the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
As the string moves, it traces width, and thus becomes 2D, a worldsheet.
As a string vibrates and moves within the 6D Calabi-Yau space, the string becomes a quantum particle.
With this approach, the hypothetical graviton—predicted to explain general relativity—emerges easily.
String theory began as bosonic string theory, whose 26 dimensions act as many fewer.
Yet this modeled only bosons, which are energy particles, while omitting fermions, which are matter particles.
So bosonic string theory could not explain matter.
Yet by adding supersymmetry to bosonic string theory, fermions were achieved, and string theory became superstring theory, explaining matter, too.
(In versions of quantum field theory that include supersymmetry (SUSY), each boson has a corresponding fermion, and vice versa.
That is, each energy particle has a corresponding matter particle, and each matter particle has a corresponding energy particle, yet the unobservable partner is more massive and thus super.
These superpartners might seem an extravagant prediction, yet many theorists and experimentalists favor supersymmetric versions of the Standard Model, whose equations must otherwise be tweaked extravagantly and sometimes arbitrarily to maintain predictive success or mathematical consistency, but with the superpartners align.)
Untestable—unscientific?
String theory's claim that all molecules are strings of energy has drawn harsh criticism.
There are many versions of string theory, none quite successfully predicting the observational data explained by the Standard Model.
M theory is now known to have countless solutions, often predicting things strange and unknown to exist.
Some allege that string theorists select only the desired predictions.
The allegation that string theory makes no testable predictions is false, as it makes many.
No theory—a predictive and perhaps explanatory model of some domain of natural phenomena—is verifiable.
All conventional physical theories until the Standard Model have made claims about unobservable aspects of the natural world.
Even the Standard Model has various interpretations as to the natural world.
When the Standard Model is operated, it is often made a version with supersymmetry, doubling the number of particle species so far identified by particle physicists.
None can literally measure space, yet Newton postulated absolute space and time, and Newton's theory made explicit predictions, highly testable and predictively successful for 200 years, but the theory was still falsified as explanatory of nature.
Physicists accept that there exists no such attractive force directly attracting matter to matter, let alone that the force traverses the universe instantly.
Nevertheless, Newton's theory is still paradigmatic of science.
Hidden dimensions?
The idea of hidden dimensionality of space can seem occult.
Some theorists of loop quantum gravity—a contender for quantum gravity—regard string theory as fundamentally misguided by presuming that space even has a shape until particles shape it.
That is, they do not doubt that space takes various shapes, simply regard the particles as determining space's shape, not the other way around.
The spacetime vortex predicted by general relativity is apparently confirmed.
If interpreted as naturally true, the Standard Model, representing a quantum particle as a 0D point, already indicates that spacetime is a sea of roiling shapes, quantum foam.
String theorists tend to believe nature more elegant, a belief that loop theorist Lee Smolin dismisses as romantic while using biology's Modern Synthesis as a rhetorical device.
Experiments to detect added spatial dimensions have so far failed, yet there is still the possibility that signs of them can emerge.
So many solutions?
M theory has many trillions of solutions.
Leonard Susskind, a leader of string theory, interprets string theory's plasticity of solutions as paradoxical support resolving the mystery of why this universe exists, as M theory shows it but a variant of a general pattern that always approximately results.
General relativity has brought many discoveries that in 1915 were all but unimaginable except in fiction.
A solution of Einstein's equations that sought to explain quantum particles' dynamics, the Einstein-Rosen Bridge predicts a shortcut connecting two distant points in spacetime.
Commonly called a wormhole, the Einstein-Rosen Bridge is doubted but not disproved, showing either that not all consequences of a theory must be accurate or that reality is quite bizarre in ways unobservable.
Many worlds
Even the Standard Model of particle physics suggests bizarre possibilities that populist accounts of science either omit or mention as unexplained curiosities.
The theory conventionally receives the Copenhagen interpretation, whereby the field is only possibilities, none real until an observer or instrument interacts with the field, whose wavefunction then collapses and leaves only its particle function, only the particles being real.
Yet wavefunction collapse was merely assumed—neither experimentally confirmed nor even mathematically modeled—and no variance from either the wavefunction in the quantum realm or the particle function in the classical realm has been found.
In 1957 Hugh Everett described his "Relative state" interpretation.
Everett maintained that the wavefunction does not collapse, and since all matter and interactions are presumed to be built up from quantum waveparticles, all possible variations of the quantum field—indicated by the mathematical equations—are real and simultaneously occurring but different courses of history.
By this interpretation, whatever interacts with the field joins the field's state that is relative to the observer's state—itself a waveform in its own quantum field—while the two simply interact in a universal waveform never collapsing.
By now, many physicists' interpretation of the apparent transition from the quantum to the classical realms is not wavefunction collapse, but quantum decoherence.
