the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
Some bacteria developed photosynthesis, which lets plants make food from the Sun's light and water.
This released a lot of oxygen, which was first taken up by iron in solution.
Eventually, free oxygen got into the atmosphere or air, making Earth's surface suitable for aerobic life (see Great Oxygenation Event).
This oxygen also formed the ozone layer which protects Earth's surface from bad ultraviolet radiation from the Sun.
Complex life on the surface of the land did not exist before the ozone layer.
Earth's land and climate has been very different in the past.
About 3 to 3.5 million years ago almost all land was in one place.
This is called a supercontinent.
The earliest known supercontinent was called Vaalbara.
Much later, there was a time (the Cryogenian) when Earth was almost entirely covered by thick ice sheets (glaciers).
This is discussed as the Snowball Earth theory.
What it is made of
Earth is rocky.
It is the largest of the rocky planets moving around the Sun by mass and by size.
It is much smaller than the gas giants such as Jupiter.
Chemical make-up
Overall, Earth is made of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8%), calcium (1.5%), and aluminium (1.4%).
The 1.2% left over is made of many different kinds of other chemicals.
Chemicals that are very uncommon (such as gold and platinum) can be very valuable.
The structure of Earth changes from the inside to the outside.
The center of earth (Earth's core) is mostly iron (88.8%), nickel (5.8%), sulfur (4.5%), and less than 1% other things.
The Earth's crust  is largely oxygen (47%).
Oxygen is normally a gas but it can join with other chemicals to make compounds like water and rocks.
99.22% of rocks have oxygen in them.
The most common oxygen-having rocks are silica (made with silicon), alumina (made with aluminium), rust (made with iron), lime (made with calcium), magnesia (made with magnesium), potash (made with potassium), and sodium oxide, and there are others as well.
Earth's shape is a spheroid: not quite a sphere because it is slightly squashed on the top and bottom.
The shape is called an oblate spheroid.
As Earth spins around itself, centrifugal force forces the equator out a little and pulls the poles in a little.
The equator, around the middle of Earth's surface, is about  long.
The highest mountain above sea level—the well-known Mount Everest (which is  above sea level)—is not actually the one that is the farthest away from the center of the Earth.
Instead, the sleeping volcano Mount Chimborazo in Ecuador is; it is only  above sea level but it is almost at the equator.
Because of this, Mount Chimborazo is  from the center of the Earth, while Mount Everest is  closer to it.
Similarly, the lowest point below sea level that we are conscious of is the Challenger Deep in the Mariana Trench in the Pacific Ocean.
It is about  below sea level, but, again, there are probably places at the bottom of the Arctic Ocean that are nearer to the center of the Earth.
Earth’s core
The deepest hole ever dug is only about .
We know something about the inside of the Earth, though, because we can learn things from earthquakes and the times when volcanoes erupt.
We are able to see how quickly the shock waves move through Earth in different places.
The inside of Earth is very different from the outside.
Almost all of Earth's liquid water is in the seas or close to the surface.
The surface also has a lot of oxygen, which comes from plants.
Small and simple kinds of life can live far under the surface, but animals and plants only live on the surface or in the seas.
The rocks on the surface of Earth (Earth's crust) are well known.
They are thicker where there is land, between  thick.
Under the seas they are sometimes only  thick.
There are three groups of rocks that make up most of the Earth's crust.
Some rock is made when the hot liquid rock comes from inside the earth (igneous rocks); another type of rock is made when sediment is laid down, usually under the sea (sedimentary rocks); and a third kind of rock is made when the other two are changed by very high temperature or pressure (metamorphic rocks).
A very few rocks also fall out of the sky (meteorites).
Below the crust is warm and almost-liquid rock that is always moving around (the Earth's mantle).
Then, there is a thin liquid layer of heated rock (the outer core).
This is very hot: .
The middle of the inside of the Earth would be liquid as well but all the weight of the rock above it pushes it back into being solid.
This solid middle part (the inner core) is almost all iron.
This is what makes the Earth magnetic.
Pieces of the crust form plates
The Earth's crust is solid but made of parts which move very slowly.
The thin level of hard rock on the outside of the Earth rests on hot liquid material below it in the deeper mantle.
This liquid material moves because it gets heat from the hot center of the earth.
The slow movement of the plates is what causes earthquakes, volcanoes and large groups of mountains on the Earth.
There are three ways plates can come together.
Two plates can move towards each other ("convergent" plate edges).
This can form islands (such as Japan), volcanoes, and high mountain ranges (such as the Andes and Himalayas).
Two plates can move away from each other ("divergent" plate edges).
This gives the warm liquid rock inside the earth a place to come out.
This makes special mountain ranges below the sea or large low lands like Africa's Great Rift Valley.
Plates are able to move beside each other as well ("transform" plate edges, such as the San Andreas Fault).
This makes their edges crush against each other and makes many shocks as they move.
The outside of the Earth is not even.
There are high places called mountains, and high flat places called plateaus.
There are low places called valleys and canyons.
