AcharyaChanakya/simple-wikipedia huggingface dataset:
Spiders have a two-part body, the front part (cephalothorax) and the abdomen. Unlike insects, spiders do not have antennae. The more advanced spiders have a centralized nervous system, with their ganglia fused into one mass in the cephalothorax. Unlike most arthropods, spiders have no extensor muscles in their limbs, and extend them by hydraulic pressure.
The smallest of full-grown spiders can be less than 4 mm. (0.1 inch). The largest of spiders can have a body length of 10 cm. (4 inches) or more. The largest can weigh 150 grams (5.3 oz). The largest of spiders are the tarantulas and the huntsman spiders. Some huntsman spiders in South East Asia can have a leg span of around 250–300 mm (9.8–11.8 in).
Most spiders have four pairs of eyes on the top-front area of the body, arranged in patterns that vary from one family to another. The main eyes at the front are capable of forming images. Jumping spiders have visual acuity which is ten times better than that of dragonflies, which have by far the best vision among insects. The spiders do this by a telephoto-like series of lenses, a four-layered retina. They can swivel their eyes and put together images from different stages in the scan. The downside is that the scanning and integrating processes are relatively slow.
Spiders and other arthropods have modified their cuticles into elaborate arrays of sensors. Various sensors, mostly bristles, respond to touch, from strong contact to very weak air currents. Chemical sensors provide equivalents of taste and smell. Spiders also have in the joints of their limbs sensors that detect forces and vibrations. In web-building spiders all these mechanical and chemical sensors are more important than the eyes. The eyes are more important to spiders that hunt actively. Like most arthropods, spiders lack balance sensors, and rely on their eyes to tell them which way is up.
The fangs are hollow, like the needles used to give injections. Spiders use their fangs to inject toxins that kill the insects they will eat. Some kinds of spider venom attack the nervous systems of their prey, and other kinds of venom attack body tissues.
Spiders are predators, and eat insects and other arthropods (including other spiders). Most use venom from their fangs to kill their prey. It is rare for spiders to capture prey that are much larger than they are. It is also difficult for most spiders to capture prey that are very much smaller than they are. There are some spiders that form colonies. Spiders eat not only spiders of other species, but spiders of their own species.
The black widow spider got its name because the females sometimes eat the males that mate with them. This may also happen in other species. Each species of spider has its own way of communicating with other spiders they meet. Because of the danger of being eaten, in some species the males have special hooks on their front legs with which they hold the female while they mate. Others bring the female something to eat. There are a few species in which the male spiders construct their own little webs that are connected to the webs of the females. In these species, the male is so much smaller than the female that it would be difficult for her to actually capture the male.
Most spiders have such poor vision that they will not even notice a dead insect. Jumping spiders are one exception to this rule. They have such good vision that they can find recently dead flies or other insects to eat.
Most spiders are predators, but the jumping spider "Bagheera kiplingi" gets over 90% of its food from fairly solid plant material produced by acacias as part of a beneficial relationship with a species of ant.
Young spiders of several families feed on plant nectar. Studies have shown that they do this for long periods. They also clean themselves regularly while feeding. These spiders also prefer sugar solutions to plain water, which shows that they are looking for nutrients. Many spiders are nocturnal, they are most active during the night. The extent of nectar consumption by spiders may therefore have been under-estimated. Nectar contains amino acids, lipids, vitamins and minerals in addition to sugars. Studies have shown that other spider species live longer when nectar is available. Feeding on nectar also avoids the risks of struggles with prey, and the costs of producing venom and digestive enzymes.
Various species are known to feed on dead arthropods (scavenging), web silk, and their own shed exoskeletons. Pollen caught in webs may also be eaten, and studies have shown that young spiders have a better chance of survival if they have the opportunity to eat pollen. In captivity, several spider species are also known to feed on bananas, marmalade, milk, egg yolk and sausages.
The best-known method spiders use to capture prey is a sticky web. The placing of the web allows different spiders to trap different insects in the same area. Flat, horizontal webs allow them to trap insects that fly up from vegetation underneath, for example. Flat vertical nets allow them to trap insects in flight. The spiders that build webs usually do not see very well, but they are very sensitive to vibrations.
Females of the water spider "Argyroneta aquatica" build underwater "diving bell" webs which they fill with air and use eating their prey, molting, mating, and raising offspring. They live almost entirely within the bells, darting out to catch prey animals that touch the bell or the threads that anchor it. A few spiders use the surfaces of lakes and ponds as "webs", detecting trapped insects by the vibrations that these cause while struggling.
Net-casting spiders weave only small webs but then manipulate them to trap prey. They stretch their webs and then release them when prey strike them. Those of the family Deinopidae weave even smaller webs, hold them outstretched between their first two pairs of legs, and lunge and push the webs as much as twice their own body length to trap prey, and this move may increase the webs' area by a factor of up to ten. Experiments have shown that "Deinopis spinosus" has two different techniques for trapping prey: backwards strikes to catch flying insects, whose vibrations it detects; and forward strikes to catch ground-walking prey that it sees. These two techniques have also been observed in other deinopids. Walking insects form most of the prey of most deinopids, but one population of "Deinopis subrufus" appears to live mainly on tipulid flies that they catch with the backwards strike.
