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1 | april (apr.) is the fourth month of the year in the julian and gregorian calendars, and comes between march and may. it is one of the four months to have 30 days.
april always begins on the same day of the week as july, and additionally, january in leap years. april always ends on the same day of the week as december.
the month
april comes between march and may, making it the fourth month of the year. it also comes first in the year out of the four months that have 30 days, as june, september and november are later in the year.
april begins on the same day of the week as july every year and on the same day of the week as january in leap years. april ends on the same day of the week as december every year, as each other's last days are exactly 35 weeks (245 days) apart.
in common years, april starts on the same day of the week as october of the previous year, and in leap years, may of the previous year. in common years, april finishes on the same day of the week as july of the previous year, and in leap years, february and october of the previous year. in common years immediately after other common years, april starts on the same day of the week as january of the previous year, and in leap years and years immediately after that, april finishes on the same day of the week as january of the previous year.
in years immediately before common years, april starts on the same day of the week as september and december of the following year, and in years immediately before leap years, june of the following year. in years immediately before common years, april finishes on the same day of the week as september of the following year, and in years immediately before leap years, march and june of the following year.
april is a spring month in the northern hemisphere and an autumn/fall month in the southern hemisphere. in each hemisphere, it is the seasonal equivalent of october in the other.
it is unclear as to where april got its name. a common theory is that it comes from the latin word "aperire", meaning "to open", referring to flowers opening in spring. another theory is that the name could come from aphrodite, the greek goddess of love. it was originally the second month in the old roman calendar, before the start of the new year was put to january 1.
quite a few festivals are held in this month. in many southeast asian cultures, new year is celebrated in this month (including songkran). in western christianity, easter can be celebrated on a sunday between march 22 and april 25. in orthodox christianity, it can fall between april 4 and may 8. at the end of the month, central and northern european cultures celebrate walpurgis night on april 30, marking the transition from winter into summer.
april in poetry
poets use april to mean the end of winter. for example: april showers bring may flowers.
events in april
fixed events
april 1 - april fools' day
april 1 - islamic republic day (iran)
april 2 - international children's book day
april 2 - thai heritage and conservation day
april 2 - world autism awareness day
april 2 - malvinas day (argentina)
april 4 - independence day (senegal)
april 4 - international day for landmine awareness and assistance
april 4 - peace day (angola)
april 5 - end of tax year (united kingdom)
april 6 - tartan day (canada and united states)
april 6 - chakri day (thailand)
april 7 - day of maternity and beauty (armenia)
april 7 - genocide memorial day (rwanda)
april 7 - world health day | 1,024 | 0 |
1 | april (apr.) is the fourth month of the year in the julian and [...]
april 7 - women's day (mozambique)
april 8 - buddha's birthday (buddhism)
april 9 - martyrs' day (tunisia)
april 9 - day of national unity (georgia)
april 9 - day of the finnish language
april 12 - cosmonauts' day (russia), marking the day of yuri gagarin's space flight
april 13 - songkan (laos), local new year celebration
april 13 - cambodian new year
april 13 - thomas jefferson's birthday (united states)
april 14 - southeast asian new year festivals, including songkran
april 14 - georgian language day
april 14 - youth day (angola)
april 14 - ambedkar jayanti (india)
april 14 - pan-american day
april 15 - tax day (united states)
april 15 - kim il-sung's birthday (north korea)
april 15 - father damien day (hawaii)
april 15 - jackie robinson day (major league baseball)
april 16 - birthday of queen margrethe ii of denmark
april 16 - emancipation day (washington, dc)
april 16 - world voice day
april 16 - selena day (texas)
april 17 - national day of syria
april 17 - flag day (american samoa)
april 17 - women's day (gabon)
april 17 - world hemophilia day
april 18 - independence day (zimbabwe)
april 18 - invention day (japan)
april 18 - international day of monuments and sites
april 19 - bicycle day
april 19 - dutch-american friendship day
april 19 - birthday of king mswati iii of swaziland
april 19 - patriots' day (massachusetts, maine, wisconsin)
april 20 - 4/20 in cannabis culture
april 21 - john muir day (california)
april 21 - san jacinto day (texas)
april 21 - kartini day (indonesia)
april 21 - national tree planting day (kenya)
april 21 - first day of ridran (baha'i faith)
april 21 - grounation day (rastafari movement)
april 22 - earth day
april 22 - discovery day (brazil)
april 23 - saint george's day, celebrating the patron saint of several countries, regions and cities (including england and catalonia)
april 23 - world book day
april 23 - national sovereignty and children's day (turkey)
april 24 - democracy day (nepal)
april 24 - genocide day (armenia)
april 24 - republic day (the gambia)
april 25 - australia and new zealand celebrate anzac day. anzac means australian and new zealand army corps, and began in 1915.
april 25 - world dna day
april 25 - world malaria day
april 25 - flag day (swaziland, faroe islands)
april 25 - freedom day (portugal)
april 25 - liberation day (italy)
april 25 - army day (north korea)
april 26 | 1,024 | 27 |
1 | april (apr.) is the fourth month of the year in the julian and [...] - union day (tanzania)
april 26 - confederate memorial day (texas, florida)
april 27 - independence day (sierra leone and togo)
april 27 - freedom day (south africa)
april 27 - world tapir day
april 27 - king's day (netherlands) from 2014, birthday of willem-alexander of the netherlands
april 28 - workers memorial day
april 28 - national day (sardinia)
april 28 - national heroes day (barbados)
april 29 - showa day (japan), birthday of emperor hirohito, who died in 1989
april 29 - international dance day
april 30 - former queen's day holiday in the netherlands (changed to king's day, april 27 in 2014), was the birthday of former queen juliana of the netherlands
april 30 - flag day in sweden (birthday of king carl xvi gustaf of sweden)
april 30 - international jazz day
april 30 - walpurgis night (central and northern europe)
moveable events
easter-related events in western christianity:
palm sunday (between march 15 and april 18)
maundy thursday (between march 19 and april 22)
good friday (between march 20 and april 23)
easter sunday (between march 22 and april 25)
easter monday (between march 23 and april 26)
eastern orthodox easter falls between april 4 and may 8.
ascension day (western christianity), falls between april 30 and june 3.
jewish passover - falls in the same week as western christianity's holy week, which is the week leading up to easter.
mother's day (uk) falls between march 1 and april 4.
world snooker championship (late april, early may)
horse racing - grand national (uk), kentucky derby (united states)
start of daylight saving time - clocks going forward one hour:
most of mexico
morocco (ramadan does not include daylight saving time)
end of daylight saving time - clocks going back one hour:
southeast australia, and new zealand
chile
marathon events in the following cities:
belgrade, serbia
boston, massachusetts, united states
brighton, united kingdom
enschede, netherlands
london, united kingdom (held in october from 2020 to 2022 because of covid-19)
madrid, spain
paris, france
rotterdam, netherlands
utrecht, netherlands
zurich, switzerland
selection of historical events
april 1, 1918 - the royal air force is founded.
april 1, 1976 - apple inc. is founded.
april 1, 1979 - the islamic republic of iran is founded.
april 1, 1999 - the territory of nunavut is created in northern canada.
april 1, 2001 - the netherlands introduces same-sex marriage, as the first country to do so.
april 2, 1519 - florida is sighted by a european for the first time.
april 2, 1930 - haile selassie becomes emperor of ethiopia.
april 2, 1982 - start of the falklands war, as argentine forces land on the falkland islands.
april | 1,024 | 27 |
1 | april (apr.) is the fourth month of the year in the julian and [...] 2, 2005 - pope john paul ii dies aged 84, after years as pope.
april 3, 1973 - the first-ever mobile phone call is placed by martin cooper in new york city.
april 4, 1721 - robert walpole becomes the first prime minister of great britain.
april 4, 1841 - william henry harrison dies. he was president of the united states for 31 days, the shortest-ever time in office for a us president.
april 4, 1960 - senegal becomes independent.
april 4, 1968 - assassination of martin luther king, jr. in memphis, tennessee.
april 5, 1722 - jacob roggeveen becomes the first european to land on easter island, landing there on easter sunday.
april 6, 1320 - scotland's independence is confirmed with the declaration of arbroath.
april 6, 1830 - the mormon church is founded.
april 6, 1909 - robert peary claims to have been first at the north pole on this date.
april 7, 1994 - the rwandan genocide begins.
april 9, 1865 - american civil war: confederate forces under robert e. lee surrender to union forces.
april 9, 1940 - world war ii: denmark and norway are invaded by nazi germany.
april 9, 1989 - april 9 tragedy: in tbilisi, georgia, a peaceful demonstration for independence is broken up by the soviet army, killing 20 people. the country gains independence on this date exactly two years later.
april 10, 1815 - mount tambora in indonesia erupts in a huge eruption, affecting the world's climate for at least a year.
april 10, 2010 - a plane crash near smolensk, russia, kills several people who were important in poland, including president lech kaczynski.
april 11, 1814 - napoleon bonaparte is exiled to the island of elba.
april 11, 1954 - said to have been the most boring day of the 20th century.
april 12, 1861 - the american civil war begins at fort sumter, charleston, south carolina.
april 12, 1945 - us president franklin d. roosevelt dies, and harry s. truman replaces him.
april 12, 1961 - yuri gagarin becomes the first human to fly into space.
april 14, 1865 - us president abraham lincoln is shot dead at ford's theatre by john wilkes booth. lincoln dies the next day.
april 14, 2010 - qinghai province, china, is hit by an earthquake, killing tens of thousands of people.
april 14, 2010 - the eruption of eyjafjallajokull in iceland shuts down air traffic around europe for a week, due to its ash cloud.
april 15, 1912 - the ship rms titanic sinks near newfoundland after hitting an iceberg, resulting in the deaths of many of the people on board.
april 16, 1943 - albert hofmann discovers lsd's effects.
april 17, 1946 - syria gains full independence from france.
april 17, 1955 - albert einstein dies.
april 18, 190 | 1,024 | 27 |
1 | april (apr.) is the fourth month of the year in the julian and [...] 6 - 1906 san francisco earthquake: san francisco, california, is hit by a big earthquake, resulting in fires that destroy large parts of the city.
april 18, 1980 - zimbabwe gains full independence.
april 19, 1897 - the first boston marathon is held.
april 19, 1971 - sierra leone becomes a republic.
april 19, 1993 - the siege of the branch davidians at waco, texas, ends in a fire that kills 82 people.
april 19, 1995 - timothy mcveigh carries out the oklahoma city bombing, killing 169 people.
april 19, 2005 - joseph alois ratzinger becomes pope benedict xvi.
april 20, 1889 - adolf hitler is born.
april 20, 1902 - marie curie and pierre curie refine radium.
april 20, 2010 - deepwater horizon oil spill: a massive fire on the deepwater horizon drilling rig in the gulf of mexico kills 11 workers and causes a massive oil spill, the worst spill in us history.
april 21, 753 bc - legendary founding date of rome
april 21, 1509 - henry viii of england becomes king.
april 21, 1908 - frederick cook claims to have reached the north pole on this date.
april 22, 1502 - pedro alvares cabral becomes the first european to reach present-day brazil.
april 22, 1970 - earth day is observed for the first time.
april 23, 1533 - the church of england declares that henry viii of england and catherine of aragon are not married.
april 24, 1916 - the easter rising occurs in dublin, ireland.
april 24, 1990 - the hubble space telescope is launched on the space shuttle discovery.
april 25, 1915 - world war i: in turkey, the battle of gallipoli begins, australian, french, british and new zealand forces land at anzac cove.
april 25, 1974 - portugal's dictatorship is overthrown in a coup, in what is known as the carnation revolution.
april 26, 1937 - spanish civil war: german planes bomb the town of guernica, basque country, later depicted in a painting by pablo picasso.
april 26, 1964 - tanganyika and zanzibar merge to form tanzania.
april 26, 1986 - a reactor explosion occurs at the chernobyl nuclear plant in present-day ukraine, with radiation spreading around europe and the world.
april 26/27, 1994 - south africa holds its first free elections.
april 27, 1960 - togo becomes independent from france.
april 27, 1961 - sierra leone becomes independent from the united kingdom.
april 28, 1789 - mutiny on the ship bounty in the pacific ocean, lead by fletcher christian.
april 28, 1945 - benito mussolini is executed by italian partisans.
april 28, 1947 - in peru, thor heyerdahl starts his kon-tiki expedition aimed at proving his theory that the polynesian settlers on the pacific ocean | 1,024 | 27 |
1 | april (apr.) is the fourth month of the year in the julian and [...]'s islands came from south america.
april 29, 1991 - a cyclone in bangladesh kills an estimated 138,000 people.
april 29, 2011 - the wedding of prince william, duke of cambridge and catherine, duchess of cambridge is broadcast worldwide.
april 30, 1789 - george washington becomes the first president of the united states.
april 30, 1803 - the united states purchases (buys) the louisiana territory from france.
april 30, 1945 - adolf hitler commits suicide on the same day that the soviet army raises the red flag on berlin's reichstag.
april 30, 1952 - the diary of anne frank is published in english.
april 30, 1975 - the vietnam war ends, as north vietnamese forces take saigon.
april 30, 1980 - queen juliana of the netherlands abdicates the throne, and her daughter becomes queen beatrix of the netherlands. beatrix later also abdicates, on this day in 2013, in favor of her son, king willem-alexander of the netherlands.
trivia
april has the 100th day of the year. april 10 in a common year, april 9 in a leap year.
in western christianity, easter falls more often in april than in march.
the months around april (march and may) both start with an'm' in the english language, with an 'a' as the second letter.
in the english language, april is the first of three months in-a-row, along with may and june, that is also a female given name.
the astrological signs for april are aries (march 21 to april 20) and taurus (april 21 to may 20).
the sweet pea and daisy are the traditional birth flowers for april.
the birthstone for april is the diamond.
april 1 is the only day in april to start within the first quarter of the calendar year.
if the months of the year were arranged in alphabetical order in the english language, april would come first.
five current european monarchs were born in april. they are king philippe of belgium (april 15), queen margrethe ii of denmark (april 16), henri, grand duke of luxembourg (april 16), king willem-alexander of the netherlands (april 27), and king carl xvi gustaf of sweden (april 30). elizabeth ii of the united kingdom and commonwealth realms - who died on september 8, 2022 - was also born in april (on april 21).
04 | 801 | 27 |
2 | august (aug.) is the eighth month of the year in the gregorian calendar, coming between july and september. it has 31 days. it is named after the roman emperor augustus caesar.
august does not begin on the same day of the week as any other month in common years, but begins on the same day of the week as february in leap years. august always ends on the same day of the week as november.
the month
this month was first called sextilis in latin, because it was the sixth month in the old roman calendar. the roman calendar began in march about 735 bc with romulus. october was the eighth month. august was the eighth month when january or february were added to the start of the year by king numa pompilius about 700 bc. or, when those two months were moved from the end to the beginning of the year by the decemvirs about 450 bc (roman writers disagree). in 153 bc january 1 was determined as the beginning of the year.
august is named for augustus caesar who became roman consul in this month. the month has 31 days because julius caesar added two days when he created the julian calendar in 45 bc. august is after july and before september.
august, in either hemisphere, is the seasonal equivalent of february in the other. in the northern hemisphere it is a summer month and it is a winter month in the southern hemisphere.
no other month in common years begins on the same day of the week as august, but august begins on the same day of the week as february in leap years. august ends on the same day of the week as november every year, as each other's last days are 13 weeks (91 days) apart.
in common years, august starts on the same day of the week as march and november of the previous year, and in leap years, june of the previous year. in common years, august finishes on the same day of the week as march and june of the previous year, and in leap years, september of the previous year. in common years immediately after other common years, august starts on the same day of the week as february of the previous year.
in years immediately before common years, august starts on the same day of the week as may of the following year, and in years immediately before leap years, october of the following year. in years immediately before common years, august finishes on the same day of the week as may of the following year, and in years immediately before leap years, february and october of the following year.
august observances
fixed observances and events
august 1 national day of switzerland
august 1 independence day (benin)
august 1 emancipation day (bermuda, guyana, jamaica, barbados, trinidad and tobago)
august 1 army day (people's republic of china)
august 1 lammas, cross-quarter day in the celtic calendar
august 1 statehood day (colorado)
august 2 republic day (republic of macedonia)
august 2 emancipation day (bahamas)
august 3 independence day (niger)
august 5 independence day (burkina faso)
august 5 victory day (croatia)
august 6 independence day (bolivia)
august 6 independence day (jamaica)
august 7 independence day (ivory coast)
august 8 father's day (taiwan)
august 9 national day of singapore
august 9 day of the indigenous people (suriname)
august 9 national women's day (south africa)
august 10 independence day (ecuador)
august 10 missouri day
august 11 independence day (chad)
august 12 perseid mete | 1,024 | 0 |
2 | august (aug.) is the eighth month of the year i [...] or shower
august 12 queen sirikit's birthday (thailand)
august 13 independence day (central african republic)
august 14 independence day (pakistan)
august 15 assumption of mary in western christianity
august 15 independence day (india)
august 15 independence day (republic of the congo)
august 15 independence day (bahrain)
august 15 national day of south korea
august 15 national day of liechtenstein
august 15 victory in japan day
august 17 independence day (indonesia)
august 17 independence day (gabon)
august 19 world humanitarian day
august 19 independence day (afghanistan)
august 20 feast day of stephen i of hungary
august 20 regaining of independence (estonia)
august 21 admission day (hawaii)
august 21 ninoy aquino day (philippines)
august 21 saint helena day
august 22 start of ashenda (ethiopia and eritrea)
august 23 national heroes day (philippines)
august 24 independence day (ukraine)
august 25 independence day (uruguay)
august 26 heroes' day (namibia)
august 27 independence day (moldova)
august 28 assumption of mary (eastern christianity)
august 29 national uprising day (slovakia)
august 30 constitution day (kazakhstan)
august 30 republic day (tatarstan)
august 30 victory day (turkey)
august 31 independence day (kyrgyzstan)
august 31 independence day (malaysia)
august 31 independence day (trinidad and tobago)
moveable and monthlong events
edinburgh festival, including the military tattoo at edinburgh castle, takes place through most of august and beginning of september.
uk bank holidays: first monday in scotland, last monday in england and wales
national eisteddfod, cultural celebration in wales: first week in august
children's day in uruguay: second sunday in august
monday after august 17: holiday in argentina, commemorating josé de san martin
discovery day in canada: third monday in august
summer olympics, often held in july and/or august
selection of historical events
august 1 1291: traditional founding date of switzerland.
