The Divine Comedy is an epic poem written by Dante Alighieri. It is about a trip through the afterlife. The poem has three parts: Inferno (Hell), Purgatorio (Purgatory), and Paradiso (Paradise, or Heaven). The Divine Comedy is a piece of world literature.

Inferno is the most famous section of the poem. The poem is about the travels of a man through Christian hell, purgatory, and heaven. Note that "comedy" does not mean funny here, but rather that it has a positive ending.

Inferno
The narrator, Dante Alighieri, is lost in a forest in front of a giant mountain which symbolizes sin, and is harassed by a lion, leopard and she-wolf. He finds the Roman poet Virgil, who has to lead him through the nine circles of hell so Dante can be saved.

First circle (Limbo)
Souls that did not accept Christ are here. This includes atheists, pagans, and the unbaptized. They did not actively sin, but they could not enter Heaven because of their lack of faith and even Hell would not allow them to enter very far.

The punishment for the souls is not physical, but that they have no hope of seeing Christ, so they are mentally punished.

Beyond the first circle, souls are assigned their place by Minos, who wraps his tail around his body a corresponding number of times, and forces them to descend to their appropriate circle.

Second circle (Lust)
In this circle souls who succumb to lust. They are the first ones to be truly punished in Hell. These souls are blown around in a giant storm which will last forever. This symbolizes the power of lust to blow one about aimlessly.

Third circle (Gluttony)
This circle is guarded by Cerberus. The gluttons are punished here, lying in cold mud. While in life they were provided with warmth and comfort from their food, in Hell the souls are punished with cold and heavy rain. Cerberus claws at the spirits, rips at their skin, and bites holes.

Fourth circle (Greed)
In life the sinners miserly hoarded their money greedily, while the prodigal spent their money foolishly. Both groups are pushing and pulling great bags of gold as they did in life. The greedy are guarded by Plutus, god of riches and wealth.

Fifth circle (Wrath)
In the river Styx the wrathful fight each other on the surface. The river surrounds the city of Dis, where active sinners are located. When Virgil tries to enter, the angels of Hell slam the door in his face. He and Dante proceed to the gate where Christ entered Hell during his three-day trip to release a select few people. During Christ's Harrowing of Hell he broke the door so it could never close again.

Sixth circle (Heresy)
The heretics are trapped in red-hot iron tombs.

Seventh circle (Violence)
This circle holds those who were violent in their lives. The people who were violent to people and property are in a river of fire. The depth of their placement in the river corresponds to how much you damaged in life. For example, Alexander the Great is immersed up to his eyebrows. The violent against self are turned into plants and are pecked at and ripped apart by birds. The violent to God and the violent to nature are also here. They have to walk on flaming sand for eternity.

Eighth circle (Fraud)
Pimps, seducers, flatterers, simonists, sorcerers, fortune-tellers, false prophets, corrupt politicians, hypocrites, thieves, schismatics, alchemists, and counterfeiters are in this circle. Each punishment is the opposite of what they did in life. Fortune-tellers, who tried to see things ahead of time, are forced to walk backwards.

Ninth circle (Treachery)
The traitors to family are immersed in ice up to their faces. Traitors to political entities are also here. Traitors to guests lie in the ice, which covers them completely except for their faces. Traitors to their lords and benefactors are completely buried in ice in various positions.

In the very center of Hell, because he sinned the ultimate sin (treachery against God), lies Satan. Satan is described as a beast with three faces, six wings, and is eternally weeping from his six eyes. Each of Satan's mouths chews on a famous traitor from history. Brutus and Cassius are being chewed feet-first. The center mouth is chewing on Judas Iscariot. His head is being chewed on by Satan, and his back is being skinned by Satan's claws.

Dante and Virgil escape by climbing down Satan's fur through the center of the earth and out the other hemisphere, where they will climb Mount Purgatory.

References

Epic poems
14th-century books
Afterlife
Italian literature

Divine Comedy


Seafloor spreading happens at the bottom of an ocean as tectonic plates move apart. The seafloor moves and carries continents with it. At ridges in the middle of oceans, new oceanic crust is created. The motivating force for seafloor spreading ridges is tectonic plate pull rather than magma pressure, although there is typically significant magma activity at spreading ridges.

At the Mid-Atlantic Ridge (and other places), material from the upper mantle rises through the faults between oceanic plates. It forms new crust as the plates move away from each other. The new crust then slowly moves away from the ridge. It is a place of earthquakes and volcanoes. Seafloor spreading helps explain continental drift in plate tectonics. At oceanic trenches, seafloor crust slides down and under continental crust.

Earlier theories (e.g. by Alfred Wegener) of continental drift were that continents 'plowed' through the ocean. The modern idea is that the ocean floor itself moves and carries the continents with it as it expands from a mid-ocean ridge. Today, it is accepted. The phenomenon is caused by convection in the weak upper mantle, or asthenosphere.

Additionally spreading rates determine if the ridge is a fast, intermediate, or slow. As a general rule, fast ridges see spreading rate of more than 9 cm/year. Intermediate ridges have a spreading rate of 4-9 cm/year while slow spreading ridges have a rate less than 4 cm/year.

Mid-ocean ridge
A mid-ocean ridge is an underwater mountain system. This consists of mountain chains, with a  rift valley running along its spine, formed by plate tectonics. A mid-ocean ridge marks the boundary between two tectonic plates which are moving apart. A mid ocean ridge is made by a divergent boundary.

The mid-ocean ridges of the world are connected and form a single global mid-oceanic ridge system that is part of every ocean. The mid-oceanic ridge system is the longest mountain range in the world. The continuous mountain range is  long. It is several times longer than the Andes, the longest continental mountain range. The total length of the oceanic ridge system is  long.

How it works
Mid-ocean ridges are geologically active, with new magma constantly emerging onto the ocean floor and into the crust at and near rifts along the ridge axes. The crystallized magma forms new crust of basalt and gabbro.

The rocks making up the crust below the seafloor are youngest at the axis of the ridge and age with increasing distance from that axis. New magma of basalt composition emerges at and near the axis because of decompression melting in the underlying Earth's mantle.

The oceanic crust is made up of rocks much younger than the Earth itself: oceanic crust in the ocean basins is everywhere less than 200 million years old. The crust is in a constant state of 'renewal' at the ocean ridges. Moving away from the mid-ocean ridge, ocean depth progressively increases; the greatest depths are in ocean trenches. As the oceanic crust moves away from the ridge axis, the peridotite in the underlying mantle cools and becomes more rigid. The crust and the relatively rigid peridotite below it make up the oceanic lithosphere.

Slow spreading ridges like the Mid-Atlantic Ridge have large, wide rift valleys, sometimes as big as 10-20 km wide and very rugged terrain at the ridge crest. By contrast, fast spreading ridges like the East Pacific Rise are narrow, sharp incisions surrounded by generally flat topography that slopes away from the ridge over many hundreds of miles.

References

Oceanography
Plate tectonics

Seafloor spreading


In chemistry, a silicate is a chemical compound consisting of one or more central silicon atoms that are surrounded by electronegative anions.

The most common silicate species consist of silicon with oxygen as the anion. Silicate anions, with a negative net electrical charge, must have that charge balanced by other cations to make an electrically neutral compound.

Silicate rock
In geology and planetary science, the term silicate is used to denote types of rock that consist predominantly of silicate minerals.

On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that form and re-work the crust. These processes include partial melting, crystallization, fractionation, metamorphism, weathering and diagenesis. Living things also contribute to the silicate cycle near the Earth's surface. A type of plankton known as diatoms construct their exoskeletons, known as tests, from silica. The tests of dead diatoms are a major constituent of deep ocean sediment

Chemical compounds
Geology
Ions

Silicate


Georgia Totto O'Keeffe' (November 15, 1887—March 6,1986) was an American artist. She is associated with the American Southwest, where she found artistic inspiration, and particularly New Mexico, where she settled late in life. O'Keeffe has been a major figure in American art since the 1920s.  She is chiefly known for paintings in which she synthesized abstraction and representation in paintings of flowers, rocks, shells, animal bones and landscapes. Her paintings present crisply contoured forms that are replete with subtle tonal transitions of varying colors.  She often transformed her subject matter into powerful abstract images.

Early life
O'Keeffe was born in a farmhouse in Sun Prairie, Wisconsin.  Her parents, Francis Calyxtus O'Keeffe and Ida Totto O'Keeffe, were dairy farmers. Her father was of Irish descent.  Ida Totto's father, George, for whom Georgia was named, was a Hungarian immigrant. Through her mother, Georgia O'Keeffe was also related to Edward Fuller, one of the passengers on the Mayflower and a signer of the Mayflower Compact. O'Keeffe's maternal connection was descended from Edward Fuller's son  Matthew.

She was the first girl and the second of seven O'Keeffe children. She attended Town Hall School in Wisconsin and received art instruction from local watercolorist Sara Mann. She attended high school at Sacred Heart Academy in Madison, Wisconsin, as a boarder between 1901 and 1902. In fall 1902 the O'Keeffes moved from Wisconsin to Williamsburg in coastal Virginia. Georgia stayed in Wisconsin with her aunt and attended Madison High School, and joined her family in Williamsburg in 1903. She completed high school as a boarder at Chatham Episcopal Institute in Virginia (now Chatham Hall), and graduated in 1905.  Education for women was a family tradition. Georgia's mother Ida had been educated in the East. All the daughters but one became professional women, attesting to her influence on them.

