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Wednesday, February 25, 2015

Leonardo da Vinci



From Wikipedia, the free encyclopedia

Leonardo da Vinci
Francesco Melzi - Portrait of Leonardo - WGA14795.jpg
Portrait of Leonardo by Francesco Melzi
Born Leonardo di ser Piero da Vinci
(1452-04-15)April 15, 1452
Vinci, Republic of Florence (present-day Italy)
Died May 2, 1519(1519-05-02) (aged 67)
Amboise, Kingdom of France
Known for Diverse fields of the arts and sciences
Notable work(s) Mona Lisa
The Last Supper
The Vitruvian Man
Lady with an Ermine
Style High Renaissance
Signature Firma de Leonardo Da Vinci.svg

Leonardo di ser Piero da Vinci (Italian: [leoˈnardo da ˈvintʃi]; 15 April 1452 – 2 May 1519) was an Italian polymath, painter, sculptor, architect, musician, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist, and writer. He is widely considered to be one of the greatest painters of all time and perhaps the most diversely talented person ever to have lived.[1] His genius, perhaps more than that of any other figure, epitomized the Renaissance humanist ideal. Leonardo has often been described as the archetype of the Renaissance Man, a man of "unquenchable curiosity" and "feverishly inventive imagination".[2] According to art historian Helen Gardner, the scope and depth of his interests were without precedent and "his mind and personality seem to us superhuman, the man himself mysterious and remote".[2] Marco Rosci states that while there is much speculation about Leonardo, his vision of the world is essentially logical rather than mysterious, and that the empirical methods he employed were unusual for his time.[3]

Born out of wedlock to a notary, Piero da Vinci, and a peasant woman, Caterina, in Vinci in the region of Florence, Leonardo was educated in the studio of the renowned Florentine painter Verrocchio. Much of his earlier working life was spent in the service of Ludovico il Moro in Milan. He later worked in Rome, Bologna and Venice, and he spent his last years in France at the home awarded him by Francis I.

Leonardo was, and is, renowned primarily as a painter. Among his works, the Mona Lisa is the most famous and most parodied portrait[4] and The Last Supper the most reproduced religious painting of all time, with their fame approached only by Michelangelo's The Creation of Adam.[2] Leonardo's drawing of the Vitruvian Man is also regarded as a cultural icon,[5] being reproduced on items as varied as the euro coin, textbooks, and T-shirts. Perhaps fifteen of his paintings have survived, the small number because of his constant, and frequently disastrous, experimentation with new techniques, and his chronic procrastination.[citation needed][nb 1] Nevertheless, these few works, together with his notebooks, which contain drawings, scientific diagrams, and his thoughts on the nature of painting, compose a contribution to later generations of artists rivalled only by that of his contemporary, Michelangelo.

Leonardo is revered for his technological ingenuity. He conceptualised flying machines, an armoured vehicle, concentrated solar power, an adding machine,[6] and the double hull, also outlining a rudimentary theory of plate tectonics. Relatively few of his designs were constructed or were even feasible during his lifetime,[nb 2] but some of his smaller inventions, such as an automated bobbin winder and a machine for testing the tensile strength of wire, entered the world of manufacturing unheralded.[nb 3] He made important discoveries in anatomy, civil engineering, optics, and hydrodynamics, but he did not publish his findings and they had no direct influence on later science.[7]

Life

Childhood, 1452–1466

Photo of a building of rough stone with small windows, surrounded by olive trees
Leonardo's childhood home in Anchiano
 Pen drawing of a landscape with mountains, a river in a deep valley, and a small castle
Leonardo's earliest known drawing, the Arno Valley (1473), Uffizi

Leonardo was born on 15 April 1452 (Old Style), "at the third hour of the night"[nb 4] in the Tuscan hill town of Vinci, in the lower valley of the Arno River in the territory of the Medici-ruled Republic of Florence.[9] He was the out-of-wedlock son of the wealthy Messer Piero Fruosino di Antonio da Vinci, a Florentine legal notary, and Caterina, a peasant.[8][10][nb 5] Leonardo had no surname in the modern sense, "da Vinci" simply meaning "of Vinci": his full birth name was "Lionardo di ser Piero da Vinci", meaning "Leonardo, (son) of (Mes)ser Piero from Vinci".[9] The inclusion of the title "ser" indicated that Leonardo's father was a gentleman.

Little is known about Leonardo's early life. He spent his first five years in the hamlet of Anchiano in the home of his mother, then from 1457 he lived in the household of his father, grandparents and uncle, Francesco, in the small town of Vinci. His father had married a sixteen-year-old girl named Albiera, who loved Leonardo but died young.[11] When Leonardo was sixteen his father married again, to twenty-year-old Francesca Lanfredini. It was not until his third and fourth marriages that Ser Piero produced legitimate heirs.[12]

Leonardo received an informal education in Latin, geometry and mathematics. In later life, Leonardo recorded only two childhood incidents. One, which he regarded as an omen, was when a kite dropped from the sky and hovered over his cradle, its tail feathers brushing his face.[13] The second occurred while he was exploring in the mountains: he discovered a cave and was both terrified that some great monster might lurk there and driven by curiosity to find out what was inside.[11]

Leonardo's early life has been the subject of historical conjecture.[14] Vasari, the 16th-century biographer of Renaissance painters, tells of how a local peasant made himself a round shield and requested that Ser Piero have it painted for him. Leonardo responded with a painting of a monster spitting fire which was so terrifying that Ser Piero sold it to a Florentine art dealer, who sold it to the Duke of Milan. Meanwhile, having made a profit, Ser Piero bought a shield decorated with a heart pierced by an arrow, which he gave to the peasant.[15]
Painting showing Jesus, naked except for a loin-cloth, standing in a shallow stream in a rocky landscape, while to the right, John the Baptist, identifiable by the cross that he carries, tips water over Jesus' head. Two angels kneel at the left. Above Jesus are the hands of God, and a dove descending
The Baptism of Christ (1472–1475)—Uffizi, by Verrocchio and Leonardo

Verrocchio's workshop, 1466–1476

In 1466, at the age of fourteen, Leonardo was apprenticed to the artist Andrea di Cione, known as Verrocchio, whose workshop was "one of the finest in Florence".[16] Other famous painters apprenticed or associated with the workshop include Domenico Ghirlandaio, Perugino, Botticelli, and Lorenzo di Credi.[11][17] Leonardo would have been exposed to both theoretical training and a vast range of technical skills[18] including drafting, chemistry, metallurgy, metal working, plaster casting, leather working, mechanics and carpentry as well as the artistic skills of drawing, painting, sculpting and modelling.[19][nb 6]

Much of the painted production of Verrocchio's workshop was done by his employees. According to Vasari, Leonardo collaborated with Verrocchio on his The Baptism of Christ, painting the young angel holding Jesus' robe in a manner that was so far superior to his master's that Verrocchio put down his brush and never painted again.[20] On close examination, the painting reveals much that has been painted or touched-up over the tempera using the new technique of oil paint, with the landscape, the rocks that can be seen through the brown mountain stream and much of the figure of Jesus bearing witness to the hand of Leonardo.[21] Leonardo may have been the model for two works by Verrocchio: the bronze statue of David in the Bargello and the Archangel Raphael in Tobias and the Angel.[10]

By 1472, at the age of twenty, Leonardo qualified as a master in the Guild of St Luke, the guild of artists and doctors of medicine,[nb 7] but even after his father set him up in his own workshop, his attachment to Verrocchio was such that he continued to collaborate with him.[11] Leonardo's earliest known dated work is a drawing in pen and ink of the Arno valley, drawn on August 5, 1473.[nb 8][17]

Professional life, 1476–1513


Florentine court records of 1476 show that Leonardo and three other young men were charged with sodomy but acquitted.[10][nb 9] From that date until 1478 there is no record of his work or even of his whereabouts.[22] In 1478 he left Verrocchio's studio and was no longer resident at his father's house. One writer, the "Anonimo" Gaddiano claims that in 1480 Leonardo was living with the Medici and working in the Garden of the Piazza San Marco in Florence, a Neo-Platonic academy of artists, poets and philosophers which the Medici had established.[10] In January 1478, he received his first of two independent commissions: to paint an altarpiece for the Chapel of St. Bernard in the Palazzo Vecchio and, in March 1481, The Adoration of the Magi for the monks of San Donato a Scopeto.[23] Neither commission was completed, the second being interrupted when Leonardo went to Milan.

