AcharyaChanakya/simple-wikipedia huggingface dataset:
Politics is the way people choose the leaders of their communities and the things they decide are important enough to do. Hamiltonians like choosing socially minded people to governm themselves, especially women and minorities. Many people who were mayors, members of Provincial Parliament (MPPs) or members of Parliament (MPs) have things named for them in the city, such as:
Netural and Mohawk Native Canadians of the Six Nations were the first people to live in this area. In 1616, Étienne Brûlé probably became the first European to visit what is now Hamilton. United Empire Loyalists moved into the Hamilton area during and after the American Revolution. The Battle of Stoney Creek was fought during the War of 1812 in what is now Hamilton.
In the mid- to late 1800s, Hamilton became an industrial city with lots of factories . It was close to limestone from the Niagara Escarpment, coal from the United States, iron ore mined from northern Ontario. But factories demanded that people work hard jobs for long hours. In 1872, Hamilton workers marched for a work day of no more than nine hours! The two large steel factories were Stelco (the Steel Company of Canada), created in 1910 and the Dofasco (Dominion Steel Casting Company) in 1912. Dominion is an old word often heard to describe Canada when it was part of the British Empire.
Many schools were built between 1910 and 1930, including Adelaide Hoodless School, Memorial School (for the First World War, Viscount Allenby School (WWI general) and Earl Kitchener School (WWI general). The First World War is often shortened to WWI.
In the 1930s, the Great Depression hit Hamilton. People were unemployed and poor. Factories stoped running. Times were hard. Then the Second World War started and people got jobs again in the army and building guns for the army. August 19, 1942, hundreds of young men from Hamilton were killed by the German army when they tried to attack Dieppe in France.
There are a few professional sports in Hamilton. The Tiger-Cats of the Canadian Football League play at Ivor Wynne Stadium. Hamilton would like a National Hockey League team but it does not have one. The Hamilton Bulldogs of the Ontario Hockey League play at Copps Coliseum.
There are many amateur sports in Hamilton. People of all ages can run in the Around the Bay Race . It takes 30 km to go around the edge of Hamilton Harbour or Burlington Bay. "The Hamilton Spectator" also hosts amateur indoor games. Every year, children from Hamilton and Flint, Michigan compete in the Canusa Games.
The Commonwealth Games are like the Olympics for people who used to be ruled by Britain. In 1930, Hamilton became the first ever host for what ere then called the Empire Games. The city also tried to host the 2010 Commonwealth Games.
McMaster University and Mohawk College have produced national championship teams in a number of sports. McMaster University is a perennial powerhouse in Men's Basketball and Football.
Here in Hamilton we also have recreational leagues for kids to enjoy their childhood by playing many recreational sports such as Hockey(Stoney Creek Minor Hockey), Soccer(Stoney Creek Soccer Club), and Football with (Steelcity Ironmen). In addition, there are a number of other community sport clubs like the Mt Hamilton Youth Soccer Club which has provided an avenue for children to play soccer since 1964.
There are many buses, apart from the school buses operated by the Hamilton-Wentworth District School Board. For $2.55, the Hamilton Street Railway or HSR takes people inside and across the city.
Travellers can also get to places like Niagara Falls, Dunnville, Buffalo, Kitchener, and London. These buses are run by companies called Greyhound, Trentway Wagar and McCoy. GO Transit has buses and trains that go to Toronto. Using GO however is not a part of the HSR.
The city streets in the old city of Hamilton follow a pattern. The big streets going north and south are in straight lines. When they are on the Mountain, they have "Upper" in front the their names, except for Garth Street which should be Upper Dundurn Street.
Streets are called "North," such as "James Street North," if they are north of King Street or Queenston Road. Streets are called "South" if they are south of King or Queenston. Streets are called "East," such as "East 5th Street" or "Main Street East," if they are east of James Street or Upper James Street. Streets are called "West" if they are west of James or Upper James.
King and Main Streets are major roads that are almost parallel or side by side one another. They cross at the Delta in east Hamilton. For most of King and Main, cars could only travel one way. So instead of thinking of them as two streets, think of them as one street with a very wide boulevard between them. This changed in the early 2000s, and most of the streets in Downtown Hamilton are now two-way.
Throughout the city there are some neighbourhoods with weird or strange street names. For example, Birdland has streets named after birds like Cardinal, Blue Jay and Swallow. Another neighbourhood on the Mountain has streets named after people from the French Revolution, such as Napoleon, Josephine, and Robespierre. Riverdale West, in the Lower City, has streets named after types of berries.
A shape is a geometric figure that can be described with mathematics. One way to classify shapes is to describe a bigger kind of shape that the shape is one of. For example, they can be classified by their different numbers of dimensions. Thus, circles are two-dimensional shapes so, like other 2D shapes, they will fit into a flat plane.
Three-dimensional objects like cubes will not fit inside a plane, because they are not flat. Four-dimensional shapes made of polygons are called polychorons, and shapes made of polygons of any dimension are polytopes.