For the most part, moving air and water from the sky and seas damages rocks in high places and breaks them into small pieces.
The air and water then move these pieces to lower places.
Because of this, the Earth would have been very flat a long time before now.
The fundamental cause of the differences in the Earth's surface is plate tectonics.
The shape of the entire planet itself is not even a ball.
Because of its velocity, Earth has a slight bulge at the Equator.
Other than that, Earth is shaped more like a pear than an actual sphere.
All places on Earth are made of, or are on top of, rocks.
The outside of the Earth is usually not uncovered rock.
Over 70% of the Earth is covered by seas full of salty water.
This salty water makes up about 97% of all Earth's water.
The fresh water people can drink is mostly ice.
Only a very small amount is in rivers and under the Earth for people to drink and use.
The air above the Earth stops the water from going away into outer space.
Also, much of the land on Earth is covered with plants, or with what is left from earlier living things.
Places with very little rain are dry wastes called deserts.
Deserts usually have few living things, but life is able to grow very quickly when these wastes have rainfall.
Places with large amounts of rain may be large woods.
Lately, people have changed the environment of the Earth a great deal.
All around the Earth is a large amount of air (the atmosphere).
The mass of the Earth pulls the gasses in the air down and does not let them go into outer space.
The air is mostly made of nitrogen (about 78%) and oxygen (about 21%) but there are a few other gasses as well.
Most living things need the air (or parts of the air gripped in the water) to breathe and live.
They use the gasses—especially oxygen and carbon dioxide—to make and use sugar and to give themselves power.
The air animals and plants use to live is only the first level of the air around the Earth (the troposphere).
The day to day changes in this level of air are named weather; the changes between places far away from each other and from year to year are named the climate.
Rain and storms are both in this level.
Both come about because this part of the air gets colder as it goes up.
Cold air becomes thicker and falls, and warm air becomes thinner and goes up.
The turning Earth moves the air as well and air moves north and south because the middle of the Earth generally gets more power from the Sun and is warmer than the north and south points.
At the same time, air over water (specially very warm water) gets water in it but, because cold air is not able to take in as much water, it starts to make clouds and rain as it gets colder.
The way water moves around in a circle like this is called the water cycle.
Above this first level, there are four other levels.
The air gets colder as it goes up in the first level; in the second level (the stratosphere), the air gets warmer as it goes up.
This level has a special kind of oxygen called ozone.
The ozone in this air keeps living things safe from damaging rays from the Sun.
The power from these rays is what makes this level warmer and warmer.
The middle level (the mesosphere) gets colder and colder with height; the fourth level (the thermosphere) gets warmer and warmer; and the last level (the exosphere) is almost outer space and has very little air at all.
It reaches about half the way to the Moon.
The three outer levels have a lot of electric power moving through them; this is called the ionosphere and is important for radio and other electric waves in the air.
It is also where the Northern Lights are.
Even though air seems very light, the weight of all of the air above the outside of the Earth (air pressure) is important.
Generally, from sea level to the top of the outer level of the air, a space of air one cm2 across has a mass of about 1.03 kg and a space of air one sq in across has a weight of about 14.7 lb.
The mass of the air also keeps the Earth safe when rocks (meteorites) hit it from outer space.
Without the air, the damage meteorites do would be much greater.
Because of the air, meteorites generally burn up long before they get to the earth.
The air also keeps the Earth warm, specially the half turned away from the Sun.
Some gasses – especially methane and carbon dioxide – work like a blanket to keep things warm.
In the past, the Earth has been much warmer and much colder than it is now.
Since people have grown used to the heat we have now, though, we do not want the Earth to be too much warmer or colder.
Most of the ways people create electric power use burning kinds of carbon—especially coal, oil, and natural gas.
Burning these creates new carbon dioxide and can cause more warming.
A large discussion is going on now about what people should do about the Earth's latest warming, which has gone on for about 150 years.
So far, this warming has been good for people: plants have grown better and the weather has been better than when it was colder before.
Some people who learn about science, though, say that many bad things will possibly come about if the warming goes on.
About eight billion people live on Earth.
They live in about 200 different lands called countries.
Some, for example, Russia, are large with many large cities.
Others, for example, Vatican City, are small.
The five countries with the most people are China, India, the United States, Indonesia, and Brazil.
About 90% of people live in the north half of the world, which has most of the land.
Scientists think that people originally came from Africa.
Now, 70% of all people do not live in Africa but in Europe and Asia.
People change the Earth in many ways.
They have been able to grow plants for food and clothes for about ten thousand years.
When there was enough food, they were able to build towns and cities.
Near these places, men and women were able to change rivers, bring water to farms, and stop floods (rising water) from coming over their land.
People found useful animals and bred them so they were easier to keep.
("WP discussion")
Astronomical objects
Terrestrial planets
Et cetera means "and the rest" in Latin.
It is often used in English to continue a list that is longer than what can be normally written.
People most often write "et cetera" as etc.. Very rarely, it is also written "&c" because the ampersand, or the "&", is the same as "et", having been formed by  'e' and 't' being joined into a single letter.
