the-french-artist/wikipedia_20220301.simple_sentence_split huggingface dataset:
Notice that the blue dot in the blue segment of length 3 is placed at position 1, and the blue segment is scaled so that this dot is placed at the end of the red segment (of length 2).
For multiplication by any X, the blue dot will always start at 1 and end at X. This works even if X is smaller than 1, or negative.
Microsoft Corporation is a company that makes computer software and video games.
Bill Gates and Paul Allen founded the company in 1975.
Microsoft makes Microsoft Windows, Microsoft Office (including Microsoft Word), Edge, MSN and Xbox, among others.
Most Microsoft programs cannot be downloaded for free - people have to buy them in a shop or online.
Some products (like the Windows operating system) are often already installed when people buy a new computer.
Microsoft Windows is an operating system, which means that it is the basic software that makes people's computers work and lets other programs work.
The majority of desktop and laptop computers run Windows, and so do some tablet computers and a few smartphones.
The latest version of Windows is Windows 11.
The latest server version is Windows Server 2022.
Microsoft Office is an office suite.
It lets people write documents on their computer with Microsoft Word, make charts and graphs with Microsoft Excel, make presentations with Microsoft PowerPoint, and send email with Microsoft Outlook.
Microsoft SharePoint is a server tool included in Microsoft Office (2007, 2013).
Microsoft Expression series was a web development tool.
Internet Explorer is a piece of software that lets people look at things online (known as browsing) and download things from the Internet.
In 2015, it was replaced by Microsoft Edge.
Microsoft also makes other programs for the Internet.
Many of them are called Windows Live services, with the name Windows Live put in front of the old name of the service, like Windows Live Hotmail.
After 2012, the Windows Live name was less used.
Microsoft Bing is an internet search engine for finding things online.
Bing Maps shows maps.
MS-DOS is the first existing operating system developed by Microsoft, used for primitive computers and terminals.
Minecraft and many other programs have been bought by Microsoft and developed further.
Although Microsoft is best known for its software products, the company also runs a number of web services.
Outlook.com is a webmail service.
When Microsoft created this service in 1996, it was called Hotmail.
It is used to send and receive email, manage a calendar of events and tasks, and a list of contacts (such as phone numbers and email addresses).
OneDrive is a file hosting service.
It was started in 2007 and was called "SkyDrive" at the time.
Users can upload files to a web server and get them on a variety of devices, including PCs and mobile devices.
Skype is a VoIP and social media service.
It was not created by Microsoft, but by a company called Skype SARL, which was later bought out by Microsoft.
The Skype program or mobile app lets people make phone calls through the Internet to other Skype users for free and, for a fee, landline phones.
LinkedIn is a social networking service for people with professional jobs.
Like Skype, it was not created by Microsoft but by another company which Microsoft later bought.
The site lets people post information about their jobs and skills to help employers look for new people to hire.
MSN is a web portal where people can read news and get information about different topics.
It was created in 1995 and at one point its services were made under the brand name of "Windows Live".
MSN used to have an instant messaging service, MSN Messenger, but that has since become part of Skype.
Bing is a search engine similar to Google.
It used to be under the MSN brand and was later known as Live Search, but became its own service in 2009.
Bing is known for the different images that appear on the background of its home page.
Microsoft has also made a wide variety of hardware over the years.
Among them are computer accessories like mice, keyboards, and webcams.
The company also makes and promotes a video game console, Xbox.
It lets people play video games on their televisions.
The games were first stored on CDs, but many recent games are downloaded from the Internet.
There have been three generations of Xbox.
The first generation came out in 2001 and was just called Xbox, while the second, the Xbox 360, was released in 2005.
The third model is the Xbox One in May 2013.
In 2020, Microsoft introduced Xbox Series X and Xbox Series S. Beginning with the Xbox 360, Microsoft introduced Xbox Live, which lets people play games online against other people anywhere in the world.
The Xbox has become very popular and more than 150 million units have been sold worldwide.
Because of this, Microsoft is considered one of the three big companies that make video game consoles, along with Nintendo and Sony.
Most recently, Microsoft has also started to make its own PCs, called the Surface.
The first model was announced in 2012 and the Surface line now includes tablets that use either ARM or Intel processors, two models of laptops called the Surface Book and Surface Laptop, an all-in-one PC called the Surface Studio, and an interactive whiteboard, the Surface Hub.
In 2014, Microsoft bought the mobile phone division of Nokia, a Finnish company, which then became Microsoft Mobile.
The sale included the Lumia family of smartphones, which use Microsoft's own Windows Phone platform.
From 2014 to 2016, Microsoft Mobile also made feature phones with the Nokia brand.
Then the feature phone business was sold to HMD global, which continues to produce  both feature phones and Android smartphones under license from Nokia.
Main Microsoft Website
1975 establishments in the United States
The Islamic World consists of all people who are in Islam.
It is not an exact location, but rather a community.
When they do things together as Muslims, they are the "umma", which means "community" referring to all of the believers.
The faith emphasizes unity and defense of fellow Muslims, so it is common for these nations to cooperate.
Recent conflicts in the Muslim World have sometimes spread because of this desire to cooperate (see below).
It is also likely that some have been made shorter and less damaging because of it.
