centimetre, millimetre, and smaller units are common. The decimetre is rarely used. The micrometre is often referred to by the older non-SI name micron. In some fields, such as chemistry, the ångström (0.1 nm) has been used commonly instead of the nanometre. The femtometre, used mainly in particle physics, is sometimes called a fermi. For large scales, megametre, gigametre, and larger are rarely used. Instead, ad hoc non-metric units are used, such as the solar radius, astronomical units, light years, and parsecs; the astronomical unit is mentioned in the SI standards as an accepted non-SI unit.

Time

Prefixes for the SI standard unit second are most commonly encountered for quantities less than one second. For larger quantities, the system of minutes (60 seconds), hours (60 minutes) and days (24 hours) is accepted for use with the SI and more commonly used. When speaking of spans of time, the length of the day is usually standardized to 86400 seconds so as not to create issues with the irregular leap second.

Larger multiples of the second such as kiloseconds and megaseconds are occasionally encountered in scientific contexts, but are seldom used in common parlance. For long-scale scientific work, particularly in astronomy, the Julian year or annum is a standardized variant of the year, equal to exactly 31557600 SI seconds (365 days, 6 hours). The unit is so named because it was the average length of a year in the Julian calendar. Long time periods are then expressed by using metric prefixes with the annum, such as megaannum or gigaannum.

Angle

The SI unit of angle is the radian, but degrees, as well as arc-minutes and arc-seconds, see some scientific use.

Temperature

Official policy also varies from common practice for the degree Celsius (°C). NIST states: "Prefix symbols may be used with the unit symbol °C and prefix names may be used with the unit name degree Celsius. For example, 12 m°C (12 millidegrees Celsius) is acceptable." In practice, it is more common for prefixes to be used with the kelvin when it is desirable to denote extremely large or small absolute temperatures or temperature differences. Thus, temperatures of star interiors may be given in units of MK (megakelvins), and molecular cooling may be described in mK (millikelvins).

Energy

In use the joule and kilojoule are common, with larger multiples seen in limited contexts. In addition, the kilowatt-hour, a composite unit formed from the kilowatt and hour, is often used for electrical energy; other multiples can be formed by modifying the prefix of watt (e.g. terawatt-hour).

There exist a number of definitions for the non-SI unit, the calorie. There are gram calories and kilogram calories. One kilogram calorie, which equals one thousand gram calories, often appears capitalized and without a prefix (i.e. Cal) when referring to "dietary calories" in food. It is common to apply metric prefixes to the gram calorie, but not to the kilogram calorie: thus, 1 kcal = 1000 cal = 1 Cal.

Non-metric units

Metric prefixes are widely used outside the metric SI system. Common examples include the megabyte and the decibel. Metric prefixes rarely appear with imperial or US units except in some special cases (e.g., microinch, kilofoot, kilopound). They are also used with other specialized units used in particular fields (e.g., megaelectronvolt, gigaparsec, millibarn). They are also occasionally used with currency units (e.g., gigadollar), mainly by people who are familiar with the prefixes from scientific usage. In astronomy, geology, and paleontology, the year, with symbol a (from the Latin annus), is commonly used with metric prefixes: ka, Ma, and Ga.

Official policies about the use of SI prefixes with non-SI units vary slightly between the International Bureau of Weights and Measures (BIPM) and the American National Institute of Standards and Technology (NIST). For instance, the NIST advises that 'to avoid confusion, prefix symbols (and prefix names) are not used with the time-related unit symbols (names) min (minute), h (hour), d (day); nor with the angle-related symbols (names) ° (degree), ′ (minute), and ″ (second), whereas the BIPM adds information about the use of prefixes with the symbol as for arcsecond when they state: "However astronomers use milliarcsecond, which they denote mas, and microarcsecond, μas, which they use as units for measuring very small angles."

An advantage of the SI system decimal prefixes is that they make for simplicity of calculation and conversion involving units of different sizes; consider for example the simplicity of buying 13 items of 390 g weight at €12.34 per kilogram, compared with items of 13+34 oz at $4.79 per pound (or, worse, with old non-decimalized currency: £4/15/9+12). In the units used in the US, combining of units that are not decimal multiples of each other is often avoided by not mixing the units used, e.g., using inches, feet or miles only: 89  inches rather than 7 feet 5 inches (or 2 yards, 1 foot 5 inches).