In decoherence, an interaction with the field takes the observer into only one determinant constellation of the quantum field, and so all observations align with that new, combined quantum state.
Everett's thesis has inspired Many worlds interpretation, whereby within our universe are predicted to be virtually or potentially infinite parallel worlds that are real, yet each a minuscule distance from the other worlds.
As each world's waveform is universal—not collapsing—and its mathematical relations are invariant, parallel worlds simply fill the gaps and do not touch.
Many universes
Einstein doubted that black holes, as predicted by the Schwarzschild solution, are real.
Some now conjecture that black holes do not exist as such but are dark energy, or that our universe is both—a black hole and dark energy.
The Schwarzschild solution of Einstein's equations can be maximally extended to predict a black hole having a flip side—another universe emerging from a white hole.
Perhaps our universe's big bang was half of a big bounce, something's collapse down to a black hole, and our universe popping out its other side as a white hole.
Particles are strings?
Physicists widely doubt that quantum particles are truly 0D points as represented in Standard Model, which offers formalism—mathematical devices whose strokes predict phenomena of interest upon input of data—not interpretation of the mechanisms determining those phenomena.
Yet string theorists do tend to optimistically conjecture that the strings are both real and explanatory, not merely predictive devices.
It is far beyond the capacity of today's particle accelerators to propel any probing particles at energy levels high enough to overcome a quantum particle's own energy and determine whether it is a string.
Yet this limitation also exists on testing other theories of quantum gravity.
Developments suggest other strategies to "observe" the structure of quantum particles.
Paradoxically, even if testing confirmed that particles are strings of energy, that still would not conclusively prove even that particles are strings, since there could be other explanations, perhaps an unexpected warpage of space although the particle was a 0D point of true solidity.
Even when predictions succeed, there are many possible explanations—the problem of underdetermination—and philosophers of science as well as some scientists do not accept even flawless predictive success as verification of the successful theory's explanations if these are posed as offering scientific realism, true description of the natural world.
Matter is energy?
Talk of particle physicists testing theoretical physicists' predicted particles by colliding particles in accelerators suggests that quantum particles are tiny Newtonian particles that experimentalists crack open to reveal their structure.
Instead, when two particles, each of a certain mass—measured in terms of energy as electronvolts—are collided, they can combine into a particle of that combined mass/energy, and the generated particle is "observed" for correspondence with the prediction.
It is not controversial among physicists that all particles are energy.
Loop theorists, sometimes in rivalry with string theory, claim that spacetime itself converts into the particles.
Matter's being a special variant of energy was a consequence of Einstein's special theory of relativity, and thereupon Einstein formalized the mass-energy equivalence, E=mc2.
When sufficiently energetic photons collide, they can combine and generate matter—matter creation.
All particles have antiparticles, and atoms of matter have antiatoms of antimatter, whose union annihilates the particles and matter while leaving energy.
String theory is usually solved through conformal field theory, a quantum field theory on 2D space.
It is confirmed that molecules can collapse to 2D.  And the electron, long presumed an elementary particle, apparently splits into three entities separately carrying the electron's three degrees of freedom when the molecules that contain the electrons are channeled through a 1D pathway.
A scientist is a person who studies or has mastered the field in science.
A scientist tries to understand how our world, or other things, work.
Scientists make observations, ask questions and do extensive research work in finding the answers to many questions others may not know about.
Scientists have researched many things.
Scientists may work in laboratories for governments, companies, schools and research institutions.
Some scientists teach at universities and other places and train people to become scientists.
Scientists often do experiments to find out more about reality, and sometimes may repeat experiments or use control groups.
Scientists who are doing applied science try to use scientific knowledge to improve the world.
Types of scientists
Scientists that study physics are physicists.
Scientists that study chemistry are chemists.
Scientists that study biology are biologists
Scientists that study rocks are geologists
Scientists that study plants are botanists
Scientists that study minds are psychologists
Scientists that study farming are agricultural scientists
Science occupations
A soapbox is a temporary platform used to give a speech.
During the 19th century, soap was transported in wooden boxes.
When a person had new or unusual ideas, and wanted to talk to a crowd about them, sometimes he or she would stand on an empty soapbox so that everyone could see and hear the talk well.
The word supernatural (from ) is used for things that some people believe are real, but that are not part of nature or inexplicable by the scientific laws of nature.
Because we cannot prove whether these things are real, people often disagree about these things.
Some say that we should talk about things without talking about the supernatural, because we cannot prove that supernatural things are real.
Other people say that although we cannot prove supernatural things in a scientific way, they are real.
Some examples of supernatural things or examples are:
demonic possession
souls, spirits or ghosts
yōkai
devils, asuras or demon
legendary creatures
God or gods
parapsychology
Near death experiences
A spirit is considered to be the part of a being that is not the body.