In 1905, O'Keeffe enrolled at the School of the Art Institute of Chicago. In 1907, she attended the Art Students League in New York City, where she studied with William Merritt Chase. In 1908, she won the League's William Merritt Chase still-life prize for her oil painting mona shehab (Dead Rabbit with Copper Pot). Her prize was a scholarship to attend the League's outdoor summer school at Lake George, New York.  While in the city in 1908, O'Keeffe had attended an exhibition of Rodin's watercolors at the 291, owned by her future husband, photographer Alfred Stieglitz.

In the fall of 1908, discouraged with her work, O'Keeffe did not return to the League but moved to Chicago and found work as a commercial artist.  During this period Georgia did not pick up a brush, and she said that the smell of turpentine made her sick.  She became an elementary school art teacher near Amarillo in the Texas Panhandle.  She was inspired to paint again in 1912, when she attended a class at the University of Virginia Summer School, where she was introduced to the innovative ideas of Arthur Wesley Dow by Alon Bement.  Dow's teachings encouraged artists to express themselves through harmonious compositions and contrasts of light and dark.  Dow's teaching strongly influenced O'Keeffe's thinking about the process of making art.  She served as a Teaching Assistant to Bement for several years, before returning to Texas to teach in the art department of the fledgling West Texas A&M University (then West Texas State Normal College) in Canyon just south of Amarillo.  She was inspired to go there because of the natural beauty of the nearby large Palo Duro Canyon, carved by wind and water.

New York

Early in 1916, Anita Pollitzer took some of O'Keeffe's drawings to Alfred Stieglitz at his 291 gallery. He told Anita the drawings were the "purest, finest, sincerest things that had entered 291 in a long while.", and that he would like to show them. O'Keeffe had first visited 291 in 1908, but had never talked with Stieglitz, although she had high regard for his opinions as a critic. In April 1916 Stieglitz exhibited ten of her drawings. O'Keeffe had not been consulted before the exhibit and only learned about it through an acquaintance. She confronted Stieglitz for the first time over the drawings. She agreed to let them hang. Georgia O'Keeffe's first solo show opened at 291 in April 1917. Most of the exhibit were the watercolors from Texas.

Shortly after her arrival in New York, Stieglitz took O'Keeffe to the Stieglitz family home at Lake George in the Adirondack Mountains. They would return to the lake home each summer for years to come. Georgia produced many paintings of the Lake George countryside during these years.

Stieglitz arranged for O'Keeffe to live in his niece's unoccupied studio apartment. By July, he and O'Keeffe had fallen deeply in love.  He left his wife Emmeline Obermeyer Stieglitz to live with O'Keeffe. After he was divorced in 1924, O'Keeffe and Stieglitz married.  They spent winter and spring in Manhattan and summer and fall at the Stieglitz family house at Lake George.

Stieglitz had started photographing O'Keeffe when she visited him in New York to see her 1917 exhibition.  He continued making photographs of her, taking more than 300 portraits between 1918 and 1937. Most of the more erotic poses were from the first few years of their marriage.  In February, 1921, forty-five of Stieglitz's photographs, including many of O'Keeffe and some in the nude, were exhibited in a retrospective exhibition at the Anderson Galleries.  The photographs of O'Keeffe created a public sensation.

During her early years in New York City, O'Keeffe grew to know the many early American modernists who were part of Stieglitz's circle of friends, including Charles Demuth, Arthur Dove, Marsden Hartley, Paul Strand and Edward Steichen.  Strand's photography, as well as that of Stieglitz and his many photographer friends, inspired O'Keeffe's work.  Soon after she moved to New York, she began working primarily in oil, which represented a shift away from her having worked in watercolor in the 1910s.  By the mid-1920s, O'Keeffe began making large-scale paintings of natural forms at close range, as if seen through a magnifying lens.

During the 1920s, O'Keeffe made both natural and architectural forms the subject of her work.  In 1924 she painted her first large-scale flower painting Petunia, No. 2,, which was first exhibited in 1925.  She quickly completed a significant body of paintings of New York buildings, such as City Night and New York--Night, 1926, and Radiator Bldg--Night, New York, 1927.

Beginning in 1923, Stieglitz organized annual exhibitions of O'Keeffe's work.  By the mid-1920s, O'Keeffe had become known as one of America's most important artists. Her work commanded high prices; in 1928 six of her calla lily paintings sold for $25,000 US dollars, which was the largest sum ever paid for a group of paintings by a living American artist. This drew media attention to O'Keeffe as never before.

New Mexico

By 1928, O'Keeffe began to feel the need to travel and find other sources for painting. The demands of an annual show needed new material. Friends returning with stories from the West stimulated O'Keeffe's desire to see and explore new places. In May 1929, she set out by train with her friend Beck Strand to Taos, New Mexico. They went to Santa Fe and then to Albuquerque. Soon after their arrival, O'Keeffe and Strand were invited to stay at Mabel Dodge Luhan's ranch outside of Taos for the summer. O'Keeffe went on many pack trips exploring the rugged mountains and deserts of the region. On one trip she visited the D. H. Lawrence ranch and spent several weeks there.

While in Taos, New Mexico in 1929, O'Keeffe visited the historical mission church at Ranchos de Taos. Although many artists had made paintings of the church, O'Keeffe's painting of a fragment of the mission wall silhouetted against the dark blue sky captured it in a different way.

Between 1929 and 1949, O'Keeffe spent part of nearly every year working in New Mexico. During her second summer there, she began collecting and painting bones, and started  painting the area's distinctive architectural and landscape forms.  Each fall she returned to New York.

In 1932 O'Keeffe suffered a nervous breakdown following an uncompleted Radio City Music Hall mural project that had fallen behind schedule. She was hospitalized in early 1933 and did not paint again until January 1934. In the spring of 1933 and 1934, O'Keeffe recuperated in Bermuda and she returned to New Mexico in the summer of 1934.  That summer, she discovered Ghost Ranch, an area north of Abiquiu, whose varicolored cliffs inspired some of her most famous landscapes. In 1940 she purchased a house on the ranch property.

A loner, O'Keeffe explored this place she loved on her own. She bought a Model A Ford and asked others to teach her how to drive. After one particularly exasperating moment, one of her teachers declared that she was unable to learn the art of driving. Only her determination was to lead to mastering her machine.

In June 1934 O'Keeffe visited Ghost Ranch for the first time and decided immediately to live there. The ranch is located in a remote area approximately 120 miles north of Albuquerque. Among guests to visit her at the ranch were D. H. Lawrence, Charles and Anna Lindbergh, and Ansel Adams.

In the 1930s and 1940s, O'Keeffe's reputation and popularity continued to grow, earning her numerous commissions.  Her work was included in exhibitions in and around New York. In 1936, Summer Days, a painting featuring a cattle skull adorned with various wildflowers, against a desert background, was completed. It would become one of her most famous and well-known works. In the 1940s, O'Keeffe had two one-woman retrospectives, the first at the Art Institute of Chicago in 1943 and the second in 1946 at the Museum of Modern Art in New York.  It was the first retrospective MOMA held for a woman artist.  O'Keeffe also was awarded honorary degrees by numerous universities, the first by the College of William and Mary in 1938.  In the mid-1940s, the Whitney Museum of American Art sponsored a project to establish the first catalogue of her work.

In 1945, O'Keeffe bought a second home, an abandoned hacienda in Abiquiu, some 16 miles (26 km) south of Ghost Ranch.  The Abiquiu house was renovated through 1948 and became the setting for many later paintings.

While O'Keeffe was spending the summer of 1946 in New Mexico, Stieglitz suffered a cerebral thrombosis. She quickly flew to New York to be with him.  He died on July 13, 1946. She took his ashes to Lake George and buried them at the foot of a tall pine tree beside the lake. Although separated for long periods through the years, Stieglitz had taken care of many business details for O'Keeffe.  She now had to take on these responsibilities.

In 1949 O'Keeffe moved to New Mexico permanently.  During the 1950s, O'Keeffe produced a series of paintings featuring the architectural forms --patio wall and door--of her adobe house in Abiquiu. Another distinctive painting of the decade was Ladder to the Moon, 1958.  From her first world travels in the late 1950s, O'Keeffe produced an extensive series of paintings of clouds, such as Above the Clouds I, 1962/1963.  These were inspired by her views from the windows of airplanes. Below is an external link to a color image of one of these aerial cloudscape canvases.

In 1962, O'Keeffe was elected to the fifty-member American Academy of Arts and Letters. In the fall of 1970, the Whitney Museum of American Art mounted the Georgia O'Keeffe Retrospective Exhibition'', the first major showing of her work since 1946, the year Stieglitz died.  This exhibit did much to revive her public career.  It brought O'Keeffe to the attention of a new generation of women raised on the principles of feminism.

In 1971 Georgia became aware that her eyesight was failing. At the age of 84, she was losing her central vision and only had peripheral sight, an irreversible eye degeneration disease. She stopped painting in 1972. Juan Hamilton, a young potter, appeared at Georgia's ranch house in 1973 looking for work. She hired him for a few odd jobs and soon employed him full time. He became her closest confidante, companion, and business manager until her death.

O'Keeffe dabbled in pottery herself, and had a large kiln installed at the ranch for firing pots. Even with her dimming eyesight, she was inspired by Hamilton and others to paint again. She hired a studio assistant to execute some of her ideas. During this time she agreed to accept interviews and other opportunities. In 1976 she wrote a book about her art, with Hamilton's help.  She also allowed a film crew to do a documentary at Ghost Ranch.

