AcharyaChanakya/simple-wikipedia huggingface dataset:
The hosts of its opinion shows are Don Lemon, Chris Cuomo, Fredricka Whitfield, Erin Burnett, Brianna Keiler and Brooke Baldwin.
CNN has been criticized by the right-wing Media Research Center for having a left-wing bias. According to that same Center, it is less to the left than the news divisions of ABC, NBC, and CBS. It has been criticized by Arabs for having a pro-American bias.
A leader is somebody whom people follow. A leader has authority. For people to accept a leader, his or her leadership must therefore be legitimate.
Because people follow a leader, the leader can make people do things. A leader can therefore make people work together towards a common goal.
An example of a leader is the head of government of a country. People within the government "follow" the leader, and citizens look to the head of government for inspiration and guidance. Sometimes, when a head of government lacks legitimacy, people will stop following him or her. The head of government is therefore no longer able to lead properly. This may result in a new election, or in worst case civil war.
A group with no leader is called leaderless.
A blackboard, also called a chalkboard, is a surface on which chalk is visible. It is used as a surface to write on. It is usually made up of wood or fiber. It is painted black to reflect the white chalks. The high-grade blackboards are made of porcelain enamelled steel.
Blackboards are often used to help in teaching in school. Blackboards are not used as much now but can be seen in some schools still. The chalk dust got everywhere, and some people are allergic to chalk dust. Now people use whiteboards: they can take modern felt-tip colour markers.
Schoolteachers use the chalkboard to display things at large. It also makes the learning cooperative between teachers and student. Chalkboards can be black or dark green, in which case they may be called blackboards and greenboards.
Linux or GNU/Linux is a Unix-like operating system (or strictly family of) for computers. An operating system is a collection of the basic instructions that manage the electronic parts of the computer allowing running applications/programs. Linux kernel (the basis of the operating system) is free software, meaning everyone has the freedom to use it, see how it works, change it, or share it.
There is a lot of software for Linux and—like Linux itself—a lot of the software for Linux is free software. This is one reason why many people like to use Linux.
The defining component of Linux is the Linux kernel, an operating system kernel that Linus Torvalds developed, at first alone. Linux is typically packaged in a Linux distribution (or "distro" for short). Distributions also include supporting system software and libraries, many of which are provided by the GNU Project.
Popular Linux distributions include Debian, Fedora, and Ubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise Server. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions intended for servers may omit graphics altogether, and include a solution stack such as LAMP. Because Linux is freely redistributable, anyone may create a distribution for any purpose.
Linux was originally developed for personal computers. Linux is the leading operating system on servers such as mainframe computers, and the only O.S. used on supercomputers (at least on the TOP500 list, since November 2017). It is used by around 2.3% of desktop computers. The Chromebook, which runs the Linux kernel-based Chrome OS, dominates the US K–12 education market and represents nearly 20% of sub-$300 notebook sales in the U.S.
Linux also runs on embedded systems, which are devices whose operating system is typically built into the firmware and is highly tailored to the system; this includes mobile phones (especially smartphones), tablet computers, network routers, facility automation controls, televisions, digital video recorders, video game consoles and smartwatches. In fact, the Android operating system, a mobile operating system built on top of the Linux kernel, has the largest installed base of all general-purpose operating systems. In March 2017, it was reported that there were more users on Android than on Microsoft Windows, which is not based on Linux.
Linux is one of the most prominent examples of free and open-source software collaboration. The source code may be used, modified and distributed—commercially or non-commercially—by anyone under the terms of its respective licenses, such as the GNU General Public License.
In the 1980s, many people liked to use an operating system called Unix. But because it restricted the user from sharing and improving the system, some people made a new operating system that would work like Unix but which anybody could share or improve. MINIX, similar to Unix, was used as a teaching tool for university students to learn how operating systems worked. MINIX also restricted its sharing and improvement by its users.
A group of people called the GNU Project wrote different parts of a new operating system called G.N.U., but it did not have all the parts an operating system needs to work. In 1991 Linus Torvalds began to work on a replacement for MINIX that would be free to use, and which would not cost anything. Linus started the project when he was attending the University of Helsinki. This eventually became the Linux kernel.
Linus Torvalds shared the Linux kernel on some internet groups for MINIX users. Linus first called the operating system "Freax". The name Freax came from joining up the English words "free" and "freak", and adding an X to the name because Unix has an X in its name. Ari Lemmke, who worked with Linus at the University, was responsible for the servers that Freax was stored on. Ari did not think Freax was a good name, so he called the project "Linux" without asking Linus. Later, Linus agreed that Linux was a better name for his project.
Linux relied on software code from MINIX at first. But, with code from the G.N.U. system available for free, he decided it would be good for Linux if it could use that code, instead of code from MINIX, because MINIX did not let people share or change it how they wanted. The G.N.U. General Public License is a software license that lets people change any part of the code they want to, as long as they share any changes they make with the people they give their software to and allow them to redistribute it for free or for a price . The software from G.N.U. was all licensed under the G.N.U. General Public License, so Linus and the other people who worked on Linux could use it too.
