Cryptography, or cryptology,  is the practice and study of hiding information. It is sometimes called code, but this is not really a correct name. It is the science used to try to keep information secret and safe.

Modern cryptography is a mix of mathematics, computer science, and electrical engineering. Cryptography is used in ATM (bank) cards, computer passwords, and shopping on the internet.

When a message is sent using cryptography, it is changed (or encrypted) before it is sent. The method of changing text is called a "code" or, more precisely, a "cipher". The changed text is called "ciphertext". The change makes the message hard to read. Someone who wants to read it must change it back (or decrypt it).  How to change it back is a secret.  Both the person that sends the message and the one that gets it should know the secret way to change it, but other people should not be able to. Studying the cyphertext to discover the secret is called "cryptanalysis" or "cracking" or sometimes "code breaking".

Different types of cryptography can be easier or harder to use and can hide the secret message better or worse. Ciphers use a "key" which is a secret that hides the secret messages. The cryptographic method needn't be secret. Various people can use the same method but different keys, so they cannot read each other's messages. Since the Caesar cipher has only as many keys as the number of letters in the alphabet, it is easily cracked by trying all the keys. Ciphers that allow billions of keys are cracked by more complex methods.

Since the time of Caesar, many improved cyphers have been made.  Some involved clever mathematics to resist clever cryptanalysis.  During the 20th century computers became the principle tool of cryptography.

Symmetric
In a symmetric-key algorithm, both the sender and receiver share the key. The sender uses the key to hide the message. Then, the receiver will use the same key in the opposite way to reveal the message. For centuries, most cryptography has been symmetric. Advanced Encryption Standard is a widely used one. However this is not to be confused with symmetry.

Asymmetric
Asymmetric cryptography is harder to use. Each person who wants to use asymmetric cryptography uses a secret number (a "private key") that is not shared, and a different number (a "public key") that they can tell everyone. If someone else wants to send this person a message, they'll use the number they've been told to hide the message. Now the message cannot be revealed, even by the sender, but the receiver can easily reveal the message with his secret or "private key". This way, nobody else needs to know the secret key.

Asymmetric cryptography generally takes more time and requires more computer power, therefore it is not used most of the time.  Instead, it is often used for computer signatures, when a computer must know that some data (like a file or a website) was sent from a certain sender. For example, computer software companies that release updates for their software can sign those updates to prove that the update was made by them, so that hackers cannot make their own updates that would cause harm. Websites that use HTTPS use an popular algorithm named RSA to create certificates, that show they own the website and that it is secure. Computers can also use asymmetric ciphers to give each other the keys for symmetric ciphers.

Computers
Computers can calculate quickly. They can do very strong encryption, and most 21st century cryptography uses them. Examples are computer algorithms like RSA, AES, and there are many others.  Using good algorithms like these can make it very hard to read the information that is sent.

People
Because people are slower than computers, any cryptography they use can probably be broken if enough of the secret way to change it is known.

Simple forms of cryptography that people can do without machines are Caesar ciphers and transposition ciphers, but many other kinds were used before computers were used.

References

Other websites
 Importance of cryptography
 What is symmetric cryptography
 Cryptography -Citizendium

Computer security
Computer science
Human communication

Cryptography


Volcanism (or vulcan activity) is the eruption of magma onto the surface of the Earth.

Magma under the crust is under very great pressure. When folding and faulting occur, cracks or fractures appear. These are lines of weakness.

When these lines of weakness develop downward in the crust and reach the magma, they will release the pressure in the magma. This allows magma to rise up along the lines of weakness and intrude into the crust. Some magma may even reach the Earth's surface as lava.

Volcanoes

Volcanoes are the places where magma reaches the earth's surface. The type of volcano depends on the location of the eruption and the consistency of the magma.

Intrusions

Intrusive volcanism is when magma is forced into the rocks that make up the Earth's crust.   When it cools and become solid while still underground, different features called plutons are formed. The rock formed is intrusive igneous rock.

These plutons will be exposed at the surface of land when the overlying rocks are removed after a long time of denudation (laid bare by erosion).

Major features formed by intrusive volcanicity include: batholith, laccolith, dyke, pipe and sill.
 Batholiths: Have large scale magma that has been solidified at the base of the mountain.
 Dyke: Is a small scale magma cooled within the earths crust that stands vertically to the existing rocks.
 Sill: Is a small scale magma cooled near the earths surface that lies horizontally to the existing rocks.
 Laccolith: A small scale magma that pushes the overlying layers of rocks to form a dome shaped structure.

Extrusions
The molten magma under great pressure forces its way through the fissure of underground rocks and reaches the Earth's surface to form "igneous extrusion".
Major extruded materials include gas, liquid and solid.

 Gas - sulphur, hydrogen, carbon dioxide and hot steam (geysers). When uprising magma decreases in pressure suddenly, gases within magma explode to the Earth's surface and cause destruction.
 Solid - pyroclast. Mainly composed of: country rock, fragments of solidified lava and fine materials (volcanic ash and dust). It can be classified by size into volcanic bombs, volcanic blocks, lapilli, volcanic ash and volcanic dust.
 Liquid - lava, hot springs.

Features formed are:
 Caldera: a large depression in a former volcanic site. When it is filled with water it is called a 'caldera lake'.
 Composite cones: a large volcanic mountain formed by solidified lava on the surface.
 Geysers: eruption of hot water and steam shooting into the air at regular intervals.
 Hot springs: springs of hot water that flow out continuously without shooting up into the air.

Notes

Other websites

Volcanology

Volcanism


A primary school, elementary school or grade school is a school for children between the ages of about five and eleven. It comes after preschool. When children finish learning at primary school, they go to secondary school.

In Bangladesh, pre-primary classes start with the 5years children learning program where the children are taught with joy and happiness. Students from ages six to eleven, they finish learning from primary school and prepared for secondary.

In the United Kingdom, a primary school usually comprises a nursery and the first seven years of a child's full-time learning. In Australia and the United States, primary school begins with kindergarten. It lasts for six years, usually until the fifth or sixth grade. In the U.S., "elementary school" is a more common term for public primary schools. "Primary school" is often used in private or independent schools. (In private or independent schools the government does not give the schools money.)

In India, "Primary Education" means the 'Nursery', the 'Kindergarten' and four years of regular schooling thereafter. Admission to Nursery classes is for children above two years so that the age is 6+ when entering Class I. Children are taught language (mother tongue and English) reading/writing skills, basic arithmetic and quite a good amount of general information about the country, people, statesmen, great people, flora & animals. However, this is true only for schools in the urban areas. Rural schools do not have Nursery or Kindergarten; they admit straight at Class I when the child is six. Further, the rural schools use the mother tongue as medium of instruction, not resorting to English in any way. Primary education is free in government schools. Moreover, rural primary schools offer free mid-day meals to children (the government pays for it) so that the drop out rate comes down. States of West Bengal, Maharashtra, Manipur, Nagaland and Kerala have done very good work in this way of spreading primary education.

In Singapore, primary school refers to those students who are normally between the ages of 7 to 12.  Primary School is classified as P1 to P6 for Primary 1 to Primary 6 respectively.  At the end of P6, students sit for a national level Primary School Leaving Exam (PSLE) which is used for placement into Secondary School.  Prior to Primary School, pupils attend Kindergarten School for 2 years.

In Germany, the primary school is called "Grundschule" and is normally from first grade to fourth grade so it is usually for children who are between six and ten years old. In some eastern states, for example in Berlin, the Primary School is for children up to age 12. In most German states the children start learning English in third grade on a very low level, they learn how to count and the names of the colors and other easy things. But because of that low level a German child who has finished Primary School is normally not able to form correct English sentences. In Primary School the children are prepared for the secondary education. Primary School students attend three main subjects: Math, German and General Knowledge ("Sachkunde"). In General Knowledge the children learn about nature, about their own body, how to ride a bicycle safely and something about the city they live in and of course about Germany. Beside those main subjects the children attend subjects like arts, music and Physical Education.

Types of educational institutions

Primary school


415协议是美国各大学研究生院针对某些学生同时接受几所学校的含有财政资助的入学邀请,却在事后反悔无法前来就读而导致一些学额浪费的现象,所达成的共同协议。此协议并不是一份法律合同,而且只在美国实行,并且只对签署该协议的部分美国大学适用。值得注意的是,即使一些学校加入了415协议,也可以和学校协商对承诺日期进行更改。

协议主要内容
学生在4月15日之前没有答复含有财政资助的入学邀请的义务,学校如果设定较早的答复期限则违反协议意图。对已接受的入学邀请,学生在4月15日的截止期限前可以自由放弃。如果学生接受入学邀请且没有在4月15日前表示放弃,或在4月15日后接受入学邀请,那么在没有得到该学校书面允诺的情况下,不应擅自接受其他入学邀请。类似地,学校在4月15日后发出的入学邀请是有条件的,使其生效需要展示此前曾接受学校的书面允诺。这一协议目前在执行上比较松散,学生和学校往往可以在任何时间进行协商。不过它仍然从一定程度上规范了学校的招生行为,解决了以前学校各自设限要求学生答复的行为。

415协议英文原文
'Acceptance of an offer of financial support (such as a graduate scholarship, fellowship, traineeship, or assistantship) for the next academic year by a prospective or enrolled graduate student completes an agreement that both student and graduate school expect to honor. In that context, the conditions affecting such offers and their acceptance must be defined carefully and understood by all parties.Students are under no obligation to respond to offers of financial support prior to April 15; earlier deadlines for acceptance of such offers violate the intent of this Resolution. In those instances in which a student accepts an offer before April 15, and subsequently desires to withdraw that acceptance, the student may submit in writing a resignation of the appointment at any time through April 15. However, an acceptance given or left in force after April 15 commits the student not to accept another offer without first obtaining a written release from the institution to which a commitment has been made. Similarly, an offer by an institution after April 15 is conditional on presentation by the student of the written release from any previously accepted offer. It is further agreed by the institutions and organizations subscribing to the above Resolution that a copy of this Resolution should accompany every scholarship, fellowship, traineeship, and assistantship offer.'