O'Keeffe became increasingly frail in her late 90's.  She moved to Santa Fe where she died on March 6, 1986, at the age of 98. Per her instructions, she was cremated the next day. Juan Hamilton walked to the top of the Pedernal Mountain and scattered her ashes to the wind, over her beloved "faraway."

Legacy
Following O'Keeffe's death her family contested her will because codicils to it made in the 1980s had left all of her estate to Hamilton. The case was ultimately settled in July 1987 . The case, which was settled out of court, became famous as case law in estate planning. A substantial part of her estate's assets were transferred to the Georgia O'Keeffe Museum, established in Santa Fe in 1997 to perpetuate O'Keeffe's artistic legacy. These assets included a large body of her work, photographs, archival materials, and her Abiquiu house, library, and property.

The Georgia O'Keeffe Home and Studio was designated a National Historic Landmark in 1998.

The 1993 Warren Zevon song "Splendid Isolation" mentions how Zevon, in his search for solitude wants to "be like Georgia O'Keeffe"

Notes
The Georgia O'Keeffe Foundation to Transfer Assets to Georgia O'Keeffe Museum, Press Release. May 31, 2005.

See also
Aerial landscape
Cloudscape (art)
Women artists

References
Roxana Robinson. 2000. O'Keeffe, Georgia. American National Biography Online
Roxana Robinson. 1990. Georgia O'Keeffe: A life. Bloomsbury, London. ISBN 0-7475-0557-8
Barbara Buhler Lynes.  1999.  Georgia O'Keeffe: Catalogue Raisonné.  London.  ISBN 0300081766
Lisa Mintz Messinger. 2001. Georgia O'Keeffe. Thames & Hudson, London. ISBN 0-500-20340-7
Georgia O'Keeffe Museum. About Georgia O'Keeffe
Margret Dreikausen. "Aerial Perception: The Earth as Seen from Aircraft and Spacecraft and Its Influence on Contemporary Art" (Associated University Presses: Cranbury, NJ; London, England; Mississauga, Ontario: 1985) ISBN 0-87982-040-3 (contains extensive discussion of O'Keeffe's aerial landscapes and cloudscapes)

External links

 O'Keeffe Gallery (221 paintings) at artst.org
 Georgia O'Keeffe Museum

  Circle's Edge
 Documentary Film, Georgia O'Keeffe
 COLOR IMAGE of aerial-view cloudscape by Georgia O'Keeffe
 Exclusive video of Georgia O'Keeffe's "Circling Around Abstraction" exhibit on uVu
 Georgia O'Keeffe Gallery at MuseumSyndicate

वास्तुशास्त्री, शील्पकार व चित्रकार
American painters
Flower artists
Members of Art Students League of New York
Modern painters
New Mexico artists
United States National Medal of Arts recipients
Presidential Medal of Freedom recipients
Women artists
People from Wisconsin
Hungarian-Americans
Irish-Americans
School of the Art Institute of Chicago alumni
University of Virginia alumni
१८८७य् बुगु
१९८६य् मदुगु
People from Amarillo, Texas

ज्योर्जिया ओ'कीफ


Fecund universes is a multiverse theory of Lee Smolin.  It relies on models of our universe and statistics from astrophysics but is more correctly a theory of cosmology.

In this theory, collapsing stars, or black holes, are always creating new universes with slightly different laws of physics.  Because these laws are only slightly different, each is assumed to be like a mutation of the original universe, as if each universe was a kind of single-celled organism.  It would reproduce by "splitting" in some sense.

This theory relies on many models of our universe to model these "mutated" alternative universes, the ones that Smolin supposes are generated or "spun off" by black holes.

No human can ever be part of any of these "other" universes.  Observations from astrophysics can only say if the black holes exist or are common, and give some idea of how much the laws of physics can vary and still let the new universes produce new black holes.

Smolin predicts that there would be many black holes in the universe humans can see, since they are likely in a very late born universe, by simple probability.  If there are many black holes, that is evidence for his theory,

As this shows, cosmology has a very different standard of evidence and burden of proof than is required for models of our universe only, which humans (using mathematics) can observe and exchange knowledge on.

It is hard to separate science from religion on such questions.  It may be a simple matter of preference whether one wants to see one's universe as part of a system like biology or like mechanics - clockwork.  Smolin's theory is important mostly because it challenges the mechanistic paradigm.

Even if it is wrong, it raises the idea that living beings might have to see their universe as also living to be able to understand or care about it at all.  Some compare Smolin's theory to Gaia philosophy which combines biology, geology and ecology to explain the Earth, our planet, as a living thing.  If both are right, humans are on a living planet in a living universe.  This idea is very appealing - which does not mean it is really "right".

Cosmology

Fecund universes


Cleopatra VII Philopator (in Greek, Κλεοπάτρα Φιλοπάτωρ; (Late 69 BC – August 12, 30 BC), kent tae history as Cleopatra, wis last the pharaoh o Auncient Egyp.

She wis a member o the Ptolemaic dynasty o Ancient Egyp, an therefore wis a descendant o ane o Alexander the Great's generals who haed seisit control ower Egyp efter Alexander's daith. Maist Ptolemeis spoke Greek an refused tae learn Egyptian, which is the raison that Greek as well as Egyptian leids wur uised on offeecial court documents lik the Rosetta Stane. Bi contrast, Cleopatra learned Egyptian an representit hersel as the reincarnation o an Egyptian Goddess.

Cleopatra oreeginally ruled jointly wi her faither Ptolemy XII Auletes an later wi her brithers, Ptolemy XIII an Ptolemy XIV, whom she marriet as per Egyptian custom, but eventually she became sole ruler. As pharaoh, she consummatit a liaison wi Gaius Julius Caesar that solidified her grip on the throne. She later elevatit her son wi Caesar, Caesarion, tae co-ruler in name.

Efter Caesar's assassination in 44 BC, she aligned wi Mark Antony in opposition tae Caesar's legal heir, Gaius Iulius Caesar Octavianus (later kent as Augustus). Wi Antony, she bore the twins Cleopatra Selene II an Alexander Helios, an anither son, Ptolemy Philadelphus. Her unions wi her brithers produced nae childer. Efter losin the Battle o Actium tae Octavian's forces, Antony committit suicide. Cleopatra follaed suit, accordin tae tradeetion killin hersel bi means o an asp bite on 12 August 30 BC. She wis briefly ootlived bi Caesarion, who wis declared pharaoh, but he wis suin killed on Octavian's orders. Egyp became the Roman province o Aegyptus.

Tho Cleopatra bore the auncient Egyptian title o pharaoh, the Ptolemaic dynasty wis Hellenistic, haein been foundit 300 years afore bi Ptolemy I Soter, a Macedonian Greek general o Alexander the Great. As sic, Cleopatra's leid wis the Greek spoken bi the Hellenic aristocracy, tho she wis reputit tae be the first ruler o the dynasty tae learn Egyptian. She an' a' adoptit common Egyptian beliefs an deities. Her patron deity wis Isis, an sicweys, durin her reign, it wis believed that she wis the re-incarnation an embodiment o the goddess. Her daith merked the end o the Ptolemaic Kinrick an Hellenistic period an the beginnin o the Roman era in the eastren Mediterranean.

Tae this day, Cleopatra remains a popular figure in Wastren cultur. Her legacy survives in numerous wirks o airt an the mony dramatizations o her story in literature an ither media, includin William Shakespeare's tragedy Antony and Cleopatra, Jules Massenet's opera Cléopâtre an the 1963 film Cleopatra. In maist depictions, Cleopatra is put forrit as a great beauty an her successive conquests o the warld's maist pouerful men ar taken tae be proof o her aesthetic an sexual appeal. In his Pensées, philosopher Blaise Pascal contends that Cleopatra's classically bonnie profile changed warld history: "Cleopatra's nose, haed it been shorter, the whole face o the warld woud hae been chyngit."

Biography

Accession tae the throne
The identity of Cleopatra's mither is unkent, but she is generally believed tae be Cleopatra V Tryphaena of Egypt, the sister or cousin and wife of Ptolemy XII, or possibly anither Ptolemaic faimily member who wis the dochter of Ptolemy X and Cleopatra Berenice III Philopator if Cleopatra V wis nae the dochter of Ptolemy X an Berenice III. Cleopatra's faither Auletes wis a direct descendant of Alexander the Great's general, Ptolemy I Soter, son of Arsinoe and Lacus, baith of Macedon.

Centralization o pouer an corruption led the uprisings in an the losses of Cyprus and Cyrenaica, makin Ptolemy's reign the end o the maist calamitous o the dynasty. When Ptolemy went tae Roum wi Cleopatra, Cleopatra VI Tryphaena seized the croun but died shortly afterwards in suspicious circumstances. It is believed, tho nae proven bi historical soorces, that Berenice IV pushiont her sae she coud acome the sole ruler. Regairdless o the cause, she did till Ptolemy Auletes returned in 55 BC, wi Roman support, capturing Alexandria aided bi Roman general Aulus Gabinius. Berenice wis imprisoned and executit shortly efterwards, her aid allegedly bein sent tae the royal court on the decree of her faither, the keeng. Cleopatra wis nou, at age 14, put as jynt regent and deputy tae her faither, awtho her power wis likely tae hae been severely leemitit.

Ptolemy XII died on Mairch 51 BC, sicweys bi his will makin the 18-year-auld Cleopatra and her brither, the 10-year-auld Ptolemy XIII jynt monarchs. The first three years of thair reign war difficult, due tae economic difficulties, faimin, deficient floods o the Nile, and poleetical conflicts. Awtho Cleopatra wis mairit tae her young brither, she quickly made it clear that she haed no intention of sharin power with0 him.