august 1 1914: world war i begins.
august 1 1944: anne frank makes the last entry in her diary.
august 1 1960: dahomey (now called benin) becomes independent.
august 2 1990: iraq invades kuwait.
august 3 1492: christopher columbus sets sail on his first voyage.
august 3 1960: niger becomes independent.
august 4 1944: anne frank and her family are captured by the gestapo in amsterdam.
august 4 1984: upper volta's name is changed to burkina faso.
august 5 1960: upper volta becomes independent.
august 5 1962: film actress marilyn monroe is found dead at her home.
august 6 1825: bolivian independence.
august 6 1945: the atomic bomb is dropped on hiroshima.
august 6 1962: jamaica becomes independent.
august 7 1960: ivory coast becomes independent.
august 9 1945: the atomic bomb | 1,024 | 27 |
2 | august (aug.) is the eighth month of the year i [...] is dropped on nagasaki.
august 9 1965: singapore becomes independent.
august 9 1974: us president richard nixon resigns following the watergate scandal, with gerald ford replacing him.
august 10 1792: storming of the tuileries palace during the french revolution
august 10 1809: beginning of ecuadorean independence movement.
august 11 1960: chad becomes independent.
august 13 1960: the central african republic becomes independent.
august 13 1961: building of the berlin wall begins.
august 14 1945: japan announces its surrender at the end of world war ii.
august 14/15 1947: india is partitioned at independence from the uk, as the new mainly islamic state of pakistan is created.
august 15 1960: the republic of the congo becomes independent.
august 15 1971: bahrain becomes independent.
august 16 1977: elvis presley dies aged 42, leading to a worldwide outpouring of grief.
august 17 1945: indonesia declares independence from the netherlands.
august 17 1960: gabon becomes independent.
august 17 1962: peter fechter becomes the first person to be shot dead at the berlin wall.
august 19 43 bc: augustus becomes roman consul.
august 19 14: augustus dies.
august 19 1919: afghanistan becomes independent.
august 19 1991: the august coup against mikhail gorbachev, in the soviet union, begins.
august 20 1940: leon trotsky is fatally wounded with an ice pick in mexico.
august 20 1968: the prague spring uprising is crushed.
august 20 1991: estonia regains its independence from the soviet union.
august 21 1959: hawaii becomes the 50th state of the us.
august 24 79: vesuvius erupts, destroying pompeii and neighbouring herculaneum.
august 24 1991: ukraine regains independence from the soviet union.
august 24 2006: pluto is demoted to a dwarf planet.
august 25 1825: uruguay declares independence from brazil.
august 25 1989: voyager 2 flies by the planet neptune.
august 27 1883: krakatoa, in the sunda strait between sumatra and java, explodes, after a very violent eruption.
august 27 1991: moldova becomes independent from the soviet union.
august 28 1963: the march on washington for jobs and freedom takes place, where martin luther king, jr. makes his "i have a dream" speech for civil rights in the united states.
august 29 2005: hurricane katrina wreaks devastation in alabama, mississippi and louisiana. new orleans is flooded.
august 31 1957: malaysia, then the federation of malaya, becomes independent.
august 31 1962: trinidad and tobago becomes independent.
august 31 1991: kyrgyzstan becomes independent.
august 31 1997: diana, princess of wales is killed in a car crash in paris, leading to a big outpouring of grief.
trivia
along with july, august is one of two calendar months to be named after people who reall | 1,024 | 27 |
6 | art is a creative activity. it produces a product, an object. art is a diverse range of human activities in creating visual, performing subjects, and expressing the author's thoughts. the product of art is called a work of art, for others to experience.
some art is useful in a practical sense, such as a sculptured clay bowl that can be used. that kind of art is sometimes called a craft.
those who make art are called artists. they hope to affect the emotions of people who experience it. some people find art relaxing, exciting or informative. some say people are driven to make art due to their inner creativity.
"the arts" is a much broader term. it includes drawing, painting, sculpting, photography, performance art, dance, music, poetry, prose and theatre.
types of art
art is divided into the plastic arts, where something is made, and the performing arts, where something is done by humans in action. the other division is between pure arts, done for themselves, and practical arts, done for a practical purpose, but with artistic content.
plastic art
fine art is expression by making something beautiful or appealing to the emotions by visual means: drawing, painting, printmaking, sculpture
literature: poetry, creative writing
performing art
performing arts are expression using the body: drama, dance, acting, singing
auditory art (expression by making sounds): music, singing
practical art
culinary art (expression by making flavors and tastes): cooking
the practical arts (expression by making things and structures: architecture, filming, fashion, photography, video games)
what "art" means
some people say that art is a product or item that is made with the intention of stimulating the human senses as well as the human mind, spirit and soul. an artwork is normally judged by how much impact it has on people, the number of people who can relate to it, and how much they appreciate it. some people also get inspired.
the first and broadest sense of "art" means "arrangement" or "to arrange." in this sense, art is created when someone arranges things found in the world into a new or different design or form; or when someone arranges colors next to each other in a painting to make an image or just to make a pretty or interesting design.
art may express emotion. artists may feel a certain emotion and wish to express it by creating something that means something to them. most of the art created in this case is made for the artist rather than an audience. however, if an audience is able to connect with the emotion as well, then the art work may become publicly successful.
history of art
there are sculptures, cave painting and rock art dating from the upper paleolithic era.
all of the great ancient civilizations, such as ancient egypt, india, china, greece, rome and persia had works and styles of art. in the middle ages, most of the art in europe showed people from the bible in paintings, stained-glass windows, and mosaic tile floors and walls.
islamic art includes geometric patterns, islamic calligraphy, and architecture. in india and tibet, painted sculptures, dance, and religious painting were done. in china, arts included jade carving, bronze, pottery, poetry, calligraphy, music, painting, drama, and fiction. there are many chinese artistic styles, which are usually named after the ruling dynasty.
in europe, after the middle ages, there was a "renaissance" which means "rebirth". people rediscovered science and artists were allowed to paint subjects other than religious subjects. people like michelangelo and leonardo da vinci still painted religious pictures, but they also now could paint mythological pictures too. these artists also invented perspective where things in the distance look smaller in the picture. this was new because in the middle ages people would paint all the figures close up and just overlapping each other. these artists used n | 1,024 | 0 |
6 | art is a creative activity. it produces a product, an object. [...] udity regularly in their art.
in the late 1800s, artists in europe, responding to modernity created many new painting styles such as classicism, romanticism, realism, and impressionism. the history of twentieth century art includes expressionism, fauvism, cubism, dadaism, surrealism, and minimalism.
roles of art
in some societies, people think that art belongs to the person who made it. they think that the artist put his or her "talent" and industry into the art. in this view, the art is the property of the artist, protected by copyright.
in other societies, people think that art belongs to no one. they think that society has put its social capital into the artist and the artist's work. in this view, society is a collective that has made the art, through the artist.
functions of art
the functions of art include:
1) cognitive function
works of art let us know about what the author knew, and about what the surroundings of the author were like.
2) aesthetic function
works of art can make people happy by being beautiful.
3) prognostic function
some artists draw what they see the future like, and some of them are right, but most are not...
4) recreation function
art makes us think about it, not about reality; we have a rest.
5) value function
what did the artist value? what aims did they like/dislike in human activity? this usually is clearly seen in artists' works.
6) didactic function
what message, criticism or political change did the artist wish to achieve? | 456 | 27 |
8 | A or a is the first letter of the English alphabet. The small letter, a or α, is used as a lower case vowel.
When it is spoken, ā is said as a long a, a diphthong of ĕ and y. A is similar to Alphabet of the Greek alphabet. That is not surprising, because it means the same sound.
"Alpha and Omega" (the last letter of the Greek alphabet) means from beginning to the end. In musical notation, the letter A is the symbol of a note in the scale, below B and above G.
A is the letter that was used to represent a team in an old TV show, The A-Team. A capital a is written "A". Use a capital A at the start of a sentence if writing.
A is also a musical note, sometimes referred to as "La".
Where it came from
The letter 'A' was in the Phoenician alphabet's aleph. This symbol came from a simple picture of an ox head.
This Phoenician letter helped make the basic blocks of later types of the letter. The Greeks later modified this letter and used it as their letter alpha. The Greek alphabet was used by the Etruscans in northern Italy, and the Romans later modified the Etruscan alphabet for their own language.
Using the letter
The letter A has six different sounds. It can sound like æ, in the International Phonetic Alphabet, such as the word pad. Other sounds of this letter are in the words father, which developed into another sound, such as in the word ace.
Use in mathematics
In algebra, the letter "A" along with other letters at the beginning of the alphabet is used to represent known quantities.
In geometry, capital A, B, C etc. are used to label line segments, lines, etc. Also, A is typically used as one of the letters to label an angle in a triangle.
Its letter shape is referred to abstractly in Sir William Vallance Douglas Hodge's 5th postulate, the basis for, as one of the Millennium Prize Problems, the Hodge Conjecture. | 561 | 0 |
9 | Air is the Earth's atmosphere. Air is a mixture of many gases and tiny dust particles. It is the clear gas in which living things live and breathe. It has an indefinite shape and volume. It has mass and weight, because it is matter. The weight of air creates atmospheric pressure. There is no air in outer space.
Atmosphere is a mixture of about 78% nitrogen, 21% of oxygen, and 1% other gases, such as Carbon Dioxide.
Animals live and need to breathe the oxygen in the atmosphere. In breathing, the lungs put oxygen into the blood, and send back carbon dioxide to the air. Plants need the carbon dioxide in the air to live. They give off the oxygen that we breathe. Without it we die of asphyxia.
Air can be polluted by some gases (such as carbon monoxide, hydrocarbons, and nitrogen oxides), smoke, and ash. This air pollution causes various problems including smog, acid rain and global warming. It can damage people's health and the environment. There are debates about whether or not to act upon climate change, but soon enough the Earth will heat up to much, causing our home to become too hot and not support life! Some say fewer people would die of cold weather, and that is true but there is already a huge amount of people dying from heat and that number is and will keep increasing at a frighting height.
Since early times, air has been used to create technology. Ships moved with sails and windmills used the mechanical motion of air. Aircraft use propellers to move air over a wing, which allows them to fly. Pneumatics use air pressure to move things. Since the late 1900s, air power is also used to generate electricity.
Air is invisible: it cannot be seen by the eye, though a shimmering in hot air can be seen.
Air is one of the 4 classical elements.
Main history
Original atmosphere
At first it was mainly a hydrogen atmosphere. It has changed dramatically on several occasions—for example, the Great Oxygenation Event 2.4 billion years ago, greatly increased oxygen in the atmosphere from practically no oxygen to levels closer to present day. Humans have also contributed to significant changes in atmospheric composition through air pollution, especially since industrialisation, leading to rapid environmental change such as ozone depletion and global warming.
Second atmosphere
Outgassing from volcanism, supplemented by gases produced during the late heavy bombardment of Earth by huge asteroids, produced the next atmosphere, consisting largely of nitrogen plus carbon dioxide and inert gases.
Third atmosphere
The constant re-arrangement of continents by plate tectonics influences the long-term evolution of the atmosphere. Carbon dioxide was transferred to and from large continental carbonate stores. Free oxygen did not exist in the atmosphere until about 2.4 billion years ago. The Great Oxygenation Event is shown by the end of the banded iron formations. | 757 | 0 |
12 | Spain is divided in 17 parts called autonomous communities. Autonomous means that each of these autonomous communities has its own executive, legislative judicial powers. These are similar to, but not the same as, states in the United States of America, for example.
Spain has fifty smaller parts called provinces. In 1978 these parts came together, making the autonomous communities.
Before then, some of these provinces were together but were broken. The groups that were together once before are called "historic communities": Catalonia, Basque Country, Galicia and Andalusia.
The Spanish language is the sole official language in every autonomous community but six, where Spanish is co-official with other languages, as follows:
Catalonia: Catalan and Occitan
Valencian Community: Catalan (also called Valencian there)
Balearic Islands: Catalan
Galicia: Galician
Basque Country: Basque
Navarre: Basque (only in the north and near the border with the Basque County)
List of the autonomous communities, with their Capital city (the place where the government has its offices):
Andalusia (its capital is Sevilla)
Aragon (its capital is Zaragoza)
Asturias (its capital is Oviedo)
Balearic Islands (its capital is Palma de Mallorca)
Basque Country (its capital is Vitoria)
Canary Islands (they have two capitals - Las Palmas de Gran Canaria and Santa Cruz de Tenerife)
Cantabria (its capital is Santander)
Castile-La Mancha (its capital is Toledo)
Castile and León (its capital is Valladolid)
Catalonia (its capital is Barcelona)
Extremadura (its capital is Mérida)
Galicia (its capital is Santiago de Compostela)
La Rioja (its capital is Logroño)
Community of Madrid (its capital is Madrid)
Region of Murcia (its capital is Murcia)
Navarre (its capital is Pamplona)
Valencian Community (its capital is Valencia)
Spain also has two cities on the north coast of Africa: Ceuta and Melilla. They are called "autonomous cities" and have simultaneously the majority of the power of an autonomous community and also power of provinces and power of municipalities. | 645 | 0 |
13 | alan mathison turing obe frs (london, 23 june 1912 – wilmslow, cheshire, 7 june 1954) was an english mathematician and computer scientist. he was born in maida vale, london.
early life and family
alan mathison turing was born in maida vale, [london] on 23 june 1912. his father was part of a family of merchants from scotland. his mother, ethel sara, was the daughter of an engineer.
education
turing went to st. michael's, a school at 20 charles road, st leonards-on-sea, when he was five years old.
"this is only a foretaste of what is to come, and only the shadow of what is going to be." – alan turing.
the stoney family were once prominent landlords in north tipperary. his mother ethel sara stoney (1881–1976) was daughter of edward waller stoney (borrisokane, north tipperary) and sarah crawford (cartron abbey, co. longford), who were protestant anglo-irish gentry. she was educated in dublin at alexandra school and college. on october 1st 1907 she married julius mathison turing, who was reverend john robert turing and fanny boyd, in dublin. alan turing was born on june 23rd 1912. he would go on to be regarded as one of the greatest figures of the twentieth century.
alan was a brilliant mathematician and cryptographer. he became the founder of modern-day computer science and artificial intelligence. he designed a machine at bletchley park to break secret enigma encrypted messages used by the nazi german war machine to protect sensitive commercial, diplomatic and military communications during world war 2. this made the single biggest contribution to the allied victory in the war against nazi germany. it possibly saved the lives of an estimated 2 million people, and shortened world war ii.
in 2013, almost 60 years later, turing received a posthumous royal pardon from queen elizabeth ii. today, the "turing law" grants an automatic pardon to men who died before the law came into force, making it possible for living convicted gay men to seek pardons for offences now no longer on the statute book.
turing died in 1954, after being subjected by a british court to chemical castration. he is known to have ended his life at the age of 41 years, by eating an apple laced with cyanide.
career
turing was one of the people who worked on the first computers. he created the theoretical turing machine in 1936. the machine was imaginary, but it included the idea of a computer program.
turing was interested in artificial intelligence. he proposed the turing test, to say when a machine could be called "intelligent". a computer could be said to "think" if a human talking with it could not tell it was a machine.
during world war ii, turing worked with others to break german ciphers (secret messages). he worked for the government code and cypher school (gc&cs) at bletchley park, britain's codebreaking centre that produced ultra intelligence.
using cryptanalysis, he helped to break the codes of the enigma machine. after that, he worked on other german codes.
from 1945 to 1947, turing worked on the design of the ace (automatic computing engine) at the national physical laboratory. he presented a paper on 19 february 1946. that paper was "the first detailed design of a stored-program computer". although it was possible to build ace, there were delays in starting the project. in late 1947 he return | 1,024 | 0 |
13 | alan mathison turing obe frs (london, 23 june [...] ed to cambridge for a sabbatical year. while he was at cambridge, the pilot ace was built without him. it ran its first program on 10 may 1950.
private life
turing was a homosexual man. in 1952, he admitted having had sex with a man in england. at that time, homosexual acts were illegal. turing was convicted. he had to choose between going to jail and taking hormones to lower his sex drive. he decided to take the hormones. after his punishment, he became impotent. he also grew breasts.
in may 2012, a private member's bill was put before the house of lords to grant turing a statutory pardon. in july 2013, the government supported it. a royal pardon was granted on 24 december 2013.
death
in 1954, turing died from cyanide poisoning. the cyanide came from either an apple which was poisoned with cyanide, or from water that had cyanide in it. the reason for the confusion is that the police never tested the apple for cyanide. it is also suspected that he committed suicide.
the treatment forced on him is now believed to be very wrong. it is against medical ethics and international laws of human rights. in august 2009, a petition asking the british government to apologise to turing for punishing him for being a homosexual was started. the petition received thousands of signatures. prime minister gordon brown acknowledged the petition. he called turing's treatment "appalling". | 456 | 27 |
14 | alanis nadine morissette (born june 1, 1974) is a grammy award-winning canadian-american singer and songwriter. she was born in ottawa, canada. she began singing in canada as a teenager in 1990. in 1995, she became popular all over the world.
as a young child in canada, morissette began to act on television, including 5 episodes of the long-running series, you can't do that on television. her first album was released only in canada in 1990.
her first international album was jagged little pill, released in 1995. it was a rock-influenced album. jagged has sold more than 33 million units globally. it became the best-selling debut album in music history. her next album, supposed former infatuation junkie, was released in 1998. it was a success as well. morissette took up producing duties for her next albums, which include under rug swept, so-called chaos and flavors of entanglement. morissette has sold more than 60 million albums worldwide.
she also acted in several movies, including kevin smith's dogma, where she played god.
about her life
alanis morissette was born in riverside hospital of ottawa in ottawa, ontario. her father is french-canadian. her mother is from hungary. she has an older brother, chad, and a twin brother, wade, who is 12 minutes younger than she is. her parents had worked as teachers at a military base in lahr, germany.
morissette became an american citizen in 2005. she is still canadian citizen.
on may 22, 2010, morissette married rapper mario "mc souleye" treadway.
jagged little pill
morissette has had many albums. her 1995 album jagged little pill became a very popular album. it has sold over 30 million copies worldwide. the album caused morissette to win four grammy awards. the album jagged little pill touched many people.
on the album, morissette sang songs about many different things. these things include:
love (in the song "head over feet")
life (in the songs "ironic" and "you learn")
her feelings (in the songs "hand in my pocket" and "all i really want")
sadness (in the song "mary jane")
anger (in the song "you oughta know")
frustration (in the songs "not the doctor" and "wake up")
discography
albums
alanis (canada-only, 1991)
now is the time (canada-only, 1992)
jagged little pill (1995)
supposed former infatuation junkie (1998)
alanis unplugged (1999)
under rug swept (2002)
feast on scraps (cd/dvd, 2002)
so-called chaos (2004)
jagged little pill acoustic (2005)
alanis morissette: the collection (2005)
flavors of entanglement (2008)
havoc and bright lights (2012)
selected songs
morissette has written many songs. some of her most famous songs are:
"you oughta know" - this song is to morissette's ex-boyfriend, a man she once loved. in this song, morissette is very angry. she wants her ex-boyfriend to know that he caused many problems after leaving her for another woman.
