Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few invertebrates such as sponges, jellyfish, adult sea squirts and starfish do not have one, even if diffuse neural tissue is present. It is located in the head, usually close to the primary sensory organs for such senses as vision, hearing, balance, taste, and smell. The brain of a vertebrate is the most complex organ of its body. In a typical human the cerebral cortex (the largest part) is estimated to contain 15–33 billion neurons,  each connected by synapses to several thousand other neurons. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells.

From an evolutionary-biological point of view, the function of the brain is to exert centralized control over the other organs of the body. The brain acts on the rest of the body either by generating patterns of muscle activity or by driving secretion of chemicals called hormones. This centralized control allows rapid and coordinated responses to changes in the environment. Some basic types of responsiveness such as reflexes can be mediated by the spinal cord or peripheral ganglia, but sophisticated purposeful control of behaviour based on complex sensory input requires the information-integrating capabilities of a centralized brain.

From a philosophical point of view, what makes the brain special in comparison to other organs is that it forms the physical structure that generates the mind. As Hippocrates put it: "Men ought to know that from nothing else but the brain come joys, delights, laughter and sports, and sorrows, griefs, despondency, and lamentations."  In the early part of psychology, the mind was thought to be separate from the brain. However, after early scientists conducted experiments it was determined that the mind was a component of a functioning brain that expressed certain behaviours based on the external environment and the development of the organism. The mechanisms by which brain activity gives rise to consciousness and thought have been very challenging to understand: despite rapid scientific progress, much about how the brain works remains a mystery. The operations of individual brain cells are now understood in considerable detail, but the way they cooperate in ensembles of millions has been very difficult to decipher. The most promising approaches treat the brain as a biological computer, very different in mechanism from electronic computers, but similar in the sense that it acquires information from the surrounding world, stores it, and processes it in a variety of ways.

This article compares the properties of brains across the entire range of animal species, with the greatest attention to vertebrates. It deals with the human brain insofar as it shares the properties of other brains. The ways in which the human brain differs from other brains are covered in the human brain article. Several topics that might be covered here are instead covered there because much more can be said about them in a human context. The most important is brain disease and the effects of brain damage, covered in the human brain article because the most common diseases of the human brain either do not show up in other species, or else manifest themselves in different ways.

Eye Structure And Function

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Eye is like a camera. The external object is seen like the camera takes the picture of any object. Light enters the eye through a small hole called the pupil and is focused on the retina, which is like a camera film. Eye also has a focusing lens, which focuses images from different distances on the retina. The colored ring of the eye, the iris, controls the amount of light entering the eye. It closes when light is bright and opens when light is dim. A tough white sheet called sclera covers the outside of the eye. Front of this sheet (sclera) is transparent in order to allow the light to enter the eye, the cornea. Ciliary muscles in ciliary body control the focusing of lens automatically. Choroid forms the vascular layer of the eye supplying nutrition to the eye structures. Image formed on the retina is transmitted to brain by optic nerve. The image is finally perceived by brain. A jelly like substance called vitreous humor fill the space between lens and retina. The lens, iris and cornea are nourished by clear fluid, aqueous humor, formed by the ciliary body and fill the space between lens and cornea. This space is known as anterior chamber. The fluid flows from ciliary body to the pupil and is absorbed through the channels in the angle of anterior chamber. The delicate balance of aqueous production and absorption controls pressure within the eye.

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The Great Wall of China

The Great Wall of China is a series of fortifications running in general east to west through the entire northern part of China, which is made of stone, brick, tamped earth, wood, and other materials, built originally in part to protect the northern borders of the Chinese Empire or its prototypical states against intrusions by various nomadic groups or military incursions by various warlike peoples or forces. Several walls had already been begun to be built beginning around the 7th century BC, these, later joined together and made bigger, stronger, and unified are now collectively referred to as the Great Wall. Especially famous is the wall built between 220–206 BC by the first Emperor of China, Qin Shi Huang. Little of that wall remains. Since then, the Great Wall has on and off been rebuilt, maintained, enhanced; the majority of the existing wall was reconstructed during the Ming Dynasty.