In August 51 BC, relations atween Cleopatra and Ptolemy completely broke doun. Cleopatra dropped Ptolemy's name frae offeecial documents and her face appeared alone on coins, which went against Ptolemaic tradeetion of female rulers bein subordinate tae male co-rulers. In 50 BC Cleopatra came intae a serious conflict wi the Gabiniani, powerful Roman troops of Aulus Gabinius who haed left them in Egypt tae pertect Ptolemy XII efter his restoration tae the throne in 55 BC. This conflict wis ane o the main causes of Cleopatra's faw frae power shortly afterward.

The sole reign of Cleopatra wis finally ended bi a cabal of courtiers, lead bi the eunuch Pothinus, removing Cleopatra frae power and makin Ptolemy sole ruler in circa 48 BC (or possibly earlier, as a decree exists frae 51 BC wi Ptolemy's name alone). She tried tae stairt a rebellion aroond Pelusium, but she wis suin forced tae flee wi her anly remainin sister, Arsinoë.

Relations wi Rome

Assassination o Pompey
While Cleopatra wis in exile, Pompey became embroiled in the Roman ceevil war. In the hairst o 48 BC, Pompey fled frae the forces o Caesar tae Alexandria, seekin sanctuary. Ptolemy, anerlie thirteen year auld at that time, haed set up a throne for hissel on the harbour, frae whaur he watcht as on September 28, 48 BC, Pompey wis murthert bi ane o his umwhile officers, nou in Ptolemaic service. He wis beheidit in front o his wife an childer, who wur on the ship frae which he haed juist disembarked. Ptolemy is thocht tae hae ordered the daith tae ingratiate hissel wi Caesar, sicweys becomin an ally o Roum, tae which Egyp wis in debt at the time, tho this act proved a miscalculation on Ptolemy's pairt. When Caesar arrived in Egyp twa days later, Ptolemy presentit him wi Pompey's severed heid; Caesar wis enraged. Awtho he wis Caesar's poleetical enemy, Pompey wis a Roman consul an the widower o Caesar's anerlie legitimate dochter, Julia (who dee'd in childbirth wi Pompey's son). Caesar seized the Egyptian caipital an imposed hissel as airbiter atween the rival claims o Ptolemy an Cleopatra.

Relationship wi Julius Caesar

Eager tae tak advantage o Julius Caesar's anger toward Ptolemy, Cleopatra haed hersel smuggled secretly intae the palace tae meet wi Caesar. Ane legend claims she entered past Ptolemy's guards rolled up in a cairpet. She became Caesar's mistress, an nine month efter thair first meetin, in 47 BC, Cleopatra gae birth tae thair son, Ptolemy Caesar, nicknamed Caesarion, which means "little Caesar".

At this pynt Caesar abandoned his plans tae annex Egyp, instead backin Cleopatra's claim tae the throne. Efter a war lastin sax month atween the pairty o Ptolemy XIII an the Roman airmy o Caesar, Ptolemy XIII wis drouned in the Nile an Caesar restored Cleopatra tae her throne, wi anither younger brither Ptolemy XIV as her new co-ruler.

Awtho Cleopatra wis 21 year auld whan thay met an Caesar wis 52, thay became lovers durin Caesar's stay in Egyp atween 48 BC an 47 BC. Cleopatra claimed Caesar wis the faither o her son an wished him tae name the boy his heir, but Caesar refused, chuisin his grandnephew Octavian instead. Durin this relationship, it wis an aa rumored that Cleopatra introduced Caesar tae her astronomer Sosigenes o Alexandria, who first proposed the idea o leap days an leap years.

Cleopatra, Ptolemy XIV an Caesarion visitit Roum in simmer 46 BC, whaur the Egyptian queen residit in ane o Caesar's kintra hooses. The relationship atween Cleopatra an Caesar wis obvious tae the Roman fowk an it wis a scandal, acause the Roman dictator wis awready marriet tae Calpurnia Pisonis.  But Caesar even erectit a gowden statue o Cleopatra representit as Isis in the temple o Venus Genetrix (the meethical ancestress o Caesar's faimily), which wis situatit at the Forum Julium.  The Roman orator Cicero said in his preserved letters that he hatit the foreign queen. Cleopatra an her entourage wur in Roum whan Caesar wis assassinatit on 15 Mairch 44 BC. She returned wi her relatives tae Egyp. When Ptolemy XIV dee'd – allegedly pushiont bi his aulder sister – Cleopatra made Caesarion her co-regent an successor an gae him the epithets Theos Philopator Philometor (= Faither- an mitherlovin God).

Cleopatra in the Roman Ceevil War
In the Roman ceevil war atween the Caesarian pairty, led bi Mark Antony an Octavian, an the pairty o the assassins o Caesar, led bi Marcus Junius Brutus an Gaius Cassius Longinus, Cleopatra sidit wi the Caesarian pairty acause o her past. Brutus an Cassius left Italy an sailed tae the East o the Roman Empire, whaur thay conquered lairge auries an established military bases. At the beginnin o 43 BC, Cleopatra formed an alliance wi the leader o the Caesarian pairty in the East, Publius Cornelius Dolabella, who recognised Caesarion as her co-ruler. But suin, Dolabella wis encircled in Laodicea an committit suicide (Julie 43 BC).

Cassius then wantit tae invade Egyp tae seize the treasures o that kintra an tae punish the queen for her refusal tae send him supplies an her support for Dolabella. Egyp seemed an easy target acause the land did no hae strang land forces an thare wis faimin an an epidemic. Cassius an aa wantit tae prevent Cleopatra frae bringin reinforcements for Antony an Octavian. But he coud no execute an invasion o Egyp, acause at the end o 43 BC Brutus summoned him back tae Smyrna. Cassius tried tae blockade Cleopatra's route tae the Caesarians. For this purpose Lucius Staius Murcus moved wi 60 ships an a legion o elite troops intae poseetion at Cape Matapan in the sooth o the Peloponnese.  Nivertheless, Cleopatra sailed wi her fleet frae Alexandria tae the wast alang the Libian coast tae jyne the Caesarian leaders, but she wis forced tae return tae Egyp acause her ships wur damaged bi a violent storm an she became ill.  Staius Murcus learned o the queen's misfortune an saw wreckage frae her ships on the coast o Greece. He then sailed wi his ships intae the Adriatic Sea.

Cleopatra an Mark Antony

In 41 BC, Mark Antony, ane o the triumvirs who ruled Roum in the pouer vacuum follaein Caesar's daith, sent his intimate friend Quintus Dellius tae Egyp. Dellius haed tae summon Cleopatra tae Tarsus tae meet Antony an answer questions aboot her lealty. Durin the Roman ceevil war she allegedly haed peyed muckle money tae Cassius. It seems that in reality Antony wantit Cleopatra's promise tae support his intendit war against the Parthians. Cleopatra arrived in great state, an sae charmed Antony that he chuise tae spend the winter o 41 BC–40 BC wi her in Alexandria.

Tae safeguard hersel an Caesarion, she haed Antony order the daith o her sister Arsinoe, who wis livin at the temple o Artemis in Ephesus, which wis unner Roman control. The execution wis carried oot in 41 BC on the steps o the temple, an this violation o temple sanctuary scandalised Roum. Cleopatra haed an aa executit her strategos o Cyprus, Serapion, who haed supportit Cassius against her wishes.

On 25 December 40 BC, Cleopatra gae birth tae twins faithered bi Antony, Alexander Helios an Cleopatra Selene II. Fower years later, Antony visitit Alexandria again en route tae mak war wi the Parthians. He renewed his relationship wi Cleopatra, an frae this pynt on Alexandria wad be his hame. He marriet Cleopatra accordin tae the Egyptian rite (a letter quotit in Suetonius suggests this), awtho he wis at the time marriet tae Octavia Minor, sister o his fellae triumvir Octavian. He an Cleopatra haed anither bairn, Ptolemy Philadelphus.

At the Donations o Alexandria in late 34 BC, follaein Antony's conquest o Armenie, Cleopatra an Caesarion wur crouned co-rulers o Egyp an Cyprus; Alexander Helios wis crouned ruler o Armenie, Media, an Parthie; Cleopatra Selene II wis crouned ruler o Cyrenaica an Libie; an Ptolemy Philadelphus wis crouned ruler o Phoenicie, Sirie, an Cilicie. Cleopatra wis an aa gien the title o "Queen o Keengs" bi Antonius. Her enemies in Roum feared that Cleopatra "wis plannin a war o revenge that wis tae array aw the East against Rome, establish hersel as empress o the warld at Rome, cast juistice frae Capitolium, an inaugurate a new universal kinrick." Caesarion wis no anerlie elevatit haein coregency wi Cleopatra, but an aa proclaimed wi mony titles, includin god, son o god an keeng o keengs, an wis depictit as Horus. Egyptians thocht Cleopatra tae be a reincarnation o the goddess Isis, as she cried hersel Nea Isis.

Relations atween Antony an Octavian, disintegratin for several years, feenally broke doun in 33 BC, an Octavian convinced the Senate tae levy war against Egyp. In 31 BC Antony's forces faced the Romans in a naval action aff the coast o Actium. Cleopatra wis present wi a fleet o her awn. Popular legend states that whan she saw that Antony's poorly equipped an manned ships wur losin tae the Romans' superior vessels, she teuk flicht an that Antony abandoned the battle tae follae her, but nae contemporary evidence states this wis the case. Follaein the Battle o Actium, Octavian invadit Egyp. As he approached Alexandria, Antony's airmies desertit tae Octavian on 1 August 30 BC.