Presentation

Pronunciation

When a metric prefix is affixed to a root word, the prefix carries the stress, while the root drops its stress but retains a full vowel in the syllable that is stressed when the root word stands alone. For example, kilobyte is /ˈkɪlɒbt/, with stress on the first syllable. However, units in common use outside the scientific community may be stressed idiosyncratically. In English-speaking countries, kilometre is the most conspicuous example. It is often pronounced /kɪˈlɒmɪtər/, with reduced vowels on both syllables of metre. This stress is not applied to other multiples or sub-multiples of metre, or to other units prefixed with kilo-.

The prefix giga is usually pronounced in English as /ˈɡɪɡə/, with hard ⟨g⟩ as in get, but sometimes /ˈɪɡə/, with soft ⟨g⟩ as in gin.

Typesetting

The LaTeX typesetting system features an SIunitx package in which the units of measurement are spelled out, for example, \SI{3}{\tera\hertz} formats as "3 THz".

Non-standard prefixes

Distance marker on the Rhine: 36 (XXXVI) myriametres from Basel. The stated distance is 360 km; the decimal mark in Germany is a comma.

Obsolete metric prefixes

Some of the prefixes formerly used in the metric system have fallen into disuse and were not adopted into the SI. The decimal prefix for ten thousand, myria- (sometimes spelled myrio-), and the prefixes double- (2×) and demi- (1/2×) were parts of the original metric system adopted by France in 1795, but were not retained when the SI prefixes were internationally adopted by the 11th CGPM conference in 1960.

Other metric prefixes used historically include hebdo- (107) and micri- (10−14).

Double prefixes

Double prefixes have been used in the past, such as micromillimetres or millimicrons (now nanometres), micromicrofarads (μμF; now picofarads, pF), kilomegatons (now gigatons), hectokilometres (now 100 kilometres) and the derived adjective hectokilometric (typically used for qualifying the fuel consumption measures). These are not compatible with the SI.

Other obsolete double prefixes included "decimilli-" (10−4), which was contracted to "dimi-" and standardized in France up to 1961.

Proposed prefixes

A proposal made in 2019 to the BIPM is ronna (R) for 1027, quecca (Q) for 1030, ronto (r) for 10−27 and quecto (q) for 10−30. A 2022 draft resolution by the BIPM revises this with quetta in place of quecca.

Similar symbols and abbreviations

In written English, the symbol K is often used informally to indicate a multiple of thousand in many contexts. For example, one may talk of a 40K salary (40000), or call the Year 2000 problem the Y2K problem. In these cases, an uppercase K is often used with an implied unit (although it could then be confused with the symbol for the kelvin temperature unit if the context is unclear). This informal postfix is read or spoken as "thousand" or "grand", or just "k".

The financial and general news media mostly use m or M, b or B, and t or T as abbreviations for million, billion (109) and trillion (1012), respectively, for large quantities, typically currency and population.

The medical and automotive fields in the United States use the abbreviations cc or ccm for cubic centimetres. One cubic centimetre is equal to one millilitre.

For nearly a century, engineers used the abbreviation MCM to designate a "thousand circular mils" in specifying the cross-sectional area of large electrical cables. Since the mid-1990s, kcmil has been adopted as the official designation of a thousand circular mils, but the designation MCM still remains in wide use. A similar system is used in natural gas sales in the United States: m (or M) for thousands and mm (or MM) for millions of British thermal units or therms, and in the oil industry, where MMbbl is the symbol for "millions of barrels". This usage of the capital letter M for "thousand" is from Roman numerals, in which M means 1000.

Binary prefixes

In some fields of information technology, it has been common to designate non-decimal multiples based on powers of 1024, rather than 1000, for some SI prefixes (kilo-, mega-, giga-), contrary to the definitions in the International System of Units (SI). This practice was once sanctioned by some industry associations, including JEDEC. The International Electrotechnical Commission (IEC) standardized the system of binary prefixes (kibi-, mebi-, gibi-, etc.) for this purpose.

Introduction to entropy

From Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Introduct...