外部链接
415协议和签署该协议的学校名单
美国教育部提供的有关资料

美國教育

415协议


A regime is the leader and other people who run a government of a sovereign state.

There are many kinds of regimes.  They can achieve power in many ways.  Depending on the time and place and local civics like the electoral system, they can lose power in many ways too.  The most common way for a regime to lose power was a coup, invasion or revolution until the 20th century.  After that it became very dangerous and difficult to use these methods.  Peaceful regime change is usually by an election - this method is now used by more than half the people on the Earth.  It is called representative democracy.  Such regimes are often called administrations to make it clear they are not dictators, and since the executive branch does not have all the power itself - it may share it with a legislative branch.  Also the judicial branch is separate.  The courts are not usually considered part of the regime.

However, some things are the same no matter how the regime achieved power:

The regime needs help among people outside the regime and government to stay in power - these may be in the military or a political party.
Military and police obey the regime's orders, and can kill people.  If they would not do so, then, it would be possible to change regimes by force.
Trade and tax is set by the regime, which can take money away.
The regime speaks for the whole country when dealing with other countries.

When many regimes negotiate at the United Nations or World Trade Organization, it does not matter at all how each regime got its power.  It matters only that they can agree and make everyone in their country do as the agreement says.

When someone wants a regime to change in another country, they usually are not able to do this by any means other than violence or interfering in its election.  This is common if a regime is threatened by another regime.

Forms of government

Regime


The Sun Also Rises is the first novel by American writer Ernest Hemingway. It portrays American and British expatriates who travel along the Camino de Santiago from Paris to the Festival of San Fermín in Pamplona and watch the running of the bulls and the bullfights. An early modernist novel, it received mixed reviews upon publication. Hemingway biographer Jeffrey Meyers writes that it is now "recognized as Hemingway's greatest work" and Hemingway scholar Linda Wagner-Martin calls it his most important novel.  The novel was published in the United States in October 1926 by Scribner's. A year later, Jonathan Cape published the novel in London under the title Fiesta. It remains in print.

The novel is a roman à clef: the characters are based on people in Hemingway's circle and the action is based on events, particularly Hemingway's life in Paris in the 1920s and a trip to Spain in 1925 for the Pamplona festival and fishing in the Pyrenees. Hemingway converted to Catholicism as he wrote the novel, and Jeffrey Herlihy-Mera notes that protagonist Jake Barnes, a Catholic, was "a vehicle for Hemingway to rehearse his own conversion, testing the emotions that would accompany one of the most important acts of his life."  Hemingway presents his notion that the "Lost Generation"—considered to have been decadent, dissolute and irretrievably damaged by World War I—was in fact resilient and strong. Hemingway investigates the themes of love and death, the revivifying power of nature and the concept of masculinity. His spare writing style, combined with his restrained use of description to convey characterizations and action, demonstrates his "Iceberg Theory" of writing.

Background
In the  1920s Hemingway lived in Paris as a foreign correspondent for the  Toronto Star, and traveled to Smyrna to report on the Greco–Turkish War. He wanted to use his journalism experience to write fiction, believing that a story could be based on real events when a writer distilled his own experiences in such a way that, according to biographer Jeffrey Meyers, "what he made up was truer than what he remembered".

With his wife Hadley Richardson, Hemingway first visited the Festival of San Fermín in Pamplona in 1923, where he was following his recent passion for bullfighting. The couple returned to Pamplona in 1924—enjoying the trip immensely—this time accompanied by Chink Dorman-Smith, John Dos Passos and Donald Ogden Stewart and his wife. The two returned a third time in June 1925 and stayed at the hotel of his friend Juanito Quintana. That year, they brought with them a different group of American and British expatriates: Bill Smith, Hemingway's Michigan boyhood friend,  Stewart, recently divorced Duff, Lady Twysden, her lover Pat Guthrie, and Harold Loeb.  Hemingway's memory spanning multiple trips might explain the inconsistent time frame in the novel indicating both 1924 and 1925. In Pamplona, the group quickly disintegrated. Hemingway, attracted to Duff, was jealous of Loeb, who had recently been on a romantic getaway with her; by the end of the week the two men had a public fistfight. Against this background was the influence of the young matador from Ronda, Cayetano Ordóñez, whose brilliance in the bullring affected the spectators. Ordóñez honored Hemingway's wife by presenting her, from the bullring, with the ear of a bull he killed. Outside of Pamplona, the fishing trip to the Irati River (near Burguete in Navarre) was marred by polluted water.

Hemingway had intended to write a nonfiction book about bullfighting, but then decided that the week's experiences had presented him with enough material for a novel. A few days after the fiesta ended, on his birthday (21 July), he began writing what would eventually become The Sun Also Rises.  By 17 August, with 14 chapters written and a working title of Fiesta chosen, Hemingway returned to Paris. He finished the draft on 21 September 1925, writing a foreword the following weekend and changing the title to The Lost Generation.

A few months later, in December 1925, Hemingway and his wife spent the winter in Schruns, Austria, where he began revising the manuscript extensively. Pauline Pfeiffer joined them in January, and—against Hadley's advice—urged him to sign a contract with Scribner's. Hemingway left Austria for a quick trip to New York to meet with the publishers, and on his return, during a stop in Paris, began an affair with Pauline. He returned to Schruns to finish the revisions in March. In June, he was in Pamplona with both Richardson and Pfeiffer. On their return to Paris, Richardson asked for a separation, and left for the south of France. In August, alone and depressed in Paris, Hemingway considered suicide and drafted a last will, but he completed the proofs, dedicating the novel to his wife and son.  After the publication of the book in October, Hadley asked for a divorce; Hemingway subsequently gave her the book's royalties.

Publication history

Hemingway maneuvered his publisher Boni & Liveright into terminating their contract with him so that The Sun Also Rises could be published by Scribner's instead. In December 1925, he quickly wrote  The Torrents of Spring, a satirical novella parodying Sherwood Anderson's novel Dark Laughter, and sent it to Boni & Liveright. His three-book contract with them included a termination clause should they reject a single submission. Unamused by the satire aimed at one of their most saleable authors, Boni & Liveright immediately rejected it and terminated the contract.  Within weeks Hemingway signed a contract with Scribner's, who agreed to publish The Torrents of Spring and all of his subsequent work.

Scribner's published the novel on 22 October 1926. Its first edition consisted of 5,090 copies, selling at $2.00 per copy. Cleo Damianakes illustrated the dust jacket with a Hellenistic design of a seated, robed woman, her head bent to her shoulder, eyes closed, one hand holding an apple, her shoulders and a thigh exposed. Editor Maxwell Perkins intended "Cleon's respectably sexy" design to attract "the feminine readers who control the destinies of so many novels".

Two months later the book was in a second printing with 7,000 copies sold. Subsequent printings were ordered; by 1928, after the publication of Hemingway's short story collection Men Without Women, the novel was in its eighth printing. In 1927, the novel was published in the United Kingdom by Jonathan Cape, titled Fiesta, without the two epigraphs. Two decades later, in 1947, Scribner's released three of Hemingway's works as a boxed set, including The Sun Also Rises, A Farewell to Arms, and For Whom the Bell Tolls.

By 1983, The Sun Also Rises had been in print continuously since its publication in 1926, and was likely one of the most translated titles in the world.  At that time, Scribner's began to print cheaper mass-market paperbacks of the book, in addition to the more expensive trade paperbacks already in print. In the 1990s, British editions were titled Fiesta: The Sun Also Rises. In 2006, Simon & Schuster began to produce audiobook versions of Hemingway's novels, including The Sun Also Rises. In May 2016, a new "Hemingway Library Edition" was published by Simon & Schuster, including early drafts, passages that were deleted from the final draft, and alternative titles for the book, which help to explain the author's journey to produce the final version of this acclaimed work.

Plot summary
On the surface, the novel is a love story between the protagonist Jake Barnes—a man whose war wound has made him unable to have sex—and the promiscuous divorcée Lady Brett Ashley. Jake is an expatriate American journalist living in Paris, while Brett is a twice-divorced Englishwoman with bobbed hair and numerous love affairs, and embodies the new sexual freedom of the 1920s. Brett's affair with Jake's Princeton friend Robert Cohn (whom the characters often refer to by his last name) causes Jake to be upset and break off his friendship with Robert; her seduction of the 19-year-old matador Romero causes Jake to lose his good reputation among the Spaniards in Pamplona.

Book One is set in the café society of young American expatriates in Paris.  In the opening scenes, Jake plays tennis with Robert, picks up a prostitute (Georgette), and runs into Brett and Count Mippipopolous in a nightclub. Later, Brett tells Jake she loves him, but they both know that they have no chance at a stable relationship.

In Book Two, Jake is joined by Bill Gorton, recently arrived from New York, and Brett's fiancé Mike Campbell, who arrives from Scotland. Jake and Bill travel south and meet Robert at Bayonne for a fishing trip in the hills northeast of Pamplona. Instead of fishing, Robert stays in Pamplona to wait for the overdue Brett and Mike. Robert had an affair with Brett a few weeks earlier and still feels possessive of her despite her engagement to Mike. After Jake and Bill enjoy five days of fishing the streams near Burguete, they rejoin the group in Pamplona.

