Aarushhh/wikipedia-simple-splitted huggingface dataset:
Life

Family and early years
Wolfgang Amadeus Mozart ("Wolfi" or Wolferl") was born in Salzburg to Leopold and Anna Maria Mozart. Leopold was a violinist in the orchestra of the archbishop of Salzburg and the author of a best-selling introduction to playing the violin. 

Young Mozart showed evidence of great musical talent at a very early age. He was playing the harpsichord and the violin at the age of five, and writing little pieces of music.

Mozart's sister Maria Anna ("Nannerl") was a talented girl. The two children received their musical and academic education from their father. The family toured Europe for a few years, performing for royals and aristocrats.
Eventually, the Mozarts made their way back to Salzburg. But in 1768, they were off again to Vienna, where the now twelve-year-old Wolfgang staged a production of his ﬁrst opera, Bastien und Bastienne. And he was infected with smallpox at that time. He recovered but his face was pock-marked for life. He went to Italy where he heard music by many famous Italian composers, including Gregorio Allegri who had written a piece called Miserere. This piece had been written for the Pope for the choir of the Vatican to sing. No one was allowed to see the written music so that no other choir would be able to sing it. Mozart heard the piece once and then wrote it all down from memory. He met the Pope and was given a knighthood (Order of the Golden Spur).
In 1777, he went on a journey with his mother. In Mannheim, he fell in love with Aloysia Weber. She was 16 years old and studying singing. Mozart wanted to take her to Italy to make her famous, but his father put a stop to these plans. By 1778, Mozart and his mother were in Paris. His mother died there.

Mozart wrote some small operas when he was young, but his first really important opera was Idomeneo. It was first performed in Munich in 1780. The next year he went to Vienna. By this time he was working, like his father, for the Archbishop of Salzburg. When he went back to Salzburg he argued with the Archbishop who actually kicked him out. Mozart went off to Vienna where he would spend the rest of his life.
In 1782 he married Constanze Weber, one of the three younger sisters of Aloysia (who by now was married to someone else). They were to have seven children, but five of them died in childhood. Mozart’s father did not approve of the marriage. Constanze was a loving wife, but, like Mozart, she was not good at looking after money, so they were often very poor.

In that same year, 1782, Mozart wrote another very successful opera: Die Entführung aus dem Serail ("The Abduction from the Seraglio"). One famous story tells that, after the emperor had heard the opera, he told Mozart that there were “too many notes”. Mozart answered: “Just as many as are necessary, Your Majesty.”
Mozart started a series of concerts in which he played his own piano concertos, conducting from the keyboard. He met the composer Joseph Haydn and the two men became great friends, often playing together in a string quartet. Haydn said to Leopold Mozart one day: "Before God and as an honest man I tell you that your son is the greatest composer known to me either in person or by name. He has taste, and what is more, the most profound knowledge of composition." Mozart was in the same Masonic Lodge as Haydn, and he dedicated some of his string quartets to him.

The audiences in Vienna did not give Mozart much support after a few years, so he often went to Prague where the audiences loved him. His opera The Marriage of Figaro was very popular, and in 1787 he gave the first performance there of his opera Don Giovanni.
Illness and death 
There are several stories about Mozart’s last illness and death, and it is not easy to be sure what happened. He was working on an opera The Magic Flute which is one of his best works and a very popular opera today. It is written in German, not Italian, like most of his other operas. In some ways it is like an English pantomime. At the same time that he was working on this he was asked by a stranger to compose a requiem. He was told to write this in secret. Then he was asked to write an Italian opera La Clemenza di Tito, which was performed in Prague during September 1791. At the end of September The Magic Flute  was given its first performance. Mozart then worked very hard at the Requiem. He must have realized that he was already very ill, and that in a way the requiem (a mass for the dead) was for himself. He died in Vienna before he could finish it. Constanze asked another composer, a man called Franz Xaver Süssmayr, to finish the work. Mozart was buried in the St. Marx Cemetery.
Mozart’s music 
Mozart's music, like that of Haydn, is the very best of what is known as the Classical style. At the time he started to compose, the Baroque period was just coming to an end. Tastes were changing in music. Form, balance and elegance were thought of as more important than counterpoint. Mozart was the first great composer to write music for the piano, an instrument which had only just become popular. He wrote almost every kind of music: symphonies, operas, solo concertos, chamber music, especially string quartets and string quintets, and the piano sonata. He also wrote a lot of religious music, including masses, as well as popular music like dances, divertimenti and serenades.
When Mozart was young a symphony was usually a short, simple piece for entertainment. Mozart made the symphony into a carefully worked-out piece lasting up to half an hour. His last three symphonies are especially fine masterpieces. His concertos, especially his piano concertos, are far more advanced than anything that had been written before. Although Mozart behaved in truly childish ways at times, he was good at understanding human character. This is clear in his operas, where he introduced many subtle effects to describe the characters in the story.

