Koala

The koala is an arboreal herbivorous marsupial native to Australia. It is the only extant representative of the family Phascolarctidae and its closest living relatives are the wombats. The koala is found in coastal areas of the mainland's eastern and southern regions, inhabiting Queensland, New South Wales, Victoria, and South Australia. It is easily recognisable by its stout, tailless body and large head with round, fluffy ears and large, spoon-shaped nose. The koala has a body length of 60–85 cm (24–33 in) and weighs 4–15 kg (9–33 lb). Pelage colour ranges from silver grey to chocolate brown. Koalas from the northern populations are typically smaller and lighter in colour than their counterparts further south. These populations possibly are separate subspecies, but this is disputed.

Koalas typically inhabit open eucalypt woodlands, and the leaves of these trees make up most of their diet. Because this eucalypt diet has limited nutritional and caloric content, koalas are largely sedentary and sleep up to 20 hours a day. They are asocial animals, and bonding exists only between mothers and dependent offspring. Adult males communicate with loud bellows that intimidate rivals and attract mates. Males mark their presence with secretions from scent glands located on their chests. Being marsupials, koalas give birth to underdeveloped young that crawl into their mothers' pouches, where they stay for the first six to seven months of their lives. These young koalas, known as joeys, are fully weaned around a year old. Koalas have few natural predators and parasites, but are threatened by various pathogens, such as Chlamydiaceae bacteria and the koala retrovirus, as well as by bushfires and droughts.

Koalas were hunted by indigenous Australians and depicted in myths and cave art for millennia. The first recorded encounter between a European and a koala was in 1798, and an image of the animal was published in 1810 by naturalist George Perry. Botanist Robert Brown wrote the first detailed scientific description of the koala in 1814, although his work remained unpublished for 180 years. Popular artist John Gould illustrated and described the koala, introducing the species to the general British public. Further details about the animal's biology were revealed in the 19th century by several English scientists. Because of its distinctive appearance, the koala is recognised worldwide as a symbol of Australia. Koalas are listed as of Least Concern by the International Union for Conservation of Nature. The Australian government lists populations in Queensland and New South Wales as Vulnerable. The animal was hunted heavily in the early 20th century for its fur, and large-scale cullings in Queensland resulted in a public outcry that initiated a movement to protect the species. Sanctuaries were established, and translocation efforts moved to new regions koalas whose habitat had become fragmented or reduced. The biggest threat to their existence is habitat destruction caused by agriculture and urbanisation.

The koala is a stocky animal with a large head and vestigial or non-existent tail. It has a body length of 60–85 cm (24–33 in) and a weight of 4–15 kg (9–33 lb), making it among the largest arboreal marsupials. Koalas from Victoria are twice as heavy as those from Queensland. The species is sexually dimorphic, with males 50% larger than females. Males are further distinguished from females by their more curved noses and the presence of chest glands, which are visible as hairless patches. As in most marsupials, the male koala has a bifurcated penis, and the female has two lateral vaginas and two separate uteri. The male's penile sheath contains naturally occurring bacteria that play an important role in fertilisation. The female's pouch opening is tightened by a sphincter that keeps the young from falling out.

The pelage of the koala is thicker and longer on the back, and shorter on the belly. The ears have thick fur on both the inside and outside. The back fur colour varies from light grey to chocolate brown. The belly fur is whitish; on the rump it is dappled whitish, and darker at the back. The koala has the most effective insulating back fur of any marsupial and is highly resilient to wind and rain, while the belly fur can reflect solar radiation. The koala's curved, sharp claws are well adapted for climbing trees. The large forepaws have two opposable digits (the first and second, which are opposable to the other three) that allow them to grasp small branches. On the hindpaws, the second and third digits are fused, a typical condition for members of the Diprotodontia, and the attached claws (which are still separate) are used for grooming. As in humans and other primates, koalas have friction ridges on their paws. The animal has a sturdy skeleton and a short, muscular upper body with proportionately long upper limbs that contribute to its climbing and grasping abilities. Additional climbing strength is achieved with thigh muscles that attach to the shinbone lower than other animals. The koala has a cartilaginous pad at the end of the spine that may make it more comfortable when it perches in the fork of a tree.

Mounted skeleton
The koala has one of the smallest brains in proportion to body weight of any mammal, being 60% smaller than that of a typical diprotodont, weighing only 19.2 g (0.68 oz). The brain's surface is fairly smooth, typical for a "primitive" animal. It occupies only 61% of the cranial cavity and is pressed against the inside surface by cerebrospinal fluid. The function of this relatively large amount of fluid is not known, although one possibility is that it acts as a shock absorber, cushioning the brain if the animal falls from a tree. The koala's small brain size may be an adaptation to the energy restrictions imposed by its diet, which is insufficient to sustain a larger brain. Because of its small brain, the koala has a limited ability to perform complex, unfamiliar behaviours. For example, when presented with plucked leaves on a flat surface, the animal cannot adapt to the change in its normal feeding routine and will not eat the leaves. The koala's olfactory senses are normal, and it is known to sniff the oils of individual branchlets to assess their edibility. Its nose is fairly large and covered in leathery skin. Its round ears provide it with good hearing, and it has a well-developed middle ear. A koala's vision is not well developed, and its relatively small eyes are unusual among marsupials in that the pupils have vertical slits. Koalas make use of a novel vocal organ to produce low-pitched sounds (see social spacing, below). Unlike typical mammalian vocal cords, which are folds in the larynx, these organs are placed in the velum (soft palate) and are called velar vocal cords.