Two shapes are said to be equal, if one can be changed into the other by turning, moving, growing, shrinking, or more than one of these in combination. Geometry is one of the practical sections of mathematics which involves various shapes and sizes of different figures and their properties.
These are two-dimensional shapes or flat plane geometry shapes. Their sides are made of straight or curved lines. They can have any number of sides. Plane figures made of lines are called polygons. Triangles and squares are examples of polygons.
These are three-dimensional shapes. Their sides are made of flat or curved surfaces.
Quechua
Quechua, sometimes written Quichua or Ketchua, is a language spoken by 8 million people in the South American nations of Peru, Bolivia, Ecuador, Argentina and Colombia. It was also the language of the ancient Inca Empire. It's part of the Quechuan languages family.
It is the most-spoken Native American language in South America. It is also the most widely-spoken indigenous language. A quarter of people in Peru speak Quechua. People who speak Quechua as their first language are called Quechua Indians by Spanish-speakers. However, the Quechua refer to themselves as "Runa" ("the people") and call their language "Runa Simi".
Quechua has only three vowel sounds: "a", "i", and "u".
Quechua has given names to many places in Peru, including the Ancash Region. "" is the Quechua word for "blue", and it is thought that the name refers to the region's blue skies.
Drinking water, also known as potable water, is water that is safe to drink or to use for food preparation.
Water in rivers, stream, lakes and underground may contain organisms that cause disease. It may also contain chemicals that might cause illness.
'Water treatment' involves filtering the water through sand beds and then adding a chemical to kill any remaining organisms.
The amount of drinking water needed for good health varies. Americans, on average, drink one litre of water per day and 95% drink less than three litres per day. For those who work in a hot climate, up to 16 litres a day may be required. Liquid water is essential for life.
In developed countries, tap water meets drinking water quality standards. Other uses include washing, toilets, and irrigation. Greywater (wastewater) may be used for toilets or irrigation. Using greywater for irrigation may have risks. Water may be unacceptable if it has high levels of toxins or suspended solids.
A pen (Latin: "pinna", feather) is a tool used for writing or drawing. The ink of the pen is pressed onto paper and dries very fast.
"Reed pens" are the oldest known type of pen. They were made from reeds growing in the delta of the Nile. The ancient Egyptians invented them, and also invented black ink, using soot and gum arabic. Their pens had split nibs to regulated the flow of ink to the writing tip. This simple design is still used in calligraphy today.
"Quill pens" are one of the oldest type of pens. A quill pen is the feather of a bird, usually a goose. The end of the feather (the quill) was kept very sharp and had to be dipped into ink after every few words.
Reed and quill pens are "dip pens" because they have to be dipped in ink many times during writing or drawing. Modern dip pens have nibs made of metal.
"Fountain pens" are like dip pens, but can hold enough ink inside to write several pages before being refilled. Inside, the ink is held in a sac or cartridge.
A "ballpoint pen" is generally cylindrical plastic shaft that holds ink and is smaller than a fountain pen. It has a small hard ball on the writing end that rolls the ink onto the paper.
A "stylus" is a pen that cannot write on paper, but can write on clay or wax. Styli of wood or metal have been used for thousands of years, for example in cuneiform writing. A modern computer stylus is usually made of plastic and may have electronics inside. It is used with a touchscreen.
The coming of the personal computer much reduced the need to write on paper. All the same, a personally written letter suggests "I think so much of you that I took the effort to write a "real" letter."
Leet (sometimes written as "1337" or "l33t"), also known as eleet or leet-speak, is another alphabet for the English language that is used mostly on the internet. It uses various combinations of ASCII characters to replace Latinate letters. For example, leet spellings of the word "leet" include "1337" and "l33t"; "eleet" may be spelled "31337" or "3l33t". It is used on the internet in forums, chat rooms and online games.
Leet is mostly used for English, but can also be used with other languages including French, Spanish and German.
Leet-speak is a mixture of words (mostly computer-related jargon) spelled incorrectly intentionally*, usually coming from typographical errors (e.g. "the" becomes "t3h"). The words of Leet-speak are usually put together to create a dialect (small language). This dialect is used in some places for funniness. l33tspeak uses numbers, ASCII symbols, and diacritics together to make symbols that look like Latin letters. For example, in the name "David" would translate in 1337 as |)/-\\/1|).
Most of the time it is only the vowels that are changed and then usually only they are replaced by numbers; therefore, it is unusual to see someone use the leet alphabet to spell out a whole word (although there are common exceptions, namely "1337").
These are only examples; these are not mandatory for Leet-speak, which is not officially defined anywhere, like most slangs.
When people write in leet, they spell some words wrong all the time. They might do this to laugh at new people who do not write words with their keyboards well, might just be making fun of English's pronunciation or spelling .
When a person writes in English the person must follow English rules, but most of the time people who write in leet do not use these rules. When they write in leet they try to write it in a special way, so that it is very different from English.