In 1482 Leonardo, who according to Vasari was a most talented musician,[24] created a silver lyre in the shape of a horse's head. Lorenzo de' Medici sent Leonardo to Milan, bearing the lyre as a gift, to secure peace with Ludovico Sforza, Duke of Milan.[25] At this time Leonardo wrote an often-quoted letter describing the many marvellous and diverse things that he could achieve in the field of engineering and informing Ludovico that he could also paint.[17][26]

Leonardo worked in Milan from 1482 until 1499. He was commissioned to paint the Virgin of the Rocks for the Confraternity of the Immaculate Conception and The Last Supper for the monastery of Santa Maria delle Grazie.[27] In the spring of 1485, Leonardo travelled to Hungary on behalf of Ludovico to meet Matthias Corvinus, for whom he is believed to have painted a Holy Family.[28][not in citation given] Between 1493 and 1495 Leonardo listed a woman called Caterina among his dependents in his taxation documents. When she died in 1495, the list of funeral expenditures suggests that she was his mother.[29]

Leonardo was employed on many different projects for Ludovico, including the preparation of floats and pageants for special occasions, designs for a dome for Milan Cathedral and a model for a huge equestrian monument to Francesco Sforza, Ludovico's predecessor. Seventy tons of bronze were set aside for casting it. The monument remained unfinished for several years, which was not unusual for Leonardo. In 1492 the clay model of the horse was completed. It surpassed in size the only two large equestrian statues of the Renaissance, Donatello's Gattamelata in Padua and Verrocchio's Bartolomeo Colleoni in Venice, and became known as the "Gran Cavallo".[17][nb 10] Leonardo began making detailed plans for its casting;[17] however, Michelangelo insulted Leonardo by implying that he was unable to cast it.[11] In November 1494 Ludovico gave the bronze to be used for cannon to defend the city from invasion by Charles VIII.[17]

At the start of the Second Italian War in 1499, the invading French troops used the life-size clay model for the "Gran Cavallo" for target practice. With Ludovico Sforza overthrown, Leonardo, with his assistant Salai and friend, the mathematician Luca Pacioli, fled Milan for Venice[30] where he was employed as a military architect and engineer, devising methods to defend the city from naval attack.[11] On his return to Florence in 1500, he and his household were guests of the Servite monks at the monastery of Santissima Annunziata and were provided with a workshop where, according to Vasari, Leonardo created the cartoon of The Virgin and Child with St. Anne and St. John the Baptist, a work that won such admiration that "men and women, young and old" flocked to see it "as if they were attending a great festival".[31][nb 11]

Leonardo da Vinci's very accurate map of Imola, created for Cesare Borgia

In Cesena, in 1502 Leonardo entered the service of Cesare Borgia, the son of Pope Alexander VI, acting as a military architect and engineer and travelling throughout Italy with his patron.[30] Leonardo created a map of Cesare Borgia's stronghold, a town plan of Imola in order to win his patronage. Maps were extremely rare at the time and it would have seemed like a new concept. Upon seeing it, Cesare hired Leonardo as his chief military engineer and architect. Later in the year, Leonardo produced another map for his patron, one of Chiana Valley, Tuscany, so as to give his patron a better overlay of the land and greater strategic position. He created this map in conjunction with his other project of constructing a dam from the sea to Florence, in order to allow a supply of water to sustain the canal during all seasons.

Leonardo returned to Florence where he rejoined the Guild of St Luke on October 18, 1503, and spent two years designing and painting a mural of The Battle of Anghiari for the Signoria,[30] with Michelangelo designing its companion piece, The Battle of Cascina.[nb 12] In Florence in 1504, he was part of a committee formed to relocate, against the artist's will, Michelangelo's statue of David.[35]

In 1506 Leonardo returned to Milan. Many of his most prominent pupils or followers in painting either knew or worked with him in Milan,[11] including Bernardino Luini, Giovanni Antonio Boltraffio and Marco d'Oggione.[nb 13] However, he did not stay in Milan for long because his father had died in 1504, and in 1507 he was back in Florence trying to sort out problems with his brothers over his father's estate. By 1508 Leonardo was back in Milan, living in his own house in Porta Orientale in the parish of Santa Babila.[36]

Old age, 1513–1519

From September 1513 to 1516, under Pope Leo X, Leonardo spent much of his time living in the Belvedere in the Vatican in Rome, where Raphael and Michelangelo were both active at the time.[36] In October 1515, Francis I of France recaptured Milan.[23] On December 19, Leonardo was present at the meeting of Francis I and Pope Leo X, which took place in Bologna.[11][37][38] Leonardo was commissioned to make for Francis a mechanical lion which could walk forward, then open its chest to reveal a cluster of lilies.[39][nb 14] In 1516, he entered François' service, being given the use of the manor house Clos Lucé[nb 15] near the king's residence at the royal Château d'Amboise. It was here that he spent the last three years of his life, accompanied by his friend and apprentice, Count Francesco Melzi, and supported by a pension totalling 10,000 scudi.[36]
Photo of a large medieval house, built of brick with many windows and gables and a circular tower with a conical roof
Clos Lucé in France, where Leonardo died in 1519

Leonardo died at Clos Lucé, on 2 May 1519. Francis I had become a close friend. Vasari records that the king held Leonardo's head in his arms as he died, although this story, beloved by the French and portrayed in romantic paintings by Ingres, Ménageot and other French artists, as well as by Angelica Kauffman, may be legend rather than fact.[nb 16] Vasari states that in his last days, Leonardo sent for a priest to make his confession and to receive the Holy Sacrament.[41] In accordance with his will, sixty beggars followed his casket.[nb 17] Melzi was the principal heir and executor, receiving as well as money, Leonardo's paintings, tools, library and personal effects. Leonardo also remembered his other long-time pupil and companion, Salai and his servant Battista di Vilussis, who each received half of Leonardo's vineyards, his brothers who received land, and his serving woman who received a black cloak "of good stuff" with a fur edge.[nb 18][42] Leonardo da Vinci was buried in the Chapel of Saint-Hubert in Château d'Amboise, in France.

Some 20 years after Leonardo's death, Francis was reported by the goldsmith and sculptor Benevenuto Cellini as saying: "There had never been another man born in the world who knew as much as Leonardo, not so much about painting, sculpture and architecture, as that he was a very great philosopher."[43]

Relationships and influences


Ghiberti's Gates of Paradise, (1425–1452) were a source of communal pride. Many artists assisted in their creation

Florence: Leonardo's artistic and social background

Florence, at the time of Leonardo's youth, was the centre of Christian Humanist thought and culture.[16] Leonardo commenced his apprenticeship with Verrocchio in 1466, the year that Verrocchio's master, the great sculptor Donatello, died. The painter Uccello, whose early experiments with perspective were to influence the development of landscape painting, was a very old man. The painters Piero della Francesca and Fra Filippo Lippi, sculptor Luca della Robbia, and architect and writer Leon Battista Alberti were in their sixties. The successful artists of the next generation were Leonardo's teacher Verrocchio, Antonio Pollaiuolo and the portrait sculptor, Mino da Fiesole whose lifelike busts give the most reliable likenesses of Lorenzo Medici's father Piero and uncle Giovanni.[44][45][46][47]

Leonardo's youth was spent in a Florence that was ornamented by the works of these artists and by Donatello's contemporaries, Masaccio, whose figurative frescoes were imbued with realism and emotion and Ghiberti whose Gates of Paradise, gleaming with gold leaf, displayed the art of combining complex figure compositions with detailed architectural backgrounds. Piero della Francesca had made a detailed study of perspective,[48] and was the first painter to make a scientific study of light. These studies and Alberti's Treatise[49] were to have a profound effect on younger artists and in particular on Leonardo's own observations and artworks.[44][46][47]