Mature female bolas spiders of the genus "Mastophora" build "webs" that consist of only a single "trapeze line", which they patrol. They also construct a bolas made of a single thread, tipped with a large ball of very wet sticky silk. They emit chemicals that resemble the pheromones of moths, and then swing the bolas at the moths. They catch about the same weight of insects per night as web-weaving spiders of similar size. The spiders eat the bolas if they have not made a kill in about 30 minutes, rest for a while, and then make new bolas. Juveniles and adult males are much smaller and do not make bolas. Instead they release different pheromones that attract moth flies, and catch them with their front pairs of legs.
The primitive Liphistiidae, the "trapdoor spiders" (family Ctenizidae) and many tarantulas are ambush predators. They lurk in burrows, often closed by trapdoors and surrounded by networks of silk threads that alert these spiders to the presence of prey. Other ambush predators do without such aids, including many crab spiders. A few species that prey on bees, which see ultraviolet, can adjust their ultraviolet reflectance to match the flowers in which they are lurking. Wolf spiders, jumping spiders, fishing spiders and some crab spiders capture prey by chasing it, and rely mainly on vision to get their prey.
Not all spiders use silk to net their prey. Instead, these spiders may capture insects by grabbing them and then biting them. Among these kinds of spiders the two best known are the wolf spiders and the jumping spiders.
A wolf spider will usually wait until an insect comes near to it, and then rush at the insect, grab it using its front legs, and then bite the insect so that its venom can do its work.
Female wolf spiders lay their eggs on a pad of silk and then draw the edges together to create a round ball that they carry along with them wherever they go. They hold their egg balls to their tail ends by using their silk. When the eggs hatch, the little spiders will crawl onto the mother's back, and she will carry them along with her for days or weeks.
Wolf spiders are very good mothers and will strongly protect both their egg balls and their infants. When the time comes, the little spiders will leave the mother and each will go its own way.
Jumping spiders have very good eyes and can see well. They sneak as close to an insect as they can, and then they jump onto the insect and immediately bite it. Since they often hunt in trees, bushes, and on the sides of walls, if the jumping spider misses it may fall off. But they have a way to save themselves from harm. Before they jump they fasten their silk to the place where they have been standing, and as they jump they let out a silk safety line. So if they fall they will catch themselves when they reach the end of their silk safety line. Sometimes a jumping spider will catch an insect and then fall while still holding onto the insect. But the spider is still safe.
Jumping spiders make little silken "tents" for themselves to sleep in. When they lay eggs they keep them inside such a shelter. They do not take their eggs with them when they go out to hunt.
For all male spiders it is dangerous to seek a mate. The female spider may not realize that the male is a spider of her kind, so she may try to eat it. The jumping spiders not only have visual patterns that identify them to each other, but the male jumping spider will do a special dance when it approaches a female of the same species. That way, the female can recognize that it is a male of her species. She will generally forget about eating for long enough to mate with the visiting male spider.
Jumping spiders have such good eyes that they will usually watch any human who tries to watch them. Some species are very shy and will run away if the human gets too close. But some species, such as Phidippus audax (the audacious or brave jumping spider) and Platycryptus undatus, can become calm if the human comes close to them slowly. Sometimes they will jump onto one of your fingers and then jump from finger to finger and from hand to hand. They seem to want to explore.
Some jumping spiders of the genus "Portia" hunt other spiders in ways that seem intelligent, outflanking their victims or luring them from their webs. Laboratory studies show that "Portia"'s instinctive tactics are only starting points for a trial-and-error approach from which these spiders learn very quickly how to overcome new prey species. However, they seem to be relatively slow thinkers, which is not surprising as their brains are vastly smaller than those of mammalian predators.
Ant-mimicking spiders face several challenges: they generally develop slimmer abdomens and false "waists" to mimic the three distinct regions (tagmata) of an ant's body; they wave the first pair of legs in form to their heads to mimic antennae, which spiders lack, and to conceal the fact that they have eight legs rather than six. They have large color patches round one pair of eyes to disguise the fact that they generally have eight simple eyes, while ants have two compound eyes; they cover their bodies with reflective hairs to resemble the shiny bodies of ants. In some spider species males and females mimic different ant species, as female spiders are usually much larger than males.
Ant-mimicking spiders also modify their behavior to resemble that of the target species of ant, for example many adopt a zig-zag pattern of movement, ant-mimicking jumping spiders avoid jumping, and spiders of the genus "Synemosyna" walk on the outer edges of leaves in the same way as "Pseudomyrmex". Ant-mimicry in many spiders and other arthropods may be for protection from predators that hunt by sight, including birds, lizards and spiders. However several ant-mimicking spiders prey either on ants or on the ants "livestock" such as aphids. When at rest the ant-mimicking crab spider "Amyciaea" does not closely resemble "Oecophylla", but while hunting it imitates the behavior of a dying ant to attract worker ants. After a kill some ant-mimicking spiders hold their victims between themselves and large groups of ants to avoid being attacked.