"ironic" - this song is about life. it | 1,024 | 0 |
17 | Adobe Illustrator is a computer program for making graphic design and illustrations. It is made by Adobe Systems. Pictures created in Adobe Illustrator can be made bigger or smaller, and look exactly the same at any size. It works well with the rest of the products with the Adobe name.
History
It was first released in 1986 for the Apple Macintosh. The latest version is Adobe Illustrator CS6, part of Creative Suite 6.
Release history | 125 | 0 |
18 | Andouille is a type of pork sausage. It is spicy (hot in taste) and smoked. There are different kinds, all with different combinations of pork meat, fat, intestines (tubes going to the stomach), and tripe (the wall of the stomach).
Other sorts are "French andouille" and "German andouille"; they are less spicy than Cajun. Cajun has extra salt, black pepper, and garlic. Andouille makers smoke the sausages over pecan wood and sugar cane for a maximum of seven or eight hours, at about 175 degrees Fahrenheit (80 degrees Celsius).
Sausage | 185 | 0 |
19 | farming is growing crops and keeping animals for food and raw materials. farming is a major part of agriculture.
history
farming started thousands of years ago, but no one knows for sure how old it is. the development of farming gave rise to the neolithic revolution as people gave up nomadic hunting and became settlers in cities.
farming and domestication probably started in the fertile crescent (the nile valley, the levant and mesopotamia). the area called fertile crescent is now in the countries of iraq, syria, turkey, jordan, lebanon, israel, and egypt. wheat and barley are some of the first crops people grew.
cotton was domesticated in peru by 4200 bc.
livestock including horses, cattle, sheep, and goats were taken to the americas, from the old world. the first of those horses, came with the spanish conquistadors (or soldiers and explorers) in the 1490s. moving those cattle, sheep, goats and horses, were part of the columbian exchange.
people probably started agriculture by planting a few crops, but still gathered many foods from the wild. people may have started farming because the weather and soil began to change. farming can feed many more people than hunter-gatherers can feed on the same amount of land.
this allowed the human population to grow to such large numbers as there are today.
types
arable farming means growing crops. this would include wheat or vegetables.
growing fruit means having orchards devoted to fruit. they cannot be switched easily with growing field crops. therefore, they are not classed as arable land in the statistics.
many people still live by subsistence farming, on a small farm. they can only grow enough food to feed the farmer, his family, and his animals. the yield is the amount of food grown on a given amount of land, and it is often low. this is because subsistence farmers are generally less educated, and they have less money to buy equipment. drought and other problems sometimes cause famines. where yields are low, deforestation can provide new land to grow more food. this provides more nutrition for the farmer's family, but can be bad for the country and the surrounding environment over many years.
in some countries, farms are often fewer and larger. during the 20th century they have become more productive because farmers are able to grow better varieties of plants, use more fertilizer, use more water, and more easily control weeds and pests. many farms also use machines, so fewer people can farm more land. there are fewer farmers in rich countries, but the farmers are able to grow more.
this kind of intensive agriculture comes with its own set of problems. farmers use a lot of chemical fertilizers, pesticides (chemicals that kill bugs), and herbicides (chemicals that kill weeds). these chemicals can pollute the soil or the water. they can also create bugs and weeds that are more resistant to the chemicals, causing outbreaks of these pests. the soil can be damaged by erosion (blowing or washing away), salt builddup, or loss of structure. irrigation (adding water from rivers) can pollute water and lower the water table. these problems have all got solutions, and modern young farmers usually have a good technical education.
farmers select plants with better yield, taste, and nutritional value. they also choose plants that can survive plant disease and drought, and are easier to harvest. centuries of artificial selection and breeding have changed crop plants. the crops produce better yield. fertilizers, chemical pest control, and irrigation all help.
some plants are improved with genetic engineering. one example is modifying the plant to resist herbicides.
livestock
farms may also keep animals. that is called animal husbandry. if they are used to make meat for people to eat, | 1,024 | 0 |
19 | farming is growing crops and keeping animals for food and raw materials. farming is [...] that is livestock production. non-meat animals, such as milk cows and egg-producing chickens, are kept for their produce. "produce" here means their eggs and milk, which are sold by the farm, usually in markets. large animals need grassland of some kind for grazing. what they need depends on the animals. goats eat a much wider range of plants than cows. in some parts of the world, that makes goats a more sensible choice for a farmer than cows.
food
it is important for there to be enough food for everyone. the food must also be safe and good. people say it is not always safe, because it contains some chemicals. other people say intensive agriculture is damaging the environment. for this reason, there are several types of agriculture.
traditional agriculture is mostly done in poor countries.
intensive agriculture is mostly done in countries with more money. it uses pesticides, machinery, chemical fertilizers.
organic farming is using only natural products such as compost and green manure.
integrated farming is using local resources, and trying to use the waste from one process as a resource in another process.
agricultural policy means the goals and methods of agricultural production. common goals of policy include the quality, amount, and safety of food.
problems
there are some serious problems that people face trying to grow food today.
these include:
pollution
erosion
diseases
pests
weeds
drought
rainfall
climate: earth warming is an important example
contamination
there are also difficulties with the distribution of food:
warfare: see nigerian civil war (biafran war) for an example. see russia–ukrainian war for an example.
distribution: difficulties with moving product from grower to consumer. it is expected that this difficulty will increase in future. the reasons for this are complex, but one important factor may be the absence of a dominant international naval power. the british navy provided protection against pirates in the 19th and early 20th century, and the us navy protected shipping after wwii. the us is still a dominant naval power, but its power will soon be based on its small number of huge aircraft carriers. they will not deal with small boats full of armed pirates, which is the usual way piracy is done. so we can expect grain ships (etc) will have to carry any protection they may need, or they will have to go the long way around. that means avoiding the shortcuts into the mediterranean. other kinds of warfare, such as we see in the ukraine, adds to the problem of shipping food products safely.
crops
in produced weight, these crops are the most important (global production in metric tonnes):
the figure for sugarcane is rather deceptive. it omits sugar beet, but includes the weight of the woody stalk. most of the plants which produce food are in the grass family poaceae. | 779 | 27 |
21 | In mathematics, arithmetic is the basic study of numbers. The four basic arithmetic operations are addition, subtraction, multiplication, and division, although other operations such as exponentiation and roots are also studied in arithmetic.
Other arithmetic topics includes working with negative numbers, fractions, decimals and percentages.
Most people learn arithmetic in primary school, but some people do not learn arithmetic and others forget the arithmetic they learned. Many jobs require a knowledge of arithmetic, and many employers complain that it is hard to find people who know enough arithmetic. A few of the many jobs that require arithmetic include carpenters, plumbers, mechanics, accountants, architects, doctors, and nurses. Arithmetic is needed in all areas of mathematics, science, and engineering.
Some arithmetic can be carried out mentally. A calculator can also be used to perform arithmetic. Computers can do it more quickly, which is one reason Global Positioning System receivers have a small computer inside.
Examples of arithmetic
(addition is commutative: is the same as )
(subtraction is not commutative: is different from )
(multiplication is commutative: is the same as )
(division is not commutative: is different from | 357 | 0 |
22 | not to be confused with building extension which are also called additions
in mathematics, addition, represented by the symbol, is an operation which combines two mathematical objects together into another mathematical object of the same type, called the sum. addition can occur with simple objects such as numbers, and more complex objects and concepts such as vectors and matrices.
addition has several important properties. it is commutative, meaning that the order of the operands does not matter, and it is associative, meaning that when one adds more than two numbers, the order in which addition is performed does not matter (see summation). repeated addition of 1 is the same as counting. addition of 0 does not change a number. addition also obeys predictable rules concerning related operations such as subtraction and multiplication.
arithmetic
in arithmetic, addition is the operation where two or more numbers called "addends" are used to make a new number, which is the "sum" or total that is expressed with the equals sign. the symbol for addition, in infix notation, is the plus sign "+" placed between the operands.
counting examples
for example, there are objects in two groups (as shown on the right). the objects are various shapes, where one group has 3 of them while the other has 2. when the two groups combine into one, the overall amount (sum) of the shapes become 5.
vertical addition
the animation above demonstrates the addition of seven hundred eighty six and four hundred sixty seven. the problem's digits have been separated into units, tens and hundreds (see place value).
first, the units 6 and 7 are added together to make 13, so 1 ten and 3 units, with the 3 written below and the 1 ten carried to the tens column. next, in the tens column, the 1, 8, and 6 are added together to make 15 tens, so 1 hundred and 5 tens, with the 5 written below and the 1 hundred carried to the hundreds column. finally, in the hundreds column, 1, 7, and 4 are added together to make 12 hundreds, so 1 thousand and 2 hundreds, with the 2 written below and the 1 thousand carried to the thousand column. the final answer is thus one thousand two hundred fifty three.
a measurement example
tom wants to know the distance between his house and sally's house. bob's house is 300 m east of tom's house. sally's house is 120 m east of bob's house:
tom's house 300 m bob's house 120 m sally's house
the distance from tom's house to sally's house can be found by adding the distances already measured. the distance from tom's house to bob's house, added to the distance from bob's house to sally's house, is the same as the distance from tom's house to sally's house. that is, 300 m plus 120 m.
hence sally's house is 420 m to the east of tom's house.
properties
commutativity
addition is commutative, meaning that one can change the order of the numbers in a sum, but still get the same result. for example:
and
associativity
addition is also associative, which means that when three or more numbers are added together, the order of operations does not change the result.
for any three numbers,, and, it is true that. for example, and, which means that.
when addition is used together with other operations, the order of operations becomes important. in the standard order of operations, addition is to be computed later than exponentiation, roots, multiplication and division, but has equal importance as subtraction.
addition | 1,024 | 0 |
27 | australia (officially called the commonwealth of australia) is a country and sovereign state in the southern hemisphere, located in oceania. its capital city is canberra, and its largest city is sydney.
australia is the sixth biggest country in the world by land area, and is part of the oceanic and australasian regions. australia, new zealand, new guinea and other islands on the australian tectonic plate are together called australasia, which is one of the world's great ecozones. when other pacific islands are included with australasia, it is called oceania.
25 million people live in australia, and about 85% of them live near the east coast. the country is divided up into six states and two territories, and more than half of australia's population lives in and around the cities of sydney, melbourne, brisbane, perth and adelaide. the first people to live in the country were the indigenous australians: many of them died from smallpox during colonisation.
australia is known for its mining (coal, iron, gold, diamonds and crystals), its production of wool, and as the world's largest producer of bauxite. its emblem is a flower called the golden wattle.
australia is also known for its animals and rich wildlife. the national symbols of australia are the kangaroo and the golden wattle. scientifically, perhaps even more important are its two monotreme mammals: the platypus and the echidna.
geography
australia's landmass of is on the indo-australian plate. the continent of australia, including the island of tasmania, was separated from the other continents of the world many millions of years ago. because of this, many animals and plants live in australia that do not live anywhere else. these include animals like the kangaroo, the koala, the emu, the kookaburra, and the platypus.
people first arrived in australia more than 50,000 years ago. these native australians are called the australian aboriginals. for the history of australia, see history of australia.
most of the australian colonies, having been settled from britain, became mostly independent democratic states in the 1850s and all six combined as a federation on 1 january 1901. the first prime minister of australia was edmund barton in 1901. australia is a member of the united nations and the commonwealth of nations. it is a parliamentary democracy and a constitutional monarchy with king charles iii as king of australia and head of state and a governor-general who is chosen by the prime minister to carry out all the duties of the king in australia.
regions and cities
australia has six states, two major mainland territories, and other minor territories. the states are new south wales, queensland, south australia, victoria, western australia and tasmania (which is a large island). the two major mainland territories are the northern territory (which is huge) and the australian capital territory (act) which is not much more than a city.
the population is about 26 million people (2021 census = 25,890,773). most australians live in cities along the coast, such as sydney, melbourne, brisbane, perth, adelaide, newcastle and the gold coast. the largest inland city is canberra, which is also the nation's capital. the largest city is sydney.
australia is a very large country, but much of the land is very dry, and the middle of the continent is mostly a hot desert. only the areas around the east, west and south coast have enough rain and a suitable climate (not too hot and dry) for farms and cities. the island state of tasmania has a more balanced climate than much of the mainland.
climate change
all the capital cities except perth and darwin are in the south- | 1,024 | 0 |
27 | australia (officially called the commonwealth of australia) is a country [...] east of the country. there is now increasing rainfall and flooding which affects this region, which is ominous [threatening]. it is thought this is caused by climate change, and may continue to get worse. the bbc report comments: "in the past three years, record-breaking bushfire and flood events have killed more than 500 people and billions of animals. drought, cyclones and freak tides have gripped communities". the bbc report continues: "nowhere is this a bigger issue than in queensland. it is home to almost 40% of the 500,000 homes projected to be effectively uninsurable". this means people can't get insurance because the risk of flooding (in one season) or fire (in another season) is too great.
history
aboriginal people
the aboriginal and torres strait islander people arrived in australia about 60,000 years ago or maybe even earlier. until the arrival of british settlers in 1788, the aboriginal people lived by hunting and gathering food from the land. they lived in all sorts of climates and managed the land in different ways. an example of aboriginal land management was the cumberland plain where sydney is now. every few years the aboriginal people would burn the grass and small trees. this meant that a lot of grass grew back, but not many big trees. kangaroos like to live on grassy plains, but not in forests. the kangaroos that lived on the plain were a good food supply for the aboriginal people. sometimes, aboriginals would name a person after an animal, and they could not eat that animal to help level out the food population.
aboriginal people did not usually build houses, except huts of grass, leaves and bark. they did not usually build walls or fences, and there were no horses, cows or sheep in australia that needed to be kept in pens. the only aboriginal buildings that are known are fish-traps made from stones piled up in the river, and the remains of a few stone huts in victoria and tasmania. the aboriginal people did not use metal or make pottery or use bows and arrows or weave cloth. in some parts of australia the people used sharp flaked-stone spearheads, but most aboriginal spears were made of sharply pointed wood. australia has a lot of trees that have very hard wood that was good for spear making. the boomerang was used in some areas for sport and for hunting.
the aboriginal people did not think that the land belonged to them. they believed that they had grown from the land, so it was like their mother, and they belonged to the land.
terra australis
in the 1600s, dutch merchants traded with the islands of batavia (now indonesia), to the north of australia and several different dutch ships touched on the coast of australia. the dutch governor, van diemen, sent abel tasman on a voyage of discovery and he found tasmania, which he named van diemen's land. its name was later changed to honour the man who discovered it.
the british government was sure that there must be a very large land in the south, that had not been explored. they sent captain james cook to the pacific ocean. his ship, hms endeavour, carried the famous scientists, sir joseph banks and dr solander who were going to tahiti where they would watch the planet venus pass in front of the sun. captain cook's secret mission was to find "terra australis" (the land of the south).
the voyage of discovery was very successful, because they found new zealand and sailed right around it. then they sailed westward. at last, a boy, william hicks, who was up the mast spotted land on the horizon. captain cook named that bit of land point hicks. they sailed up the coast and captain | 1,024 | 27 |
27 | australia (officially called the commonwealth of australia) is a country [...] cook named the land that he saw "new south wales". at last they sailed into a large open bay which was full of fish and stingrays which the sailors speared for food. joseph banks and dr. solander went ashore and were astonished to find that they did not know what any of the plants or birds or animals that they saw were. they collected hundreds of plants to take back to england.
captain cook saw the aboriginal people with their simple way of life. he saw them fishing and hunting and collecting grass seeds and fruit. but there were no houses and no fences. in most parts of the world, people put up a house and a fence or some marker to show that they own the land. but the aboriginal people did not own the land in that way. they belonged to the land, like a baby belongs to its mother. captain cook went home to england and told the government that no-one owned the land. this would later cause a terrible problem for the aboriginal people.
settlement
in the 1700s, in england, laws were tough, many people were poor and gaols (jails) were full. a person could be sentenced to death for stealing a loaf of bread. many people were hanged for small crimes. but usually they were just thrown in gaol. often they were sent away to the british colonies in america. but by the 1770s, the colonies in america became the united states. they were free from british rule and would not take england's convicts any more, so england needed to find a new and less populated place.
by the 1780s the gaols of england were so full that convicts were often chained up in rotting old ships. the government decided to make a settlement in new south wales and send some of the convicts there. in 1788 the first fleet of eleven ships set sail from portsmouth carrying convicts, sailors, marines, a few free settlers and enough food to last for two years. their leader was captain arthur phillip. they were to make a new colony at the place that captain cook had discovered, named botany bay because of all the unknown plants found there by the two scientists.
captain phillip found that botany bay was flat and windy. there was not much fresh water. he went with two ships up the coast and sailed into a great harbour called port jackson, which he said was "the finest harbour in the world". there were many small bays on the harbour so he decided on one which had a good stream of fresh water and some flat shore to land on. on 26 january 1788, the flag was raised and new south wales was claimed in the name of king george iii of england, and the new settlement was called sydney.
for the first few years of the settlement, things were very difficult. no-one in the british government had thought very hard about what sort of convicts should be sent to make a new colony. nobody had chosen them carefully. there was only one man who was a farmer. there was no-one among the convicts who was a builder, a brick-maker or a blacksmith. no-one knew how to fix the tools when they broke. all of the cattle escaped. there were no cooking pots. all the plants were different so no-one knew which ones could be eaten. it was probable that everyone in the new colony would die of starvation.