Other words with the same meanings are soul and ghost.
When a body is alive, it has a spirit in it.
Death is when the spirit separates from the body.
Christians believe that spirits exist in Heaven or Hell. (
See 1 Timothy 3:16, 4:1)
Spiritualists believe that spirits can talk with people, or change things in the world.
Many religions forbid communicating with such spirits in any way, (see Leviticus 19:31) but a few include this as part of their practice.
Another use of spirit means the main purpose or meaning of a sentence or document.
For example, the "spirit of a law" is the true meaning of the law which the creator wanted.
This phrase is often used when the words and sentences of a law could mean more than one thing, but a judge must decide what meaning is correct.
A seed is the part of a seed plant which can grow into a new plant.
It is a reproductive structure which disperses, and can survive for some time.
A typical seed includes three basic parts: (1) an embryo, (2) a supply of nutrients for the embryo, and (3) a seed coat.
There are many different kinds of seeds.
Some plants make a lot of seeds, some make only a few.
Seeds are often hard and very small, but some are larger.
The coconut is as big as a child's head, but it contains more than just a seed.
At the start, seeds are dormant (resting inside their coat) for a while.
When the seed is ready to develop, it needs water, air and warmth but not sunlight to become a seedling.
Seeds carry the food that helps the new plant begin to grow.
This food store is in the endosperm, and/or in the cotyledons.
Many kinds of seeds are good food for animals and people.
The many kinds of grain that people grow, such as rice, wheat, and maize, are all seeds.
Seeds are often inside fruits.
Development from the seed
A seed, though not active, is a tiny living thing.
It contains the embryo of the future plant, which is not changing or developing: it is dormant.
The common idea is that the seed "sleeps" until it gets what it needs to wake up.
Different seeds have different habits, no doubt adapted to their habitat.
There are different kinds of resting stages in seeds:
Seed dormancy: means the seed does not develop for a while even when conditions are suitable.p98 Delayed germination (development) allows time for dispersal.
Changes take place inside the seed which sooner or later make it germinate.
The details vary hugely between species.
Seed hibernation: fails to germinate because conditions are not right.
Growth is triggered by particular events in the environment.
Details of the triggers are known for some, but not all, seeds.
Rain, fire, ground temperature, are examples.
Many seeds only germinate after they have been eaten and passed through the digestive system of an animal.
This also is a dispersal method.
When a seed germinates ("wakes up"), it begins to grow into a little plant called a seedling.
It uses the soft fleshy material inside the seed for nutrients (food) until it is ready to make food on its own using sunlight, water and air.
Most seeds germinate underground where there is no sunlight.
The plant does not need the nutrients in soil for a few days or weeks, because the seed has all the things it needs to grow.
Later, though, it will begin to need sunlight.
If there is sunlight, the plant will use it to grow healthy.
If there is no light, the plant will still grow for a while, but its plastids will not mature: the chlorophyll does not turn green.
If the plant does not get enough light, it will eventually die.
It needs light to make food for itself when the reserve in the seed runs out.
The oldest carbon 14-dated seed that has grown into a plant was a Judean date palm seed about 2,000 years old, recovered from excavations at Herod the Great's palace on Masada in Israel.
It was germinated in 2005.
The largest seed is produced by the Coco de mer, or "double coconut palm", Lodoicea maldivica.
The entire fruit may weigh up to 23 kilograms (50 pounds) and usually contains a single seed.
Origin and evolution
Seeds have been an important development in the reproduction and spread of conifers and flowering plants.
Plants such as mosses, liverworts and ferns do not have seeds, and use unprotected spores and other methods to propagate themselves.
Before the upper Devonian period, land plants, like modern ferns, reproduced by sending spores into the air.
The spores would land and become new plants only in favourable conditions.
Spores have little food stored, and may be just single cells rather than embryos.
The evolution of seeds changed the plant life cycle by freeing plants from the need for external water for sexual reproduction, and by providing protection and nutrients for the developing embryo.
These functions allowed plants to expand beyond the immediate neighbourhood of water sources.
They were able to exploit environments which were drier and more upland.p92 This can be seen by the success of seed plants in important biological niches on land, from forests to grasslands both in hot and cold climates.
The present-day seed plants are the Gymnosperms, with naked seeds, and the Angiosperms with covered seeds, usually fruits.
The first true seeds are from the upper Devonian 370–354 million years ago, which is probably the theatre of their first evolutionary radiation.
The earliest seed-producing trees were in the forests of the Carboniferous period.p112 The seed plants steadily became one of the most important elements of nearly all ecosystems.
A sail is a large piece of cloth on the top of some boats.
The wind goes around the sail and makes the boat move through the water.
The piece that the sail is attached to is called a mast.
Some boats have many sails, and some have only one.
Usually, small boats have only one sail, and bigger boats have more.