Spiders reproduce sexually and fertilization is internal but indirect. In other words, the sperm is not inserted into the female's body by the male's genitals but by an intermediate stage. Unlike many land-living arthropods, male spiders do not produce ready-made spermatophores (packages of sperm). Instead, they spin small sperm webs on to which they ejaculate and then transfer the sperm to structures on the tips of their pedipalps. When a male detects signs of a female nearby he checks whether she is of the same species and whether she is ready to mate; for example in species that produce webs or 'safety ropes', the male can identify the species and sex of these objects by smell.
Spiders generally use elaborate courtship rituals to prevent the large females from eating the small males before fertilization, except where the male is so much smaller that he is not worth eating. In some species males mate with newly molted females, which are too weak to be dangerous to the males.
In web-weaving species precise patterns of vibrations in the web are a major part of the rituals, while patterns of touches on the female's body are important in many spiders that hunt actively, and may 'hypnotize' the female. Gestures and dances by the male are important for jumping spiders, which have excellent eyesight. If courtship is successful, the male injects his sperm from the pedipalps into the female's genital opening on the underside of her abdomen. Female reproductive tracts vary. Some are simple tubes, but others have chambers where females store sperm, and release it when they are ready.
Males do get eaten in some species. Males of the genus "Tidarren" cut off one of their palps, and enter adult life with one palp only. The palps are 20% of male's body mass in this species, and detaching one of the two improves mobility. In the Yemeni species "Tidarren argo", the remaining palp is then torn off by the female. The separated palp remains attached to the female's opening for about four hours. In the meantime, the female feeds on the palpless male. In over 60% of cases the female of the Australian redback spider kills and eats the male after it inserts its second palp into the female's genital opening; in fact the males co-operate by trying to impale themselves on the females' fangs. Observation shows that most male redbacks never get an opportunity to mate, and the 'lucky' ones increase the likely number of offspring by ensuring that the females are well-fed. However males of most species survive a few matings, limited mainly by their short life spans. Some even live for a while in their mates' webs.
Females lay up to 3,000 eggs in one or more silk egg sacs, which maintain a fairly constant humidity level. In some species the females die afterwards, but females of other species protect the sacs by attaching them to their webs, hiding them in nests, carrying them in the chelicerae or attaching them to the spinnerets and dragging them along.
Baby spiders pass all their larval stages inside the egg and hatch as spiderlings, very small and sexually immature but similar in shape to adults. Some spiders care for their young, for example a wolf spider's brood cling to rough bristles on the mother's back, and females of some species respond to the "begging" behaviour of their young by giving them their prey, provided it is no longer struggling, or even regurgitate food.
Like other arthropods, spiders have to moult to grow as their cuticle ("skin") cannot stretch. Most spiders live for only one to two years, although some tarantulas can live in captivity for over 20 years.
Of the 40,000 spiders, less than 12 are known to be dangerous to humans. Most of the time, being bitten by a spider is painful. Most spiders use venom to paralyse their prey; they kill it through eating, or through a bite. A few spiders have venoms that can be dangerous to weakened people and those allergic to it. Since 1927, 13 people have died, after a bite from a "Atrax robustus" spider from Australia.
The spider that kills the most people, the black widow and other spiders in the genus "Latrodectus" are around 1 cm. in body length. The "Atrax" and "Phoneutria" spiders, which are also capable of killing people, both average around 2.5 cm. or one inch, and even the Widow spiders are large enough to be easily noticed.
Even relatively small spiders like "Phidippus audax" can give a painful bite if you hurt them, but spiders are very helpful to human beings because they control insects that eat our crops.
Being afraid of spiders is a very common phobia (fear). The widow spiders (black widows and other members of their genus) never willingly leave their webs, so usually people get bitten when they touch the spider by mistake.
Click on a picture to see it larger:
1760s
Grass is a plant with narrow leaves growing from the base. A common kind of grass is used to cover the ground in a lawn and other places. Grass gets water from the roots in the ground. Grasses are monocotyledon plant, herbaceous plants.
The grasses include the "grass", of the family Poaceae (also called Gramineae), as well as the sedges (Cyperaceae) and the rushes (Juncaceae). These three families are not closely related but belong to different clades in the order Poales.
The true grasses include cereals, bamboo and the grasses of lawns (turf) and grassland. Uses for graminoids include food (as grain, sprouted grain, shoots or rhizomes), drink (beer, whisky), pasture for livestock, thatching thatch, paper, fuel, clothing, insulation, construction, sports turf, basket weaving and many others.
Many grasses are short, but some grasses, like bamboo can grow very tall. Plants from the grass family can grow in many places, even if they are very cold or very dry. Several other plants that look similar but are not members of the grass family are also sometimes called grass; these include rushes, reeds, papyrus, and water chestnut.
Grasses are an important food for many animals, like deer, buffalo, cattle, mice, grasshoppers, caterpillars, and many other grazers. Unlike other plants, grasses grow from the bottom, so when animals eat grass they usually do not destroy the part that grows. Without grass, dirt can wash away into rivers (erosion).