It is also the symbol for "and".
Some people write it as "ect", but that is wrong since it incorrectly abbreviates "et cetera".
"Jane has a lot of pets.
She has cats, dogs, cows, horses, kangaroos, rabbits, etc."
"Robert ordered a large amount of groceries in order to stock for later.
He ordered carrots, tomatoes, potatoes, eggs, etc."
Latin phrases
An experiment is a test of an idea or a method.
It is often used by scientists and engineers.
An experiment is used to see how well the idea matches the real world.
Experiments have been used for many years to help people understand the world around them.
Experiments are part of scientific method.
Many experiments are controlled experiments or even blind experiments.
Many are done in a laboratory.
But thought experiments are done in mind.
Experiments can tell us if a theory is false, or if something does not work.
They cannot tell us if a theory is true.
When Einstein said that gravity could affect light, it took a few years before astronomers could test it.
General relativity predicts that the path of light is bent in a gravitational field; light passing a massive body is deflected towards that body.
This effect has been confirmed by observing the light of stars or distant quasars being deflected as it passes the Sun.<ref>Shapiro S.S. et al 2004.
Measurement of the solar gravitational deflection of radio waves using geodetic very-long-baseline interferometry data, 1979–1999.
Rev. Lett'.
92 (12): 121101.
Now, a hundred years or so after Einstein published his ideas, there have been many tests, all of which have been consistent with Einstein's predictions.
But, one day, we might find the theory has some limits beyond which it does not work.
What we test are implications of the theory, because the theory itself is too large and complicated to test all at once.
"The universe does not tell us when we are right, only when we are wrong". –
Controlled experiments
A controlled experiment is a kind of comparison.
It often compares the results from experimental samples against control samples.
Control samples are the same as the experimental sample, except for one difference.
This difference is the one thing whose effect is being tested (the independent variable).
A good example would be a drug trial.
The sample or group receiving the drug would be the experimental group (treatment group); and the one receiving the placebo or an older treatment would be the control group.
Difference with observational study
An observational study is used when an experiment would be difficult, unethical, or expensive.
Observational studies are not experiments.
Experiments can control for other variables, and it allows the researchers to change something.
Observational studies often do not have random samples, and they often have many variables.
Famous experiments
Galileo Galilei did some experiments about free fall (1623)
Benjamin Franklin showed that lightning is a form of electricity (1752)
The Michelson–Morley experiment proved a flaw in old physics, and prompted Einstein's work (1887)
Ivan Pavlov did some experiments about the classical conditioning of dogs (1927)
The Avery–MacLeod–McCarty experiment proved DNA was the molecule which caused heredity (1944)
Stanley Milgram showed that people follow orders; this became known as the Milgram experiment (1961)
Shadish, William R; Cook, Thomas D. & Campbell, Donald T. 2002.
Experimental and quasi-experimental designs for generalized causal inference''.
Boston: Houghton Mifflin.
Ethics is the study of good and bad behaviour.
It is one of the main parts of philosophy.
Ethics tries to answer questions like:
What actions are good?
What actions are evil?
How can we tell the difference?
Are good and evil the same?
How should we make hard decisions that might help or hurt other people?
How do our actions affect others?
Ideas about ethics
thinking about morality,
the involvement of science,
the freedom of people to decide for themselves how to act within their own beliefs.
Morality is what someone thinks or feels is good or bad.
things that people think are good or bad.
Their work can be used
An example of this kind of thinking is the categorical imperative.
What is ethics used for?
Understanding ethics can help people decide what to do when they have choices.
Many philosophers think that doing anything or making any choice is a part of ethics.
Ethics is part of other fields of study in many ways.
Here are some ways:
Ethics is part of the study of religion.
In religion, people often learn what is good or bad from what they believe about God (or gods).
Some important ideas about what is good or bad have come from religion.
See Ten Commandments.
Some theories of economics say ethics has to do with money.
Money is a big part of most people's lives.
Thinking about morality can be important in economics.
For example, there is a saying about ethics taken from the Bible that 'the love of money is the root of all kinds of evil' (1 Timothy).The philosophy of Marxism also says that a few people using money in the wrong way can hurt many other people.
Government policy can be affected by what politicians think is ethical.
Politicians try to create laws that help everyone do what is right.
Political debates happen when the people who make public policy do not agree about what is right.
In work, thinking about ethics can help with hard questions.
Work can be like both economics and politics.
Workers have to make money and follow laws.
But the best way to do both is not always easy to know.
The study of this is called business ethics
People like doctors and nurses have to make hard choices about how to care for people.
Sometimes the person being cared for, their family or the doctor do not agree what is best for them.
Also, choices have to be made if there are enough resources to help all.
The study of this is called medical ethics.
Similar studies for specific professions include bioethics and legal ethics.
Discussing ethics can also be a way to stop people fighting or starting a war.
By talking about ethics, people hope to get what they want without being violent.
This works when all people agree that peace is very important.
But not everyone agrees about what is right or wrong.