All begin to drink heavily. Robert is resented by the others, who taunt him with antisemitic remarks. During the fiesta the characters drink, eat, watch the running of the bulls, attend bullfights, and bicker.  Jake introduces Brett to the 19-year-old matador Romero at the Hotel Montoya; she is smitten with him and seduces him. The jealous tension among the men builds--Jake, Mike, Robert, and Romero each want Brett. Robert, who had been a champion boxer in college, has a fistfight with Jake and Mike, and another with Romero, whom he beats up. Despite his injuries, Romero continues to perform brilliantly in the bullring.

Book Three shows the characters in the aftermath of the fiesta. Sober again, they leave Pamplona; Bill returns to Paris, Mike stays in Bayonne, and Jake goes to San Sebastián on the northern coast of Spain. As Jake is about to return to Paris, he receives a telegram from Brett asking for help; she had gone to Madrid with Romero. He finds her in a cheap hotel, without money, and without Romero. She announces she has decided to go back to Mike. The novel ends with Jake and Brett in a taxi speaking and thinking of what might have been.

Themes and analysis

Paris and the Lost Generation

The first book of The Sun Also Rises is set in mid-1920s Paris.  Americans were drawn to Paris in the Roaring Twenties by the favorable exchange rate, with as many as 200,000 English-speaking expatriates living there.  The Paris Tribune reported in 1925 that Paris had an American Hospital, an American Library, and an American Chamber of Commerce. Many American writers were disenchanted with the US, where they found less artistic freedom than in Europe. (For example, Hemingway was in Paris during the period when Ulysses, written by his friend James Joyce, was banned  and burned in New York.)

The themes of The Sun Also Rises appear in its two epigraphs. The first is an allusion to the "Lost Generation", a term coined by Gertrude Stein referring to the post-war generation; the other epigraph is a long quotation from Ecclesiastes: "One generation passeth away, and another generation cometh: but the earth abideth for ever. The sun also ariseth, and the sun goeth down, and hasteth to his place where he arose." Hemingway told his editor Max Perkins that the book was not so much about a generation being lost, but that "the earth abideth forever." He thought the characters in The Sun Also Rises may have been "battered" but were not lost.

Hemingway scholar Wagner-Martin writes that Hemingway wanted the book to be about morality, which he emphasized by changing the working title from Fiesta to The Sun Also Rises. Wagner-Martin argues that the book can be read either as a novel about bored expatriates or as a morality tale about a protagonist who searches for integrity in an immoral world. Months before Hemingway left for Pamplona, the press was depicting the Parisian Latin Quarter, where he lived, as decadent and depraved.  He began writing the story of a matador corrupted by the influence of the Latin Quarter crowd; he expanded it into a novel about Jake Barnes at risk of being corrupted by wealthy and inauthentic expatriates.

The characters form a group, sharing similar norms, and each greatly affected by the war. Hemingway captures the angst of the age and transcends the love story of Brett and Jake, although they are representative of the period: Brett is starved for reassurance and love and Jake is sexually maimed.  His wound symbolizes the disability of the age, the disillusion, and the frustrations felt by an entire generation.

Hemingway thought he lost touch with American values while living in Paris, but his biographer Michael Reynolds claims the opposite, seeing evidence of the author's midwestern American values in the novel.  Hemingway admired hard work. He portrayed the matadors and the prostitutes, who work for a living, in a positive manner, but Brett, who prostitutes herself, is emblematic of "the rotten crowd" living on inherited money. It is Jake, the working journalist, who pays the bills again and again when those who can pay do not. Hemingway shows, through Jake's actions, his disapproval of the people who did not pay up.  Reynolds says that Hemingway shows the tragedy, not so much of the decadence of the Montparnasse crowd, but of the decline in American values of the period. As such, the author created an American hero who is impotent and powerless. Jake becomes the moral center of the story. He never considers himself part of the expatriate crowd because he is a working man; to Jake a working man is genuine and authentic, and those who do not work for a living spend their lives posing.

Women and love
The twice-divorced Brett Ashley represented the liberated New Woman (in the 1920s, divorces were common and easy to be had in Paris). James Nagel writes that, in Brett, Hemingway created one of the more fascinating women in 20th-century American literature. Sexually promiscuous, she is a denizen of Parisian nightlife and cafés. In Pamplona she sparks chaos: in her presence, the men drink too much and fight. She also seduces the young bullfighter Romero and becomes a Circe in the festival. Critics describe her variously as complicated, elusive, and enigmatic; Donald Daiker writes that Hemingway "treats her with a delicate balance of sympathy and antipathy." She is vulnerable, forgiving, independent—qualities that Hemingway juxtaposes with the other women in the book, who are either prostitutes or overbearing nags.

Nagel considers the novel a tragedy. Jake and Brett have a relationship that becomes destructive because their love cannot be consummated.  Conflict over Brett destroys Jake's friendship with Robert Cohn, and her behavior in Pamplona affects Jake's hard-won reputation among the Spaniards. Meyers sees Brett as a woman who wants sex without love while Jake can only give her love without sex.  Although Brett sleeps with many men, it is Jake she loves.  Dana Fore writes that Brett is willing to be with Jake in spite of his disability, in a "non-traditional erotic relationship."  Other critics such as Leslie Fiedler and Nina Baym see her as a supreme bitch; Fiedler sees Brett as one of the "outstanding examples of Hemingway's 'bitch women. Jake becomes bitter about their relationship, as when he says, "Send a girl off with a man .... Now go and bring her back. And sign the wire with love."

Critics interpret the Jake–Brett relationship in various ways.  Daiker suggests that Brett's behavior in Madrid—after Romero leaves and when Jake arrives at her summons—reflects her immorality. Scott Donaldson thinks Hemingway presents the Jake–Brett relationship in such a manner that Jake knew "that in having Brett for a friend 'he had been getting something for nothing' and that sooner or later he would have to pay the bill." Daiker notes that Brett relies on Jake to pay for her train fare from Madrid to San Sebastián, where she rejoins her fiancé Mike. In a piece Hemingway cut, he has Jake thinking, "you learned a lot about a woman by not sleeping with her." By the end of the novel, although Jake loves Brett, he appears to undergo a transformation in Madrid when he begins to distance himself from her. Reynolds believes that Jake represents the "everyman," and that in the course of the narrative he loses his honor, faith, and hope. He sees the novel as a morality play with Jake as the person who loses the most.

The corrida, the fiesta, and nature

In The Sun Also Rises, Hemingway contrasts Paris with Pamplona, and the frenzy of the fiesta with the tranquillity of the Spanish countryside.  Spain was Hemingway's favorite European country; he considered it a healthy place, and the only country "that hasn't been shot to pieces." He was profoundly affected by the spectacle of bullfighting, writing, It isn't just brutal like they always told us. It's a great tragedy—and the most beautiful thing I've ever seen and takes more guts and skill and guts again than anything possibly could. It's just like having a ringside seat at the war with nothing going to happen to you. He demonstrated what he considered the purity in the culture of bullfighting—called afición—and presented it as an authentic way of life, contrasted against the inauthenticity of the Parisian bohemians. To be accepted as an  aficionado was rare for a non-Spaniard; Jake goes through a difficult process to gain acceptance by the "fellowship of afición."

The Hemingway scholar Allen Josephs thinks the novel is centered on the corrida (the bullfighting), and how each character reacts to it. Brett seduces the young matador; Cohn fails to understand and expects to be bored; Jake understands fully because only he moves between the world of the inauthentic expatriates and the authentic Spaniards; the hotel keeper Montoya is the keeper of the faith; and Romero is the artist in the ring—he is both innocent and perfect, and the one who bravely faces death. The corrida is presented as an idealized drama in which the matador faces death, creating a moment of existentialism or nada (nothingness), broken when he vanquishes death by killing the bull.

Hemingway presents matadors as heroic characters dancing in a bullring. He considered the bullring as war with precise rules, in contrast to the messiness of the real war that he, and by extension Jake, experienced. Critic Keneth Kinnamon notes that young Romero is the novel's only honorable character.  Hemingway named Romero after Pedro Romero, an 18th-century bullfighter who killed thousands of bulls in the most difficult manner: having the bull impale itself on his sword as he stood perfectly still.  Reynolds says Romero, who symbolizes the classically pure matador, is the "one idealized figure in the novel."  Josephs says that when Hemingway changed Romero's name from Guerrita and imbued him with the characteristics of the historical Romero, he also changed the scene in which Romero kills a bull to one of recibiendo (receiving the bull) in homage to the historical namesake.

Before the group arrives in Pamplona, Jake and Bill take a fishing trip to the Irati River. As Harold Bloom points out, the scene serves as an interlude between the Paris and Pamplona sections, "an oasis that exists outside linear time."  On another level it reflects "the mainstream of American fiction beginning with the Pilgrims seeking refuge from English oppression"—the prominent theme in American literature of escaping into the wilderness, as seen in Cooper, Hawthorne, Melville, Twain, and Thoreau. Fiedler calls the theme "The Sacred Land"; he thinks the American West is evoked in The Sun Also Rises by the Pyrenees and given a symbolic nod with the name of the "Hotel Montana."  In Hemingway's writing, nature is a place of refuge and rebirth, according to Stoltzfus, where the hunter or fisherman gains a moment of transcendence at the moment the prey is killed. Nature is the place where men act without women: men fish, men hunt, men find redemption.  In nature Jake and Bill do not need to discuss the war because their war experience, paradoxically, is ever-present. The nature scenes serve as counterpoint to the fiesta scenes.