Graminoids include some of the most versatile plant life-forms. They became widespread toward the end of the Cretaceous. Fossilized dinosaur dung (coprolites) have been found containing grass phytoliths (silica stones inside grass leaves). Grasses have adapted to conditions in lush rain forests, dry deserts, cold mountains and even intertidal habitats, and are now the most widespread plant type. Grass is a valuable source of food and energy for many animals.
Lawn grass is often planted on sports fields and in the area around a building. Sometimes chemicals and water is used to help lawns to grow.
People have used grasses for a long time. People eat parts of grasses. Corn, wheat, barley, oats, rice and millet are cereals, common grains whose seeds are used for food and to make alcohol such as beer.
Sugar comes from sugar cane, which is also a plant in the grass family. People have grown grasses as food for farm animals for about 4,000 years. People use bamboo to build houses, fences, furniture and other things. Grass plants can also be used as fuel, to cover roofs, and to weave baskets.
In English, the word "grass" appears in several phrases. For example:
Cacao tree
The cacao tree is a small tree originally grown in tropical South America. It only grows to 4 to 8 meters in height. Its seeds are called cocoa and are used to produce cocoa butter, chocolate drinks, and chocolate. Now the trees are grown in plantations in many tropical countries.
Cacao is planted on over 70000 square kilometres worldwide with 40% of production coming from Côte d'Ivoire, Ghana, and Indonesia. Each country produces about 15%, with smaller amounts coming from Brazil, Nigeria, and Cameroon.
A tree begins to bear fruit when it is 4 or 5 years old. In one year, when mature, it may have 6,000 flowers, but only about 20 pods. About 300-600 seeds (10 pods) are required to produce around 1 kg of cocoa paste.
There are three main cultivar groups of cacao beans used to make cocoa and chocolate. The most prized, rare, and expensive is the Criollo Group, the cocoa bean used by the Maya. Only 10% of chocolate is made from the Criollo, which is less bitter and more aromatic than any other bean. The cacao bean in 80% of chocolate is made using beans of the Forastero Group. Forastero trees are significantly hardier than Criollo trees, resulting in cheaper cacao beans. Trinitario, a hybrid of Criollo and Forastero, is used in about 10% of chocolate. For details of processing, see cocoa.
Cacao beans were commonly used as currency in Pre-Columbian Mesoamerica. In some areas, such as Yucatán, they were still used in place of small coins as late as the 1840s.
Mahabad and Piranshahr
Mahabad & Piranshahr (, ); (Old name: سابلاخ: Sablakh, which may be of Mongolian origin) is a city in Iran. It is in the north-west of the country, in the region of Iranian Kurdistan and the province of West Azarbaijan. The city is south of Lake Urmia in a narrow valley 1,300 metres above sea level. It has about 162.434 people who live in the city. Mahabad is connected by road with Tabriz 300 km north, Urmia 150 km north and Arbil, in Iraqi Kurdistan.
The city is one center and symbol of the Kurdish nationalism. The reason is because in 1945 it was the capital of the new founded people's Republic of Mahabad. The republic was conquered by Iranian forces in 16 December 1946. The president was Qazi Muhammad. The majority of the population is Kurdish. During the revolution in Iran, at 3 September 1979 the city was bombed and occupied by Iranian forces. After the death of Shivan Qaderi, a student and opposition activist in July 9 2005, the Kurdish population protested against the Iranian government.
Mahabad has also a branch of Islamic Azad University.
The region of Mukrian consists of Piranshahr and Mahabad.
Shivan Qaderi
Shivan Qaderi (or Sivan Ghaderi or Schuaneh Ghaderi; born 1979 or 1980; died 9 July 2005 in Mahabad) was a student and opposition activist in Iran. After his death in 2005, the Kurds protested and the Iranian government had to send more than 100,000 soldiers to this region. The Kurdistan Democratic Party of Iran reported, that about 50,000 people had protested after his death on the Chuwarchira Square. Humans Rights First say that, after he was shot, Iranian soldiers tied Ghaderi's body "to a military vehicle and dragged it through the city, obviously trying to frighten the population so that they would not organize any more protests."
In cooking, a sauce is a liquid mixture added to another food for flavour. Sauces are not normally eaten by themselves; they add flavour, moisture, and visual appeal to another dish. Sauces are an essential element in cuisines all over the world.
The main sauces of French cuisine are built on a basis of roux, which is just flour and the liquid part of butter. Examples from Italian cuisine are the egg, cheese and ham sauce called "Carbonara"; the ground meat sauce called "bolognese", and the herbs and garlic sauce called "pesto".
Bottled sauces can be poured over food when it is served. An example would be the tomato-based sauce that is usually poured over spaghetti. Gravy is a brown sauce served with meat.
"Sauce" is a French word taken from the Latin "salsus", meaning "salted". Possibly the oldest sauce recorded is "garum", the fish sauce used by the Romans.
Sauces need a liquid component, but some sauces (for example, pico de gallo salsa or chutney) may contain more solid elements than liquid.
Sauces may be used for savoury dishes or for desserts. They can be prepared and served cold, like mayonnaise, prepared cold but served lukewarm like pesto, or can be cooked like bechamel and served warm or again cooked and served cold like apple sauce.