So, sometimes anger can make it hard to talk without fighting.
The Republic, a book by Plato that says that people who have power should use ethics to make choices.
The Prince, a book by Niccolò Machiavelli that says that people who have power should not use ethics to make choices.
Aristotle, Nicomachean Ethics
The London Philosophy Study Guide  offers many suggestions on what to read, depending on the student's familiarity with the subject:  Ethics
Encyclopedia of Ethics.
Lawrence C. Becker and Charlotte B. Becker, editors.
Second edition in three volumes.
New York: Routledge, 2002.
A scholarly encyclopedia with over 500 signed, peer-reviewed articles, mostly on topics and figures of, or of special interest in, Western philosophy.
Blackburn, S. (2001).
Being good: A short introduction to ethics.
De Finance, Joseph, An Ethical Inquiry, Rome, Editrice Pontificia Università Gregoriana, 1991.
Derrida, J. 1995, The Gift of Death, translated by David Wills, University of Chicago Press, Chicago.
Fagothey, Austin, Right and Reason, Tan Books & Publishers, Rockford, Illinois, 2000.
Solomon, R.C. Morality and the Good Life: An Introduction to Ethics Through Classical Sources, New York: McGraw-Hill Book Company, 1984.
Vendemiati, Aldo, In the First Person, An Outline of General Ethics, Rome, Urbaniana University Press, 2004.
John Newton, Ph.D. Complete Conduct Principles for the 21st Century, 2000. .
Guy Cools & Pascal Gielen, The Ethics of Art.
Valiz: Amsterdam, 2014.
Lafollette, Hugh [ed.]:
Ethics in Practice: An Anthology.
Wiley Blackwell, 4th edition, Oxford 2014.
Brute Ethics: animal ethics encyclopedia
E Prime (it means English Prime) is a way of speaking English without using the verb "to be" in any way ("be, is, am, are, was, were, been, and being").
Instead, an E Prime speaker or writer uses different verbs like "to become," "to remain," and "to equal" or they might choose to rearrange the sentence to show that the "thing" does not actually "act".
For example, in E Prime, a writer would change the statement "Mistakes were made" to "Joe made mistakes."
This change in wording reveals an actor (Joe) where the previous form concealed the actor.
Users of E Prime would consider the changed sentence more accurate.
What E Prime is
D. David Bourland, Jr. first suggested E Prime in 1965.
Bourland had studied the discipline (way of thinking) of General Semantics.
The main idea of General Semantics is that people can only know what they observe and experience when they see, hear, touch, taste, smell, think, and feel, and furthermore, that what they observe and experience can affect how they observe and experience in the future.
Because each person has different experiences throughout their lives, they interpret their experiences differently.
Students of General Semantics and users of E Prime contend that to say "This cat is soft" leaves out many other attributes, and implies that the outside "object" of the cat is the "same as" the inside experience of "softness".
Instead, E Prime users say "This cat feels soft TO ME" to remind themselves of the following:
That their experience of "softness" involves both the outside "object" called "cat" and the eyes, hands, brain and nervous system of the observer.
That someone else might experience different aspects of the cat.
That they themselves might experience something different at a different time or in different circumstances. (
The cat might scratch them, or look or feel wet or matted with dirt.)
What E Prime is not
Although languages like Russian, Arabic, Turkish, and Cantonese do not always use a separate verb for "to be," they do have the idea of "being."
For example, an English speaker might say "This apple is red."
An Arabic speaker might say "This apple red."
Most languages can be used to express the idea of a red apple.
An E Prime user chooses to say "This apple looks red to me" to remind themselves that "seeing red" involves both the apple and the eye and brain of the person looking at the apple.
Many teachers of English encourage students to use verbs other than "to be."
To them, using more active verbs makes writing clearer and more interesting.
These teachers want to improve their students' writing and may not agree with the ideas of General Semantics or E Prime.
Different functions of 'to be'
It talks about Identity: The cat is my only pet, The cat is Garfield
It talks about belonging to a class, or a group: The cat is an animal
It can talk about properties: The cat is furry
It can be an auxiliary verb: The cat is sleeping, The cat is bitten by the dog
It can talk about existence: There is a cat
It can talk about location: The cat is here
Einstein on the Beach is an opera written by the minimalist composer Philip Glass and theater director and designer Robert Wilson.
It was first acted for an audience in Avignon, France in 1976.
It is a single act opera, about five hours long with no intermission.
Because of the length and the minimalist (repetitive) nature of the music, audience members are free to enter and leave the opera as they wish.
Glass's music tends to cycle round, but does not exactly repeat itself.
Admittedly, he has described himself as a composer of "music with repetitive structures".
Though his earlier music fits what is normally called "minimalist", he has since evolved stylistically.
1970s operas
Were you looking for English Wikipedia, the full English Wikipedia version of Simple?
From or about the country England
The Amish word for somebody who is not in their group
Avoirdupois, a system of measurement sometimes called "English".
English opening, a chess opening
English, Indiana, the county seat of Crawford County
An ethnic group is a group of people who are considered to be the same in some or multiple ways.