All of the characters drink heavily during the fiesta and generally throughout the novel. In his essay "Alcoholism in Hemingway's The Sun Also Rises", Matts Djos says the main characters exhibit alcoholic tendencies such as depression, anxiety and sexual inadequacy. He writes that Jake's self-pity is symptomatic of an alcoholic, as is Brett's out-of-control behavior. William Balassi thinks that Jake gets drunk to avoid his feelings for Brett, notably in the Madrid scenes at the end where he has three martinis before lunch and drinks three bottles of wine with lunch. Reynolds, however, believes the drinking is relevant as set against the historical context of Prohibition in the United States.  The atmosphere of the fiesta lends itself to drunkenness, but the degree of revelry among the Americans also reflects a reaction against Prohibition.  Bill, visiting from the US, drinks in Paris and in Spain. Jake is rarely drunk in Paris where he works but on vacation in Pamplona, he drinks constantly. Reynolds says that Prohibition split attitudes about morality, and in the novel Hemingway made clear his dislike of Prohibition.

Masculinity and gender
Critics have seen Jake as an ambiguous representative of Hemingway manliness. For example, in the bar scene in Paris, Jake is angry at some homosexual men. The critic Ira Elliot suggests that Hemingway viewed homosexuality as an inauthentic way of life, and that he aligns Jake with homosexual men because, like them, Jake does not have sex with women. Jake's anger shows his self-hatred at his inauthenticity and lack of masculinity. His sense of masculine identity is lost—he is less than a man. Elliot wonders if Jake's wound perhaps signifies latent homosexuality, rather than only a loss of masculinity; the emphasis in the novel, however, is on Jake's interest in women. Hemingway's writing has been called homophobic because of the language his characters use. For example, in the fishing scenes, Bill confesses his fondness for Jake but then goes on to say, "I couldn't tell you that in New York. It'd mean I was a faggot."

In contrast to Jake's troubled masculinity, Romero represents an ideal masculine identity grounded in self-assurance, bravery, competence, and uprightness. The Davidsons note that Brett is attracted to Romero for these reasons, and they speculate that Jake might be trying to undermine Romero's masculinity by bringing Brett to him and thus diminishing his ideal stature.

Critics have examined issues of gender misidentification that are prevalent in much of Hemingway's work. He was interested in cross-gender themes, as shown by his depictions of effeminate men and boyish women. In his fiction, a woman's hair is often symbolically important and used to denote gender. Brett, with her short hair, is androgynous and compared to a boy—yet the ambiguity lies in the fact that she is described as a "damned fine-looking woman." While Jake is attracted to this ambiguity, Romero is repulsed by it. In keeping with his strict moral code he wants a feminine partner and rejects Brett because, among other things, she will not grow her hair.

Antisemitism

Hemingway has been called antisemitic, most notably because of the characterization of Robert Cohn in the book. The other characters often refer to Cohn as a Jew, and once as a 'kike'. Shunned by the other members of the group, Cohn is characterized as "different", unable or unwilling to understand and participate in the fiesta. Cohn is never really part of the group—separated by his difference or his Jewish faith. Barry Gross, comparing Jewish characters in literature of the period, commented that "Hemingway never lets the reader forget that Cohn is a Jew, not an unattractive character who happens to be a Jew but a character who is unattractive because he is a Jew." Hemingway critic Josephine Knopf speculates that Hemingway might have wanted to depict Cohn as a "shlemiel" (or fool), but she points out that Cohn lacks the characteristics of a traditional shlemiel.

Cohn is based on Harold Loeb, a fellow writer who rivaled Hemingway for the affections of Duff, Lady Twysden (the real-life inspiration for Brett). Biographer Michael Reynolds writes that in 1925, Loeb should have declined Hemingway's invitation to join them in Pamplona. Before the trip he was Duff's lover and Hemingway's friend; during the fiasco of the fiesta, he lost Duff and Hemingway's friendship. Hemingway used Loeb as the basis of a character remembered chiefly as a "rich Jew."

Writing style
The novel is well known for its style, which is variously described as modern, hard-boiled, or understated. As a novice writer and journalist in Paris, Hemingway turned to Ezra Pound—who had a reputation as "an unofficial minister of culture who acted as mid-wife for new literary talent"—to mark and blue-ink his short stories.  From Pound, Hemingway learned to write in the modernist style: he used understatement, pared away sentimentalism, and presented images and scenes without explanations of meaning, most notably at the book's conclusion, in which multiple future possibilities are left for Brett and Jake. The scholar Anders Hallengren writes that because Hemingway learned from Pound to "distrust adjectives," he created a style "in accordance with the esthetics and ethics of raising the emotional temperature towards the level of universal truth by shutting the door on sentiment, on the subjective."

F. Scott Fitzgerald told Hemingway to "let the book's action play itself out among its characters." Hemingway scholar Linda Wagner-Martin writes that, in taking Fitzgerald's advice, Hemingway produced a novel without a central narrator: "Hemingway's book was a step ahead; it was the modernist novel." When Fitzgerald advised Hemingway to trim at least 2500 words from the opening sequence, which was 30 pages long, Hemingway wired the publishers telling them to cut the opening 30 pages altogether. The result was a novel without a focused starting point, which was seen as a modern perspective and critically well received.

Wagner-Martin speculates that Hemingway may have wanted to have a weak or negative hero as defined by Edith Wharton, but he had no experience creating a hero or protagonist.  At that point his fiction consisted of extremely short stories, not one of which featured a hero. The hero changed during the writing of The Sun Also Rises: first the matador was the hero, then Cohn was the hero, then Brett, and finally Hemingway realized "maybe there is not any hero at all. Maybe a story is better without any hero." Balassi believes that in eliminating other characters as the protagonist, Hemingway brought Jake indirectly into the role of the novel's hero.

As a roman à clef, the novel based its characters on living people, causing scandal in the expatriate community.  Hemingway biographer Carlos Baker writes that "word-of-mouth of the book" helped sales. Parisian expatriates gleefully tried to match the fictional characters to real identities.  Moreover, he writes that Hemingway used prototypes easily found in the Latin Quarter on which to base his characters. The early draft identified the characters by their living counterparts; Jake's character was called Hem, and Brett's was called Duff.

Although the novel is written in a journalistic style, Frederic Svoboda writes that the striking thing about the work is "how quickly it moves away from a simple recounting of events." Jackson Benson believes that Hemingway used autobiographical details as framing devices for life in general. For example, Benson says that Hemingway drew out his experiences with "what if" scenarios: "what if I were wounded in such a way that I could not sleep at night? What if I were wounded and made crazy, what would happen if I were sent back to the front?"  Hemingway believed that the writer could describe one thing while an entirely different thing occurs below the surface—an approach he called the iceberg theory, or the theory of omission.

Balassi says Hemingway applied the iceberg theory better in The Sun Also Rises than in any of his other works, by editing extraneous material or purposely leaving gaps in the story. He made editorial remarks in the manuscript that show he wanted to break from the stricture of Gertrude Stein's advice to use "clear restrained writing."  In the earliest draft, the novel begins in Pamplona, but Hemingway moved the opening setting to Paris because he thought the Montparnasse life was necessary as a counterpoint to the later action in Spain. He wrote of Paris extensively, intending "not to be limited by the literary theories of others, [but] to write in his own way, and possibly, to fail." He added metaphors for each character: Mike's money problems, Brett's association with the Circe myth, Robert's association with the segregated steer. It wasn't until the revision process that he pared down the story, taking out unnecessary explanations, minimizing descriptive passages, and stripping the dialogue, all of which created a "complex but tightly compressed story."

Hemingway said that he learned what he needed as a foundation for his writing from the style sheet for The Kansas City Star, where he worked as cub reporter.  The critic John Aldridge says that the minimalist style resulted from Hemingway's belief that to write authentically, each word had to be carefully chosen for its simplicity and authenticity and carry a great deal of weight. Aldridge writes that Hemingway's style "of a minimum of simple words that seemed to be squeezed onto the page against a great compulsion to be silent, creates the impression that those words—if only because there are so few of them—are sacramental." In Paris Hemingway had been experimenting with the prosody of the King James Bible, reading aloud with his friend John Dos Passos. From the style of the biblical text, he learned to build his prose incrementally; the action in the novel builds sentence by sentence, scene by scene and chapter by chapter.

The simplicity of his style is deceptive. Bloom writes that it is the effective use of parataxis that elevates Hemingway's prose. Drawing on the Bible, Walt Whitman and Adventures of Huckleberry Finn, Hemingway wrote in deliberate understatement and he heavily incorporated parataxis, which in some cases almost becomes cinematic. His skeletal sentences were crafted in response to Henry James's observation that World War I had "used up words," explains Hemingway scholar Zoe Trodd, who writes that his style is similar to a "multi-focal" photographic reality. The syntax, which lacks subordinating conjunctions, creates static sentences. The photographic "snapshot" style creates a collage of images. Hemingway omits internal punctuation (colons, semicolons, dashes, parentheses) in favor of short declarative sentences, which are meant to build, as events build, to create a sense of the whole. He also uses techniques analogous to cinema, such as cutting quickly from one scene to the next, or splicing one scene into another. Intentional omissions allow the reader to fill the gap as though responding to instructions from the author and create three-dimensional prose. Biographer James Mellow writes that the bullfighting scenes are presented with a crispness and clarity that evoke the sense of a newsreel.

Hemingway also uses color and visual art techniques to convey emotional range in his descriptions of the Irati River. In Translating Modernism: Fitzgerald and Hemingway, Ronald Berman compares Hemingway's treatment of landscape with that of the post-Impressionist painter Paul Cézanne. During a 1949 interview, Hemingway told Lillian Ross that he learned from Cézanne how to "make a landscape." In comparing writing to painting he told her, "This is what we try to do in writing, this and this, and woods, and the rocks we have to climb over." The landscape is seen subjectively—the viewpoint of the observer is paramount. To Jake, landscape "meant a search for a solid form .... not existentially present in [his] life in Paris."

Reception
Hemingway's first novel was arguably his best and most important and came to be seen as an iconic modernist novel, although Reynolds emphasizes that Hemingway was not philosophically a modernist. In the book, his characters epitomized the post-war expatriate generation for future generations. He had received good reviews for his volume of short stories, In Our Time, of which Edmund Wilson wrote, "Hemingway's prose was of the first distinction." Wilson's comments were enough to bring attention to the young writer.