Teeth of a koala, from left to right: molars, premolars (dark), diastema, canines, incisors
The koala has several adaptations for its eucalypt diet, which is of low nutritive value, of high toxicity, and high in dietary fibre. The animal's dentition consists of the incisors and cheek teeth (a single premolar and four molars on each jaw), which are separated by a large gap (a characteristic feature of herbivorous mammals). The incisors are used for grasping leaves, which are then passed to the premolars to be snipped at the petiole before being passed to the highly cusped molars, where they are shredded into small pieces. Koalas may also store food in their cheek pouches before it is ready to be chewed. The partially worn molars of middle-aged koalas are optimal for breaking the leaves into small particles, resulting in more efficient stomach digestion and nutrient absorption in the small intestine, which digests the eucalyptus leaves to provide most of the animal's energy. A koala sometimes regurgitates the food into the mouth to be chewed a second time.

Unlike kangaroos and eucalyptus-eating possums, koalas are hindgut fermenters, and their digestive retention can last for up to 100 hours in the wild, or up to 200 hours in captivity. This is made possible by the extraordinary length of their caecum—200 cm (80 in) long and 10 cm (4 in) in diameter—the largest proportionally of any animal. Koalas can select which food particles to retain for longer fermentation and which to pass through. Large particles typically pass through more quickly, as they would take more time to digest. While the hindgut is proportionally larger in the koala than in other herbivores, only 10% of the animal's energy is obtained from fermentation. Since the koala gains a low amount of energy from its diet, its metabolic rate is half that of a typical mammal, although this can vary between seasons and sexes. The koala conserves water by passing relatively dry faecal pellets high in undigested fibre, and by storing water in the caecum.

Great Pyramid of Giza

The Great Pyramid of Giza (also known as the Pyramid of Khufu or the Pyramid of Cheops) is the oldest and largest of the three pyramids in the Giza pyramid complex bordering what is now El Giza, Egypt. It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact.

Based on a mark in an interior chamber naming the work gang and a reference to fourth dynasty Egyptian Pharaoh Khufu, Egyptologists believe that the pyramid was built as a tomb over a 10 to 20-year period concluding around 2560 BC. Initially at 146.5 metres (481 feet), the Great Pyramid was the tallest man-made structure in the world for more than 3,800 years. Originally, the Great Pyramid was covered by casing stones that formed a smooth outer surface; what is seen today is the underlying core structure. Some of the casing stones that once covered the structure can still be seen around the base. There have been varying scientific and alternative theories about the Great Pyramid's construction techniques. Most accepted construction hypotheses are based on the idea that it was built by moving huge stones from a quarry and dragging and lifting them into place.

There are three known chambers inside the Great Pyramid. The lowest chamber is cut into the bedrock upon which the pyramid was built and was unfinished. The so-called Queen's Chamber and King's Chamber are higher up within the pyramid structure. The main part of the Giza complex is a setting of buildings that included two mortuary temples in honour of Khufu (one close to the pyramid and one near the Nile), three smaller pyramids for Khufu's wives, an even smaller "satellite" pyramid, a raised causeway connecting the two temples, and small mastaba tombs surrounding the pyramid for nobles.

It is believed the pyramid was built as a tomb for Fourth Dynasty Egyptian pharaoh Khufu (often Hellenicised as "Cheops") and was constructed over a 20-year period. Khufu's vizier, Hemon, or Hemiunu, is believed by some to be the architect of the Great Pyramid. It is thought that, at construction, the Great Pyramid was originally 280 Egyptian cubits tall (146.5 metres (480.6 ft)), but with erosion and absence of its pyramidion, its present height is 138.8 metres (455.4 ft). Each base side was 440 cubits, 230.4 metres (755.9 ft) long. The mass of the pyramid is estimated at 5.9 million tonnes. The volume, including an internal hillock, is roughly 2,500,000 cubic metres (88,000,000 cu ft). Based on these estimates, building the pyramid in 20 years would involve installing approximately 800 tonnes of stone every day. Additionally, since it consists of an estimated 2.3 million blocks, completing the building in 20 years would involve moving an average of more than 12 of the blocks into place each hour, day and night. The first precision measurements of the pyramid were made by Egyptologist Sir Flinders Petrie in 1880–82 and published as The Pyramids and Temples of Gizeh. Almost all reports are based on his measurements. Many of the casing stones and inner chamber blocks of the Great Pyramid fit together with extremely high precision. Based on measurements taken on the northeastern casing stones, the mean opening of the joints is only 0.5 millimetre wide (1/50 of an inch).

Great Pyramid of Giza from a 19th-century stereopticon card photo
The pyramid remained the tallest man-made structure in the world for over 3,800 years, unsurpassed until the 160-metre-tall (520 ft) spire of Lincoln Cathedral was completed c. 1300. The accuracy of the pyramid's workmanship is such that the four sides of the base have an average error of only 58 millimetres in length. The base is horizontal and flat to within ±15 mm (0.6 in). The sides of the square base are closely aligned to the four cardinal compass points (within four minutes of arc) based on true north, not magnetic north, and the finished base was squared to a mean corner error of only 12 seconds of arc. The completed design dimensions, as suggested by Petrie's survey and subsequent studies, are estimated to have originally been 280 royal cubits high by 440 cubits long at each of the four sides of its base. The ratio of the perimeter to height of 1760/280 royal cubits equates to 2π to an accuracy of better than 0.05% (corresponding to the well-known approximation of π as 22/7). Some Egyptologists consider this to have been the result of deliberate design proportion. Verner wrote, "We can conclude that although the ancient Egyptians could not precisely define the value of π, in practice they used it". Petrie, author of Pyramids and Temples of Gizeh concluded: "but these relations of areas and of circular ratio are so systematic that we should grant that they were in the builder's design". Others have argued that the Ancient Egyptians had no concept of pi and would not have thought to encode it in their monuments. They believe that the observed pyramid slope may be based on a simple seked slope choice alone, with no regard to the overall size and proportions of the finished building.