the little group of tents had a hut for the governor, arthur phillip, and another hut for the supply of food. soon it grew into a small town with streets, a bridge over the stream, a windmill for grinding grain and wharves for ships. by the 1820s there was a fine brick house for the governor. there was also a hospital and a convict barracks and a beautiful church which are still standing today | 1,024 | 27 |
27 | australia (officially called the commonwealth of australia) is a country [...]. settlements had spread out from sydney, firstly to norfolk island and to van diemen's land (tasmania), and also up the coast to newcastle, where coal was discovered, and inland where the missing cattle were found to have grown to a large herd. spanish merino sheep had been brought to sydney, and by 1820, farmers were raising fat lambs for meat and also sending fine wool back to the factories of england.
while the settlement was growing in new south wales, it was also growing in tasmania. the climate in tasmania was more like that in england, and farmers found it easy to grow crops there.
exploration
because australia is such a very large land, it was easy to think that it might be able to hold a large number of people. in the early days of the colony, a great number of explorers went out, searching for good land to settle on.
when the settlers looked west from sydney, they saw a range of mountains which they called the blue mountains. they were not very high and did not look very rugged but for many years no-one could find their way through them. in 1813 gregory blaxland, william lawson and a 17-year-old called william charles wentworth crossed the blue mountains and found land on the other side which was good for farming. a road was built and the governor, lachlan macquarie founded the town of bathurst on the other side, 160 km (100 miles) from sydney. bathurst became australia's first inland settlement.
some people, like captain charles sturt were sure that there must be a sea in the middle of australia and set out to find it. many of the explorers did not prepare very well, or else they went out to explore at the hottest time of year. some died like burke and wills. ludwig leichhardt got lost twice. the second time, he was never seen again. major thomas mitchell was one of the most successful explorers. he mapped the country as he went, and his maps remained in use for more than 100 years. he travelled all the way to what is now western victoria, and to his surprise and annoyance found that he was not the first white person there. the henty brothers had come from tasmania, had built themselves a house, had a successful farm and fed the major and his men on roast lamb and wine.
self government
the gold rushes of new south wales and victoria started in 1851 leading to large numbers of people arriving to search for gold. the population grew across south east australia and made great wealth and industry. by 1853 the gold rushes had made some poor people very rich.
the transportation of convicts to australia ended in the 1840s and 1850s and more changes came. the people in australia wanted to run their own country, and not be told what to do from london. the first governments in the colonies were run by governors chosen by london. soon the settlers wanted local government and more democracy. william wentworth started the australian patriotic association (australia's first political party) in 1835 to demand democratic government. in 1840, the city councils started and some people could vote. new south wales legislative council had its first elections in 1843, again with some limits on who could vote. in 1855, limited self-government was given by london to new south wales, victoria, south australia and tasmania. in 1855, the right to vote was given to all men over 21 in south australia. the other colonies soon followed. women were given the vote in the parliament of south australia in 1895 and they became the first women in the world allowed to stand in elections.
australians had started | 1,024 | 27 |
27 | australia (officially called the commonwealth of australia) is a country [...] parliamentary democracies all across the continent. but voices were getting louder for all of them to come together as one country with a national parliament.
the commonwealth of australia
until 1901, australia was not a nation, it was six separate colonies governed by britain. they voted to join to form one new country, called the commonwealth of australia, in 1901. australia was still part of the british empire, and at first wanted only british or europeans to come to australia. but soon it had its own money, its own army and its own navy.
in australia at this time, the trade unions were very strong, and they started a political party, the australian labor party. australia passed many laws to help the workers.
in 1914, the first world war started in europe. australia joined in on the side of britain against germany, austria-hungary and the ottoman empire. australian soldiers were sent to gallipoli, in the ottoman empire. they fought bravely, but were beaten by the turks. today australia remembers this battle every year on anzac day. they also fought on the western front. more than 60,000 australians and new zealanders were killed.
in 1932, the sydney harbour bridge was opened.
australia had a really hard time in the great depression of the 1930s and joined britain in a war against nazi germany when hitler invaded poland in 1939. but in 1941 lots of australian soldiers were captured in the fall of singapore by japan. then japan started attacking australia and people worried about invasion. but with help from the united states navy, the japanese were stopped. after the war, australia became a close friend of the united states and japan.
when the war ended, australia felt that it needed many more people to fill the country up and to work. so the government said it would take in people from europe who had lost their homes in the war. it did things like building the snowy mountains scheme. over the next 25 years, millions of people came to australia. they came especially from italy and greece, other countries in europe. later they also came from countries like turkey and lebanon. an important new party, the liberal party of australia was made by robert menzies in 1944 and it won lots of elections from 1949 until in 1972, then gough whitlam won for the labor party. whitlam made changes, but he made the senate unhappy and the governor-general sacked him and forced an election in 1975. then malcolm fraser won a few elections for the liberal party.
in the 1960s many people began coming to australia from china, vietnam, malaysia and other countries in asia. australia became more multicultural. in the 1950s and 1960s australia became one of the richest countries in the world, helped by mining and wool. australia started trading more with america, than japan. australia supported the united states in wars against dictatorships in korea and vietnam and later iraq. australian soldiers also helped the united nations in countries like east timor in 1999.
in 1973, the famous sydney opera house opened. in the 1970s, 80s and 90s lots of australian movies, actors and singers became famous around the world. in the year 2000, sydney had the summer olympics.
in the 1980s and 90s, the labor party under bob hawke and paul keating, then the liberal party under john howard made lots of changes to the economy. australia had a bad recession in 1991, but when other western countries had trouble with their economies in 2008, australia stayed strong.
today australia is a rich, peaceful and democratic country. but it | 1,024 | 27 |
27 | australia (officially called the commonwealth of australia) is a country [...] still has problems. around 4-5% of australians could not get a job in 2010. a lot of land in australia (like uluru) has been returned to aboriginal people, but lots of aboriginals are still poorer than everybody else. every year the government chooses a big number of new people from all around the world to come as immigrants to live in australia. these people may come because they want to do business, or to live in a democracy, to join their family, or because they are refugees. australia took 6.5 million immigrants in the 60 years after world war two, including around 660,000 refugees.
julia gillard became the first woman prime minister of australia in 2010 when she replaced her labor party colleague kevin rudd (who later replaced her).
politics
australia is part of the commonwealth of nations. australia is made up of six states, and two mainland territories. each state and territory has its own parliament and makes its own local laws. the parliament of australia sits in canberra and makes laws for the whole country, also known as the commonwealth or federation.
the federal government is led by the prime minister of australia, who is the member of parliament chosen as leader. the current prime minister is anthony albanese.
the leader of australia is the prime minister, although the governor-general represents the queen of australia, who is also the queen of great britain, as head of state. the governor-general, currently his excellency david hurley, is chosen by the prime minister.
culture
australia was colonised by people from britain, but today people from all over the world live there. english is the main spoken language. christianity is the main religion, though all religions are accepted and not everybody has a religion. australia is multicultural: all its people are encouraged to keep their different languages, religions and ways of life, while also learning english and joining in with other australians. australia has many immigrants from different countries around the world.
famous australian writers include the bush balladeers banjo paterson and henry lawson who wrote about life in the australian bush. more modern famous writers include peter carey, thomas keneally and colleen mccullough. in 1973, patrick white won the nobel prize in literature, the only australian to have achieved this; he is seen as one of the great english-language writers of the twentieth century.
australian music has had world-wide stars, for example the opera singers nellie melba and joan sutherland, the rock and roll bands bee gees, ac/dc and inxs, the folk-rocker paul kelly (musician), the pop singer kylie minogue and australian country music stars slim dusty and john williamson. australian aboriginal music is very special and very ancient: it has the famous didgeridoo woodwind instrument.
australian tv has produced many successful programs for home and overseas. skippy the bush kangaroo, home and away and neighbours are examples. it has had well known tv stars, such as barry humphries (dame edna everage), steve irwin (the crocodile hunter) and the wiggles. major australian subgroups such as the bogan have been shown on australian tv in shows such as bogan hunters and kath & kim.
australia has two public broadcasters (the abc and the multicultural sbs), three commercial television networks, three pay-tv services, and numerous public, non-profit television and radio stations. each major city has its daily newspapers, and there are two national daily newspapers, the australian and the australian financial review.
australian movies have a long history. the world's first feature movie was the australian movie the story of the kelly gang of 1906. in 1933 | 1,024 | 27 |
27 | australia (officially called the commonwealth of australia) is a country [...], in the wake of the bounty, directed by charles chauvel, had errol flynn as the main actor. flynn went on to a celebrated career in hollywood. the first australian oscar was won by the 1942 kokoda front line!, directed by ken g. hall. in the 1970s and 1980s australian movies and movie stars became world famous. there were movies like picnic at hanging rock, gallipoli (with mel gibson), the man from snowy river and crocodile dundee. russell crowe, cate blanchett and heath ledger became global stars during the 1990s and australia starring nicole kidman and hugh jackman made a lot of money in 2008.
australia is a popular destination for business conferences and research, with sydney one of the top 20 meeting destinations in the world.
sport
sport is an important part of australian culture because the climate is good for outdoor activities. 23.5% australians over the age of 15 regularly take part in organised sporting activities. the most popular sports are australian rules football, rugby league and cricket. in international sports, australia has very strong teams in cricket, hockey, netball, rugby league and rugby union, and performs well in cycling, rowing and swimming. local popular sports include australian rules football, horse racing, soccer and motor racing. australia has participated in every summer olympic games since 1896, and every commonwealth games. australia has hosted the 1956 and 2000 summer olympics, and has ranked in the top five medal-winners since 2000. australia has also hosted the 1938, 1962, 1982 and 2006 commonwealth games and are to host the 2018 commonwealth games. other major international events held regularly in australia include the australian open, one of the four grand slam tennis tournaments, annual international cricket matches and the formula one australian grand prix. corporate and government sponsorship of many sports and elite athletes is common in australia. televised sport is popular; some of the highest-rated television programs include the summer olympic games and the grand finals of local and international football competitions.
the main sporting leagues for men are the afl (australian rules football), the nrl (rugby league), the a-league (soccer) and the nbl (basketball). for women, they are the aflw (australian rules football), anz netball championships (netball), the w-league (soccer) and wnbl (basketball).
famous australian sports players include the cricketer sir donald bradman, the swimmer ian thorpe, the cricketer shane warne and the athlete cathy freeman.
art festivals
just 60 years ago, australia had only one big art festival. now australia has hundreds of smaller community-based festivals, and national and regional festivals that focus on specific art forms.
indigenous life
australia is home to many animals and plants that can be found nowhere else on earth, except perhaps new guinea.
the platypus and the short-beaked echidna are unique, and are two of the only five surviving monotremes. monotremes are only found in australia and new guinea.
koalas, kangaroos, wombats, numbats and many others others, are marsupials. most of the marsupials in the world are found only on the continent or on the neighbouring island of new guinea. wildfires from global warming in 2020 have reduced the | 1,024 | 27 |
28 | american english or us english is the dialect of the english language spoken in the united states of america. it is different in some ways from other types of english, such as british english. most types of american english came from local dialects in england. during the 18th and 19th centuries, pronunciation changed less in america than in england.
use
many people today know about american english even if they live in a country where another type of english is spoken. they hear and read american english through the media, for example movies, television, and the internet, where the most common form of english is american english.
because people all over the world use the english language, it gets many new words. english has been changing in this way for hundreds of years. for example, the many millions who speak indian english frequently add american english words to go along with its british english base and many other words from the various indian languages.
sometimes people learn american english as it is spoken in the us. for example, in telephone call centers in india and other places, people often learn american english to sound more like their customers who call from the us. these people often keep using american english in everyday life.
spelling
there are many words that sound the same in both american and british english but have different spellings. british english often keeps more traditional ways of spelling words than american english.
vocabulary
there are also some words in american english that are a bit different from british english, e.g.:
aeroplane is called "airplane"
ladybird is called "ladybug"
lift is called "elevator"
toilet is called "bathroom", "restroom" or "comfort station"
lorry is called "truck"
nappies are called "diapers"
petrol is called "gas" (or "gasoline")
the boot of a car is called a "trunk"
a dummy is called a "pacifier"
trousers are called "pants"
underground is called "subway"
football is called "soccer"
braces are "suspenders" ("suspenders" in british-english are a type of clothing worn around the lower leg to stop socks/sox from sagging, or around the upper leg by people wearing stockings)
regional accents
general american english is the kind most spoken in mass media. it more vigorously pronounces the letter "r" than some other kinds do. "r-dropping" is frequent in certain places where "r" sound is not pronounced after a vowel. for example as in the words "car" and "card" sounding like "cah" and "cahd". this occurs in the boston area.
some regional accents of american english include
appalachian english - this is the stereotypical hillbilly accent. this accent is completely rhotic and can even have phantom rs (in words they don't belong)
general southern - this is a range of accents which tend to be rhotic or semi-rhotic, have glide deletion (in which i is converted to broad a)
tidewater english - a non-rhotic (r-dropping) southern variety that also has a "scottish" or "canadian" raising of the "ow" diphthong in words like "house" "about" "brown", etc.
charleston and savannah english - almost extinct accents that are non-rhotic
boston english (also east new england english) - this is the most famous non-rhotic american accent and what most other non-rhotic american varieties often get compared to. other bostonian features include limited canadian raising of the "ow" diphthong (before voiceless consonants such as in words like "house" | 1,024 | 0 |
30 | Aquaculture is the farming of fish, shrimp, abalones, algae, and other seafood. Aquaculture supplies fish, such as catfish, salmon, and trout. It was developed a few thousand years ago in China. Aquaculture supplies over 20% of all the seafood harvested.
Fish farming has been practiced, in some parts of the world, for thousands of years. Goldfish originated about a thousand years ago in carp farms in China, and the Roman Empire farmed oysters and other seafood. Today, half of the seafood eaten in the U.S. is farmed. To help meet the growing global demand for seafood, aquaculture is growing fast.
The environmental impact of fish farming varies widely, depending on the species being farmed, the methods used and where the farm is located. When good practices are used, it's possible to farm seafood in a way that has very little impact to the environment. Such operations limit habitat damage, disease, escapes of farmed fish and the use of wild fish as feed. | 269 | 0 |
32 | An abbreviation is a shorter way to write a word or phrase. People use abbreviations for words that they write a lot. The English language occasionally uses the apostrophe mark ' to show that a word is written in a shorter way, but some abbreviations do not use this mark. More often, they use periods, especially the ones that come from the Latin language. Common Latin abbreviations include i.e. [id est] that is, e.g. [exempli gratia] for example, and et al. [et alia] and others.
Some new abbreviations have been created by scientists, by workers in companies and governments, and by people using the Internet.
People often think words are abbreviations when in fact they are acronyms.
Here are examples of common acronyms: The word "radar" is an acronym for "Radio Detection and Ranging". The name of the large computer company IBM comes from the words "International Business Machines". The name of the part of the United States government that sends rockets into outer space is NASA, from the words "National Aeronautics and Space Administration". When people using the Internet think that something is very funny, they sometimes write "LOL" to mean "Laughing Out Loud". People sometimes write "ASAP" for "As Soon As Possible".
Other websites
Acronym Finder - largest acronym site with many ways to search for acronyms and abbreviations in many languages. Over 10-year history.
All Acronyms - a website with a large number of abbreviations and acronyms
Acronyms Abbreviations and Slang - over 3 million different acronyms and abbreviations in searchable database
SlangLang Abbreviations - Slang Words: 2,700 abbreviations and their meanings
Linguistics | 500 | 0 |
33 | in many mythologies and religions, an angel is a good spirit. the word angel comes from the greek word angelos which means "messenger". angels appear frequently in the old testament, the new testament, qur'an and aqdas.
different references to angels throughout the bible suggest different kinds and ranks of angels, such as seraphs (hebrew plural: seraphim) or cherubs (hebrew plural: cherubim). this resulted in medieval theologians outlining a hierarchy of such divine messengers, including not only cherubs and seraphs, but also archangels, powers, principalities, dominions and thrones.
the study of angels is called angelology.
in the bible
angels are powerful spirits that obey god's commands. they sometimes appear to humans in a human form. they can deliver messages to people in person or in dreams. angels that are named in the bible are michael (called a "chief prince"), gabriel (known for telling mary that she would be the mother of jesus), and raphael (in the apocryphal book of tobit). the ethiopian book of enoch also lists four archangels which watch over the four quadrants of heaven; michael, raphael, gabriel and uriel. lucifer is also known as an angel in the bible.
types
cherubs are described as creatures which have four wings. cherubim guard the eden with a sword of fire. this suggests that the author of genesis was aware of different types of angels. a cherub is mentioned in ezekiel 28:13-14, saying that the angel was in the garden of god.
ezekiel 28:13-14
13. thou hast been in eden the garden of god; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
14. thou art the anointed cherub that covereth; and i have set thee so: thou wast upon the holy mountain of god; thou hast walked up and down in the midst of the stones of fire.
it describes the sound of their wings, "like the roar of rushing waters."
ezekiel 10:5-7 ; ezekiel 10:8 reveals that they have hands like a man under their wings.
ezekiel 1:7 kjv reveals that they look like man but are different because they have "straight feet" and four wings and four faces.
ezekiel ch 1, and 10 describe the cherubim creatures ascending and descending from the earth with wheels. ezekiel 1:14-20 ; ezekiel 10:16
ezekiel 10:9-13 describes what the wheels appeared to look like, and how they moved around, how they moved or flew through the sky quickly but turned not as they went; and how the inside workings of the wheels appeared to be "a wheel in the midst of a wheel" and that the color of the wheels was the color of "amber" stone. there are four separate wheels in both accounts, one for each single cherub which is there.
seraphs (hebrew for "burning") are depicted as having six wings they are known for singing and praising god. they can shout so loud, they shake the temple.
archangels like gabriel (gospel of luke 1:19) are the highest type of angel. they are considered | 1,024 | 0 |
33 | in many mythologies and religions, an angel is a good spirit. the word ang [...] saints in the catholic church. however, in the king james version of the bible; they are another type of angel. in the book of revelation the angel michael casts the 'great dragon' satan out of heaven and down to earth in a great battle between the good and bad angels, just before the great judgement of angels and man. (revelation 12)
the leviathan in book of job 41:19-21 has flame that goes: 'out of his mouth' like a dragon. isaiah 30:6 also talks of a 'fiery flying serpent'. compare revelation 20:2:, where an angel: 'laid hold on the dragon, that old serpent, which is the devil, and satan, and bound him a thousand years'.
