AcharyaChanakya/simple-wikipedia huggingface dataset:
Volcanoes are made when two tectonic plates come together. When these two plates meet, one of them (usually the oceanic plate) goes under the continental plate. This is the process of subduction. Afterwards, it melts and makes magma (inside the magma chamber), and the pressure builds up until the magma bursts through the Earth's crust.
The second way is when a tectonic plate moves over a hot spot in the Earth's crust. The hot spot works its way through the crust until it breaks through. The caldera of Yellowstone Park was formed in that way; so were the Hawaiian Islands.
A traditional way to classify or identify volcanoes is by its pattern of eruptions. Those volcanoes which may erupt again at any time are called active. Those that are now quiet called dormant (inactive). Those volcanoes which have not erupted in historical times are called extinct.
An active volcano is currently erupting, or it has erupted in the last 10,000 years. An example of an active volcano is Mount St. Helens in the United States (US).
A dormant volcano is "sleeping," but it could awaken in the future. Mount Rainier in the United States is considered dormant.
in French dormant means en sommeil
An extinct volcano has not erupted in the past 10,000 years. Edinburgh Castle in Scotland sits on top of an extinct volcano.
The Earth's largest volcano has been discovered. It is 2 km below the sea on an underwater plateau known as the Shatsky Rise. This is about 1,600 km east of Japan. The previous record-holder, Mauna Loa in Hawaii, is still the largest volcano on land.
The 310,000 km (119,000 sq mi) volcano, Tamu Massif, is comparable in size to Mars' vast Olympus Mons volcano, which is the largest in the Solar System. It was formed about 145 million years ago when massive lava flows erupted from the centre of the volcano to form a broad, shield-like feature. That suggests the volcano produced a flood basalt eruption.
The Tamu Massif extends some 30 km (18 miles) into the Earth's crust. The researchers doubted the submerged volcano's peak ever rose above sea level during its lifetime and say it is unlikely to erupt again.
The Big Bang is a scientific theory about how the universe started, and then made the stars and galaxies we see today. The Big Bang is the name that scientists use for the most common theory of the universe, from the very early stages to the present day.
The universe began as a very hot, small, and dense superforce (the mix of the four fundamental forces), with no stars, atoms, form, or structure (called a "singularity"). Then about 13.8 billion years ago, space expanded very quickly (thus the name "Big Bang"). This started the formation of atoms, which eventually led to the formation of stars and galaxies. It was Georges who first noted (in 1927) that an expanding universe could be traced back in time to an originating single point. The universe is still expanding today, and getting colder as well.
As a whole, the universe is growing and the temperature is falling as time passes. Cosmology is the study of how the universe began and its development. Some scientists who study cosmology have agreed that the Big Bang theory matches what they have observed so far.
Fred Hoyle called the theory the "Big Bang" on his radio show. He did not believe the Big Bang was correct. Scientists who did not agree with him thought the name was funny and decided to use it.
Scientists base the Big Bang theory on many different observations. The most important is the redshift of very far away galaxies. Redshift is the Doppler effect occurring in light. When an object moves away from Earth, its color rays look more similar to the color red than they actually are, because the movement stretches the wavelength of light given off by the object. Scientists use the word "red hot" to describe this stretched light wave because red is the longest wavelength on the visible spectrum. The more redshift there is, the faster the object is moving away. By measuring the redshift, scientists proved that the universe is expanding, and they can work out how fast the object is moving away from the Earth. With very exact observation and measurements, scientists believe that the universe was a singularity approximately 13.8 billion years ago. Because most things become colder as they expand, scientists assume that the universe was very small and very hot when it started.
Other observations that support the Big Bang theory are the amounts of chemical elements in the universe. Amounts of very light elements, such as hydrogen, helium, and lithium seem to agree with the theory of the Big Bang. Scientists also have found "cosmic microwaves background radiation". This radiation is known as radio waves, and they are everywhere in the universe. This radiation is now very weak and cold, but a long time ago it was very strong and very hot.
It can be said that time had no meaning before the Big Bang. If the Big Bang was the beginning of time, then there was no universe before the Big Bang, since there could not be any "before" if there was no time! Other ideas state that the Big Bang was not the beginning of time 13.8 billion years ago. Instead, some believe that there was a completely different universe before the Big Bang, and it may have been very different from the one we know today.
Nonetheless, in November 2019, Jim Peebles, awarded the 2019 Nobel Prize in Physics for his theoretical discoveries in physical cosmology. noted, in his award presentation, that he does not support the Big Bang Theory, due to the lack of concrete supporting evidence, and stated, "It's very unfortunate that one thinks of the beginning whereas in fact, we have no good theory of such a thing as the beginning."
Many things happened in the first picosecond of the universe's time:
Gmail is a free e-mail service that is run by Google. It can be accessed on the web, by POP3, or by IMAP. Some of the competitors to Gmail are Yahoo! Mail, Hotmail/Windows Live Mail, and Inbox.Com. The space given to any Gmail member is increased a small amount every second, and as of July 26, 2012, Google provides each account with about 10272 MB of space.