Some might even have never started.
Muslims are in many countries.
In 52 nations, Muslims are the majority.
Almost all are Sunni.
They speak about 60 languages and come from all ethnic backgrounds.
10.4 million Muslims in Canada and the United States
2.2 million Muslims in Latin and Central America
10.0 million Muslims in the European Union plus Bosnia-Herzegovina and Albania
few or none in Eastern Europe, Norway
62.4 million Muslims in Turkey
284.4 million Muslims in the Arab League including Iraq (with about 15 million Shia, 60% of the population)
254.0 Muslims in Sub-Saharan Africa
65.4 million Muslims (90% Shia) in Iran
48.5 million Muslims in Central Asia - in Azerbaijan, Uzebekistan, Tajikistan, Kazakhstan, Kyrgyzstan, Turkmenistan - formerly republics of the Soviet Union.
26.7 million Muslims in Russia
22.7 million Muslims in Afghanistan
230.0 million Muslims in Pakistan and Bangladesh (formerly East Bengal provincial region).
133.3 million Muslims in India (included Jammu and Kashmir) - the world's largest minority population
133.1 million Muslims in China - a close second
34.6 million Muslims in Somalia
196.3 million Muslims in Indonesia
30.0 million Muslims in the rest of South-East Asia, especially Malaysia
few or none in Japan, Australia, New Zealand, Mongolia, or the South Pacific
1.5 billion people total
The Al-Jazeera satellite TV network in the Arabic language is a news source many Muslims watch.
In most Muslim nations, the government is the main source of news.
This sometimes makes it very difficult or dangerous to make anti-government statements.
Islam in law and ethics
Islamic law exists in many variations - in Arabic it is called shariah - five schools of which were created centuries ago.
These are the classical fiqh: the Hanafi school from India, Pakistan and Bangaladesh, West Africa, Egypt, the Maliki in North Africa and West Africa, the Shafi in Malaysia and Indonesia, the Hanbali in Arabia, and Jaferi in Iran and Iraq - where the majority is Shia.
All five are very old and many Muslims feel a new fiqh must be created for modern society.
Islam has a method for doing this, al-urf and ijtihad are the words to describe this method, but they have not been used in a long time, and few people are trusted enough to use them to make new laws.
Muslim women often dress extremely modestly, and many do so by choice.
But in some countries they have been forced to do so against their will.
This is one of the things that causes tension between the Western World and that of Muslims.
Islamic economics bans debt but in most Muslim countries Western banking is allowed.
This is another issue that many Muslims have with the Western world.
Islam in politics
Many people in these countries also see Islam as a political movement.
In democratic countries there is usually at least one Islamic party.
Political Islam is powerful in all Muslim-majority countries.
Islamic parties in Pakistan and Algeria have taken power.
Many in these movements call themselves Islamists, which also sometimes describes more militant Islamic groups.
The relationships between these groups and their views of democracy are complex.
Conflicts with Israel and the US
Some Muslims see this as a fight against Judaism or Jews, but not all.
In Morocco for instance, the Islamists recently invited Jews to join the party.
Jewish groups also cooperate with Arabs in the West Bank, where Neturei Karta (anti-Zionist orthodox Jewish) leader Rabbi Mosche Hirsch served as the Minister for Jewish Affairs in the Fatah before there was a Palestinian Authority.
Like the Arabs, this small group of Jews thought the way Israel was created was not right.
However, very few Jews believe this, and most support Israel as a state.
In 1979 there was a big shift in the way the Muslim world dealt with the rest of the world.
In that year, Egypt made peace with Israel, Iran became an Islamic state after a revolution, and there was an invasion of Afghanistan by the Soviet Union.
A lot of things changed in that year.
By 2001 the Soviet Union was gone, Jordan had also made peace with Israel, and on September 11, 2001 there were major attacks on the U.S. - which most people believe were made to drive the United States out of the Muslim world, especially Saudi Arabia.
In many ways the events of 1979 led to the events of 2001.
The 2001 invasion of Afghanistan and 2003 invasion of Iraq are called part of a War on Terrorism by the United States.
Many or most Muslims see it as a War on Islam.
After the invasion, the Islamic parties won more seats, and a majority of Muslims polled in many nations expressed support for Osama bin Laden and said he would "do the right thing".
Olivier Roy is a French scholar who thinks that this does not express support for al-Qaeda or militant Islam but opposing colonialism and what many Muslims call racism - favourable treatment for Jews especially those living in West Bank settlements, many of whom have American or British passport, and which the United Nations says have no right to live there.
The Organization of Islamic Conference formed in 1969 lets the Muslim nations work as a group.
Russia joined in 2003.
OPEC is another forum where issues between the Muslim and non-Muslim world come up.
In 1973 to protest U.S. support for Israel there was an oil embargo which caused the 1973 energy crisis.
A multiverse is the theory of a conjectured set of multiple possible universes, including ours, which make up reality.
These universes are sometimes called parallel universes.
A number of different versions have been considered.
The cosmological multiverse
The cosmological multiverse tries to explain why the universe we observe i.e. ''our universe'' seems so welcoming to the emergence of life.
Even small changes to the way physics works would make life impossible.