To make the Linux kernel suitable for use with the code from the G.N.U. Project, Linus Torvalds started a switch from his original license (which did not allow people to sell it) to the G.N.U. GPL. Linux and G.N.U. developers worked together to integrate G.N.U. code with Linux to make a free operating system.
Since 1991, thousands of programmers and companies have worked to make Linux better including Google.
The mascot of Linux is a cartoon penguin named "Tux". When a person sees the penguin on software and hardware, it means that it will work with Linux, and sometimes all systems that are like Unix.
The idea of the penguin came from the creator of Linux, Linus Torvalds. The image was made by a man named Larry Ewing in a competition to create a logo. The image, Tux, did not win, but it was picked as a mascot later.
Tux has now become a symbol for Linux, and sometimes even for open source. He can be seen in many different places and often, when people refer to Linux, they often think about Tux. Tux has even been included in many video games, such as Super Tux (like Super Mario Bros.), Tux Racer (where players race Tux down an icy hill) and Pingus (like Lemmings).
Although there are only a few Linux versions for some Mac OS X and Microsoft Windows programs in areas like desktop publishing and professional audio and video there are programs that are comparatively similar in quality compared to those available for Mac and Windows.
Many free software programs that are popular on Windows, such as Pidgin, Mozilla Firefox, LibreOffice, Chromium, VLC and GIMP, are available for Linux. A growing amount of proprietary desktop software can also be used under Linux, such as Adobe Flash Player, Spotify and Skype. CrossOver is a proprietary solution based on the open source Wine project that supports running Windows applications such as Microsoft Office and Adobe Photoshop under Linux.
Linux has mainly been used as a server operating system, and has risen to be known by a lot of people in that area; Netcraft reported in February 2008 that five of the ten best internet hosting companies run Linux on their web servers. This is because of its stability and uptime, and the fact that desktop software with a graphical user interface for servers is often unneeded.
Linux is commonly used as an operating system for supercomputers. As of November 2017, all of the top 500 fastest supercomputers run Linux.
In 1992, Torvalds explained how he pronounces the word "Linux":
Torvalds has made available an audio sample which indicates his own pronunciation, in English and Swedish.
Some English speakers pronounce the name as lee-narks or lee-nix or lie-nix. According to Torvalds, that is incorrect pronunciation.
A 2001 study of Red Hat Linux 7.1 found this distribution had 30 million lines of code. The study showed that Red Hat 7.1 required about 8,000 years of time to develop. The study also said that if all this software had been made by proprietary means, it would have cost about $1.08 billion to make in the United States. As of March 7, 2011, Linux kernel would cost about $3 billion.
Version 3.10 of the Linux kernel, released in June 2013, has 15 million lines of code, while the version 4.1, released in June 2015, has grown to over 19.5 million lines of code by almost 14,000 programmers.
Most of the code (around 71%) was written in the C programming language, and many other languages were used, including C++, assembly language, Perl, Python, Fortran, and various shell scripting languages. A little more than half of all lines of code were licensed under the GPL.
People who want to get Linux can download it from a website on the internet or buy it from a store. Sometimes books and magazines about Linux have a CD. or DVD. with Linux on it. Any certain version of Linux is called a "distribution", or "distro". A Linux version has the Linux kernel, G.N.U. software, and some extra programs that might not be a part of G.N.U. Different versions include different extra programs. The versions used by the most people include:
People might pay some money for a version, so they can have a CD-ROM or DVD and to help the company to make their versions better. Usually when someone pays, it is so the company will help the user after they install it, which is called "support".
Software for Linux includes:
The Linux kernel and most GNU software are licensed under the GNU General Public License (GPL). The GPL requires that anyone who distributes the Linux kernel must make the source code (and any modifications) available to the recipient under the same terms. In 1997, Linus Torvalds said, "Making Linux GPL'd was definitely the best thing I ever did". Other key components of a Linux system may use other licenses; many libraries use the GNU Lesser General Public License (LGPL), a type of the GPL that is less restricted, and the X Window System uses the MIT License. "Linux" is a trademark of Linus Torvalds.
Open source is a software similar to free software, but is more related to business. It is different from other software because the source code is available to everyone. The source code is a set of instructions for the computer, written in a programming language.
Anyone can see how the source code works and can change it if they want to make it work differently. The opposite of open source is closed source. Closed source software is not available to everyone. Open source has a lot in common with free software but each has its own focus and goals.
Open source and free software have been around for decades. They became more popular with the Linux and BSD software communities. To protect the code, a special user license is used. The most common kinds of licence are the GPL, BSD and LGPL. Wikipedia uses open source too. The Open Source Movement is led by the Open Source Initiative.