They may all have the same ancestors, speak the same language, or have the same culture, which could sometimes include religion.
They often live in the same or surrounding area.
Sometimes almost all of the people in one country are of the same ethnic group, but not always.
Often one country may have several different ethnic groups, or the people of one ethnic group may live in several different countries.
An example of an ethnic group is the Slavic peoples.
Supraethnicity or supra-ethnicity: a grouping of several interrelated ethnicities that have similar but unique cultures.
A female sheep
Ewe language
Ebola virus or Ebola virus disease (EVD), often shortened to Ebola, is a very dangerous virus.
It belongs to the family Filoviridae.
Four different types of Ebola virus can cause a severe disease which is often fatal.
Ebola infection causes hemorrhagic fever which starts suddenly. "
Hemorrhagic" means that the victim will bleed a lot, inside and outside of their body.
The virus attacks almost every organ and tissue of the human body, causing multiple organs to fail at once.
Out of every 100 people who get Ebola, on average 25 to 90 die.
The virus was first found in Sudan.
It is mostly found in Africa, with very few cases in Europe and the United States.
The Ebola virus that makes people sick lives in the blood and other liquids and wet things in some kinds of non-human animals without killing them.
Scientists think the animals it lives in are mainly some kinds of monkeys or fruit bats.
When people touch animals that have the virus, or wet things that came out of those animals, they can get sick.
Ebola cannot be caught through the air, or by being near sick people.
The virus can only go from liquids into people's bodies.
This means Ebola can be caught by touching a sick person's blood, saliva, mucus, semen, diarrhea, vomit, or other fluids that come out of a sick person's body.
If a person does not die from the disease, he can still give other people the infection by having sex for nearly another two months after they stop being sick.
This is because the virus can still be in the man's semen after a long time.
Once the virus enters the human body via mucosal surfaces, abrasions or injuries in the skin or by direct parental transmission, it fuses with the cells lining the respiratory tract, eyes, or body cavities.
It invades the macrophages and dendritic immune cells and releases its genetic content.
The cell explosion triggers the secretion of proinflammatory cytokines initiating a ‘cytokine storm’.
The genetic material takes over the cell machinery to replicate itself; new copies of the virus are formed and released into the system.
The virus then, goes on to attack spleen, kidneys and even the brain.
The blood vessels leak blood and fluid into the surrounding tissues.
This atypical clotting and bleeding at the same time manifests externally in the form of rashes.
The virus causes the shutdown of other vital organs such as liver and lungs too.
In fact, it is able to invade almost all human cells through different attachment mechanisms for each cell type (except for lymphocytes).
The very cells that are meant to fight infection are used as carriers to spread infection to other body parts
It has been found that the ebola-infected cells do not undergo normal apoptosis, but exhibit vacuolization and signs of necrosis.
When people get Ebola the first symptoms look like some other diseases.
People get a fever and feel very tired.
Their head, stomach, joints, and throat might hurt.
Sometimes, people think they have other diseases like malaria or typhoid fever.
Later, people get much sicker.
They bleed both inside and outside their bodies.
They have blood in their diarrhea and vomit.
They bleed from their noses, mouths, and genitals/sex organs.
They get shock: low blood pressure, fast pulse (heart rate), and low blood circulation to the body.
Their organs might stop working.
Ebola also causes stiffness throughout the body which makes it hard for sick people to move.
There is no cure for Ebola, but if people get care quickly from doctors and nurses at a hospital, more of them live.
People with Ebola need a lot of fluids to replace fluids lost from diarrhea, vomiting, and bleeding.
The most important care is giving them water with a very small amount of salt and sugar in it.
This is called oral rehydration.
It helps to replace their fluids and blood.
It is also important to give medicines in case they get bad blood pressure and blood circulation.
World Community Grid is a computing project that is seeking possible drug treatments.
People donate the spare time on their computers to the project.
Infectious diseases
Diseases caused by viruses
Ecology is the branch of biology that  studies the biota (living things), the environment, and their interactions.
It comes from the Greek oikos = house; logos = study.
Ecology is the study of ecosystems.
Ecosystems describe the web or network of relations among organisms at different scales of organization.
Since ecology refers to any form of biodiversity, ecologists research everything from tiny bacteria in nutrient recycling to the effects of tropical rain forests on the Earth's atmosphere.
Scientists who study these interactions are called ecologists.
There are many practical applications of ecology in conservation biology, wetland management, natural resource management (agriculture, forestry, fisheries), city planning (urban ecology), community health, economics, and applied science.
It provides a framework for understanding and researching human social interaction.
Population ecology measures the size of a population: all the living things from one species that live in an place.
A population gets bigger because of birth and movement into a place, and it gets smaller because of death and movement out of a place.
Growth rate is the change in population size divided by the current population size.
When a population is small, growth rate does not change, so the population shows exponential growth.
Rate of exponential growth depends on how a living thing reproduces.
If it has only a few offspring (children) which grow slowly, like a human, the rate will be low.
