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Saturday, February 18, 2012

CARBORUNDUM

Edward Goodrich Acheson patented a method of making an abrasive he named Carborundum - 
By Mary Bellis
On February 28, 1893, Edward Goodrich Acheson (1856–1931) patented a method for making an industrial abrasive he called "Carborundum" or silicon carbide. On May 19, 1896, Edward Goodrich Acheson was also issued a patent for an electrical furnace used to produce carborundum. The United States Patent Office named carborundum as one of the 22 patents most responsible for the industrial age (1926). According to the National Inventors Hall of Fame, "without carborundum, the mass production manufacturing of precision-ground, interchangeable metal parts would be practically impossible."
Acheson went on to discover that when carborundum was heated to a high temperature it produced an almost pure and perfected form of graphite that could be used as a lubricant. He patented his graphite-making process in 1896.
During his lifetime, Edward Goodrich Acheson was granted 70 patents for industrial abrasives, several graphite products, processes for the reduction of oxides, and refractories.
Earlier in Acheson's career, the inventor had worked for Thomas A. Edison. In 1880, Acheson helped in the development of the incandescent lamp at Edison's laboratories at Menlo Park, N.J.

Friday, February 17, 2012

Interesting facts about gold


Gold is a precious metal, high value, but you may not be able to fully understand it. Here are 10 interesting facts about gold that you might not know before.

1. Gold is probably the first metal that prehistoric humans had processed.The age of the gold jewelry which archaeologist found in Bulgaria can date back to 4000 BC. So, the Age of gold emerged just overlapped with the Stone Age.

2. The 7th century BC, gold wire was used to install false tooth by Italian dentist. Since the early 16th century, gold filling was recommended for filling the cavity.
3. In Aztec, gold is written as “teocuitlatl”, which means “Gold’s shit”.
4. Gold with high ductility and malleability. With casting, a piece of one ounce of gold can be turned into five millionths inch thick semi-transparent gold. Or can be stretched to fifty miles long and five microns in diameter, equivalent to one-tenth of the diameter of a hair.
5. The precious metal also has the characteristics of difficult to destroy.From ancient times to the present, it has been said that “Gold has its price.”  So we can recycle them. All the gold discovered in the past, eighty-five percent are still in use today.

6. Outside the lunar module of the United States “Apollo ” airship was coated with gold foil, with the aim to protect astronauts from radiation.Even now, the helmet worn by astronauts is still coated with a thin gold membrane to protect astronaut’s eyes from intense light.
7. The methods of refining gold will destroy the environment in some extent. Gold mine will dumped a lot of cyanide into the ditch, and pour the nitrogen oxides and sulfur oxides into the air.
8. In gold reserve, the United States ranks first in the world. However, if included the gold ornaments, then India will grab the top spot, twenty percent of the gold used as decoration in the world, were used in Indian saris.
9. On the surface of the Earth, the greatest concentration of gold is in ocean, it’s estimated at around one hundred million tons. Unfortunately, so far no one has found an effective method to extract gold from the ocean.
10. However, compared with the gold reserves in space, that is dwarfed.According to the data of NEAR airship sent back in 1999. The amount of gold at one planet of “Eros” is more than the sum of that has ever been mined on the earth. Regrettably, we don’t know how to mine the gold in space.

Thursday, February 16, 2012

Robert Goddard Fires His First Liquid-Fuel Rocket..1926


Robert Goddard and His Rockets


Early Rockets          

    Rockets were invented by the Chinese, a spin-off from their invention of gunpowder--some time around the year 1000, perhaps earlier. Rockets added a new dimension to fireworks--another Chinese contribution--but, invevitably, they were also applied to warfare, as missiles to set the enemy's cities on fire.
    The British took notice in 1791, when Indian troops, under Tipoo Sultan, employed rockets against them. William Congreve, a British officer, developed a military rocket and in 1806 urged its use against Napoleon. "The rocket's red glare" in the US anthem refers to the use of Congreve rockets in 1814 in an unsuccessful British attack on Fort McHenry, outside Baltimore. The aim of such rockets was notoriously inaccurate, and their use declined as artillery improved. However, commercial rockets were sold for use by ships, for carrying a line to the shore in case of shipwreck.
    Still, rockets were the only credible way of reaching distant space. One visionary who realized this was Konstantin Tsiolkovsky (1857-1935), a Russian teacher who enthusiastically promoted spaceflight and wrote books on the subject, long before the idea received serious consideration.
   