"l33t is teh suck!" (meaning: 'leet sucks') shows that in leet people can use their own rules, and not use the English rules. A lot of times adjectives (describing words) are turned into nouns. The leet word "teh" (the) is also often placed in front of verbs, as in "I teh pwnd j00" (meaning I the owned you, meaning: I beat you badly). another example might be I 4m t3h pwnage!!!!11!!11 (meaning I am the best!)
Leet speakers may also speak normally but without the vowels. Fr xmpl nmbr 1 u cn tll it wrks.= For example, number one you can tell it works.
Because some words are too long for use in games they have been written how they sound. Here's a quick guide:
There are some that are uber 1337...using nothing but symbols and numbers to represent their letters...
Example as follows;
1 4/\/\ 7|-|3 |<33/o3|2 ()|" 7|-|3 \_//\/1\/3|253 (I am the keeper of the universe)
<nowiki>*</nowiki>Much of the intentional misspelling said to be part of 1337 is actually more properly part of chatspeak, a completely different thing.
A waterfall is a place where water rushes down a steep ledge. The water flows from higher land, then it falls down a big step of rock to lower land of softer rock where it will continue on its journey. Usually the lower land is in a gorge. Waterfalls are usually made when a river is young, in places where softer rock is underneath harder rock in the waterfalls
Many people choose them as sacred spots. The roar from a big waterfall is very loud. Some people think it is beautiful music and that a waterfall is one of the most beautiful things in nature.
The highest waterfall in the world is "Angel Falls" in Venezuela where the water falls .
A garden is usually a piece of land that is used for growing flowers, trees, shrubs, and other plants. The act of caring for a garden by watering the flowers and plants and removing the weeds is called gardening.
There are many types of gardens. People have small private gardens in the backyard outside their house. Some gardens are built indoors in malls, public buildings, or greenhouses. Greenhouses are special buildings where plants are grown. A greenhouse has a transparent glass or plastic roof and walls that let sunlight in.
Water gardens are plants that are grown in ornamental (decorative) pools and ponds. People doing water gardening plant water lilies and other aquatic (water) plants.
Gardening can be done outside of the home, as well. There are in city gardens, botanical gardens (places where plants are grown), zoos which have gardens, and theme parks which have gardens. These types of gardens are cared for by people called gardeners or groundskeepers.
Gardens are related to farms (agriculture); both gardens and farms are used for growing plants. But farms are much larger than gardens. A farm may have hundreds of square kilometers of plants and crops. A garden in a person's backyard is usually only measures a few square meters.
Farms are businesses which sell the crops, fruit, and vegetables that are produced. Some gardens are businesses, which charge a fee to enter the garden. However, private gardens in people's backyards are used as a hobby or as a recreation, not as a business.
In addition to plants, many gardens also have landscaping features such as pathways, seats, rock gardens, ponds, fountains, a small stream with or without a waterfall. Some incorporate gazebos and structural designs to accommodate for places to sit or to place a hammock for a siesta. Roman gardens will have its own columns, fountains and statures placed at strategic places depending on its sizes and uses. Japanese gardens have their own unique designs and features.
Some gardens are created in people's backyards, outside their home (note that in Britain the whole area is called a "garden", not a "yard"). People with gardens in their backyards use gardens as a place to do gardening. Gardening is a type of physical activity which can use enough energy and increase your heart rate that it can be rated as a form of exercise for to relax and exercise certain muscles depending on whether on the activity you do that day such as planting, pruning, weeding, or simply just walk around your garden continuously for 15 minutes or more.
Many people find gardens relaxing especially if the garden is full flowers with strong scents. Some flowers like roses, bougainvilleas, orchids and many others are just beautiful to look at. Many people think that gardens are very beautiful and a place to relax and /or entertain. A garden can have a place to barbecue, to sit and to read.
In many countries and cultures, designing pretty gardens is considered to be an art. In Japan, for instance, Zen monks build decorative gardens with stone and waterfall features using natural materials such as bamboo, rock and BONSAI trees like spruce, pine, and other trees with they trained into miniature forms. In Europe in the 1700s, kings and queens had formal gardens built (for example, the gardens at Versailles, France). In China they also feature Chinese forms of gardens. Now some enterprising people start to have herbal gardens to feature useful herbs used in alternative, traditional, and homeopathic medicine
Great Zimbabwe is a ruined city in the south-eastern hills of Zimbabwe. The site is not far from the country's border with Mozambique, which is in the southeast of the African continent.
Greater Zimbabwe was the capital of the Kingdom of Zimbabwe during the country’s later Iron Age. The monument first began to be built in the 11th century, and work continued until the 14th century. It covered an area of 722 hectares (1,780 acres) which might have housed up to 18,000 people. It was a royal city for the Zimbabwean monarch. One of its most prominent features were its walls, some of which were over five metres high and which were constructed without mortar. Eventually the city was abandoned and fell into ruin.
The Kingdom of Zimbabwe included the River Zambezi in the north, the Transvaal in the south and Botswana in the east. The people who lived at Great Zimbabwe controlled trade between the coast and inland Africa. The modern country of Zimbabwe is named after it.