In 2013 rolls of papyrus were discovered written by some of those who delivered stone and other construction materials to Khufu's brother at Giza.

Many alternative, often contradictory, theories have been proposed regarding the pyramid's construction techniques. Many disagree on whether the blocks were dragged, lifted, or even rolled into place. The Greeks believed that slave labour was used, but modern discoveries made at nearby workers' camps associated with construction at Giza suggest that it was built instead by tens of thousands of skilled workers. Verner posited that the labour was organized into a hierarchy, consisting of two gangs of 100,000 men, divided into five zaa or phyle of 20,000 men each, which may have been further divided according to the skills of the workers.

One mystery of the pyramid's construction is its planning. John Romer suggests that they used the same method that had been used for earlier and later constructions, laying out parts of the plan on the ground at a 1-to-1 scale. He writes that "such a working diagram would also serve to generate the architecture of the pyramid with precision unmatched by any other means". He also argues for a 14-year time span for its construction.

A modern construction management study, in association with Mark Lehner and other Egyptologists, estimated that the total project required an average workforce of 14,567 people and a peak workforce of 40,000. Without the use of pulleys, wheels, or iron tools, they used critical path analysis to suggest that the Great Pyramid was completed from start to finish in approximately 10 years.

The original entrance to the Great Pyramid is 17 metres (56 ft) vertically above ground level and 7.29 metres (23.9 ft) east of the center line of the pyramid. From this original entrance, there is a Descending Passage 0.96 metres (3.1 ft) high and 1.04 metres (3.4 ft) wide, which goes down at an angle of 26° 31'23" through the masonry of the pyramid and then into the bedrock beneath it. After 105.23 metres (345.2 ft), the passage becomes level and continues for an additional 8.84 metres (29.0 ft) to the lower Chamber, which appears not to have been finished. There is a continuation of the horizontal passage in the south wall of the lower chamber; there is also a pit dug in the floor of the chamber. Some Egyptologists suggest that this Lower Chamber was intended to be the original burial chamber, but Pharaoh Khufu later changed his mind and wanted it to be higher up in the pyramid.

At 28.2 metres (93 ft) from the entrance is a square hole in the roof of the Descending Passage. Originally concealed with a slab of stone, this is the beginning of the Ascending Passage. The Ascending Passage is 39.3 metres (129 ft) long, as wide and high as the Descending Passage and slopes up at almost precisely the same angle. The lower end of the Ascending Passage is closed by three huge blocks of granite, each about 1.5 metres (4.9 ft) long. At the start of the Grand Gallery on the right-hand side there is a hole cut in the wall. This is the start of a vertical shaft which follows an irregular path through the masonry of the pyramid to join the Descending Passage. Also at the start of the Grand Gallery there is the Horizontal Passage leading to the "Queen's Chamber". The passage is 1.1m (3'8") high for most of its length, but near the chamber there is a step in the floor, after which the passage is 1.73 metres (5.7 ft) high.

Killer whale

The killer whale (Orcinus orca), also referred to as the orca whale or orca, and less commonly as the blackfish or grampus, is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. Killer whales are found in all oceans, from Arctic and Antarctic regions to tropical seas. Killer whales have a diverse diet, although individual populations often specialize in particular types of prey. Some feed exclusively on fish, while others hunt marine mammals like pinnipeds, and even large whales. They have been known to attack baleen whale calves. Killer whales are regarded as apex predators, lacking natural predators.

Killer whales are highly social; some populations are composed of matrilineal family groups which are the most stable of any animal species. Their sophisticated hunting techniques and vocal behaviours, which are often specific to a particular group and passed across generations, have been anthropomorphically described as manifestations of culture.

The IUCN currently assesses the orca's conservation status as data deficient because of the likelihood that two or more killer whale types are separate species. Some local populations are considered threatened or endangered due to prey depletion, habitat loss, pollution (by PCBs), capture for marine mammal parks, and conflicts with fisheries. In late 2005, the "southern resident" population of killer whales that inhabits British Columbia and Washington state waters were placed on the U.S. Endangered Species list.

Wild killer whales are not considered a threat to humans, but there have been cases of captive orcas killing or injuring their handlers at marine theme parks. Killer whales feature strongly in the mythologies of indigenous cultures, with their reputation ranging from being the souls of humans to merciless killers.

List of countries by GDP (PPP) per capita

This article includes three lists of countries by gross domestic product (at purchasing power parity) per capita, i.e. the purchasing power parity (PPP) value of all final goods and services produced within a country in a given year, divided by the average (or mid-year) population for the same year.

International Women's Day

International Women's Day (IWD), originally called International Working Women's Day, is celebrated on March 8 every year. In different regions the focus of the celebrations ranges from general celebration of respect, appreciation, and love towards women for their economic, political, and social achievements. Started as a Socialist political event, the holiday blended the culture of many countries, primarily in Europe, especially those in the Soviet Bloc. In some regions, the day lost its political flavor, and became simply an occasion for people to express their love for women in a way somewhat similar to a mixture of Mother's Day and Valentine's Day. In other regions, however, the political and human rights theme designated by the United Nations runs strong, and political and social awareness of the struggles of women worldwide are brought out and examined in a hopeful manner. Some people celebrate the day by wearing purple ribbons.