If it has a lot of offspring which grow quickly, like a fruit fly, the rate will be high.
Any environment only has enough resources, such as food, water, or space, for a certain size of population.
This size is called the carrying capacity.
When population size is near the carrying capacity, growth rate will become less.
The graph of population growth will be an S-shape, called logistic growth.
Community and ecosystem ecology
A community is all populations of different species that live in the same place.
An ecosystem is a community and its environment.
Ecosystem ecology studies how energy and nutrients move through an ecosystem.
All living things need energy to survive, move, grow, and reproduce.
A trophic level is the number of times energy moves from one living thing to another, before reaching a particular living thing.
The first trophic level, called producers or autotrophs, gets energy from the environment.
They use the energy to make organic compounds.
Most producers, such as plants, take in energy from sunlight, but some take it from inorganic compounds.
Other trophic levels, called consumers or heterotrophs, get their energy by eating other living things.
All animals are consumers, and there are three kinds: herbivores, carnivores, and omnivores.
Herbivores eat only plants, carnivores eat only other animals, and omnivores eat both.
Decomposers are living things which break down dead things.
A food web shows the movement of energy in an ecosystem.
Humans and ecology
Ecology in politics
Ecology starts many powerful philosophical and political movements - including the conservation movement, wellness movement, environmental movement, and ecology movement we know today.
When these are combined with peace movements and the Six Principles, they are called green movements.
In general, these put ecosystem health first on a list of human moral and political priorities, as the way to achieve better human health and social harmony, and better economics.
People with these beliefs are called political ecologists.
Some have organized into the Green Parties, but there are actually political ecologists in most political parties.
They very often use arguments from ecology to advance policy, especially forest policy and energy policy.
Ecology includes economics
Lynn Margulis says that economics studies how humans make a living, while ecology studies how every other animal makes a living.
Mike Nickerson says that "economy is three-fifths of ecology", since ecosystems create resources and dispose of waste, which the economy assumes is done "for free".
Ecological economics and human development theory try to separate the economic questions from others, but it is difficult.
Many people think economics is just part of ecology now, and that economics that ignores it is wrong. "
Natural capital" is an example of one theory combining both.
Ecology and anthropology
Sometimes ecology is compared to anthropology.
Anthropology includes how our bodies and minds are affected by our environment, while ecology includes how our environment is affected by our bodies and minds.
There is even a type of anthropology called ecological anthropology, which studies how people interact with the environment.
Antoine de Saint-Exupery stated: "The earth teaches us more about ourselves than all the books.
Because it resists us.
Man discovers himself when he measures himself against the obstacle".
Prey-predator equations
Economics is the social science which studies economic activity: how people make choices to get what they want.
It has been defined as "the study of scarcity and choice" and is basically about the choices people make.
It also studies what affects the production, distribution and consumption of goods and services in an economy.
Investment and income relate to economics.
The word comes from Ancient Greek, and relates to οἶκος oíkos "house" and νόμος nomos "custom" or "law".
The models used in economics today were mostly started in the 19th century.
People took ideas from political economy and added to them because they wanted to use an empirical approach similar to the one used in the natural sciences.
Subjects and objects in economics
The subjects (actors) in economic study are households, business companies, the government (the state), and foreign countries.
Households offer their "factors of production" to companies.
This includes work, land, capital (things like machines and buildings) and information.
In exchange for their factors of production, households get income which they use to consume (buy) goods from other subjects.
The state or public sector includes institutions and organisations.
The state takes some of the earnings from the business companies and households, and uses it to pay for "public goods" like streets or education, to be available for everyone.
The last subject is foreign countries.
This includes all households, business companies and state institutions, which are not based in one's own country.
They demand and supply goods from abroad.
The objects (things acted upon) in economic study are consumer goods, capital goods, and factors of production.
Consumer goods are classified as "usage goods" (for example, gasoline or toilet paper), as "purpose goods" (for example, a house or bicycle), and as "services" (for example, the work of a doctor or cleaning lady).
Capital goods are goods which are necessary for producing other goods.
Examples of these are buildings, equipment, and machines.
Factors of production are work, ground, capital, information, and environment.
General economic rules
All people have to decide between their options.
The cost of goods is what a person gives up for the goods.
When a person gives up something (like money) to get a good, they also give up other things that they could have gotten instead.
This means that the true cost of something is what you give up to get it.
This includes money, and the economic benefits ("utility") that you didn't get because you can no longer buy something else.
This is called opportunity cost.
People choose between options based on the rewards ("incentives") or bad things ("disincentives") they expect from each option.
Adding to the rewards for an option will often make more people choose it.
Trade can make everyone better off.
Markets are usually good for the organisation of economic life.
In the free market, goods will be shared by people and companies making small decisions.
The “invisible hand” of the market (Adam Smith) states that if everyone tries to get what they want, everyone will be as well-off as they could possibly be.
Sometimes prices do not fully show the cost or benefit to society.
For example, air pollution is bad for society, and education is good for society.