Other purposes of the Great Wall have included allowing for border control practices, such as check points allowing for the various imperial governments of China to tariff goods transported along the Silk Road, to regulate or encourage trade (for example trade between horses and silk products), as well as generally to control immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watch towers, troop barracks, garrison stations, signalling capabilities through the means smoke or fire, and the fact that the path of the Great Wall also served as a transportation corridor.

The Great Wall stretches from Shanhaiguan in the east, to Lop Lake in the west, along an arc that roughly delineates the southern edge of Inner Mongolia. The most comprehensive archaeological survey, using advanced technologies, has concluded that all the walls measure 8,851.8 km (5,500.3 mi).  This is made up of 6,259.6 km (3,889.5 mi) sections of actual wall, 359.7 km (223.5 mi) of trenches and 2,232.5 km (1,387.2 mi) of natural defensive barriers such as hills and rivers.

A previously unknown section of the wall was discovered in Mongolia by British explorer William Lindesay. 

Babylon

Babylon  was an Akkadian city-state of ancient Mesopotamia, the remains of which are found in present-day Al Hillah, Babylon Province, Iraq, about 85 kilometres (55 mi) south of Baghdad. All that remains of the original ancient famed city of Babylon today is a mound, or tell, of broken mud-brick buildings and debris in the fertile Mesopotamian plain between the Tigris and Euphrates rivers. The city itself was built upon the Euphrates, and divided in equal parts along its left and right banks, with steep embankments to contain the river's seasonal floods.

Available historical resources suggest that Babylon was at first a small town which had sprung up by the beginning of the 3rd millennium BC. The town flourished and attained independence with the rise of the First Amorite Babylonian Dynasty in 1894 BC. Claiming to be the successor of the ancient Eridu, Babylon eclipsed Nippur as the "holy city" of Mesopotamia around the time an Amorite king named Hammurabi first created the short lived Babylonian Empire; this quickly dissolved upon his death and Babylon spent long periods under Assyrian, Kassite and Elamite domination. Babylon again became the seat of the Neo-Babylonian Empire from 612 to 539 BC which was founded by Chaldeans and whose last king was an Assyrian. The Hanging Gardens of Babylon were one of the Seven Wonders of the Ancient World. After the fall of Babylon it came under the rules of the Achaemenid, Seleucid, Parthian, Roman and Sassanid empires

Leaning Tower.

 At Malaysia :

The leaning tower of Teluk Intan is the Malaysia equivalent of the world famous Leaning Tower of Pisa in Italy. It is located in the centre of the town of Teluk Intan, Perak. The tower is slanted leftward, similar to the Tower of Pisa. It is 25.5 metres tall and, from the outside, looks like a 8 storey building, though inside it is actually divided into 3 storeys.

The tower is located in the center of a square surrounded by Jalan Pasar, Jalan Selat, Jalan Bandar and Jalan Ah Cheong.

At india :

The Leaning Temple of Huma is the only leaning temple in the world and the only one of its kind in India. It is located in Huma, a village situated on the bank of the Mahanadi, 23 km south of Sambalpur in the Indian state of Orissa. The temple is dedicated to the Hindu god Shiva.Nobody knows whether this structure is leaning by design or by default. One interesting fact is that while the edifice leans, the pinnacle of the temple is perpendicular to the ground.

At Abu Dhabi :

Capital Gate is a skyscraper in Abu Dhabi adjacent to the Abu Dhabi National Exhibition Centre designed with a striking lean. At 160 m (520 ft) and 35 stories, it is one of the tallest buildings in the city and features an 18-degree incline to the west . The owner and developer of Capital Gate is Abu Dhabi National Exhibitions Company. The tower (also known as the leaning tower of Abu Dhabi) is the focal point of the Capital Center, Abu Dhabi National Exhibition Centre master development.

Taj Mahal

Introduction Taj Mahal:

The Taj Mahal   is a white Marble mausoleum located in Agra, India. It was built by Mughal emperor Shah Jahan in memory of his third wife, Mumtaz Mahal. The Taj Mahal is widely recognized as the jewel of Muslim art in India and one of the universally admired masterpieces of the world's heritage.