Goddard

    Another was a young American,Robert Hutchins Goddard(1882-1945). A native of Worcester, Massachusetts, Goddard's family was staying at the suburban home of friends in Worcester when, on October 19, 1899, he climbed into an old cherry tree to prune its dead branches. Instead, he began daydreaming:


      "It was one of the quiet, colorful afternoons of sheer beauty which we have in October in New England, and as I looked toward the fields at the east, I imagined how wonderful it would be to make some device which had even the possibility of ascending to Mars, and how it would look on a small scale, if sent up from the meadow at my feet."

      That was when young Goddard decided to pursue the idea of spaceflight. He later wrote
      "I was a different boy when I descended the tree from when I ascended, for existence at last seemed very purposive."

    October 19 became "Anniversary Day," noted in his diary as his personal holiday. For instance, in 1913, he made the following priority list ("order") of things-to-do:
Worcester, October 19, 1913
(Anniversary Day)
    Order: complete patent application if necessary of nozzle and plurality; take out application on reloading feature; also complete application for electric pump; repeat calculation carefully, for smaller intervals; look up Darwin's theory of the lunar motion; and look up meteors. Also try a jet.
    The patent application was for US patent #1,103,503, granted in July 1914 together with an earlier one, #1,102,653. "Plurality" was Goddard's term for multiple rocket stages, and the patents also covered expansion nozzles and liquid fuel, although Goddard did not experiment with them until 1915 and 1922, respectively.

Goddard's First Rocket Experiments

    In 1915, as assistant professor at Clark University, Worcester, he began experiments on the efficiency of rockets. He bought some commercial rockets and measured their thrust using a ballistic pendulum, a heavy mass suspended by ropes, to which the rocket was attached. The rocket was fired, and the height to which the pendulum rose provided a measure of the total momentum (mass times velocity) imparted to it. Goddard also used an equivalent set-up, where the mass pushed against a spring, instead of being suspended.
    (Concerning the origins of the ballistic pendulum, see the historical note at the end of this web page.)
    It can be shown from Newton's laws that the total momentum of a system free from outside forces is conserved; that is actually another formulation of the conservation of the center of gravity, mentioned in the discussion of rocket propulsion. Therefore the momentum given to the pendulum in one direction had to be equal to the momentum mv imparted to the rocket's gas jet and that momentum determined the length and height of its swing. By weighing the rocket before and after firing, Goddard could derive the mass mof the ejected gases and from that deduce v. For a 1-pound Coston ship rocket, he found that v was about 1000 ft/sec (300 m/sec).