Mozart's operas are among his greatest works.  He understood people's characters very well and was able to write music which tells us everything about the personalities in the operas.  The three operas in which he set words by Lorenzo Da Ponte: Don Giovanni, Le Nozze di Figaro (The Marriage of Figaro) and Cosi fan tutte each include some very clever ensembles in which several characters are singing at once, each one showing his or her view of the situation.
As well as many great masterpieces, Mozart wrote many pieces in a more popular style, including some tunes that everybody knows today. His serenade Eine kleine Nachtmusik K525 is known everywhere, as is the Turkish Rondo from his Piano Sonata in A K331, the opening of the Symphony No. 40 in G minor K550, and the birdcatcher’s song from The Magic Flute K620.

Regarding the instruments that Mozart was using for composing and performing, there was a number of them. In his early years he got to know pianos made by Franz Jakob Späth from Regensburg. Later in Augsburg Mozart got impressed by pianos from Stein. After moving to Vienna the composer purchased an instrument by Walter.
Catalogue of works 
Some time after Mozart’s death a man called Köchel studied all Mozart’s music, tried to put them in chronological order, and gave them a number. The number helps us to know exactly which work is meant, for example Symphony in G minor K183 is not the same piece as Symphony in G minor K550 (K stands for Köchel. Sometimes it is written "KV550" standing for "Köchel Verzeichnis" i.e. "Köchel Catalogue"). The highest Köchel number is 626, his requiem mass.

Related pages
 Amadeus (movie)

References 

Groves Dictionary of Music and Musicians, edited by Stanley Sadie; 1980; 
Listening To Western Music, written by Craig Wright; ISBN 978-0-495-11627-1

Other websites 

 The Mozart Project 
 Mozart livecams Live pictures of Mozart Birth house, Mozart Monument, Mozart lives on View and so on.

1756 births
1791 deaths
Austrian composers
Child prodigies
Classical era composers
People from Salzburg
Smallpox survivors
Austrian Roman Catholics
Wolfgang Amadeus
Johann Sebastian Bach (31 March 1685 in Eisenach – 28 July 1750 in Leipzig; pronounced BAHK) was a German composer and organist. He lived in the last part of the Baroque period. He is most famous for his work Toccata and Fugue in D Minor, St. Matthew Passion, St. John Passion, Mass in B minor, and the Brandenburg Concertos. He spent several years working at courts of noblemen. Here he wrote most of his chamber music and orchestral music. Most of his life, however, he worked in a church where he was expected to write church music. Bach wrote almost every kind of music except opera. During the last part of his life most composers were writing in a new style called the Classical style, but Bach always wrote in the Baroque style. That made some people at the time think he was old-fashioned, but today we know that his work is the very best of Baroque music.  Along with Mozart and Beethoven, Bach is regarded as one of the greatest composers who has ever lived.
Early life
Bach came from a highly musical family. His father, Johann Ambrosius Bach, was a trumpeter at the court of Saxe-Eisenach. Many of his relatives were professional musicians of some sort: violinists and town musicians, organists, Cantors (Directors of Music in a church), court musicians and Kapellmeisters (Directors of Music at a royal court). Most of them played several instruments. Of his twenty children, several became quite famous composers, especially Carl Philipp Emanuel Bach (1714–1788), Johann Christian Bach (1735–1782), Johann Christoph Friedrich Bach and Wilhelm Friedemann Bach (1710–1784).
When he was fifteen, he went to the small town of Lüneburg. At first he sang treble in the choir and was said to have a very fine treble voice, but his voice very soon got lower, so he made himself useful playing instruments. He learned by listening to famous organists like Reincken (1623–1722) and Dietrich Buxtehude (1637–1707). Bach got his first job in 1703 in Arnstadt. It was a well-paid job for a young boy who was 18 years old. There was a new organ in the church, and Bach already knew a lot about organ building as well as being a brilliant organist. They asked him to examine the new organ, and then they offered him a job. Bach spent four years as organist there. He composed some organ works. Unfortunately, the congregation were not musical enough to like it. They did not understand the ornamental notes he added to the hymn tunes. Bach got rather fed up with the priests who were always complaining about it, so he resigned and took another job in Mühlhausen, not far away
. After a year there, he gave up that job and went to a big town called Weimar.
Weimar years (1708–1717) 

Johann Sebastian was made organist to the Duke of Saxe-Weimar. At the Duke’s court there was a chapel with an organ. Bach composed many of his great organ works at this time. He became very famous as an organist and was invited to play in other big churches and to give advice on organ building. He was extremely good at improvisation. On one occasion he was in Dresden at the same time as a French organist named Louis Marchant. There was going to be a competition between the two men to see who was better at improvisation. Bach was practicing the day before and Marchant heard him. He realized that Bach would win, so he left.
In 1714 the Duke made Bach Konzertmeister (Concertmaster, a job that paid more money). He had to write cantatas for church services. In 1717 he was offered a job in the town of Cöthen, where he would earn an even better salary. The Duke was angry and did not want him to go but Bach insisted, so the Duke put Bach in prison for a month. In the end he had to let the musician go.