The earliest Women’s Day observance was held on February 28, 1909, in New York; it was organized by the Socialist Party of America in remembrance of the 1908 strike of the International Ladies' Garment Workers' Union. There was no specific strike happening on March 8, despite later claims.

In August 1910, an International Women's Conference was organized to precede the general meeting of the Socialist Second International in Copenhagen, Denmark. Inspired in part by the American socialists, German Socialist Luise Zietz proposed the establishment of an annual 'International Woman's Day' (singular) and was seconded by fellow socialist and later communist leader Clara Zetkin, although no date was specified at that conference. Delegates (100 women from 17 countries) agreed with the idea as a strategy to promote equal rights, including suffrage, for women. The following year, on March 19, 1911, IWD was marked for the first time, by over a million people in Austria, Denmark, Germany and Switzerland. In the Austro-Hungarian Empire alone, there were 300 demonstrations. In Vienna, women paraded on the Ringstrasse and carried banners honouring the martyrs of the Paris Commune. Women demanded that women be given the right to vote and to hold public office. They also protested against employment sex discrimination. Americans continued to celebrate National Women's Day on the last Sunday in February.

Female members of the Australian Builders Labourers Federation march on International Women's Day 1975 in Sydney
In 1913 Russian women observed their first International Women's Day on the last Saturday in February (by Julian calendar then used in Russia).

Although there were some women-led strikes, marches, and other protests in the years leading up to 1914, none of them happened on March 8. In 1914 International Women's Day was held on March 8, possibly because that day was a Sunday, and now it is always held on March 8 in all countries. The 1914 observance of the Day in Germany was dedicated to women's right to vote, which German women did not win until 1918.

In London there was a march from Bow to Trafalgar Square in support of women's suffrage on 8 March 1914. Sylvia Pankhurst was arrested in front of Charing Cross station on her way to speak in Trafalgar Square.

In 1917 demonstrations marking International Women's Day in Saint Petersburg on the last Thursday in February (which fell on March 8 on the Gregorian calendar) initiated the February Revolution. Women in Saint Petersburg went on strike that day for “Bread and Peace" – demanding the end of World War I, an end to Russian food shortages, and the end of czarism. Leon Trotsky wrote, "23 February (8th March) was International Woman’s Day and meetings and actions were foreseen. But we did not imagine that this ‘Women’s Day’ would inaugurate the revolution. Revolutionary actions were foreseen but without date. But in morning, despite the orders to the contrary, textile workers left their work in several factories and sent delegates to ask for support of the strike… which led to mass strike... all went out into the streets."

Following the October Revolution, the Bolshevik Alexandra Kollontai and Vladimir Lenin made it an official holiday in the Soviet Union, and it was established, but was a working day until 1965. On May 8th, 1965 by the decree of the USSR Presidium of the Supreme Soviet International Women's Day was declared a non-working day in the USSR "in commemoration of the outstanding merits of Soviet women in communistic construction, in the defense of their Fatherland during the Great Patriotic War, in their heroism and selflessness at the front and in the rear, and also marking the great contribution of women to strengthening friendship between peoples, and the struggle for peace. But still, women's day must be celebrated as are other holidays."

From its official adoption in Russia following the Soviet Revolution in 1917 the holiday was predominantly celebrated in communist and socialist countries. It was celebrated by the communists in China from 1922, and by Spanish communists from 1936. After the founding of the People's Republic of China on October 1, 1949 the state council proclaimed on December 23 that March 8 would be made an official holiday with women in China given a half-day off.

In the West, International Women's Day was first observed as a popular event after 1977 when the United Nations General Assembly invited member states to proclaim March 8 as the UN Day for women's rights and world peace. But women of Eastern European origins in North America were celebrating International Women's Day decades earlier than that. During World War II, some Western countries marked the date with an emphasis on women's contributions to the war effort and to the defeat of Fascism. Eleanor Roosevelt praised such celebrations of women's worldwide unity in her "My Day" column in 1944.

Didgeridoo

The didgeridoo (also known as a didjeridu) is a wind instrument developed by Indigenous Australians of northern Australia potentially within the last 1,500 years and still in widespread use today both in Australia and around the world. It is sometimes described as a natural wooden trumpet or "drone pipe". Musicologists classify it as a brass aerophone.

There are no reliable sources stating the didgeridoo's exact age. Archaeological studies of rock art in Northern Australia suggest that the people of the Kakadu region of the Northern Territory have been using the didgeridoo for less than 1,000 years, based on the dating of paintings on cave walls and shelters from this period. A clear rock painting in Ginga Wardelirrhmeng, on the northern edge of the Arnhem Land plateau, from the freshwater period (that was begun 1500 years ago) shows a didgeridoo player and two songmen participating in an Ubarr Ceremony.

A modern didgeridoo is usually cylindrical or conical, and can measure anywhere from 1 to 3 m (3 to 10 ft) long. Most are around 1.2 m (4 ft) long. Generally, the longer the instrument, the lower its pitch or key. However, flared instruments play a higher pitch than unflared instruments of the same length.

There are numerous names for the instrument among the Aboriginal peoples of northern Australia, none of which closely resemble the word "didgeridoo". Many didgeridoo enthusiasts and some scholars advocate reserving local names for traditional instruments, and this practice has been endorsed by some Aboriginal community organisations. However, in everyday conversation, bilingual Aboriginal people will often use the word "didgeridoo" interchangeably with the instrument's name in their own language.