Google Apps is a service from Google that was created in February 2006 as Gmail for your domain. It is to allow system administrators of a company or organisation to create email accounts for their own domain.
In the United Kingdom (UK), the trademark "Gmail" was owned by another company before Gmail by Google was started. Thus, the United Kingdom uses a domain of "googlemail.com" for their users, and the logo has the words of "Google Mail" instead of the normal "Gmail".
In September 2009 Google began to change the branding of UK accounts back to Gmail following the resolution of the trademark dispute.
Astronomer
Analysis is the process of breaking a complex topic or substance into smaller parts to gain a better understanding of it. The technique has been applied in the study of mathematics and logic since before Aristotle (384–322 B.C.), though "analysis" as a formal concept is a relatively recent development.
The word comes from the Ancient Greek ἀνάλυσις ("analusis", "a breaking up", from "ana-" "up, throughout" and "lysis" "a loosening").
In this context, Analysis is the opposite of synthesis, which is to bring ideas together.
The following concepts are closely related to this basic idea:
Foolishness is when someone acts without wisdom or sense. A foolish decision is one made without careful reasoning or judgement. An act of foolishness is called folly. A person who shows foolishness may be called a fool. It is different to stupidity, which is the lack of intelligence.
A "fool's errand" is a useless piece of work.
A "fool's paradise" a happy state for which there is no good reason.
The "wise fool" is a common literary character, a person who appears at first to be unintelligent but then reveals him or herself to possess a grest deal of wisdom. An example of this is Sancho Panza in Cervantes' "Don Quixote". Sancho is an uneducated peasant who at first seems to have little sense or experience. However, as the tale unfolds, he reveals himself to possess a wealth of common sense, first expressed through endless proverbs, but then through his own skill. In this sense he provides a comic juxtaposition to Quixote himself, who is highly educated but insane; both of them supply what the other lacks.
Aristotle (Stagira, Macedonia, 384 – Chalicis, Euboea, Greece, 7 March 322 ) was a Greek philosopher. He was one of the most important philosophers in the history of Western civilization. It is said that Aristotle wrote many books, but only a much smaller number survive. Aristotle was the boyhood tutor of Alexander the Great, who later sent him plants and animals from parts of his new empire.
Aristotle's father, Nicomachus, was a soldier of King Amyntas of Macedonia. From his eighteenth to his thirty-seventh year, Aristotle lived in Athens, as a metic and student of Plato.
At about the age of eighteen, he went to Athens to continue his education at Plato's Academy. Aristotle remained at the academy for nearly twenty years, not leaving until after Plato's death in 347 BC. He then traveled with Xenocrates to Asia Minor. While in Asia, Aristotle traveled with Theophrastus to the island of Lesbos, where they researched the botany and zoology of the island. Soon after Hermias' death, Aristotle was invited by Philip II of Macedon to become the tutor to his son Alexander the Great in 343 B.C.
Aristotle was appointed as the head of the royal academy of Macedon. During that time he gave lessons not only to Alexander, but also to two other future kings: Ptolemy and Cassander. Aristotle encouraged Alexander toward eastern conquest, and his attitude towards Persia was ethnocentric. In one famous example, he advises Alexander to be 'a leader to the Greeks and a despot to the barbarians, to look after the former as after friends and relatives, and to deal with the latter as with beasts or plants'.
By 335 he had returned to Athens, starting his own school there known as the Lyceum. Aristotle taught courses at the school for the next twelve years. It is during this period in Athens from 335 to 323 when Aristotle is believed to have written many of his works. Aristotle wrote many dialogues, only fragments of which survived. The works that have survived are in fairly rough form. They are generally thought to be lecture notes for his students.
Aristotle's combined works constitute a virtual encyclopedia of Greek knowledge. It has been suggested that Aristotle was probably the last person to know everything there was to be known in his own time.
Near the end of Alexander's life, he began to suspect plots, and threatened Aristotle in letters. Aristotle was vocal about his dislike for Alexander's claim of divinity, and the king executed Aristotle's grandnephew Callisthenes as a traitor. Alexander died in Babylon in 323 without ever having returned to his native land. Upon Alexander's death, anti-Macedonian sentiment in Athens once again flared up, and Aristotle fled the city. However, he died in Euboea of natural causes that same year, 322 .
The three greatest ancient Greek philosophers were Aristotle, Plato, and Socrates. Socrates taught Plato, then Plato taught Aristotle. These three thinkers turned early Greek philosophy into the beginnings of Western philosophy as it is today. Aristotle taught Alexander the Great, who later conquered the entire Middle East.
Plato's main ideas were that knowledge from the senses was always confused and not pure. True knowledge can be gotten from the thinking soul that turns away from the world. Only the soul can have knowledge of "Forms", the real way things are. The world is only a copy of these "Forms" and is not perfect.
Aristotle thought differently. He thought that knowledge from the senses was more important. These thoughts became some of the roots of the scientific method after hundreds of years. Most of the things Aristotle wrote that we still have today are notes from his speaking and teaching. Some of his important writings are "Physics", "Metaphysics", "(Nicomachean) Ethics", "Politics", "De Anima (On the Soul)", and "Poetics".