In a multiverse a vast number of universes are randomly created and some happen to favour life emerging there.
Many inhospitable universes would also have been created, but there would be no life there to observe their existence.
The quantum multiverse
The quantum multiverse is another version in which our universe splits into alternative futures with every quantum event.
This is called many-worlds interpretation of quantum mechanics.
The mechanistic paradigm, also known as the Newtonian paradigm, assumes that things in the environment around humans are more like machines than like life.
It was more common in the 19th century.
This is a set of loosely related beliefs that affects all sciences:
In physics it presents atoms as made of particles in preference to say the wave theory of light.
In fact, both the particle and wave view are required to explain everything light does, but are rarely presented as equals.
Many physics students graduate fully understanding the hydrogen bomb but having no clear idea of how musical instruments work.
In astrophysics it assumes that the universe is like clockwork and works on its own without our choice making any difference - this fits relativity but is not easy to combine with quantum mechanics.
In cosmology it accepts models of our universe more easily if reject the continuous creation of matter, energy or any new "other universes".
In chemistry it assumes that molecules are like building blocks, and have no unpredictable or strange and unique effects when combined.
This is the basic assumption of mechanosynthesis which some scientists think will create a molecular assembler.
In biology it assumes that everything about life - all of biochemistry - is predictable from chemistry and physics.
Believers tend to regard ecology and psychology as "less scientific" than physics, chemistry and biology.
Believers may reject ideas like psychoneuroimmunology, Gaia philosophy or Fecund universes for no scientific reason, simply because these theories assume "higher level phenomena" sometimes drive lower levels.
Greedy Reductionism may be more likely among believers in mechanistic ideas.
For instance, they may want to always see things as made of smaller, even invisible, parts that no one can see or prove is real - like in string theory.
For this reason, when they work in psychology, they may prefer theories like behaviorism that deny free will and try to explain human behaviour as a function of biology.
The philosophy of mathematics of most believers is a form of Platonism.
This assumes there is a perfect or ideal form that theories only approximate.
This lets them explain inaccuracies in mechanistic theories as being due to an imperfection in human ability to reason, instead of imperfections in math itself.
Believers in this paradigm sometimes say that those who do not believe in it are following a cognitive paradigm - but almost no one uses this term, since it is redundant - cognitive science is already accepted as the most basic idea in the philosophy of science.
But mechanists reject some of the ideas of cognitive scientists, like cognitive science of mathematics.
Mechanistic thinking also assumes that philosophy of perception is much less important than cognitive scientists say it is - that humans and their beliefs and equipment do not generally add a lot of bias to a scientific theory.
Thomas Kuhn said otherwise, that these things matter, and that the major assumptions of science, can shift drastically.
This he called a paradigm shift.
The shift from mechanistic to cognitive paradigm is an example of this.
Later he used other words to describe the assumptions and beliefs, like mind-set, but the word "paradigm" is still used.
Some say it is much over-used.
Economics is often said to "suffer from" assumptions of the mechanistic paradigm.
Sometimes those who believe in neoclassical economics and also in the mechanistic paradigm say they "seek to unify physics and economics," as if people and particles behaved as two examples of the same kind of thing.
Technology is often easier to make if people accept a mechanistic paradigm - but it may be harder to say why it does not work, if one believes in these ideas.
For instance, creating diagnostic trees might be easier if one works from experience, not from an idea of how a technology should or must work.
A controversial idea is that mechanistic ideas are just an older idea called scholasticism, with more mathematics.
Both tried to work from what should or must be, instead of what experiment seemed to show.
Another controversial idea is that scientism, belief in science as if it were a religion or ethical tradition, comes from this paradigm.
Most scientists who are mechanistic do not say they see science as a guide to ethics, but try to keep them separate.
MediaWiki is the name of the software that runs all of the Wikimedia projects and many more].
MediaWiki was released in 2003.
It is free server-based software which is licensed under the GNU General Public License (GPL).
The software is licensed under the GPL.
This means it is free content, or open source.
MediaWiki is designed to be run on a large web server farm for a website that gets millions of hits per day.
MediaWiki is a very powerful, scalable software and a feature-rich wiki implementation, that uses PHP to process and display data stored in its MySQL database.
Pages use MediaWiki's Wikitext format, so that users without knowledge of XHTML or CSS can edit them easily.
When a user submits an edit to a page, MediaWiki writes it to the database, but without deleting the previous versions of the page, thus allowing easy reverts in case of vandalism or spamming.
MediaWiki can manage image and multimedia files, too, which are stored in the filesystem.
For large wikis with lots of users, MediaWiki supports caching and can be easily coupled with Squid proxy server software.
All Wikimedia projects run on MediaWiki version  .
Because MediaWiki is flexible, many websites that want people to contribute information use MediaWiki rather than other types of wiki software.
Those operated by Fandom are among them.
In MediaWiki, a system administrator can choose to install extensions which are provided on the main MediaWiki website.
Some are from the MediaWiki developers, while others are from programmers from all around the world.
Most extensions can be download from Wikimedia's Subversion repository.
However, there are some other extensions that other people host themselves.
Some extensions had been added to the main software along the development of MediaWiki.
For example, the Makesysop extension is an extension to promote a user into an administrator or a bureaucrat.