"Didgeridoo" is considered to be an onomatopoetic word of Western invention. The earliest occurrences of the word in print include a 1919 issue of Smith's Weekly where it was referred to as an "infernal didjerry" which "produced but one sound – (phonic) didjerry, didjerry, didjerry and so on ad infinitum", the 1919 Australian National Dictionary, The Bulletin in 1924 and the writings of Herbert Basedow in 1926.

A rival explanation, that didgeridoo is a corruption of the Irish language (Gaelic) phrase dúdaire dubh or dúidire dúth, is controversial. Dúdaire/dúidire is a noun that may mean, depending on the context, "trumpeter", "hummer", "crooner", "long-necked person", "puffer", "eavesdropper", or "chain smoker", while dubh means "black" and dúth means "native".

Yiḏaki (sometimes spelt yirdaki) is one of the most commonly used names, although – strictly speaking – it refers to a specific type of instrument made and used by the Yolngu people of north-east Arnhem Land. However, since the passing, in early 2011, of a Manggalili-clan man whose name sounds similar to yiḏaki, Yolngu themselves now use the synonym mandapul to refer to the instrument, out of respect for the deceased.

There are numerous other, regional names for the didgeridoo. The following are some of the more common of these.

Authentic Aboriginal didgeridoos are produced in traditionally oriented communities in Northern Australia or by makers who travel to Central and Northern Australia to collect the raw materials. They are usually made from hardwoods, especially the various eucalyptus species that are endemic to the region. Generally the main trunk of the tree is harvested, though a substantial branch may be used instead. Aboriginal didgeridoo craftsmen hunt for suitably hollow live trees in areas with obvious termite activity. Termites attack these living eucalyptus trees, removing only the dead heartwood of the tree, as the living sapwood contains a chemical that repels the insects. Various techniques are employed to find trees with a suitable hollow, including knowledge of landscape and termite activity patterns, and a kind of tap or knock test, in which the bark of the tree is peeled back, and a fingernail or the blunt end of a tool, such as an axe is knocked against the wood to determine if the hollow produces the right resonance.

Once a suitably hollow tree is found, it is cut down and cleaned out, the bark is taken off, the ends trimmed, and the exterior is shaped; this results in a finished instrument. This instrument may be painted or left undecorated. A rim of beeswax may be applied to the mouthpiece end. Traditional instruments made by Aboriginal craftsmen in Arnhem Land are sometimes fitted with a "sugarbag" mouthpiece. This black beeswax comes from wild bees and has a distinctive aroma.

Non-traditional didgeridoos can also be made from PVC piping, non-native hard woods (typically split, hollowed and rejoined), glass, fiberglass, metal, agave, clay, hemp (in the form of a bioplastic named zelfo), and even carbon fibre. These didges typically have an upper inside diameter of around 1.25" down to a bell end of anywhere between two to eight inches and have a length corresponding to the desired key. The mouthpiece can be constructed of beeswax, hardwood or simply sanded and sized by the craftsman. In PVC, an appropriately sized rubber stopper with a hole cut into it is equally acceptable, or to finely sand and buff the end of the pipe to create a comfortable mouthpiece.

Modern didgeridoo designs are distinct from the traditional Australian Aboriginal didgeridoo, and are innovations recognized by musicologists. Didgeridoo design innovation started in the late 20th century using non-traditional materials and non-traditional shapes.

Colossus of Rhodes

The Colossus of Rhodes was a statue of the Greek titan-god of the sun Helios, erected in the city of Rhodes, on the Greek island of the same name, by Chares of Lindos in 280 BC. One of the Seven Wonders of the Ancient World, it was constructed to celebrate Rhodes' victory over the ruler of Cyprus, Antigonus I Monophthalmus, whose son unsuccessfully besieged Rhodes in 305 BC. Before its destruction in the earthquake of 226 BC, the Colossus of Rhodes stood over 30 metres (98 feet) high, making it one of the tallest statues of the ancient world.

Construction began in 292 BC. Ancient accounts, which differ to some degree, describe the structure as being built with iron tie bars to which brass plates were fixed to form the skin. The interior of the structure, which stood on a 15-metre (49-foot) high white marble pedestal near the Mandraki harbour entrance, was then filled with stone blocks as construction progressed. Other sources place the Colossus on a breakwater in the harbour. The statue itself was over 30 metres (98 feet) tall. Much of the iron and bronze was reforged from the various weapons Demetrius's army left behind, and the abandoned second siege tower may have been used for scaffolding around the lower levels during construction. Upper portions were built with the use of a large earthen ramp. During the building, workers would pile mounds of earth on the sides of the colossus. Upon completion all of the earth was removed and the colossus was left to stand alone. After twelve years, in 280 BC, the statue was completed. Preserved in Greek anthologies of poetry is what is believed to be the genuine dedication text for the Colossus.

Construction

The Colossus of Rhodes as imagined in a 16th-century engraving by Martin Heemskerck, part of his series of the Seven Wonders of the World.
To you, O Sun, the people of Dorian Rhodes set up this bronze statue reaching to Olympus, when they had pacified the waves of war and crowned their city with the spoils taken from the enemy. Not only over the seas but also on land did they kindle the lovely torch of freedom and independence. For to the descendants of Herakles belongs dominion over sea and land.