religion
rabbinic judaism
in judaism angels are created by god from fire. they fullfil tasks given by god. rabbinic judaism rejects earlier accounts on fallen angels who sinned by mating with humans. instead, angels are servants of god. still, not all angels are benevolent. some angels are jealous of humans, because god loves them so much. unlike angels, humans can overcome sin and repent. angels cannot repent their sin, because they are already sinless.
when the bible speaks about the creation of humans in the plural, judaism sometimes argues that god discussed his decision with the angels. but they make clear, it is god alone who creates humans. god only wanted to discuss with the angels to show that someone in power, should still try to value the opinion of people lower.
islam
in islam angels are created by god (allah) before jinn and humans. angels live in heaven and fullfil god's orders. some angels deliver messages to humans and prophets, most famous among them is gabriel. other angels support humans with rain. some angels don't have a task on earth, but dwell in heaven, for example, to praise god. muslims disagree if angels can fail a task, but they agree that an angel never want to disobey. sometimes angels might simply make mistakes on accident, like the angels harut and marut. but these angels are not considered evil, they just lose their rank as punishment, but can restore their rank later again. not all angels are nice. god gives angels violent tasks too. for example, god orders angels to punish people in hell, not demons. muslims believe hell is under god's control, and not the demon's. they believe hell is not only suffering, but also justice. angels watch out that people don't escape their punishment. while the benevolent angels are said to be created from light, some muslims think the angels in hell are created from fire.
in art
they are often shown in art as having wings and a halo. the wings represent their speed, and the halo represents their holiness.
the cherubim in art always appear as baby faced angels with very small, non-useful wings.
the cherubim statue or bronze casting of cherubim in the temple of solomon depicted them as two four winged creatures whose wings touched at the peak of the ark that they were making.
the same cherubim creatures were said to be cast in gold on top of the ark of the covenant. casting metal is one of the oldest forms of artwork, and was attempted by leonardo da vinci.
in literature
angels are generally held to be holy and virtuous, hence the term is used loosely to apply to anyone particularly good or kind, or having a good influence. in his novel far from the madding crowd, thomas hardy chooses the name of an angel, gabriel, for | 1,024 | 27 |
33 | in many mythologies and religions, an angel is a good spirit. the word ang [...] his kind and helpful hero. on the other hand, in his play measure for measure, shakespeare's use of the name angelo is ironic, since angelo is a character who likes to see himself as virtuous, but who is concealing evil aspects of his nature. fallen angels, who are no longer holy or virtuous, are also known as devils.
however, since angels are held to be spirits (that is, non-material beings), medieval theologians were faced with the problem of how humans could see a non-physical creature. eventually a theory was put forward that angels must make themselves a body out of the nearest thing to the non-physical, i.e. from air. hence in his famous poem aire and angels, the seventeenth century metaphysical poet john donne uses this idea to write a cynical comment on women, whose love, he says, is like an angel's body of air, while men's love is like the real thing, the angel itself.
idea of guardian angel
from the era of the romantics onwards, there has developed the widely held belief that everyone has an angel assigned to guard them. this concept is probably based on jesus' comment in matthew 18:10 regarding children, though it is not mentioned elsewhere in the bible.
in superstitions
seeing repetitive numbers are thought to be associated with numerology, also referred to as angel numbers. it is believed that angels communicate with humans through repetitive appearances of numbers. humanity has studied and used numbers since the dawn of time, and no matter what the culture is, there are certain numbers that hold specific value or meaning over other numbers. | 467 | 27 |
35 | Ad hominem is a Latin word for a type of argument. It is a word often used in rhetoric. Rhetoric is the science of speaking well, and convincing other people of your ideas.
Translated to English, ad hominem means against the person. In other words, when someone makes an ad hominem, they are attacking the person they are arguing against, instead of what they are saying.
The term comes from the Latin word homo, which means human. Hominem is a gender neutral version of the word homo. In ancient Rome it referred to all free men, or in other words, all free human beings.
Ad hominem can be a way to use reputation, rumors and hearsay to change the minds of other people listening. When a social network has already excluded or exiled one person, or applied a negative label to them, this can work more often.
It is most of the time considered to be a weak and poor argument. In courts and in diplomacy ad hominems are not appreciated.
Ad hominems are not wrong every time. For example, when people think that someone can't be trusted, things that they have said previously can be doubted.
What an ad hominem argument looks like
In logic, a proof is something that starts with premises, and goes through a few logical arguments, to reach a conclusion.
Normal (valid) proof
All humans are mortal.
Socrates is human.
Therefore, Socrates is mortal.
Ad hominem example
Person A thinks abortion should be illegal.
Person A is uneducated and poor.
Therefore, abortion should not be illegal.
In this example it can be seen that the (completely unrelated) fact that person A is uneducated and poor is used to prove that abortion should not be illegal. | 478 | 0 |
37 | native americans (also called aboriginal americans, american indians, amerindians or indigenous peoples of the americas) are the indigenous peoples and their descendants, who were in the americas before europeans arrived.
sometimes these people are called indians, but this may be confusing, because it is the same word used for people from india. when christopher columbus explored, he did not know about the americas. he was in the caribbean but thought he was in the east indies, so he called the people indians. today, some think that calling a native american an indian is racist.
there are many different tribes of native american people, with many different languages. some tribes were hunter-gatherers who moved from place to place. others lived in one place and built cities and kingdoms.
many native americans died after the europeans came to the americas. there were diseases that came with the europeans but were new to the native americans. there were battles with the europeans. many native people were hurt, killed, or forced to leave their homes by settlers who took their lands.
today, there are more than three million native americans in canada and the u.s. combined. about 51 million more native americans live in latin america. many native americans still speak native languages and have their own cultural practices, while others have adopted some parts of western culture. many native americans face problems with discrimination and racism.
origins
the ancestors of native americans came to the americas from asia. some of them may have come to america 15,000 years ago when alaska was connected to siberia by the bering land bridge.
the earliest people in the americas came from siberia when there was an ice bridge across the bering strait. the cold but mainly grassy plain which connected siberia with canada is called beringia. it is reckoned that a few thousand people arrived in beringia from eastern siberia during the last glacial maximum before moving into the americas sometime after 16,500 years before the present (bp). this would have occurred as the american glaciers blocking the way southward melted, but before the bridge was covered by the sea about 11,000 years bp.
before european colonization, beringia was inhabited by the yupik peoples on both sides of the straits. this culture remains in the region today, with others. in 2012, the governments of russia and the united states announced a plan to formally establish "a transboundary area of shared beringian heritage". among other things this agreement would establish close ties between the bering land bridge national preserve and the cape krusenstern national monument in the united states and beringia national park in russia.
native americans are divided into many small nations, called first nations in canada and tribes elsewhere.
culture
each native american tribe has their own culture. the cultures can be grouped together depending on region. for example, the tribes living in mesoamerica have similar cultures.
food
native americans ate many different things depending on where they lived.
native americans from mesoamerica introduced vanilla, avocados, and chocolate to the world.
religion
before europeans came, the native peoples of the americans practiced many different religions. each tribe had their own different beliefs.
today, many native americans practice christianity, a religion that was brought to the americas by europeans. meanwhile, others still practice their own religions.
languages
native americans today speak over a thousand different languages. some of these languages had writing systems before europeans came.
many of these languages are endangered because more people are speaking european languages and not teaching native american languages to their kids.
music
native americans make musical instruments using the things around them.
art
native americans made a lot of different art.
today
north america
united states
according to the 2010 united states census, 0.9% of americans say they | 1,024 | 0 |
37 | native americans (also called aboriginal americans, american indians, amerindians or [...] are native american, 2.9 million people, and 0.8% of americans say they are both native american and something else. they are not evenly spread out through the united states. about a third of the people in alaska are native alaskan and about a sixth of the people in oklahoma are native american.
in the united states, most native americans live in cities. about 28% of native americans live on indian reservations. many native americans are poor, and 24% are extremely poor. the history of violence against native americans persists today in higher rates of violence against native american people than white people.
mexico
many mexicans are of native american or mestizo ancestry. mexico has the largest and most diverse native american population in latin america.
canada
in the 2016 census, more than 1.67 million people in canada identified as indigenous, making them 4.9 per cent of canada's population.
central america
guatemala
about 40% of the people of guatemala identify as native american. many indigenous groups in the country are descendants of the maya.
many native americans in guatemala are poor. many of them have left the country to find better jobs elsewhere.
south america
bolivia
the majority of bolivians belong to indigenous groups. many are aymara and quechua.
peru
peru has a large indigenous population, around 80% of peru's population identify as indigenous or mestizo.
indigenous activism
in the later half of the 20th century, many native americans started to protest the unfair treatment they experienced from the societies they lived in.
some native americans have become famous in politics. for example, an aymara man named evo morales was elected as president of bolivia in 2005. he was the first indigenous presidential candidate in bolivia and south america. | 516 | 27 |
39 | an apple is the edible fruit of a number of trees, known for its juicy, green, or red fruits. the tree (malus spp.) is grown worldwide. its fruit is low-cost, popular, and common all over the earth.
applewood is a type of wood that comes from this tree.
the apple tree comes from southern kazakhstan, kyrgyzstan, uzbekistan, and northwestern part of china. apples have been grown for thousands of years in asia and europe. they were brought to north america by european settlers. apples have religious and mythological significance in many cultures.
apples are generally grown by grafting, although wild apples grow readily from seed. apple trees are large if grown from seed, but small if grafted onto roots (rootstock). there are more than 10000 known variants of apples, with a range of desired characteristics. different variants are bred for various tastes and uses: cooking, eating raw and cider production are the most common uses.
trees and fruit are attacked by fungi, bacteria and pests. in 2010, the fruit's genome was sequenced as part of research on disease control and selective breeding in apple production.
worldwide production of apples in 2013 was 90.8 million tonnes. china grew 49% of the total.
botanical information
the apple has a small, leaf-shedding tree that grows up to tall. the apple tree has a broad crown with thick twigs.
the leaves are alternately arranged simple ovals. they are 5 to 12 centimetres long and 3–6 centimetres (1.2–2.4 in) wide. it has a sharp top with a soft underside. blossoms come out in spring at the same time that the leaves begin to bud. the flowers are white. they also have a slightly pink color. they are five petaled, and 2.5 to 3.5 centimetres (0.98 to 1.4 in) in diameter. the fruit matures in autumn. it is usually 5 to 9 centimetres (2.0 to 3.5 in) in diameter. there are five carpels arranged in a star in the middle of the fruit. every carpel has one to three seeds.
wild ancestors
the wild ancestor of apple trees is malus sieversii. they grow wild in the mountains of central asia in the north of kazakhstan, kyrgyzstan, tajikistan, and xinjiang, china, and possibly also malus sylvestris. unlike domesticated apples, their leaves become red in autumn. they are being used recently to develop malus domestica to grow in colder climates.
history
the apple tree was possibly the earliest tree to be cultivated. its fruits have become better over thousands of years. it is said that alexander the great discovered dwarf apples in asia minor in 300 bc. asia and europe have used winter apples as an important food for thousands of years. from when europeans arrived, argentina and the united states have used apples as food as well. apples were brought to north america in the 1600s. the first apple orchard on the north american continent was said to be near boston in 1625. in the 1900s, costly fruit industries, where the apple was a very important species, began developing.
in culture
paganism
in norse mythology, the goddess iðunn gives apples to the gods in prose edda (written in the 13th century by snorri sturluson) that makes them young forever. english scholar h. r. ellis davidson suggests that apples were related to religious practices in germanic paganism. it was from there, she claims, that norse paganism developed. she points out that buck | 1,024 | 0 |
39 | an apple is the edible fruit of a number of trees, known for its [...] ets of apples were discovered in the place of burial for the oseberg ship in norway. she also remarks that fruit and nuts (iðunn having been described as changing into a nut in skáldskaparmál) have been discovered in the early graves of the germanic peoples in england. they have also been discovered somewhere else on the continent of europe. she suggests that this may have had a symbolic meaning. nuts are still a symbol of fertility in southwest england.
cooking
sometimes apples are eaten after they are cooked. often, apples are eaten uncooked. apples can also be made into drinks. apple juice and apple cider are drinks made with apples.
the flesh of the fruit is firm with a taste anywhere from sour to sweet. apples used for cooking are sour, and need to be cooked with sugar, while other apples are sweet, and do not need cooking. there are some seeds at the core, that can be removed with a tool that removes the core, or by carefully using a knife.
the scientific name of the apple tree genus in the latin language is malus. most apples that people grow are of the malus domestica species.
most apples are good to eat raw (not cooked), and are also used in many kinds of baked foods, such as apple pie. apples are cooked until they are soft to make apple sauce.
apples are also made into the drinks apple juice and cider. usually, cider contains a little alcohol, about as much as beer. the regions of brittany in france and cornwall in england are known for their apple ciders.
apple variants
if one wants to grow a certain type of apple, it is not possible to do this by planting a seed from the wanted type. the seed will have dna from the apple that the seeds came from, but it will also have dna from the apple flower that pollinated the seeds, which might be a different variant of apple. this means that the tree which would grow from planting would be a mixture of two, or a hybrid. in order to grow a certain type of apple, a small twig, or'scion', is cut from the tree that grows the type of apple desired, and then added on to a specially grown stump called a rootstock. the tree that grows will create apples of the type needed.
there are more than 7,500 known variants of apples. different variants are available for temperate and subtropical climates. one large collection of over 2,100 apple variants is at the national fruit collection in england. most of these variants are grown for eating fresh (dessert apples). however, some are grown simply for cooking or making cider. cider apples are usually too tart to eat immediately. however, they give cider a rich flavor that dessert apples cannot.
most popular apple cultivars are soft but crisp. colorful skin, easy shipping, disease resistance,'red delicious' apple shape, and popular flavor are also needed. modern apples are usually sweeter than older cultivars. this is because popular tastes in apples have become different. most north americans and europeans enjoy sweet apples. extremely sweet apples with hardly any acid taste are popular in asia and india.
world production
apples are grown around the world. china produces more than half of all commercially grown apples. in 2020/2021, china produced 44,066,000 metric tons. other important producers were the european union (eu) (11,719,000 metric tons, the united states (4,490,000 metric tons), and turkey (4,300,000 metric tons). total world production was 80,522,000 metric tons | 1,024 | 27 |
39 | an apple is the edible fruit of a number of trees, known for its [...].
in the united kingdom
in the united kingdom there are about 3000 different types of apples. the most common apple type grown in england is the 'bramley seedling', which is a popular cooking apple.
apple orchards are not as common as they were in the early 1900s, when apples were rarely brought in from other countries. organizations such as common ground teach people about the importance of rare and local varieties of fruit.
in north america
many apples are grown in temperate parts of the united states and canada. "washington state currently produces over half the nation's domestically grown apples and has been the leading apple-growing state since the early 1920s." new york and michigan are the next two leading states in apple production. "the total reported area dedicated to the crop in the united states is 336,940 acres or 526.47 square miles."
in many areas where apple growing is important, people have huge celebrations:
annapolis valley apple blossom festival - held five days every spring (may-june) in nova scotia
shenandoah apple blossom festival - held six days every spring in winchester, virginia.
washington state apple blossom festival - held two weeks every spring (april-may) in wenatchee, washington.
varieties of apples
there are many different varieties of apples, including:
aport
cox's orange pippin
fuji (apple)
gala
golden delicious (sometimes called a green delicious apple)
granny smith
jonathan
jonagold
mcintosh
pink lady
red delicious
winesap
yellow sweeting, the first variety of the u.s.
family
apples are in the group maloideae. this is a subfamily of the family rosaceae. they are in the same subfamily as pears. | 534 | 27 |
43 | An Abrahamic Religion is a religion whose followers believe in the prophet Abraham. They believe Abraham and his sons/grandsons hold an important role in human spiritual development. The best known Abrahamic religions are Judaism, Christianity and Islam. Smaller religious traditions sometimes included as Abrahamic religions are Samaritanism, Druze, Rastafari, Babism and Bahá'í Faith. Mandaeism (a religion that holds many Abrahamic beliefs) is not called Abrahamic because its followers think Abraham was a false prophet
True Abrahamic religions are monotheistic (the belief that there is only one God). They also all believe that people should pray to God and worship God often. Among monotheistic religions, the Abrahamic religions have the world's largest number of followers.