Good reviews came in from many major publications. Conrad Aiken wrote in the New York Herald Tribune, "If there is a better dialogue to be written today I do not know where to find it"; and Bruce Barton wrote in The Atlantic that Hemingway "writes as if he had never read anybody's writing, as if he had fashioned the art of writing himself," and that the characters "are amazingly real and alive." Many reviewers, among them H.L. Mencken, praised Hemingway's style, use of understatement, and tight writing.

Other critics, however, disliked the novel. The Nation critic believed Hemingway's hard-boiled style was better suited to the short stories published in In Our Time than his novel. Writing in the New Masses, Hemingway's friend John Dos Passos asked: "What's the matter with American writing these days? .... The few unsad young men of this lost generation will have to look for another way of finding themselves than the one indicated here." Privately he wrote Hemingway an apology for the review. The reviewer for the Chicago Daily Tribune wrote of the novel, "The Sun Also Rises is the kind of book that makes this reviewer at least almost plain angry." Some reviewers disliked the characters, among them the reviewer for The Dial, who thought the characters were shallow and vapid; and The Nation and Atheneum deemed the characters boring and the novel unimportant. The reviewer for The Cincinnati Enquirer wrote of the book that it "begins nowhere and ends in nothing."

Hemingway's family hated it. His mother, Grace Hemingway, distressed that she could not face the criticism at her local book study class—where it was said that her son was "prostituting a great ability .... to the lowest uses"—expressed her displeasure in a letter to him:
The critics seem to be full of praise for your style and ability to draw word pictures but the decent ones always regret that you should use such great gifts in perpetuating the lives and habits of so degraded a strata of humanity .... It is a doubtful honor to produce one of the filthiest books of the year .... What is the matter? Have you ceased to be interested in nobility, honor and fineness in life? .... Surely you have other words in your vocabulary than "damn" and "bitch"—Every page fills me with a sick loathing.

Still, the book sold well, and young women began to emulate Brett while male students at Ivy League universities wanted to become "Hemingway heroes."  Scribner's encouraged the publicity and allowed Hemingway to "become a minor American phenomenon"—a celebrity to the point that his divorce from Richardson and marriage to Pfeiffer attracted media attention.

Reynolds believes The Sun Also Rises could have been written only circa 1925: it perfectly captured the period between World War I and the Great Depression, and immortalized a group of characters. In the years since its publication, the novel has been criticized for its antisemitism, as expressed in the characterization of Robert Cohn. Reynolds explains that although the publishers complained to Hemingway about his description of bulls, they allowed his use of Jewish epithets, which showed the degree to which antisemitism was accepted in the US after World War I. Hemingway clearly makes Cohn unlikeable not only as a character but as a character who is Jewish. Critics of the 1970s and 1980s considered Hemingway to be misogynistic and homophobic; by the 1990s his work, including The Sun Also Rises, began to receive critical reconsideration by female scholars.

Legacy and adaptations
Hemingway's work continued to be popular in the latter half of the century and after his suicide in 1961. During the 1970s, The Sun Also Rises appealed to what Beegel calls the lost generation of the Vietnam era.  Aldridge writes that The Sun Also Rises has kept its appeal because the novel is about being young. The characters live in the most beautiful city in the world, spend their days traveling, fishing, drinking, making love, and generally reveling in their youth. He believes the expatriate writers of the 1920s appeal for this reason, but that Hemingway was the most successful in capturing the time and the place in The Sun Also Rises.

Bloom says that some of the characters have not stood the test of time, writing that modern readers are uncomfortable with the antisemitic treatment of Cohn's character and the romanticization of a bullfighter. Moreover, Brett and Mike belong uniquely to the Jazz Age and do not translate to the modern era. Bloom believes the novel is in the canon of American literature for its formal qualities: its prose and style.

The novel made Hemingway famous, inspired young women across America to wear short hair and sweater sets like the heroine's—and to act like her too—and changed writing style in ways that could be seen in any American magazine published in the next twenty years. In many ways, the novel's stripped-down prose became a model for 20th-century American writing. Nagel writes that "The Sun Also Rises was a dramatic literary event and its effects have not diminished over the years."

The success of The Sun Also Rises led to interest from Broadway and Hollywood. In 1927 two Broadway producers wanted to adapt the story for the stage but made no immediate offers. Hemingway considered marketing the story directly to Hollywood, telling his editor Max Perkins that he would not sell it for less than $30,000—money he wanted his estranged wife Hadley Richardson to have. Conrad Aiken thought the book was perfect for a film adaptation solely on the strength of dialogue. Hemingway would not see a stage or film adaption anytime soon: he sold the film rights to RKO Pictures in 1932, but only in 1956 was the novel adapted to a film of the same name. Peter Viertel wrote the screenplay. Tyrone Power as Jake played the lead role opposite Ava Gardner as Brett and Errol Flynn as Mike. The royalties went to Richardson.

Hemingway wrote more books about bullfighting: Death in the Afternoon was published in 1932 and The Dangerous Summer was published posthumously in 1985. His depictions of Pamplona, beginning with The Sun Also Rises, helped to popularize the annual running of the bulls at the Festival of St. Fermin.

References

Citations

Sources

 Aldridge, John W. (1990). "Afterthought on the Twenties and The Sun Also Rises". in Wagner-Martin, Linda (ed). New Essays on Sun Also Rises. New York: Cambridge UP.
 Baker, Carlos (1972). Hemingway: The Writer as Artist. Princeton: Princeton UP.
 Baker, Carlos (1987). "The Wastelanders". in Bloom, Harold (ed). Modern Critical Interpretations: Ernest Hemingway's "The Sun Also Rises". New York: Chelsea House.
 Balassi, William (1990). "Hemingway's Greatest Iceberg: The Composition of The Sun Also Rises". in Barbour, James and Quirk, Tom (eds). Writing the American Classics. Chapel Hill: North Carolina UP.
 Baym, Nina (1990). "Actually I Felt Sorry for the Lion". in Benson, Jackson J. (ed). New Critical Approaches to the Short Stories of Ernest Hemingway. Durham: Duke UP.
 Beegel, Susan (1996). "Conclusion: The Critical Reputation". in Donaldson, Scott (ed). The Cambridge Companion to Ernest Hemingway. New York: Cambridge UP.
 Benson, Jackson (1989). "Ernest Hemingway: The Life as Fiction and the Fiction as Life". American Literature. 61 (3): 354–358
 Berman, Ronald (2011). Translating Modernism: Fitzgerald and Hemingway. Tuscaloosa: Alabama UP.
 Bloom, Harold (1987). "Introduction". in Bloom, Harold (ed). Modern Critical Interpretations: Ernest Hemingway's "The Sun Also Rises". New York: Chelsea House.
 Bloom, Harold (2007). "Introduction". in Bloom, Harold (ed). Ernest Hemingway's "The Sun Also Rises". New York: Infobase Publishing.
 Daiker, Donald (2009). "Lady Ashley, Pedro Romero and the Madrid Sequence of The Sun Also Rises". The Hemingway Review. 29 (1): 73–86
 Davidson, Cathy and Arnold (1990). "Decoding the Hemingway Hero in The Sun Also Rises". in Wagner-Martin, Linda (ed). New Essays on Sun Also Rises. New York: Cambridge UP.
 Djos, Matt (1995). "Alcoholism in Ernest Hemingway's The Sun Also Rises". The Hemingway Review. 14 (2): 64–78
 Donaldson, Scott (2002). "Hemingway's Morality of Compensation". in Wagner-Martin, Linda (ed). Ernest Hemingway's The Sun Also Rises: A Casebook. New York: Oxford UP.
 Elliot, Ira (1995). "Performance Art: Jake Barnes and Masculine Signification in The Sun Also Rises". American Literature. 63 (1): 77–94
 Fiedler, Leslie (1975). Love and Death in the American Novel. New York: Stein and Day.
 Fore, Dana (2007). "Life Unworthy of Life? Masculinity, Disability, and Guilt in The Sun Also Rises. The Hemingway Review. 16 (1): 75–88
 Hays, Peter L., ed. (2007). "Teaching Hemingway's The Sun Also Rises." Kent, OH: The Kent State University Press.
 Hemingway, Ernest (1926). The Sun Also Rises. New York: Scribner. 2006 edition.
 Herlihy-Mera, Jeffrey (2023). "The Sun Also Rises: A Pilgrimage Novel". The Hemingway Review. 42 (2): 25–55 https://www.academia.edu/101457931/
 Herlihy-Mera, Jeffrey (2012). "When Hemingway Hated Paris: Divorce Proceedings, Contemplations of Suicide, and the Deleted Chapters of The Sun Also Rises". Studies in the Novel. 44 (1): 49–61 https://www.academia.edu/1796661/
 Josephs, Allen (1987). "Torero: The Moral Axis of The Sun Also Rises". in Bloom, Harold (ed). Modern Critical Interpretations: Ernest Hemingway's "The Sun Also Rises". New York: Chelsea House.
 Kinnamon, Keneth (2002). "Hemingway, the Corrida, and Spain". in Wagner-Martin, Linda (ed). Ernest Hemingway's The Sun Also Rises: A Casebook. New York: Oxford UP.
 Knopf, Josephine (1987). "Meyer Wolfsheim and Robert Cohn: A Study of a Jew Type and Stereotype". in Bloom, Harold (ed). Modern Critical Interpretations: Ernest Hemingway's The Sun Also Rises". New York: Chelsea House.
 Leff, Leonard (1999). Hemingway and His Conspirators: Hollywood, Scribner's and the making of American Celebrity Culture. Lanham: Rowman & Littlefield.
 Mellow, James (1992). Hemingway: A Life Without Consequences. Boston: Houghton Mifflin.
 Meyers, Jeffrey (1985). Hemingway: A Biography. New York: Macmillan.
 Müller, Timo (2010). "The Uses of Authenticity: Hemingway and the Literary Field, 1926–1936". Journal of Modern Literature. 33 (1): 28–42
 Nagel, James (1996). "Brett and the Other Women in The Sun Also Rises". in Donaldson, Scott (ed). The Cambridge Companion to Ernest Hemingway. New York: Cambridge UP.
 Oliver, Charles (1999). Ernest Hemingway A to Z: The Essential Reference to the Life and Work. New York: Checkmark Publishing.
 Reynolds, Michael (1990). "Recovering the Historical Context". in Wagner-Martin, Linda (ed). New Essays on Sun Also Rises. New York: Cambridge UP.
 Reynolds, Michael (1999). Hemingway: The Final Years. New York: Norton.
 Reynolds, Michael (1989). Hemingway: The Paris Years. New York: Norton.
 Reynolds, Michael (1998). The Young Hemingway. New York: Norton.
 Stoltzfus, Ben (2005). "Sartre, "Nada," and Hemingway's African Stories". Comparative Literature Studies. 42 (3): 228–250
 Stoneback, H.R. (2007). "Reading Hemingway's The Sun Also Rises: Glossary and Commentary." Kent, OH: The Kent State UP.
 Svoboda, Frederic (1983). Hemingway & The Sun Also Rises: The Crafting of a Style. Lawrence: Kansas UP.
 Trodd, Zoe (2007). "Hemingway's Camera Eye: The Problems of Language and an Interwar Politics of Form". The Hemingway Review. 26 (2): 7–21
 Wagner-Martin, Linda (2002). "Introduction". in Wagner-Martin, Linda (ed). Ernest Hemingway's The Sun Also Rises: A Casebook. New York: Oxford UP.
 Wagner-Martin, Linda (1990). "Introduction". in Wagner-Martin, Linda (ed). New Essays on Sun Also Rises. New York: Cambridge UP.
 White, William (1969). The Merrill Studies in The Sun Also Rises. Columbus: C. E. Merrill.
 Young, Philip (1973). Ernest Hemingway. St. Paul: Minnesota UP.