The open source movement became separate from the free software movement in 1998.
Desktop environment
In graphical user interfaces and consoles a desktop environment is a location on a personal computer that helps the user get around on the computer. The desktop itself is a place in the operating system used for short cuts to computer files and folders on the hard drive. Computer icons (small pictures) are used to represent files/folders. Clicking these icons will open or start a folder or program. The desktop is the area where the start menu is if the computer has a start menu.
Usually the desktop is the main screen on the computer. If no programs or folders are open, the computer will display the desktop.
The most common desktop environment on personal computers is the one given by Microsoft Windows; another common environment is the one given by Apple Mac OS X. Other mostly-used desktop environments for Unix-like operating systems using the X Window System are KDE, GNOME, Xfce. There are also other desktop environments, including : Aston, EDE, GEM, IRIX Interactive Desktop, Sun's Java Desktop System, Mezzo, Project Looking Glass, ROX Desktop, UDE, Xito, XFast.
Apache OpenOffice (formerly OpenOffice.org) is a free open source office suite. The free software project was formerly hosted by Sun Microsystems and then Oracle Corporation and is currently hosted by Apache. It is available for many different operating systems, including Microsoft Windows, Linux, OS X, FreeBSD and Solaris; and is meant to be an alternative to Microsoft Office. It supports Microsoft Office file formats as well as its own OpenDocument format.
The ".org" part of the previous name OpenOffice.org is there because OpenOffice is already trademarked. It is often called "OOo" for short.
OpenOffice is based on the older StarOffice software that was created by Sun Microsystems.
OpenOffice is a collection of applications that work together closely to provide the features expected from a modern office suite. Many of the parts are designed to be alternatives to those available in Microsoft Office. The parts available include:
Download means getting information from another computer or server. The opposite of downloading is uploading, which is sending data to another computer. Usually we do not say "download" for a single web page (for example when you open this page on your computer). When we say we downloaded something, it is normally a bigger computer file, like data or a computer program.
The word downloadable means the ability to get information or data from an owner for one's use. The source is expected to be authentic and have the right to send it. At the user's end, the downloaded information or data are to be used based on agreement notice.
In the 21 century, it is very easy to download files or informations - legally or not - from the internet.
As most non-technical users use the word download to talk about any data transfer, the word "sideload" is sometimes used for local to local transfers as distinct from distant ones.
GNOME is a computer desktop environment. It was designed for Linux, but many other operating systems can use it too. GNOME aims to provide an easy way to use a computer. GNOME is a free software project. It was made because people were questioning whether KDE is free. GNOME is part of the GNU project.
According to the GNOME website:
The GNOME project puts heavy emphasis on simplicity, usability, and making things “just work” (see "KISS principle"). The other aims of the project are:
GNOME has many applications written for it. Some of them include:
Dogs ("Canis lupus familiaris") are domesticated mammals, not natural wild animals. They were originally bred from wolves. They have been bred by humans for a long time, and were the first animals ever to be domesticated. There are different studies that suggest that this happened between 15.000 and 100.000 years before our time. The dingo is also a dog, but many dingos have become wild animals again and live independently of humans in the range where they occur (parts of Australia).
Today, some dogs are used as pets, others are used to help humans do their work. They are a popular pet because they are usually playful, friendly, loyal and listen to humans. Thirty million dogs in the United States are registered as pets. Dogs eat both meat and vegetables, often mixed together and sold in stores as dog food. Dogs often have jobs, including as police dogs, army dogs, assistance dogs, fire dogs, messenger dogs, hunting dogs, herding dogs, or rescue dogs.
They are sometimes called "canines" from the Latin word for dog - "canis". Sometimes people also use "dog" to describe other canids, such as wolves. A baby dog is called a pup or puppy. A dog is called a puppy until it is about one year old.
Dogs are sometimes referred to as "man's best friend" because they are kept as domestic pets and are usually loyal and like being around humans. Dogs like to be petted, but only when they can first see the petter's hand before petting; one should never pet a dog from behind.
August 26 is National Dog Day. While March 26 is National Puppy Day.
Dogs have four legs and make a "bark," "woof," or "arf" sound. Dogs often chase cats, and most dogs will fetch a ball or stick.
Dogs can smell and hear better than humans, but cannot see well in color because they are color blind. Due to the anatomy of the eye, dogs can see better in dim light than humans. They also have a wider field of vision.
Like wolves, wild dogs travel in groups called packs. Packs of dogs are ordered by rank, and dogs with low rank will submit to other dogs with higher rank. The highest ranked dog is called the alpha male. A dog in a group helps and cares for others. Domesticated dogs often view their owner as the alpha male.
Different dog breeds have different lifespans. In general, smaller dogs live longer than bigger ones. The size and the breed of the dog change how long the dog lives, on average. Breeds such as the Dachshund usually live for fifteen years, Chihuahuas can reach age twenty. The Great Dane, on the other hand has an average lifespan of six to eight years; some Great Danes have lived for ten years.