Massaccio's "The Expulsion from the Garden of Eden" depicting the naked and distraught Adam and Eve created a powerfully expressive image of the human form, cast into three dimensions by the use of light and shade, which was to be developed in the works of Leonardo in a way that was to be influential in the course of painting. The humanist influence of Donatello's "David" can be seen in Leonardo's late paintings, particularly John the Baptist.[44][45]

Small devotional picture by Verrocchio, c. 1470

A prevalent tradition in Florence was the small altarpiece of the Virgin and Child. Many of these were created in tempera or glazed terracotta by the workshops of Filippo Lippi, Verrocchio and the prolific della Robbia family.[44] Leonardo's early Madonnas such as The Madonna with a carnation and The Benois Madonna followed this tradition while showing idiosyncratic departures, particularly in the case of the Benois Madonna in which the Virgin is set at an oblique angle to the picture space with the Christ Child at the opposite angle. This compositional theme was to emerge in Leonardo's later paintings such as The Virgin and Child with St. Anne.[11]

Leonardo was a contemporary of Botticelli, Domenico Ghirlandaio and Perugino, who were all slightly older than he was.[45] He would have met them at the workshop of Verrocchio, with whom they had associations, and at the Academy of the Medici.[11] Botticelli was a particular favourite of the Medici family, and thus his success as a painter was assured. Ghirlandaio and Perugino were both prolific and ran large workshops. They competently delivered commissions to well-satisfied patrons who appreciated Ghirlandaio's ability to portray the wealthy citizens of Florence within large religious frescoes, and Perugino's ability to deliver a multitude of saints and angels of unfailing sweetness and innocence.[44]

The Portinari Altarpiece, by Hugo van der Goes for a Florentine family

These three were among those commissioned to paint the walls of the Sistine Chapel, the work commencing with Perugino's employment in 1479. Leonardo was not part of this prestigious commission. His first significant commission, The Adoration of the Magi for the Monks of Scopeto, was never completed.[11]

In 1476, during the time of Leonardo's association with Verrocchio's workshop, the Portinari Altarpiece by Hugo van der Goes arrived in Florence, bringing new painterly techniques from Northern Europe which were to profoundly affect Leonardo, Ghirlandaio, Perugino and others.[45] In 1479, the Sicilian painter Antonello da Messina, who worked exclusively in oils, traveled north on his way to Venice, where the leading painter Giovanni Bellini adopted the technique of oil painting, quickly making it the preferred method in Venice. Leonardo was also later to visit Venice.[45][47]

Like the two contemporary architects Bramante and Antonio da Sangallo the Elder Leonardo experimented with designs for centrally planned churches, a number of which appear in his journals, as both plans and views, although none was ever realised.[45][50]

Lorenzo de' Medici between Antonio Pucci and Francesco Sassetti, with Giulio de' Medici, fresco by Ghirlandaio

Leonardo's political contemporaries were Lorenzo Medici (il Magnifico), who was three years older, and his younger brother Giuliano who was slain in the Pazzi Conspiracy in 1478. Ludovico il Moro who ruled Milan between 1479 and 1499 and to whom Leonardo was sent as ambassador from the Medici court, was also of Leonardo's age.[45]

With Alberti, Leonardo visited the home of the Medici and through them came to know the older Humanist philosophers of whom Marsiglio Ficino, proponent of Neo Platonism; Cristoforo Landino, writer of commentaries on Classical writings, and John Argyropoulos, teacher of Greek and translator of Aristotle were the foremost. Also associated with the Academy of the Medici was Leonardo's contemporary, the brilliant young poet and philosopher Pico della Mirandola.[45][47][51] Leonardo later wrote in the margin of a journal "The Medici made me and the Medici destroyed me." While it was through the action of Lorenzo that Leonardo received his employment at the court of Milan, it is not known exactly what Leonardo meant by this cryptic comment.[11]

Although usually named together as the three giants of the High Renaissance, Leonardo, Michelangelo and Raphael were not of the same generation. Leonardo was twenty-three when Michelangelo was born and thirty-one when Raphael was born.[45] Raphael only lived until the age of 37 and died in 1520, the year after Leonardo, but Michelangelo went on creating for another 45 years.[46][47]

Study for a portrait of Isabella d'Este (1500) Louvre

Personal life

Within Leonardo's lifetime, his extraordinary powers of invention, his "outstanding physical beauty", "infinite grace", "great strength and generosity", "regal spirit and tremendous breadth of mind" as described by Vasari,[52] as well as all other aspects of his life, attracted the curiosity of others. One such aspect is his respect for life evidenced by his vegetarianism and his habit, according to Vasari, of purchasing caged birds and releasing them.[53][54]
Leonardo had many friends who are now renowned either in their fields or for their historical significance. They included the mathematician Luca Pacioli,[55] with whom he collaborated on the book De Divina Proportione in the 1490s. Leonardo appears to have had no close relationships with women except for his friendship with Cecilia Gallerani and the two Este sisters, Beatrice and Isabella.[56] He drew a portrait of Isabella while on a journey which took him through Mantua, and which appears to have been used to create a painted portrait, now lost.[11]

Beyond friendship, Leonardo kept his private life secret. His sexuality has been the subject of satire, analysis, and speculation. This trend began in the mid-16th century and was revived in the 19th and 20th centuries, most notably by Sigmund Freud.[57] Leonardo's most intimate relationships were perhaps with his pupils Salai and Melzi. Melzi, writing to inform Leonardo's brothers of his death, described Leonardo's feelings for his pupils as both loving and passionate. It has been claimed since the 16th century that these relationships were of a sexual or erotic nature. Court records of 1476, when he was aged twenty-four, show that Leonardo and three other young men were charged with sodomy in an incident involving a well-known male prostitute. The charges were dismissed for lack of evidence, and there is speculation that since one of the accused, Lionardo de Tornabuoni, was related to Lorenzo de' Medici, the family exerted its influence to secure the dismissal.[58] Since that date much has been written about his presumed homosexuality and its role in his art, particularly in the androgyny and eroticism manifested in John the Baptist and Bacchus and more explicitly in a number of erotic drawings.[59]

John the Baptist. Salai is thought to have been the model.[60] (c. 1514)—Louvre

Assistants and pupils

Gian Giacomo Caprotti da Oreno, nicknamed Salai or Il Salaino ("The Little Unclean One" i.e., the devil), entered Leonardo's household in 1490. After only a year, Leonardo made a list of his misdemeanours, calling him "a thief, a liar, stubborn, and a glutton", after he had made off with money and valuables on at least five occasions and spent a fortune on clothes.[61] Nevertheless, Leonardo treated him with great indulgence, and he remained in Leonardo's household for the next thirty years.[62] Salai executed a number of paintings under the name of Andrea Salai, but although Vasari claims that Leonardo "taught him a great deal about painting",[39] his work is generally considered to be of less artistic merit than others among Leonardo's pupils, such as Marco d'Oggione and Boltraffio. In 1515, he painted a nude version of the Mona Lisa, known as Monna Vanna.[63] Salai owned the Mona Lisa at the time of his death in 1525, and in his will it was assessed at 505 lire, an exceptionally high valuation for a small panel portrait.[64]

In 1506, Leonardo took on another pupil, Count Francesco Melzi, the son of a Lombard aristocrat, who is considered to have been his favourite student. He travelled to France with Leonardo and remained with him until Leonardo's death.[11] Melzi inherited the artistic and scientific works, manuscripts, and collections of Leonardo and administered the estate.