External links

 Hemingway Archives, John F. Kennedy Library

1926 American novels
American autobiographical novels
American novels adapted into films
Bullfighting books
Charles Scribner's Sons books
1926 debut novels
Modernist novels
Novels by Ernest Hemingway
Novels set in France
Novels set in Paris
Novels set in Spain
Novels set in the Roaring Twenties
Roman à clef novels
Novels set in Madrid

The Sun Also Rises


In computer networking, the Name/Finger protocol and the Finger user information protocol are simple network protocols for the exchange of human-oriented status and user information.

Name/Finger protocol
The Name/Finger protocol is based on Request for Comments document RFC 742 (December 1977) as an interface to the name and finger programs that provide status reports on a particular computer system or a particular person at network sites. The finger program was written in 1971 by Les Earnest who created the program to solve the need of users who wanted information on other users of the network. Information on who is logged in was useful to check the availability of a person to meet. This was probably the earliest form of presence information for remote network users.

Prior to the finger program, the only way to get this information on WAITS was with a WHO program that showed IDs and terminal line numbers (the server's internal number of the communication line, over which the user's terminal is connected) for logged-in users. In reference to the name FINGER, Les Earnest, wrote that he saw users of the WAITS time-sharing system run their fingers down the output of the WHO command.

Finger user information protocol
The finger daemon runs on TCP port 79. The client will (in the case of remote hosts) open a connection to port 79. An RUIP (Remote User Information Program) is started on the remote end of the connection to process the request. The local host sends the RUIP one line query based upon the Finger query specification, and waits for the RUIP to respond. The RUIP receives and processes the query, returns an answer, then initiates the close of the connection. The local host receives the answer and the close signal, then proceeds to close its end of the connection.

The Finger user information protocol is based on RFC 1288 (The Finger User Information Protocol, December 1991). Typically the server side of the protocol is implemented by a program fingerd or in.fingerd (for finger daemon), while the client side is implemented by the name and finger programs which are supposed to return a friendly, human-oriented status report on either the system at the moment or a particular person in depth. There is no required format, and the protocol consists mostly of specifying a single command line.

The program would supply information such as whether a user is currently logged-on, e-mail address, full name etc.  As well as standard user information, finger displays the contents of the .project and .plan files in the user's home directory.  Often this file (maintained by the user) contains either useful information about the user's current activities, similar to micro-blogging, or alternatively all manner of humor.

Security concerns
Supplying such detailed information as e-mail addresses and full names was considered acceptable and convenient in the early days of networking, but later was considered questionable for privacy and security reasons.

Finger information has been used by hackers as a way to initiate a social engineering attack on a company's computer security system. By using a finger client to get a list of a company's employee names, email addresses, phone numbers, and so on, a hacker can call or email someone at a company requesting information while posing as another employee.

The finger daemon has also had several exploitable security holes crackers have used to break into systems. For example, in 1988 the Morris worm exploited an overflow vulnerability in fingerd (among others) to spread.

For these reasons, by the late 1990s the vast majority of sites on the Internet no longer offered the service.

Application support

It is implemented on Unix (like FreeBSD and macOS), Unix-like systems (like Linux), and current versions of Windows (finger.exe command). Other software has finger support:
ELinks
Lynx
Minuet
Kristall
Lagrange

See also
 LDAP
 Ph Protocol
 Social network service
 WebFinger

References

External links
 (December 1977)
 (December 1991)

Internet protocols
Internet Standards
OS/2 commands
Unix user management and support-related utilities
Unix network-related software
Windows administration
1977 software

Finger (protocol)


The executive is the branch of government that is responsible for the day-to-day management of the state. (Executive is short for executive branch or executive power.)

Under the doctrine of the separation of powers, the executive is not supposed to make laws (role of the legislature), nor to interpret them (role of the judiciary). The executive is supposed to put the laws into action.

The executive is led by the head of government. The head of government is assisted by a number of ministers, who usually have responsibilities for particular areas (e.g. health, education, foreign affairs), and by many government employees or civil servants.

In a presidential system, this person (the President) may also be the head of State, but in a parliamentary system, he or she is usually the leader of the largest party in the legislature and is most commonly termed the Prime Minister (Taoiseach in the Republic of Ireland, (Federal) Chancellor in Germany and Austria). In France, executive power is shared between the President and the Prime Minister and this system has been reproduced in a number of former French colonies. Switzerland and Bosnia and Herzegovina have similar systems.

Related pages
 Constitution
 Constitutional economics
 Political economy

Government-related organizations

Executive (government)


Fate or destiny is the idea that the future is already planned even if people do not know what their fate is (what is going to happen to them).  Humans in nearly all cultures have had ideas about their fate being "predetermined" (fixed in advance).

People who live unhappy lives may believe that their misery is because of their fate and that they can do nothing about it.  This is called being "fatalistic".  Other people may believe that they can control their fate by being brave and trying to "overcome"  fate by improving themselves and their lives.

In Greek mythology there were three Fates.  They were three goddesses who determined when every person was going to be born, how they would live and when and how they would die.  Human beings in many cultures had lots of ways in which they would try to "read" their fate (know what would happen to them).  Sometimes they would try to read their fate in the stars (this is called astrology).  In other cultures they might ask a person with powers of magic like a shaman.  The Ancient Greeks often went to Delphi to ask the oracle.

There are lots of references to fate in literature from almost every country and period, from Greek tragedy (e.g. Oedipus Rex) to Shakespeare (e.g. Macbeth) and Russian literature.

Composers may express fate in music.  Beethoven was thinking about Fate when he wrote his Fifth Symphony, and Tchaikovsky when he wrote his Sixth Symphony just before he committed suicide.

See also:
Ananke
Fatalism
Superstition
Moirae
Norns
Fate (opera)
Future

Fate


Doctrine (Latin: doctrina) is a code of beliefs or "a body of teachings".

Doctrine often means several religious dogmas that a church teaches.
But it can also mean a principle of law, in the common law traditions, established through a history of past decisions, such as the doctrine of self-defense, or the principle of fair use.

In matters of foreign policy, a doctrine, also known as dogma, is group of fundamental rules for a nation's foreign policy. Examples include the Monroe Doctrine, the Stimson Doctrine, the Truman Doctrine, the Eisenhower Doctrine, the Nixon Doctrine, the Brezhnev Doctrine, the Kirkpatrick doctrine, and the Bush Doctrine.

Religious usage

Examples of religious doctrines include:
 Christian Trinity and Virgin birth of Jesus
 Roman Catholic transubstantiation and immaculate conception
 Pentecostal Jesus-Only doctrine
 Calvinist predestination
 Methodist Prevenient Grace

One department of the Roman Curia is called the Congregation for the Doctrine of the Faith.

Military usage

The term also applies to the concept of an established procedure to a complex operation in warfare. The typical example is tactical doctrine in which a standard set of maneuvers, kinds of troops and weapons are employed as a default approach to a kind of attack.

Examples of military doctrines include:
 Blitzkrieg of World War II
 Hit-and-run tactics
 Shock and Awe
 Guerre de course
 Mahanian of late 19th up to mid-20th Century

Christian genres
Politics
Christian theology

Doctrine


The Hydrozoa are a class of the phylum Cnidaria. They are small predatory animals which mostly live in the sea. Their basic life form is the polyp. Some species live singly, others live in colonies. Their classification and evolutionary relationships are still under discussion. The hydroids may be best understood by taking some examples.

Hydra
The most widely-known freshwater hydrozoan is Hydra, which is found in slow-moving waters.