All dogs are descended from wolves, by domestication and artificial selection. This is known because DNA genome analysis has been done to discover this. They have been bred by humans. The earliest known fossil of a domestic dog is from 31,700 years ago in Belgium. Dogs have lived with people for at least 30,000 years. In 2013, a study was published that showed that the skull and teeth of a canid, dated to 33,000 years ago, had characteristics closer to a dog than to a wolf, and the authors conclude that "this specimen may represent a dog in the very early stages of domestication, i.e. an “incipient” dog." The researchers go on to suggest that it was, however, a line that did not lead to modern dogs. Genetically, this material is closer to that of a modern dog than to that of a wolf. Other signs of domestication are that sometimes, dogs were buried together with humans. Evidence of this is a tomb in Bonn, where a man of about 50 years of age, a woman of about 25 years of age, the remains of a dog, plus other artifacts were found. Radiocarbon dating showed that the human bones were between 13.300 and 14.000 years old.
Dogs are often called "man's best friend" because they fit in with human life. Man refers to humankind and not just guys (Old English). Dogs can serve people in many ways. For example, there are guard dogs, hunting dogs, herding dogs, guide dogs for blind people, and police dogs. There are also dogs that are trained to smell for diseases in the human body or to find bombs or illegal drugs. These dogs sometimes help police in airports or other areas. Sniffer dogs (usually beagles) are sometimes trained for this job. Dogs have even been sent by Russians into outer space, a few years before any human being. The first dog sent up was named Laika, but she died within a few hours.
There are at least 800 breeds (kinds) of dogs. Dogs whose parents were the same breed will also be that breed: these dogs are called purebred or pure pedigree dogs. Dogs with parents from different breeds no longer belong to one breed: they are called "mutts", "mixed-breed dogs", "hybrids", or "mongrels". Some of the most popular breeds are sheepdogs, collies, poodles and retrievers. It is becoming popular to breed together two different breeds of dogs and call the new dog's breed a name that is a mixture of the parents' breeds' two names. A puppy with a poodle and a pomeranian as parents might be called a Pomapoo. These kinds of dogs, instead of being called mutts, are known as designer dog breeds. These dogs are normally used for prize shows and designer shows.
They can be guide dogs.
Blindness is to not see anything. Some people are called blind, even though they can see a little bit. This is because they cannot see clearly, but only see unfocused shapes or colors.
In modern countries, few young people are blind. In all the world, blindness is mostly caused by malnutrition and diseases of old people, like cataracts and trachoma. People can become blind because of diseases or accidents, but sometimes people are born blind.
Some people are "color blind", which means they can see, but cannot tell certain colors apart.
When people are blind they use such things as the alphabet in "braille" and "guide dogs" to do every day life things.
Famous blind people have included Louis Braille, the inventor of the braille alphabet, Stevie Wonder, Ray Charles and Helen Keller.
The Arctic is the area around the Earth's North Pole. The Arctic includes parts of Russia, Alaska, Canada, Greenland, Lapland and Svalbard as well as the Arctic Ocean. It is an ocean, mostly covered with ice. Most scientists call the area north of the treeline Arctic. Trees will not grow when the temperatures get too cold. The forests of the continents stop when they get too far north or too high up a mountain. (Higher places are colder, too.) The place where in the trees stop is called the tree line.
The area north of the treeline is not an empty ice field. In fact, the only large ice-covered land is central Greenland, which is covered year-round by a continental glacier. The land of the Arctic is around the edges of the Arctic Circle and is usually covered with tundra. A tundra is a cold, almost treeless plain covered with moss and grasslike plants called "sedges".
Tundras do not get very much rain or snow. However, they are very wet in the summer time because, three feet (1m) or so below the surface, the ground is always frozen. This permafrost is a layer of ice with the hardness of stone that keeps water from soaking into the earth beneath it. Permafrost can be thousands of feet thick. In the summer the ground on top thaws out when the sun shines and the snow that did fall melts. But the melted snow cannot drain into the ground; it just soaks the topsoil. There is no place for the water to go, except to form lakes and puddles on top of the ground until it freezes again or dries up.
In the Arctic, during summer there are nights when the Sun never sets. This is because during summer there, the North Pole points toward the Sun. So, sometimes people call it the Land of the Midnight Sun.
The word comes from the Greek word "αρκτος", meaning "bear". The North Pole aims at the stars called the Great Bear and the Little Bear. This is why it is called the Arctic.
In some parts of the Arctic the ground is covered with bright-colored flowers during the short summer. These little plants have very short stems. They must stay close to the ground, because the earth is warmer than the biting winds that blow above it. Even some rocks have plants growing on them. These rock plants are called lichens. Lichens will grow on the bare rocks. Yellow reindeer moss is really a lichen. It grows slowly, but often grows over six inches (15 cm) tall. It is spongy and full of water. This plant is the summer food for reindeer.