Boats with sails are called sailing boats.
There are many different names for different kinds of sailing boats with different kinds of sails.
Before people made boats with engines that used coal or oil, sailing boats were an important way to travel across oceans.
Now they are not so important for transport, but they are still used for recreation and competition.
Sail types
A mainsail is a sail located behind the main mast of a sailing vessel.
A headsail also known as the jib sail, is any sail set forward of the main mast.
A spinnaker or downwind sail (also termed Kite).
Special-purpose sails are often a variation of the three main categories.
A staysail is a fore-and-aft rigged sail whose luff can be attached to a forestay running from a mast to the  bowsprit.
High-performance yachts, in particular some catamarans such as the International C-Class Catamaran, have used or use rigid wing sails, which are said to perform better than traditional soft sails.
In particular, a rigid wing sail was used by Stars and Stripes, the defender which won the 1988 America's Cup, and by USA-17, the challenger which won the 2010 America's Cup.
Most modern yachts, including bermuda rig, ketch and yawl boats, have a sail "inventory" which usually includes more than one of these types of sails.
Although the mainsail is “permanently” hoisted while sailing, headsails and spinnakers can be changed depending on the particular weather conditions to allow better handling and speed.
The quest for the perfect sailshape
The Headsail: YouTube
The Mainsail; YouTube
from or about the country of Spain, such as a person from Spain or food from Spain
Spanish people
the Spanish language
Other use
Skin is the outside covering of mammals and some other animals.
It has many purposes.
First of all, it is a defense against the entry of pathogens such as bacteria and parasites.
Second, it regulates (keeps in control) the body's temperature.
It allows evaporation from its surface, and adjusts it.
It is a physical defense, very strong in some animals, but rather weak in humans.
The skin and hair on mammals has several purposes.
In addition to temperature regulation and defense, some hair is used for signaling.
Most animals add other defenses to their skin.
Mammals have hair or fur on their skin.
Birds have feathers on their skin.
Most fish, and reptiles, like snakes and lizards, have scales on their skin.
Humans can have different skin colours like black people and white people depending on their race and has to do with genetics.
The skin is actually the largest organ of the human body.
Without skin, humans would easily get infected with diseases.
Skin helps regulate body temperature.
Skin lowers the potentially harmful effects of UV rays.
As part of the immune system, skin can help warn people to certain diseases.
Clean skin is important to health, and all mammals groom their hair and skin.
Skin care is much work.
Skins can be made into leather.
Leather is sometimes used to make shoes, bags, and balls.
Other things can be said to have "skins".
People often say that fruits, such as apples, bananas, grapes, kiwis, and strawberrys, and vegetables, such as potatoes, have "skins".
A search engine is a website that allows users to look up information on the World Wide Web (WWW), part of the Internet.
The search engine will achieve this by looking at many web pages to find matches to the user's search inputs.
It will return results ranked by relevancy and popularity by the search engine.
Some popular search-engines are Google Search, Yahoo!
Search, Ask.com, Forestle and Bing.
Older services include Webcrawler, Lycos, and Alta Vista.
To use a search engine you must enter at least one keyword in to the search box.
Usually an on-screen button must be clicked on to submit the search.
The search engine looks for matches between the keyword(s) entered and its database of websites and words.
After the user inputs their search or query into the search bar, a list of results will appear on the screen known as search engine results page (SERP).
This list of webpages contains matches related to the user's query in a particular order determined by a ranking system.
Most search engine will remove "spam" pages from the list of results to provide a better list of results.
The user can then click on any of the links to go to that webpage.
Search engines are some of the most advanced websites on the web.
They use special computer code to sort the web pages on SERPs.
The most popular or highest quality web pages will be near the top of the list.
When a user types words into the search engine, it looks for web pages with those words.
There could be thousands, or even millions, of web pages with those words.
So, the search engine helps users by putting the web pages it thinks the user wants first.
Search engines are very useful to find information about anything quickly and easily.
Using more keywords or different keywords improves the results of searches.
A search service may also include a portal with news, games, and more information besides a search engine.
has a popular portal, and MSN Search is part of the MSN portal, while Google has a simple design on its front page.
Search services usually work without charging money for finding sites, and are often supported with text or banner advertisements.
Search engines use robots to ‘crawl’ online content.
The process of crawling is the first measure that search engines take before indexing content in virtually any form–videos, text, images, webpages, etc..The content may constitute newly uploaded content to the internet or content that features updates or changes to its material.
These robots, also known as crawlers or bots, record the information along with its links.
Once the material has been crawled, it can be stored in a massive URL database.
It’s this database that generates internet search results.
After the bots crawl content, it can be indexed in the database and arranged in terms of its relevance.
If internet content has not been crawled or indexed, it is unlikely to appear in the search results when someone makes a query no matter how relevant that content may be.