He also had problems with the atomic theory. He did not believe in Democritus' theories about the atomic theory. He believed that all matter was continuous whereas Democritus stated the all matter was made up of tiny indivisible things called "atoms". Democritus was proved right by physicist John Dalton in 1804.
Aristotle created a form of logic. His logic is called "sentential logic" because it uses sentences for the syllogism.
Aristotle's logic influenced the history of Western thought. It was Aristotle's logic which was copied and used in the Arabic and Latin mediaeval traditions. It was dominant for two and a half thousand years, until the late 19th century. Then modern logic was started by Gottlob Frege, Charles Sanders Peirce and others.
Aristotle is the earliest natural historian whose work has survived in some detail. He certainly did research on the natural history of Lesbos, and the surrounding seas and neighbouring areas. The works "History of Animals", "Generation of Animals" and "Parts of Animals" have observations and interpretations, along with some myths and mistakes.
The most striking passages are about the sea-life round Lesbos. As well as live observation, he got specimens from the catches of fishermen. His observations on catfish, electric fish ("Torpedo") and angler-fish are detailed. His writing on cephalopods such as "Octopus", "Sepia" (cuttlefish) and the paper nautilus ("Argonauta argo") are accurate. His description of the hectocotyl arm, used in sexual reproduction, was widely disbelieved until its rediscovery in the 19th century. He separated the aquatic mammals from fish, and knew that sharks and rays were part of the group he called Selachē (Selachimorpha).
Another good example of his methods comes from the "Generation of Animals" in which Aristotle describes breaking open fertilized chicken eggs at intervals to observe when visible organs were generated.
He gave accurate descriptions of ruminants' four-chambered fore-stomachs, and of the ovoviviparous egg development of the houndshark "Mustelus mustelus".
The works are traditionally listed in this sequence:
Aristotle is still one of the most influential people who ever lived. He contributed to almost every kind of knowledge in his day, and he started many new fields.
Aristotle was the founder of formal logic, pioneered the study of zoology, and helped to develop scientific method.
Despite these achievements, Aristotle's errors are thought by some, such as Peter Medawar, to have held back science considerably. Bertrand Russell notes that "almost every serious intellectual advance has had to begin with an attack on some Aristotelian doctrine". Russell also refers to Aristotle's "Ethics" as "repulsive", and calls his logic "as definitely antiquated as Ptolemaic astronomy". Russell says these errors make it difficult to do historical justice to Aristotle, until one remembers what an advance he made on his predecessors.
The immediate influence of Aristotle's work was felt as the Lyceum grew into the Peripatetic school of philosophers. Aristotle's influence over Alexander the Great is seen in the latter's bringing with him, on his expedition, biologists and researchers.
Carl Edward Sagan (November 9, 1934 - December 20, 1996) was an American astronomer. He was very interested in what life on other planets would be like, which is known as SETI (search for extraterrestrial intelligence).
Sagan was a science communicator, which meant he taught people about science. He felt like the general public was losing interest in science, so he wrote many books and appeared on television to make it popular again. He mostly talked about planetary science and topics related to space. One of his most famous works includes. "Cosmos: A Personal Voyage. Cosmos" was a television series about many different scientific topics, which Sagan co-wrote and narrated. It made him very famous outside the world of science.
Sagan supported the scientific method and scientific skepticism.
Carl Sagan was born in Brooklyn, New York City. Carl's family was Jewish. His father, Samuel Sagan, was an immigrant from the Russian Empire. Samuel was born in 1905 in a city called Kamianets-Podilskyi. The Russian Empire no longer exists, so today Kamianets-Podilskyi is in Ukraine. Samuel made clothes for a living. Carl's mother, Rachel Molly Gruber, was a housewife. Carl had a sister named Carol, who became a social worker. Carl was named after his grandmother, Chaiya (Clara).
Sagan attended the University of Chicago earning two degrees in physics. He followed with a doctorate in Astronomy in 1960 and taught at Harvard University until 1968, when he moved to Cornell University.
Sagan became a teacher and director at Cornell in 1971. He helped many unmanned spacecraft to explore outer space. He thought of the idea of putting a message on spacecraft which could be understood by any life from another planet that might find it. The first message sent into space was a large gold-plated label on the space probe Pioneer 10. He continued to make the messages better. The last message he helped with was the Voyager Golden Record that was sent out with the Voyager space probes.
He was well known as a writer who warned of the dangers of nuclear winter. He helped people learn about the atmosphere of Venus, seasonal changes on Mars, and Saturn's moon Titan. He showed that the atmosphere of Venus is very hot and dense. He also said that global warming was a growing, man-made danger like the natural development of Venus into a hot and dangerous planet with greenhouse gases. He suggested that the seasonal changes on Mars were due to dust storms.
Sagan was among the first to guess that Titan and Jupiter's moon Europa might have oceans or lakes, which means that life could be there. Europa's underground ocean was later confirmed by the spacecraft Galileo.
Sagan thought the search for life on other planets was a good idea. He said scientists should listen with large radio telescopes for signals from other planets. He thought sending probes to other planets was a good idea. Sagan was editor "Icarus" (a magazine about space exploration) for 12 years. He helped start the "Planetary Society" and was a member of the SETI Institute Board of Trustees.
