Category Worls And Its People

What is the basic structure of wealth and poverty in various parts of world?

Some nations in the world are rich, while others are very poor. The gap between them seems to grow ever wider. Measured by the average income earned by people in the richest and poorest fifth of the world’s nations, the gap has grown from 30 to 1 in 1960 to nearly 80 to 1 today. Within both rich and poor countries, there are also great contrasts in wealth.

The wealthiest countries are those that have developed industries and services which can supply their own populations with all their needs. They do this either by producing these products and services themselves, or by importing them from other countries, paying for them by exporting goods. In poorer developing countries, people may produce only enough food to feed their families. Disease and climatic disaster may prevent even this.

The population of developing nations has grown greatly in recent years. Their high birth rates means even more mouths to feed.

South America has some of the fastest-growing cities in the world. They include the Brazilian super cities of Sao Paulo and Rio de Janeiro, both with populations of more than 10 million. People from the countryside flock to these cities to find work but there is nowhere for them to live. They build their own shantytowns (locally known as favelas) just outside the city by building shelters and shacks from any material that comes to hand. People who live in shantytowns cannot find work easily and so they are forced to work for very low wages.

The wealth of a nation can be measured by its gross domestic product (GDP).This is defined as the value of all the goods and services produced there, including those produced by foreign-owned firms. The Group of Seven (G7) are the seven leading industrial nations of the world. These nations – the United States, Japan, Germany, France, the United Kingdom, Italy and Canada – account for more than 60% of the world’s GDP. The country with the highest GDP per person in 1996 was Switzerland ($46,000). In the same year, the figure for Rwanda in Africa was $100. More than 1.3 billion people around the world live on less than one dollar a day.

Wealthy nations such as the G7 lend money to developing countries. However, the developing countries often find that, because of their low GDP, they cannot repay the loans and a big debt burden builds up. The largest foreign aid donor in 1996 was Japan with aid amounting to more than $15,000 million.

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What are the famous bridges in the world?

Bridges have been used since ancient times to span deep ravines, rivers and other stretches of water. Early bridges were made of wood which rotted easily and could not span great distances. In some parts of the world, people made bridges from wood and rope. They had walkways made of wooden slats and rope handrails. Bridges made of stone may last for centuries. However, stone is heavy to transport and long bridges need to have many sturdy supports.

During the Industrial Revolution, which began in the 18th century, engineers began to build bridges made from iron. These were much more durable than wooden bridges and could span longer distances than stone ones. The first iron bridge was built at Coalbrookdale, England, in 1779.

Modern bridges are built using steel and concrete. They may carry roads or railways over rivers, wide estuaries or high valleys, or above other roads and railways. There are a number of different kinds of bridge design available, each of which may be used in a modern bridge according to the type of crossing required.

A beam bridge is one of the simplest and oldest designs. The beam is supported at each end. The earliest bridges were tree trunks or stone slabs laid across a stream supported by the banks on either side. A clapper bridge is a type of Beam Bridge which is supported from beneath by several columns in the river bed or ground. The deck may be flat or made from a hollow girder (truss) containing the road or railway.

An arch bridge—a very strong type—has a deck supported on an arch fixed to the banks. Some arch bridges are too low for river traffic to pass underneath so a part of their span may be a bascule or lift bridge.

This can be raised in the middle like a drawbridge so that ships can pass through.

A cantilever is a beam or structure that is fixed at one end only. Cantilever bridges are built in two halves, with each beam cantilevered out from the bank and each half balanced on a support in the river. There may be a short central span where the two halves meet.

Suspension bridges can span long distances. The towers of the bridge are built first and long steel cables are suspended from the towers. Lengths of cable called hangers are fixed to the suspending cables. The deck of the bridge is lifted into position and attached to the hangers. Suspension bridges are ideal for long, high spans as they do not require a row of supporting columns that may interfere with river transport. One of the most famous examples of a suspension bridge is the Golden Gate Bridge (1280 metres), near San Francisco in the USA, which was completed in 1937.

A cable-stayed bridge has diagonal steel cables running from high supporting masts at either end connected to the deck of the bridge. The weight of the deck is supported by the masts.

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Which types of buildings are called Skyscrapers?

Skyscrapers are very tall buildings, usually more than 20 storeys high. Their weight is supported by a steel frame rather than outside walls. They are a feature of many large cities, especially in North America and East Asia, where the high price of land leads developers to build tall, thin buildings that occupy the minimum amount of land space, rather than low-rise, sprawling ones.

The first skyscraper, the Home Insurance Building, was built in Chicago in 1884 following a fire that devastated the city. Soon, skyscrapers started to appear in New York as well as Chicago, often being built higher and higher in competition with one another. In recent years, Japan, Malaysia and China are among nations that have joined the race to build the world’s tallest buildings.

The John Hancock Center in Chicago, USA, was completed in 1968. A skyscraper with both offices and residential apartments; it is the tallest multi-purpose building in the world and the seventh tallest skyscraper of all. It is 344 metres high but its twin antennae add a further 105 metres, making it a total of nearly 450 metres. It has a hull and core construction—a strong central concrete core with an open space between it and the steel frame. The frame has a triangular grid to give the structure maximum strength.

The John Hancock Center is like a city in a tower. It has shops, a bank, a post office, a restaurant, a swimming pool and a fitness centre. There are 50 lifts (it takes only 39 seconds to ascend to the 94th floor). A car park with spaces for 1200 cars takes up the first seven floors. Cars drive up a spiral ramp to get to it.