Some sauces are commercial products like Worcestershire sauce, HP sauce, soy sauce or ketchup. In French cuisine they are freshly prepared by the chef. Sauces for salads are called salad dressing. A cook who specializes in making sauces is a saucier.
Sauces in French cuisine date back to the Middle Ages. There were hundreds of sauces in the culinary repertoire, and were a major defining characteristic of French cooking of the 19th and 20th centuries, until nouvelle cuisine.
In the 19th century, the chef Antonin Carême classified sauces into four families, each of which was based on a mother sauce (Also called "grandes sauces"). Carême's four mother sauces were:
In the early 20th century, the chef Auguste Escoffier updated this classification to five mother sauces. They are:
A sauce which is based on one of the mother sauces is sometimes called a small sauce, minor sauce, or secondary sauce. Most sauces commonly used in classical cuisine are small sauces, or derivatives of one of the above-mentioned mother sauces.
Mother sauces are not commonly served as they are; instead they are augmented with additional ingredients to make small (derivative) sauces. For example, Bechamel can be made into Mornay by the addition of Gruyère or any cheese one may like, and Espagnole becomes Bordelaise with the addition and reduction of red wine, shallots, and poached beef marrow.
Spaghetti is a long, string-shaped kind of pasta.
The word "spaghetti" was first used in 1849 as "sparghetti" in Eliza Acton's "Modern Cookery". It comes from Italian "spaghetto", which means "string".
Spaghetti is made from wheat noodles, which are boiled in water for a short time. Spaghetti can either be served as a side dish, or as a main dish. As a main dish, a sauce is added. There are many different kinds of sauces. Simpler ones are made of butter, more complicated ones include tomatos, garlic, olive oil and various other herbs. Different varieties with mussels, fish or meat also exist. Ground Parmesan cheese is often added.
In Italy the sauce is usually mixed with the spaghetti while they are being prepared. Usually, spaghetti are eaten only with a fork, or with a fork and a spoon. Sometimes, they are cut with a knife for small children. Many Italians see using a knife to eat spaghetti as bad manners, except to prepare them for small children.
In the United States, there is a kind of spaghetti called "Alvaro's spaghetti" which is served with alfredo sauce. In some countries,like United States or Canada, meatballs are often in the spaghetti sauce.
In China, spaghetti is often made by hand. In Italy, spaghetti is made with a machine so that large amounts can be made quickly. Italy is the biggest producer and consumer of spaghetti in the world.
It is also a popular dish in Libya.
Spaghetti is called by other words when it has a different thickness: "spaghettini (n. 3)", "spaghetti (n. 5)", and "spaghettoni (n. 8)".
Usually, spaghetti leftovers last in a fridge for around 3 to 5 days, while spaghetti in a freezer will last more than one month.
Emperor penguin
The Emperor penguin ("Aptenodytes forsteri") is a penguin that lives in Antarctica. It is the tallest and heaviest penguin. They are the only birds that can lay their eggs on ice.
Emperors are the biggest of the 18 species of penguin found today, and one of the largest of all birds. They are approximately 120cm tall (about the height of a six year old child) and weigh in at around 40 kg, though their weight does fluctuate dramatically throughout the year.Emperor penguins are about tall, weigh up to , and have a wingspan of . Emperor Penguins are black and white like all penguins, and the sides of their neck and chest are golden. They can dive deeper than any other bird, including other penguins. Emperor penguins are also the largest penguins in the world.Emperors are the biggest of the 18 species of penguin found today, and one of the largest of all birds. There are approximately 595,000 adult Emperor penguins in Antarctica. But due to a lack of research, there is still so much we don't know about these magnificent polar creatures. That's why we're funding research in the Antarctic, because the more we know, the better we can protect them. This will encourage the formation of Marine Protected Areas and will help in protecting the species in the face of climate change. Emperor penguins do not build nests they lay their eggs on the ice through their legs. Like other penguins, emperors leap into the air while swimming, which is called porpoising.
They eat mostly crustaceans, such as krill, and fish but also eat cephalopods, such as squid, cuttlefish, and octopuses.
Emperors live in the coldest climate on earth. Temperatures can drop as low as -140 degrees Fahrenheit (-95.6 °C) on the Antarctic ice. They breed at the beginning of the Antarctic winter (March and April), on the ice all around the Antarctic continent. They live in large groups, called colonies, that can have up to 20,000 birds. They huddle close together to keep warm. Emperor penguins live for about 20 years, although some have been known to live for 40 years. They dive at their food and they stay in small groups
The shape of their body helps them to survive. They have short wings that help them swim and to dive up to to catch larger fish. The deepest dive recorded is . They can swim up to for a short time, which lets them escape their main enemy, the leopard seal. They can stay warm because they have a thick layer of blubber. The layer of downy feathers trap air that keeps the body heat in and cold air and water out. They also have large amounts of body oil that help in keeping them dry in the water.
While they are very fast in the water, on land the birds can only walk very slowly. On ice they can lie on their stomachs and use their wings to slide along, like a sled.