Painting

Annunciation (1475–1480)—Uffizi, is thought to be Leonardo's earliest complete work

Despite the recent awareness and admiration of Leonardo as a scientist and inventor, for the better part of four hundred years his fame rested on his achievements as a painter and on a handful of works, either authenticated or attributed to him that have been regarded as among the masterpieces.[65]

These paintings are famous for a variety of qualities which have been much imitated by students and discussed at great length by connoisseurs and critics. Among the qualities that make Leonardo's work unique are the innovative techniques which he used in laying on the paint, his detailed knowledge of anatomy, light, botany and geology, his interest in physiognomy and the way in which humans register emotion in expression and gesture, his innovative use of the human form in figurative composition, and his use of the subtle gradation of tone. All these qualities come together in his most famous painted works, the Mona Lisa, the Last Supper and the Virgin of the Rocks.[66]

Unfinished painting of St. Jerome in the Wilderness, (c. 1480), Vatican

Early works

Leonardo's early works begin with the Baptism of Christ painted in conjunction with Verrocchio. Two other paintings appear to date from his time at the workshop, both of which are Annunciations. One is small, 59 centimetres (23 in) long and 14 centimetres (5.5 in) high. It is a "predella" to go at the base of a larger composition, in this case a painting by Lorenzo di Credi from which it has become separated. The other is a much larger work, 217 centimetres (85 in) long.[67] In both these Annunciations, Leonardo used a formal arrangement, such as in Fra Angelico's two well-known pictures of the same subject, of the Virgin Mary sitting or kneeling to the right of the picture, approached from the left by an angel in profile, with a rich flowing garment, raised wings and bearing a lily. Although previously attributed to Ghirlandaio, the larger work is now generally attributed to Leonardo.[68]

In the smaller picture Mary averts her eyes and folds her hands in a gesture that symbolised submission to God's will. In the larger picture, however, Mary is not submissive. The girl, interrupted in her reading by this unexpected messenger, puts a finger in her bible to mark the place and raises her hand in a formal gesture of greeting or surprise.[44] This calm young woman appears to accept her role as the Mother of God, not with resignation but with confidence. In this painting the young Leonardo presents the humanist face of the Virgin Mary, recognising humanity's role in God's incarnation.[nb 19]

Paintings of the 1480s


Virgin of the Rocks, National Gallery, London, demonstrates Leonardo's interest in nature

In the 1480s Leonardo received two very important commissions and commenced another work which was also of ground-breaking importance in terms of composition. Two of the three were never finished, and the third took so long that it was subject to lengthy negotiations over completion and payment. One of these paintings is that of St. Jerome in the Wilderness. Bortolon associates this picture with a difficult period of Leonardo's life, as evidenced in his diary: "I thought I was learning to live; I was only learning to die."[11]

Although the painting is barely begun, the composition can be seen and it is very unusual.[nb 20] Jerome, as a penitent, occupies the middle of the picture, set on a slight diagonal and viewed somewhat from above. His kneeling form takes on a trapezoid shape, with one arm stretched to the outer edge of the painting and his gaze looking in the opposite direction. J. Wasserman points out the link between this painting and Leonardo's anatomical studies.[70] Across the foreground sprawls his symbol, a great lion whose body and tail make a double spiral across the base of the picture space.
The other remarkable feature is the sketchy landscape of craggy rocks against which the figure is silhouetted.

The daring display of figure composition, the landscape elements and personal drama also appear in the great unfinished masterpiece, the Adoration of the Magi, a commission from the Monks of San Donato a Scopeto. It is a complex composition, of about 250 x 250 centimetres. Leonardo did numerous drawings and preparatory studies, including a detailed one in linear perspective of the ruined classical architecture which makes part of the backdrop to the scene. But in 1482 Leonardo went off to Milan at the behest of Lorenzo de' Medici in order to win favour with Ludovico il Moro, and the painting was abandoned.[10][68]

The third important work of this period is the Virgin of the Rocks which was commissioned in Milan for the Confraternity of the Immaculate Conception. The painting, to be done with the assistance of the de Predis brothers, was to fill a large complex altarpiece, already constructed.[71] Leonardo chose to paint an apocryphal moment of the infancy of Christ when the infant John the Baptist, in protection of an angel, met the Holy Family on the road to Egypt. In this scene, as painted by Leonardo, John recognizes and worships Jesus as the Christ. The painting demonstrates an eerie beauty as the graceful figures kneel in adoration around the infant Christ in a wild landscape of tumbling rock and whirling water.[72] While the painting is quite large, about 200 × 120 centimetres, it is not nearly as complex as the painting ordered by the monks of St Donato, having only four figures rather than about fifty and a rocky landscape rather than architectural details. The painting was eventually finished; in fact, two versions of the painting were finished, one which remained at the chapel of the Confraternity and the other which Leonardo carried away to France. But the Brothers did not get their painting, or the de Predis their payment, until the next century.[17][30]

Paintings of the 1490s

Leonardo's most famous painting of the 1490s is The Last Supper, painted for the refectory of the Convent of Santa Maria della Grazie in Milan. The painting represents the last meal shared by Jesus with his disciples before his capture and death. It shows specifically the moment when Jesus has just said "one of you will betray me". Leonardo tells the story of the consternation that this statement caused to the twelve followers of Jesus.[17]

The novelist Matteo Bandello observed Leonardo at work and wrote that some days he would paint from dawn till dusk without stopping to eat and then not paint for three or four days at a time.[73] This was beyond the comprehension of the prior of the convent, who hounded him until Leonardo asked Ludovico to intervene. Vasari describes how Leonardo, troubled over his ability to adequately depict the faces of Christ and the traitor Judas, told the Duke that he might be obliged to use the prior as his model.[74]

When finished, the painting was acclaimed as a masterpiece of design and characterisation,[75] but it deteriorated rapidly, so that within a hundred years it was described by one viewer as "completely ruined".[76] Leonardo, instead of using the reliable technique of fresco, had used tempera over a ground that was mainly gesso, resulting in a surface which was subject to mold and to flaking.[77] Despite this, the painting has remained one of the most reproduced works of art, countless copies being made in every medium from carpets to cameos.

Paintings of the 1500s


Mona Lisa or La Gioconda (1503–1505/1507)—Louvre, Paris, France

Among the works created by Leonardo in the 16th century is the small portrait known as the Mona Lisa or "la Gioconda", the laughing one. In the present era it is arguably the most famous painting in the world. Its fame rests, in particular, on the elusive smile on the woman's face, its mysterious quality brought about perhaps by the fact that the artist has subtly shadowed the corners of the mouth and eyes so that the exact nature of the smile cannot be determined. The shadowy quality for which the work is renowned came to be called "sfumato" or Leonardo's smoke. Vasari, who is generally thought to have known the painting only by repute, said that "the smile was so pleasing that it seemed divine rather than human; and those who saw it were amazed to find that it was as alive as the original".[78][nb 21]

Other characteristics found in this work are the unadorned dress, in which the eyes and hands have no competition from other details, the dramatic landscape background in which the world seems to be in a state of flux, the subdued colouring and the extremely smooth nature of the painterly technique, employing oils, but laid on much like tempera and blended on the surface so that the brushstrokes are indistinguishable.[nb 22] Vasari expressed the opinion that the manner of painting would make even "the most confident master ... despair and lose heart."[81] The perfect state of preservation and the fact that there is no sign of repair or overpainting is rare in a panel painting of this date.[82]

In the painting Virgin and Child with St. Anne the composition again picks up the theme of figures in a landscape which Wasserman describes as "breathtakingly beautiful"[83] and harkens back to the St Jerome picture with the figure set at an oblique angle. What makes this painting unusual is that there are two obliquely set figures superimposed. Mary is seated on the knee of her mother, St Anne. She leans forward to restrain the Christ Child as he plays roughly with a lamb, the sign of his own impending sacrifice.[17] This painting, which was copied many times, influenced Michelangelo, Raphael, and Andrea del Sarto,[84] and through them Pontormo and Correggio. The trends in composition were adopted in particular by the Venetian painters Tintoretto and Veronese.