Archaeologists have found goods from as far as China that were used by the people. This shows they bought and sold things over great distances. The city had stopped growing when traders from Portugal came to southern Africa 500 years ago, but nobody is sure why this happened. Europeans at first thought that Great Zimbabwe had been built by foreigners. Now we know it was built by the local people. People who have studied the site have learned much about old Africa.
The earliest known written mention of the ruins was in 1531 by Vicente Pegado, Captain of the Portuguese garrison of Sofala, who recorded it as "Symbaoe". The first visits by Europeans were in the late 19th century, with investigations of the site starting in 1871.
(Machu Picchu is a pre-Columbian 15th-century Inca site in Peru, in South America.
The Incas built the city on a mountain ridge, 2430m above sea level. They lived there between 1200 and 1450 AD. Other people lived there before about 650 AD.
The Incas built houses, fields and temples by cutting the rock on the mountain so it was flat. They built an Observatory to look at the stars).
When the Spanish invaded Peru, the Incas left Machu Picchu. Nobody knows for sure why they did that, but some think it was because of diseases from Europe. The city was left unfinished, most likely due to the Spanish invasion and/or a civil war between the ruling rival Inca brothers named Huascar and Atahualpa. The Spanish never found Machu Picchu or the lost city during their occupation.
(Machu Picchu is very difficult to get to because it is so high in the mountains. It has only one way in and a stone wall to protect it. Most people on Earth did not know it was there until a Yale graduate named Hiram Bingham rediscovered it in 1911). He heard rumours of a hidden city which was already known to the native Peruvians, who guided him there. He led a restoration project that was partly funded by the National Geographic Society. Bingham made a deal with the government to take artifacts to the Peabody Museum for study. Peru is still trying to have those artifacts returned to them.
(Machu Picchu was declared a Peruvian Historical Sanctuary in 1981 and a UNESCO World Heritage Site in 1983. In 2007, Machu Picchu was voted one of the New Seven Wonders of the World in a worldwide Internet poll).
(Today, there is a new road so that tourists can visit. People can also walk along the Inca Trail, or take a train from Cusco.)
Apple Inc. is a multinational company that makes personal computers (the Macintoshes), software (macOS, iOS, watchOS and tvOS), and mobile devices (iPod, iPhone and iPad) like music players. Apple calls its computers "Macintoshes" or "Macs", and it calls its laptops "MacBooks". Their line of mobile music players is called "iPod", their smartphone line is called "iPhone" and their tablet line is called "iPad". Apple sells their products all around the world. Apple Inc. used to be called Apple Computer, Inc., but Apple changed their name after introducing the original iPhone.
Apple Inc. is a public company and trades on the NASDAQ under the stock ticker AAPL. On March 19, 2015, it became one of the 30 components of the Dow Jones Industrial Average.
Apple was started in 1976 by Steve Jobs and Steve Wozniak. Before they made the company, they sold "blue boxes", which had telephone buttons on them. People could use them to make telephone calls from payphones without paying any money. It did this by pretending to be a telephone operator. The company's first product is now called the Apple I computer. They were almost ready to sell it, but a problem happened. Steve Wozniak was working for the computer company Hewlett-Packard, and the papers that said he could work there said he had to give everything he invented to the company before he could do what he wanted to do with it. He showed the first Apple I to the boss at Hewlett-Packard, but they did not want his computer. Wozniak was then free to do what he wanted to do with the Apple I. It began selling in 1976. In 1977, they made their second computer, called the Apple II, which later became very successful compared to Apple I.
Before the iPhone, the most popular product made by Apple was the iPod. It was first sold in 2001, and Apple sold over 100 million in six years. iPods are used to play music. Recent iPod Touches have a LED screens, can take and show pictures, record, view and edit videos, record word and voice memos, can connect to the Internet for features such as e-mail, and downloading apps from the App Store. The latest iPod Touch is made with a 64-bit architecture.
There are several different types of iPods:
The red iPod shuffle, iPod nano, and iPod touch models, and a few more products, are part of the "(PRODUCT) RED" program. This means that some of the profits from these iPods goes to the Global Fund to fight AIDS in Africa.
Apple makes computers. Newer computers by Apple run the OS X operating system, which is included with the Mac.
Apple also makes software for their computers. Some of the software that Apple makes is:
Most computer users in the world use Microsoft Windows, the rival to Mac OS X. About 10% of computer users use Apple's Macintosh computers. It is not legal to run Apple's Mac OS X on a Windows computer. However, it is allowed to run Windows on modern Macintosh computers. Even though Apple makes their computers to run Mac OS X, they also make software that allows you to install Windows. This software is called Boot Camp.
Apple is perhaps most famous for its mobile devices, which are small computers that are easy to carry around. They have touchscreens with multi-touch technology instead of a separate keyboard and mouse. Most of these products run an operating system called iOS. It is very similar to the Android software made by Google. iOS can do a lot of different things, and it does so by running "apps", which are programs similar to those on a PC. Users can download and buy more apps for their device from Apple's App Store.