Emperor penguins spend most of their time in the water, coming to the shore to breed. There is nothing on the ice to make a nest, so after the female lays her one egg in winter, the male puts the egg on his feet to keep it warm until spring. This can be from 65 to 75 days. He has a special fold of skin on his stomach which can fold over and cover the egg to keep it warm. This is a difficult action to swap the egg from the female to the male; if it sits for too long on the ice it will freeze. He does not eat during this time, and can lose up to half his weight. To keep warm, all the male penguins huddle together. Those on the outside of the group will slowly shuffle their way into the middle; the group is always moving and can move as much as in 24 hours. The female comes back in spring when the egg hatches, while the male will go back to sea to eat, but comes back to help look after the chick. The chick lives on its parents feet for about 50 days until it becomes strong enough to survive the cold.
The Australian movie "Happy Feet" was based on the story of an emperor penguin who is unable to sing and get a mate because he was left for too long on the ice when still an egg.
Snares penguin
The Snares penguin ("Eudyptes robustus"), is a crested penguin. It is probably a subspecies of the Fiordland penguin. It is a penguin from New Zealand. It is between 50 and 70 centimetres in height and weighs between 2.5 and 4 kilograms.
It breeds on The Snares, a small island group south of New Zealand's South Island.
Chuar-chira Square
Chuar-chira Square (, ) (meaning "Square of the four candles"), is a known square in center of city of Mahabad where after Iranian invasion in 1947, Qazi Muhammad the president of Republic of Mahabad was hanged in public as well as other leaders of the republic in Mahabad and Bukan. In 2005 the Kurdistan Democratic Party of Iran reported that about 50.000 persons had demonstrated against the Iranian gouverment. The reason was the death of Shivan Qaderi.
It is now officially called Shardari Square. This square is one of the oldest places of Mahabad city.
A complex number is a number, but is different from common numbers in many ways. A complex number is made up using two numbers combined together. The first part is a real number, and the second part is an imaginary number. The most important imaginary number is called formula_1, defined as a number that will be -1 when squared ("squared" means "multiplied by itself"): formula_2. All the other imaginary numbers are formula_1 multiplied by a real number, in the same way that all real numbers can be thought of as 1 multiplied by another number. Arithmetic functions such as addition, subtraction, multiplication, and division can be used with complex numbers. They also follow commutative, associative and distributive properties, just like real numbers. The set of complex numbers is often represented using the symbol formula_4.
Complex numbers were discovered while attempting to solve special equations that have exponents in them. These began to pose real problems for mathematicians. As a comparison, using negative numbers, it is possible to find the "x" in the equation formula_5 for all real values of "a" and "b", but if only positive numbers are allowed for "x", it is sometimes impossible to find a positive "x", as in the equation .
With exponentiation, there is a difficulty to be overcome. There is no real number that gives −1 when it is squared. In other words, −1 (or any other negative number) has no real square root. For example, there is no real number formula_6 that solves the equation formula_7. To solve this problem, mathematicians introduced a symbol "i" and called it the "imaginary unit". This is the imaginary number that will give −1 when it is squared.
The first mathematicians to have thought of this were probably Gerolamo Cardano and Raffaele Bombelli. They lived in the 16th century. It was probably Leonhard Euler who introduced writing formula_8 for that number.
All complex numbers can be written as formula_9 (or formula_10), where "a" is called the "real part" of the number, and "b" is called the "imaginary part". We write formula_11 or formula_12 for the real part of a complex number formula_13. So, if formula_14, we write formula_15. Similarly, we write formula_16 or formula_17 for the imaginary part of a complex number formula_13; formula_19, for the same . Every real number is also a complex number; it is a complex number with formula_20.
A complex number can also be written as an ordered pair , where both "a" and "b" are real numbers. Any real number can simply be written as formula_21, or as the pair .
Sometimes, formula_22 is written instead of formula_1. In electrical engineering for instance, formula_1 means electric current, so writing formula_1 can cause a lot of problems because some numbers in electrical engineering are complex numbers.
The set of all complex numbers is usually written as formula_4.
Addition, subtraction, multiplication and exponentiation (raising numbers to exponents) are all possible with complex numbers. Division is also possible with complex numbers—as long as the divisor is not zero, Some other calculations are also possible with complex numbers.
The rule for addition and subtraction of complex numbers is pretty simple:
Let formula_27, then formula_28, and formula_29.
Multiplication is a bit different:
Another notable operation for complex numbers is "conjugation". A complex conjugate formula_31 to formula_14 is formula_33.
It is pretty simple, but is important for calculations, because formula_34 is actually a real number for "all" complex formula_13:
Because of that, we can use it to do division:
Complex numbers can be shown on a so-called complex plane. If you have a number formula_14, you can go to point "a" on the real axis and point "b" on the imaginary axis, and draw a vector from formula_40 to formula_41. The length of this vector can be calculated using the Pythagorean theorem, and the angle of this vector is simply the angle between the positive real axis and this vector—going counterclockwise. The length of a vector for a number formula_13 is called its modulus or absolute value (written as formula_43), and the angle is called its argument (formula_44).