Sagan also believed that the Drake equation suggested that many kinds of intelligent life could form, but that the lack of evidence (the Fermi paradox) suggests that intelligent beings destroy themselves rather quickly. This made him keen to talk about ways that humanity could destroy itself, in the hope of avoiding such destruction.
Under the name "Mr. X," Sagan wrote about pot smoking in the 1971 book "Reconsidering Marijuana". Lester Grinspoon (the book's editor), told this to Keay Davidson, Sagan's biographer. Sagan said that marijuana helped him write some of his books.
Sagan was very good at helping people to understand the cosmos. He gave the 1977/1978 Christmas Lectures for Young People at the Royal Institution. He wrote (with Ann Druyan, who became his third wife) and made the very popular thirteen-part PBS television series ""; he also wrote books to help science become more popular ("The Dragons of Eden", which won a Pulitzer Prize, "Broca's Brain", etc.) and a novel, "Contact", that was a best-seller and was made into a film starring Jodie Foster in 1997. The film won the 1998 Hugo Award.
After "Cosmos", Sagan was linked with the catchphrase "billions and billions", which he never used in the television series (but he often used the word "billions"). He wrote "Pale Blue Dot: A Vision of the Human Future in Space", which was chosen as a notable book of 1995 by The "New York Times".
Not all scientists agreed with him. Although they all liked the way he made science popular, some were afraid that people would think that his personal opinions might be confused with real science. What he said about the Kuwait oil well fires during the first Gulf War were shown later to be wrong.
Later in his life, Sagan's books showed his skeptical, naturalistic view of the world. In his book "The Demon-Haunted World", Sagan gave a list of mistakes he had made as an example of how science is self-correcting. The compilation "Billions and Billions: Thoughts on Life and Death at the End of the Millennium", published after Sagan's death, contains essays written by Sagan, such as his views on abortion, and Ann Druyan's account of his death as a non-believer.
After a long and difficult fight with myelodysplasia, Sagan died of pneumonia at the age of 62, on December 20, 1996, at the Fred Hutchinson Cancer Research Center in Seattle, Washington. Sagan was very important, because he made science popular, and changed the way science was organized, and because he defended humanism, and argued against seeing things from only one point of view.
The landing site of the unmanned Mars Pathfinder spacecraft was renamed the "Carl Sagan Memorial Station" in honor of Dr. Sagan on July 5, 1997. Asteroid 2709 Sagan is also named in his honor.
The 1997 movie "Contact" (see above), based on Sagan's novel of the same name, and finished after his death, ends with the dedication "For Carl."
Matsuo Munefusa, known as Matsuo Bashō (, 1644 - November 28, 1694) was a Japanese poet. He is known as the greatest maker of haiku, a kind of poetry with 17 syllables. The Japanese written language was difficult to master, but haiku was easy for him to write. Matsuo's haikus included characteristics of nature and the four seasons. The reader has to use their imagination to understand his poems.
According to Japanese custom, he is usually called "Basho" without his family name, and his signature as a poet does not include his house name. He signed usually "はせを". He is one of the greatest writers of the Edo period, and he raised the haiku form to its highest level.
He was born in Iga, now a part of Mie prefecture in a samurai (Japanese warrior) family. After many years of samurai life he found that poetry would be his life work, and gave up being a samurai. He started his life as a poet when he served his lord as a samurai. Matsuo became educated in classical Japanese poems. First he named himself "Tosei" (桃青) meaning "unripe peach in blue". Basho took this name because he admired a Chinese poet, Li Po whose name means "plum in white".
He quit samurai life 1666, and in 1675 he moved to Edo, today called Tokyo. There, in 1678, he got to be a haiku master (""Sosho"") and began the life of a working poet. In 1680, he moved to Fukagawa, where he had a house. This was just outside of Edo. One of his followers gifted him a banana plant ("basho-an"). He planted the plant and called himself "Basho" because it became his favorite tree in his garden.
In his life, Basho visited many places. Those travels were important for his writings. He visited his disciples (followers) and taught them by making "renga", a series of haiku, with them. He also visited famous places in Japanese history. These visits made his writing much stronger.
His most famous book is "Oku no Hosomichi" ("The Narrow Road Through the Deep North"). This book was written after a trip. On the trip, Basho and his disciple left Edo on March 24, 1689. They went around Tohoku and Hokuriku, and returned to Edo in 1691. The trip in this book ends in Ogaki, Mino (Gifu prefecture today) with one of his haiku where he hinted that he wanted to visit Ise shrine after staying in Ogaki. Matsuo was considered to have written some of the most beautiful travel diaries ever written in Japanese.
Basho died because of disease in early autumn of 1694 in Osaka, while staying at a house of his disciple on a trip. Before his death, he made a haiku as his last words:
Colonization is the act of one country settling another place, in order to become the new rulers of the new country, and to live in the new country. An early example is the settlers who went from the cities of Ancient Greece to start new cities.
In 1492, Christopher Columbus landed in The Americas. This is how the Europeans learned that North America and South America were there. The Europeans colonized the Americas. Because of this, and the killing of lots of Native Americans, most people now living in North America are the descendents of Europeans.