Article (No namespace, like this page)
Talk – for main namespace talk page
User – the user page, also from Special:MyPage
User talk – the user talk page, also from Special:MyTalk
Project – The project namespace (like on this wiki, is Wikipedia)
Project talk – The project page talk page
File – Page for images and sounds
File talk – Talk about the media
MediaWiki – Software pages, can only be changed from an administrator
MediaWiki talk – Talk about the software page, anyone can write in this namespace
Template – for templates
Template talk – talk about the template
Help – Help pages (like Help:Contents)
Help talk – talk about the help page
Category - Categorising pages
Category talk – talk about the category
Special – Special pages of the MediaWiki software
Media – Namespace to directly link to the file
Additional namespaces can be added using the settings file from the installation of MediaWiki.
As MediaWiki is a complex software, there would always be bugs in the software, especially for new extensions.
Therefore, Wikimedia has created a Bugzilla website for people who see a bug to tell the developers of MediaWiki.
Some extensions of MediaWiki use the Wikimedia Bugzilla, while some just use the talk pages of the extension page.
Users can customize MediaWiki for different appearance.
They may use one of the several "skins".
At different times different skins have been default.
For example, Wikipedia once used Monobook before adopting the new Vector skin in version 1.16.
More information about the software:
Main MediaWiki website
MediaWiki on Meta Wiki
MediaWiki User's Guide on Meta Wiki
PHP script FAQ
PHP script automatic wikification (former feature)
How to become a MediaWiki hacker (installation advice)
Wikitech-L mailing list (technical discussions regarding the development)
Sites using MediaWiki
Sourceforge: MediaWiki Project page Now changed to MediaWiki.org.
Sourceforge: MediaWiki Bug reports Now changed to Wikimedia Bugzilla.
Sourceforge: MediaWiki Feature requests Now changed to Wikimedia Bugzilla.
Translatewiki.net – The place to translate MediaWiki messages.
Websites established in 2002
A first language (also mother language, mother tongue, native language, arterial language, or L1) often means the language that a person learns first.
It helps one understand words and concepts in the style of that language.
Sometimes, but not often, first language means the language that a person speaks best (the second language is then spoken less well than the first language, etc.).
In that sense, a person could have more than one first or second language.
The hair that grows on the upper lip of some men is called a mustache.
The hair that grows on the sides of the face and the chin of some men is called a beard.
Some men have a lot of hair and a big mustache, and some have very little.
In the modern world, many men shave part or all of their mustaches, or cut their mustache so it does not get very long.
A chin beard with no mustache is called a goatee, whilst a chin beard with a mustache is known as a Van Dyke.
The earliest facial hair above the lip, as a style, is credited to the Iron Age Celts.
Diodorus Siculus, a Greek historian,wrote this about the Celtic people:
A mile is a unit of length.
There are many different kinds of mile but mile on its own usually means the statute mile.
Statute mile
In the US and the UK the word mile usually means the statute mile.
Nautical mile
The nautical mile was originally defined as one minute of arc along a line of longitude of the Earth.
There are 60 minutes of arc in one degree or arc (60' = 1°).
So there were 10,800 nautical miles from the North Pole to the South Pole.
|1 nautical mile||= 1,852 metres (by definition)
|||≈  feet
|||≈  statute miles
Roman mile
The mile was first used by the Romans.
It comes from the Latin phrase mille passus (plural: milia passuum).
This means "one thousand paces".
A pace is the distance each foot moves when taking one step.
|1 Roman mile||= 1,000 Roman paces (by definition)
|||≈ 1,479 metres
|||≈ 4,852 feet
Other miles
Different miles have been used throughout history in various parts of the world.
In Norway and Sweden, for example, a mil is a unit of length which is equal to 10 kilometres.
Even in English-speaking countries that use the metric system (for example, Australia, Canada, and New Zealand), the mile is still used in many idioms.
A country mile is used colloquially to mean a very long distance.
"A miss is as good as a mile" (failure by a narrow margin is no better than any other failure)
"Give him an inch and he'll take a mile" – a corruption of "Give him an inch and he'll take an ell" (the person in question will become greedy if shown generosity)
"Missed by a mile" (missed by a wide margin)
"Go a mile a minute" (move very fast)
"Talk a mile a minute" (speak very fast)
"To go the extra mile" (to put in extra effort)
"Miles away" (lost in thought, or daydreaming)
"Milestone" (an event showing a lot of progress)
Margarine is an artificial butter.
It can be made from vegetable oil, or animal fat.
It may also contain skimmed milk, salt and emulsifiers.
Margarine is used in many baked products.
It contains less fat than butter, so is often chosen instead of it.
There are also "low fat" margarines, which contain even less fat.
However, many types of margarine are made with hydrogenated oils.
Products with hydrogenated oil have trans fats, which are unhealthy and can cause heart disease.
Other fats, like olive oil, and butter, are a better choice for cooking.
The Milky Way is our home galaxy.
It contains over 200 billion stars, including our Sun.
The Milky Way has a diameter of about 170,000 or 200,000 light years, and is a barred spiral galaxy.
The idea that the Milky Way is made of stars goes back to the Ancient Greek philosopher Democritus.