This leads to the trigonometrical form of describing complex numbers: by the definitions of sine and cosine, it follows that for all formula_13:
This is closely connected to De Moivre's formula.
There exists even another form, called exponential form.
With the introduction of complex numbers to math, every polynomial with complex coefficients has roots in complex numbers. This introduction also helped to open a path to the creation of another kind of numbers, which could help resolve and explain many different problems. These include the , , , and many others. For more, see .
Frederick I of Prussia
Siege of Jerusalem (1187)
The Siege of Jerusalem took place from September 20 to October 2, 1187. It was part of the war called the Third Crusade.
Balian of Ibelin defended Jerusalem against the armies of Saladin. When he surrendered, the Muslims enslaved thousands of Christians but let many leave after they bought their freedom.
A fictionalized version of the siege (attack) is seen in the movie "Kingdom of Heaven", directed by Ridley Scott.
The Beer Hall Putsch was a failed coup d'état in Munich, Germany between the evening of 8 November and the morning of 9 November 1923. The Nazi Party under Adolf Hitler tried to take over the government of Bavaria, a state in Germany. They began trying to do this by taking several hundred people hostage in a beer hall (a large building where people got together to drink beer and sometimes listen to political speeches). Several Nazis died when they got into a gun fight with police officers in another part of Munich, and Hitler then went to prison for eight months.
Hitler chose to do this for many reasons. The Weimar Republic of Germany was weak because of fighting between right and left-wing parties. Inflation had also left the Weimar Republic with very little support from the people, or money to keep working (paying bills, or even paying pensions and wages). This happened because when Germany lost World War I, other countries made Germany pay for the entire war, and Germany had to make taxes very high so it could pay for the war. This hurt the economy of Germany.
The Nazi Party was getting very strong. Hitler was a strong leader. In 1923, the year when the Weimar Republic was least popular, the Nazi Party grew from 6,000 members to 55,000 members.
Hitler also wanted to copy Mussolini, who had taken power in Italy by marching into Rome.
8 November 1923 - Hitler and his men charged into the Beer Hall and forced the people there to support him. Hitler's men, the SA took over the Army Headquarters, but forgot to take over the telegraph office. This meant that anybody could call in the police.
9 November 1923 - 16 Nazis and 4 Bavarian State Police officers were killed in a gunfight between the Nazis and the police in "Residenzstraße". Hitler was arrested two days later.
Hitler and several of his friends were taken to court for treason, because they took up arms against the government. In the end, Hitler was sent to prison for about eight months, and the Nazi Party broke up (however, it would later get back together).
More people learned about Hitler. Before this happened, he was unknown. But after this, he was a hero to many. Many Germans at that time wanted a strong leadership after the governments of the Weimar Republic.
Hitler also took the time he had to spend in prison to write a book, called Mein Kampf or "My Struggle". It sold millions and told people about his ideas. Mein Kampf also made Hitler popular. (Hitler did not actually write the words down himself. Instead, he told another Nazi, Rudolf Hess, what to write down, and Hess wrote the words down.)
Hitler also had to re-think his strategy. He realised he could not take power the same way that Mussolini had done. Instead, he had to get power through being elected.
The people who died during the Putsch are seen as the first to die for the Nazi Party and are mentioned in Mein Kampf as Martyrs.
Verona is a city in the Veneto region of Italy with 260,000 inhabitants. It is famous for being the setting for the Shakespeare play "Romeo and Juliet" and because of the Roman Arena. This city is built on the Adige river. It has a humid subtropical climate ("Cfa" in the Köppen climate classification).
Kyiv
Kyiv or Kiev () is the capital and largest city of Ukraine. Almost three million people live there.
The city hosted the UEFA Euro 2012 final. Kyiv also hosted the Eurovision Song Contest in 2017.
Kyiv has a humid continental climate ("Dfb" in the Köppen climate classification).
Harare is the capital of Zimbabwe. It is home to over 1.6 million people. It was known as "Salisbury" from its foundation on September 12, 1890 until April 18, 1982.
Harare is Zimbabwe's leading financial, commercial, and communications centre, and a trade centre for tobacco, maize, cotton, and citrus fruits. Manufactured goods include textiles, steel and chemicals, and gold is mined in the area. The city's suburbs include Borrowdale, Mount Pleasant and Avondale. The richest neighbourhoods are to the north. The University of Zimbabwe, the country's oldest university (founded in 1952), is in Mount Pleasant, about 6 km (3.7 mi) north of the city centre. The country's main Test cricket ground, Harare Sports Club is in the city. The Dynamos F.C. in Harare is Zimbabwe's most successful association football team.
Seventh-day Adventist Church
The Seventh-day Adventist Church is a Protestant Christian group. It is different from most other Protestant groups because the followers believe that the seventh day of the week, Saturday, is the day to rest from working and worship God. The Bible calls this day the "Sabbath". The Sabbath is the seventh day of the week (Gen 2:1-3) in Judaism and in the Seventh-Day Adventist Church. This is why they are called "Seventh-day Adventists". Although the abbreviation "SDA" is commonly used, "Adventist" is the church's preferred shortening of "Seventh-day Adventist".