It is sessile, with a pedal disc which attaches it to substrate. Like all cnidarians, Hydra uses nematocysts, stinging cells which disable its prey. Hydra eat small crustaceans (such as brine shrimp), insect larvae, and annelid worms. It may reproduce sexually, or by asexual reproduction (budding).

Colonial types
The Portuguese Man o' War, Physalia physalis, is a large colonial marine jellyfish. It is composed of many tiny individual zooids, which are specialised polyps and medusae. The colony has an air bladder, and floats on the surface. It delivers a massive sting to its prey. Humans, if stung, may require medical attention. It is often accompanied by fish which are immune to the stings. This type of hydrozoan is called a siphonophore.

The chondrophores are another type of pelagic colonial hydrozoan. They are also carnivores, but their sting is not so harmful to humans.

Freshwater jellyfish
These have a muscular velum on the ventral surface, which allows them to move about. Beginning life as a tiny polyp, attached to vegetation, they feed and reproduce sexually in the spring and summer. If the habitat has only one sex, they reproduce by budding. They overwinter as resting bodies.

Taxonomy
Nowadays the Hydrozoa is split into two subclasses:
Leptolinae: the bulk of the hydroids and siphonophera
Trahylina: all others

Cnidarians

Hydrozoa


Birth control, also known as contraception or family planning, is a way for a man and woman to have sexual intercourse without the woman getting pregnant.

Some contraceptives, such as condoms, also protect a person from sexually transmitted diseases (STDs). When people use contraception to prevent STDs and pregnancy, it may be called safe sex.

Birth control is also sometimes called family planning. It means people can have babies or not as they wish. That way, babies and families do not happen by accident.

The need for birth control
Birth control lets a man and woman have sexual intercourse but makes pregnancy less likely.

During intercourse, a man places his penis in a woman's vagina and moves it in and out while the woman moves her hips. The vagina is warm and soft, and it places pressure on the man's penis. These sensations, combined with the in-and-out movements, stimulate the penis, which causes the man to have an orgasm. During orgasm, the man's penis spasms and experiences a series of rhythmic contractions during which he ejaculates (releases semen into the vagina). The semen can make the woman pregnant. Because intercourse is usually very enjoyable, men and women often want to have intercourse a lot more often than they want to have a baby. Birth control lets them have intercourse while greatly reducing the chances of the woman getting pregnant.

People may use birth control for several reasons. Perhaps a man and woman wish to have only a few children so they will have enough money to give those children good food, clothes, and education. More children might mean less for each child, so the parents use birth control to limit the number of children they have. Or maybe a man and woman do not want any children at all in order to focus on their own lives, jobs, or each other. Other couples may use birth control to make sure that they do not have too many children in too short a time, an idea that is called "spacing" their children. This may help them take better care of their children. Still another reason is that a young couple may not be able to afford having a baby until they are older and have more money or better jobs. This may be especially true of younger people who are still in school and probably not married. By using birth control, the couple can grow closer and strengthen their relationship by having sexual intercourse frequently so that when they are ready to have a baby their relationship is strong and stable. In most of these cases the man and woman want to have sex to be close, to feel good with each other, and to make their relationship stronger. Contraception lets them have intercourse while greatly reducing the chances of a pregnancy.

Birth control may be used by married couples, or by couples who live together but are not married, or by a man and woman who are engaged, or by a couple who are merely boyfriend and girlfriend, or even by single people who are not in a relationship at all but who may have casual sex with others.

Types of birth control
There are many types of birth control. Some of these have been done for a long time, but many of them were only discovered in the last eighty years. Each type of birth control has advantages and disadvantages. Another word for a type of contraception is a method.

Barrier methods
A barrier is something that stands between two things. So barrier methods stand between the sperm and the ovum (egg). Some barrier methods help prevent many sexually transmitted diseases (STDs):

 Condom – this is the oldest barrier method. A condom is a thin tube (often made of latex) that the man puts over his penis. This keeps the sperm from getting to the egg. Condoms are also called rubbers.
 Female condom – this is like a condom, but it goes in the woman's vagina.

Some barrier methods only protect a small amount against STDs:
 Diaphragm and cervical cap – these are objects that a woman puts in her vagina to cover the cervix (the opening at the bottom of the uterus where sperm get in).
 Contraceptive sponge – this is a sponge that is filled with spermicide (a substance that kills sperm) and is put in the woman's vagina over the cervix.

Barrier methods can be easy to use and have few side effects (bad things that happen if you take a medicine). Some of them can be bought without a doctor's prescription. Since they are easy to get and can help stop disease from spreading from one partner to the other, they are popular with younger couples or those who are early in a relationship. But sometimes they can be messy or interfere with the pleasure and sensation of sex.

Hormonal methods
These can only be used by women. Doctors are trying to find a way to use hormonal methods for men. Hormonal methods change the woman's reproductive cycle in different ways so that it is safe for her man to ejaculate inside her.

 Birth Control Pills – these are pills that a woman takes every day that make her stop ovulating (making eggs). They usually have both female hormones estrogen and progesterone in them. Some have only progesterone. Birth control pills are a very popular type of birth control because of how effective and easy to use they are. A woman who uses birth control pills is often said to be "on the Pill."
 Birth Control Patch – this is a small and thin object that is put on the woman's skin and stays there. Hormones in the patch go into the skin and into the woman's body. This makes her not ovulate.
 Emergency contraception pill – also called the morning-after pill. This is a medicine that is taken after sex that makes the woman less likely to get pregnant. It is best if used very soon after sex. The longer after sex it is taken, the less effective it is. It is recommended to be taken no more than 48 hours after the event. After this time, the pill no longer works well.
 Implants – these are objects that are put under the woman's skin and stay there for years. They slowly put hormones into her body and make her not ovulate. These only have progesterone in them (not estrogen).
 Injections (shots) – this is where a doctor or nurse gives the woman a shot with a needle every three to six months depending on the type of injection. They inject a progesterone hormone that makes the woman not ovulate.
 Rings - a soft plastic ring that is placed inside the vagina. The hormones in the ring go into the woman's vagina and into her body to prevent her from ovulating. The ring cannot be felt during sex and one ring lasts for up to three months.

Hormonal birth control is extremely effective if it is used in the right way. Many hormonal birth control methods also make women's menses shorter and with less bleeding, which most women like. And unlike barrier methods, hormonal methods do not interfere with sex. When a woman is using hormonal birth control, she and her man are usually not even aware of it during intercourse, which seems and feels very natural. The couple can have sex at any time they wish; they don't need to interrupt foreplay to put birth control in place, and they can feel the physical sensations and emotional closeness of intercourse without interference from a make or female condom. Unlike coitus interruptus (see below), when a woman is on the Pill or using some other form of hormonal birth control, intercourse usually ends with her man reaching orgasm while inside the vagina, which both the man and woman usually find very pleasurable. For all of these reasons, hormonal methods are very popular, especially with women who are married or in steady relationships who are having sex often.

Hormonal birth control methods have some slight risks for side effects. They may make a very small increase in the risk of blood clots in the lungs, strokes, heart attacks, and breast cancer. Most of these risk are small. Some women may experience mood swings, weight gain, or loss of sex drive. Sometimes, but rarely, these side effects are serious enough to make a woman decide to stop using hormonal birth control.

Intrauterine methods
This is where an object is put in the woman's uterus (womb, where the fetus grows when she is pregnant). This object is called an intrauterine device or IUD (acronym).

There are two types of IUD: the copper IUD or an IUD with hormones implanted on it. The hormonal IUD has better protection against pregnancy but costs more.

There are many good things about them:
 Do not need the woman to do anything after they are put in
 Last a long time (up to 10 years)
 Work very well at stopping pregnancy (98-99% of pregnancies are stopped)

The worst part about IUDs is that they have to be put in by a doctor. There is some risk of infection of the uterus after the IUD is put in, but this is only for 1-2 months after.

Copper IUDs can also be used as a day-after method to prevent pregnancy after the woman and man already had sex.

IUDs do not prevent STDs.

Sterilization
This is when a man or woman has surgery to make them not able to make babies.

Men can get a vasectomy. This is a small surgery where the tube that carries sperm from the testicles is cut.

Women can get tubal surgeries. These are ways that the fallopian tubes are cut or clipped so that eggs cannot go down them to the uterus. (The fallopian tube is the tube that carries the egg from the woman's ovary).

Sterilization is extremely effective, and they allow a man and woman to have intercourse that seems and feels very natural. But sterilization does involve surgery, which can cost more than other types of contraception and can be unpleasant, and unlike other methods it is very hard to reverse if a couple changes their minds and want to have children later.

Other surgeries will make a woman sterile (not able to get pregnant). These are not done only for contraception, but they are done for other reasons.
 Hysterectomy surgery to remove the uterus
 Oophorectomy surgery to remove the ovaries (both must be removed to make a woman sterile).

Traditional contraception

These have been used for a very long time. They were used before modern medicine. Some of them were used before scientists even discovered how reproduction (making babies) happens.
 Coitus interruptus (sometimes called "withdrawal" or "pulling out"– when the man takes his penis out of the woman's vagina before semen (liquid that has sperm in it) comes out. This is not a good method of birth control because the fluid that comes out before semen comes out also has sperm in it, and because if the man's semen is close to the woman's vagina, she can still get pregnant. Also, because the man's instinct is to stay inside the woman's vagina when he ejaculates, there is always a danger that he may not withdraw his penis in time. Even when it works, this can be a very frustrating method for both the man and woman because it interrupts their closeness and good feelings at the climax of intercourse.
 Non-penetrative sex, non-vaginal sex – sex without putting the man's penis in the woman's vagina. This is more effective than coitus interruptus, but it can still be risky if the man ejaculates on or near the woman, and it can also be frustrating for the couple not to be able to have intercourse.
 Abstinence – not having sex. If a couple can practice this correctly, it is completely effective at preventing pregnancy. It is free and does not require the help of a doctor. But it can be very frustrating for a man and woman to not be able to have intercourse.