The iPhone is a mobile phone that can be used to make calls, send text messages, play games and music, show photos and videos (like an iPod), browse the Internet, and do much more. It was one of the first smartphones in the world when the first version was announced in 2007. Apple makes and sells a different model every year, with new models being faster and more powerful and having a newer version of iOS than those that come before them. The newest iPhones released are the iPhone 12 and the iPhone 12 Pro which run on iOS 14. Many cellular carriers around the world sell iPhones, including Sprint, Verizon, AT&T, and T-Mobile in the US.
The iPad is a tablet computer, similar to the iPhone and iPod Touch but with a much larger display - while a typical iPhone has a screen about 4 to 5 inches in size, iPads have screens from 8 to 12 inches big. The first iPad was introduced in 2010 and along with the iPhone, new and better models are made and sold every year. A new iPad will ship with the latest iPad OS software if it is supported.
The Apple Watch is an example of "wearable technology", because it is worn around the wrist in the same way as a traditional wristwatch. However, it is much more than a wristwatch. It not only tells the time and date but also tracks the fitness of the person wearing it and monitors the person's health. It can also do many of the same things that an iPhone can do, such as use Apple's Siri personal assistant, but it needs to be "paired" with an iPhone for it to do these things, meaning that it will not work if you do not have an iPhone. The Apple Watch has many different designs: there is the standard version, a "Sport" version designed for athletes, and an "Edition" version which is made as a fashion product. These all run "watchOS", a modified version of iOS.
The Apple TV is a box that plugs into a TV. It can connect wirelessly to any computer that has the Apple program "iTunes" on it. The Apple TV can play music and show photos or videos from iTunes on the TV. Like other Apple products, Apple TV is regularly updated with new software and features. The most recent version comes with a new remote control and includes the Siri voice assistant. It uses tvOS, a TV version of iOS.
Following several campaigns (for example, Green my Apple), Apple has made their products better for the environment. Previously, the notebook line removed many toxins and improved the products battery life and recharge cycles. Apple products used to ship with chargers and EarPods, but recently Apple has removed the chargers and EarPods from the boxes of most of their products to make the cases smaller. Apple saps they did this to make it easier to make and save resources and energy.
the following individuals sit on the board of Apple Inc.
Since the formation of the Apple Computer Company in 1977, Apple has employed over 95,000 people worldwide. The majority of Apple's employees have been in the United States but Apple has substantial manufacturing, sales, marketing, and support organizations worldwide, with some engineering operations in Paris and Tokyo.
Apple employees include employees of companies Apple owns, and less important, but still relevant companies such as FileMaker Inc. and Braeburn Capital.
Apple Corps has sued Apple Inc. many times for trademark infringement. In the first case, Apple Inc. agreed not to go into the music industry. Apple Corps believes this agreement was broken when Apple Inc. launched the iTunes Store, Apple's online music store.
The two companies had trouble in the past, over the use of the Apple name. They made a deal that Apple Computers would not act as a music company. When Apple Computer Inc. began to sell their iPod, and set up their iTunes music store, Apple Corps believed they had broken their agreement, and took them to court. Apple Computers won the case, but the two companies later worked out a new deal. This deal now means that the Beatles music is now on the iTunes store, whereas it was not there before. Apple Computers was then renamed as Apple Inc. because of its mobile technology business. Steve Jobs, then CEO of Apple, Inc., has said in the past that he loves music from The Beatles, which can be considered to be very ironic.
Soil is loose material which lies on top of the land. It has many things in it, like tiny grains of rock, minerals, water and air. Soil also has living things and dead things in it: "organic matter". Soil is important for life on Earth.
Because soil holds water and nutrients, "it is an ideal place for plants to grow". Soil holds the roots, and lets plants stand above the ground to collect the light they need to live. Almost as important are the fungi. There are fungi which grow into plant roots, a symbiosis known as mycorrhiza. This helps trees grow. There are many other fungi that live by breaking down dead organic material: the remains of other living things. The broken down material is a main source of plant nutrients.
Many animals dig into the soil and make the soil their home. The large animals use soil to make dens for sleeping and giving birth. The small animals live most of their life in the soil. Earthworms are famous for improving soil. This is because the holes they make let air go into the soil. The holes also let water go through.
The soil also has many microorganisms living in it. Many of them eat the organic material in the soil. They use oxygen and release carbon dioxide. They also release mineral nutrients into the soil.
Soil is different in different places on Earth. This is because the climate and rocks in the Earth are different in different places on Earth. Soils are usually thicker in places where ice sheets covered the ground during the Pleistocene ice ages. This is because the ice sheets ground the rock into powder as they slowly moved over the surface.
Soil is made of four things.