The Seventh-day Adventist Church came from the Millerite movement in the United States. This included people from many denominations. The Millerites started in the middle part of the 19th century. The Millerites were people who followed the teachings of William Miller. Miller preached that Jesus is coming very soon, in the Second Coming or Second Advent. The church name "Adventist" came from the word "Advent." The Seventh-day Adventist Church started in 1863.
In many ways, the religious teachings of the Seventh-day Adventist church are like evangelical teachings such as the Trinity and Biblical inerrancy. Teachings that are different include the doctrine of an investigative judgment, the unconscious state of the dead (which means that when people die, they will not wake up until Christ resurrects them), and that the wicked will be destroyed forever by fire (rather than forever burn in Hell).
The church is also known for its message on health. It teaches that being healthy helps us to make good decisions, understand God’s Word, be productive in God’s service, and otherwise glorify God with our bodies as temples. Adventists who eat meat typically do not eat meat from pigs, certain fish, and other animals that the Bible names as unclean. Many Adventists are vegetarian (no meat) or vegan (no animal products, such as milk or eggs). They tend to stay away from smoking, drinking and other things known to be harmful or mind-altering. Exercise, being outdoors, resting, and drinking lots of water are other parts to healthy living usually taught by Adventists. In 2005, a National Geographic cover story identified the Adventists living in Loma Linda, California, as one of five Blue Zones of people living longer than the rest of the world.
The church also promotes religious liberty. When it comes to culture, it is more conservative.
Among the founders of the Church was Ellen G. White. She wrote many texts that are still thought to be very important in the church today. She was a dedicated Christian who believed she got visions from God about the end of the world and what heaven will be like.
At a world level, the Seventh-day Adventist Church is run by a General Conference. Smaller regions are administered by divisions, union conferences and local conferences. It is present in over 200 countries and territories and is ethnically and culturally diverse. The church runs many schools, hospitals and publishing houses worldwide, as well as a famous organization that helps people in trouble, known as the Adventist Development and Relief Agency (ADRA). There are about 18.5 million people in the Seventh-day adventist church worldwide.
The Seventh-day Adventist Church is organized with a representative form of church government and the world-wide Church has 13 Divisions.
The Seventh-day Adventist World Church Statistics shows a growing church with 15,660,347 members as of December 31, 2007.
The Adventist News Network reported in June 2010 (during the 59th quinquennial General Conference Session of the Seventh-day Adventist Church held in Atlanta, Georgia, U.S.A.) that Seventh-day Adventists reached a membership of 16,300,000, according to the church's Office of Archives and Statistics. The world church Secretary stated that when counting unbaptized children and family members who attend services, the church numbers between 25 and 30 million.
Seventh-day Adventists believe in Protestantism.
Seventh-day Adventist believe in the 28 Fundamental Beliefs. This statement of beliefs was adopted by the General Conference in 1980, with an extra belief (number 11) being added in 2005.
Lye
Lye is the name of different things:
Het Wilhelmus
"Het Wilhelmus", fully known as "Wilhelmus van Nassouwe", is the national anthem of the Netherlands and the former national anthem of the Netherlands Antilles until 1964. Known since at least the 16th century – around the time of the Dutch Revolt – this song contains the oldest melody among all national anthems of the world. Its lyrics also date back to the 1500s, though the lyrics of "Kimigayo"—Japan's national anthem—are much older. Because "Het Wilhelmus" is so old, the origins of the composer(s) and author(s) are uncertain, but the melody has been arranged by Dutch composer Adrianus Valerius in the 1600s. It wasn't officially adopted as national anthem of the Netherlands until the 20th century.
1661 was a common year starting on a Saturday in the Gregorian calendar, and a common year starting on a Tuesday in the Julian calendar.
1579
1005 (MV) was a common year when the Julian calendar was used. It was the fifth year of the 2nd millennium and the 11th century.
984
1003 (MIII) was a common year when the Julian calendar was used. It was the third year of the 2nd millennium and the 11th century.
Fuzzy logic is a sort of computer logic that is different from boolean algebra founded by Lotfi A. Zadeh. It is different in the way that it allows values to be more accurate than on or off. While boolean logic only allows true or false, fuzzy logic allows all things in between. An example of this could be a computer game: A person is standing in a doorway while a thing explodes. The character is hit or not hit if boolean logic is used, but the doorway protects him from the explosion. Therefore, he might only be hit 20%, and takes less damage.
To put it in more precise mathematical terms, classical logic has two values. These values are usually called "false" (0) or "true" (1). With fuzzy logic, a (calculated) value of 0.8 or 0.971 is possible. It is important to know the difference between fuzzy logic and chance. A coin that is thrown has a chance of 0.5 for landing heads up. If it is thrown 1000 times, it is expected that it will land with heads side up 500 times. With fuzzy logic, a thing with a "truth value" of 0.5 will have a value of 0.5 no matter how many times it is done. It is not a 50% chance of true or untrue, it is 50% true and 50% untrue at the same time.
Fuzzy logic is used a lot in expert systems and neural networks.