Trees are rare on the tundra. Only in the protected valleys or along the riverbanks are small trees able to grow. Rivers come into the Arctic from the warmer south. The places along their banks are a little bit warmer than the rest of the tundra, and trees can grow there. Otherwise only a few clusters of bushes grow sparingly. Berries are the only fruit that grows in the Arctic.
Each summer the ice and snow melt, allowing the animals to find food and the plants to flower. The moisture from the snow stays toward the top of the ground's surface. Plant roots can use it for their growth. Even so, in many places the soil is too poor for plant's growth. Less than half of the tundra has plants growing on it.
The polar bear is the world's largest meat-eating land animal. Polar bears are well adapted to hunt seals out on the ice. They are excellent swimmers, and the coldest water does not bother them. They wait by breathing holes if they pick up the scent of a seal. They can also break through the ice at thin areas. Sometimes they can sneak up on a sleeping seal. They have a very strong sense of smell, which they use to find prey out on the ice. Polar bears get most of their food when there is pack ice. They must eat and store fat before the ice is gone: they cannot catch seals in open water. After mating, females dig themselves into a den of snow on land for the rest of the winter. There, they have their cubs, usually twins. Bears usually eat fish, birds' eggs, seaweed, and dead whales, but they would rather have a meal of seal or walrus.
The Arctic fox often trails the bears onto the ice to eat their leftover food. The fox also eats rabbits, lemmings, and voles.
The lemmings and voles are the rats and mice of the Arctic. The lemmings have very short tails. They live underground in summer. Because the top soil freezes in the winter, they cannot burrow underground then, so they live under the snow during the colder months. They eat plants and roots. In a year with plenty of food, millions of lemmings will be roaming the tundra. The owls and foxes have more food than they can eat. They will have more young in years when there are many lemmings. However, the tundra does not have enough food for millions of lemmings. They rush across the tundra looking for food, and are eaten by predators or starve to death. Some try to swim across lakes or rivers and drown. The few that remain continue to have families.
Caribou and their relative, the reindeer, also live in the Arctic. The caribou are now found mostly in North America, and they are larger than the reindeer. Large herds feed on the grass and lichens. When fall comes, they move south to winter feeding grounds. They dig through the snow with their sharp hoofs for food. Their hollow fur creates a cushion of air around them that helps them to stay warm. In the spring they return north to the summer pastures, where their calves are born. An hour or so after being born, the calves are able to follow the herd toward the Arctic Ocean. Most of the world's reindeer live in Europe and Asia. Some of these reindeer are not wild. They have been tamed by herdsmen who protect them from wolves and lead the migrations each spring and fall. Also, the musk ox, which looks like a shaggy buffalo, lives in the Arctic.
In summer, many birds visit the Arctic, and most of them are water birds, such as geese, ducks, swans, loons, and Arctic terns. Flying in for the summer, they raise their young and return south for the winter. The snowy owl and the ptarmigan stay all year. The color of the snowy owl matches the snow. The ptarmigan's summer plumage changes to white when it gets colder.
The smallest animals of the Arctic are the flies and the mosquitoes. Thick swarms bite both men and animals in the summer. The reindeer try to escape the mosquitoes by running to higher pastures, but the only real help comes with the snow and cold, when the swarms die off for another season.
One of the surprises of the Arctic is that many people live there. Some people have lived there for thousands of years. Eskimo and Lapp people lived in the Arctic long before electric heaters, snow-mobiles, and modern houses.
In an extremely northern part of Europe there is a place called Lapland. It is not a country, but parts of four countries. The people who lived there are called Lapps by outsiders. They call themselves "Sami". The Lapps of these four countries lived there long before the countries of Northway, Sweden, Finland, and Russia were created. There were several kinds of Lapp people. Some lived by the ocean and lived mostly on fish. Another group lived along the warmer rivers. These people did a little farming, hunting, and fishing to live.
But the best known of the Lapp people were the nomads who raised reindeer. The Lapps survived in their harsh homeland by domesticating the reindeer. The Lapps were able to get everything they needed from the deer. They ate mostly meat, milk, and cheese. Their clothes were made froom reindeer skins and wool. Their tents were also made from deer skins. They are known for the beautifully decorated woolen clothing they made.
The Lapps protected the herds, moving with them as they migrated from summer to winter pastures. They used trained reindeer to pull sleds carrying their supplies. During the winter, the herds moved south of the treeline. The Lapps would live nearby in homes made of logs or sod. The Lapps were very careful not to waste anything they got from the reindeer. Milk was taken from the reindeer to drink or make cheese. Meat was taken for food. The blood was frozen in chunks and used for soup and pancakes. Knives and belt buckles were carved from the bones and antlers. The sinews were used as sewing thread. Cleaned-out stomachs were used to carry milk or cheese. Every part of a dead reindeer was used.