The government can put a tax (or do something to reduce sales) on items that are bad for society.
It can also support (like giving money for) items that are good for society.
The living standard of a country depends on the skills to produce services and goods.
Productivity is the amount of the produced goods divided by total working hours.
When there is an increase in the total money supply, or when the cost to produce things rises, prices go up.
This is called inflation.
18th century analysis of wealth
Austrian economics
The ideas that economists have depend a lot on the times they live in.
For example, Karl Marx lived in a time when workers' conditions were very poor, and John Maynard Keynes lived through the Great Depression of the 1930s.
Today's economists can look back and understand why they made their judgments, and try to make better ones.
Branches of economics
Macroeconomics is about the economy in general.
For example, macroeconomists study things that make a country's wealth go up and things that make millions of people lose their jobs.
Microeconomics is about smaller and more specific things such as how families and households spend their money and how businesses operate.
Business economics
Economic policy Analysis
Energy economics
Industrial economics
Mathematical economics or econometrics
Resource economics
Urban economics
Public economics
descriptive, theoretical and policy economics
monetary economics
Famous economists
Adam Smith (His works include The Wealth of Nations and The Theory of Moral Sentiments.
First introduce the concept of "Invisible Hand").
Thomas Malthus (Author of An Essay on the Principle of Population.
Establish the theory of population ).
David Ricardo (First introduce the theory of Comparative advantage).
Karl Marx (His works include Das Kapital and The Communist Manifesto; a famous critique of Capitalism).
John Maynard Keynes (Founder of the school of Keynesian economics).
Milton Friedman (Proponent of monetarism.
His works include Capitalism and Freedom ).
Famous economists of the 19th and 20th century include Friedrich August von Hayek, Wassily Leontief,  Carl Menger, and Léon Walras.
Economics Citizendium
A chemical element is a substance that is made up of only one type of atom.
Atoms are made up of protons, neutrons, and electrons.
The number of protons in an atom is called the atomic number.
For example, all atoms with 6 protons are atoms of the chemical element carbon, and all atoms with 92 protons are atoms of the element uranium.
The number of neutrons in the nucleus does not have to be the same in every atom of an element.
Atoms of the same element with different numbers of neutrons are called isotopes.
Saying that a substance "contains only one type of atom" really means that it contains only atoms that all have the same number of protons.
The number of protons in the nucleus causes its electric charge.
This fixes the number of electrons in its normal (un-ionized) state.
The electrons in their atomic orbitals determine the element's various chemical properties.
Elements are the basic building blocks for all types of substances.
If a substance contains more than one type of atom, it is a compound or a mixture.
The smallest particle of a compound is a molecule.
118 different chemical elements are known to modern chemistry.
92 of these elements can be found in nature, and the others can only be made in laboratories.
The human body is made up of 26 elements.
The last natural element discovered was uranium, in 1789.
The first man-made element was technetium, in 1937.
Chemical elements are commonly arranged in the periodic table.
Where the elements are in the table tells us about their properties relative to the other elements.
Chemical symbols
Chemical elements are given a unique chemical symbol.
Chemical symbols are used all over the world.
This means that, no matter which language is spoken, there is no confusion about what the symbol means.
Chemical symbols of elements almost always come from their English or Latin names.
For example, carbon has the chemical symbol 'C', and sodium has chemical symbol 'Na', after the Latin natrium.
Tungsten is called 'W' after its German name, wolfram. '
Au' is the symbol for gold and it comes from the Latin word for gold, aurum.
Another symbol which comes from Latin is 'Ag'.
This is the element silver and it comes from the Latin argentum.
Lead's symbol, 'Pb', comes from the Latin plumbum and the English word plumber derives from this as pipes used to be made out of lead.
Some more recently discovered elements were named after famous people, like einsteinium, which was named after Albert Einstein.
Elements can join (react) to form pure compounds (such as water, salts, oxides, and organic compounds).
In many cases, these compounds have a fixed composition and their own structure and properties.
The properties of the compound may be very different from the elements it is made from.
Sodium is a metal that burns when put into water and chlorine is a poisonous gas.
When they react together they make sodium chloride (salt) which is generally harmless in small quantities and edible.
Some elements mix together in any proportion to form new structures.
Such new structures are not compounds.
They are called mixtures or, when the elements are metals, alloys.
Most elements in nature consist of atoms with different numbers of neutrons.
An isotope is a form of an element with a certain number of neutrons.
For example, carbon has two stable, naturally occurring isotopes: carbon-12 (6 neutrons) and carbon-13 (7 neutrons).
Carbon-14 (8 neutrons) is a naturally occurring radioactive isotope of carbon.
At least two isotopes of each element are known (except for Oganesson, of which only a few atoms have been made).
Elements can be classified based on physical states.
At room temperature and pressure, most elements are solids, only 11 are gases and 2 are liquids.
Elements can also be classified into metals and non-metals.
There are many more metals than non-metals.
However, a few elements have properties in between those of metals and non-metals.
These elements are called semimetals (or metalloids).