After the content has been crawled, each of its words is indexed.
The search engines also pinpoint where words are located on the crawled pages.
During the indexing process, the search engine compares the content to other content with similar ‘words’ and decides how to organize it within its index.
Ranking is a complex process that is dependent on search engine algorithms.
When a searcher makes a query on Google looking for anything from 19th century British landscape painters to New York City plumbers, the search engine will generate a list of good matches to that query.
How these matches appear in the list relates to its rank.
The search engine lists what it ‘thinks’ are the best answers to the query early in its search results.
Google and other search engines rely on algorithms to interpret the searcher’s query, identify the websites and pages in its index that are related to the request, and it then ranks them in terms of relevance in its presented search results list.
What’s important to search engines is to provide searchers with the most relevant matches to their queries as possible.
Website operators, in turn, use search engine optimization to give their pages a higher rank.
Sabbath in Christianity is the day of rest and service to God.
The idea of the Sabbath in Christianity comes directly from the idea
of the Sabbath (or Shabbat) in Judaism.
In fact, the word Sabbath itself comes from the Hebrew word Shabbat.
Like the Jewish Sabbath (Shabbat), the Sabbath in Christianity comes from the Genesis story of Creation.
But unlike Jews, most Christians have Sabbath on Sunday, not Saturday.
They also rest, but not the same way as Jews.
The exact way depends on the church denomination.
Differing views
They say that there is an analogy between the obligation of the Christian day of worship and the Sabbath-day ordinance.
These two rules are not literally identical though.
They say that this ordinance is no longer valid, because God has replaced his old creation by a new one.
For this reason, the obligation to keep the Sabbath is not the same for Christians as for Jews.
They say there are examples in the New Testament, and in other writings surviving from the first few centuries.
Some conservative Christians are "Sabbatarians".
Most of these follow the Reformed traditions.
Sabbatarians think the first day of the week or Lord's Day is the new Sabbath.
This is because the 4th commandment has never been revoked and Sabbath-keeping is in any case a creation ordinance.
Still others believe that the Sabbath remains as a day of rest on the Saturday, reserving Sunday as a day of worship.
In reference to Acts 20:7, the disciples came together on the first day of the week (Sunday) to break bread and to hear the preaching of the apostle Paul.
This is not the first time Christians assembled together on a Sunday; Jesus appeared to the Christians on the "first day of the week" while they were in hiding.
One can maintain this argument in that Jesus himself maintained the Sabbath, although not within the restrictions that were mandated by Jewish traditions;  the Pharisees often tried Jesus by asking him if certain tasks were acceptable according to the Law.
This would seem to show that while the Sabbath was still of importance to the Jews, Sunday was a separate day for worship and teaching from Scriptures.
The Seventh-day Adventists and other churches disagree with some of these views.
They argue that the custom of meeting for worship on Sunday originated in paganism, specifically Sol Invictus and Mithraism (in which sun god worship took place on Sunday).
This is therefore an explicit rejection of the commandment to keep the seventh day holy.
Instead, they keep Saturday as the Sabbath as a memorial to God's work of creation believing that none of the Ten Commandments can ever be destroyed.
Seventh-day Sabbatarians claim that the seventh day Sabbath was kept by the majority of Christian groups until the 2nd and 3rd century, by most until the 4th and 5th century, and a few thereafter, but because of opposition to Judaism after the Jewish-Roman wars, the original custom was gradually replaced by Sunday as the day of worship.
The history of these changes is certainly not altogether lost regardless of any belief in a suppression of the facts by a conspiracy of the pagans of the Roman Empire and the clergy of the Catholic Church.
Jews had come to be hated in the Roman Empire after the Jewish-Roman wars.
This led to the criminalization of the Jewish Sabbath.
Hatred of Jews is apparent in the Council of Laodicea (4th Century AD) where Canon 37–38 states: "It is not lawful to receive portions sent from the feasts of Jews or heretics, nor to feast together with them."
and "It is not lawful to receive unleavened bread from the Jews, nor to be partakers of their impiety."
In keeping with this rejection of the Jews, this Roman council also criminalized the Jewish Sabbath as can be seen in Canon 29 of the Council Laodicea: "Christians must not Judaize by resting on the Sabbath, but must work on that day, rather honoring the Lord's Day; and, if they can, resting then as Christians.
But if any shall be found to be judaizers, let them be excommunicated from Christ."
Liturgical calendar
Statistics is a branch of applied mathematics that deals with collecting, organising, analysing, reading and presenting data.
Descriptive statistics make summaries of data.
Inferential statistics makes predictions.
Statistics helps in the study of many other fields, such as science, medicine, economics, psychology, politics and marketing.
Someone who works in statistics is called a statistician.
In addition to being the name of a field of study, the word "statistics"  can also mean numbers that are used to describe data or relationships.