Modern engineers have put forward a plausible hypothesis for the statue construction, based on the technology of those days (which was not based on the modern principles of earthquake engineering), and the accounts of Philo and Pliny who both saw and described the remains.

The base pedestal was at least 60 feet (18 m) in diameter and either circular or octagonal. The feet were carved in stone and covered with thin bronze plates riveted together. Eight forged iron bars set in a radiating horizontal position formed the ankles and turned up to follow the lines of the legs while becoming progressively smaller. Individually cast curved bronze plates 60 inches (1,500 mm) square with turned-in edges were joined together by rivets through holes formed during casting to form a series of rings. The lower plates were 1 inch (25 mm) in thickness to the knee and 3/4 inch thick from knee to abdomen, while the upper plates were 1/4 to 1/2 inch thick except where additional strength was required at joints such as the shoulder, neck, etc.

Destruction

The statue stood for 54 years until Rhodes was hit by the 226 BC earthquake, when significant damage was also done to large portions of the city, including the harbour and commercial buildings, which were destroyed. The statue snapped at the knees and fell over onto the land. Ptolemy III offered to pay for the reconstruction of the statue, but the oracle of Delphi made the Rhodians afraid that they had offended Helios, and they declined to rebuild it.

The remains lay on the ground as described by Strabo (xiv.2.5) for over 800 years, and even broken, they were so impressive that many travelled to see them. Pliny the Elder remarked that few people could wrap their arms around the fallen thumb and that each of its fingers was larger than most statues.

In 653, an Arab force under Muslim caliph Muawiyah I captured Rhodes, and according to The Chronicle of Theophanes the Confessor, the statue was cast down and sold to a Jewish merchant of Edessa who loaded the bronze on 900 camels. The Arab destruction and the purported sale to a Jew possibly originated as a powerful metaphor for Nebuchadnezzar's dream of the destruction of a great statue.

Bali

Bali is an island and province of Indonesia. The province includes the island of Bali and a few smaller neighbouring islands, notably Nusa Penida, Nusa Lembongan, and Nusa Ceningan. It is located at the westernmost end of the Lesser Sunda Islands, between Java to the west and Lombok to the east. Its capital of Denpasar is located at the southern part of the island.

With a population of 3,890,757 in the 2010 census, and 4,225,000 as of January 2014, the island is home to most of Indonesia's Hindu minority. According to the 2010 Census, 83.5% of Bali's population adhered to Balinese Hinduism, followed by 13.4% Muslim, Christianity at 2.5%, and Buddhism 0.5%.

Bali is a popular tourist destination, which has seen a significant rise in tourists since the 1980s. It is renowned for its highly developed arts, including traditional and modern dance, sculpture, painting, leather, metalworking, and music. The Indonesian International Film Festival is held every year in Bali.

Bali is part of the Coral Triangle, the area with the highest biodiversity of marine species. In this area alone over 500 reef building coral species can be found. For comparison, this is about 7 times as many as in the entire Caribbean. There is a wide range of dive sites with high quality reefs, all with their own specific attractions. Many sites can have strong currents and swell, so diving without a knowledgeable guide is inadvisable. Most recently, Bali was the host of the 2011 ASEAN Summit, 2013 APEC and Miss World 2013.

The island of Bali lies 3.2 km (2 mi) east of Java, and is approximately 8 degrees south of the equator. Bali and Java are separated by the Bali Strait. East to west, the island is approximately 153 km (95 mi) wide and spans approximately 112 km (69 mi) north to south; administratively it covers 5,780 km2, or 5,577 km2 without Nusa Penida District, its population density is roughly 750 people/km2.

Bali's central mountains include several peaks over 3,000 metres (9,800 feet) in elevation. The highest is Mount Agung (3,031 m (9,944 ft)), known as the "mother mountain" which is an active volcano rated as one of the world's most likely sites for a massive eruption within the next 100 years. Mountains range from centre to the eastern side, with Mount Agung the easternmost peak. Bali's volcanic nature has contributed to its exceptional fertility and its tall mountain ranges provide the high rainfall that supports the highly productive agriculture sector. South of the mountains is a broad, steadily descending area where most of Bali's large rice crop is grown. The northern side of the mountains slopes more steeply to the sea and is the main coffee producing area of the island, along with rice, vegetables and cattle. The longest river, Ayung River, flows approximately 75 km.

The island is surrounded by coral reefs. Beaches in the south tend to have white sand while those in the north and west have black sand. Bali has no major waterways, although the Ho River is navigable by small sampan boats. Black sand beaches between Pasut and Klatingdukuh are being developed for tourism, but apart from the seaside temple of Tanah Lot, they are not yet used for significant tourism.

Subak irrigation system
The largest city is the provincial capital, Denpasar, near the southern coast. Its population is around 491,500 (2002). Bali's second-largest city is the old colonial capital, Singaraja, which is located on the north coast and is home to around 100,000 people. Other important cities include the beach resort, Kuta, which is practically part of Denpasar's urban area, and Ubud, situated at the north of Denpasar, is the island's cultural centre.

Three small islands lie to the immediate south east and all are administratively part of the Klungkung regency of Bali: Nusa Penida, Nusa Lembongan and Nusa Ceningan. These islands are separated from Bali by the Badung Strait.

To the east, the Lombok Strait separates Bali from Lombok and marks the biogeographical division between the fauna of the Indomalayan ecozone and the distinctly different fauna of Australasia. The transition is known as the Wallace Line, named after Alfred Russel Wallace, who first proposed a transition zone between these two major biomes. When sea levels dropped during the Pleistocene ice age, Bali was connected to Java and Sumatra and to the mainland of Asia and shared the Asian fauna, but the deep water of the Lombok Strait continued to keep Lombok Island and the Lesser Sunda archipelago isolated.