Soil has rock pieces made small by wind and rain and sun and snow. The rocks are made of minerals and some of the minerals dissolve in water. Some of the minerals dissolved in water can be used as food by plants. Soil also has dead and living things (organic matter) in it. When a plant dies, it is eaten by animals including bacteria in the soil. When the bacteria are done eating, what is left behind is called humus. When the bacteria die the plant food (minerals) goes back into the soil. A food for plants is called a "plant nutrient". There are many kinds of plant nutrients. Soil has many empty spaces. Half of the soil is space. The spaces are filled with water and air. Water can enter the spaces in the soil. Plants drink the water and the minerals in the water. Plant roots need air to live. If plant roots do not have air, the roots will die. If the plant roots die, the plant will die. A plant that dies is eaten by bacteria and becomes plant nutrients again.
There are many kinds of soil. Each kind of soil has big and small rocks in it and some humus. If rocks in a soil are as big as your fingers, we call those rocks "gravel". Smaller rocks are called sand. Very small rocks are called silt. Very, very small rocks are called clay. You can see sand with your eye. Sand feels rough between your toes. Silt rock is very small and you must use a lens to see silt. Silt rock is smooth between your toes. Clay rock is too small to see with a lens. To see the smallest things you must use a big microscope. You must use a big microscope to see clay too. Clay rock feels slippery between your toes. Most soils contain all kinds of small rocks. The three best rocks for making soil are sand, silt, and clay.
Every soil has different amounts of sand and silt and clay. The mix of sand and silt and clay is the "texture" of the soil. We can also say the mix has a "soil texture". A soil with a lot of sand is called a "sandy soil texture". A soil with a lot of silt is called a "silt soil texture". A soil with a lot of clay is called a "clay soil texture". Farmers like to grow food in the best soil. The best soil is half sand and some silt and a little clay. The organic matter found in the soil is not counted in the soil texture. Only the rocks are counted when we discover the soil texture. Soil texture is very important.
Clay and humus are special parts of the soil. They help keep water and plant food (plant nutrients) in the soil. Water and plant nutrients stick to clay and humus. Water sticks to all of the rock in the soil. But, water sticks best to clay. Water is taken into (absorbed) into humus like a sponge absorbs water. Humus holds a lot of water and plant nutrients. Clay and humus keep water and plant nutrients in the soil. Sand will hold only a little water in the soil. If the soil has too much sand, the water will flow down into the earth. The water that flows down takes plant nutrients down too. The plant roots can not get at the water and plant nutrients if they go too deep. It is best for soil to have a little bit of clay and humus in it for growing plants.
The smallest parts of soil are sand and silt and clay. Those small parts join to make larger parts we call "clumps" or "aggregates". The clumps are made when sand and silt and clay stick together. The humus and clay and minerals in the soil are like glue. The glue sticks the sand and silt and clay together and makes clumps. The clumps make shapes by themselves. Some soils have small round clumps. Other soils have large, hard and flat clumps. The soil with small round clumps is best because it lets in air and water. A little glue is best. If the soil has only a little glue there will be space for water and air and the soil will be soft. If the soil has too much glue the soil will be hard. If the soil has no glue, there will be no space in the soil for air and water. A soil with no spaces is not healthy. Worms in the soil make a slippery glue. When worms make holes in the soil they leave some glue in the soil. Plant roots also make spaces in the soil. When the roots die they leave holes in the soil.
A soil has a "soil texture" (sand and silt and clay) and it has organic matter mixed in it. But weather changes the soil. It is cold on the Earth near the north and south poles. It is hot near the equator of the Earth. Some places on Earth get a lot of rain and some places get no rain. Hot and wet weather make one kind of soil. Cold and dry weather make another kind of soil. Rain water makes small things in the soil move down with the water. When the things in the water get stuck in the soil those things make a layer in the soil. If you dig down into the soil you may find many layers in the soil. The layers may have different colors. The layers may have different "soil textures". The top part of the soil may have a lot of humus and sand. Below that layer there may be a layer of silt. Below that layer there may be a layer of clay.
The sand stays on the top because it is large. The silt goes down a little with the water and makes a layer because it is small. The silt is smaller than some of the spaces in the soil. The clay can go down even lower with the water because it is the smallest. The sand will make one layer, the silt will make another layer and the clay will make another layer. The humus can move down with the water and make a layer too. The silt and clay and humus can move down because of the spaces in the soil. But, the silt, clay, and humus will fill the spaces in the soil. When the spaces in the soil are closed, it makes it hard for air to go into the soil. Plant roots do not go where there is no air. When we dig down we find layers in the soil.
We call those layers "soil horizons". The top horizon may be an inch (25mm) thick. We call that layer the "O" horizon or sometimes "topsoil". The next layer (horizon) is the "B" horizon. The next lower layer of soil is the "C" horizon. The bottom layer has many rocks and may be called the bedrock or "R" horizon for "rock". Deep down, there is always bedrock. But you may have to dig down a mile (a km) or more. When the soil dries, the soil may shrink and cracks will form in the soil. The soil in the top layer may fall down into the cracks. This causes the layers of soil to be changed because they are mixed. There may be many types soil where you live or only one type of soil. Different rocks make different soil textures. Different weather makes the different soil textures different. And so, there are different soils all over the world.