Sometimes, science fiction stories talk about humans colonizing outer space on space stations or planets other than Earth. Some science fiction stories like The Matrix speak of the robots the human beings made, taking over, and colonizing Earth.
Choreography (dance-writing) is the art of making dances. It tells dancers how they should dance and move. The word has been used since the late 18th century to mean the art of composing dance.
A person who does choreography is called a "choreographer". A choreographer makes a dance based on music or a synopsis (a writing of what occurs in the dance). They may also act as trainers for professional dancers in ballet, stage shows and competitive ballroom dance. Their ideas may be recorded in dance notation, or on videos.
Choreography is also used in other types of performances. In Ice skating and Ice dancing, the choreographer designs the moves the skates does. In theater, movies and television, a choreographer is used to design fight scenes. For example, Bob Anderson designed many of the sword fight scenes in the "Lord of the Rings" movies as well as some of the "Star Wars" movies. A person who does this type of choreography is usually called a "fight choreographer".
Electrical cell
An electrical cell is a device used to generate electricity, or to make chemical reactions by applying electricity. A battery is one or more cells, connected. This cell is also known as electrochemical cell.
The simple electrical cells were first developed in 1800s. They are also called "galvanic cells", because an Italian scientist named Luigi Galvani invented these cells.
Special chemical reactions which occur inside the electrical cell, result in oxidation and reduction of the substances inside the cell. This produces electrical energy. Normal batteries work like this.
Some electrical cells produce electricity without using chemical energy. For example, solar cells produce electricity when they are exposed to sun light.
A plate of zinc and a plate of copper immersed in a dilute solution which contains acid or salt is an example of the chemical reaction based cell. The solution acts as an electrolyte (electric conductor). When the two plates are connected to a current meter with a wire, electric current will pass; this is because oxidation and reduction processes take place in this chemical reaction turning the zinc plate to a negative electrode and the copper plate to a positive electrode, and so the electrons flow from zinc to copper.
Some chemical reactions need high energy to happen. An example is the breakdown of water into hydrogen and oxygen. An electrical cell (or an "electrolytic cell") is used for these reactions. It is a container which has to have a chemical reaction involving electrodes. The chemical substances are exposed to electrical power, and the electrolysis reaction happens inside the electrical cell.
Two pieces of metal are placed in water that has a little electrolyte such as hydrochloric acid, sulfuric acid, sodium bicarbonate, or sodium hydroxide added to it. An electric current is applied and gas comes out of each electrode. Some greenish-brown color may be seen too if iron was used.
There may also be a chemical reaction which will result in the explosion of the iron and has a strong blast radius (safety goggles recommended).
Dry cell
Dry cells are a type of chemical cells. Dry cells are commonly used today in the form of batteries. Dry cells are used in many electrical appliances.
Primary cells are not rechargeable. They have to be thrown away after their chemicals are used.
Secondary cells are rechargeable. They can be used again.
The Vietnam War (also known as Second Indochina War or American War in Vietnam) lasted from 1 November 1955–30 April 1975, (19 years, 5 months, 4 weeks and 1 day). It was fought between North Vietnam and South Vietnam. North Vietnam was supported by the Soviet Union, China and North Korea, while South Vietnam was supported by the United States, South Korea, Thailand, Australia, New Zealand, and the Philippines. People from other countries also went to fight but not in their own national army. This conflict between communist and capitalist countries was part of the Cold War.
The Viet Cong (also known as the National Liberation Front, or NLF), was a South Vietnamese communist force helped by the North. It fought a guerrilla war against the anti-communist forces in the South. The People's Army of Vietnam (also known as the North Vietnamese Army) engaged in a more conventional war, at times putting large forces to battle.
The Vietnam War was very controversial, especially in the United States, and it was the first war to feature live television coverage. It was also the first major armed conflict that the United States lost. The war became so unpopular in the United States that President Nixon eventually agreed to send American soldiers home in 1973.
France began to colonize Vietnam between 1859 and 1862, when they took control of Saigon. By 1864 they controlled all of Cochinchina, the southern part of Vietnam. France took control of Annam, the large central part of Vietnam, in 1874. After France defeated China in the Sino-French war (1884–1885), they took over Tonkin, the northern part of Vietnam. French Indochina was formed in October 1887 from these three areas of Vietnam (Cochinchina, Annam and Tonkin), as well as the Kingdom of Cambodia. Laos was added after a war with Thailand, the Franco-Siamese War, in 1893.
During World War II, after Nazi Germany defeated the French in 1940, French Indochina was controlled by the Vichy French government, a puppet government approved by Nazi Germany. In March 1945 Imperial Japan launched the Second French Indochina Campaign. Japan occupied Indochina until their surrender in August 1945.
After the defeat of Nazi Germany, the Vichy government was no longer in control of France or its territories. The newly formed Provisional Government of the French Republic attempted to take back control of its former colonies in Indochina by force if necessary. But the French efforts at regaining their colony in Vietnam were opposed by a Vietnamese army called the Viet Minh.