Cöthen (1717–1723)
At Cöthen, Bach worked for Prince Leopold. The Prince was very musical and a wonderful man to work for. Bach was Kapellmeister (Director of Music) and was treated well. The organ was not very good, and it was not used much, so Bach did not write any organ music during this period. The Duke had an orchestra, and Bach was in charge. Nearly all Bach’s orchestral works were written in Cöthen: the Brandenburg Concertos, the violin concertos, the orchestral suites, the solo music for violin and for cello, and a lot of keyboard music for harpsichord or clavichord.
During 1719, the great composer George Frideric Handel, who had moved to England, came to Germany to visit his mother. Bach wanted to meet Handel, who was only 30 km away, but these two famous musicians never met. Handel wanted to spend his limited time in Germany with his mother who was old and frail, knowing that it would be the last time he would see her.

Bach’s first wife, Maria Barbara Bach, died in 1720. The couple had seven children. Soon afterwards, he married Anna Magdalena with whom he had another thirteen children. However, several of his children died young.
In 1723 Bach moved to Leipzig to take the job of Cantor at the St Thomas Church, a very large church in the town. As Cantor he was in charge of all the music, both at St Thomas and at another church nearby. He also had to compose music for the town. It was an excellent job, and more secure than being at a court. The schools were good for his sons. Bach stayed in Leipzig until his death. He loved his job most of the time and worked very hard. He composed many cantatas for the church services. These services were very long, lasting about three hours. Many of the cantatas he wrote last about 30 minutes. He had assistants to play the organ. Bach himself directed the choir and the orchestra. There were probably 16 singers in the choir and 18 players in the orchestra. He wrote the St Matthew Passion and the St John Passion. Both these works, which are very long, tell the story of Jesus dying on the cross. They are among the most famous pieces of music ever written
. He also wrote cantatas for special occasions such as weddings or funerals.
Life was not always easy, and sometimes there were arguments with the people who ruled the church. The sub-deacon wanted to choose some of the hymns, but this was the Cantor’s job. Bach was a sensible man, and he managed to get his way without making enemies. On another occasion he argued with the headmaster of the school (Bach had to do some teaching at the church school) about who was allowed to choose the choir section leaders. This actually went to court, and Bach won the case.

Bach often made journeys to other towns. In 1747 he visited the court of Prussian King Frederick the Great near Berlin. The king, a music lover, gave Bach a theme to improvise from on the harpsichord. Bach sat down and improvised a fugue using this theme. Later Bach wrote a very long composition for flute, violin and harpsichord with cello accompaniment, in many movements, all based on this theme. At the end, the theme is heard in 5 of the 6 voices. Bach called it The Musical Offering and he sent it to the king.
Bach wrote many fugues, eventually he decided to write a collection called The Art of Fugue. His plan was to publish it, but he died before he could finish it (his son later published it in his honor, as Bach's last published piece). In the last year or two of his life, he became blind in spite of two eye operations.
In the 19th century more people became interested in Bach, and many of his works were published after he had been dead more than a hundred years.

Discography
Studio albums
 Magnificat BWV 243 / Cantata "Ich habe genug" BWV 82 (1995)
 Brandenburg Concertos nos. 1 - 6 (1997)
 Die Kunst der Fuge BWV 1080 (2001)
 Oboe Concertos (2005)
 Goldberg-Variationen: Fassung für zwei Klaviere von Joseph Rheinberger und Max Reger (2009)

References

Other websites

 The JS Bach Home Page-Part of joint Bach website project
 J.S. Bach Archive and Bibliography-Part of joint Bach website project 
 The DigitalBach Project at the Oregon Bach Festival
1685 births
1750 deaths
Johann Sebastian
Baroque composers
18th-century German composers
German Lutherans
German organists
People from Saxony-Anhalt
German harpsichordists
The Earth's atmosphere is the layer of gasses around the Earth. It is held in place by Earth's gravity. It is today  made up mainly of nitrogen (78.1%). It also has plentiful oxygen (20.9%) and small amounts of argon (0.9%), carbon dioxide (~ 0.035%), water vapor, and other gases. The atmosphere protects life on Earth by absorbing (taking) ultraviolet rays from the Sun. It makes our days cooler and our nights warmer.

Solid particulates, including ash, dust, volcanic ash, etc. are small parts of atmosphere. They are important in making clouds and fog.

The atmosphere does not end at a specific place. The higher above the Earth, the thinner the atmosphere. There is no clear border between the atmosphere and outer space, though the Kármán line is sometimes treated as a border. Even higher, for some purposes the edge of the magnetosphere is treated as a border. 75% of the atmosphere is within  of the Earth's surface.
History of Earth's atmosphere 
The most important thing to remember about the Earth and other planets is that they do not come from the Sun. They or their materials were picked up by the Sun's gravitation as it moved through space. The Sun is just composed of hydrogen, with a little bit of helium. Nothing else. The material which makes up planets and their satellites is almost entirely heavier elements whose origin was in earlier supernovae explosions. The planets do give off small quantities of hydrogen and helium: this comes from the decay of larger radioactive molecules whose origin is also ancient supernovae.
Originally, the Earth's atmosphere had almost no free oxygen.
The first atmosphere consisted of gases in the solar nebula, mainly hydrogen. There might also have been simple hydrides such as those now found in the gas giants (Jupiter and Saturn): water vapor, methane and ammonia. 
The atmosphere gradually changed to mostly carbon dioxide and nitrogen. The lighter gases, like hydrogen and helium, cannot be held by the Earth's gravity, and would escape. For a long time (say two billion years or more), the atmosphere was dominated by carbon dioxide.
In the Great Oxygenation Event the atmosphere changed to the kind we have now, with oxygen replacing the carbon dioxide. Our atmosphere is still mostly nitrogen, but most living organisms interact more with oxygen than with nitrogen. Oxygenation began with cyanobacteria making free oxygen by photosynthesis. Most organisms today need oxygen for their respiration: only a few anaerobic organisms can grow without oxygen.