Drawings

Leonardo was not a prolific painter, but he was a most prolific draftsman, keeping journals full of small sketches and detailed drawings recording all manner of things that took his attention. As well as the journals there exist many studies for paintings, some of which can be identified as preparatory to particular works such as The Adoration of the Magi, The Virgin of the Rocks and The Last Supper.[85] His earliest dated drawing is a Landscape of the Arno Valley, 1473, which shows the river, the mountains, Montelupo Castle and the farmlands beyond it in great detail.[11][85]

Among his famous drawings are the Vitruvian Man, a study of the proportions of the human body, the Head of an Angel, for The Virgin of the Rocks in the Louvre, a botanical study of Star of Bethlehem and a large drawing (160×100 cm) in black chalk on coloured paper of The Virgin and Child with St. Anne and St. John the Baptist in the National Gallery, London.[85] This drawing employs the subtle sfumato technique of shading, in the manner of the Mona Lisa. It is thought that Leonardo never made a painting from it, the closest similarity being to The Virgin and Child with St. Anne in the Louvre.[86]

Other drawings of interest include numerous studies generally referred to as "caricatures" because, although exaggerated, they appear to be based upon observation of live models. Vasari relates that if Leonardo saw a person with an interesting face he would follow them around all day observing them.[87] There are numerous studies of beautiful young men, often associated with Salai, with the rare and much admired facial feature, the so-called "Grecian profile".[nb 23] These faces are often contrasted with that of a warrior.[85] Salai is often depicted in fancy-dress costume. Leonardo is known to have designed sets for pageants with which these may be associated. Other, often meticulous, drawings show studies of drapery. A marked development in Leonardo's ability to draw drapery occurred in his early works. Another often-reproduced drawing is a macabre sketch that was done by Leonardo in Florence in 1479 showing the body of Bernardo Baroncelli, hanged in connection with the murder of Giuliano, brother of Lorenzo de' Medici, in the Pazzi Conspiracy.[85] With dispassionate integrity Leonardo has registered in neat mirror writing the colours of the robes that Baroncelli was wearing when he died.

Observation and invention

Journals and notes

Renaissance humanism recognized no mutually exclusive polarities between the sciences and the arts, and Leonardo's studies in science and engineering are as impressive and innovative as his artistic work.[17] These studies were recorded in 13,000 pages of notes and drawings, which fuse art and natural philosophy (the forerunner of modern science), made and maintained daily throughout Leonardo's life and travels, as he made continual observations of the world around him.[17]
Leonardo's writings are mostly in mirror-image cursive. The reason may have been more a practical expediency than for reasons of secrecy as is often suggested. Since Leonardo wrote with his left hand, it is probable that it was easier for him to write from right to left.[nb 24]

A page showing Leonardo's study of a foetus in the womb (c. 1510) Royal Library, Windsor Castle

His notes and drawings display an enormous range of interests and preoccupations, some as mundane as lists of groceries and people who owed him money and some as intriguing as designs for wings and shoes for walking on water. There are compositions for paintings, studies of details and drapery, studies of faces and emotions, of animals, babies, dissections, plant studies, rock formations, whirlpools, war machines, flying machines and architecture.[17]

These notebooks—originally loose papers of different types and sizes, distributed by friends after his death—have found their way into major collections such as the Royal Library at Windsor Castle, the Louvre, the Biblioteca Nacional de España, the Victoria and Albert Museum, the Biblioteca Ambrosiana in Milan which holds the twelve-volume Codex Atlanticus, and British Library in London which has put a selection from the Codex Arundel (BL Arundel MS 263) online.[88] The Codex Leicester is the only major scientific work of Leonardo's in private hands. It is owned by Bill Gates and is displayed once a year in different cities around the world.

Leonardo's notes appear to have been intended for publication because many of the sheets have a form and order that would facilitate this. In many cases a single topic, for example, the heart or the human fetus, is covered in detail in both words and pictures on a single sheet.[89][nb 25] Why they were not published within Leonardo's lifetime is unknown.[17]

Scientific studies


Leonardo's approach to science was an observational one: he tried to understand a phenomenon by describing and depicting it in utmost detail and did not emphasize experiments or theoretical explanation. Since he lacked formal education in Latin and mathematics, contemporary scholars mostly ignored Leonardo the scientist, although he did teach himself Latin. In the 1490s he studied mathematics under Luca Pacioli and prepared a series of drawings of regular solids in a skeletal form to be engraved as plates for Pacioli's book De Divina Proportione, published in 1509.[17]

It appears that from the content of his journals he was planning a series of treatises to be published on a variety of subjects. A coherent treatise on anatomy was said to have been observed during a visit by Cardinal Louis 'D' Aragon's secretary in 1517.[90] Aspects of his work on the studies of anatomy, light and the landscape were assembled for publication by his pupil Francesco Melzi and eventually published as Treatise on Painting by Leonardo da Vinci in France and Italy in 1651 and Germany in 1724,[91] with engravings based upon drawings by the Classical painter Nicolas Poussin.[92] According to Arasse, the treatise, which in France went into 62 editions in fifty years, caused Leonardo to be seen as "the precursor of French academic thought on art".[17]

While Leonardo's experimentation followed clear scientific methods, a recent and exhaustive analysis of Leonardo as a scientist by Frtijof Capra argues that Leonardo was a fundamentally different kind of scientist from Galileo, Newton and other scientists who followed him in that, as a Renaissance Man, his theorising and hypothesising integrated the arts and particularly painting.[93]

Anatomical study of the arm, (c. 1510)

Anatomy

Leonardo's formal training in the anatomy of the human body began with his apprenticeship to Andrea del Verrocchio, who insisted that all his pupils learn anatomy. As an artist, he quickly became master of topographic anatomy, drawing many studies of muscles, tendons and other visible anatomical features.

As a successful artist, he was given permission to dissect human corpses at the Hospital of Santa Maria Nuova in Florence and later at hospitals in Milan and Rome. From 1510 to 1511 he collaborated in his studies with the doctor Marcantonio della Torre. Leonardo made over 240 detailed drawings and wrote about 13,000 words towards a treatise on anatomy.[94] These papers were left to his heir, Francesco Melzi, for publication, a task of overwhelming difficulty because of its scope and Leonardo's idiosyncratic writing.[95] It was left incomplete at the time of Melzi's death more than fifty years later, with only a small amount of the material on anatomy included in Leonardo's Treatise on painting, published in France in 1632.[17][95] During the time that Melzi was ordering the material into chapters for publication, they were examined by a number of anatomists and artists, including Vasari, Cellini and Albrecht Dürer who made a number of drawings from them.[95]

Leonardo's anatomical drawings include many studies of the human skeleton and its parts, and studies muscles and sinews. He studied the mechanical functions of the skeleton and the muscular forces that are applied to it in a manner that prefigured the modern science of biomechanics.[96] He drew the heart and vascular system, the sex organs and other internal organs, making one of the first scientific drawings of a fetus in utero.[85] The drawings and notation are far ahead of their time, and if published, would undoubtedly have made a major contribution to medical science.[94][97]

As an artist, Leonardo also closely observed and recorded the effects of age and of human emotion on the physiology, studying in particular the effects of rage. He also drew many figures who had significant facial deformities or signs of illness.[17][85] Leonardo also studied and drew the anatomy of many animals, dissecting cows, birds, monkeys, bears, and frogs, and comparing in his drawings their anatomical structure with that of humans. He also made a number of studies of horses.[85]

Engineering and inventions


A design for a flying machine, (c. 1488) Institut de France, Paris

During his lifetime Leonardo was valued as an engineer. In a letter to Ludovico il Moro he claimed to be able to create all sorts of machines both for the protection of a city and for siege. When he fled to Venice in 1499 he found employment as an engineer and devised a system of moveable barricades to protect the city from attack. He also had a scheme for diverting the flow of the Arno River, a project on which Niccolò Machiavelli also worked.[98][99] Leonardo's journals include a vast number of inventions, both practical and impractical. They include musical instruments, a mechanical knight, hydraulic pumps, reversible crank mechanisms, finned mortar shells, and a steam cannon.[11][17]

In 1502, Leonardo produced a drawing of a single span 720-foot (220 m) bridge as part of a civil engineering project for Ottoman Sultan Beyazid II of Constantinople. The bridge was intended to span an inlet at the mouth of the Bosporus known as the Golden Horn. Beyazid did not pursue the project because he believed that such a construction was impossible. Leonardo's vision was resurrected in 2001 when a smaller bridge based on his design was constructed in Norway.[100][101]

For much of his life, Leonardo was fascinated by the phenomenon of flight, producing many studies of the flight of birds, including his c. 1505 Codex on the Flight of Birds, as well as plan for several flying machines, including a flapping ornithopter and a machine with a helical rotor.[17] The British television station Channel Four commissioned a documentary Leonardo's Dream Machines, for broadcast in 2003. Leonardo's designs for machines such as a parachute, and giant crossbow were interpreted, constructed and tested.[102][103] Some of those designs proved a success, whilst others fared less well when practically tested.