Religions
Mythology | 222 | 0 |
45 | algebra (from arabic: الجبر, transliterated "al-jabr", meaning "reunion of broken parts") is a part of mathematics. it uses variables to represent a value that is not yet known or can be replaced with any value. when an equals sign (=) is used, this is called an equation. a very simple equation using a variable is:. in this example,, or it could also be said that " equals five". this is called solving for.
besides equations, there are inequalities (less than and greater than). a special type of equation is called the function. this is often used in making graphs because it always turns one input into one output.
algebra can be used to solve real problems because the rules of algebra work in real life and numbers can be used to represent the values of real things. physics, engineering and computer programming are areas that use algebra all the time. it is also useful to know in surveying, construction and business, especially accounting.
people who do algebra use the rules of numbers and mathematical operations used on numbers. the simplest are adding, subtracting, multiplying, and dividing. more advanced operations involve exponents, starting with squares and square roots.
algebra was first used to solve equations and inequalities. two examples are linear equations (the equation of a straight line, or ) and quadratic equations, which has variables that are squared (multiplied by itself, for example:,, or ).
history
early forms of algebra were developed by the babylonians and greek geometers such as hero of alexandria. however the word "algebra" is a latin form of the arabic word al-jabr ("casting") and comes from a mathematics book al-maqala fi hisab-al jabr wa-al-muqabilah, ("essay on the computation of casting and equation") written in the 9th century by a persian mathematician, muhammad ibn mūsā al-khwārizmī, who was a muslim born in khwarizm in uzbekistan. he flourished under al-ma'moun in baghdad, iraq through 813-833 ce, and died around 840 ce. the book was brought into europe and translated into latin in the 12th century. the book was then given the name "algebra". (the ending of the mathematician's name, al-khwarizmi, was changed into a word easier to say in latin, and became the english word algorithm).
examples
here is a simple example of an algebra problem:
sue has 12 candies, and ann has 24 candies. they decide to share so that they have the same number of candies. how many candies will each have?
these are the steps you can use to solve the problem:
to have the same number of candies, ann has to give some to sue. let represent the number of candies ann gives to sue.
sue's candies, plus, must be the same as ann's candies minus. this is written as:
subtract 12 from both sides of the equation. this gives:. (what happens on one side of the equal sign must happen on the other side too, for the equation to still be true. so in this case when 12 was subtracted from both sides, there was a middle step of. after a person is comfortable with this, the middle step is not written down.)
add to both sides of the equation. this gives:
divide both sides of the equation by 2. this gives. the answer is six. this mean that if ann gives sue 6 candies, they will have the same number of candies.
to check this, put 6 back into the original equation wherever was:
this gives, which is true. they each now have 18 | 1,024 | 0 |
45 | algebra (from arabic: الجبر [...] candies.
with practice, algebra can be used when faced with a problem that is too hard to solve any other way. problems such as building a freeway, designing a cell phone, or finding the cure for a disease all require algebra.
writing algebra
as in most parts of mathematics, adding to (or plus ) is written as ;
subtracting from (or minus ) is written as ;
and dividing by (or over ) is written as or.
in algebra, multiplying by (or times ) can be written in 3 different ways:, or just. all of these notations mean the same thing: times. the symbol "" used in arithmetic is not used in algebra, because it looks too much like the letter, which is often used as a variable.
when we multiply a number and a variable in algebra, we can simply write the number in front of the letter:. when the number is 1, then it is not written because 1 times any number is that number and so it is not needed. and when it is 0, we can completely remove the terms, because 0 times any number is zero.
as a side note, you do not have to use the letters or in algebra. variables are just symbols that mean some unknown number or value, so you can use any letter for a variable (except (euler's number) and (imaginary unit), because these are mathematical constants). and are the most common, though.
functions and graphs
an important part of algebra is the study of functions, since they often appear in equations that we are trying to solve. a function is like a machine you can put a number (or numbers) into and get a certain number (or numbers) out. when using functions, graphs can be powerful tools in helping us to study the solutions to equations.
a graph is a picture that shows all the values of the variables that make the equation or inequality true. usually this is easy to make when there are only one or two variables. the graph is often a line, and if the line does not bend or go straight up-and-down it can be described by the basic formula. the variable is the y-intercept of the graph (where the line crosses the vertical axis) and is the slope or steepness of the line. this formula applies to the coordinates of a graph, where each point on the line is written.
in some math problems like the equation for a line, there can be more than one variable ( and in this case). to find points on the line, one variable is changed. the variable that is changed is called the "independent" variable. then the math is done to make a number. the number that is made is called the "dependent" variable. most of the time the independent variable is written as and the dependent variable is written as, for example, in. this is often put on a graph, using an axis (going left and right) and a axis (going up and down). it can also be written in function form:. so in this example, we could put in 5 for and get. put in 2 for would get. and 0 for would get. so there would be a line going through the points,, and as seen in the graph to the right.
if has a power of 1, it is a straight line. if it is squared or some other power, it will be curved. if it uses an inequality ( or ), then usually part of the graph is shaded, either above or below the line.
rules
in algebra, there are a few rules that can be used for further understanding of equations. these are called the rules of algebra. while | 1,024 | 27 |
45 | algebra (from arabic: الجبر [...] these rules may seem senseless or obvious, it is wise to understand that these properties do not hold throughout all branches of mathematics. therefore, it will be useful to know how these axiomatic rules are declared, before taking them for granted. before going on to the rules, reflect on two definitions that will be given.
opposite: the opposite of is.
reciprocal: the reciprocal of is.
commutative property of addition
commutative means that a function has the same result if the numbers are swapped around. in other words, the order of the terms in an equation does not matter. when two terms (addends) are being added, the commutative property of addition is applicable. in algebraic terms, this gives.
note that this does not apply for subtraction (i.e. except if ).
commutative property of multiplication
when two terms (factors) are being multiplied, the commutative property of multiplication is applicable. in algebraic terms, this gives.
note that this does not apply for division (i.e., when and, except if ).
associative property of addition
associative refers to the grouping of numbers. the associative property of addition implies that, when adding three or more terms, it doesn't matter how these terms are grouped. algebraically, this gives. note that this does not hold for subtraction, e.g. (see distributive property).
associative property of multiplication
the associative property of multiplication implies that, when multiplying three or more terms, it doesn't matter how these terms are grouped. algebraically, this gives. note that this does not hold for division, e.g..
distributive property
the distributive property states that the multiplication of a term by another term can be distributed. for instance:. (do not confuse this with the associative properties! for instance:.)
additive identity
identity refers to the property of a number that it is equal to itself. in other words, there exists an operation of two numbers so that it equals the variable of the sum. the additive identity property states that any number plus 0 is that number:. this also holds for subtraction:.
multiplicative identity
the multiplicative identity property states that any number times 1 is that number:. this also holds for division:.
additive inverse property
the additive inverse property is somewhat like the inverse of the additive identity. when we add a number and its opposite, the result is 0. algebraically, it states the following:, which is the same as. for example, the additive inverse (or opposite) of 1 is -1.
multiplicative inverse property
the multiplicative inverse property means that when we multiply a number and its reciprocal, the result is 1. algebraically, it states the following:, which is the same as. for example, the multiplicative inverse (or reciprocal) of 2 is 1/2. to get the reciprocal of a fraction, switch the numerator and the denominator: the reciprocal of is.
advanced algebra
in addition to "elementary algebra", or basic algebra, there are advanced forms of algebra, taught in colleges and universities, such as abstract algebra, linear algebra, and universal algebra. this includes how to use a matrix to solve many linear equations at once. abstract algebra is the study of things that are found in equations, going beyond numbers to the more abstract with groups of numbers.
many math problems are about physics and engineering. in many of these physics problems time is a variable. the letter used for time is. using the basic ideas in algebra can help reduce a math | 1,024 | 27 |
47 | an atom is the basic unit of matter. all normal matter – everything that has mass – is made of atoms. this includes solids, liquids, and gases. the atom cannot be broken to parts by chemistry, so people once thought it was the smallest and simplest particle of matter. there are over 100 different kinds of atoms, called chemical elements. each kind has the same basic structure, but a different number of parts.
atoms are very small, but their exact size depends on the type. atoms are from 0.1 to 0.5 nanometers across. one nanometer is about 100,000 times smaller than the width of a human hair. this makes one atom impossible to see without special tools. scientists learn how they work by doing experiments.
atoms are made of three kinds of subatomic particles. these are protons, neutrons, and electrons. protons and neutrons have much more mass. they are in the middle of the atom, the nucleus. lightweight electrons move quickly around them. the electromagnetic force holds the nucleus and electrons together.
atoms with the same number of protons belong to the same chemical element. examples of elements are carbon and gold. atoms with the same number of protons, but different numbers of neutrons, are called isotopes. usually an atom has the same number of electrons as protons. if an atom has more or less electrons than protons, it is called an ion, and has an electric charge.
atoms can join by chemical bonds. many things are made of more than one kind of atom. these are chemical compounds or mixtures. a group of atoms connected by chemical bonds is called a molecule. for example, a water molecule is made of two hydrogen atoms and one oxygen atom. the forming or breaking of bonds is a chemical reaction.
atoms split if the forces inside are too weak to hold them together. this is what causes radioactivity. atoms can also join to make larger atoms at very high temperatures, such as inside a star. these changes are studied in nuclear physics. most atoms on earth are not radioactive. they are rarely made, destroyed, or changed into another kind of atom.
history
the word "atom" comes from the greek (ἀτόμος) "atomos", which means indivisible or uncuttable. one of the first people to use the word "atom" is the greek philosopher democritus, around 400 bc. he thought that everything was made of particles called atoms, which could not be divided into smaller pieces. some hindu, jain, and buddhist philosophers also had ideas like this. atomic theory was a mostly philosophical subject, with not much scientific investigation or study, until the early 1800s.
in 1777 french chemist antoine lavoisier defined the term element as we now use it. he said that an element was any substance that could not be broken down into other substances by the methods of chemistry. any substance which could be broken down was a compound.
in 1803, english philosopher john dalton suggested that elements were made of tiny, solid balls called atoms. dalton believed that all atoms of the same element have the same mass. he said that compounds are formed when atoms of more than one element combine. in any one compound, the atoms would always combine in the same numbers.
in 1827, british scientist robert brown looked at pollen grains in water under his microscope. the pollen grains appeared to be shaking. brown used dalton's atomic theory to describe patterns in how they moved. this was called brownian motion. in 1905 albert einstein used mathematics to prove that the pollen particles were being moved by the motion, or heat, of individual water molecules. by doing this, he proved that atoms are real without question.
in 1869, russian scientist dmitri mendeleev published | 1,024 | 0 |
47 | an atom is the basic unit of matter. all normal matter – everything that has mass – is [...] the first periodic table. the periodic table groups elements by their atomic number (how many protons they have; this is usually the same as the number of electrons). elements in the same column, or group, usually have similar qualities. for example, helium, neon, argon, krypton, and xenon are all in the same column and are very similar. all these elements are gases that have no color or smell. also, they cannot combine with other atoms to form compounds. together they are known as noble gases.
the physicist j.j. thomson was the first person to discover electrons. this happened while he was working with cathode rays in 1897. he learned they had a negative charge, and the rest of the atom had a positive charge. thomson made the plum pudding model, which said that an atom was like plum pudding: the dried fruit (electrons) were stuck in a mass of pudding (having a positive charge).
in 1909, ernest rutherford used the geiger–marsden experiment to prove that most of an atom is in a very small space, the atomic nucleus. rutherford took a photo plate and covered it with gold foil. he then shot alpha particles (made of two protons and two neutrons stuck together) at it. many of the particles went through the gold foil, which proved that atoms are mostly empty space. electrons are so small and fast-moving that they did not block the particles from going through. rutherford later discovered protons in the nucleus.
in 1913, niels bohr created the bohr model. this model showed that electrons travel around the nucleus in fixed circular orbits. this was better than the rutherford model, but it was still not completely true.
in 1925, chemist frederick soddy discovered that some elements had more than one kind of atom, called isotopes. soddy believed that each different isotope of an element has a different mass. to prove this, chemist francis william aston built the mass spectrometer, which measures the mass of single atoms. aston proved that soddy was right. he also found that the mass of each atom is a whole number times the mass of the proton. this meant that there must be some particles in the nucleus other than protons. in 1932, physicist james chadwick shot alpha particles at beryllium atoms. he saw that a particle shot out of the beryllium atoms. this particle had no charge, but about the same mass as a proton. he named this particle the neutron.
the best model so far comes from the schrödinger equation. schrödinger learned that the electrons exist in a cloud around the nucleus, called the electron cloud. in the electron cloud, it is impossible to know exactly where electrons are. the schrödinger equation says where an electron is likely to be. this area is called the electron's orbital.
in 1937, german chemist otto hahn became the first person to make nuclear fission in a laboratory. he discovered this by chance when shooting neutrons at a uranium atom, hoping to make a new isotope. however, instead of a new isotope, the uranium changed into a barium atom, a smaller atom than uranium. hahn had "broken" the uranium atom. this was the world's first recorded nuclear fission reaction. this discovery led to the creation of the atomic bomb and nuclear power, where fission happens over and over again, creating a chain reaction.
later in the 20th century, physicists went deeper into the mysteries of the atom. using particle accelerators, they discovered that protons and neutrons were made of other particles, called quarks.
structure and parts
parts
| 1,024 | 27 |
47 | an atom is the basic unit of matter. all normal matter – everything that has mass – is [...] an atom is made of three main particles: the proton, the neutron, and the electron. protons and neutrons have nearly the same size and mass (about grams). the mass of an electron is about 1800 times smaller (about grams). protons have a positive charge, electrons have a negative charge, and neutrons have no charge. most atoms have no charge. the number of protons (positive) and electrons (negative) are the same, so the charges balance out to zero. however, ions have a different number of electrons than protons, so they have a positive or negative charge.
scientists believe that electrons are elementary particles: they are not made of any smaller pieces. protons and neutrons are made of quarks of two kinds: up quarks and down quarks. a proton is made of two up quarks and one down quark, and a neutron is made of two down quarks and one up quark.
nucleus
the nucleus is in the middle of the atom. it is made of protons and neutrons. the nucleus makes up more than 99.9% of the mass of the atom. however, it is very small: about 1 femtometer (10−15 m) across, which is around 100,000 times smaller than the width of an atom, so it has a very high density.
usually in nature, two things with the same charge repel or shoot away from each other. so for a long time, scientists did not know how the positively charged protons in the nucleus stayed together. we now believe that the attraction between protons and neutrons comes from the strong nuclear force. this force also holds together the quarks that make up the protons and neutrons. particles called mesons travel back and forth between protons and neutrons, and carry the force.
the number of neutrons in relation to protons defines whether the nucleus stays together or goes through radioactive decay. when there are too many neutrons or protons, the atom tries to make the numbers smaller or more equal by removing the extra particles. it sends out radiation in the form of alpha, beta, or gamma decay. nuclei can also change in other ways. nuclear fission is when the nucleus breaks into two smaller nuclei, releasing a lot of energy. this release of energy makes nuclear fission useful for making bombs, and electricity in the form of nuclear power.
the other way nuclei can change is through nuclear fusion, when two nuclei join or fuse to make a larger nucleus. this process requires very high amounts of energy to overcome the electric repulsion between the protons, as they have the same charge. such high energies are most common in stars like our sun, which fuses hydrogen for fuel. however, once fusion happens, far more energy is released, because some of the mass becomes energy.
the energy needed to break a nucleus into protons and neutrons is called its nuclear binding energy. this energy can be converted to mass, as stated by einstein's famous formula e = mc2. medium-sized nuclei, such as iron-56 and nickel-62, have the highest binding energy per proton or neutron. they will probably not go through fission or fusion, because they cannot release energy in this way. very small and very large atoms have low binding energy, so they are most willing to go through fission or fusion.
electrons
electrons orbit, or travel around, the nucleus. they are called the atom's electron cloud. they are attracted to the nucleus because of the electromagnetic force. electrons have a negative charge, and the nucleus always has a positive charge, so they attract each other.
the bohr model shows that some electrons are farther from the nucleus than others in different levels. these are called electron shells. only the electrons in the outer shell can make chemical bonds. the number of electrons in the | 1,024 | 27 |
47 | an atom is the basic unit of matter. all normal matter – everything that has mass – is [...] outer shell determines whether the atom is stable or which atoms it will bond with in a chemical reaction. if an atom has only one shell, it needs two electrons to be complete. otherwise, the outer shell needs eight electrons to be complete.
the bohr model is important because it has the idea of energy levels. the electrons in each shell have a certain amount of energy. shells that are farther from the nucleus have more energy. when a small burst of energy called a photon hits an electron, the electron can jump into a higher-energy shell. this photon must carry exactly the right amount of energy to bring the electron to the new energy level. a photon is a burst of light, and the amount of energy determines the color of light. so each kind of atom will absorb certain colors of light, called the absorption spectrum. an electron can also send out, or emit, a photon, and fall into a lower energy shell. for the same reason, the atom will only send out certain colors of light, called the emission spectrum.
the complete picture is more complicated. unlike the earth moving around the sun, electrons do not move in a circle. we cannot know the exact place of an electron. we only know the probability, or chance, that it will be in any place. each electron is part of an orbital, which describes where it is likely to be. no more than two electrons can be in one orbital; these two electrons have different spin.
for each shell, numbered 1, 2, 3, and so on, there may be a number of different orbitals. these have different shapes, or point in different directions. each orbital can be described by its three quantum numbers. the principal quantum number is the electron shell number. the azimuthal quantum number is represented by a letter: s, p, d, or f. depending on the principal and azimuthal quantum numbers, the electron can have more or less energy. there is also a magnetic quantum number, but it does not usually affect the energy level. as more electrons are added, they join orbitals in order from lowest to highest energy. this order starts as follows: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d. for example, a chlorine atom has 17 electrons. so, it will have:
2 electrons in the 1s orbital
2 electrons in the 2s orbital
6 electrons in the 2p orbitals
2 electrons in the 3s orbital
5 electrons in the 3p orbitals
in other words, it has 2 electrons in the first shell, 8 in the second shell, and 7 in the third shell.
properties
atomic number
the number of protons in an atom is called its atomic number. atoms of the same element have the same atomic number. for example, all carbon atoms have six protons, so the atomic number of carbon is six. today, 118 elements are known. depending on how the number is counted, 90 to 94 elements exist naturally on earth. all elements above number 94 have only been made by humans. these elements are organized on the periodic table.
atomic mass and weight
because protons and neutrons have nearly the same mass, and the mass of electrons is very small, we can call the number of protons and neutrons in an atom its mass number. most elements have several isotopes with different mass numbers. to name an isotope, we use the name of the element, followed by its mass number. so an atom with six protons and seven neutrons is called carbon-13.
sometimes, we need a more exact measurement. the exact mass of an atom is called its atomic mass. this is usually measured with the atomic mass unit (amu), also called the dalton. one amu is exactly 1/12 of the mass of a carbon-1 | 1,024 | 27 |
47 | an atom is the basic unit of matter. all normal matter – everything that has mass – is [...] 2 atom, which is grams. hydrogen-1 has a mass of about 1 amu. the heaviest atom known, oganesson, has a mass of about 294 amu, or grams. the average mass of all atoms of a particular element is called its atomic weight.
size
the size of an atom depends on the size of its electron cloud. moving down the periodic table, more electron shells are added. as a result, atoms get bigger. moving to the right on the periodic table, more protons are added to the nucleus. this more positive nucleus pulls electrons more strongly, so atoms get smaller. the biggest atom is caesium, which is about 0.596 nanometers wide according to one model. the smallest atom is helium, which is about 0.062 nanometers wide.
how atoms interact
when atoms are far apart, they attract each other. this attraction is stronger for some kinds of atoms than others. at the same time, the heat, or kinetic energy, of atoms makes them always move. if the attraction is strong enough, relative to the amount of heat, atoms will form a solid. if the attraction is weaker, they will form a liquid, and if it is even weaker, they will form a gas.
chemical bonds are the strongest kinds of attraction between atoms. the movement of electrons explains all chemical bonds.
atoms usually bond with each other in a way that fills or empties their outer electron shell. the most reactive elements have an almost full or almost empty outer shell. atoms with a full outer shell, called noble gases, do not usually form bonds.