Temperature and the atmospheric layers
These are the layers of the atmosphere, starting from the ground:
Troposphere - Starts at the ground. Ends somewhere between . The higher, the colder. Weather in this layer affects our daily life.
Stratosphere - Starts at . Ends at . The higher, the hotter. The heat comes from the Ozone layer at the top of the stratosphere. There is little water vapor and other substances in this layer. Airplanes fly in this layer because it is usually stable and air resistance is small.
Mesosphere - Starts at . Ends at . The higher, the colder. Winds in this layer are strong, so the temperature is not stable.
Thermosphere - Starts at . Ends at  or higher. The higher, the hotter. This layer is very important in radio communication because it helps to reflect some radio waves.
Exosphere - Above the thermosphere. This is the top layer, and merges into interplanetary space.
Regions where one layer changes to the next have been named "-pauses." So the tropopause is where the troposphere ends ( high). The stratopause is at the end of the stratosphere. The mesopause is at the end of the mesosphere. 
These are boundaries.

The average temperature of the atmosphere at the surface of Earth is .

Pressure 
The atmosphere has pressure. This is because even though air is a gas, it has weight. The average atmospheric pressure at sea level is about .

Density and mass
The density of air at sea level is about 1.2 kilograms per cubic meter.  This density becomes less at higher altitudes at the same rate that pressure becomes less. The total mass of the atmosphere is about 5.1 × 1018 kg, which is only a very small part of the Earth's total mass.

Related pages 
 Air
 Life timeline

References

Other websites 
The Atmosphere

Atmosphere
Earth
Meteorology
The human penis is a male body part found on the outside of the body. It is used for urination and for sexual intercourse. The main sexual function of the penis is to be inserted into a female's vagina and deliver semen which may cause pregnancy. The penis also provides pleasure during other types of sexual activity, including foreplay, oral sex, and solo sex (which doctors say is normal and healthy.)

There are many slang words for penis. They include dick, cock, and schlong. A euphemism for penis is male member. The general area where the penis is located is called the crotch. Sometimes people who do not want to use the word penis use the word crotch instead. For example, someone might say a rapper "grabbed his crotch" rather than "grabbed his penis."
Females have a clitoris, which is like a penis, although the outside part of the clitoris is much smaller than the penis. Most of the clitoris is inside the body. Part of the shaft of the clitoris is covered by a thin layer of skin called the clitoral hood, which is similar to the foreskin of the penis, discussed below. Both the penis and the clitoris are erectile organs, meaning they can become larger and harder when touched, rubbed, or stimulated in other ways.

Structure
Structure 

The human penis exits the abdomen above the scrotum and hangs freely outside the body. The main visible part is called the shaft.
The human penis has three parts.
Body of the penis: The main visible part of the penis. The urethra runs underside of the penis.
Root of the penis: Invisible part of the penis. It reaches near the anus and contains the bulb of the penis and the crus of the penis. The crus of the penis is attached to the pubic bone.
Skin of the penis: The shaft is covered by the skin. The skin is not attached tightly to the inner tissue. So it can move freely on the shaft.
The human penis is made up of three rod-shaped tissues. It has two corpora cavernosa (special pieces of muscle) next to each other and a corpus spongiosum (spongy muscle) between them.
The end of the corpus spongiosum forms the glans penis. The glans penis is covered by the foreskin in uncircumcised males. The rounded base of the glans is called the corona. The area on the bottom of the penis, where the foreskin is attached, is known as the frenulum of prepuce. 

The urethra, the tube where urine and semen travel through, runs down the corpus spongiosum (spongy tissue), and opens at the tip of the penis. The opening is called the urinary meatus. Sperm are made in the testes (ball-like organs) and stored in the epididymis (layer of tissue) around the testes. During ejaculation, sperm are pushed up the vas deferens. Fluids are added by the seminal vesicles, the prostate gland and the bulbourethral glands to make semen.

In sexual reproduction

Erection
A penis can become erect ("hard") if a  male is sexually aroused (or sometimes during sleep, even though there is no sexual stimulation). In an erection, the penis fills with blood. The blood makes the penis become longer, thicker and harder. Veins taking blood away from the penis get smaller, so less blood is taken through. Arteries bringing blood to the penis get wider, bringing more blood to the penis. Erections sometimes occur in the male fetus (before birth), and occur naturally from birth onwards.  It is normal for the penis to be erect when a male wakes up. This is commonly called morning wood. It is also normal for male teenagers and men to have an erection several times per night when sleeping. If this does not happen, the person may have a bad medical problem or depression (a mental health problem.) Not being able to have an erection can also be caused by various common drugs, including antidepressants and drugs taken to control high blood pressure
. During the day, an erection sometimes happens for no reason, or when undressing. This is most common in young teenagers and is normal.  People call this a spontaneous (sudden or surprise) erection. A slang word for an erection is a boner.
Ejaculation 