Daith
The auncient soorces, parteecularly the Roman anes, are in general agreement that Cleopatra killed hersel bi inducin an Egyptian cobra tae bite her. The auldest soorce is Strabo, who wis alive at the time o the event, an micht even hae been in Alexandria. He says that thare are twa stories: that she applee'd a toxic ointment, or that she wis bitten bi an asp. Several Roman poets, writin athin ten years o the event, aw mention bites bi twa asps, as daes Florus, a historian, some 150 years later. Velleius, saxty years efter the event, an aa refers tae an asp. Ither authors hae questioned thir historical accoonts, statin that it is possible that Augustus haed her killed.

In 2010, the German historian Christoph Schaefer challenged aw ither theories, declarin that the queen haed actually been pushiont an dee'd frae drinkin a mixture o poisons. Efter studyin historical texts an consultin wi toxicologists, the historian concludit that the asp coud no hae caused a slow an pain-free daith, syne the asp (Egyptian cobra) venom paralyses pairts o the body, stairtin wi the een, afore causin daith. Schaefer an his toxicologist Dietrich Mebs decidit Cleopatra uised a mixture o hemlock, wolfsbane an opium.

Plutarch, writin aboot 130 years efter the event, reports that Octavian succeedit in capturin Cleopatra in her mausoleum efter the daith o Antony. He ordered his freedman Epaphroditus tae guard her tae prevent her frae committin suicide, acause he allegedly wantit tae present her in his triumph. But Cleopatra wis able tae deceive Epaphroditus an kill hersel nivertheless. Plutarch states that she wis foond deid, her handmaiden Iras dyin at her feet, an anither handmaiden, Charmion, adjusting her croun afore she hersel fell. He then goes on tae state that an asp wis concealed in a basket o figs that wis brocht tae her bi a rustic, an, fyndin it efter eatin a few figs, she held oot her airm for it tae bite. Ither stories state that it wis hidden in a vase, an that she poked it wi a spindle till it got angry enough tae bite her on the airm. Feenally, he indicates that in Octavian's triumphal mairch back in Roum, an effigy o Cleopatra that haed an asp clingin tae it wis pairt o the parade.

Suetonius, writin aboot the same time as Plutarch, an aa says Cleopatra dee'd frae an asp bite.

Shakespeare gae us the feenal pairt o the image that haes come doun tae us, Cleopatra clutchin the snake tae her breast. Afore him, it wis generally agreed that she wis bitten on the airm.

Plutarch tells us o the daith o Antony. When his airmies desertit him an jynt wi Octavian, he cried oot that Cleopatra haed betrayed him. She, fearing his wrath, locked hersel in her monument wi anerlie her twa handmaidens an sent messengers tae tell Antony that she wis deid. Believin them, Antony stabbed hissel in the painch wi his swuird, an lay on his couch tae dee. Instead, the bluid flow stopped, an he begged ony an aw tae finish him aff. Anither messenger came frae Cleopatra wi instructions tae bring him tae her, an he, rejoicin that Cleopatra wis still alive, consentit. She wadna open the door, but tossed ropes oot o a windae. Efter Antony wis securely trussed up, she an her handmaidens hauled him up intae the monument. This nearly feenished him aff. Efter draggin him in throu the windae, thay laid him on a couch. Cleopatra tore aff her claes an covered him wi them. She raved an cried, beat her breasts an engaged in sel-mutilation. Antony tauld her tae calm doun, asked for a gless o wine, an dee'd upon finishin it.

The site o thair mausoleum is uncertain, tho it is thocht bi the Egyptian Antiquities Service, tae be in or near the temple o Taposiris Magna soothwast o Alexandria.

Cleopatra's son bi Caesar, Caesarion, wis proclaimed pharaoh bi the Egyptians, efter Alexandria fell tae Octavian. Caesarion wis captured an killed, his fate reportedly sealed whan ane o Octavian's advisers paraphrased Homer: "It is bad tae hae ower mony Caesars." This endit no juist the Hellenistic line o Egyptian pharaohs, but the line o aw Egyptian pharaohs. The three childer o Cleopatra an Antony wur spared an taken back tae Roum whaur thay wur taken care o bi Antony's wife, Octavia Minor. The dochter, Cleopatra Selene, wis marriet throu arrangements o Octavian tae Juba II o Mauretanie.

Character an cultural depictions

Cleopatra wis regardit as a great beauty, even in the auncient warld. In his Life of Antony, Plutarch remarks that "judgin bi the proofs which she haed haed afore this o the effect o her beauty upon Caius Caesar an Gnaeus the son o Pompey, she haed hopes that she wad mair easily bring Antony tae her feet. For Caesar an Pompey haed kent her when she was still a girl an inexperienced in affairs, but she wis goin tae visit Antony at the vera time when weemen hae the maist brilliant beauty". Later in the wirk, housomeivver, Plutarch indicates that "her beauty, as we are tauld, was in itsel no aathegither incomparable, nor such as tae strike those who saw her." Rather, what ultimately made Cleopatra attractive wur her wit, chairm an "sweetness in the tones o her voice."

Cassius Dio an aa spoke o Cleopatra's allure: "For she wis a wumman o surpassin beauty, an at that time, when she wis in the prime o her youth, she wis maist strikin; she an aa possessed a maist chairmin voice an knawledge o hou tae make hersel agreeable tae ivery ane. Being brilliant tae look upon and to listen to, wi the pouer tae subjugate ivery ane, even a love-satit man awready past his prime, she thought that it wad be in keepin wi her role tae meet Caesar, an she reposed in her beauty aw her claims tae the throne."

Thir accoonts influenced later cultural depictions o Cleopatra, which teepically present her uisin her chairms tae influence the maist pouerful men in the Wastren warld.

References

Freemit airtins

General
Cleopatra VII (VI) at LacusCurtius – Chapter XIII of E. R. Bevan's House of Ptolemy, 1923
Cleopatra , a Victorian childer's beuk bi Jacob Abbott, 1852, Project Gutenberg edition.
James Grout: Cleopatra pairt o the Encyclopædia Romana
"Mysterious Death of Cleopatra"  at the Discovery Channel
Cleopatra VII at BBC History

Paintins
Sir Thomas Browne: Of the Picture describing the death of Cleopatra (1672)
John Sartain: On the Antique Portrait of Cleopatra (1818)

69 BC births
30 BC daiths
Egyp
1st-century BC female rulers
Auncient Egyptian queens consort
Auncient Egyptian weemen in warfare
Daiths due tae snake bites
Egyptian queens regnant
Female Shakespearean chairacters
Pharaohs o the Ptolemaic dynasty
Ryal suicides in the clessical warld
Weemen in Hellenistic warfare

Cleopatra


People with color blindness cannot tell the difference between certain colors. They may not see colors at all.

Most color blindness is inherited, usually as simple Mendelian inheritance. Sometimes, it is the result of damage to the eyes, nerves, or the brain. It can be caused by coming into contact with certain chemicals.

Most color blindness is permanent. Some conditions can lead to temporary color blindness. During certain kinds of migraine, some people are unable to tell the difference between certain colors. There is no treatment cure for permanent color blindness.

Many more males are color blind than females. Between five and eight percent of males, but less than one percent of females, are color blind.

People usually think of color blindness as a disability. However, people who are color blind have one advantage: they are sometimes better at seeing through some types of camouflage.

History
In 1798, English chemist John Dalton published the first scientific article about color blindness. That was after he found out that he was color blind. The article was called "Extraordinary facts relating to the vision of colours [sic]". Because of this, the condition is sometimes called daltonism. As of 2009, the word daltonism is used only for the type of color blindness called deuteranopia.

Seeing color
There are three steps in the process of telling the difference between colors:
Light hits specialized nerve cells in the eye. Those cells are called receptors. Some of them are stimulated and create an electrical signal.
The signals move along nerves to special parts of the brain.
Those parts of the brain interpret the signals. The signals are changed into an image. This image is then carefully looked at to separate different objects, to see shapes and sometimes colors, and to link these to other kinds of information.

How the human eye sees colors

Inside the human eye is a part called the retina. The retina receives the images that the eye sees. It sends the images to the brain. The retina has two types of cells: Rod cells and Cone cells. They work in different types of light.

Rod cells receive the images that the eye sees when the light is dim, at night, or in a dark room.
Cone cells receive the images that the eye sees in normal daylight or in bright light. There are three types of cone cells. Each type has a different chemical photopsin and reacts to a different spectrum of light. One is specially sensitive to short wavelengths. Another is sensitive to medium wavelengths. The third is sensitive to long wavelengths. These wavelengths cover much of the visible light. Each color is "seen" as a result of how much each of the receptors is stimulated.

How the brain works out the colors
Parts of the thalamus and the visual cortex in the brain are involved in seeing, also seeing colors. Color blindness can therefore also result if these areas of the brain, the optic nerve or the retina have been damaged. These types of color blindness happen because of an accident. They are not inherited. Inherited forms of color blindness affect the retina only.

That way it is possible that only a part of the visual field is affected by color blindness, but in the rest, there is no color blindness.

Some types of color blindness, but not inherited color blindness, can be cured.