The Milky Way has three main parts:  a disk, where the Solar System is, a bulge at the core, and an outer halo all around it.
Although the word "disk" suggests it is flat, the Milky Way is actually not quite flat.
It is slightly warped and twisted.
This galaxy belongs to the Local Group of three large galaxies and over 50 smaller galaxies.
The Milky Way is one of the largest galaxies in the group, second to the Andromeda Galaxy.
Its closest neighbour is the Canis Major Dwarf Galaxy, which is about 25,000 light years away from the Earth.
The Andromeda Galaxy is moving towards the Milky Way Galaxy, and will collide with it in about 3.75 billion years.
The Andromeda Galaxy moves with a speed of about 1,800 kilometres per minute.
The stellar disk of the Milky Way Galaxy is about 200,000 light-years (9×1017 km) in diameter, and is considered to be, on average, about 1000 light years thick.
It is estimated to contain at least 100 billion stars, and possibly up to 400 billion stars.
The figure depends on the number of very low-mass, or dwarf stars, which are hard to detect, especially more than 300 light years from our sun.
Therefore, present estimates of the total number are uncertain.
This can be compared to the one trillion (1012) stars of the neighbouring Andromeda Galaxy.
The stellar disc of the Milky Way does not have a sharp edge, a radius beyond which there are no stars.
Rather, the number of stars drops smoothly with distance from the centre of the Galaxy.
Beyond a radius of about 40,000 light years, the number of stars drops much faster, for reasons that are not understood.
Extending beyond the stellar disk is a much thicker disk of gas.
Recent observations indicate that the gaseous disk of the Milky Way has a thickness of around 12000 light years–twice the previously accepted value.
As a guide to the relative physical scale of the Milky Way, if the Solar System out to the orbit of Pluto were reduced to the size of a US quarter (about an inch or 25 mm in diameter), the Milky Way would have a diameter of 2,000 kilometers.
At 220 kilometers per second it takes the Solar System about 240 million years to complete one orbit of the Galaxy (a galactic year).
The Galactic halo extends outward, but is limited in size by the orbits of two Milky Way satellites, the Large and the Small Magellanic Clouds, whose closest approach is at about 180,000 light years.
At this distance or beyond, the orbits of most halo objects would be disrupted by the Magellanic Clouds, and the objects would likely be ejected from the vicinity of the Milky Way.
Galactic center
The exact distance from the Sun to the galactic center is debated.
The latest estimates give distances to the Galactic center of 25–28,000 light years.
Movement of material around the galactic center shows that it has a compact object of very large mass.
The intense radio source named Sagittarius A*, thought to mark the center of the Milky Way, is now confirmed to be a supermassive black hole.
Most galaxies are believed to have a supermassive black hole at their center.
The nature of the galaxy's bar is also actively debated, with estimates for its half-length and orientation spanning from 3,300–16,000 light years (short or a long bar) and 10–50 degrees.
Viewed from the Andromeda Galaxy, it would be the brightest feature of our own galaxy.
In Greek mythology, Zeus places his son (the baby Heracles) whose mother was a mortal woman on Hera's breast while she is sleeping so that the baby will drink her divine milk and become immortal.
However, Hera wakes up while she is breastfeeding the baby and realizes she is nursing a baby she does not know.
According to Greek mythology, she then pushes the baby away and a stream of her milk sprays the night sky, making a faint band of light known as the Milky Way.
Spiral galaxies
Local galaxies
Movement, or motion,  is the state of changing something's position or changing where something is.
A bird that is flying is moving.
So is a person who is walking.
This is, because they change where they are.
They "move" from one place to another.
There are many forms of science and mathematics that are related to movement.
Because of the work of scientists including Galilei and Newton, we know that position is relative.
This means that an object's position depends on where it exists in relation to other objects.
For example, a ball can be  away from a box,  from a chair and away from a table.
Here, the box, chair and the table helped to define the position of the ball.
They acted as the reference points for the observation of the ball.
By telling someone how far the ball was from other objects, they were told its relative position.
THe motion of an oj=bject is also relative.
It depends on how its position changes in relation to other objects.
A person is sitting inside a train (Train A).
The train has not started moving yet.
When that person looks out the window, they see another train (Train B) .
Both trains are facing the same direction.
If Train B moves backwards, it appears to the person on TRain A that they are moving toward Train B. If a reference point it added this can be changed.
If the person can also see a pole next to the trainsm they will see that train A did not move and train B moved backwards.
From this, it is shown that what the movement is can not bo known without a frame of reference.
In this example the pole is the frame of reference.
The study of motion without considering its cause is called kinematics.
Kinematics deals with terms like speed, velocity, and acceleration.
Dynamics is the branch of physics that focuses on the causes and effects of motion.
It deals with force, inertia, work, energy and momentum.
Animal movement
The movement of animals is controlled by the nervous system, especially the brain and spinal cord.
The muscles that control the eye are driven by the optic tectum in the midbrain.
All the voluntary muscles in the body are controlled by motor neurons in the spinal cord and hindbrain.
Spinal motor neurons are controlled by neural circuits of the spinal cord, and by inputs from the brain.
The spinal circuits do many reflex responses, and also do rhythmic movements such as walking or swimming.