Kalahari Desert

The Kalahari Desert (in Afrikaans: Kalahari-woestyn) is a large semi-arid sandy savannah in southern Africa extending 900,000 square kilometres (350,000 sq mi), covering much of Botswana, parts of Namibia, and regions of South Africa. A semi-desert, with huge tracts of excellent grazing after good rains, the Kalahari supports more animals and plants than a true desert, such as the Namib Desert to the west. There are small amounts of rainfall and the summer temperature is very high. The driest areas usually receive 110–200 millimetres of rain per year, and the wettest just a little over 500 millimetres (20 in). The surrounding Kalahari Basin covers over 2,500,000 square kilometres (970,000 sq mi) extending farther into Botswana, Namibia and South Africa, and encroaching into parts of Angola, Zambia and Zimbabwe. The Kalahari is home to many migratory birds and animals. Previously havens for wild animals from elephants to giraffes, and for predators such as lions and cheetahs, the riverbeds are now mostly grazing spots, though leopards and cheetahs can still be found. The area is now heavily grazed and cattle fences restrict the movement of wildlife. Among deserts of the Southern Hemisphere, the Kalahari most closely resembles some Australian deserts in its latitude and its mode of formation. The Kalahari Desert came into existence approximately sixty million years ago along with the formation of the African continent.

Derived from the Tswana word Kgala, meaning "the great thirst", or Kgalagadi, meaning "a waterless place", the Kalahari has vast areas covered by red sand without any permanent surface water. Drainage is by dry valleys, seasonally inundated pans, and the large salt pans of the Makgadikgadi Pan in Botswana and Etosha Pan in Namibia. The only permanent river, the Okavango, flows into a delta in the northwest, forming marshes that are rich in wildlife. Ancient dry riverbeds—called omuramba—traverse the central northern reaches of the Kalahari and provide standing pools of water during the rainy season.

Despite its aridity, the Kalahari supports a variety of flora. The native flora includes acacia trees and many other herbs and grasses. The kiwano fruit, also known as the horned melon, melano, African horned cucumber, jelly melon, or hedged gourd, is endemic to a region in the Kalahari Desert (specific region unknown).

Even where the Kalahari "desert" is dry enough to qualify as a desert in the sense of having low precipitation, it is not strictly speaking a desert because it has too dense a ground cover. The main region that lacks ground cover is in the southwest Kalahari (southeast of Namibia, northwest of South Africa and southwest of Botswana) in the south of the Kgalagadi Transfrontier Park. For instance in the ZF Mgcawu District Municipality of South Africa, total vegetation cover may be as low as 30.72% on non-protected (from cattle grazing) farmlands south of Twee Rivieren Rest Camp and 37.74% in the protected (from cattle grazing) South African side of the Kgalagadi Transfrontier Park: these southernmost Kalahari xeric savanna areas are truly semi-deserts. However, in all the remaining Kalahari, except on salt pans during the dry season, the vegetation cover can be clearly denser, up to almost 100% in some limited areas.

In an area of about 600,000 km2 in the south and west of the Kalahari, the vegetation is mainly xeric savanna. This area is the ecoregion identified by World Wide Fund for Nature as Kalahari xeric savanna. Typical savanna grasses include (Schmidtia, Stipagrostis, Aristida, and Eragrostis) interspersed with trees such as camelthorn (Acacia erioloba), grey camelthorn (Acacia haematoxylon), shepherd’s tree (Boscia albitrunca), blackthorn (Acacia mellifera), and silver cluster-leaf (Terminalia sericea).

In certain areas where the climate is drier, it becomes a true semi-desert with ground not entirely covered by vegetation: "open" as opposed to "closed" vegetation. Examples include the north of the Siyanda District, itself in the north of South Africa, and the Keetmanshoop Rural in the southeast of Namibia. In the north and east, there are dry forests covering an area of over 300,000 km2 in which Rhodesian teak and several species of acaciaare prominent.

Outside the Kalahari "desert", but in the Kalahari basin, a halophytic vegetation to the north is adapted to pans, lakes that are completely dry during the dry season, and maybe for years during droughts, such as in Etosha and Makgadikgadi

A totally different vegetation is adapted to the perennial fresh water of the Okavango Delta, an ecoregion termed.

Most profitable programming languages

1.    SQL

It’s no surprise SQL (pronounced ‘sequel’) tops the job list since it can be found far and wide in various flavors. Database technologies such as MySQL, PostgreSQL and Microsoft SQL Server power big businesses, small businesses, hospitals, banks, universities. Indeed, just about every computer and person with access to technology eventually touches something SQL. For instance, all Android phones and iPhones have access to a SQL database called SQLite and many mobile apps developed Google, Skype and DropBox use it directly.

2.    Java

The tech community recently celebrated the 20th anniversary of Java. It’s one of the most widely adopted programming languages, used by some 9 million developers and running on 7 billion devices worldwide. It’s also the programming language used to develop all native Android apps. Java’s popularity with developers is due to the fact that the language is grounded in readability and simplicity. Java has staying power since it has long-term compatibility, which makes sure older applications continue to work now into the future. It’s not going anywhere anytime soon and is used to power company websites like LinkedIn.com, Netflix.com and Amazon.com.