The first known statistics are census data.
The Babylonians did a census around 3500 BC, the Egyptians around 2500 BC, and the Ancient Chinese around 1000 BC.
Starting in the 16th century mathematicians such as Gerolamo Cardano developed probability theory, which made statistics a science.
Since then, people have collected and studied statistics on many things.
Trees, starfish, stars, rocks, words, almost anything that can be counted has been a subject of statistics.
Collecting data
Before we can describe the world with statistics, we must collect data.
The data that we collect in statistics are called measurements.
After we collect data, we use one or more numbers to describe each observation or measurement.
For example, suppose that we want to find out how popular a certain TV show is.
We can pick a group of people (called a sample) out of the total population of viewers.
Then we ask each viewer in the sample how often they watch the show.
The sample is data that one can see, and the population is data that one cannot see (assuming that not every viewer in the population are asked).
For another example, if we want to know whether a certain drug can help lower blood pressure, we could give the drug to people for some time and measure their blood pressure before and after.
Descriptive and inferential statistics
Numbers that describe the data one can see are called descriptive statistics.
Numbers that make predictions about the data one cannot see are called inferential statistics.
Descriptive statistics involves using numbers to describe features of data.
For example, the average height of women in the United States is a descriptive statistic: it describes a feature (average height) of a population (women in the United States).
Once the results have been summarized and described, they can be used for prediction.
This is called inferential statistics.
As an example, the size of an animal is dependent on many factors.
Some of these factors are controlled by the environment, but others are by inheritance.
A biologist might therefore make a model that says that there is a high probability that the offspring will be small in size—if the parents were small in size.
This model probably allows to predict the size in better ways than by just guessing at random.
Testing whether a certain drug can be used to cure a certain condition or disease is usually done by comparing the results of people who are given the drug against those who are given a placebo.
Most often, we collect statistical data by doing surveys or experiments.
For example, an opinion poll is one kind of survey.
We pick a small number of people and ask them questions.
Then, we use their answers as the data.
The choice of which individuals to take for a survey or data collection is important, as it directly influences the statistics.
When the statistics are done, it can no longer be determined which individuals are taken.
Suppose we want to measure the water quality of a big lake.
If we take samples next to the waste drain, we will get different results than if the samples are taken in a far-away and hard-to-reach spot of the lake.
If there are many samples, the samples will likely be very close to what they are in the real population.
If there are very few samples, however, they might be very different from what they are in the real population.
This error is called a chance error (see also Errors and residuals in statistics).
The individuals for the samples need to be chosen carefully.
Usually, they will be chosen randomly.
If this is not the case, the samples might be very different from what they really are in the total population.
This is true even if a great number of samples is taken.
This kind of error is called bias.
We can reduce chance errors by taking a larger sample, and we can avoid some bias by choosing randomly.
However, sometimes large random samples are hard to take.
And bias can happen if different people are not asked, or refuse to answer our questions, or if they know they are getting a fake treatment.
These problems can be hard to fix.
See standard error for more.
Finding the middle of the data
The middle of the data is called an average.
The average tells us about a typical individual in the population.
There are three kinds of average that are often used: the mean, the median and the mode.
Where  are the data and  is the population size (see also Sigma Notation).
This means that one calculates the mean by adding up all the values, and then divide by the number of values.
For the example above, the mean is:
The problem with the mean is that it does not tell anything about how the values are distributed.
Values that are very large or very small change the mean a lot.
In statistics, these extreme values might be errors of measurement, but sometimes the population really does contain these values.
For example, if there are 10 people in a room who make $10 per day and 1 who makes $1,000,000 per day.
The mean of the data is $90,918 per day.
Even though it is the average amount, the mean in this case is not the amount any single person makes, and thus is not very useful for some purposes.
The mean described above is the "arithmetic mean".
Other kinds are useful for some purposes.
The median is the middle item of the data.
For a given data , this is sometimes written as .
To find the median, we sort the data from the smallest number to the largest number, and then choose the number in the middle.
If there is an even number of data, there will not be a number right in the middle, so we choose the two middle ones and calculate their mean.
In our example above, there are 10 items of data, the two middle ones are "57" and "64", so the median is (57+64)/2 = 60.5.
As another example, like the income example presented for the mean, consider a room with 10 people who have incomes of $10, $20, $20, $40, $50, $60, $90, $90, $100, and $1,000,000.
Here, the median is $55, because $55 is the average of the two middle numbers, $50 and $60.
If the extreme value of $1,000,000 is ignored, the mean is $53.
In this case, the median is close to the value obtained when the extreme value is thrown out.
The median solves the problem of extreme values as described in the definition of mean above.
The mode is the most frequent item of data.
For example, the most common letter in English is the letter "e".