The building has more than 2000 kilometres of electric wiring, carrying enough electricity to supply the equivalent of a city of 30,000 people. More than 2.75 million litres of water are consumed each day. Computers warn of any fault in the skyscraper’s service systems.

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What are various types of construction of Building around the world?

People have constructed buildings from ancient times as homes to provide shelter, monuments or places of worship. Earth, wood and stone have always been used as building materials. Bricks, hardened clay, were first used in the Middle East in about 3000 BC. Concrete is made by mixing sand, cement and water. Reinforced concrete dates from the late 1800s. Often used in modern buildings, it contains steel wires or rods to provide extra strength.

Buildings belong to one of two types. The first type has solid walls, called load-bearing walls that support the floors and roof of the building. The second type has a framework of wood, steel or concrete that bears the weight of the building.

Most buildings need foundations (a solid base) to prevent them from sinking into the ground or falling over. Foundations can be footings (underground walls), flat rafts, or underground supporting pillars called piles that are driven into the ground.

TALL STRUCTURES

The Great Pyramid at Giza in Egypt was the world’s tallest structure for nearly 4000 years, until the great age of cathedral building began in medieval Europe. Lincoln Cathedral in England, which was built in 1311, had a great spire that made it slightly taller than the pyramid, although it was blown down in a storm in 1549. The Washington Monument in Washington, USA, became the world’s tallest structure in 1884, before the Eiffel Tower in Paris, France, almost doubled the record five years later. The skyscrapers of the 20th century claimed the honour until the CN Tower, still the world’s tallest self-supporting structure, was built in Toronto in 1976.

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What are various Ports and Water ways?

Even though aircraft now carry many of the world’s passengers, shipping is still a vital link between countries, particularly for carrying cargo. The biggest vessels are called bulk carriers. They include oil supertankers, some of which are more than 450 metres long. Container ships carry general cargo stored in large steel boxes stacked up like building blocks. These can be unloaded directly on to trucks.

The River Rhine rises in Switzerland and runs along the border between France and Germany, then on through Germany and the Netherlands, meeting the North Sea near Rotterdam. It is one of Europe’s most important industrial waterways. As well as barges carrying cargo, river boats take tourists along the river to see the vineyards and ancient castles on its banks.

Ships cross the oceans on fixed routes called shipping lanes. The world’s busiest shipping lanes link Europe and North America with the Middle East and East Asia. Ships go through the Suez and Panama Canals to shorten their journeys, although supertankers, being too large for the Suez Canal, still travel around the southern tip of Africa.

Modern cargo ships are much larger than vessels of the past, and big, efficient ports with docks (enclosed areas of water) are needed so that their cargoes can be loaded and unloaded as quickly as possible. Some ships take cargoes inland along large rivers and man-made waterways called canals.

Two major canals, cut through narrow necks of land, provide much shorter routes between ports. They are the 165-kilometre Suez Canal in Egypt, linking the Mediterranean Sea with the Red Sea, and the 82-kilometre Panama Canal, connecting the Atlantic and Pacific Oceans.

Canals often link natural waterways and provide a transport route across a continent. The Main-Danube Canal, for example, allows the movement of goods between Eastern and Western Europe. The United States and Canada have more than 41,000 kilometres of waterways linked to the St. Lawrence and Mississippi rivers and their tributaries. The St. Lawrence Seaway connects the Great Lakes, and the cities of Chicago, Detroit, Cleveland and Toronto among others, with the Atlantic Ocean.

Cargo on inland waterways in industrial countries, for example, the River Rhine in Germany, is usually carried by barges which are towed by tugs. Sometimes several barges are strapped together. Barges carry cargoes along the Rhine to and from the port of Rotterdam in the Netherlands, the world’s busiest port. Antwerp in Belgium is the largest inland port in the world. Even though it is 89 kilometres from the open sea, ships of all types load and unload cargoes there.

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Throw some light about air travel around the world?

Air travel has grown enormously since World War II. Until then, only the wealthy travelled by air. The development of the jet airliner in the 1950s made it possible for everyone to fly to destinations across the world.

The world’s busiest airport is O’Hare International near Chicago in the United States, with an average of one take-off or landing every 35 seconds and nearly 70 million passengers a year. Many of these flights are for people travelling within the United States – about 85 per cent of people travelling within the United States go by air. London’s Heathrow Airport handles more international traffic than any other airport with more than 55 million international passengers a year.

A large modern airport employs thousands of people. Air traffic controllers work in a control tower, directing all aircraft to and from runways and deciding when it is safe to take off or land. They have powerful radar equipment to keep watch over the whole airspace around the airport.

Baggage handlers load and unload suitcases from the aircraft. Once passengers have disembarked, ground crew prepares the aircraft to fly out again, and refuel it while firefighters stand by.

In the terminal, the passengers collect their baggage and go through customs, where officials check that they are not carrying drugs or goods which require import or export tax to be paid.

Airports also handle goods (air freight) that are required to be transported quickly. Warehouses store goods before loading and after arrival, when they are inspected by customs officials.

Security officers use X-ray equipment to check passengers for bombs, guns and other weapons. International passengers also have to pass through immigration where they show their passports and any visas that are required to enter the country. Officials often stamp the passport to show that passengers are entering the country legally. Airports also have lounges and restaurants where passengers can wait for their flights.

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