The word organic is used for different things:
3D (or 3-D) means three-dimensional, or having three dimensions. For example, a box is three-dimensional; it is solid, and not thin like a piece of paper. It has volume, a top and bottom, left and right (sides), as well as a front and back. You can turn the box around to view it from another side (called a face, surface or simply side).
A dimension is measurable in inches, microns, miles, kilometers, or any other unit of length.
The three dimensions are often called length (or depth), width (or breadth), and height. Some purposes use other words.
3D graphics are used to make video games or animated movies. Many calculations are needed to make pictures seem three-dimensional on a screen. Modern computers usually have a GPU (Graphics Processing Unit) to handle these calculations.
Binocular vision helps people to see the third dimension easily.
In the Cartesian coordinate system, length, width, and height are given in letters (variables) to make them easier to write, or if a value is not known. Often X is width, Y is height, and Z is length. Other 3D coordinate systems such as spherical coordinates include both linear and angular measurements.
The mathematical study of 3D shapes and dimensions is called solid geometry.
Some people see time as a fourth dimension. It is also measured. It is measured in units of time such as seconds, hours, years, or any other measurement of time.
Humidity means water vapor in the air, but not to liquid droplets in fog, clouds, or rain. Deserts usually have low humidity, and tropical regions have high humidity. The word "humid" often means that the humidity is high, which gives the feeling of being very damp (wet air), stuffy, or even sweltering when the temperature is also high. When the humidity is low, the air can be said to be "not humid" or "dry."
Higher humidity reduces the effectiveness of sweating in cooling the body by reducing the rate of evaporation of moisture from the skin.
The term "relative humidity" is used to note the amount of humidity as a percent, from 0-100%. Meteorologists use hygrometers to measure the humidity in the air.
Humidity affects the rate of evaporation. With a higher humidity, the rate of evaporation is less.
A Calabi–Yau manifold, or 'Calabi–Yau space', is a special type of manifold. It is described in certain branches of mathematics such as algebraic geometry.
The Calabi–Yau manifold's properties, such as Ricci flatness, have applications in theoretical physics. Particularly in superstring theory, the extra dimensions of spacetime might take the form of a 6-dimensional Calabi–Yau manifold. This led to the idea of string theory mirror symmetry.
Quantum mechanics explains how the universe works at a scale smaller than atoms. It is also called quantum physics or quantum theory. Mechanics is the part of physics that explains how things move and "quantum" is the Latin word for 'how much'. A quantum of energy is the least amount possible (or the least extra amount), and quantum mechanics describes how that energy moves or interacts.
Atoms used to be considered the smallest building blocks of matter, but modern science has shown that there are even smaller particles, like protons, neutrons and electrons. Quantum mechanics describes how the particles that make up atoms work.
Quantum mechanics also tells us how electromagnetic waves (like light) work. Wave–particle duality means that particles behave like waves and waves behave like particles. (They are not two kinds of thing, they are something like both: this is their "duality".) Much of modern physics and chemistry can be described and understood using the mathematical rules of quantum mechanics.
The mathematics used to study subatomic particles and electromagnetic waves is very complex because they act in very strange ways.
Photons are particles that are point-sized, smaller than atoms. Photons are like "packets" or packages of energy. Light sources such as candles or lasers produce light in bits called photons.
The more photons a lamp produces, the brighter the light. Light is a form of energy that behaves like the waves in water or radio waves. The distance between the top of one wave and the top of the next wave is called a 'wavelength'. Each photon carries a certain amount, or 'quantum', of energy depending on its wavelength.
A light's color depends on its wavelength. The color violet (the bottom or innermost color of the rainbow) has a wavelength of about 400 nm ("nanometers") which is 0.00004 centimeters or 0.000016 inches. Photons with wavelengths of 10-400 nm are called ultraviolet (or UV) light. Such light cannot be seen by the human eye. On the other end of the spectrum, red light is about 700 nm. Infrared light is about 700 nm to 300,000 nm. Human eyes are not sensitive to infrared light either.
Wavelengths are not always so small. Radio waves have longer wavelengths. The wavelengths for an FM radio can be several meters in length (for example, stations transmitting on 99.5 FM are emitting radio energy with a wavelength of about 3 meters, which is about 10 feet). Each photon has a certain amount of energy related to its wavelength. The shorter the wavelength of a photon, the greater its energy. For example, an ultraviolet photon has more energy than an infrared photon.
Wavelength and frequency (the number of times the wave crests per second) are inversely proportional, which means a longer wavelength will have a lower frequency, and vice versa. If the color of the light is infrared (lower in frequency than red light), each photon can heat up what it hits. So, if a strong infrared lamp (a heat lamp) is pointed at a person, that person will feel warm, or even hot, because of the energy stored in the many photons. The surface of the infrared lamp may even get hot enough to burn someone who may touch it.