Winter clothing was made from layers of deer skin. The inside layer would be worn with the fur facing in toward the person's skin. The second layer was worn with the fur facing out. Boots were also made of fur, lined with grass that had been gathered during the short summer. Every evening the grass would be taken out and dried by the fire, so it would be ready to use again the next day. Thus, a Lapp could be warm and comfortable in even the coldest weather.
Today only a few of the Lapp people still follow the herds. Those few use modern tools on their ancient migration. They use snowmobiles to herd the reindeer and rifles to kill the wolves that chase them. Even helicopters and radios are used to locate and move the reindeer. Most of the Lapp people now live on small farms in one of the four nations of Lapland. They raise crops and animals, including a few reindeer, to meet their needs. The sale of reindeer meat is an important source of income for the Lapp people.
Eskimos are Arctic people, too. They sometimes ate raw meat. Eskimos were also nomads, but they did not have any animals except for dogs, which they used for pulling their sleds and helping them hunt. They were hunters and gatherers, and they lived off on whatever they found or killed. Like the Lapps, though, they were very careful to make good use of every part of the animals they killed. Eskimos lived in tents during the summer, and sod houses or igloos in the winter. The Eskimos made very clever things from the bones, antlers, and wood they had. They built different kinds of boats.
Eskimos did not have a government or laws, because they learned early in life to help each other in order to survive. Always sharing food, they usually moved around in small groups looking for food. Sometimes they'd get together in a large group when they hunted big animals such as whales. The men did the hunting and building the homes, and the women cooked, made the clothes, and took care of the children.
The Arctic region has many minerals that are important to people. Iron, lead, coal, copper, gold, and tin are all mined in different parts of this cold land. Large amounts of petroleum have been discovered in the Arctic in Russia, Alaska, and Canada. People live and work in the Arctic to remove these valuable minerals and sell them.
The oil in Alaska, for example, is very important to the United States. The main source is the Prudhoe Bay Oil Field on Alaska's north coast. It was discovered in 1968. Plans were quickly made to build a pipeline to bring the oil to an ice-free port so it could be shipped south. Oil companies spent billions of dollars to build the Trans-Alaska Pipeline in the mid-1970s. It had to be built above the ground in the northern section because of the permafrost. The warm oil in the pipes could have melted the permafrost and caused the ground to sink. That would have broken the pipes and caused an oil spill. The pipeline was completed in 1977. It brings oil to the seaport of Valdez on Alaska's south coast. From there the oil is taken by huge tankers to refineries along the west coast of the United States. If you live in western America, your family car may have Alaskan gasoline in its tank.
Russia has more land in the Arctic than any other nation. The Russian Arctic in Asia and the area just south of it are called Siberia. It is such an empty, harsh place that it has been used as a penal colony for many years. The old Russian rulers and the modern communist Soviets would send criminals and people who disagreed to the government to live there. However, many people were also sent there to remove minerals, harvest trees from forests, and build cities.
Russia has a huge port city right in Lapland, within the Arctic Circle. Murmansk is the largest city north of the Arctic Circle. The port is kept ice-free by the warm waters of the Gulf Stream coming up around Norway and Sweden from the South Atlantic. Huge icebreakers work to keep a path open so ships can reach the port. The port ships out fish, minerals, and lumber to Russia and the rest of the world.
The Arctic is also the shortest way (Great circle route) for airlines to fly between some cities on different continents. The flight from London to Tokyo, for example, is 1,400 miles shorter if flown across the top of the world instead of the old route south across Europe and Asia. The polar route from San Francisco to Norway is several hours shorter than the same flight going across the United States and the Pacific Ocean.
Thus, man is making use of the Arctic in various ways even though it is a hard place to live.
A sin is a bad act. Particularly, it is a bad act against another person(s), an animal, a spirit, or a god.
In Abrahamic religions, such as Christianity and Judaism, it is an act that goes against what God wants. It turns people away from God and true happiness. In Exodus chapter 20, Moses was given the Ten Commandments by God, explaining important sins like murder and idolatry. This is not believed by all people, and not all societies have the same idea of sin.
There is a difference between sins and prohibitions. For example, Muslims and Jews say that it is wrong to eat pork, and Hindus do not eat beef. That is for them, but for others it is not wrong to eat these things.
Summer is one of the four seasons. It is the hottest season of the year. In some places, summer is the wettest season (with the most rain), and in other places, it is a dry season. Four seasons are found in areas which are not too hot or too cold. Summer happens to the north and south sides of the Earth at opposite times of the year. In the north part of the world, summer takes place between the months of June and September, and in the south part of the world, it takes place between December and March. This is because when the north part of the Earth points towards the Sun, the south part points away.
Many people in rich countries travel in summer, to seaside resorts, beaches, camps or picnics. In some countries, they celebrate things in the summer as well as enjoying cool drinks. Other countries get snow in the summer just like winter.