there are three main kinds of bonds: ionic bonds, covalent bonds, and metallic bonds.
in an ionic bond, one atom gives electrons to another atom. each atom becomes an ion: an atom or group of atoms with a positive or negative charge. the positive ion (which has lost electrons) is called a cation; it is usually a metal. the negative ion (which has gained electrons) is called an anion; it is usually a nonmetal. ionic bonding usually results in a regular network, or crystal, of ions held together.
in a covalent bond, two atoms share electrons. this usually happens when both atoms are nonmetals. covalent bonds often form molecules, ranging in size from two atoms to many more. they can also form large networks, such as glass or graphite. the number of bonds that an atom makes (its valency) is usually the number of electrons needed to fill its outer electron shell.
in a metallic bond, electrons travel freely between many metal atoms. any number of atoms can bond this way. metals conduct electric current because electric charge can easily flow through them. atoms in metals can move past each other, so it is easy to bend, stretch, and change the shape of metals.
all atoms attract each other by van der waals forces. these forces are weaker than chemical bonds. they are caused when electrons move to one side of an atom. this movement gives a negative charge to that side. it also gives a positive charge to the other side. when two atoms line up their sides with negative and positive charges, they will attract.
although atoms are mostly empty space, they cannot pass through each other. when two atoms are very close, their electron clouds will repel each other by the electromagnetic force.
magnetism
to understand how magnets work, we can look at the properties of the atom. any magnet has a north and south pole, and a certain strength. the direction and strength of a magnet, together, are called its magnetic moment. every electron also has a magnetic moment, like a tiny magnet | 1,024 | 27 |
47 | an atom is the basic unit of matter. all normal matter – everything that has mass – is [...]. this comes from the electron's spin and its orbit around the nucleus. the magnetic moments for the electrons add up to a magnetic moment for the whole atom. this tells us how atoms act in a magnetic field.
every electron has one of two opposite spins. we can think of one as turning to the right, and the other as turning to the left. if every electron is paired with an electron with the opposite spin in the same orbital, the magnetic moments will cancel out to zero. atoms like this are called diamagnetic. they are only weakly repelled by a magnetic field.
however, if some electrons are not paired, the atom will have a lasting magnetic moment: it will be paramagnetic or ferromagnetic. when atoms are paramagnetic, the magnetic moment of each atom points in a random direction. they are weakly attracted to a magnetic field. when atoms are ferromagnetic, the magnetic moments of nearby atoms act on each other. they point in the same direction. this means that the whole object is a magnet, and it can point in the direction of a magnetic field. ferromagnetic materials, such as iron, cobalt, and nickel, are strongly attracted to a magnetic field.
radioactive decay
some elements, and many isotopes, have what is called an unstable nucleus. this means the nucleus is either too big to hold itself together, or it has too many protons or neutrons. when a nucleus is unstable, it has to eliminate the excess mass of particles. it does this through radiation. an atom that does this is called radioactive. unstable atoms emit radiation until they lose enough particles in the nucleus to become stable. all atoms above atomic number 82 (82 protons, lead) are radioactive.
there are three main kinds of radioactive decay: alpha, beta, and gamma.
alpha decay is when the atom shoots out a particle having two protons and two neutrons. this is a helium-4 nucleus. the result is an element with an atomic number of two less than before. so, for example, if a uranium atom (atomic number 92) went through alpha decay, it would become thorium (atomic number 90). alpha decay happens when an atom is too big and needs to lose some mass.
beta decay is when a neutron turns into a proton, or a proton turns into a neutron. in the first case, the atom shoots out an electron. in the second case, it shoots out a positron (like an electron but with a positive charge). the result is an element with one higher or one lower atomic number than before. beta decay happens when an atom has either too many protons or too many neutrons.
gamma decay is when an atom shoots out a gamma ray, or wave. it happens when there is a change in the energy of the nucleus. this is usually after a nucleus has gone through alpha or beta decay. there is no change in the atom's mass, or atomic number, only in the stored energy inside the nucleus, in the form of particle spin.
every radioactive element or isotope has a half-life. this is how long it takes half of any sample of atoms of that type to decay into a different isotope or element.
creation of atoms
nearly all the hydrogen atoms in the universe, most of the helium atoms, and some of the lithium atoms were made soon after the big bang. even today, about 90% of all atoms in the universe are hydrogen.
all other atoms come from nuclear fusion in stars, or sometimes from cosmic rays that hit atoms. at the start of their life, all stars fuse hydrogen to make helium. the | 1,024 | 27 |
48 | astronomy is the scientific study of celestial bodies. that means stars, galaxies, planets, moons, asteroids, comets and nebulae are studied, as are supernovae explosions, gamma ray bursts, and cosmic microwave background radiation. astronomy concerns the development, physics, chemistry, meteorology and movement of celestial bodies. the big questions are the structure and development of the universe.
astronomy is one of the oldest sciences. the patterns in the night sky were called constellations by the arabs. they used the positions of the stars to navigate, and to find when was the best time to plant crops.
astrophysics is an important part of astronomy. a related subject, cosmology, is concerned with studying the universe as a whole, and the way the universe changed over time. astronomy is not the same as astrology, a belief that the motion of the stars and the planets may affect human lives.
there are two main types of astronomy, observational and theoretical astronomy. observational astronomy uses telescopes and cameras to observe or look at stars, galaxies and other astronomical objects. theoretical astronomy explains what we see. it predicts what might happen. observations show whether the predictions work. the main work of astronomy is to explain puzzling features of the universe. for many years the most important issue was the motions of planets. many other topics are now studied.
day-time astronomy is possible. first, there's the sun, but observing directly is dangerous. it is too bright, and can burn your eyes and can cause permanent blindness. to look at the sun you need proper shields and equipment. some other individual bright stars and planets can be seen during daylight hours through a telescope or a powerful pair of binoculars.
history of astronomy
ancient history
early astronomers used only their eyes to look at the stars. they made maps of the constellations and stars for religious reasons and calendars to work out the time of year. early civilisations such as the maya people and the ancient egyptians built simple observatories and drew maps of the stars positions. they also began to think about the place of earth in the universe. for a long time people thought earth was the center of the universe, and that the planets, the stars and the sun went around it. this is known as geocentrism. astronomy is from the greek astron (ἄστρον) meaning "star" and nomos (nόμος) meaning "law")
ancient greeks tried to explain the motions of the sun and stars by taking measurements. a mathematician named eratosthenes was the first who measured the size of the earth and proved that the earth is a sphere. a theory by another mathematician named aristarchus was, that the sun is the center and the earth is moving around it. this is known as heliocentrism. only a few people thought it was right. the rest continued to believe in the geocentric model. most of the names of constellations and stars come from greeks of that time.
arabic astronomers made many advancements during the middle ages including improved star maps and ways to estimate the size of the earth. they also learned from the ancients by translating greek books into arabic.
renaissance to modern era
during the renaissance a priest named nicolaus copernicus thought, from looking at the way the planets moved, that the earth was not the center of everything. based on previous works, he said that the earth was a planet and all the planets moved around the sun. this brought back the old idea of heliocentrism. galileo galilei built his own telescopes, and used them to look more closely at the stars and planets for the first time. he agreed with copernicus. the catholic church thought galileo was wrong. he spent the rest of his life under house arrest. hel | 1,024 | 0 |
48 | astronomy is the scientific study of celestial bodies. that means stars, galaxies, [...] iocentric ideas were soon improved by johannes kepler and isaac newton, who invented the theory of gravity.
after galileo, people made better telescopes and used them to see farther objects such as the planets uranus and neptune. they also saw how stars were similar to our sun, but in a range of colours and sizes. they also saw thousands of other faraway objects such as galaxies and nebulae.
modern era
the 20th century after 1920 saw important changes in astronomy.
in the early 1920s it began to be accepted that the galaxy in which we live, the milky way, is not the only galaxy. the existence of other galaxies was settled by edwin hubble, who identified the andromeda nebula as a different galaxy. it was also hubble who proved that the universe was expanding. there were many other galaxies at large distances and they are receding, moving away from our galaxy. that was completely unexpected.
in 1931, karl jansky discovered radio emission from outside the earth when trying to isolate a source of noise in radio communications, marking the birth of radio astronomy and the first attempts at using another part of the electromagnetic spectrum to observe the sky. those parts of the electromagnetic spectrum that the atmosphere did not block were now opened up to astronomy, allowing more discoveries to be made.
the opening of this new window on the universe saw the discovery of entirely new things, for example pulsars, which sent regular pulses of radio waves out into space. the waves were first thought to be alien in origin because the pulses were so regular that (so it was thought) it implied an artificial source.
the period after world war ii saw more observatories. large and accurate telescopes were built and operated at good observing sites, usually by governments. for example, bernard lovell began radio astronomy at jodrell bank using leftover military radar equipment. by 1957, the site had the largest steerable radio telescope in the world. similarly, the end of the 1960s saw the start of the building of dedicated observatories at mauna kea in hawaii, a good site for visible and infra-red telescopes thanks to its high altitude and clear skies.
the next great revolution in astronomy was thanks to the birth of rocketry. this allowed telescopes to be placed in space on satellites.
space telescopes gave access, for the first time in history, to the entire electromagnetic spectrum including rays that had been blocked by the atmosphere. the x-rays, gamma rays, ultraviolet light and parts of the infra-red spectrum were all opened to astronomy as observing telescopes were launched. as with other parts of the spectrum, new discoveries were made.
from 1970s satellites were launched to be replaced with more accurate and better satellites, causing the sky to be mapped in nearly all parts of the electromagnetic spectrum.
discoveries
discoveries broadly come in two types: bodies and phenomena. bodies are things in the universe, whether it is a planet like our earth or a galaxy like our milky way. phenomena are events and happenings in the universe.
bodies
for convenience, this section has been divided by where these astronomical bodies may be found: those found around stars are solar bodies, those inside galaxies are galactic bodies and everything else larger are cosmic bodies.
solar
planets
asteroids
comets
galactic
stars
diffuse objects:
nebulas
clusters
compact stars:
white dwarf stars
neutron stars
black holes
cosmic
galaxies
galaxy clusters
superclusters
phenomena
burst events are those where there is a sudden change in the heavens that disappears | 1,024 | 27 |
48 | astronomy is the scientific study of celestial bodies. that means stars, galaxies, [...] quickly. these are called bursts because they are normally associated with large explosions producing a "burst" of energy. they include:
supernovas
novas
periodic events are those that happen regularly in a repetitive way. the name periodic comes from period, which is the length of time required for a wave to complete one cycle. periodic phenomena include:
pulsars
variable stars
noise phenomena tend to relate to things that happened a long time ago. the signal from these events bounce around the universe until it seems to come from everywhere and varies little in intensity. in this way, it is "noise", the background signal that pervades every instrument used for astronomy. the most common example of noise is static seen on analogue televisions. the principal astronomical example is: cosmic background radiation.
methods
instruments
telescopes are the main tool of observing. they take all the light in a big area and put in into a small area. this is like making your eyes very big and powerful. astronomers use telescopes to look at things that are far away and dim. telescopes make objects look bigger, closer, brighter.
spectrometers study the different wavelengths of light. this shows what something is made of.
many telescopes are in satellites. they are space observatories. the earth's atmosphere blocks some parts of the electromagnetic spectrum, but special telescopes above the atmosphere can detect that radiation.
radio astronomy uses radio telescopes. aperture synthesis combines smaller telescopes to create a phased array, which works like a telescope as big as the distance between the smaller telescopes.
techniques
there are way astronomers can get better pictures of the heavens. light from a distant source reaches a sensor and gets measured, normally by a human eye or a camera. for very dim sources, there may not be enough light particles coming from the source for it to be seen. one technique that astronomers have for making it visible is using integration (which is like longer exposures in photography).
integration
astronomical sources do not move much: only the rotation and movement of the earth causes them to move across the heavens. as light particles reach the camera over time, they hit the same place making it brighter and more visible than the background, until it can be seen.
telescopes at most observatories (and satellite instruments) can normally track a source as it moves across the heavens, making the star appear still to the telescope and allowing longer exposures. also, images can be taken on different nights so exposures span hours, days or even months. in the digital era, digitised pictures of the sky can be added together by computer, which overlays the images after correcting for movement.
adaptive optics
adaptive optics means changing the shape of the mirror or lens while looking at something, to see it better.
data analysis
data analysis is the process of getting more information out of an astronomical observation than by simply looking at it. the observation is first stored as data. this data then has various techniques used to analyse it.
fourier analysis
fourier analysis in mathematics can show if an observation (over a length of time) is changing periodically (changes like a wave). if so, it can extract the frequencies and the type of wave pattern, and find many things including new planets.
subfields of astronomy
pulsars pulse regularly in radio waves. these turned out to be similar to some (but not all) of a type of bright source in x-rays called a low-mass x-ray binary. it turned out that all pulsars and some lmxbs are neutron stars and that the differences were due to the environment in which the neutron star was found. those lmxbs that were not neutron stars turned out to be black holes.
this section attempts to provide | 1,024 | 27 |
48 | astronomy is the scientific study of celestial bodies. that means stars, galaxies, [...] an overview of the important fields of astronomy.
solar astronomy
solar astronomy is the study of the sun. the sun is the closest star to earth at around 92 million (92,000,000) miles away. it is the easiest to observe in detail. observing the sun can help us understand how other stars work and are formed. changes in the sun can affect the weather and climate on earth. a stream of charged particles called the solar wind is constantly sent off from the sun. the solar wind hitting the earth's magnetic field causes the northern lights.
stellar astronomy
stellar astronomy, sometimes generally stellar astrophysics is the scientific study of stars, their formation, evolution and fate (stellar evolution). in the most basic sense,stellar astronomy attempts to answer the questions to the universe's most common phenomena — stars. heavily relating with galactic and planetary astronomy.
planetary astronomy
planetary astronomy is the study of planets, moons, dwarf planets, comets and asteroids as well as other small objects that orbit stars. the planets of our own solar system have been studied in depth by many visiting spacecraft such as cassini-huygens (saturn) and the voyager 1 and 2.
galactic astronomy
galactic astronomy is the study of distant galaxies. studying distant galaxies is a good way of learning about our own galaxy, as the gases and stars in our own galaxy make it difficult to observe. galactic astronomers try to understand the structure of galaxies and how they are formed by using different types of telescopes and computer simulations.
gravitational wave astronomy
gravitational wave astronomy is the study of the universe in the gravitational wave spectrum. so far, all astronomy that has been done has used the electromagnetic spectrum. gravitational waves are ripples in spacetime emitted by very dense objects changing shape, which include white dwarves, neutron stars and black holes. because no one has been able to detect gravitational waves directly, the impact of gravitational wave astronomy has been limited.
unsolved problems
great discoveries also produce unsolved problems. this is just a short-list:
dark matter and dark energy: what are they?
ultimate fate of the universe? what will it be?
why is lithium 4 times less than predicted?
origin of supermassive black holes.
the source of ultra-high energy cosmic rays.
the existence of life elsewhere. | 699 | 27 |
49 | architecture is the process of designing structures and buildings. it uses both art and engineering. examples include houses, churches, hotels, office buildings, roads, viaducts, tunnels and bridges.
architecture is the profession of an architect. usually, a person must study at an institution of higher education (university) to become an architect. there were architects long before there was higher education. they learnt by being an apprentice to an established architect.
architecture can do small designs, such as for a garage, or large designs, such as for a whole city. the capital cities of brasília, and canberra were designed. architects often work with structural engineers to make structurally sound buildings.
history
in the past, people built huts and wood houses to protect themselves from the weather. for safety, they were often close together. great civilizations like the ancient egyptians built large temples and structures, like the great pyramids of giza. the ancient greeks and romans made what we now call "classical architecture". the romans, working over 2000 years ago, copied the arch from the etruscans, who copied it from the mesopotamians.
classical architecture was formal, and it always obeyed laws. it used symmetry, which really means balance, and it used proportion between shapes. the golden mean was a rule which said, (to put it simply) if you are making a room, or any other thing, it will work best if you always make the long side 1.6 times as long as the short side. there are many 'laws' in classical architecture, like how high the middle of an arched bridge needs to be (which depends on how wide the bridge needs to be). these laws were learned from thousands of years of experience and they are often used today. however, today more notice is taken of specific facts, such as what wind speeds occur once or twice in a century. several bridges have blown down because that was not properly taken into consideration.
in some parts of the world, like india, the architecture is famous for carving the stone on temples and palaces. different architectural styles occur in china, japan, southeast asia, africa, mexico, and central and south america.
architects in western europe in the middle ages made romanesque architecture, then gothic architecture. gothic buildings have tall, pointed windows and arches. many churches have gothic architecture. castles were also built at this time. in eastern europe, churches usually had domes. people added their own ideas and decoration to the classical architecture of the past. the renaissance brought a return to classical ideas.
in the late 18th century with the industrial revolution, people began to invent machines to make things quickly and cheaply. many factories and mills were built during, or after this revolution. decades later, in the victorian era, architects like george fowler jones and decimus burton still followed the gothic style to build new churches. up to this point, buildings were limited in size and style by the strength of the wood and masonry used to construct them. gothic cathedrals were among the largest buildings because the gothic arch when combined with buttresses allowed stone buildings to be built taller. for example, the cathedral in ulm, germany is over 500 feet tall. however, building with stone has its limits, and building too tall could result in collapse. this happened to the beauvais cathedral, which was never completed.
towards the end of the 19th century with a second industrial revolution, steel became much cheaper. architects began to use inventions like metal girders and reinforced concrete to build. an example is the eiffel tower in paris. buildings can now be built taller than ever before. we call them skyscrapers. this new technology has made us free from traditional limitations, and because of the new possibilities presented by these materials, many traditional methods of construction and ideas about style were reevaluated, replaced, or abandoned. cheap, strong glass soon | 1,024 | 0 |
50 | Anatomy is the study of the bodies of people and other animals. Anatomy is the study of the inside of the body and outside the body. Anatomy notes the position and structure of organs such as muscles, glands and bones. A person who studies anatomy is an anatomist.
The history of anatomy dates back to 1600 BC when Egyptians began studying human anatomy. They discovered the functions of many organs like the liver, spleen, kidneys, heart etc. and were the first to discover the structure and functions of the lymphatic system.
For long periods the dissection of deceased people was forbidden, and correct ideas about human anatomy was a long time coming.