We would say that "e" is the mode of the distribution of the letters.
There can be more than one mode.
For example, if there are 10 people in a room with incomes of $10, $20, $20, $20, $50, $60, $90, $90, $90, $100, and $1,000,000, the modes are $20 and $90.
This is bi-modal, or has two modes.
Bi-modality is very common, and it often indicates that the data is the combination of two different groups.
For instance, the average height of all adults in the U.S. has a bi-modal distribution.
This is because males and females have separate average heights of 1.763 m (5 ft 9 + 1⁄2 in) for men and 1.622 m (5 ft 4 in) for women.
These peaks are apparent when both groups are combined.
Finding the spread of the data
Another thing we can say about a set of data is how spread out it is.
A common way to describe the spread of a set of data is the standard deviation.
If the standard deviation of a set of data is small, then most of the data is very close to the average.
If the standard deviation is large, though, then a lot of the data is very different from the average.
The standard deviation of a sample is generally different from the standard deviation of its originating population .
Because of that, we write  for population standard deviation, and  for sample standard deviation.
If the data follows the common pattern called the normal distribution, then it is very useful to know the standard deviation.
If the data follows this pattern (we would say the data is normally distributed), about 68 of every 100 pieces of data will be off the average by less than the standard deviation.
Not only that, but about 95 of every 100 measurements will be off the average by less than two times the standard deviation, and about 997 in 1000 will be closer to the average by less than three standard deviations.
Other descriptive statistics
Related software
SPSS (made by IBM)
Speed is the distance of a moving object in a given amount of time.
Speed is a measure of how fast something is moving.
The average speed of an object in a certain time is the distance the object travelled divided by the time.
Speed is also the distance covered by an object per unit time.
Finding speed
To find speed ,
where  is the distance and  is the time that has gone by.
Units of measurement for speed
There are many units of measurement for speed.
For example, an object's speed can be measured in
miles per hour (mph),
kilometers per hour (km/h)
meters per second (m/s), which is the SI-unit for speed.
Changing speed
When an object changes speed, it gets faster or slower.
If the speed of the object increases, it is called acceleration.
If the object gets slower, and the speed decreases, it is called deceleration, or negative acceleration.
A server log records what is happening on a server at any time.
For example, an HTTP server runs a web site.
de:Logdatei
In net jargon, a server is a computer that serves many kinds of information to a user or client machine.
Usually a server will only do a few things for many clients.
Every type of thing a server does is called a service.
Services are used by other computers that are called clients.
The relationship between client and server is called a client-server relationship.
For example, Wikipedia has web servers which have a service for sending web pages over the Internet.
Your client computer talks to Wikipedia's web page service to get web pages for you.
A server can also host internet games, share files, and give access to peripheral equipment such as printers.
In simple words, the individual computers are connected to some powerful computers called servers.
These store files and information in the form of website.
With an Internet connection, different users anywhere in the world can access these files.
For servers and clients to talk to each other, they need to be connected to a network.
They need to use the same communication protocol, a set way for machines to talk to other machines.
It is like a language.
For example, the Wikipedia server runs the HTTP to send web sites to your computer, and your computer uses the HTTP Protocol to ask Wikipedia for pages.
Usually, servers are specially made to be more powerful and reliable.
They are usually more expensive than normal computers.
Sometimes, servers can be clustered, which means many servers are working together to do one service.
The server might slow down if there are too many people accessing the server at the same time, resulting in a high load.
An overloaded server might also shut itself down automatically.
In a peer-to-peer system, every computer is both a client and a server to the others.
This is commonly put into file sharing and VOIP.
However, this can help in attempts at piracy.
Typical server operating systems are Linux, FreeBSD, NetBSD, and OpenBSD.
Unlike other computers, a server often has no monitor, keyboard, or mouse.
When a server doesn't have to do very much, server software can run on a computer that is also doing other things.
Examples of web server software include Apache or IIS.
A web server can host one, or many, websites.
The default port for a web server to listen to is port 80 (HTTP) or 443 (HTTPS).
Some web servers do other things than just serving a web page.
For example, they may have something called SSI that makes building a website easier.
Web servers use services like CGI to let software on the server make web pages.
Some of the programming languages that can use CGI are scripting languages like Perl, Python, PHP, or ASP.
Some are compiled languages like C++ or Java.
A simile is a figure of speech that compares two different things, usually by using the words 'like' or 'as'.
It is used to make a direct and clear comparison between two things .Similes may be confused with metaphors, which do the same kind of thing.
Similes use comparisons, with the words 'like' or 'as'.
Metaphors use indirect comparisons, without the words 'like' or 'as'.
Similes:
Like a hungry wolf, he ate the food.
A dragonfly is like a plane: they both fly and cannot close their wings.
He fought like a lion.
The color yellow is like walking into a surprise birthday party.