Taj Mahal is the finest example of Mughal architecture, a style that combines elements from Persian, Turkish and Indian architectural styles.

In 1983, the Taj Mahal became a UNESCO World Heritage Site. While the white domed marble mausoleum is the most familiar component of the Taj Mahal, it is actually an integrated complex of structures. The construction began around 1632 and was completed around 1653, employing thousands of artisans and craftsmen.  The construction of the Taj Mahal was entrusted to a board of architects under imperial supervision, including Abd ul-Karim Ma'mur Khan, Makramat Khan, and Ustad Ahmad Lahauri. Lahauri  is generally considered to be the principal designer.

History:

Soon after the Taj Mahal's completion, Shah Jahan was deposed by his son Aurangzeb and put under house arrest at nearby Agra Fort. Upon Shah Jahan's death, Aurangzeb buried him in the mausoleum next to his wife.

By the late 19th century, parts of the buildings had fallen badly into disrepair. During the time of the Indian rebellion of 1857, the Taj Mahal was defaced by British soldiers and government officials, who chiselled out precious stones and lapis lazuli from its walls. At the end of the 19th century, British viceroy Lord Curzon ordered a sweeping restoration project, which was completed in 1908. He also commissioned the large lamp in the interior chamber, modelled after one in a Cairo mosque. During this time the garden was remodelled with British-style lawns that are still in place today. 

amazing of Taj Mahal.

Pyramid

The pyramid  is a structure whose outer surfaces are roughly triangular and converge to a single point at the top. The base of a pyramid can be trilateral, quadrilateral, or any polygon shape, meaning that a pyramid has at least three triangular surfaces (at least four faces including the base). The square pyramid, with square base and four triangular outer surfaces, is a common version.

A pyramid's design, with the majority of the weight closer to the ground,  and with the pyramiding on top means that less material higher up on the pyramid will be pushing down from above. This distribution of weight allowed early civilizations to create stable monumental structures.

Pyramids have been built by civilizations in many parts of the world. For thousands of years, the largest structures on Earth were pyramids—first the Red Pyramid in the Dashur Necropolis and then the Great Pyramid of Khufu, both of Egypt, the latter the only one of the Seven Wonders of the Ancient World still remaining. Khufu's Pyramid is built entirely of limestone, and is considered an architectural masterpiece. It contains around 1,300,000 blocks ranging in weight from 2.5 tonnes (5,500 lb) to 15 tonnes (33,000 lb) and is built on a square base with sides measuring about 230 m (755 ft), covering 13 acres. Its four sides face the four cardinal points precisely and it has an angle of 52 degrees. The original height of the Pyramid was 146.5 m (488 ft), but today it is only 137 m (455 ft) high, the 9 m (33 ft) that is missing is due to the theft of the fine quality limestone covering, or casing stones to build houses and Mosques in Cairo. It is still the tallest pyramid. The largest pyramid by volume is the Great Pyramid of Cholula, in the Mexican state of Puebla.

Amazon Rain force

Introduce of Amazon : 

The Amazon Rainforest   also known in English as Amazonia or the Amazon Jungle, is a moist broadleaf forest that covers most of the Amazon Basin of South America. This basin encompasses seven million square kilometres (1.7 billion acres), of which five and a half million square kilometres (1.4 billion acres) are covered by the rainforest. This region includes territory belonging to nine nations. The majority of the forest is contained within Brazil, with 60% of the rainforest, followed by Peru with 13%, Colombia with 10%, and with minor amounts in, Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana. States or departments in four nations contain "Amazonas" in their names. The Amazon represents over half of the planet's remaining rainforests, and it comprises the largest and most species-rich tract of tropical rainforest in the world.

History of Amazon :

The rainforest likely formed during the Eocene era. It appeared following a global reduction of tropical temperatures when the Atlantic Ocean had widened sufficiently to provide a warm, moist climate to the Amazon basin. The rain forest has been in existence for at least 55 million years, and most of the region remained free of savanna-type biomes at least until the current ice age, when the climate was drier and savanna more widespread.

