<A>
polarized light-rays: *
Light is the interaction of electric & magnetic fields travelling through space; these 2 fields are always perpendicular to each other with the direction of travel being perpendicular to both. These electric & magnetic vibrations can occur in numerous planes. A light wave vibrating in more than 1 plane is un-polarized. Light emitted by the sun, a lamp or tube light are all un-polarised. In the image below, the direction of propagation is constant, but the planes on which the amplitude occurs is changing
ILLUSTRATION
<B>
ions: *
Ionization occurs when an atom or a molecule acquires a negative or positive charge by gaining or losing electrons often in conjunction with other chemical changes, this electrically charged atom or molecule is called an ion. Ionization can result from the loss of an electron after collisions with subatomic particles, collisions with other atoms, molecules and ions, or through the interaction with electromagnetic radiation. Heterolytic bond cleavage and heterolytic substitution reactions can result in the formation of ion pairs. It can also occur through radioactive decay by the internal conversion process, in which an excited nucleus transfers its energy to one of the inner-shell electrons causing it to be ejected.
SEE ILUSTRATION
<C>
gas-particles (flying & colliding): *
illustration below of gas particles exerting pressure inside a container.
<D>
magnetic fields: *
SEE ILLUSTRATION BELOW:
<E>
electric currents & waves: *
electric current is the continuous flow of the electrons in an electric circuit, the conducting material consists of a large number of free electrons which move from one atom to the other at random.
Electromagnetic waves are waves that can cause charged particles (such as electrons) to move up and down. These waves have both electrical and magnetic properties and can travel through gases, liquids, solids, and through empty space (or a vacuum) at nearly 300,000 kilometers per second (the speed of light). Electromagnetic waves have wavelength & frequency; wavelength is the distance between 2 wave crests (the highest point) or troughs (the lowest point). Frequency (expressed in hertz) refers to the number of wavelengths passing a fixed point in 1 second, the shorter the wavelength, the higher its frequency, the longer the wavelength (eg radio waves) the lower the frequency
the electromagnetic spectrum covers the full range of electromagnetic radiation; ultraviolet radiation has a shorter wavelength than the colour violet, infrared radiation has a wave longer than the colour red. SEE ILLUSTRATION BELOW
<F>
Romanesque ornamentation: *
reliefs.
Man and confronted animals, Cahors Cathedral
Note the block just above, with the abstract shapes
Manuscript illumination, in the elaboration of capital letters and marginal decoration followed the sculptural trend toward linear stylization. Compositions lacked depth & needed flexibility (to be squeezed into the shapes of historiated initials, column capitals & tympanums); the tension between tightly enclosing frames is a recurrent theme; figure sizes reflected varied in size in relation to their importance; landscape backgrounds, when attempted were abstract decorations (not realistic); portraiture did not exist.
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ILLUSTRATION LEFT:
Almost all of the folios of the Book of Kells contain small illuminations like this decorated initial.
ILLUSTRATION RIGHT:
Illuminated Manuscript
The Book of Kells, (folio 292r), circa 800, showing the lavishly decorated text that opens the Gospel of John
ILLUSTRATION LEFT:
Illuminated Manuscript
11th-century Tyniec Sacramentary was written with gold on a purple background.
Metalwork was another area of great artistic expression. Precious objects in metal held high status, more so than paintings. Metalwork, including decoration in enamel, became very sophisticated. Hildesheim Cathedral in Hildesheim, Germany houses a number of outstanding metalwork art
ILLUSTRATION LEFT
The Bronze baptismal font, is a late Romanesque baptismal font dating form 1230, noted for its high quality pictorial decoration for its perfect proportions, considered among the most outstanding works of its type.
The Hezilo chandelier, background, 11th-century Romanesque wheel chandelier; commissioned by Bishop Hezilo of Hildesheim, who rebuilt the cathedral after a fire; he also influenced the program of imagery and inscriptions. It is the largest of four extant wheel chandeliers of the period.
BELOW
detail of Hezilo chandelier
<G>
Gothic architecture up thrust: *
ILLUSTRATION LEFT
Amiens is the tallest completed cathedral in France, reaching an internal height of 138.8 feet. It also has the largest interior volume at 260,000 cubic yards. This is a view of the nave from the west portal looking east towards the alter.