Fame and reputation

Francis I of France receiving the last breath of Leonardo da Vinci, by Ingres, 1818

Within Leonardo's own lifetime his fame was such that the King of France carried him away like a trophy and was claimed to have supported him in his old age and held him in his arms as he died. Interest in Leonardo has never diminished. The crowds still queue to see his most famous artworks, T-shirts bear his most famous drawing, and writers continue to marvel at his genius and speculate about his private life and, particularly, about what one so intelligent actually believed in.[17]
Giorgio Vasari, in the enlarged edition of Lives of the Artists, 1568,[104] introduced his chapter on Leonardo da Vinci with the following words:
In the normal course of events many men and women are born with remarkable talents; but occasionally, in a way that transcends nature, a single person is marvellously endowed by Heaven with beauty, grace and talent in such abundance that he leaves other men far behind, all his actions seem inspired and indeed everything he does clearly comes from God rather than from human skill. Everyone acknowledged that this was true of Leonardo da Vinci, an artist of outstanding physical beauty, who displayed infinite grace in everything that he did and who cultivated his genius so brilliantly that all problems he studied he solved with ease.

Statue of Leonardo in Amboise

The continued admiration that Leonardo commanded from painters, critics and historians is reflected in many other written tributes. Baldassare Castiglione, author of Il Cortegiano ("The Courtier"), wrote in 1528: "... Another of the greatest painters in this world looks down on this art in which he is unequalled ..."[105] while the biographer known as "Anonimo Gaddiano" wrote, c. 1540: "His genius was so rare and universal that it can be said that nature worked a miracle on his behalf ...".[106]

The 19th century brought a particular admiration for Leonardo's genius, causing Henry Fuseli to write in 1801: "Such was the dawn of modern art, when Leonardo da Vinci broke forth with a splendour that distanced former excellence: made up of all the elements that constitute the essence of genius ..."[107] This is echoed by A. E. Rio who wrote in 1861: "He towered above all other artists through the strength and the nobility of his talents."[108]

By the 19th century, the scope of Leonardo's notebooks was known, as well as his paintings. Hippolyte Taine wrote in 1866: "There may not be in the world an example of another genius so universal, so incapable of fulfilment, so full of yearning for the infinite, so naturally refined, so far ahead of his own century and the following centuries."[109] Art historian Bernard Berenson wrote in 1896: "Leonardo is the one artist of whom it may be said with perfect literalness: Nothing that he touched but turned into a thing of eternal beauty. Whether it be the cross section of a skull, the structure of a weed, or a study of muscles, he, with his feeling for line and for light and shade, forever transmuted it into life-communicating values."[110]

The interest in Leonardo's genius has continued unabated; experts study and translate his writings, analyse his paintings using scientific techniques, argue over attributions and search for works which have been recorded but never found.[111] Liana Bortolon, writing in 1967, said: "Because of the multiplicity of interests that spurred him to pursue every field of knowledge ... Leonardo can be considered, quite rightly, to have been the universal genius par excellence, and with all the disquieting overtones inherent in that term. Man is as uncomfortable today, faced with a genius, as he was in the 16th century. Five centuries have passed, yet we still view Leonardo with awe."[11]

List of unsolved problems in physics



From Wikipedia, the free encyclopedia

Some of the major unsolved problems in physics are theoretical, meaning that existing theories seem incapable of explaining a certain observed phenomenon or experimental result. The others are experimental, meaning that there is a difficulty in creating an experiment to test a proposed theory or investigate a phenomenon in greater detail.

Unsolved problems by subfield

The following is a list of unsolved problems grouped into broad area of physics.[1]

Cosmology, and general relativity

Cosmic inflation
Is the theory of cosmic inflation correct, and, if so, what are the details of this epoch? What is the hypothetical inflaton field giving rise to inflation? If inflation happened at one point, is it self-sustaining through inflation of quantum-mechanical fluctuations, and thus ongoing in some extremely distant place?[2]
Horizon problem
Why is the distant universe so homogeneous when the Big Bang theory seems to predict larger measurable anisotropies of the night sky than those observed? Cosmological inflation is generally accepted as the solution, but are other possible explanations such as a variable speed of light more appropriate?[3]
Electroweak horizon problem
Why aren't there obvious large-scale discontinuities in the electroweak vacuum if distant parts of the observable universe were causally separate when the electroweak epoch ended? Standard cosmological inflation models have inflation cease well before electroweak symmetry breaking occurs, so it is not at all clear how inflation could prevent such discontinuities.[4]
Future of the universe
Is the universe heading towards a Big Freeze, a Big Rip, a Big Crunch, or a Big Bounce? Or is it part of an infinitely recurring cyclic model?
Gravitational wave
Can gravitational waves be directly detected?[5][6]
Baryon asymmetry
Why is there far more matter than antimatter in the observable universe?
Cosmological constant problem
Why does the zero-point energy of the vacuum not cause a large cosmological constant? What cancels it out?

Estimated distribution of dark matter and dark energy in the universe
Dark matter
What is the identity of dark matter?[3] Is it a particle? Is it the lightest superpartner (LSP)? Do the phenomena attributed to dark matter point not to some form of matter but actually to an extension of gravity?
Dark energy
What is the cause of the observed accelerated expansion (de Sitter phase) of the Universe? Why is the energy density of the dark energy component of the same magnitude as the density of matter at present when the two evolve quite differently over time; could it be simply that we are observing at exactly the right time? Is dark energy a pure cosmological constant or are models of quintessence such as phantom energy applicable?
Dark flow
Is a non-spherically symmetric gravitational pull from outside the observable Universe responsible for some of the observed motion of large objects such as galactic clusters in the universe?
Ecliptic alignment of CMB anisotropy
Some large features of the microwave sky at distances of over 13 billion light years appear to be aligned with both the motion and orientation of the solar system. Is this due to systematic errors in processing, contamination of results by local effects, or an unexplained violation of the Copernican principle?
Shape of the Universe
What is the 3-manifold of comoving space, i.e. of a comoving spatial section of the Universe, informally called the "shape" of the Universe? Neither the curvature nor the topology is presently known, though the curvature is known to be "close" to zero on observable scales. The cosmic inflation hypothesis suggests that the shape of the Universe may be unmeasurable, but, since 2003, Jean-Pierre Luminet, et al., and other groups have suggested that the shape of the Universe may be the Poincaré dodecahedral space. Is the shape unmeasurable; the Poincaré space; or another 3-manifold?

Quantum gravity

Vacuum catastrophe
Why does the predicted mass of the quantum vacuum have little effect on the expansion of the universe?
Quantum gravity
Can quantum mechanics and general relativity be realized as a fully consistent theory (perhaps as a quantum field theory)?[7] Is spacetime fundamentally continuous or discrete? Would a consistent theory involve a force mediated by a hypothetical graviton, or be a product of a discrete structure of spacetime itself (as in loop quantum gravity)? Are there deviations from the predictions of general relativity at very small or very large scales or in other extreme circumstances that flow from a quantum gravity theory?
Black holes, black hole information paradox, and black hole radiation
Do black holes produce thermal radiation, as expected on theoretical grounds? Does this radiation contain information about their inner structure, as suggested by Gauge-gravity duality, or not, as implied by Hawking's original calculation? If not, and black holes can evaporate away, what happens to the information stored in them (quantum mechanics does not provide for the destruction of information)? Or does the radiation stop at some point leaving black hole remnants? Is there another way to probe their internal structure somehow, if such a structure even exists?
Extra dimensions
Does nature have more than four spacetime dimensions? If so, what is their size? Are dimensions a fundamental property of the universe or an emergent result of other physical laws? Can we experimentally observe evidence of higher spatial dimensions?
The cosmic censorship hypothesis and the chronology protection conjecture
Can singularities not hidden behind an event horizon, known as "naked singularities", arise from realistic initial conditions, or is it possible to prove some version of the "cosmic censorship hypothesis" of Roger Penrose which proposes that this is impossible?[8] Similarly, will the closed timelike curves which arise in some solutions to the equations of general relativity (and which imply the possibility of backwards time travel) be ruled out by a theory of quantum gravity which unites general relativity with quantum mechanics, as suggested by the "chronology protection conjecture" of Stephen Hawking?
Locality
Are there non-local phenomena in quantum physics? If they exist, are non-local phenomena limited to the entanglement revealed in the violations of the Bell Inequalities, or can information and conserved quantities also move in a non-local way? Under what circumstances are non-local phenomena observed? What does the existence or absence of non-local phenomena imply about the fundamental structure of spacetime? How does this relate to quantum entanglement? How does this elucidate the proper interpretation of the fundamental nature of quantum physics?