Causes of color blindness
There are several different problems that can cause color blindness.
If a person's eye has no cone cells, then they cannot see any color at all. They can only see shades of dark and light.
There are three types of cone cells in the human eye. If there are two types, a person will have a hard time to tell certain colors apart. If there is only one type, a person will not see color at all.
Sometimes cone cells change. This means that they no longer react to those wavelengths they should. A person will need more of a certain color to see this color. They see colors differently, and may not be able to tell certain colors apart. Most of these people do not know they are color blind, as they have little difficulty telling colors apart in most cases.
There may be nothing wrong with the eye, but the nerves that transport the information or the area in the brain that interprets it may be damaged. This means that the signal is interpreted the wrong way. The damage may be permanent, or it may be temporary. Certain conditions of the brain, like a migraine can change the way people see colors.

Different types of color blindness

Total color blindness
Total color blindness is very rare. People who suffer from it can only see in black, gray and white. They can perceive only differences in brightness and do not see color.  This is called monochromacy.

There are two main types of total color blindness:
 Rod monochromacy (achromatopsia): The retina has no cone cells. This makes it difficult to see even lights of a normal level; this means that people who suffer from it are almost blind. It occurs almost only on the island of Pingelap, a part of the Pohnpei state in the Federated States of Micronesia. There it is called maskun: about one person in 12 of the population has it. The island was hit by a storm in the 18th century. Very few men survived the storm. One of them carried a gene for rod monochromacy. Today, several hundred people live on the island, about 30% have this gene.
 Cone monochromacy: The retina has both rods and cones, but only one type kind of cone. People who suffer from this will be able to see patterns well, in normal daylight, but they will not see hues.

Red/green color blindness
There are two kinds of red-green color blindness: protanopia or deuteranopia. Deuteranopia is the most common form of color blindness; between five and ten percent of males suffer from it. It is called Daltonism because John Dalton discovered it. Those affected have trouble telling the difference between red and green. As seen by protanopes (people suffering from protanopia), red is darkened. Most often, this is because they lack the receptors for long (protanopia) or medium (deuteranopia)-length light waves or because these receptors have changed their sensitivity.

Blue/yellow color blindness
Although the name is blue-yellow color blindness (tritanopia), people affected by this type of color blindness can usually tell the difference between blue and yellow. Instead they cannot tell the difference between blue and green, and also yellow and violet.  It is different from the other types of color blindness because it is not linked to sex.  It is equally possible for males or females to develop blue-yellow color blindness. It is caused by having few or no cones in the retina which can sense short wavelength light.

Other causes of color blindness
Sometimes, people do not have problems seeing color, but their brain has trouble "telling" the color, and interprets it wrong. It is also possible that only certain parts of the eye have color blindness; people may become color blind because of other diseases, but after the disease goes away, see normally again. This seems to be the case with certain forms of migraine.

How color blindness is inherited
Males have one X and one Y chromosome; females have two X chromosomes. Many of the genes involved in making color vision work are on the X chromosome: they are sex linked. For this reason, men are more often affected by color blindness than women.

The "color blind" gene allows non-color blind people to see the difference between red and green. The gene is located on the X chromosome.  This means that a male will be color blind if the single X he inherits from his mother contains the color blind version of the "color blind" gene. A female will inherit color blindness only if she inherits two X chromosomes containing defective (mutant) color gene alleles. In other words, a female needs to inherit "color blind" genes from both parents in order to be color blind.

Testing someone for color blindness

The Ishihara plate test has been in use since 1917.  Each plate has an image with dots of different size and color. People will then see different images (most often numbers). Those with certain types of color blindness will see different numbers from those not affected by color blindness.

Because many young children have not learned numbers yet, other tests have been developed. They use symbols, like a square, a circle or a car instead of numbers.

Design changes
A color code is when there is much information in the color of certain item. Such codes cannot be understood easily by those who are color blind. For this reason, color should not be used alone to give information.  Good graphic design avoids using color coding or color differences alone to give information. This does not only help color blind people, but also normally sighted people.

Cascading Style Sheets can be used on web pages. They allow to give a different color scheme for color blind people. Certain color scheme generators help graphic designers see color schemes as eight types of color blind people see them.

Color blindness is very sensitive to changes in material. A red-green color blind person may be unable to see the difference between colors on a map printed on paper. The same map on a computer screen or television may appear normally. In addition, some color blind people find it easier to tell the difference between colors on artificial materials, such as plastic or in acrylic paints, than on natural materials, such as paper or wood. Thirdly, for some color blind people, color can only be distinguished if there is enough color: thin lines might appear black, but a thicker line of the same color can be seen in the correct color.

In certain cases when it is important to understand information very quickly, the visual system may drop the colors, and only work in shades of gray. This is important to know when designing the interfaces for objects that need to be used in an emergency situation, like emergency brakes, or emergency telephones.

Because color blind people may not see the difference between colors such as red and green, some countries, such as Romania have refused to give them driving licenses. In Romania, people have started to change the laws so that color blind people will also be able to drive legally.

In the United Kingdom, electricity wires in houses used to be red, black and green. They were changed to brown, blue and green/yellow to help color blind people see the difference between the "live" and "earth" wires.

What color blindness is not
Many people do not understand color blindness. People who are color blind never swap the colors they are blind to.  They may have trouble telling two colors from one another. That way they may have a problem finding the right kind of apple in the supermarket. The image below first shows the way that two apples look to a person with normal vision, and then the way it looks to a person with red-green color blindness. The left apple is a Braeburn; it is red in color. The apple on the right is a Granny Smith; it is green. To someone with red-green blindness, the apples look like they are almost the same color.

References

Diseases and disorders of the eye
Genetic disorders
Tests

Color blindness


Plumbing (which comes from the Latin word plumbum, which means lead, as pipes were once made from lead) is the job of working with pipes, tubing and plumbing fixtures for drinking water systems and getting rid of waste. A plumber is someone who fixes or puts in piping systems, plumbing fixtures and equipment such as water heaters. Many plumbers are construction workers. The plumbing industry is an important part of every developed economy because people need clean water and safe ways to move and store waste.

Plumbing also refers to a system of pipes and fixtures put in a building to move water and the get rid of waste that is in water. Plumbing is different from water and sewage systems because plumbing system serves one building, while water and sewage systems serve a group of buildings or a city.

History

Plumbing was very rare until modern cities grew in the 19th century. At about the same time, public health leaders began wanting better systems to get rid of waste. Before this, people got rid of waste by collecting it and dumping it onto the ground or into rivers. However, there were some plumbing pipes in the city settlements of the Indus Valley Civilization by 2700 B.C. Plumbing was also used during the ancient civilizations such as the Greek, Roman, Persian, Indian, and Chinese civilizations as they built public baths and needed drinking water, and somewhere to drain waste. The Romans used pipe inscriptions to stop people from stealing water.

These systems did not improve much over the years. There were almost no improvements from the time of the Roman aqueducts and sewers until the 19th century. Eventually the development of separate, underground water and sewage systems got rid of open sewage ditches and cesspools. Most large cities today send solid wastes through pipes to sewage treatment plants. Treatment separates water from waste and makes the water more pure before it goes into streams or other bodies of water. Most places stopped using lead for drinking water after World War II because of the dangers of lead poisoning. At this time, copper piping was started because it was safer than using lead pipes.

Materials
Water systems in ancient times used gravity to move water. They used pipes or channels usually made of clay, lead, bamboo or stone. Today, water-supply systems use a network of high-pressure pumps, and pipes are now made of copper, brass, plastic, or other nontoxic material. Drain and vent lines are made of plastic, steel, cast-iron, and lead. Lead is not used in pipes today because it can be poisonous.

The 'straight' sections of plumbing systems are of pipe or tube.  A pipe is usually made by casting or welding, where a tube is made through extrusion.  Pipe usually has thicker walls and may be threaded or welded, where tubes have thinner walls, and needs special joining techniques such as 'brazing', 'compression fitting', 'crimping', or for plastics, 'solvent welding'.

As well as the straight pipe or tubing, many fittings are required in plumbing systems, such as valves, elbows, tees, and unions.

Plumbing fixtures are designed for the people who use the water.  Some examples of fixtures include water closets (also known as toilets), urinals, bidets, showers, bathtubs, utility and kitchen sinks, drinking fountains, ice makers, humidifiers, air washers, fountains, and eye wash stations.

Regulation
Much of the plumbing work in places where many people live is done under government rules. Putting in plumbing and fixing plumbing generally must be done according to plumbing and building codes to protect the people who live or work in the buildings.

References

Water infrastructure
Waste
Engineering

Plumbing


Danger (also risk or peril) is the possibility of something bad happening. A situation in which there is a risk of something bad happening, is called dangerous, risky or perilous.

People often take risks, or do things that might hurt them. An example of this is crossing the road without looking carefully. There is a risk that you might get hit by a car.

Anything that involves a risk of injury or to health can be described as dangerous. Smoking is dangerous to health.  Being around some animals is dangerous because they might attack humans.

Measuring danger
There are a few different ways that danger can be quantified - put into numbers.

Probability
probability measures how dangerous something is.  It uses a math equation to find the risk that a certain event might happen.  In epidemiology, risk is defined as the number of events that did happen, divided by the number of events that could have happened. For example, if the risk of babies dying after birth in a population is reported as 1/1000, it means that out of every 1000 babies born, 1 is likely to die.

Risk and prevalence
Prevalence is the number of people in a population that have a certain disease.

Risk is the number of new cases of disease, divided by the number of people who could get the disease.  For example, during an outbreak of the flu, risk would be the number of people who get the flu, divided by the number of people who were exposed to the flu virus.

Risk assessment
A risk assessment is a list of things that could go wrong. In many Western countries, when teachers take children on an outing, they may have to fill in a risk assessment form which lists the possible dangers and says what they should do to stop bad things from happening (e.g. accidents or children getting lost).