Ejaculation is when semen is pushed from the penis. It usually happens during an orgasm. Males can ejaculate during sexual intercourse or by masturbation. There are usually 40 million or more sperm in the semen ejaculated. Semen usually has a slight smell of chlorine and ammonia. It is not poisonous, but it is very bad if it gets in someone's eye. The enzymes semen contains to penetrate the egg in a female will also attack the eye. Be careful not to ejaculate into your eye or your partner's eye. Semen contains proteins and fructose (a kind of sugar.) Some people say it tastes sweeter if the man eats a lot of fruit. Scientists have not proven that. Smoking, or drinking coffee, tea or colas that contain caffeine can create a bitter flavor. Semen is slimy when wet. Eventually, it dries in the air and hardens like glue.
Orgasm and ejaculation can happen during many types of sex acts including anal and oral sex, and when masturbating. A condom should be used during anal sex to avoid getting a urinary tract infection. Masturbation can include touching and rubbing the penis and other sensitive areas of the body, such as the scrotum, and other places in the genital area. This can be done naked or through clothes. Sometimes the penis is squeezed between the partner's thighs without being inserted into the body. This is called intercrural sex. Sometimes the penis is rubbed against the other person's body. The people can be naked or wearing clothes. When two males rub their penises together or against each other's body, it is called frottage. Ejaculation may also happen without touching during sleep (called a 'wet dream'). This is common, especially for pre-teen and teenage boys. It is uncommon in adults. While it can feel almost magical to ejaculate during a dream, boys don't like the mess it creates
. Boys usually don't have wet dreams if they masturbate before sleeping every night.  A male must have started puberty before he can ejaculate. (Sometimes when a boy who has not started puberty masturbates, a small amount of urine comes out.) During orgasm, muscles push semen from the penis. Semen moves through the urethra and comes out of the hole at the tip of the penis.
Condom use 

A man can put a condom on his penis to prevent semen from entering the female's reproductive system. A condom is very thin, so having sex still feels good. It is normally made of latex. If used correctly, a condom usually stops the woman from getting pregnant and having a baby. The condom also lowers the chance of getting a sexually transmitted infection from the sexual partner or giving a sexually transmitted infection to the sexual partner. While condoms are most commonly used during vaginal sex, a condom can also be used during oral sex, anal sex, and masturbation.
Vaccination to reduce the spread of sexually transmitted infections 
Vaccinating young people (both girls and boys) before the age when they first have sex can reduce their risk of getting one infection called HPV. The United States CDC says the HPV vaccine should be given at age 11 or 12 years but can be started at age 9. HPV increases the risk of cancer, including cancer in the throat or neck if people have oral sex (licking, kissing or sucking on the penis.) HPV can be under the foreskin if the penis has a foreskin, and in the semen whether the penis is circumcised or uncircumcised.

Penis size in humans
The length and thickness of the penis is different for different people. The size of a soft penis (flaccid or not erect) is much smaller than when it is erect. Some penises grow more when they get hard than other penises. In most cases, whether a penis is big or small, it can still be used for sex. It averages out to be around 3 to 6 inches long when not erect. The average size of an erect human penis is between 13 – 16 cm (5.1– 6 in). The average circumference of a penis is 12.3 cm (4.85 in) when fully erect. The penis grows bigger during puberty. At the start of puberty, the average length of the penis is . The penis reaches adult size about 5 years later. A study done in 1996 found the mean length of an adult man's penis is  when it is not erect. The average length of an erect penis is about .
The human penis is longer than in other primates except for the chimpanzee. The chimpanzee's penis is about the same length. The penis is bigger in circumference on humans than on other primates.
The foreskin is a fold of skin that covers the end of the penis. The foreskin is a bit thicker than an eyelid. Cutting off the foreskin is called circumcision. The foreskin is connected to the head of the penis. During circumcision, most or all of the foreskin is removed from the penis. This simple change to the penis is very common in many countries of the world including the United States and Israel.  Circumcision is done for medical reasons because it lowers the chance of ever getting cancer of the penis to near zero. The foreskin removed during circumcision is a possible source of penile cancer. Childhood circumcision has a strong protective effect against penile cancer in later life. Penile cancer has been nearly eliminated in populations of males circumcised shortly after birth. Circumcision virtually eliminates the risk of invasive penile cancer. Being uncircumcised is a risk factor for penile cancer. Invasive penile cancer is cancer that spreads in the body
. It is uncommon but often causes the man to die. Circumcision also reduces the risk of cancer of the cervix in female sexual partners.  Cervical cancer is very common. It causes over 300,000 deaths of women worldwide every year. Circumcision reduces, but does not eliminate, the risk of getting or spreading HIV/AIDS. Circumcision became more common in Africa after HIV/AIDS began. The use of condoms also reduces the risk of getting or spreading HIV/AIDS, but many people in Africa cannot afford condoms or choose not to use them.
Circumcision is usually performed on infant males for medical reasons, or for religious reasons, especially for Jews and Muslims, or cultural reasons in the United States, the Philippines, and South Korea. "Cultural reasons" means reasons such as beliefs that the penis stays cleaner or looks more beautiful when circumcised. "Cultural reasons" also includes tradition, meaning parents wanting their son's penis to look like the father's penis and like other boys' penises. In the United States, one of the reasons for it being a tradition is that it was once a requirement in the navy and popular in other parts of the military. The World Health Organization estimates that the overall male circumcision rate in the United States is somewhere between 76 and 92 percent. Circumcision was also very common in Canada, although that is no longer the case, due in part to changes in government rules about paying for circumcision
. Through the first half of the twentieth century, up to about the late 1960s and even the early 1970s, it was common for men in the United States and Canada to swim naked (without bathing suits) at high school, college, and YMCA pools. It was also common that men showered together in schools and in the military. Since it was common for boys and young men to be naked, many parents wanted their sons to look like other American males. Parents did not want their sons to look different from the majority.
Some males have the foreskin cut off when they are adults because they have problems with their foreskin. Some males have the foreskin cut off because they want to change how their penis looks. Few boys are born without a foreskin or with a very short foreskin, called aposthia, naturally circumcised. 