3.    JavaScript

JavaScript – not to be confused with Java – is another one of the world’s most popular and powerful programming languages, and is used to spice up web pages by making them interactive. For example, JavaScript can be used to add effects to web pages, display pop-up messages or to create games with basic functionality. It’s also worth noting that JavaScript is the scripting language of the World Wide Web and is built right into all major web browsers including Internet Explorer, FireFox and Safari. Almost every website incorporates some element of JavaScript to add to the user experience, adding to the demand for JavaScript developers. In recent years JavaScript has also gained use as the foundation of Node.js, a server technology that among other things enables real-time communication.  

4.    C#

Dating from 2000, C# (pronounced C-sharp) is a relatively new programming language designed by Microsoft for a wide range of enterprise applications that run on the .NET Framework. An evolution of C and  C++, the C# language is simple, modern, type safe and object oriented.

5.    C++

C++ (pronounced C-plus-plus) is a general purpose object-oriented programming language based on the earlier ‘C’ language. Developed by Bjarne Stroustrup at Bell Labs, C++ was first released in 1983. Stroustrup keeps an extensive list of applications written in C++. The list includes Adobe and Microsoft applications, MongoDB databases, large portions of Mac OS/X and is the best language to learn for performance-critical applications such as “twitch” game development or audio/video processing.

6.    Python

Python is a general purpose programming language that was named after the Monty Python (so you know it’s fun to work with)! Python is simple and incredibly readable since closely resembles the English language. It’s a great language for beginners, all the way up to seasoned professionals. Python recently bumped Java as the language of choice inintroductory programming courses with eight of the top 10 computer science departments now using Python to teach coding, as well as 27 of the top 39 schools. Because of Python’s use in the educational realm, there are a lot of libraries created for Python related to mathematics, physics and natural processing. PBS, NASA and Reddit use Python for their websites.

7.     PHP

Created by Danish-Canadian programmer Rasmus Lerdorf in 1994, PHP was never actually intended to be a new programming language. Instead, it was created to be a set of tools to help Rasmus maintain his Personal Home Page (PHP). Today, PHP (Hypertext Pre-Processor) is a scripting language, running on the server, which can be used to create web pages written in HTML. PHP tends to be a popular languages since its easy-to use by new programmers, but also offers tons of advanced features for more experienced programmers.9.   

8.    iOS/Swift

In 2014, Apple decided to invent their own programming language. The result was Swift – a new programming language for iOS and OS X developers to create their next killer app. Developers will find that many parts of Swift are familiar from their experience of developing in C++ and Objective-C. Companies including American Airlines, LinkedIn, and Duolingo have been quick to adopt Swift, and we’ll see this language on the rise in the coming years.

Any great craftsman has a belt full of tools, each a perfect choice for certain situations. Similarly, there will never be just a single programming language, and each language will evolve and improve over time to keep pace with innovation.

9.    Ruby on Rails

Like Java or the C language, Ruby is a general purpose programming language, though it is best known for its use in web programming, and Rails serves as a framework for the Ruby Language. Ruby on Rails has many positive qualities including rapid development, you don’t need as much code, and there are a wide variety of 3rd party libraries available. It’s used from companies ranging from small start-ups to large enterprises and everything in-between. Hulu, Twitter, Github and Living Social are using Ruby on Rails for at least one of their web applications.

Komodo dragon

The Komodo dragon, also known as the Komodo monitor, is a large species of lizard found in the Indonesian islands of Komodo, Rinca, Flores, Gili Motang, and Padar. A member of the monitor lizard family Varanidae, it is the largest living species of lizard, growing to a maximum length of 3 metres (10 ft) in rare cases and weighing up to approximately 70 kilograms (150 lb). Their unusually large size has been attributed to island gigantism, since no other carnivorous animals fill the niche on the islands where they live. However, recent research suggests the large size of Komodo dragons may be better understood as representative of a relict population of very large varanid lizards that once lived across Indonesia and Australia, most of which, along with other megafauna, died out after the Pleistocene. Fossils very similar to V. komodoensis have been found in Australia dating to greater than 3.8 million years ago, and its body size remained stable on Flores, one of the handful of Indonesian islands where it is currently found, over the last 900,000 years, "a time marked by major faunal turnovers, extinction of the island's megafauna, and the arrival of early hominids by 880 ka ." As a result of their size, these lizards dominate the ecosystems in which they live. Komodo dragons hunt and ambush prey including invertebrates, birds, and mammals. It has been claimed that they have a venomous bite; there are two glands in the lower jaw which secrete several toxic proteins. The biological significance of these proteins is disputed, but the glands have been shown to secrete an anticoagulant. Komodo dragon group behaviour in hunting is exceptional in the reptile world. The diet of big Komodo dragons mainly consists of deer, though they also eat considerable amounts of carrion. Komodo dragons also occasionally attack humans in the area of West Manggarai Regency where they live in Indonesia. Mating begins between May and August, and the eggs are laid in September. About 20 eggs are deposited in abandoned megapode nests or in a self-dug nesting hole. The eggs are incubated for seven to eight months, hatching in April, when insects are most plentiful. Young Komodo dragons are vulnerable and therefore dwell in trees, safe from predators and cannibalistic adults. They take 8 to 9 years to mature, and are estimated to live up to 30 years. Komodo dragons were first recorded by Western scientists in 1910. Their large size and fearsome reputation make them popular zoo exhibits. In the wild, their range has contracted due to human activities, and they are listed as vulnerable by the IUCN. They are protected under Indonesian law, and a national park, Komodo National Park, was founded to aid protection efforts.