High-energy physics/particle physics


A simulation of how a detection of the Higgs particle would appear in the CMS detector at CERN
Higgs mechanism
Are the branching ratios of the Higgs boson consistent with the standard model? Is there only one type of Higgs boson?
Hierarchy problem
Why is gravity such a weak force? It becomes strong for particles only at the Planck scale, around 1019 GeV, much above the electroweak scale (100 GeV, the energy scale dominating physics at low energies). Why are these scales so different from each other? What prevents quantities at the electroweak scale, such as the Higgs boson mass, from getting quantum corrections on the order of the Planck scale? Is the solution supersymmetry, extra dimensions, or just anthropic fine-tuning?
Magnetic monopoles
Did particles that carry "magnetic charge" exist in some past, higher-energy epoch? If so, do any remain today? (Paul Dirac showed the existence of some types of magnetic monopoles would explain charge quantization.)[9]
Proton decay and spin crisis
Is the proton fundamentally stable? Or does it decay with a finite lifetime as predicted by some extensions to the standard model?[10] How do the quarks and gluons carry the spin of protons?[11]
Supersymmetry
Is spacetime supersymmetry realized at TeV scale? If so, what is the mechanism of supersymmetry breaking? Does supersymmetry stabilize the electroweak scale, preventing high quantum corrections? Does the lightest supersymmetric particle (LSP) comprise dark matter?
Generations of matter
Why are there three generations of quarks and leptons? Is there a theory that can explain the masses of particular quarks and leptons in particular generations from first principles (a theory of Yukawa couplings)?
Electroweak symmetry breaking
What is the mechanism responsible for breaking the electroweak gauge symmetry, giving mass to the W and Z bosons? Is it the simple Higgs mechanism of the Standard Model,[12] or does nature make use of strong dynamics in breaking electroweak symmetry, as proposed by Technicolor?
Neutrino mass
What is the mass of neutrinos, whether they follow Dirac or Majorana statistics? Is mass hierarchy normal or inverted? Is the CP violating phase 0?[13][14][15]
Color confinement
Why has there never been measured a free quark or gluon, but only objects that are built out of them, like mesons and baryons? How does this phenomenon emerge from QCD?
Strong CP problem and axions
Why is the strong nuclear interaction invariant to parity and charge conjugation? Is Peccei–Quinn theory the solution to this problem?
Anomalous magnetic dipole moment
Why is the experimentally measured value of the muon's anomalous magnetic dipole moment ("muon g-2") significantly different from the theoretically predicted value of that physical constant?[16]
Proton size puzzle
What is the electric charge radius of the proton? and how does it differ from gluonic charge?

Astronomy and astrophysics


Relativistic jet. The environment around the AGN where the relativistic plasma is collimated into jets which escape along the pole of the supermassive black hole
Astrophysical jet
Why do the accretion discs surrounding certain astronomical objects, such as the nuclei of active galaxies, emit relativistic jets along their polar axes?[17] Why are there quasi-periodic oscillations in many accretion discs?[18] Why does the period of these oscillations scale as the inverse of the mass of the central object?[19] Why are there sometimes overtones, and why do these appear at different frequency ratios in different objects?[20]
Coronal heating problem
Why is the Sun's corona (atmosphere layer) so much hotter than the Sun's surface? Why is the magnetic reconnection effect many orders of magnitude faster than predicted by standard models?
Diffuse interstellar bands
What is responsible for the numerous interstellar absorption lines detected in astronomical spectra? Are they molecular in origin, and if so which molecules are responsible for them? How do they form?
Gamma ray bursts
How do these short-duration high-intensity bursts originate?[12]
Supermassive black holes
What is the origin of the M-sigma relation between supermassive black hole mass and galaxy velocity dispersion?[21] How did the most distant quasars grow their supermassive black holes up to 109 solar masses so early in the history of the Universe?

Rotation curve of a typical spiral galaxy: predicted (A) and observed (B). Can the discrepancy between the curves be attributed to dark matter?
Kuiper cliff
Why does the number of objects in the Solar System's Kuiper belt fall off rapidly and unexpectedly beyond a radius of 50 astronomic units?
Flyby anomaly
Why is the observed energy of satellites flying by Earth sometimes different by a minute amount from the value predicted by theory?
Galaxy rotation problem
Is dark matter responsible for differences in observed and theoretical speed of stars revolving around the center of galaxies, or is it something else?
Supernovae
What is the exact mechanism by which an implosion of a dying star becomes an explosion?
Ultra-high-energy cosmic ray
[3] Why is it that some cosmic rays appear to possess energies that are impossibly high (the so-called OMG particle), given that there are no sufficiently energetic cosmic ray sources near the Earth? Why is it that (apparently) some cosmic rays emitted by distant sources have energies above the Greisen–Zatsepin–Kuzmin limit?[3][12]
Rotation rate of Saturn
Why does the magnetosphere of Saturn exhibit a (slowly changing) periodicity close to that at which the planet's clouds rotate? What is the true rotation rate of Saturn's deep interior?[22]
Origin of magnetar magnetic field
What is the origin of magnetar magnetic field?
Photon underproduction crisis
Why do galaxies and quasars produce about 5 times less ultraviolet light than expected in the low-redshift universe?
Space roar
Why is space roar six times louder than expected? What is the source of space roar?
Age-metallicity relation in the Galactic disk
Is there a universal age-metallicity relation (AMR) in the Galactic disk (thin and thick disk)? While in the local (primarily thin) disk there is no evidence of a strong AMR,[23] a sample of 229 nearby thick disk stars has been used to investigate the existence of an age-metallicity relation in the Galactic thick disk. The results indicate that there is indeed an age-metallicity relation present in the thick disk.[24][25]
The lithium problem
Why is there a discrepancy between the amount of lithium-7 predicted to be produced in Big Bang nucleosynthesis and the amount observed in very old stars?[26]
Solar wind interaction with comets
In 2007 the Ulysses spacecraft passed through the tail of comet C/2006 P1 (McNaught) and found surprising results concerning the interaction of the solar wind with the tail.
Ultraluminous pulsar
The ultraluminous X-ray source M82 X-2 was thought to be a black hole, but in October 2014 data from NASA's space-based X-ray telescope NuStar indicated that M82 X-2 is a pulsar many times brighter than the Eddington limit.

Nuclear physics


The "island of stability" in the proton vs. neutron number plot for heavy nuclei
Quantum chromodynamics
What are the phases of strongly interacting matter, and what roles do they play in the evolution of cosmos? What is the detailed partonic structure of the nucleons? What does QCD predict for the properties of strongly interacting matter? What determines the key features of QCD, and what is their relation to the nature of gravity and spacetime? Do glueballs exist? Do gluons acquire mass dynamically despite having a zero rest mass, within hadrons? Does QCD truly lack CP-violations? Do gluons saturate when their occupation number is large? Do gluons form a dense system called Color Glass Condensate? What are the signatures and evidences for the Balitsky-Fadin-Kuarev-Lipatov, Balitsky-Kovchegov, Catani-Ciafaloni-Fiorani-Marchesini evolution equations?
Nuclei and Nuclear astrophysics
What is the nature of the nuclear force that binds protons and neutrons into stable nuclei and rare isotopes? What is the origin of simple patterns[which?] in complex nuclei? What is the nature of exotic excitations in nuclei at the frontiers of stability and their role in stellar processes? What is the nature of neutron stars and dense nuclear matter? What is the origin of the elements in the cosmos? What are the nuclear reactions that drive stars and stellar explosions?
Plasma Physics and Fusion Power
Fusion energy may potentially provide power from abundant resource (e.g. Hydrogen) without the type of radioactive waste that fission energy currently produces. However, can ionized gases (plasma) be confined long enough and at a high enough temperature to create fusion power? What kinds of advances in material science must be made?