Following the Cretaceous,Tertiary extinction event, the extinction of the dinosaurs and the wetter climate may have allowed the tropical rainforest to spread out across the continent. From 65–34 Mya, the rainforest extended as far south as 45°. Climate fluctuations during the last 34 million years have allowed savanna regions to expand into the tropics. During the Oligocene, for example, the rainforest spanned a relatively narrow band that lay mostly above latitude 15°N. It expanded again during the Middle Miocene, then retracted to a mostly inland formation at the last glacial maximum.  However, the rainforest still managed to thrive during these glacial periods, allowing for the survival and evolution of a broad diversity of species.

During the mid-Eocene, it is believed that the drainage basin of the Amazon was split along the middle of the continent by the Purus Arch. Water on the eastern side flowed toward the Atlantic, while to the west water flowed toward the Pacific across the Amazonas Basin. As the Andes Mountains rose, however, a large basin was created that enclosed a lake; now known as the Solimões Basin. Within the last 5–10 million years, this accumulating water broke through the Purus Arch, joining the easterly flow toward the Atlantic.

There is evidence that there have been significant changes in Amazon rainforest vegetation over the last 21,000 years through the Last Glacial Maximum (LGM) and subsequent deglaciation. Analyses of sediment deposits from Amazon basin paleolakes and from the Amazon Fan indicate that rainfall in the basin during the LGM was lower than for the present, and this was almost certainly associated with reduced moist tropical vegetation cover in the basin.  There is debate, however, over how extensive this reduction was. Some scientists argue that the rainforest was reduced to small, isolated refugia separated by open forest and grassland . other scientists argue that the rainforest remained largely intact but extended less far to the north, south, and east than is seen today.This debate has proved difficult to resolve because the practical limitations of working in the rainforest mean that data sampling is biased away from the center of the Amazon basin, and both explanations are reasonably well supported by the available data.

What is air?

Air is something can be felt, but cannot be seen or tested. On the earth, it is everywhere. Air contains a lot of gases, the major components being nitrogen and oxygen. Apart from the ordinary gases, air contains rare gases like neon, helium, krypton. Since air contains gases, which have mass and hence weight, it also has weight. This weight is felt by all things on the surface of the earth. This is know as atmospheres pressure.

What is an atom?

The world atom comes from the Greek language, which means not divisible. It was named thus because it was through that an atom is small possible particle of any substance. An atom is made up of electrons, proton, and neutron. Electron are particles that carry tiny negative charge of electricity. The proton is about 1,836 times as heavy as the electron and carries a positive charge of electricity . the neutron , still heavier , carries no electronic charge at all. All element are classified according to their atomic weight. These weight are very small. A single atom of hydrogen weirht only about one million-million-million-million-millionth of a gramma. In other words, in one gramma of hydrogen, there are about 6 followed by 23 zeroes of atoms. If we start counting them, and count one atom per second. It would take us ten thousand million years to count all the atoms in just one gramme of hydrogen.

What is monsoon?

In many parts of the world, expecially in eastern and southern asia, wind from sea cause heavy rains in a particular period. This period is referred to as monsoon. In country like India, monsoon start  from the month of june or july. During monsoon , winds containing a lot of water, below from the sea. These wind caused  heavy rains on land. In India, the majority of rainfall these place during monsoon.

How are various kind of clouds formed?

When the warm air, laden with moisture, rises into the sky, it cools down into water vapour. The excess moisture change into small drops of water or bits of ice and are formed at different height and temperature, no two clouds are alike. The highest clouds are called translucent cloud. They may be made of ice.

Why do the star shine?

The shine of the star is because of the fact that star is a ball of very hot gas, which shine by its own light. The twinkle of the star is caused by substance in the air between star and the earth. The unsteady air bends the light from the star and the then , it appears to twinkle. Our sun is also a star and is neither very big nor very bright. But still, the other star look smaller then it, because they are so distance from the earth. By studying the difference in the spectra of the star, the astronomers are able to know about the colour, the temperature and even the chemical composition of the star. 

Which is the brightest star in the sky?