Egypt is a country in northeast Africa, parts of the country hang on to the Middle East.
Its capital city is Cairo.
Egypt is famous for its ancient monuments, such as the Pyramids and the Sphinx.
Ancient Egypt has one of the longest histories of any country in the world as it used to be ruled by pharaohs.
As a province of the Roman Empire, it became Christian and some Coptic Church people are thereafter more than a thousand years of Muslim rule.
The Fatimid Caliphate ruled Egypt in the tenth through twelfth centuries.
Mamlukes ruled it until 1798 when Napoleon defeated them.
Muhammad Ali Pasha soon took over and started a dynasty of Khedives under the Ottoman Empire.
The Empire fell apart after World War I. Egypt became an independent country in 1922 and the khedive became a king.
Egypt is a member of the United Nations and the Arab League.
It became a republic after the Army's revolution of 1952.
Egypt is a large country, but a large portion of it is desert.
Most people (95% of Egypt's total people) live in areas around the coast of the Mediterranean Sea and along the Nile River.
This includes the cities of Cairo, Alexandria, Aswan, and Port Said.
Not many people live in the desert.
Today, Egypt has about 90 million people.
Egypt is a country that has had many different rulers and many political systems.
After World War II, Egypt was still ruled by a king, Farouk of Egypt (11 February 1920 – 18 March 1965).
He was the last ruler of the Muhammad Ali dynasty.
Farouk was overthrown on 23 July 1952 by a military coup.
The coup was led by Muhammad Naguib, and Gamal Abdel Nasser.
From then on, Egypt had military rulers or rulers who had the backing of the army and many citizens.
Nasser became President, from 1956 to 1970.
Later rulers were Anwar Sadat, and Hosni Mubarak.
Revolution of 2011
In January 2011, thousands of protesters gathered in Cairo.
They wanted Hosni Mubarak to leave office.
He had been the President for almost 30 years.
On February 11, 2011, Vice President Omar Suleiman made an announcement.
He said that Mubarak agreed to leave office.
In 2012, Egypt had a democratic election for the post of President.
The winner was the Muslim Brotherhood candidate, Mohamed Morsi.
The events which followed are still controversial, but one aspect stands out.
Morsi issued a declaration that in effect gave him unlimited powers.
He had the power to legislate (make laws) without legal overview by the courts.
This caused widespread protests.
On 3 July 2013, he was unseated by a military coup council (a coup d'état).
After an election in June 2014, Abdel Fattah el-Sisi became President of Egypt.
Islamist movements, such as the Muslim Brotherhood, rejected the change of regime as a military coup, and not democratic.
Today, the people of Egypt are mostly Sunni Muslims.
There are many Christians in Egypt today.
Many of these belong to the Coptic Orthodox Church of Alexandria.
The official language in Egypt is Arabic.
The majority speak Egyptian Arabic but many speak other dialects.
Some Egyptians still speak Coptic and English.
They also speak French and German in Egypt.
These are taught in Egypt as additional languages.
Many famous people are from Egypt.
Some of these include Omar Sharif, who was an international actor, Boutros Boutros-Ghali, who was the first person from Africa to lead the United Nations, and four Nobel Prize winners: Anwar Sadat, who won the Nobel Peace Prize in 1978, Naguib Mahfouz, who won the Nobel Prize in Literature in 1988, Ahmed Zewail, who won the Nobel Prize in Chemistry in 1999, and Mohamed ElBaradei, who won the Nobel Peace Prize in 2005.
Mohamed Salah is a famous footballer who plays for Liverpool in England.
A famous Egyptian singer is called Amr Diab.
Governorates
Egypt is divided into 27 governorates.
The governorates are divided into regions.
The regions have towns and villages.
Each governorate has a capital.
Sometimes capital has the same name as the governorate.
Egypt is a country with an immense cultural mix.
Life in the countryside differs from life in large cities.
There are differences between the families which are Muslim, and the smaller number which are Coptic Christians.
There are noticeable differences in the standards of education.
Tourism is one of the most important national incomes in Egypt.
In 2008, about 12 million tourists visited Egypt providing nearly $12 billion of national income to Egypt.
Tourism affects the economy of the country as a whole.
Giza Necropolis is one of Egypt's iconic sites.
It is a popular destination for tourists to visit.
It includes the Great Pyramid of Giza, one of the Seven Wonders of the World.
There are methods of transport in Egypt.
The Suez Canal carries ships of many countries.
Cairo Metro is one of the most important projects in Egypt.
It consists of 3 lines.
Metro is the most preferable transport in Egypt due to persistent major traffic jams in the streets of Cairo.
Metro line 4 is being developed to reach the New Cairo District.
Egypt established EgyptAir in 1932.
The airline is based in Cairo International Airport and is owned by the government.
1922 establishments in Africa
Everything2 or E2 is a website.
It lets people make pages about many different things, and some people use it as a diary.
E2 users create pages called nodes and add stuff in writeups.
Only logged-in users can create writeups.
Only the person who created the writeup or someone who the website owners (called "gods") choose can edit the writeup.