Academic human anatomists are usually employed by universities, medical schools and teaching hospitals. They are often involved in teaching and research. Gross anatomy studies parts of the body that are big enough to see. Micro-anatomy studies smaller parts.
Body systems
There are different organ systems, such as the cardiovascular system, also known as the circulatory system (the system that gets blood around the body), the muscular system (the system that contains muscles), the nervous system (the system that controls the nerves,and the brain) and the skeleton (the bones).
Anatomy, physiology and biochemistry are similar basic medical sciences. | 352 | 0 |
51 | An asteroid is a minor planet that orbits within the inner solar system. It is a small object in the Solar System that travels around the Sun. It is like a planet but smaller. They range from very small (smaller than a car) to 600 miles (1000 km) across. A few asteroids have asteroid moon.
The name "asteroid" means "like a star" in the ancient Greek language. Asteroids may look like small stars in the sky, but they really do move around the Sun. Like planets, asteroids do not make their own light. Because of this, some people think "asteroids" is not a good name, and think that the name "planetoid" ("like a planet") would be a better name.
Giuseppe Piazzi found the first asteroid, in 1801. He called it Ceres, and it is the biggest object in the asteroid belt. Others, like Juno, Pallas, and Vesta were found later. In the 1850s, so many had been found that they were numbered by a Minor planet designation starting with 1 Ceres. Today, astronomers using computerized telescopes find thousands of asteroids every month. Asteroid impact prediction is one of their purposes.
Asteroids are the leftover rock and other material from the formation of the Solar System. These rocks were too small to come together to make a planet. Some are made of carbon or metal. Depending on what's on the surface, they are classified into various asteroid spectral types including Type M (metal), Type S (stone), and Type C (carbon).
Most asteroids in our Solar System are in the asteroid belt between Mars and Jupiter. Many are not in the main asteroid belt. The ones that come close to Earth are called Near-Earth asteroids. Some scientists think asteroids striking the Earth killed off all the dinosaurs and caused some of the other extinction events. | 540 | 0 |
52 | afghanistan, officially the islamic emirate of afghanistan (pashto/dari: ), is a country in central asia. it borders with pakistan in the south and east, iran in the west, turkmenistan, uzbekistan and tajikistan in the north, and china in the far northeast. kabul is the country's capital city.
afghanistan is currently governed by the taliban, after the collapse of the internationally recognized islamic republic of afghanistan on 15 august 2021. in early times people passed through it with animals and other goods as it connected china and india with central asia and the middle east. more recently, afghanistan has been damaged by many years of war. there are not enough jobs.
the country is around in size. there are 40.976 million people in afghanistan. there are about 3 million afghan refugees (people who had to leave the country) who are in pakistan and iran for some time. in 2011, its capital, kabul, had about 3,691,400 people living in it.
united nations human rights council decided in october to appoint (an independent expert, or) united nations special rapporteur on "afghanistan to [find out about, or] probe violations carried out by the taliban and" others who are now part of a [big] conflict, media said.
geography
afghanistan has many mountains. the mountains are called the hindu kush and himalayas. the tallest mountain in afghanistan is mount nowshak. there are plains (which have soil that is good for growing plants) and foothills. parts of the country are also dry, especially the registan desert.
afghanistan has snow and glaciers in the mountains. amu darya is the big water stream, or river.
the country has an abundance of a valuable stone called lapis lazuli, which was also used to decorate the tomb of the egyptian pharaoh tutankhamun.
climate
afghanistan has a continental climate with hot summers and cold winters. having no water sometimes causes problems for farmers. sandstorms happen a lot in the desert.
plants and animals
southern afghanistan has not many plants because it is dry. there are more plants where there is more water. mountains have forests of pine and fir, cedar, oak, walnut, alder, and ash trees.
afghanistan's wild animals live in the mountains. there are wolves, foxes, jackals, bears, and wild goats, gazelles, wild dogs, camels, and wild cats such as the snow leopard in the country. the birds are falcons, eagles and vultures. the rhesus macaque and the red flying squirrel are also in afghanistan.
many years of war, hunting, and years of no water have killed animals in afghanistan. there used to be tigers in afghanistan, but now there aren't any. bears and wolves are almost gone.
people and culture
many people have moved through or invaded the land of afghanistan. today's people of afghanistan are known as afghans. they have many traits passed down from these previous peoples.
the largest group of people are the pashtuns. these make up about half the population. tajiks are the second-largest ethnic group, making up about one-fifth of the population. before the 20th century, tajiks were called sarts and some come from the iranian peoples. most pashtuns are also related to the iranian peoples. some pashtuns and tajiks marry each other but at the same time they are rivals. the third-largest group are the hazaras. they are native to the hazaristan area in central afghanistan. the country | 1,024 | 0 |
52 | afghanistan, officially the islamic emirate of afghanistan ( [...]'s other groups include the uzbek, aimaq, turkmen, nuristani, baloch, pashayi and a few others.
dari-persian and pashto are the official languages of afghanistan. many people speak both languages. both are indo-european languages from the iranian languages sub-family. they are usually written with the arabic alphabet. uzbek and turkmen are widely spoken in the north and nuristani and pashai are spoken in the east. around 99% of all afghans follow the religion of islam.
afghanistan is a largely rural country. this means there are only a few major cities. about one fifth of the population live in cities. kabul, the capital, is the largest city. it is south of the hindu kush range and alongside the kabul river. other cities in afghanistan include kandahar, herat, mazar-e sharif, and jalalabad. the rural population is made up of farmers and nomads. the farmers live mainly in small villages along the rivers. the nomads live in tents while moving from place to place with their animals and belongings. some people live in the high central mountains. some live in the deserts in the south and southwest. millions of people left afghanistan to get away from the wars that happened in the late 20th and early 21st centuries. most of them lived in neighboring pakistan and iran.
history
afghanistan is in the path of important trade routes that connect southern and eastern asia to europe and the middle east. because of this, many empire builders have decided to rule over the area. signs that these emperors were near afghanistan still exist in many parts of the country. afghanistan is near what used to be the silk road, so it has many cultures. from up to 8,000 years ago, the peoples of afghanistan helped develop (create) major world religions, traded and exchanged many products, and sometimes controlled politics and culture in asia.
prehistory
archaeologists digging a cave in what is now northeastern afghanistan (in badakhshan), discovered that people lived in the country as early as 100,000 years ago. they found the skull of a neanderthal, or early human, as well as tools from about 30,000 years ago. in other parts of afghanistan, archaeologists uncovered pottery and tools that are 4,000 to 11,000 years old—evidence that afghans were among the first people in the world to grow crops and raise animals.
farmers and herders settled in the plains surrounding the hindu kush as early as 7000 b.c. these people may have grown rich off the lapis lazuli they found along riverbeds, which they traded to early city sites to the west, across the iranian plateau and mesopotamia. as farms and villages grew and thrived in afghanistan, these ancient people eventually invented irrigation (digging ditches for water so it flows to crops) that allowed them to grow crops on the northern afghanistan desert plains. this civilization (advanced state of organization) is today called bmac (bactria–margiana archaeological complex), or the "oxus civilization".
the oxus civilization expanded as far east as western edge of the indus valley during the period between 2200 and 1800 b.c. these people, who were the ancestors of the indo-aryans, used the term "aryan" to identify their ethnicity, culture, and religion. scholars know this when they read the ancient texts of these people; the avesta of iranic peoples and the vedas of indo-aryans.
zoroaster, the founder of the zoroastrian | 1,024 | 27 |
52 | afghanistan, officially the islamic emirate of afghanistan ( [...] religion, the world's earliest monotheistic religion, (meaning a religion believing in one god) lived in the area (somewhere north of today's afghanistan), around 1000 b.c.
ancient history
before the middle of the sixth century bce, afghanistan was held by the medes.
then the achaemenids took over control of the land and made it part of the persian empire. alexander the great defeated and conquered the persian empire in 330 bce. he founded some cities in the area. the people used macedonian culture and language. after alexander, greco-bactrians, scythians, kushans, parthians and sassanians ruled the area.
kushans spread buddhism from india in the 1st century bce, and buddhism remained an important religion in the area until the islamic conquest in the 7th century ce.
the buddhas of bamiyan were giant statues, a reminder of buddhism in afghanistan. they were destroyed by the taliban in 2001. there were international protests. the taliban believe that the ancient statues were un-islamic and that they had a right to destroy them.
medieval history
arabs introduced islam in the 7th century and slowly began spreading the new religion. in the 9th and 10th centuries, many local islamic dynasties rose to power inside afghanistan. one of the earliest was the tahirids, whose kingdom included balkh and herat; they established independence from the abbasids in 820. the tahirids were succeeded in about 867 by the saffarids of zaranj in western afghanistan. local princes in the north soon became feudatories of the powerful samanids, who ruled from bukhara. from 872 to 999, north of the hindu kush in afghanistan enjoyed a golden age under samanid rule.
in the 10th century, the local ghaznavids turned ghazni into their capital and firmly established islam throughout all areas of afghanistan, except the kafiristan region in the northeast. mahmud of ghazni, a great ghaznavid sultan, conquered the multan and punjab region, and carried raids into the heart of india. mohammed bin abdul jabbar utbi (al-utbi), a historian from the 10th century, wrote that thousands of "afghans" were in the ghaznavid army. the ghaznavid dynasty was replaced by the ghorids of ghor in the late 12th century, who reconquered ghaznavid territory in the name of islam and ruled it until 1206. the ghorid army also included ethnic afghans.
afghanistan was recognized as khorasan, meaning "land of the rising sun," which was a prosperous and independent geographic region reaching as far as the indus river.
all the major cities of modern afghanistan were centers of science and culture in the past. the new persian literature arose and flourished in the area. the early persian poets such as rudaki were from what is now afghanistan. moreover, ferdowsi, the author of shahnameh, the national epic of iran, and rumi, the famous sufi poet, were also from modern-day afghanistan. it has produced scientists such as avicenna, al-farabi, al-biruni, omar khayyám, al-khwarizmi, and many others who are widely known for their important contributions in areas such as mathematics, astronomy, medicine, physics, geography, and geology. it remained the cultural capital of pers | 1,024 | 27 |
52 | afghanistan, officially the islamic emirate of afghanistan ( [...] ia until the devastating mongol invasion in the 13th century.
timur, the turkic conqueror, took over in the end of the 14th century and began to rebuild cities in this region. timur's successors, the timurids (1405–1507), were great patrons of learning and the arts who enriched their capital city of herat with fine buildings. under their rule afghanistan enjoyed peace and prosperity.
between south of the hindu kush and the indus river (today's pakistan) was the native land of the afghan tribes. they called this land "afghanistan" (meaning "land of the afghans"). the afghans ruled the rich northern indian subcontinent with their capital at delhi. from the 16th to the early 18th century, afghanistan was disputed between the safavids of isfahan and the mughals of agra who had replaced the lodi and suri afghan rulers in india. the safavids and mughals occasionally oppressed the native afghans but at the same time the afghans used each empire to punish the other. in 1709, the hotaki afghans rose to power and completely defeated the persian empire. then they marched towards the mughals of india and nominally defeated them with the help of the afsharid forces under nader shah afshar.
in 1747, after nader shah of persia was killed, a great leader named ahmad shah durrani united all the different muslim tribes and established the afghan empire (durrani empire). he is considered the founding father of the modern state of afghanistan while mirwais hotak is the grandfather of the nation.
since the 1800s
during the 1800s, afghanistan became a buffer zone between two powerful empires, the british indian empire and the russian empire. as british india advanced into afghanistan, russia felt threatened and expanded southward across central asia. to stop the russian advance, britain tried to make afghanistan part of its empire but the afghans fought wars with british-led indians from 1839 to 1842 and from 1878 to 1880. after the third war in 1919, afghanistan under king amanullah gained respect and recognition as a completely independent state.
the kingdom of afghanistan was a constitutional monarchy established in 1926. it was the successor state to the emirate of afghanistan. on 27 september 1934, during the reign of zahir shah, the kingdom of afghanistan joined the league of nations. during world war ii, afghanistan remained neutral. it pursued a diplomatic policy of non-alignment.
the creation of pakistan in 1947 as its eastern neighbor created problems. in 1973, political crises led to the overthrow of the king. the country's new leader ended the monarchy and made afghanistan a republic. in 1978, a communist political party supported by the soviet union seized control of afghanistan's government. this move sparked rebellions throughout the country. the government asked the soviet union for military assistance. the soviets took advantage of the situation and invaded afghanistan in december 1979.
most people in afghanistan opposed the sudden soviet presence in their country. for nearly a decade, anti-communist islamic forces known as mujahideen were trained inside neighboring pakistan to fight the soviets and the afghan government. the united states and other anti-soviet countries supported the mujahideen. in the long war, over one million afghan civilians were killed. the soviet army also lost more than 15,000 soldiers in that war. millions of afghans left their country to stay safe in neighb | 1,024 | 27 |
52 | afghanistan, officially the islamic emirate of afghanistan ( [...] oring pakistan and iran. in 1989 the soviet army withdrew the last of its troops.
after the soviets left in 1989, the afghan civil war started; different afghan warlords began fighting for control of the country. the warlords received support from other countries, including neighboring pakistan and iran. a very conservative islamic group known as the taliban emerged in an attempt to end the civil war. by the late 1990s the taliban had gained control over 95% of afghanistan. a group known as the northern alliance, based in northern afghanistan near the border with tajikistan, continued to fight against the taliban.
the taliban ruled afghanistan according to their strict version of islamic law. people whom the taliban believed violated these laws were given cruel punishments. in addition, the taliban completely restricted the rights of women. because of such policies, most countries refused to recognize the taliban government. only pakistan, saudi arabia and the united arab emirates (uae) accepted them as the official government.
the taliban also angered other countries by allowing suspected terrorists to live freely in afghanistan. among them were osama bin laden and members of the al-qaeda terrorist network. in september 2001, the united states blamed bin laden for the terrorist attacks on the world trade center in new york city and the pentagon outside washington, d.c. the taliban refused to hand him over to the united states. in response, the united states and its allies launched a bombing campaign against al-qaeda in october 2001. within months the taliban abandoned kabul, and a new government led by hamid karzai came to power, but fighting between the taliban and us-led armies continued. taliban fighters have gone into afghanistan from neighboring pakistan. afghans accuse pakistan's military of being behind the taliban militants but pakistan has rejected this and stated that a stable afghanistan is in pakistan's own interest.
in december 2004, hamid karzai became the first democratically elected president of afghanistan. nato began rebuilding afghanistan, including its military and government institutions. many schools and colleges were built. freedom for women has improved. women can study, work, drive, and run for office. many afghan women work as politicians, some are ministers while at least one is a mayor. others have opened businesses, or joined the military or police. afghanistan's economy has also improved dramatically, and nato agreed in 2012 to help the country for at least another 10 years after 2014. in the meantime, afghanistan improved diplomatic ties with many countries in the world and continues.
in august 2021, the cabinet of afghanistan lost its power. most of the country fell to the taliban on 15 august 2021 with president ashraf ghani escaping the country. as of 18 august 2021, the former government's last remaining holdout is the panjshir valley.
government
since the taliban captured kabul on 15 august 2021, the governance of afghanistan is disputed between the islamic emirate of afghanistan and the islamic republic of afghanistan.
according to transparency international, afghanistan remains in the top most corrupt countries list.
provinces
as of 2004, there are thirty-four provinces. each province is divided into districts. (for cities see list of cities in afghanistan.)
relationship with other countries
russia's ambassador (dmitrij zjirnov) had a meeting with representatives from taliban on 18 august | 1,024 | 27 |
52 | afghanistan, officially the islamic emirate of afghanistan ( [...] 2021; russia's embassy was still in operation (or open).
an "indian [ diplomat or] envoy to qatar" had [at least one] meeting "with taliban leader stanekzai in doha in late august", media said.
a united states "team led by" [then] "deputy special representative tom west and [a] top usaid humanitarian official" had meetings, in qatar in october, with afghanistani officials. women's rights was a subject during the talks.
norway's ambassador visited afghanistan - and had meetings with taliban - during a two-day visit in the middle of january 2022. representatives of the taliban leadership will come to norway and meet diplomats from different countries, during 23.-25. january. also, norway has stopped (as of 2022's first quarter) supporting with money - (to) the authorities of afghanistan, media said. previously, norwegian diplomats had at least two meetings with taliban in doha, in 2021's fourth quarter; there are no political talks yet (as of 2021's fourth quarter); the talks are about humanitarian aid and evacuation.
turkey's foreign minister had a meeting (in turkey) with "a delegation led by" foreign minister of afghanistan, in 2021's fourth quarter.
in russia, a meeting about afghanistan was held on october 20; "the participants [... were] india, usa, afghanistan, china, pakistan, iran and central asian" countries, media said.
diplomatic missions that still represent the islamic republic of afghanistan
the ambassador in oslo, norway does not recognize the taliban-led government (as of 2021's fourth quarter). | 520 | 27 |
53 | Angola, officially the Republic of Angola, is a country in southern Africa. It shares borders with Namibia in the south, the Democratic Republic of the Congo in the north, and Zambia in the east. Its west border touches the Atlantic Ocean. Its coastline is 1600 kilometers. Angola's capital is Luanda. The country has many natural resources. Angola is the seventh largest country in Africa. The capital and most populated city of Angola is Luanda.
Angola is a member state of the African Union, the Community of Portuguese Language Countries, the Latin Union, South Atlantic Peace and Cooperation Zone and the Southern African Development Community.
History
Portugal built up its power in Angola from the late 15th to the middle 20th century.
After independence there was a civil war from 1975 to 2002. Cuba and the Soviet Bloc supported the ruling People's Movement for the Liberation of Angola (MPLA). South Africa supported the insurgent National Union for the Total Independence of Angola (UNITA) until the end of apartheid. The war ended after the rebel leader Jonas Savimbi was killed.
Geography
Angola is the world's twenty-third largest country. Angola is bordered by Namibia to the south, Zambia to the east, the Democratic Republic of the Congo to the north-east, the Republic of the Congo via the exclave of Cabinda, and the South Atlantic Ocean to the west.
Climate
Angola's average temperature on the coast is in the winter and in the summer. It has two seasons; dry (May to October) and hot rainy (November to April).
Demographics
Angola had a population of 25,789,024 in 2014.
Provinces
Angola is divided into eighteen provinces.
See List of settlements in Angola for the cities and towns in the country. | 512 | 0 |
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