Summer is usually known as the hottest season
A month is an amount of time used with calendars. It is about 1/12th of a year. It is a little longer than a natural synodic orbital period of the moon, ca. 29.5 days. Lunar calendars use the natural synodic month. For some purposes astronomers use the sidereal month of 27.3 days.
Other calendars, called "solar calendars", ignore the moon, and depend entirely on the Sun — for example, the Gregorian calendar of 365 or 366 days (12 months) used in much of the world today.
Alberta is a province in western Canada. It is bounded by the provinces of British Columbia on the west, Saskatchewan on the east, the US state of Montana on the south and the Northwest Territories to the North.
Alberta is the fourth largest Canadian province with an area of . Alberta has around 4,067,175 living there, making it the fourth most populous province in Canada.
The capital of Alberta is Edmonton lying near the middle of Alberta. The city of Calgary, Alberta’s other major centre is located about 300 kilometres to the south of Edmonton.
Canada became a country in 1867. It was much smaller than it is now, and did not include the parts of the country to the west. From 1670 to 1870, parts of Alberta were included in "Rupert's Land," land owned by the Hudson’s Bay Company in support of it’s trading monopoly over a vast area of Canada and parts of the United States. Northern part of Alberta was part of the what was then called "Northwestern Territories."
Alberta was made a province of Canada in 1905, at the same time as Saskatchewan.
The Aboriginal peoples of Canada are referred to as First Nations or by the Name of their Nation. Mixed (European/Aboriginal) People are called Metis.
Alberta is very cold in the winter and has a lot of snow during the very cold season. There is a dry part of Alberta in the south.
Alberta has a huge amount of oil (in the Athabasca Oil Sands) and natural gas.
There are also a lot of farms in Alberta. Farmers grow several different types of crops Farmers mainly grow wheat. There are also a lot of cows on Alberta farms, and Alberta beef is exported.
There is diesel fuel in Alberta.
Electronics is the study of electricity (the flow of electrons) and how to use that to build things like computers. It uses circuits that are made with parts called components and connecting wires to do useful things. The science behind Electronics comes from the study of physics and gets applied in real-life ways through the field of electrical engineering.
Many people can name several simple electronic components, such as transistors, fuses, circuit breakers, batteries, motors, transformers, LEDs and bulbs, but as the number of components starts to increase, it often helps to think in terms of smaller systems or blocks, which can be connected together to do something useful.
One way of looking at an electronic system is to separate it into three parts:
A television set, for example, has as its input a broadcast signal received from an antenna, or for cable television, a cable.
Signal processing circuits inside the television set use the brightness, colour, and sound information contained in the received signal to control the television set's output devices. The display output device may be a cathode ray tube (CRT) or a plasma or liquid crystal display screen. The audio output device might be a magnetically driven audio speaker. The display output devices convert the signal processing circuits' brightness and colour information into the visible image displayed on a screen. The audio output device converts the processed sound information into sounds that can be heard by listeners.
Analysis of a circuit/network involves knowing the input and the signal processing circuit, and finding out the output. Knowing the input and output and finding out or designing the signal processing part is called "synthesis".
People started experimenting with electricity as early as 600 B.C.E, when Thales of Miletus discovered rubbing fur on amber would cause them to attract each other.
Starting in the 1900s, devices used glass or metal vacuum tubes to control the flow of electricity. With these components a low power voltage can be used to change another. This revolutionized radio, and allowed other inventions.
In the 1960s and early 1970s transistors and semiconductor began replacing vacuum tubes. Transistors can be made much smaller than vacuum tubes and they can work using less energy.
At about the same time, integrated circuits (circuits that are integrated inside other circuits) became commonly used. Integrated circuits made it possible to reduce the number of parts needed to make electronic products and made the products much cheaper in general.
Analog circuits are used for signals that have a range of amplitudes. In general, analog circuits measure or control the amplitude of signals. In the early days of electronics, all electronic devices used analog circuits. The frequency of the analog circuit is often measured or controlled in analog signal processing. Even though more digital circuits are made, analog circuits will always be necessary, since the world and its people work in analog ways.
Pulse circuits are used for signals that require rapid pulses of energy. For example, radar works by using pulse circuits to create and send high powered bursts of radio energy from radar transmitters. Radar antennas are used to send ("transmit") the high powered bursts in the direction the antenna is pointed.
The radar transmitter's pulses or bursts of radio energy hit and bounce back (they are "reflected") from hard and metallic objects. Hard objects are things like buildings, hills, and mountains. Big things made of metal include aircraft, bridges, or even objects in space, like satellites. The reflected radar energy is detected by radar pulse receivers which use both pulse and digital circuits together. The pulse and digital circuits in radar pulse receivers are used to show the location and distance of objects which have reflected the radar transmitter's high powered pulses.