In common speech, you can say that someone is cut or uncut, meaning circumcised or not circumcised. For example, one teenage boy might ask another teenage boy, "Are you cut?" While this is slang English, it is not considered profanity.
In some religions, babies and young boys have their foreskins cut off. This is expected in Islam and Judaism. It is not required according to Christianity. Among Christians in the United States, it is more common among Protestants than among Catholics. In the United States, circumcision is less common among boys and men whose families came from Mexico, who are usually Catholic. In Judaism, infant males are required to have their foreskin removed as a sign of the covenant (ancient promise) made with God.

When a foreskin is removed from a baby, doctors can use the skin for important medical purposes. Doctors can replace skin on someone with burns or with foot sores caused by diabetes. Foreskins that have been removed can be used for medical research.
If a male is uncut (uncircumcised) he should wash under the foreskin every day. However, young boys should not pull or push their foreskin back when washing. Not washing can cause a bad smell. People should not use soap when washing their penis. Getting soap inside the penis (in the urethra) can hurt. It is like getting soap in the eyes.

Skin color
Penile skin is often slightly darker than skin in surrounding areas. This is due to a higher concentration of melanocytes in genital skin tissue. The tip (glans) of the penis is usually pink or red color even if the penis shaft skin is dark. If the man is not circumcised, the tip is usually covered by the foreskin. The foreskin is about the same color as the skin on the shaft of the penis.
If a man's penis skin changes color and he doesn't know why, he should go to a doctor. He could have an infection, diabetes or cancer. A sunburn on the penis can happen quickly.  If a man is outside without clothes, he will get a sun tan. That is normal. Too much sun causes sunburn. Doctors say to use sunscreen (sun cream) before and after nude swimming. A sunburn can happen in a few minutes on a very sunny day.

Culture
 
Since the oldest cultures the penis has assumed a strong importance as a symbol of fertility used also in religious ceremonies to celebrate and (people hoped) to improve the reproductive capacity of men and beasts. For example, in Roman paganism, the god Priapus is characterized by a huge penis. In some places in Japan and South Korea, there are special days and public events to celebrate the penis. When an erect penis is shown in art or in cultural events, it is often called a phallus.
Piercing 
Some men put jewelry on their penis. This is a type of body piercing called genital piercing. One main reason is that it can make sex more pleasurable. Jewelry is sometimes at the tip (through the glans and urethra), sometimes through the foreskin, corona, or frenulum, or sometimes under the shaft of the penis.

Related pages 
 Male reproductive system
 Phallus
 Scrotum
 Testicles
 Vagina
 Fellatio

References

Other websites 

 Kinsey Institute on the penis  

Anatomy of the male reproductive system
The Sahara, in North Africa, is the largest desert in the world except for Antarctica. The Sahara is the largest hot desert.

It is bounded by the Atlantic Ocean, the Atlas Mountains, the Mediterranean Sea, the Red Sea, and the Sahel region. It runs through many countries including Morocco, Algeria, Tunisia, Libya, Egypt, Mauritania, Mali, Niger, Chad, and The Sudan. Most parts are uninhabited, but some people manage to survive in places where there is water.

The Sahara Desert is about 9,000,000 square kilometers (3.5 million square miles) in size. It has been both larger and smaller at different times. After the last ice age it became more fertile, then dried up again. It is the hottest place on the Earth, but not the driest. The driest is the Atacama Desert in South America. The Sahara has about the same size as the whole United States.
Climate 
The Sahara has one of the world's most harsh climates. Typically, the Sahara landscape experiences little rainfall, powerful winds and wide temperature ranges. In some areas, there can be no rainfall for years at a time.

In the summer, daytime air temperatures across the Sahara often reach over 100 degrees Fahrenheit. In the winter the freezing temperatures may occur in the northern Sahara, and milder temperatures, across the southern Sahara. Snow may fall occasionally in some of the higher mountain ranges and rarely, on the desert floor.

Environment 
The highest mountain is 3415 m, and is the Emi Koussi in Chad. Some mountain peaks in the Sahara Desert have snow even in the summer. The main mountain ranges is the Atlas Mountains in Algeria. The Sahara's lowest point lies in the Qattara Depression in Egypt, at about 130 metres below sea level. Sand sheets and dunes are about 25% of the Sahara. The other parts are mountains, steppes with a lot of stones, and oases.
Several rivers run through the Sahara. However, most of them come and go through the seasons, except for the Nile River and Niger River.