Humans cannot see infrared light, but we can feel the radiation in the form of heat. For example, a person walking by a brick building that has been heated by the sun will feel heat from the building without having to touch it.
The mathematical equations of quantum mechanics are abstract, which means it is impossible to know the exact physical properties of a particle (like its position or momentum) for sure. Instead, a mathematical function called the wavefunction provides information about the probability with which a particle has a given property. For example, the wavefunction can tell you what the probability is that a particle can be found in a certain location, but it can't tell you where it is for sure. Because of this uncertainty and other factors, you cannot use classical mechanics (the physics that describe how large objects move) to predict the motion of quantum particles.
Ultraviolet light is higher in frequency than violet light, such that it is not even in the visible light range. Each photon in the ultraviolet range has a lot of energy, enough to hurt skin cells and cause a sunburn. In fact, most forms of sunburn are not caused by heat; they are caused by the high energy of the sun's UV rays damaging your skin cells. Even higher frequencies of light (or electromagnetic radiation) can penetrate deeper into the body and cause even more damage. X-rays have so much energy that they can go deep into the human body and kill cells. Humans cannot see or feel ultraviolet light or x-rays. They may only know they have been under such high frequency light when they get a radiation burn. Areas where it is important to kill germs often use ultraviolet lamps to destroy bacteria, fungi, etc. X-rays are sometimes used to kill cancer cells.
Quantum mechanics started when it was discovered that if a particle has a certain frequency, it must also have a certain amount of energy. Energy is proportional to frequency (E ∝ f). The higher the frequency, the more energy a photon has, and the more damage it can do. Quantum mechanics later grew to explain the internal structure of atoms. Quantum mechanics also explains the way that a photon can interfere with itself, and many other things never imagined in classical physics.
Max Planck discovered the relationship between frequency and energy. Nobody before had ever guessed that frequency is directly proportional to energy (this means that as one of them doubles, the other does, too). Under what are called natural units, then the number representing the frequency of a photon would also represent its energy. The equation would then be:
meaning energy equals frequency.
But the way physics grew, there was no natural connection between the units that were used to measure energy and the units commonly used to measure time (and therefore frequency). So the formula that Planck worked out to make the numbers all come out right was:
or, energy equals h times frequency. This h is a number called Planck's constant after its discoverer.
Quantum mechanics is based on the knowledge that a photon of a certain frequency means a photon of a certain amount of energy. Besides that relationship, a specific kind of atom can only give off certain frequencies of radiation, so it can also only give off photons that have certain amounts of energy.
Isaac Newton thought that light was made of very small things that we would now call particles (he referred to them as "Corpuscles"). Christiaan Huygens thought that light was made of waves. Scientists thought that a thing cannot be a particle and a wave at the same time.
Scientists did experiments to find out whether light was made of particles or waves. They found out that both ideas were right — light was somehow both waves and particles. The Double-slit experiment performed by Thomas Young showed that light must act like a wave. The Photoelectric effect discovered by Albert Einstein proved that light had to act like particles that carried specific amounts of energy, and that the energies were linked to their frequencies. This experimental result is called the "wave-particle duality" in quantum mechanics. Later, physicists found out that everything behaves both like a wave and like a particle, not just light. However, this effect is much smaller in large objects.
Here are some of the people who discovered the basic parts of quantum mechanics: Max Planck, Albert Einstein, Satyendra Nath Bose, Niels Bohr, Louis de Broglie, Max Born, Paul Dirac, Werner Heisenberg, Wolfgang Pauli, Erwin Schrödinger, John von Neumann, and Richard Feynman. They did their work in the first half of the 20th century.
Quantum mechanics formulae and ideas were made to explain the light that comes from glowing hydrogen. The quantum theory of the atom also had to explain why the electron stays in its orbit, which other ideas were not able to explain. It followed from the older ideas that the electron would have to fall in to the center of the atom because it starts out being kept in orbit by its own energy, but it would quickly lose its energy as it revolves in its orbit. (This is because electrons and other charged particles were known to emit light and lose energy when they changed speed or turned.)
Hydrogen lamps work like neon lights, but neon lights have their own unique group of colors (and frequencies) of light. Scientists learned that they could identify all elements by the light colors they produce. They just could not figure out how the frequencies were determined.
Then, a Swiss mathematician named Johann Balmer figured out an equation that told what λ (lambda, for wave length) would be:
where "B" is a number that Balmer determined to be equal to 364.56 nm.
This equation only worked for the visible light from a hydrogen lamp. But later, the equation was made more general:
where "R" is the Rydberg constant, equal to 0.0110 nm, and "n" must be greater than "m".
Putting in different numbers for m and n, it is easy to predict frequencies for many types of light (ultraviolet, visible, and infared). To see how this works, go to Hyperphysics and go down past the middle of the page. (Use H = 1 for hydrogen.)
In 1908, Walter Ritz made the Ritz combination principle that shows how certain gaps between frequencies keep repeating themselves. This turned out to be important to Werner Heisenberg several years later.