By controlling how often the rapid pulses of radar energy are sent out by a radar transmitter (called the transmitter's "pulse timing"), and how long it takes for the reflected pulse energy to come back to the radar receiver, one can tell not only where objects are, but also how far away they are. Digital circuits in a radar receiver calculate the distance to an object by knowing the time interval between energy pulses. The radar receiver's digital circuits count how long it takes between pulses for an object's reflected energy to be detected by the radar receiver. Since radar pulses are sent and received at approximately the speed of light, the distance to an object can easily be calculated. This is done in digital circuits by multiplying the speed of light by the time it takes to receive the radar energy reflected back from an object.
The time between pulses (often called "pulse rate time", or PRT) sets the limit on how far away an object can be detected. That distance is called the "range" of a radar transmitter and receiver. Radar transmitters and receivers use long PRT's to find the distance to objects that are far away. Long PRT's makes it possible to accurately determine the distance to the moon, for example. Fast PRT's are used to detect objects that are much closer, like ships at sea, high flying aircraft, or to determine the speed of fast moving automobiles on highways.
Digital circuits are used for signals that only turn on and off instead of often working at levels somewhere between on and off. Active components in digital circuits typically have one signal level when turned on, and another signal level when turned off. In general, in digital circuits a component is only switched on and off.
Computers and electronic clocks are examples of electronic devices that are made up of mostly digital circuits.
Basic blocks:
Complex devices:
Scalars are simple numbers. They are used for measuring things. Many things can be measured, and the measure can be explained by only giving the number.
Suppose we are measuring a rod. We could give the measured length as 2 metres or 3 cm—depending on the length of the rod under observation. Here, only the figure 2 or 3 along with the unit of measure is enough to transmit information about the rod.
Other examples of scalars are:
In other words, mass is measured by scalars, just like distances are measured by scalars.
In mathematics, scalars are distinguished from more complex mathematical objects such as vectors and matrices in that they consist of only one number. A scalar formula_1 can also be multiplied to a vector formula_2 or a matrix formula_3, resulting in the vector formula_4 and the matrix formula_5, respectively. For vectors, scalar multiplication produces a new vector of different length in the same or opposite direction of the original vector.
Photons (from Greek φως, meaning "light"), in many atomic models in physics, are particles which transmit light. In other words, light is carried over space by photons. Photon is an elementary particle that is its own antiparticle. In quantum mechanics each photon has a characteristic quantum of energy that depends on frequency: A photon associated with light at a higher frequency will have more energy (and be associated with light at a shorter wavelength).
Photons have a rest mass of 0 (zero). However, Einstein's theory of relativity says that they do have a certain amount of momentum. Before the photon got its name, Einstein revived the proposal that light is separate pieces of energy (particles). These particles came to be known as photons.
A photon is usually given the symbol γ (gamma),
Photons are fundamental particles. Although they can be created and destroyed, their lifetime is infinite.
In a vacuum, all photons move at the speed of light, c, which is equal to 299,792,458 meters (approximately 300,000 kilometers) per second.
A photon has a given frequency, which determines its color. Radio technology makes great use of frequency. Beyond the visible range, frequency is less discussed, for example it is little used in distinguishing between X-Ray photons and infrared. Frequency is equivalent to the quantum energy of the photon, as related by the Planck constant equation,
where formula_2 is the photon's energy, formula_3 is the Plank constant, and formula_4 is the frequency of the light associated with the photon. This frequency, formula_4, is typically measured in cycles per second, or equivalently, in Hz. The quantum energy of different photons is often used in cameras, and other machines that use visible and higher than visible radiation. This because these photons are energetic enough to ionize atoms.
Another property of a photon is its wavelength. The frequency formula_4, wavelength , and speed of light formula_7 are related by the equation,
where formula_9 (lambda) is the wavelength, or length of the wave (typically measured in meters.)
Another important property of a photon is its polarity. If you saw a giant photon coming straight at you, it could appear as a swath whipping vertically, horizontally, or somewhere in between. Polarized sunglasses stop photons swinging up and down from passing. This is how they reduce glare as light bouncing off of surfaces tend to fly that way. Liquid crystal displays also use polarity to control which light passes through. Some animals can see light polarization.
Finally, a photon has a property called spin. Spin is related to light's circular polarization.
Light is often created or absorbed when an electron gains or loses energy. This energy can be in the form of heat, kinetic energy, or other form. For example, an incandescent light bulb uses heat. The increase of energy can push an electron up one level in a shell called a "valence". This makes it unstable, and like everything, it wants to be in the lowest energy state. (If being in the lowest energy state is confusing, pick up a pencil and drop it. Once on the ground, the pencil will be in a lower energy state). When the electron drops back down to a lower energy state, it needs to release the energy that hit it, and it must obey the conservation of energy (energy can neither be created nor destroyed). Electrons release this energy as photons, and at higher intensities, this photon can be seen as visible light.