Related pages

Adventure
Threat
Safety

Epidemiology
Safety

Danger


The Eastern Orthodox Church, officially the Orthodox Church, is a Christian church. Their type of Christianity is also called Orthodox Christianity or Orthodoxy. Their members are called Orthodox Christians, although there is another group of Churches called Oriental Orthodox that is not in communion with the Orthodox Church. There are about 300 million Orthodox Christians in the world. Most Orthodox Christians are found in Eastern Europe and the Middle East.

The Eastern Orthodox Church teaches that it is the Church started by Jesus Christ in his instructions to the Apostles. It practices what it understands to be the original Christian faith and maintains the sacred tradition passed down from the apostles.

The worship service is known as the Divine Liturgy. The beliefs and rituals of the service are similar to the Eucharist in the Roman Catholic Church.

History
In 395, the Roman Empire was split into a western part and an eastern part. The western part lasted to the 5th or 6th century. Τhe exact dates are a point of debate. The eastern part, which is commonly called Byzantine Empire, lasted until the 15th century. The split of the Roman Empire also affected the church, which developed differently in both parts. In 1054, there was the Great Schism. The western part developed what is now the Roman Catholic Church, and the eastern part is now called Eastern Orthodox Church. In the west, there is the Patriarch of Rome, who is commonly called the Pope. In the east, there is the Patriarch of Constantinople. Because of historical developments, many Eastern Orthodox churches also have a local Patriarch. In the west, the Pope is an absolute leader. The Patriarch of Constantinople is the "first among equals"; his power is not absolute, as seen when meeting with other Patriarchs. His power is the same of all bishops.

Important things to know about the Orthodox Churches
Some holidays include Christmas and Easter.

Orthodox believe in everything in the Nicene Creed:
I believe in one God, the Father, the Almighty, Creator of heaven and earth and of all things visible and invisible.
And in one Lord Jesus Christ, the only begotten Son of God, begotten of the Father before all ages.
Light of Light, true God of true God, begotten not created, of one essence with the Father through whom all things were made.
For us men and for our salvation He came down from heaven and was incarnate with the Holy Spirit and the Virgin Mary and became man.
He was crucified for us under Pontius Pilate, and He suffered and was buried.
On the third day He rose according to the Scriptures.
He ascended into heaven and is seated at the right hand of the Father.
He will come again in glory to judge the living and dead. His kingdom shall have no end.
And in the Holy Spirit, the Lord, the Giver of life, who proceeds from the Father, who together with the Father and the Son is worshiped and glorified, who spoke through the prophets.
In One, Holy, Catholic, and Apostolic Church.
I acknowledge one baptism for the forgiveness of sins.
I expect the resurrection of the dead.
And the life of the ages to come. Amen.
In summary, they believe in one God. He has three parts (Father, Son & Spirit) which are one and the same (of one essence). As the Son (Jesus), he arrived from Heaven, died, and resurrected. He will eventually return as a Judge for all of humanity, as mentioned in the Bible.

The Church Today

The many churches of the Orthodox Church are distinct in terms of administration and local culture, but for the most part exist in full communion with one another. Most of these churches are led by patriarchs. Most patriarchs recognize the Patriarch of Constantinople as their spiritual leader.

The following listing contains a selection of Eastern Orthodox Churches. Unless otherwise stated, they are in communion:
 Mount Athos (a community of monasteries)
 Albanian Orthodox Church
 Antiochian Orthodox Church
 Bulgarian Orthodox Church
 Greek Orthodox Church
 Greek Orthodox Church of Alexandria
 Church of Mount Sinai (one monastery)
 Russian Orthodox Church
 Russian Orthodox Church Outside Russia
 Romanian Orthodox Church

In the 17th century a group of people split from the Eastern Orthodox Church because they did not agree with some changes that were introduced. These people are known as Old Believers today. There are two big groups of Old Believers and a few smaller ones. Old Believers are not in communion with the other Eastern Orthodox Churches.

Related pages
 Christianity
 Eastern Christianity
 History of Christianity
 Old Calendarists
 Oriental Orthodox Church

References
The Orthodox Church; 455 Questions and Answers. Harakas, Stanley H. Light and Life Publishing Company, 1988. ()

The Orthodox Church New Edition Publisher: Penguin (Non-Classics); 2 edition

Other websites

 OrthodoxWiki
 Orthodox Research Institute
 List of most patriarchates
 Directory of Orthodox Internet Resources
 PATRIARCHIA.RU

Eastern Orthodox Church


An orchestra is a group of musicians playing instruments together. They make music. A large orchestra is sometimes called a "symphony orchestra" and a small orchestra is called a "chamber orchestra". A symphony orchestra may have about 100 players, while a chamber orchestra may have 30 or 40 players. The number of players will depend on what music they are playing and the size of the place where they are playing. The word "orchestra" originally meant the semi-circular space in front of a stage in a Greek theatre which is where the singers and instruments used to play. Gradually the word came to mean the musicians themselves.

The conductor

The orchestra is directed by a conductor. He/she helps the players to play together, to get the right balance so that everything can be heard clearly, and to encourage the orchestra to play with the same kind of feeling. Some small chamber orchestras may play without a conductor. This was usual until the 19th century when the orchestras got very big and needed a conductor who made decisions and stood in front so that all the players could see him.

The instruments

The instruments of the orchestra are divided into districts: the strings, woodwind, brass and percussion. Each section (group of instruments) will have a player who is the "Boss". The principals will make decisions about seating arrangements, and about technical ways of playing the music: for example the principal of the string sections will make sure all the players move their bows up and down in the same direction. The violins are divided into first and second violins. The first violins usually have the tune while the seconds, most of the time, are part of the accompaniment. The principal of the first violin is the leader (or concertmaster) of the orchestra. In a professional orchestra they will be the most highly paid member of the orchestra.

The string family

The strings are the biggest section, although there are only five kinds of instruments: violin, viola, cello, double bass, and harp. This is because they are playing most of the time and usually form the basis of the music. If they are not playing the tune they will probably be accompanying. The first and second violins play different notes: the firsts usually have the tune. The strings sit at the front of the stage in a fan-shape in front of the conductor. The first violins are on the conductor's left, then come the second violins, then the violas and then the cellos. The double basses are behind the cellos. Some conductors prefer to have the second violins on their right and the cellos between the first violins and violas (see image of the Dohnanyi Orchestra).

The woodwind family

The woodwind sit in one or two rows (depending on the size of the orchestra) behind the strings. There are five main woodwind instruments: flute, oboe, clarinet, saxophone, and bassoon. Each of these instruments also come in different versions:

The flute has a small version called the piccolo which plays an octave higher. It is the highest instrument in the orchestra. Occasionally there is an alto flute which is longer and plays a fifth (half an octave) lower than the flute. Most woodwind instruments need a reed, but the flute does not have a reed.

The bassoon has a larger version: the contrabassoon or double bassoon which sounds an octave lower. It is one of the lowest instruments in the orchestra.

The clarinet has a larger version as well; the bass clarinet. It reaches the same depth as a bassoon. Usually only one is found in a modern orchestra. There is also an alto clarinet but because it plays the same part an alto saxophone plays, it is typically regarded as an unnecessary instrument.

A formal orchestra will always consist of two of the four main instruments. The variations of the instruments are used where the piece asks for it. Usually, the newer pieces written after 1850 will have more instruments.

Sometimes a player will double on these extra instruments, for example: one of the flute players may also play the piccolo in the same piece. It depends on the piece of music. Obviously a player cannot play the flute and piccolo at the same time. If the two instruments do play at the same time an extra player will be needed for the piccolo.

The brass family

The brass section has four sections: trumpet, trombone, French horn, and tuba. Some of these come in several sizes. The article on transposing instruments explains more about it. The trumpet may have several slightly different sizes. The lowest kind is a bass trumpet. The trombone may be an alto, tenor, bass or contrabass trombone. The French horn, like the other brass instruments, has changed over the years. Modern horns have at least three valves and are usually in F. They often sit in a different place to the other brass. The tuba comes in different sizes and the player or conductor must decide which to use for the piece they are playing. There are large ones called contrabass tubas. A small tuba is commonly also seen and is called a euphonium or a baritone horn.

The percussion family

The percussion section has the largest variety of instruments. such as: the tambourine, the triangle, the fabulous loud gong, the crashing cymbals and the ringing bell. The timpani (or "kettle drums") can be tuned to particular notes. They are the most common percussion instrument. Composers such as Haydn and Mozart nearly always used them, even with their small orchestras. This is the most commonly used percussion instruments and is used in almost all pieces.

The rest of the percussion section can include tuned percussion instruments like the xylophone. Non-tuned percussion can be other kinds of drum like bass drum, snare drum, and a variety of others: simple to name the most common ones. The principal percussion player will have to decide which player will play which instrument(s). The percussionists have to work well together as a team so all parts can be covered.

The history of the orchestra

It is difficult to say when the orchestra was invented because instruments have played together for many centuries. If we say that an orchestra is a group of string instruments with several players playing the same part, and that there may be wind instruments (i.e. woodwind and brass) or percussion playing as well, then the 17th century is the time that orchestras started. In Paris in 1626 King Louis XIII had an orchestra of 24 violins (called "24 Violons du Roi"). Later in the century the English king Charles II wanted to be like the French king and so he, too, had a string orchestra. Gradually the other instruments were added. At this time there was usually someone playing the harpsichord (the continuo part). It was often the composer himself, who would have conducted from the keyboard at important moments like the beginning and end of the piece.