Atomic, molecular and optical physics

Hydrogen atom
What is the solution to the Schrödinger equation for the hydrogen atom in arbitrary electric and magnetic fields?[27]
Muonic hydrogen
Is the radius of muonic hydrogen inconsistent with the radius of ordinary hydrogen?
Laser cooling
Can molecules be cooled down by laser cooling as has been done to atoms?
Abraham–Minkowski controversy
What's the momentum of photons in optical media?

Condensed matter physics


A sample of a cuprate superconductor (specifically BSCCO). The mechanism for superconductivity of these materials is unknown.
High-temperature superconductors
What is the mechanism that causes certain materials to exhibit superconductivity at temperatures much higher than around 25 kelvin? Is it possible to make a material that is a superconductor at room temperature?[12]
Amorphous solids
What is the nature of the glass transition between a fluid or regular solid and a glassy phase? What are the physical processes giving rise to the general properties of glasses and the glass transition?[28][29]
Cryogenic electron emission
Why does the electron emission in the absence of light increase as the temperature of a photomultiplier is decreased?[30][31]
Sonoluminescence
What causes the emission of short bursts of light from imploding bubbles in a liquid when excited by sound?[32][dated info]
Turbulence
Is it possible to make a theoretical model to describe the statistics of a turbulent flow (in particular, its internal structures)?[12] Also, under what conditions do smooth solutions to the Navier–Stokes equations exist? This problem is also listed as one of the Millennium Prize Problems in mathematics. Alfvénic turbulence in the solar wind and the turbulence in solar flares, coronal mass ejections, and magnetospheric substorms are major unsolved problems in space plasma physics.[33]
Topological order
Is topological order stable at non-zero temperature? Equivalently, is it possible to have three-dimensional self-correcting quantum memory?[34]
Fractional Hall effect
What mechanism explains the existence of the ν=5/2 state in the fractional quantum Hall effect? Does it describe quasiparticles with non-Abelian fractional statistics?[35]
Bose–Einstein condensation
How do we rigorously prove the existence of Bose–Einstein condensates for general interacting systems?[36]

Magnetoresistance in a ν=8/5 fractional quantum Hall state.
Liquid crystals
Can the nematic to smectic (A) phase transition in liquid crystal states be characterized as a universal phase transition?[37][38]
Semiconductor nanocrystals
What is the cause of the nonparabolicity of the energy-size dependence for the lowest optical absorption transition of quantum dots?[39]
Electronic band structure
Why can band gaps not accurately be calculated?

Biophysics

Stochasticity and robustness to noise in gene expression
How do genes govern our body, withstanding different external pressures and internal stochasticity? Certain models exist for genetic processes, but we are far from understanding the whole picture, in particular in development where gene expression must be tightly regulated.
Quantitative study of the immune system
What are the quantitative properties of immune responses? What are the basic building blocks of immune system networks? What roles are played by stochasticity?
Homochirality
What is the origin of the preponderance of specific enantiomers in biochemical systems?

Other problems

Entropy (arrow of time)
Why did the universe have such low entropy in the past, resulting in the distinction between past and future and the second law of thermodynamics?[12] Why are CP violations observed in certain weak force decays, but not elsewhere? Are CP violations somehow a product of the Second Law of Thermodynamics, or are they a separate arrow of time? Are there exceptions to the principle of causality? Is there a single possible past? Is the present moment physically distinct from the past and future or is it merely an emergent property of consciousness? Why does time have a direction?
Interpretation of quantum mechanics
How does the quantum description of reality, which includes elements such as the superposition of states and wavefunction collapse or quantum decoherence, give rise to the reality we perceive? Another way of stating this is the Measurement problem – what constitutes a "measurement" which causes the wave function to collapse into a definite state? Unlike classical physical processes, some quantum mechanical processes (such as quantum teleportation arising from quantum entanglement) cannot be simultaneously "local", "causal" and "real", but it is not obvious which of these properties must be sacrificed or if an attempt to describe quantum mechanical processes in these senses is a category error that doesn't even make sense to talk about if one properly understands quantum mechanics.
Theory of everything ("Grand Unification Theory")
Is there a theory which explains the values of all fundamental physical constants?[12] Is the theory string theory? Is there a theory which explains why the gauge groups of the standard model are as they are, why observed space-time has 3 spatial dimensions and 1 dimension of time, and why all laws of physics are as they are? Do "fundamental physical constants" vary over time? Are any of the particles in the standard model of particle physics actually composite particles too tightly bound to observe as such at current experimental energies? Are there fundamental particles that have not yet been observed, and, if so, which ones are they and what are their properties? Are there unobserved fundamental forces implied by a theory that explains other unsolved problems in physics?
Yang–Mills theory
Given an arbitrary compact gauge group, does a non-trivial quantum Yang–Mills theory with a finite mass gap exist? This problem is also listed as one of the Millennium Prize Problems in mathematics.
Physical information
Are there physical phenomena, such as wave function collapse or black holes, which irrevocably destroy information about their prior states? How is quantum information stored as a state of a quantum system?
Quantum Computation
Is David Deutsch's notion of a universal quantum computer sufficient to efficiently simulate an arbitrary physical system?[40]
Dimensionless physical constant
At the present time, the values of the dimensionless physical constants cannot be calculated; they are determined only by physical measurement.[41] What is the minimum number of dimensionless physical constants from which all other dimensionless physical constants can be derived? Are dimensionful physical constants necessary at all?

Problems solved in recent decades

Ball lightning (2014)
In January 2014, scientists from Northwest Normal University in Lanzhou, China, published the results of recordings made in July 2012 of the optical spectrum of what was thought to be natural ball lightning made during the study of ordinary cloud–ground lightning on China's Qinghai Plateau.[42][43] At a distance of 900 m (3,000 ft), a total of 1.3 seconds of digital video of the ball lightning and its spectrum was made, from the formation of the ball lightning after the ordinary lightning struck the ground, up to the optical decay of the phenomenon. The recorded ball lightning is believed to be vaporized soil elements that then rapidly oxidizes in the atmosphere. The nature of the true theory is still not clear.[43]
Hipparcos anomaly (2012)
The actual distance to the Pleiades - the High Precision Parallax Collecting Satellite (Hipparcos) measured the parallax of the Pleiades and determined a distance of 385 light years. This was significantly different from other measurements made by means of actual to apparent brightness measurement or absolute magnitude. The anomaly was due to the use of a weighted mean when there is a correlation between distances and distance errors for stars in clusters. It is resolved by using an unweighted mean. There is no systematic bias in the Hipparcos data when it comes to star clusters.[44]
Pioneer anomaly (2012)
There was a deviation in the predicted accelerations of the Pioneer spacecraft as they left the Solar System.[3][12] It is believed that this is a result of previously unaccounted-for thermal recoil force.[45][46]
Long-duration gamma ray bursts (2003)
Long-duration bursts are associated with the deaths of massive stars in a specific kind of supernova-like event commonly referred to as a collapsar. However, there are also long-duration GRBs that show evidence against an associated supernova, such as the Swift event GRB 060614.
Solar neutrino problem (2002)
Solved by a new understanding of neutrino physics, requiring a modification of the Standard Model of particle physics—specifically, neutrino oscillation.
Age Crisis (1990s)
The estimated age of the universe was around 3 to 8 billion years younger than estimates of the ages of the oldest stars in our galaxy. Better estimates for the distances to the stars, and the recognition of the accelerating expansion of the universe, reconciled the age estimates. (This assertion is being contested. Justification has been posted on Age Crisis page).
Quasars (1980s)
The nature of quasars was not understood for decades.[47] They are now accepted as a type of active galaxy where the enormous energy output results from matter falling into a massive black hole in the center of the galaxy.[48]

Subatomic particle

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