ILLUSTRATION RIGHT
view: upper windows of the nave
<H>
Columbus (longings): *
a sailor from the age of 10; working for Genoese merchants, he travelled to the Aegean, England, Ireland & Iceland & the coast of West Africa. Ambitious, he learned Latin, Portuguese & Castilian, read widely about astronomy, geography & history, including the works of Ptolemy, Pliny's Natural History, Imago Mundi & Marco Polo. He also read Cardinal D'Ailly's Imago Mundi (1410), a work of cosmography, which influenced his estimates of the size of the world. Columbus was familiar with the Greek philosopher Poseidonius, who had calculated the circumference of the earth & with calculations made by the medieval Arabs. Columbus erred however in his estimates, which was 25% smaller than either of these earlier geographers. Based on his estimates he told authorities he could sail from Spain to Japan in 30 days.
ILLUSTRATION BELOW
"Columbus map", 1490, Lisbon, from the workshop of Bartolomeo & Christopher Columbus. It shows the North Atlantic, Europe & Africa; on the far left we see a circular globe
In 1470, the Florentine astronomer Toscanelli suggested to the Portuguese King that sailing west across the Atlantic to reach the Spice Islands, Cathay, & Japan. In 1481, Toscanelli sent Columbus a map implying that a westward route to Asia was possible.
SEE ILLUSTRATION
Toscanelli map
In the 1480s Columbus advanced similar proposals: in 1484, he approached King John II of Portugal but was rejected, Genoa & Venice followed suite. When he approached the Spanish crowns (1486) he claimed his vision was based on readings from the Old Testament. They agreed to sponsor his journey.
SEE main voyages map
Following his 1492 discovery he continued seeking passage to the East Indies making another 3 voyages; he never renounced the belief (in the face of mounting evidence to the contrary) that he had reached the Far East; he named the indigenous peoples "Indians". His quest for Asia may have had religious roots: a millennialist, in his diaries he wrote of gold & imagined it would be used to rebuild Jerusalem & convert all people to Christianity. Late in life he wrote a Book of Prophecies, very apocalyptic in tone.
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<I>
Copernicus (dreams): *
Copernicus went to the University of Bologna in 1496 where he made his first astronomical observations & met the astronomy professor Novara, a man deeply critical of Ptolemy’s astronomical model. He also learned Greek here critical for his studies as major works by Greek astronomers, including Ptolemy, had yet to be translated into Latin. In 1501 he went to Padua to study medicine; in the 16th century medicine included the study of astrology, the motions of the planets & stars. He now began to work on astronomy on his own. He was dissatisfied by Ptolemy’s geocentric model, which failed to follow Aristotle’s requirement for the uniform circular motion of celestial bodies. To get around this problem Ptolemy had introduced his “equant”. Copernicus decided that he could achieve Archimedes’ uniform circular motion by replacing the equant with a different model. Between 1510 & 1514 he wrote an anonymous manuscript, the Commentariolus, outlining his new idea, the heliocentric universe. This short work was circulated to friends & various astronomers but was never printed. It included the basis of his theory but deferred the mathematical demonstrations. He arrived at the heliocentric theory by a careful analysis of planetary models, the only person in the 16th century to do so. By 1532 he had completed his magnum opus, On the Revolutions of the Heavenly Spheres, but resisted publishing, fearing the scorn it would attract on account of its novelty. It was finally published in 1542, the year of his death.
SEE ILLUSTRATION
Copernicus's schematic diagram of his heliocentric theory
of the Solar System from De revolutionibus orbium coelestium
<J>
perspective oil-painting (contemporary with science): *
Linear perspective arose from the desire to make convincing representations of exteriors & interiors, architectural fictions in which to stage narratives. It created more interesting compositions and scaled figures.
see below
Annunciation (predella panel from the St. Lucy Altarpiece)
Domenico Veneziano, 1442–1445, Tempera on panel
The first known picture to make use of linear perspective was created by Brunelleschi (1377-1446) in 1415, depicting the Baptistery in Florence from the front gate of the unfinished cathedral. This, the first mathematical form of linear perspective, projected the illusion of depth onto a 2D plane by use of ‘vanishing points’ to which all lines converged, at eye level, on the horizon. In 1435 Alberti (1404–1472) wrote his De picture (On Painting) which codified the technique. By the mid-1420s paintings fully designed according to the principles of perspective science began to appear.