The descending connections from the brain give more sophisticated control.
The brain has several areas that project directly to the spinal cord.
At the highest level is the primary motor cortex.
This is a strip of tissue at the back of the frontal lobe.
This tissue sends a massive projection directly to the spinal cord, through the pyramidal tract.
This allows for precise voluntary control of the fine details of movements.
There are other brain areas which affect movement.
Among the most important secondary areas are the premotor cortex, basal ganglia, and cerebellum.
In addition, the brain and spinal cord controls the autonomic nervous system.
this system works by secreting hormones and by modulating the "smooth" muscles of the gut.
The autonomic nervous system affects heart rate, digestion, respiration rate, salivation, perspiration, urination, sexual arousal and several other processes.
Most of its functions are not under direct voluntary control.
Several of them, such as respiration, can be controlled directly as well.
Metaphor  is a term for a figure of speech.
It does not use a word in its basic literal sense.
Instead, it uses a word in a kind of comparison.
We run, and we also say rivers run.
We may run into trouble, especially if we run up a bill at the bar.
So a metaphor uses words to make a picture in our mind.
It takes a word from its original context, and uses it in another.
"I beat him with a stick" = literal meaning of 'beat'.
"I beat him in an argument" = metaphorical meaning of 'beat'.
Metaphors are an essential part of language: it is not possible to speak or write without them.
A simple example is the word "run".
This has a basic meaning of "moving quickly" or "go with quick steps on alternate feet, never having both feet on the ground at the same time".
The Concise Oxford Dictionary then gives
34 other uses as a verb; 21 uses as a noun; about 50 uses in short phrases.
All of these are metaphors, although we do not usually notice this.
We use metaphors to make indirect comparisons, but without using 'like' or 'as' – because that would be a simile.
A simile is a direct comparison: "Jane is like a child".
A metaphor very often uses the verb 'to be': "love is war", for example, not "love is like war" (that is a simile).
Spam is an example that any email user knows about – this word was originally a metaphor, from 'Spam', a type of canned meat.
Servers putting unwanted email into somebody's inbox was similar to waiters putting unwanted Spam into food.
This was originally suggested by a Monty Python scene.
When we use a metaphor very often and we forget the old meaning, or forget that the two meanings are connected, this is a 'dead metaphor'.
Originally metaphor was a Greek word for 'transfer'.
It came from meta ('beyond') and pherein ('carry').
So the word metaphor in English was a metaphor, too.
Today in Greek, metaphor is a trolley (a thing that is pushed for carrying shopping or bags).
Most metaphors are concepts:  see conceptual metaphor.
Idioms use metaphors, or are metaphors: for example, the English phrase to kick the bucket means to die.
Simple metaphors
A simple metaphor has a single link between the subject and the metaphoric vehicle.
The vehicle thus has a single meaning which is transferred directly to the subject.
Cool down! [
Cool = temperature]
He was mad. [
mad = anger]
I'll chew on it. [
chew = think]
It was raining cats and dogs. [
cats and dogs = rain]
Max was an angel. [
angel = lovely person]
Complex metaphors
A complex metaphor happens where a simple metaphor is based on a secondary metaphoric element.
For example, using a metaphor of 'light' for 'understanding' may be complexified by saying 'throwing light' rather than 'shining light'. '
Throwing' is an extra metaphor for how light arrives.
That lends weight to the argument.
They stood alone, frozen statues on the plain.
The ball happily danced into the net.
"But at my back I always hear / Time's wingèd chariot hurrying near / And yonder all before us lie / Deserts of vast eternity".
From 17th century English poet Andrew Marvell's poem To His Coy Mistress.
Compound metaphors
A compound metaphor is one where there are multiple parts in the metaphor that are used to snag the listener.
These parts may be enhancement words such as adverbs, adjectives, etc.
for Morning in the Bowl of NightHas flung the stone that puts the stars to flight.
An aged man is but a paltry thing,
A tattered coat upon a stick..."
Thick, primal, blind fog descended before his eyes.
The car screeched in hated anguish, its flesh laid bare in the raucous collision.
Compound metaphors are like a multiple punch, hitting the listener repeatedly with metaphoric elements.
Where the complex metaphor uses stacked layers to enhance the metaphor, the compound metaphor uses sequential words.
The compound metaphor is also known as a loose metaphor.
Live and dead metaphors
A live metaphor is one which a reader notices.
A dead metaphor is one no-one notices because it has become so common in the language.
Two people walk off a tennis court.
Someone asks the loser: "What happened?".
"He won".
Literal truth.
"He beat me".
Obviously a dead metaphor.
"He thrashed me".
This one is slightly alive.
The river runs.
Dead, and many variations on this theme.
Electricity is a fluid.
Nearly dead.
All our efforts are running into the sand''.
A short history of metaphor.
Rhetorical figures in sound:
Metabolism is the chemical reactions which keep us alive.
It happens in the cells of living organisms.
The chemical reactions are catalyzed by enzymes.
Metabolism allows organisms to grow, reproduce, maintain their structures, and respond to their environments.
The word ‘metabolism’ can also refer to digestion and the transport of substances into and between different cells.
Metabolism is usually divided into two categories:
Catabolism breaks down organic matter and harvests energy by way of cellular respiration.