The other team's quarterback is as big as a redwood tree
Kingda Ka is as green as a pine tree
"On substantiation through transitive relations" is an old manuscript written by the Arabic scholar Sayf al-Din al-Amidi.
He talks about similes.
In politics, a state is a country which has control over a geographic area or territory.
States have three main features:
Control over a geographic area, or territory
A people, the population of the state.
Institutions which have the power to make laws.
There are different forms of government a state may have, for example a republic or a monarchy.
Sometimes states form their own countries.
At other times many states work together to form a country (like the United States).
Most states also have armed forces, civil service, law and police.
Different definitions
The definition above is very broad.
It  is based on ideas by Georg Jellinek (1851-1911).
Other people had other ideas:
Max Weber (1864-1920) had another definition: According to him, a state is a community of people which has "the monopoly to legitimately use physical force within a well-defined area".
Another definition  is form political science: A state is a system of public institutions which are there to regulate the  issues of a society.
Some philiospohers, such as Aristotle, Rousseau and Hegel had a moralistic view: In their opinion, a state arises when individuals reach their goals and that of society.
According to Hegel,  the state is the reason God came into the world; it is the power of reason.
This reason manifests as His will.
Because of the different definitions, there's no universally accepted definition of state.
The one given at the start of the article is now part of international law.
Early states
The earliest states were just human settlements.
A group of farmers and merchants working together could be 'states' since people can control them and protect them.
More organized states could be monarchies such as early Egypt under the Pharaoh.
Following this were larger more military-based states such as the Babylonian Empire or Roman Empire.
The most famous early states, however, were the Ancient Greek city-states.
Some of them had democracy.
From military to modern state
When the military-based state, the Roman Empire, fell, lots of little states were made and each was also military-based and controlled by a king.
These states did not often work together and war raged.
However, once people within the state itself started fighting (what's called a Civil war), the kings had to make peace and start parliaments.
Modern states
Modern states soon started in the late 15th century.
The main states in Europe were:
Spain under the Habsburg
France under the Bourbons
Russia under Catherine the Great and Alexander II of Russia
These states all tried to improve their politics and economy and became more and more like the states today.
They formed proper boundaries for their lands and worked with power within the state itself more, such as the Church or the nobility.
They made armies, tax systems and embassies all to help make them more powerful and stable.
Different types of state
Types of state can be separated into two categories: democracy and dictatorship.
However, just because a group of states are all democratic does not mean that they follow the same rules.
Iran, Pakistan, France, Germany and the United States of America are all states.
Each of them sees itself as a democracy.
Each of them however has a different idea of what democracy really means.
Different states of the same 'category' can also function differently.
For example, two democratic states may be quite different if one has a well-trained police or army while the other does not.
Therefore, the word 'state' only tells us what type of government that state follows (democratic or dictatorship) and does not tell us about the country itself.
Sub-categories of state
There are lots of sub-types of state branching off from democracy and dictatorship.
The main ones are Pluralism, Marxism and Institutionalism.
Pluralism has been very popular in the United States.
It shows the state as a neutral place for settling arguments between other states.
Pluralism tells us that all people are not equal, but still allows each group of people to tell the state what to do.
This type of state is called a polyarchy.
Also in a pluralist state, politics, the military and the economy are all united and work together.
This means that all power in the state is 'diffused' across the people who live there.
Marxism is an ideology advocating for the rights of workers and labourers of society.
It was started by Karl Marx and Friedrich Engels.
Marxism rejects the idea that a state is there to protect business interest, and is definitely not a neutral place for settling arguments.
The main job of a Marxist state is to protect the labour and financial situation of the peasant classes.
With such reforms, a Marxist state focuses on collectivising resources and creating a planned economy to ensure the well-being of the workers.
Both Marxist and Pluralist states have to react to the activities of groups of people in the state itself.
Institutionalist states do not see themselves as 'instruments' to be controlled, they are more just geographical areas.
In this area, the people just form groups themselves.
An institutionalist state can be made up of both Marxist and Pluralist people, both which have the power to control themselves and not influence the other parties of the state.
Anarchism is when a group of people have complete freedom and do not believe in having a state at all.
Anarchists are a lot like Marxists, since they do not believe that all people are equal, but they believe (opposite to Marxists) that a country can work without any organizations in it.
Law and order are not necessary.
Anarchists (such as Bakunin and Kropotkin in the 19th century), often want a form of Marxism but ignoring some of their rules.
They want workers to manage themselves and simply get paid for what they do, rather than getting paid in wages.
List of sovereign states
A stream is a natural flow of water moving across country between banks.
It is smaller than a river.
The primary meaning of stream is a body of water, confined within a bed and banks, and detectably flowing.
Synonyms or related words include river, creek, tributary, run, branch, brook, bourne, wash, and fork.