The Viet Minh had been founded in 1941 by the communist party and was led by Hồ Chí Minh. This led to the First Indochina War between France and the Viet Minh. The fighting started with the French bombardment of Haiphong Harbor in November 1946 and ended with a triumph of the Viet Minh at Dien Bien Phu.
In July 1954, France and the Viet Minh signed the Geneva Peace Accord. This resulted in dividing Vietnam along the 17th parallel into a northern section, under the control of the communists led by Ho Chi Minh as president, and a southern section led by the Catholic anti-communist Ngo Dinh Diem. The partition was to be temporary until elections in 1956. However, Diem started arresting suspected communist sympathizers in 1956 to keep power for himself. The elections were never held, and in 1957 the north Vietnamese began guerrilla warfare against the south.
The United States supported the anti-communist government in South Vietnam. It began to send military advisors to help train and support the South Vietnamese army. The South was fighting against the Viet Cong, a communist party based in South Vietnam which was allied with North Vietnam. The Viet Cong began a campaign of assassination in 1957. In 1959, North Vietnam dramatically increased its military assistance to the Viet Cong, which then began attacking South Vietnamese military units. In the American domino theory they feared that if communism took hold in Vietnam, it would spread to other countries nearby.
On 2 August 1964, the destroyer USS "Maddox" was in the Gulf of Tonkin, on an intelligence mission along North Vietnam's coast. The US said that three North Vietnamese torpedo boats attacked the destroyer. The Maddox fired back and damaged the three torpedo boats. The US then claimed that two days later, the torpedo boats again attacked the "Maddox" and the destroyer USS "Turner Joy". In this second attack the US ships did not actually see the torpedo boats, but said they had found them using the ship's radar.
After the alleged second attack the U.S. launched air strikes against North Vietnam. The Congress passed the Gulf of Tonkin Joint Resolution (H.J. RES 1145) on 7 August 1964. This gave the president the power to run large-scale military operations in Southeast Asia without declaring war. There was little to no proof of these attacks and it was believed by some that they were an excuse for expanded U.S. involvement in Indochina.
The North Vietnamese and Viet Cong were supplied by a vast network of hidden trails, known as the Ho Chi Minh Trail. Which was hidden very well and many attempts were made by the U.S. to bomb and destroy it. Supplies and soldiers from North Vietnam were sent through Laos to communists forces in South Vietnam. American planes heavily bombed the Ho Chi Minh Trail; of bombs were dropped on Laos. It slowed down but did not stop the trail system.
Severe communist losses during the 1968 Tet Offensive, made it possible for the U.S. to withdraw many soldiers. As part of a policy called "Vietnamization", South Vietnamese troops were trained and equipped to replace the Americans who left. By 1973, 95 percent of the American troops were gone.
A peace treaty was signed in Paris in January 1973 by all the parties, but fighting continued until 1975.
There were some large-scale battles during the Vietnam War however most of the fighting was guerilla warfare. This type of warfare is different from the large-scale battles fought between armies, like those in World War II.In guerilla warfare, small units fight limited battles against an enemy force, set up ambushes, make surprise attacks, and then retreat back into the countryside or blend into the local population. It also includes making it difficult for the enemy to operate by engaging in sabotage and harassing the enemy with lethal means such as land mines and booby traps. The communist troops more often engaged in guerilla warfare against the South Vietnamese and American troops.
Although most traps were non-explosive, there were a few explosive traps which all used grenades. A trip wire was placed and if a soldier tripped over the wire, a grenade pin was pulled out and the grenade would blow, killing the soldier.
Another style of trap was nicknamed “Venus Flytrap”. It had about eight barbs attached to a rectangular frame sitting on a small hole. The barbs were facing down so when the soldier’s leg got caught in it, it wouldn’t hurt until he pulled his leg out. When he pulled his leg out the barbs would rip through his leg.
Another Vietcong trap was the Punji trap. Two wooden platforms were placed and covered with leaves to camouflage it. There were spikes on the inside of the wood. When a soldier came along and walked on the wood, it caved in and the spikes would go through the soldier’s foot. These traps were the most common because they were the cheapest and very effective. They also were often contaminated (often with feaces) so that the soldier would also become infected.
Besides hurting or killing people, these traps were good at causing fear and lowering soldier morale.
The Fall of Saigon was the capture of Saigon, the capital of South Vietnam, by the People's Army of Vietnam and the National Liberation Front on April 30, 1975. This marked the end of the Vietnam War and the beginning of the formal reunification of Vietnam into a communist state.
Before the city fell the few American civilian and military personnel left Vietnam, along with tens of thousands of South Vietnamese soldiers and civilians had fled.
North Vietnamese forces under the command of General Văn Tiến Dũng began their final attack on Saigon, which was commanded by General Nguyen Van Toan on April 29, with a heavy artillery bombardment of Tân Sơn Nhứt Airport which killed the last two American servicemen who died in Vietnam, Charles McMahon and Darwin Judge.
By the afternoon of the next day, North Vietnamese troops had occupied the important points within the city and raised their flag over the South Vietnamese presidential palace. The government of South Vietnam formally gave up shortly after.
Saigon was renamed Ho Chi Minh City, after communist leader Ho Chi Minh.