Clarinets came into the orchestra at the end of the 18th century, and trombones at the beginning of the 19th century. Orchestras were still quite small, though. The saxophone was invented in the middle of the 19th century, but although they started to use it in orchestras, it soon became an instrument that was used in wind bands and later jazz bands. The opera composer Richard Wagner made the orchestra much bigger because he kept asking for extra instruments. He asked for a bass clarinet in his opera Lohengrin, and for his cycle of four operas called The Ring of the Nibelung he asked for an exact number of players: 16 first violins, 16 second violins, 12 violas, 12 cellos, 8 double basses, 3 flutes and piccolo, 3 oboes and cor anglais, 3 clarinets and bass clarinet, 3 bassoons, 3 trumpets and bass trumpet, 3 tenor trombones and a double bass trombone, 8 horns with 4 of them playing a specially designed tuba, a bass tuba, percussion, and 6 harps.

Not all pieces written after that need quite such a large orchestra, but concert halls had become bigger and composers had got used to a bigger variety of sounds. Later composers sometimes added all sorts of unusual instruments: wind machine, sandpaper block, bottles, typewriter, anvils, iron chains, cuckoo, Swannee whistle etc. None of these are normal orchestral instruments. Sometimes a piano is used in the percussion section, e.g. Igor Stravinsky used one in Petrouchka. Sometimes voices are also used.

The orchestra today

Today orchestras can usually be heard in concert halls. They also play in opera houses for opera and ballet, or in a large stadium for huge open-air concerts. Orchestras may record in studios for making CDs or recording music for movies. Many of them can be heard easily and cheaply every summer in London at the BBC Proms.

Some of the greatest orchestras today include: the New York Philharmonic Orchestra, the Boston Symphony Orchestra, the Chicago Symphony Orchestra, the Cleveland Orchestra, the Los Angeles Philharmonic Orchestra, the London Symphony Orchestra, the London Philharmonic Orchestra, the BBC Symphony Orchestra, the Royal Concertgebouw Orchestra, the Vienna Philharmonic Orchestra, the Berlin Philharmonic Orchestra, the Leipzig Gewandhaus Orchestra, the Singapore Symphony Orchestra, the St Petersburg Philharmonic Orchestra, the Israel Philharmonic Orchestra, and the NHK Symphony Orchestra (Tokyo). Opera houses usually have their own orchestra, e.g. the orchestras of the Metropolitan Opera House, La Scala, or the Royal Opera House.

In many countries there are opportunities for school-age children who play instruments well to play in youth orchestras in their areas. In Britain some of the very best are selected to play in the National Youth Orchestra of Great Britain. Other world-famous youth orchestras include the Orquesta Sinfónica Simón Bolívar, Gustav Mahler Youth Orchestra, the European Union Youth Orchestra and the West-Eastern Divan Orchestra.

References
 The New Grove Dictionary of Music and Musicians, 1980; ed. Stanley Sadie;
 Orchestration by Walter Piston, London 1965.

Related pages
Orchestration

Orchestra


Achille-Claude Debussy (born St Germain-en-Laye, 22 August 1862; died Paris, 25 March, 1918) was a French composer. He was one of the most important composers of the early 20th century. Most of his compositions are for orchestra or for piano. He also wrote some songs, chamber music and one opera. He made his music very different from the Romantic style that other composers were using at the time. He is often called an Impressionistic composer because he was influenced by the group of painters called "Impressionists". They were not so much interested in making their paintings look exactly like the real world, but preferred to paint things such as the effect of the sunlight shining on water. Debussy often did this in his music, which creates a special atmosphere.

Life
Claude Debussy did not have an easy childhood. His father was a travelling salesman and his mother worked as a seamstress. He learned the piano when he was young and was inducted into the Paris Conservatoire at age 11. For a time it seemed that he would become a concert pianist, but he did not do well enough in his examination. After winning an important prize, the Prix de Rome, he went to Rome for two years but he did not enjoy it. He visited Bayreuth in 1888 and 1889 to hear Wagner's operas but he did not like them. He preferred sounds like that of the Javanese gamelan which he heard in Paris at the World Exhibition.

In 1899 he married a young woman named Rosalie Texier. He got a job as music critic of a journal called La revue blanche. He wrote his opera Pélleas et Mélisande which was performed at the Opéra-Comique. It was extremely successful and was performed 100 times there during the next ten years. He wrote exciting music for orchestra: Fêtes galantes and a work called La Mer (The Sea) which he worked at while staying in Brighton on the south coast of England. It is one of the most exciting pieces of music about the sea.

Debussy was starting to become very famous. His personal life changed. He left his wife because he had fallen in love with Emma Bardac who was an amateur singer for whom Gabriel Fauré had written a song cycle La Bonne Chanson. Her husband was a banker. She bought an apartment and Debussy lived with her there for the rest of his life. They had a daughter called Chou-Chou, born in 1905. They married in 1908.

Debussy's next orchestral work was called Images. He began composing a set of preludes for piano. Other works followed: Khamma, Le martyre de St Sébastian and the ballet Jeux, which was produced in 1913 by Dyagilev's company. People soon forgot about this work because only two weeks later the same ballet company produced Stravinsky's Rite of Spring which caused a riot.

By this time Debussy was ill with colorectal cancer. His visit to London in 1914 was his last trip to another country. He wrote more piano works: a set of Études and a piano duet called En blanc et noir (In white and black). He planned to write six sonatas, each for a different group of instruments, but he only wrote three of them: one for cello and piano, one for flute, viola and harp and one for violin and piano. The Sonata for violin and piano (1917) was the last work he played in public (he played the piano part). He died of colorectal cancer in 1918.

His music

Saint-Saëns, for example, did not understand the way that the musical ideas flowed gently into one another. He was always an enemy of Debussy.

There is a lot of variety in Debussy's piano music. Some of it is very difficult to play, e.g. the Études and pieces such as L'isle joyeuse (The happy island). Other collections are much simpler, e.g. Suite bergamasque which includes the very popular piece called Clair de lune (Moonlight). He wrote two books of preludes. Each of the pieces has a title, but the titles are printed at the end of each piece, as if he did not want the listener to know what it was about until afterwards.

Debussy wrote wonderfully for the voice, making the music just right for the rhythm of the French language. This can be heard in his songs and his opera. Using melodies and harmonies which are often quite simple he creates a special kind of dream-world which can be very powerful. He often uses the whole tone scale and the pentatonic scale which give the music a hazy feeling because it does not seem to be clearly in one particular key. He liked to use unusual chords just for their own sake, not in order to make them lead to a particular key. He also used the old scales known as the church modes.

Debussy's music had a great influence on many composers in the 20th century. John Cage, Olivier Messiaen, Pierre Boulez, Karlheinz Stockhausen and Frederico Mompou all learned from listening to his music.

References
Groves Dictionary of Music Online

Cancer deaths in France
Deaths from colorectal cancer
20th-century French composers
1862 births
1918 deaths

Claude Debussy


A trait, or character, in biology is a feature of a living thing. It is part of an organism's phenotype.

Every living thing, from tiny organisms like bacteria, to plants, animals and humans, has some characteristics which make it special. Thus an elephant has tusks, large size and weight, large ears and very large molar teeth (et cetera). These are typical characters of the African and Indian elephants.

Biologists call those traits. The living thing is built in a certain way; this is its anatomy, its structure or body. The physical structure works in a certain way; this is its function, the way its body works. An animal also acts in a certain way; this is its behavior.

The way that a living thing is structured, the way its body works and the way that it acts are all traits. The basic traits are shared by all the members of the group, that is why they are put in the same group. Other traits are only shared by a small number of the group.

For example:
 It is an anatomical trait of giraffes to have long necks. All giraffes have this trait.
 It is a physiological function of birds to lay eggs to produce their young. All birds have this trait.
 It is part of the behaviour of wolves to live and hunt in packs; it is part of the behaviour of cats to live alone or in small family groups, and to hunt alone. These characteristic behaviours are also traits.

Traits are heritable: they can be passed on from one generation to the next by genes. Mendel's work involved the inheritance of traits on pea plants. The whole group of traits of an organism is its phenotype.

Trait versus character
Different sources use the term differently. 'Trait' competes with the term 'character'.

Synonyms
According to some authorities, trait and character are synonyms:
The Dictionary of Genetics: "For trait, see character" and "Character: any detectable phenotypic property of an organism; synonymous with phenotype, trait".

'Trait'  as a sub-character
Some sources use both terms:
"Any detectable variation of an inherited character. It is the expression of genes as part of the phenotype".

This works well with Mendelian characters. In such cases, a character is a feature of a species which may present as various traits. Examples:
Eye color = character
Blue eye color = trait1
Brown eye color = trait2
Appearance of pea = character
wrinkled = trait1
smooth = trait2

But not all characters are inherited in the simple manner of Mendel's pea characters. For example, an animal's weight is a character, but many genes contribute to it, and so does the animal's environment from birth. Weight is a) continuous rather than discrete (separate steps), b) polygenic (controlled by a number of genes), and c) because weight is influenced by both heredity and environment.

Only 'character' used
To avoid this issue, some sources use only the term character. Futuyma uses this system for Mendelian characters:
Eye color = character
Blue eye color = character state1
Brown eye color = character state2
Appearance of pea = character
wrinkled = character state1
smooth = character state2
This use of 'character state' allows Futuyma to use terms such as 'ancestral state' and 'derived state' when talking about the evolution of characters.

References

Evolutionary biology
Classical genetics

Trait