Metallic minerals are very important to most Saharan countries. Algeria and Mauritania have several major deposits of iron ore.  There are also uranium mines, mostly in Niger.  A lot of phosphates are in Morocco and Western Sahara.  Petroleum is mainly found in Algeria, where it is very important to the economy.  While mineral exploitation has led to economic growth in Sahara, this has rarely helped the indigenous population, as skilled workers have been brought from other countries.

Cities 
Of the Sahara's around 4 million people, most live in Mauritania, Western Sahara, Algeria, Libya and Egypt.  Dominant groups of people are Sahrawis and Tuareg people.  The largest city is Nouakchott, Mauritania's capital.  Other important cities are Tamanrasset in Algeria, and Sebha and Ghat in Libya.
Only 200,000 km² of the Sahara are fertile oases, where dates, corn, and fruits are grown. The few fertile regions today are fed by underground rivers and underground basins. Many of Sahara's oases rests in depressions (areas under sea level) allowing water to surface from underground reservoirs; artesian wells.

The soil in Sahara is low in organic matter. The soil in depressions is often saline.

Other sorts of vegetation include scattered concentrations of grasses, shrubs and trees in the highlands, as well as in the oases and along river beds. Some plants are well adjusted to the climate, allowing them to germinate within 3 days of rain and sow their seeds within 2 weeks after that.
Animals living in the Sahara include gerbil, jerboa, cape hare and desert hedgehog, barbary sheep, oryx, gazelle, deer, wild ass, baboon, hyena, jackal, sand fox, weasel and mongoose. The bird life counts more than 300 species. Reptiles, including 4 species of snake also live here.  The most venomous scorpion in the world lives here.

4,000 years ago, the Sahara was a thriving savanna grassland with a great variety of wildlife.  This included animals such as elephants and giraffes.  Climate change has caused the rainfall to be less and turn the Sahara into the barren, desert wilderness as we know it today.

References

Other websites 
 Flora and fauna of the Sahara  

Deserts of Africa
Paris (nicknamed the "City of light") is the capital city of France, and the largest city in France. The area is , and around 2.15 million people live there. If suburbs are counted, the population of the Paris area rises to 10.7 million people. It is the most densely populated city in the European Union, with  20.653 people per square kilometer.

The Seine river runs through the oldest part of Paris, and divides it into two parts, known as the Left Bank and the Right Bank. It is surrounded by many forests.

Paris is also the center of French economy, politics, traffic and culture. Paris has many art museums and historical buildings. As a traffic center, Paris has a very good underground subway system (called the Metro). It also has two airports. The Metro was built in 1900, and its total length is more than .
The city has a multi-cultural style, because 19% of the people there are from outside France. There are many different restaurants with all kinds of food. Paris also has some types of pollution like air pollution and light pollution.

History 
Julius Caesar conquered the Celtic "Parisii" tribe in 51 BC. The largest clan of French people in Paris is Parisii in 2023. The Romans called the place Lutetia of the Parisii, or "Lutetia Parisiorum". The place got a shorter name, "Paris", in 212 AD.
As the Roman Empire began to fall apart in the West, the Germanic tribe called the Franks moved in, taking it in 464. In 507, their king Clovis I made it his capital. Charlemagne moved his capital to Aachen in Germany, but Paris continued as an important town and was attacked by the Vikings twice. When Hugh Capet became king of France in 987, he again made Paris his capital. For a long time, the kings only controlled Paris and the surrounding area, as much of the rest of France was in the hands of barons or English. During the Hundred Years' War, the English controlled Paris from 1420 to 1437.

During the Protestant Reformation, a huge massacre of French Protestants started there in 1572, called the Saint Bartholomew Day Massacre. Paris saw many other troubles over the years of the "Ancien Régime" (Old Kingdom), then in 1789, the French Revolution began in Paris, leading to more massacres.
Paris was the Capital of the French Empire which, as well as France, covered Spain, Belgium, Holland, Luxembourg, Switzerland, Italy, most of Germany and some of Austria, Croatia, Slovenia and Poland. The Empire ruled by Napoleon was from 1804 to 1814/1815. The Russian army seized Paris from Napoleon in 1814, and the Prussian army captured it in 1871. The next time it was captured was by the Nazi Germans in 1940. The Allies freed the city in 1944 and it has not since been captured.

Also, the city has been featured in many songs including the #1 hit song by Jay-Z and Kanye West called "Niggas in Paris".

Climate 
Paris has an oceanic climate in the Köppen climate classification. It has warm summers and cold winters, and rainfall year-round.