Many methods can reduce the risk of STDs, but only abstinence is 100% effective.

Periodic abstinence
This means a man and a woman practice abstinence (not having sex) when the woman is fertile. When the woman is not fertile, she will not get pregnant when she has sex.
 Natural family planning: this is also called 'fertility awareness'. For this method, a woman reads her temperature (how warm her body is) in the morning, or she reads her cervical mucus (liquid that comes out of her vagina). Using the temperature or the cervical mucus, there are rules that say when the woman is fertile and not fertile.
 Billings ovulation method; Creighton model fertility care; two-day method; mucus-only method; basal body temperature method; sympto-thermo method: these are different names for natural family planning (see above).
 Rhythm method: this is where a woman records the number of days between her menses (the time when she bleeds). The woman is most likely to be fertile in the days right between her menses. For some women, the math does not work. They get pregnant when the math says they are less fertile.

Lactational Amenorrhea Method
This is when a woman is breastfeeding (using her breasts to make milk for her baby). There are certain rules the woman can use to know if she is not fertile. Chances that this method will fail are about 10% (which means 10% chance she can get pregnant)

Induced abortion
Induced abortion (sometimes called just abortion) is when a doctor gives a pregnant woman a medicine or does a surgery to stop the pregnancy. Some people do not call abortion a kind of contraception. This is because contraception means preventing pregnancy, but abortion is stopping a pregnancy that has already started.

Abortion is not a good birth control method. If a woman does not want to get pregnant, other methods are more safe and inexpensive (cost less money). So many doctors who do abortions for women help women find a better way to not get pregnant the next time.

Religion and contraception
Some religions do not like contraception. Some of them teach that contraception is a sin.

Religions ideas about contraception:
 Catholicism – almost all types of birth control are a sin (except Natural Family Planning or abstinence). The Catholic Church had no official policy over Contraception until 1930 when Pope Paul VI officially banned Catholics from using birth control pills, most forms of contraceptions, and even condoms. The Church believes sex is for a husband and wife to make a baby, and sex must always be open to life (possibility of making a new human) and contraceptions would be sinful as it blocks pregnancy even though the Bible does not ban contraceptions.
 Protestantism – most Protestant churches believe birth control is not a sin and allow couples to use it if they do not wish to make a baby.
 Islam – most schools of thought believe that some methods of birth control are not a sin. This is not applicable to sterilization, birth control due to financial hardship, or methods that deprive a woman of her right to sexual satisfaction.
 Judaism – there are many different beliefs in Judaism about birth control, but even the most conservative types of Judaism allow it if the woman will get sick if she gets pregnant.

Religious beliefs that contraception is a sin also keep people from doing safe sex. Some groups who are opposed to this belief say it is dangerous in places where there is a lot of HIV and AIDS, because condoms make people much less likely to get HIV, but at the same times many feel that they can practice extra marital sex since they are "safe" from HIV/AIDS.

Related pages
Marie Stopes
Margaret Sanger
Overpopulation
Reproductive rights

Other websites
These may be unsimple:

 Wedding Website: A simple introduction to cpntraception - in simple English
 University of California, Santa Barbara's SexInfo: Methods of Contraception For Men and Women
 World Health Organization information on family planning
 Planned Parenthood
 Medline Plus on birth control
 USFDA page "what kind of birth control is best for you?" in simpler English

Contraception
Feminism
Antinatalism

Birth control


The Global Biodiversity Information Facility (GBIF) is an international organisation that focuses on making scientific data on biodiversity available via the Internet using web services. The data are provided by many institutions from around the world; GBIF's information architecture makes these data accessible and searchable through a single portal. Data available through the GBIF portal are primarily distribution data on plants, animals, fungi, and microbes for the world, and scientific names data.

The mission of the GBIF is to facilitate free and open access to biodiversity data worldwide to underpin sustainable development. Priorities, with an emphasis on promoting participation and working through partners, include mobilising biodiversity data, developing protocols and standards to ensure scientific integrity and interoperability, building an informatics architecture to allow the interlinking of diverse data types from disparate sources, promoting capacity building and catalysing development of analytical tools for improved decision-making.

GBIF strives to form informatics linkages among digital data resources from across the spectrum of biological organisation, from genes to ecosystems, and to connect these to issues important to science, society and sustainability by using georeferencing and GIS tools. It works in partnership with other international organisations such as the Catalogue of Life partnership, Biodiversity Information Standards, the Consortium for the Barcode of Life (CBOL), the Encyclopedia of Life (EOL), and GEOSS. The biodiversity data available through the GBIF has increased by more than 1,150% in the past decade, partially due to the participation of citizen scientists.

From 2002 to 2014, GBIF awarded a prestigious annual global award in the area of biodiversity informatics, the Ebbe Nielsen Prize, valued at €30,000. , the GBIF Secretariat presents two annual prizes: the GBIF Ebbe Nielsen Challenge and the Young Researchers Award.

See also
 ABCD Schema
 Atlas of Living Australia (ALA)
 Australasian Virtual Herbarium (AVH)
 Darwin Core
 Global biodiversity
 List of electronic Floras (for other online flora databases)

References

External links

 Short description of GBIF
 GBIF network
 GBIF Data publishers

International environmental organizations
Biodiversity
Ecology organizations
Biodiversity databases
Online taxonomy databases
International organizations based in Denmark


Diabetes mellitus type 2 (or adult-onset diabetes) is a metabolic disorder where high levels of blood sugar  occur. Left untreated, it can cause heart attacks, strokes, blindness and kidney failure.

Cause
Usually, blood sugar levels are regulated by insulin, but in type 2 diabetes this does not work properly. Insulin is a hormone which tells the muscle and fat cells of the body to take up sugar from the blood. If there is too much sugar in the blood for a long period of time, the muscle and fat cells start to ignore insulin. As a result, sugar stays in the blood and is not taken up, leading to a high blood sugar.

This situation is different from diabetes mellitus type 1. In this case, the islet cells, which make insulin in the pancreas, have been destroyed by the body, and as a result there is no insulin. Diabetes type 1 usually occurs in children or young adults, whilst diabetes type 2 usually occurs in older people. However, recently childhood obesity has led to some young adults and teenagers developing type 2 diabetes. Type 2 diabetes makes up around 90% of cases of diabetes, while type 1 diabetes and other types of diabetes make up the other 10%.

Type 2 diabetes is a result of both genetics and lifestyle. People who have relatives with diabetes type 2 are at an increased risk. They may develop diabetes if they have other risk factors in their lifestyle, for example obesity, or low amount of exercise.

Complications
Poorly managed diabetes can lead to heart attacks, strokes, blindness and kidney failure.

Treatment
Type 2 diabetes can often be treated just by losing weight and exercising more, as these increase the body's sensitivity to insulin. A medicine called Metformin is often prescribed, which works by helping the fat and muscle cells of the body listen to the signal from insulin to take up sugar from the blood.

Reducing carbohydrate consumption could help with managing type 2 diabetes.

References

Diabetes mellitus

Type 2 diabetes


An ion is an electrically charged atom or molecule (group of atoms). It is "charged" so it will move near electricity. Atoms are made from positively charged protons, negatively charged electrons, and uncharged neutrons. Ions are charged because they have an unequal number of protons and electrons.

Making an ion from an atom or molecule is called ionization. Two or more ions can combine to make a chemical compound. The link between the ions is called an ionic bond.

The charge on a proton is chosen as +1 (positively charged). The charge on an electron is opposite to the charge on the proton.  The charge on the electron is -1 (negatively charged). An atom that is ionized makes two parts, one positive, and one negatively charged. For example, a neutral hydrogen atom has one proton and one electron. Ionizing the atom breaks it into two parts: (1) a positively charged hydrogen ion, H+ (2) a negatively charged electron.

A liquid with ions is called an electrolyte. A gas with lots of ions is called a plasma. When ions move, it is called electricity. For example, in a wire, the metal ions do not move, but the electrons move as electricity. A positive ion and a negative ion will move together. Two ions of the same charge will move apart. When ions move they also make magnetic fields.

Many ions are colourless. Elements in the main groups in the Periodic Table form colourless ions. Some ions are coloured. The transition metals usually form coloured ions.

Chemistry
In physics, atomic nuclei that have been completely ionized are called charged particles. These are ones in alpha radiation.

Ionization happens by giving atoms high energy. This is done using electrical voltage or by high-energy ionizing radiation or high temperature.

A simple ion is formed from a single atom.

Polyatomic ions are formed from a number of atoms. Polyatomic ions usually consist of all non-metal atoms. But sometimes the polyatomic ion can have a metallic atom too.

Positive ions are called cations. They are attracted to cathodes (negatively charged electrodes).  (Cation is pronounced "cat eye on", not "kay shun".) All simple metal ions are cations.

Negative ions are called anions. They are attracted to anodes (positively charged electrodes). All simple non-metal ions (except H+, which is a proton) are anions.

Transition metals can form more than one simple cation with different charges.

Most ions have a charge of less than 4, but some can have higher charges.

Michael Faraday was the first person to write a theory about ions, in 1830. In his theory, he said what the portions of molecules were like that moved to anions or cations. Svante August Arrhenius showed how this happened. He wrote this in his doctoral dissertation in 1884 (University of Uppsala). The university did not accept his theory at first (he only just passed his degree). But in 1903, he won the Nobel Prize in Chemistry for the same idea.

In Greek ion is like the word "go". "Anion" and "cation" mean "up-goer" and "down-goer". "Anode" and "cathode" are "way up" and "way down".

Common ions

References

Ion