Anabolism uses energy to build molecules such as proteins and nucleic acids.
The chemical reactions of metabolism are organized into metabolic pathways, or cycles, like the Krebs cycle.
One chemical is transformed through a series of steps into another chemical by a series of enzymes.
The metabolic system of an organism decides which substances it finds nutritious and which poisonous.
For example, some prokaryotes use hydrogen sulfide as a nutrient, yet this gas is poisonous to animals.
The speed of metabolism, called the metabolic rate, influences how much food an organism will need, and how it is able to get that food.
A striking feature of metabolism is the similarity of the basic metabolic pathways and components between even vastly different species.
For example, the set of carboxylic acids that are best known as the intermediates in the citric acid cycle are present in all known organisms, being found in species as diverse as the unicellular bacterium Escherichia coli and huge multicellular organisms like elephants.
These striking similarities in metabolic pathways are likely due to their early appearance in the evolution of life, and kept because of their efficiency.
A microscope is a scientific instrument.
It makes small objects look larger.
This lets people see the small things.
People who use microscopes frequently  in their jobs include doctors and scientists.
Students in science classes such as biology also use microscopes to study small things.
The earliest microscopes had only one lens and are called simple microscopes.
Compound microscopes have at least two lenses.
In a compound microscope, the lens closer to the eye is called the eyepiece.
The lens at the other end is called the objective.
The lenses multiply up, so a 10x eyepiece and a 40x objective together give 400x magnification.
Microscopes make things seem larger than they are, to about 1000 times larger.
This is much stronger than a magnifying glass which works as a simple microscope.
Types of microscopes
There are many types of microscopes.
The most common kind of microscope is the compound light microscope.
In a compound light microscope, the object is illuminated: light is thrown on it.
The user looks at the image formed by the object.
Light passes through two lenses and makes the image bigger.
The second most common kind are a few kinds of electron microscopes.
Transmission electron microscopes (TEMs) fire cathode rays into the object being looked at.
This carries information about how the object looks into a magnetic "lens".
The image is then magnified onto a television screen.
Scanning electron microscopes also fire electrons at the object, but in a single beam.
These lose their power when they strike the object, and the loss of power results in something else being generated—usually an X-ray.
This is sensed and magnified onto a screen.
Scanning tunneling microscopes were invented in 1984.
A fluorescence microscope is a special kind of light microscope.
In 2014, the Nobel Prize in Chemistry was awarded to Eric Betzig, William Moerner, and Stefan Hell for "the development of super-resolved fluorescence microscopy".
The citation says it brings "optical microscopy into the nanodimension".
Microscopy Information Information relating to optics, techniques and specimen preparation for teachers, students, amateur scientists.
The mass of an object is a measure of the amount of matter in a body.
A mountain has typically more mass than a rock, for instance.
Mass should not be confused with the related but quite different concept of weight.
We can measure the mass of an object if a force acts on the object.
If the mass is greater, the object will have less acceleration (change in its motion).
This measure of mass is called inertial mass because it measures inertia.
A large mass like the Earth will attract a small mass like a human being with enough force to keep the human being from floating away. "
Mass attraction" is another word for gravity, a force that exists between all matter.
When we measure the force of gravity from an object, we can find its gravitational mass.
Tests of inertial and gravitational mass show that they are the same or almost the same.
Units of mass
The unit of mass in the International System of Units is the kilogram, which is represented by the symbol 'kg'.
Fractions and multiples of this basic unit include the gram (one thousandth of a kg, symbol 'g') and the tonne (one thousand kg), amongst many others.
In some fields or applications, it is convenient to use different units to simplify the discussions or writings.
Atomic physicists deal with the tiny masses of individual atoms and measure them in atomic mass units.
Jewelers normally work with small jewels and precious stones where masses are traditionally measured in carats, which correspond to 200 mg or 0.2 g.
The masses of stars are very large and are sometimes expressed in units of solar masses.
Traditional units are still in encountered in some countries: imperial units such as the ounce or the pound were in widespread use within the British Empire.
Some of them are still popular in the United States, which also uses units like the short ton (2,000 pounds, 907 kg) and the long ton (2,240 pounds), not to be confused with the metric tonne (1,000 kg).
Conservation of mass and relativity
Mass is an intrinsic property of the object: it does not depend on its volume, or position in space, for instance.
For a long time (at least since the works of Antoine Lavoisier in the second half of the eighteen century), it has been known that the sum of the masses of objects that interact or of the chemicals that react remain conserved throughout these processes.
This remains an excellent approximation for everyday life and even most laboratory work.
However, Einstein has shown through his special theory of relativity that the mass m of an object moving at speed v with respect to an observer must be higher than the mass of the same object observed at rest m0 with respect to the observer.
The applicable formula is
where c stands for the speed of light.
This change in mass is only important when the speed of the object with respect to the observer becomes a large fraction of c.
Advanced topics:
Higgs field.
It is the closest planet to the sun.
It makes one trip around the Sun once every 87.969 days.
Mercury is bright when we can see it from Earth.
It has an apparent magnitude ranging from −2.0 to 5.5.
It cannot be seen easily because it is usually too close to the Sun.