Tourism 
Paris has much to offer for sightseeing. Here are five very famous examples:
The Eiffel Tower is the most famous sight in Paris, built by Gustave Eiffel in 1889 with  of iron — that means 18,000 pieces of iron and 2.5 million rivets. With a height of 300 meters, for a long time it was the highest tower in the world. Over 6 million people visit it every year. There are three levels that you can visit, and the highest one is 2nd above the ground. It was made for a fair, but the French government wanted to tear it down. With rising popularity, it stayed.
 The Louvre is a museum with very famous, old works of art, such as the Mona Lisa and the Venus de Milo. The building was built as a house for French kings. The Louvre is the third biggest museum in the world, with  of show room. It is the most visited art museum in the world with over 5 million people visit it each year.
 The Musée d'Orsay was a train station, but it is now an art museum. Most of the art at the Musée D'Orsay was made between 1848 and 1915. This is newer than the art at the Louvre.
The Moulin Rouge is a cabaret with many shows, and it opened in 1889. It is in Montmartre — a part of Paris with an exciting nightlife. In the Moulin Rouge, women put on a famous dance called the French cancan.
  The Champs-Élysées is probably the most famous street in Paris, and one of the most famous in the world. It is full of places to shop and eat. On one end of the Champs-Élysées is the Arc de Triomphe.
 The Notre Dame de Paris is a major Gothic cathedral, which was destroyed on 15 April 2019. It is in "Île de la Cité".
 The Basilica of Sacré-Coeur is a major church devoted to the Sacred Heart.
Transportation 
Because the city of Paris is roughly only 10 kilometres/6 miles across, visitors have a wide range of options when it comes to transportation. While much of the more well-known attractions are in the center of the city and are best experienced by walking, there are many destinations that require other means of transport. While taxis offer a fast and relatively inexpensive means of travel, Paris’ public transportation system offers an enjoyable, stress-free way to explore the city.
The Paris Métro system was built in 1900 by engineer Fulgence Bienvenüe and architect Hector Guimard. The Métro covers over 198 kilometers/124 miles with 300 stations and 16 lines. Servicing over 6 million residents and tourists every day, the Métro was designed to be an efficient and reliable alternative to the congestion of traffic. Every building in Paris is less than 500 meters from a train station, so accessibility is never a problem. The 16 Métro lines are identified by their final destinations. A rider can simply select the appropriate line and take it in the direction s/he wants. The Métro stations are well marked, and there are ticket booths at most entrances.

There are five airports that serve Paris: Charles de Gaulle Airport, Orly Airport, Beauvais-Tillé Airport and Paris–Le Bourget Airport, and Châlons Vatry Airport.
Events 
 1900 – The 2nd Summer Olympic Games took place in Paris.
 1924 – The 8th Summer Olympic Games took place in Paris.
 1998 – The FIFA World Cup
 2024 – The 33rd Summer Olympic Games will take place in Paris.

Related pages 
 Cataphile
 Capital of France

References

Other websites 

 Official website of the Paris Convention and Visitors Bureau (English version)
 This city at the Historical Association for Joan of Arc Studies
 Visiting Paris – tips and useful advice
 RATP
 Navigating the Paris Métro

 
Capital of France
Olympic cities
The Holocaust, sometimes called The Shoah (), was a genocide in which Nazi Germany systematically killed mainly Jews during World War II.  six million Jews were killed, as well as five million others that the Nazis claimed were inferior (mainly Slavs, communists, Roma people, disabled people, homosexuals, and Jehovah's Witnesses). These people were rounded up, put in ghettos, forced to work in concentration camps, and then killed in gas chambers.

Why were the Jews killed?

There was hatred and persecution of Jews (Anti-Semitism) in Europe for hundreds of years. Many people wrongly thought that all Jews became rich by stealing money from other people, such as Christians; that they did not like people other than their fellow Jews; and that they harmed children to use their blood for religious rituals (blood libel). These beliefs were not true and were based on stereotypes and prejudices.

However, these beliefs were popular in the German-speaking world and elsewhere in the late 1800s.
Adolf Hitler was born in Austria during this time, when many people disliked Jews. He may have been jealous of Jewish success in Austria. However, in a book he wrote called Mein Kampf ("My Struggle"), he said it was the Jews' fault that Germany and Austria lost World War I. He also wrote that Germany's economic problems were the Jews' fault. Many people agreed with Hitler’s ideas and supported him as the leader of the Nazi Party.

Deaths 

Not all deaths were written down, so the exact numbers are unknown. However, various sources approximate:

 Jews (5.1–6 million killed), including:
 Polish Jews (3 million killed);
 Ethnic Poles (1.8-2 million killed);
 Roma and Sinti (200,000–800,000 killed);
 Disabled people (200,000–250,000 killed);
 Homosexuals (22,000–25,000 killed);
 Jehovah's Witnesses (950–2500 killed).
Led by Hitler, the Nazis killed millions of Jews. They forced Jews to wear the golden Star of David on their upper bodies. Jews were rounded up by the thousands and crammed into trains that took them to concentration camps like Auschwitz as well as death camps. Most of the Jews killed in the Holocaust were not German. They were from Poland or the Soviet Union.

The Nazis killed millions of people, hundreds at a time, with poison gas in special rooms called gas chambers. They forced others to dig giant holes in the ground where, after days of hard work, Jews and other prisoners were shot, buried, and burned in a mass grave. The Nazis executed many others by shooting, stabbing, or beating them to death. Many also died in forced marches from one camp to another. Other causes of death include starvation, diseases, and freezing to death because of the terrible conditions in the concentration camps.