About 6 percent of Earth's surface is covered by swamps. Swamps are also filters for groundwater, and protect against flooding. Swamps are one of the key wetland areas which are protected by the international agency Ramsar.
Some well-known swamps are:
Peat accumulates in these swamps. Some of the world's largest swamps are found along major rivers such as the Amazon, the Mississippi, and the Congo.
Diego Rivera
Diego Rivera (December 8, 1886 – November 24, 1957) was a famous Mexican painter and muralist. He was born in Guanajuato City, Guanajuato.
Rivera is famous for his 1933 mural, "Man at the Crossroads," for the lobby of the RCA Building at Rockefeller Center. Before he finished the mural, people saw that there was an image of Vladimir Lenin and other communist images in it. Rivera was fired because of this and the mural was destroyed.
Rivera's wife, Frida Kahlo, was also a famous Mexican painter. He died in Mexico City of congestive heart failure at the age of 70.
Frida Kahlo
David Alfaro Siqueiros
David Alfaro Siqueiros (December 29, 1896 in Camargo, Chihuahua, Mexico – January 6, 1974 in Cuernavaca, Morelos, Mexico) was a famous painter and muralist.
Avenged Sevenfold
Avenged Sevenfold (or A7X) is an American hard rock band. The band started in Huntington Beach, California in 1999. The band is sometimes called "A7X", which is a title started by the band's guitarist, Zacky Vengeance. They have a song called "Beast and the Harlot" which is used in the video game "Guitar Hero II" and "". Their song "Almost Easy" is used in "Rock Band 2".
Siege
A siege is a military blockade of a city or fortress. The purpose is to conquer by starvation, lack of water, or by a well-prepared assault.
Siege warfare is a form of constant, low-intensity conflict. The defender inside has a strong, static, defensive position. Negotiation between combatants is common.
A siege happens when the attacker gets to a city or fortress which cannot be taken by storm, and which refuses to surrender. Sieges block the supplies and reinforcements or escape of men. Siege engines, artillery bombardment, and undermining are frequent. Deception and treachery are common.
Sieges can be decided by starvation, thirst, or disease. This form of siege can take many months or even years, depending upon the size of the stores of food the fortified position holds.
Well known sieges were:
Hull
A hull can be:
In mathematics:
Other places:
There are several people named Hull:
There is also:
River Hull
The River Hull is a river in Yorkshire in the north of England.
It has its source in the Yorkshire Wolds. It joins the River Humber estuary in the centre of Kingston upon Hull.
The river separates the industrial area of the city, and several opening bridges have been constructed. These continue to cause traffic delays during high tides, though river traffic is not so heavy any more in recent years.
These are the bridges in the Hull area:-
Hull (watercraft)
A hull is the body of a ship or boat. It is a central concept in floating vessels as it provides the buoyancy that keeps the vessel from sinking.
Almost all watercraft, from small boats to the largest ships, have a general form that is necessary for stability and efficient propulsion, which includes:
Archimedes, a Greek doctor, inventor, and mathematician, made the science of "hydrostatics", the study of liquids and pressure. The Archimedes principle says that the force holding up an object that is inside a liquid in part or totally. So, a ship actually does sink, until it moves an amount of water that is the same weight of the weight of the ship. The weight must be over a wide area to work. This explains why ships and boats (including submarines) float. An object's weight pulls down in the direction of gravity, but the water's buoyant (floating) force pushes it up. Because these forces counteract each other, the object seems to lose weight. NASA uses this principle to prepare their astronauts for the weightlessness of space, so they had the astronauts work on parts of the space ship inside water tanks 25 feet (7.6 m) deep.
Bow is the frontmost part of the hull
Stern is the rear-most part of the hull
Portside is the left side of the boat when facing the Bow
Starboard is the right side of the boat when facing the Bow
Waterline is an imaginary line circumscribing the hull that matches the surface of the water when the hull is not moving.
Midships is the midpoint of the LWL (see below).
It is half-way from the forwardmost point on the waterline to the rear-most point on the waterline.
Baseline an imaginary reference line used to measure vertical distances from. It is usually located at the bottom of the hull.
Hull forms are defined as follows:
Buoyancy
In physics, buoyancy () is a force on an object making that object rise or move upward. It comes from the Spanish word for "float", "boyar". Buoyancy is made by the difference in pressure put on the object by the Fluid or air that the object is in.
The net upward buoyancy force is equal to the magnitude of the weight of fluid that is displaced by the body. This force enables the object to float or at least to seem lighter. Buoyancy is important for many vehicles such as boats, ships, balloons, and blimps.
If the object has exactly the same density as the liquid, then its buoyancy is the same as its weight. It will not sink or float.
If the object has a higher average density than the liquid, then its buoyancy is less than its weight. It will sink. That is why pebbles do not float.
If the object has a lower average density than the liquid, then its buoyancy is greater than its weight. That is why, although a ship may be made of steel which is more dense than water, it floats because it encloses a volume of air and the resulting shape has an average density less than that of the water.
Asura
The Asura are a group of supernatural creatures in Hinduism and Buddhism.
In today's beliefs and assumptions, the Asuras are demons. But this was not always that way. The idea of the Asuras is very, very old, from long before the time people learned how to read and write. The Asuras only became demons after much time had passed. Buddhism also has Asuras. These are from Hinduism but have also changed a lot in their own way.
Some of the Asuras are very important, and have been worshiped for thousands of years. The most important of these are Varuna and Mitra. Varuna is the god of the ocean, which in olden times was thought to be flowing under the earth. So, Varuna came to be seen as god of the underworld. In ancient times, water was thought to be where wisdom came from. So Varuna is considered very wise, and he gives his wisdom to those who honor him. Varuna's closest companion is Mitra. Mitra mostly means "friend" in Hinduism, but it originally meant "promise". And so Mitra is the god of friendships and promises. He protects people who honor the truth and punishes those who tell lies. The "Mi-" in "Mitra" means "to tie tightly". Friendship and promises tie people to one another.
In Hinduism, the Asura (Sanskrit: असुर) are a group of creatures looking for more power, sometimes called demons. They went against the devas. The devas and asuras are the children of "Kashyapa".
Hinduism has many stories of Asuras and Devas fighting each other. Mostly they fight about who will get the best prayers from the worshipers.
In Hinduism the Asuras are said to be beings of moral and social things. Like truth and marriage. The Daevas are said to be beings of natural things. Like the sun and the rain. In Hinduism, the Asuras are said to be "older". And the daevas are said to be "younger". There are very many Asuras and Daevas. Two hundred years ago someone counted them and said there were over 2,000 Daevas and Asuras. So naturally not all Asuras are very important. But some names have been forgotten since then, and others have been added. This is why Hinduism is called a "living religion." It is changing all the time.