The ancient greek astronomers divided atar according to their brightness. Till the invention of the telescope, the division was only of six classes or magnitudes. Star of the first magnitudecwere the brightest , and those of sixth were the faintest. Since the invention of the telescope , the division has gone to more then twenty. There are about 22 star of the first magnitude , that is, the brightest star. The brigtest star of all is Sirius, which has a magnitude of -1.6, making it over 1000 times brighter then the faintest star we can see with naked eye. The number of star increase as we go down in magnitude. There are about 1,000,000,000 star of the 20^th magnitude.

What is iceberg?

An iceberg is a piece of glacier that broken off at the edge, which touch the sea. These huge pieces of ice lie submerged under the surface of the water. Icebergs vary greatly in size. Smaller one measuring from 5 to 10 meter across are called growler. But the most common one are those, which measure over 100meters. There are some giant icebergs is only eight – ninths as heavy as sea water, so that one-ninth of it sticks out above sea level and the eight-ninth are below. Some of them can weigh as much as 180,000,000 tones. Due to the above two facts, they do not drift the winds. rather , they follow the ocean current . When they reach the warmer latitudes, the melt. Those that do not melt, pose danger to ships.

How the caves formed?

Caves are deep hollow place in the rock side of hills or cliffs. The larger one are called caverns. Some caves were formed by the Constance beating of the sea waves against the rock. Some caves appeared under the surface of the earth. These are usually the old course of underground streams, which have worn away the soft rock, such as limestone. Atoll other were formed by the valconic shifting of surface rock by eruption of hot lava. Some caves have opening through their roofs, called sink holes. Some caves have galleries in tiers or rows, one above the other. Then, here are those caves, which are formed in the limestone where water percolates down, carring bits of lime, which build into column called stalagmite.

How are mounten formed?

Defend on they type of formation, mountains are of four types. First , the folded mountains , which are made up of rock layers, squeezed by great pressure into large folds. Example of this kind are the Appalachian and the alps mountain. Second , there are dome mountain where the rock layers were forced up by lava coming with great pressure from below the earth surface. Example are the black hills of south Dakota. Third are the block mountain, which are formed as a result  of breaks or faults in the earth’ crust. Example of such are the sierra Nevada range of California. The last are volcanic mountain, which are made up of lave , ash and cinders poured out  from within the earth. The example include mount rainier in the united states,  and fujima in japans. At the same time, rocky mountain are formed through all the above process.

What is a spring?

Below the surface of the earth, there is a zone where are opening air all rocks are completely filled with water. A spring occurs when water finds a natural opening in the ground that is below this water table. Like an opening in the side of the valley, actually the spring water is flowing downwards. Those springs, which receive water from deep within the water zone, flow all the year round and are called permanent spring. Some spring have their opening near the water table. They actually flow only during the rainy season when the water level is at its highest. These springs are called intermittent spring. As spring water actually underground water, it carrying some mineral on it. When the spring water contains an unusual amount of mineral matter, it is called a mineral spring. Also , some spring water comes in the contended with hot , underground rocks, and it get hot. They are called thermal or hot spring.

How are waves formed?

Waves are formed by the wind. The energy in the wind formed waves, which move energy from one place to another place. In the wave, the water particles just move up and down. They don’t move from one place to another. As the wave reaches the shore , at some distance from the shore, the bottom of wave hits the ocean floor and stops, while the top parts still move on. This , then, topples over and thus forms a break. The energy in the waves can be felt of you just stand in the wave. You feel yourself being caring away.

How does wind originated?

this one about wind energy.

In general, there are two types of winds. Those that are local and those that go long distance over the earth. The winds on the seashore are simple of local winds. During that daytime, the land gets heated , the air above it rises, and cool wind take its place from the sea. At night, the land is cooler then the sea, the hotter air above the sea rises up, and the cool winds from the land take it palace. Thus, this is continue sly process. The hottest place on the earth are around the equator. The air above is rises and at certain latitudes, it gets cooled and comes down. The winds blowing towards the equator are the trade winds and those blowing toward the poles are called the westerly.