Any Americans that were in Saigon at the time were evacuated by helicopter or fixed-wing aircraft. The surrender of Saigon was told by the South Vietnamese president himself, General Duong Van Minh. He said "We are here to hand over to you the power in order to avoid bloodshed." General Minh had become South Vietnam’s president for two days as the country crumbled.
The Sahel is a narrow belt of land in North Africa. It is a strip of land about 5500 kilometers long and 450 kilometres wide. It lies at the southern edge of the Sahara Desert
The Sahel has a tropical semi-arid climate. It is between the dry desert land to the north and the forest areas to the south. The temperature is high throughout the year. There is little rainfall in the Sahel (between 100-150 mm and 600mm). It comes during summer months and may be unreliable. It may be very dry in some years, especially if a large area of low pressure, which brings rain, is not carried North over the Sahel by strong winds.
The Sahel is the Arabic word for 'edge' or 'shore'.
The Sahel is facing a big problem, desertification.
The distribution of rainfall in the Sahel region is uneven. The rainfall in the region has been below average since 1970. The Sahel is becoming drier on the whole. The problem of drought affects most of the countries in the Sahel. As a result, crops and animals die. There is no vegetation to protect the soil, which is then removed by flash floods and strong wind. This leads to soil erosion. Finally, the desert spreads towards the surrounding areas.
With better medical services, the birth rate increases and the death rate decreases in the Sahel. As a result, the population in the Sahel is growing. To meet the ever-increasing demand for firewood, a lot of trees have been cut down. More land has become barren. This is called deforestation.
Furthermore, people farm intensively in order to grow more crops, the soil becomes infertile with a lack of nutrients. If this process continues for a long time, no crops can be grown. This is called overcultivation.
People keep animals for food due to the lack of good soil, the animals will have to eat grass and etc. But as the animals eat the grass, they also dug up the soil. As people keep too many animals, the demand for grass is too great. Soil erosion is caused while the animals keep digging the soil up as they eat, and the wind and rain blow away the soil. This process is called overgrazing.
Modern solutions can be used to give a better agricultural result in the Sahel. We can try drip irrigation or hybrid. We should stop using excessive water and consider our actions, to save the Sahel and lake Chad before it is too late.
Chemical change
A chemical change (chemical reaction) is a change of materials into other materials with different properties.
Chemical changes occur when a substance combines with another to form a new substance, or, chemical decomposition into two or more different substances. These processes are called chemical reactions.
Burning of wood is a chemical change as new substances which cannot be changed back (e.g. carbon dioxide) are formed. For example, if wood is burned in a fireplace, there is not wood anymore but ash. Other examples include burning of a candle, rusting of iron, baking a cake, etc. Special details that describe how a chemical change takes place are called chemical properties.
Compare: physical change. The opposite of a chemical change is a physical change. Physical changes are a change in which no new substances are formed, and the substance which is changed is the same. For instance, if a stick of wood is broken, there is still a stick of wood; it is just broken.
More examples include changes of shape, changes of states, passing electricity through a copper wire, breaking of wood, shattering of glass, pouring of water, etc. Special details which do not change in a substance without new substances being formed are called physical properties.
Physical change
A physical change is a type of change in which the form of matter is altered but one substance is not transformed into another. The size or shape of matter may be changed, but no chemical reaction occurs.
All physical changes are reversible and their mass does not change. Some examples are changes of shape, changes of states, and passing electricity through a copper wire. Physical changes could be: melting, freezing, boiling/evaporating, condensing, deposition and sublimation.
Many physical changes also involve the rearrangement of atoms most noticeably in the formation of crystals. Many chemical changes are irreversible, and many physical changes are reversible, but reversibility is not a certain criterion for classification. Although chemical changes may be recognized by an indication such as odor, color change, or production of a gas, every one of these indicators can result from physical change.
Ronald Wilson Reagan (; February 6, 1911 – June 5, 2004) was an American actor and politician who served as the 40th President of the United States from January 20, 1981 to January 20, 1989. He was the 33rd Governor of California from 1967 to 1975. Reagan was the 9th and 13th President of the Screen Actors Guild, from 1947 to 1952 and again from 1959 to 1960. Reagan was a movie, television and radio actor before he began his career in politics.
Reagan was born in Tampico, Illinois. Reagan had a successful career in Hollywood. He was in fifty-three movies. He married actress Jane Wyman in 1940. The couple divorced in 1949. They had three children. Reagan then married Nancy Davis in 1952. They had two children. Their marriage lasted until Reagan's death in 2004.
Before winning his presidental election in 1980, Reagan ran for president two times in 1968 and in 1976. He was re-elected in 1984 at the age of 73, making him the second oldest person elected president of the United States after Joe Biden who was elected in 2020 at the age of 77. He is known as the "Great Communicator" because he was a good public speaker. Reagan was also known as the "Teflon president" because any criticism or scandals against him never stuck or affected his popularity. Reagan still remains one of the most popular presidents in American history because of his optimism for the country. Reagan was the first president of the United States to have been divorced.