Because of this, Mercury can only be seen in the morning or evening twilight or when there is a solar eclipse.
Less is known about Mercury than about other planets of our Solar System.
Even with telescopes only a small, bright crescent can be seen.
It is also hard to put a satellite in orbit around it.
Two spacecraft have visited Mercury.
The first one was Mariner 10.
It only made a map of about 45% of the Mercury's surface from 1974 to 1975.
The second is the MESSENGER spacecraft, which finished mapping Mercury in March 2013.
Mercury looks like Earth's Moon.
It has many craters and smooth plains.
It has no moons and no atmosphere as we know it.
However, Mercury does have an extremely thin atmosphere, known as an exosphere.
Mercury has a large iron core.
Because of this Mercury has a magnetic field about 1% as strong as that of the Earth.
It is a very dense planet because its core is very big.
Temperature at the surface can be anywhere from about 90 to  (−183 °C to 427 °C, −297 °F to 801 °F), with the subsolar point being the hottest and the bottoms of craters near the poles being the coldest.
Known sightings of Mercury date back to at least the first millennium BC.
Before the 4th century BC, Greek astronomers thought that Mercury was two different objects: The one that they were only able at sunrise, they called Apollo; the other one that they were only able to see at sunset, they called Hermes.
The English name for the planet is from the Romans, who named it after the Roman god Mercury.
The symbol for Mercury is based on Hermes' staff.
Even though Mercury is the closest planet to the Sun, it is not the hottest.
This is because it has no greenhouse effect.
The heat that the Sun gives it, quickly escapes into space.
The hottest planet is Venus.
Inside Mercury
Mercury is one of four inner planets in the Solar System.
It is a terrestrial planet like Earth.
It is the smallest planet in the Solar System.
It has a radius of .
Mercury is even smaller than some of the largest moons in the solar system, such as Ganymede and Titan.
However, it has greater mass than the largest moons in the solar system.
Mercury is made of about 70% metallic and 30% silicate material.
Mercury has the second highest density in the Solar System at 5.427 g/cm³, only a little bit less than Earth’s.
Surface of Mercury
Mercury's surface looks like the surface of the Moon.
It has plains that look like mares and has lots of craters.
Mercury was hit by a lot of comets and asteroids 4.6 billion years ago.
Mercury was also hit during a period called the Late Heavy Bombardment.
Mercury has lots of craters because it does not have any atmosphere to slow objects down.
Images gotten by MESSENGER have shown that Mercury may have shield volcanoes.
The surface temperature of Mercury ranges from 100 to 700 K (−173 to 427 °C; −280 to 800 °F) at the most extreme places.
Even though the temperature at the surface of Mercury in the day is very high, observations suggest that there is frozen water on Mercury.
Mercury is too small and hot for its gravity to keep any thick atmosphere for a long time.
It does have a thin exosphere that is made up of hydrogen, helium, oxygen, sodium, calcium, potassium.
This exosphere is blown away and replenished from lots of sources.
Hydrogen and helium may come from the solar wind.
Radioactive decay of elements inside the crust of Mercury is another source of helium, and also sodium and potassium.
Orbit and rotation
Mercury has the most eccentric orbit of all the planets in the Solar System.
It has an eccentricity of 0.21.
It ranges from 46,000,000 to 70,000,000 km (29,000,000 to 43,000,000 mi) away from the Sun.
Mercury takes 87.969 Earth days to go around the Sun.
Mercury's axial tilt is 0.027 degrees.
In the future, because Mercury's orbit's is very eccentric and Jupiter's huge gravity, its orbit may become unstable and the following things may happen:
It crashes into the Sun
It enters the Sun's Roche limit slowly and is torn apart
It crashes into Venus
It crashes into Earth
It is flung out of the Solar System and becomes a rouge planet
List of satellites sent to Mercury
Many man-made satellites have been sent to Mercury to study it.
The first spacecraft to visit Mercury was NASA's Mariner 10.
It stayed in Mercury's orbit from 1974–1975.
Mariner 10 took the first close-up pictures of Mercury's surface.
It showed many features, such as the craters.
Unfortunately, the same side of Mercury was day each time Mariner 10 flew close to Mercury.
This made observing of both sides of Mercury impossible.
In the end, less than 45% of the Mercury's surface was mapped.
Mariner 10 came close to Mercury three times.
At the first time, it found a magnetic field, which surprised planetary geologists because Mercury's rotation was too slow to create a magnetic field.
The second time was mainly used to take pictures of Mercury's surface.
At the third time, it got more information about the magnetic field.
It showed that the Mercury's magnetic field is like the Earth's magnetic field.
On March 24, 1975, eight days after its last close fly by, Mariner 10 ran out of fuel.
Because its orbit could no longer be controlled, mission controllers shut down the probe .
Mariner 10 is thought to still be orbiting the Sun.
The second satellite to visit Mercury is NASA's MESSENGER.
It stands for MErcury Surface, Space ENvironment, GEochemistry, and Ranging.
It was launched on August 3, 2004.
It made a fly-by of Earth in August 2005.
It made another fly-by of Venus in October 2006.
It made its first fly-by of Mercury happened on January 14, 2008, a second on October 6, 2008, and a third on September 29, 2009.