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​Leon Battista Alberti, Della Pictura drawing showing a horizon line and vanishing point
Masaccio (1401 – 1428), early Renaissance painter, was the first artist to demonstrate full command of the new rules; the figures in his paintings have volume, buildings & landscapes realistically recede into the distance. Masaccio is seen now as being the initiator of the new style of Florentine Realism.
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ILLUSTRATION The Tribute Money, fresco by Masaccio in the Brancacci Chapel (1425-27).
ILLUSTRATION LEFT
Christ Giving the Keys to St. Peter, fresco 1481–1482, Sistine Chapel, Rome.
Perugino (1452-1523) has perfected the system. He uses an architectural backdrop in front of which the action unfolds, his figures reflect diminution by distance & he has perfected the grid system of linear perspective. His cloud-filled sky with the bluish-gray hills in the distance hints at the infinite world that stretches across the horizon.
<K>
instrumental music (contemporary with science): *
Medieval Roots
Medieval music was dominated by voice; until 1100 liturgical music (Gregorian chants, plainsong) dominated; it was monophonic with a single, unaccompanied vocal melody line. Polyphonic (multiple independent vocal melodies) emerged & by the early 14th century came to dominate. The Renaissance (1400 to 1600) saw greater use of instrumentation, as well as the use of the first bass instruments. However instrumental music remained subordinate to voice, much of its repertory was derived from vocal models, for dances & to accompany vocal music. The dominant form of secular vocal music was the madrigal, a poem in Italian with an intense emotional cast, for 4 or 5 voices with no instrumental accompaniment. The low status of instrumental music before 1600 is reflected in the fact that composers did not specify instrumentation; they were added on an ad hoc basis.
the Baroque Age
After 1600 music began to move towards greater instrumentation & away from vocal music; this is reflected in 4 areas: idiomatic writing, texture, instruments & orchestration.
IDIOMATIC WRITING: Renaissance composers never specified which instruments were to play which parts; parts were playable on any instrument with adequate range; composers unconcerned with specific instrumental capabilities. Baroque composers began to specify WHICH instruments were to play & WHICH parts they would play (notably Claudio Monteverdi in his opera scores)
TEXTURE-Renaissance composers used contrapuntal polyphony, all voices being theoretically equal. Baroque composers disliked this counterpoint which obscured the vocal text & promoted monody & treble-bass polarity, with basso continuo; the solo melody & bass line accompaniment the important lines, with the inner voices filling in harmonies. Although initially the concern was for vocal, the principle of a single, clear melody dominating a simple accompaniment carried over to instrumental compositions (after 1601 there was a proliferation of solo instrumental sonatas).
INSTRUMENTS-Renaissance instruments were often limited in pitch range & dynamic scope; few could carry a solo melodic line. Consequently many fell into disuse after 1600. Entire families of Medieval & Renaissance instruments, like the racketts, the low instruments of the woodwind consorts, most of the viol family, the shawm (replaced by the oboe), and the cornett, disappeared. Baroque composers favoured instruments able to carry a melodic line alone, louder & higher, with a variety of dynamics, lending themselves to virtuosic display & emotional expression. The big winner was the violin whose popularity eclipsed both the lute and viola da gamba.
ORCHESTRATION –Prior to the 16th century instruments were grouped together in mixed-instrument or instrument-& voice ensembles, creating a heterogeneous texture. Each member of the ensemble had a distinct part in the texture & played through from beginning to end. In the late 16th century Andrea & Giovanni Gabrieli (at St Mark's Basilica, Venice) began experimenting with placing diverse group of performers, both instrumental & vocal, in antiphonal locations around the vast interior of the church, in what became known as cori spezzati or divided choirs. The choirs were of different size, with radically different combinations of voices & instruments, allowing for dramatic effects, sudden shifts in volume, articulation, timbre & texture. From this came the concertato style, featuring a large ensemble, where smaller groups played successive musical phrases in different styles, or, performed simultaneously in different manners. One phrase might be a solo, the next imitative polyphony, the next homophonic, the next an instrumental tutti & so on.