Reagan was inaugurated in January 1981. As president, Reagan helped create a new political and economic idea. He created the supply-side economic policies. It was later called Reaganomics. Reagan's economic policy lowered tax rates. It created an economic growth and lowered inflation. In his first term he also survived an assassination attempt. Reagan also declared a War on Drugs. Reagan ordered an invasion of Grenada to end a Communist coup.
Reagan bombed Libya in 1986 trying to kill colonel Muammar al-Gaddafi but failed. President Reagan criticised the Libyan leader's support for terrorist groups and revolutionaries. And he coined a nickname for him: the "mad dog of the Middle East."
He was re-elected in a landslide victory in 1984. During his second term, Reagan worked on ending the Cold War. He also ordered the 1986 bombing of Libya. In 1987, the Reagan administration faced a political scandal. It was the Iran–Contra affair. Reagan worked with Soviet General Secretary Mikhail Gorbachev during his second term. This led to the signing of the INF Treaty. It decreased nuclear weapons in the United States and the Soviet Union. Reagan left office in January 1989.
Reagan was originally a Democrat. In 1962 he changed to the Republican party. He is ranked high in presidential opinion polls.
Reagan died on June 5, 2004 at his Bel Air, Los Angeles home from pneumonia after a ten-year battle with Alzheimer's disease. He was 93 years old.
Reagan was born to Jack and Nelle Reagan on February 6, 1911 in a small apartment building in Tampico, Illinois. He had an older brother named Neil. His father was a Roman Catholic of Irish descent. His mother was a Protestant of English and Scottish descent.
The family moved to different places in Illinois when Reagan was a child. They moved to Monmouth, Galesburg, and Chicago. His family finally settled in Dixon, Illinois. They lived in a small house in Dixon. His family was very poor. Reagan did not have much as a child. In high school, Reagan enjoyed acting. Reagan was athletic. He became a lifeguard and saved 77 lives.
Reagan graduated from Eureka College in 1932. He became a sports announcer at news radio station WHO. Reagan was also a broadcaster for the Chicago Cubs. He was good at recreating baseball games. He made them interesting. At this time, the radio station would get only the scores. He was fired for not mentioning the show's sponsors. Reagan was soon re-hired. Station executives could not find anyone as capable as Reagan to re-create baseball games.
His first screen credit was the starring role in the 1937 movie "Love Is on the Air". He then starred in many movies such as "Dark Victory" with Bette Davis and Humphrey Bogart. Before the movie "Santa Fe Trail" with Errol Flynn in 1940, he played the role of George "The Gipper" Gipp in the movie "Knute Rockne, All American". From his role in the movie, he got the lifelong nickname "the Gipper". In 1941, experts voted him the fifth most popular star from the younger generation in Hollywood.
Reagan's favorite acting role was as a double amputee in 1942's "Kings Row". In the movie, he says the line, "Where's the rest of me?" It was later used as the title of his 1965 autobiography. Many movie critics thought "Kings Row" to be his best movie. Even though the movie was popular, it received bad reviews by "New York Times" critic Bosley Crowther.
Although Reagan called "Kings Row" the movie that "made me a star", he was unable to keep up on his success. This was because he was ordered to active duty with the U.S. Army at San Francisco two months after the movie's release.
During World War II, Reagan was separated for four years from his movie career. He served in the First Motion Picture Unit. After the war, Reagan co-starred in such movies such as in, "The Voice of the Turtle", "John Loves Mary", "The Hasty Heart", "Bedtime for Bonzo", "Cattle Queen of Montana", "Juke Girl", "This Is the Army", "The Winning Team", "Tennessee's Partner", and "Hellcats of the Navy", in which he worked with his wife, Nancy. Reagan's last movie was a 1964 movie "The Killers". Throughout his movie career, his mother, Nelle, often answered much of his fan mail.
Reagan was also a spokesperson. He hosted the "General Electric Theater" since it was first shown in 1953. He was fired in 1962.
Reagan was first elected to the board of directors of the Screen Actors Guild in 1941. After World War II, he quickly returned to Screen Actors Guild. Reagan became the 3rd vice-president of the Screen Actors Guild in 1946.
Reagan was nominated in a special election to become president of the Screen Actors Guild. Reagan was elected in 1947. Reagan was re-elected president in 1959. He served only a year before resigning in 1960.
Reagan led the Screen Actors Guild through labor disputes, the Taft–Hartley Act and the House Un-American Activities Committee (HUAC) hearings and the Hollywood blacklist era.
During the late 1940s, Reagan and his then-wife Jane Wyman gave the FBI names of actors whom they believed were communists. Reagan even spoke at a special meeting at Congress on communism in Hollywood as well.
Despite not supporting giving out names of actors who were suspected communists. Reagan said:
Reagan was very active in politics near the end of his acting career. Reagan used to be a Democrat. He strongly supported the New Deal. He admired Franklin D. Roosevelt. Over time, Reagan became a conservative Republican. This was because he felt the federal government had too much power and authority. He made a famous speech speaking out against socialized medicine (government run health care).
Reagan endorsed Dwight D. Eisenhower and Richard Nixon for the United States presidency. The last time Reagan supported a Democrat was when Helen Gahagan Douglas ran for the United States Senate.