De Laval's Nozzle

    A rocket is essentially a heat engine, a device for converting the energy of heat (obtained from the chemical energy of the fuel) into mechanical energy--here the kinetic energy mv2/2 of its exhaust jet. Knowing m and v, Goddard could derive the kinetic energy given to the gas, and by burning a measured amount of the fuel, absorbing the heat (e. g. in water) and measuring the rise in temperature, the total amount of chemical energy converted to heat could also be obtained. The conclusion was rather disappointing: only about 2% of the available energy contributed to the speed of the jet.
    Could this be improved? Luckily for Goddard, this problem had been solved by Gustav De Laval, a Swedish engineer of French descent. In trying to develop a more efficient steam engine, De Laval designed a turbine whose wheel was turned by jets of steam.
 De Laval's turbine:
  4 nozzles, one in
 cross section.
   The critical component, the one in which heat energy of the hot high-pressure steam from the boiler was converted into kinetic energy, was the nozzle from which the jet blew onto the wheel. De Laval found that the most efficient conversion occured when the nozzle first narrowed, increasing the speed of the jet to the speed of sound, and then expanded again. Above the speed of sound (but not below it! ) this expansion caused a further increase in the speed of the jet and led to a very efficient conversion of heat energy to motion. Nowadays steam turbines are the preferred power source of electric power stations and large ships, although they usually have a different design--to make best use of the fast steam jet, De Laval's turbine had to run at an impractically high speed. But for rockets the De Laval nozzle was just what was needed.
    Goddard experimented on his ballistic pendulum with various nozzle designs, using a small metal combustion chamber filled with a type of gunpowder, ignited by electricity. The end of the chamber was threaded, so that nozzles of various designs could be screwed onto it and tested. Using a De Laval nozzle, he obtained jet velocities between 7000 and 8000 ft/sec and efficiencies of up to 63%. Later he replaced the ballistic pendulum with a more compact device, in which the thrust of the rockets did not lift a pendulum against gravity but compressed a calibrated spring. With that device he showed that (contrary to some popular claims) rockets worked just as well in a vacuum.
    As Goddard himself noted, that made the rocket the most efficient of all heat engines, better than piston-driven steam engines (21%) and Diesel engines (40%). No wonder: from the second law of thermodynamics, the theoretically attainable efficiency of a heat engine increases with its operating temperature, and no other heat engine runs as hot as a rocket.
 A rocket engine at the
  Smithsonian, cut open to
 show convergent-diver-
 gent DeLaval nozzle.
    De Laval's nozzle turned spaceflight from a vague dream into a real possibility. Goddard communicated his results to the Smithsonian Institution in Washington and asked for support to develop a rocket capable of probing the high atmosphere. His original plan (the "reloading feature" in his priority list) was to feed the combustion chamber with solid chunks of fuel, somewhat in the manner in which bullets were fed to a machine gun. In January 1917 the Smithsonian responded with a grant of $5000, and Goddard began his rocketry career.    After the US entered World War I, Goddard also worked for a while on military rockets, but none of his designs were implemented, though rockets somewhat similar to his design were turned in World War II into an effective weapon against tanks, known as the bazooka (a variant of this is now known as "rocket propelled grenade" or RPG).
Note: The autobiographical book by Homer Hickam "October Sky" (anagram of its original title "Rocket Boys"; later made into a film) tells of a group of high-school students in a poor Appalachian coal-mining town who, taken by the idea of space flight, design and fly home-built rockets of greater and still greater range. Their break-through comes when they discover in a book the design of the De-Laval Nozzle.

Liquid Fuel

    The idea of feeding the rocket with a continuous stream of solid charges also proved unfeasible, and in 1922 Goddard went back to his alternative idea, proposed independently by Hermann Oberth in Germany and also noted by Tsiolkovsky: a liquid-fuel rocket. It would have two lines running into its combustion chamber, one feeding fuel, the other oxygen, similar to the way a steel-cutting blowtorch operated, except here both lines carried liquids, not gases--in Goddard's design, gasoline and liquid oxygen.
    Such a rocket promised very high efficiency, but also posed serious technological challenges. Both fluids had to be pumped at a steady rate, and one of them, liquid oxygen, was extremely cold. The high temperature of combustion in pure oxygen required heat-resistant materials, and to help overcome this, Goddard developed the technique of having the liquid oxygen cool the combustion chamber on its way from the fuel tank. This method is still use: in the picture on the right, the outer part of the nozzle is covered with a large number of metal pipes, through which the cold fuel flows on its way to the combustion chamber. Another completely novel problem which faced Goddard was the guidance and control of the rocket in flight.
    Robert H. Goddard besides
    1926 liquid- fueled rocket.
    The rocket is on top, recei-
    ving its fuel by two lines
    from the tank at the bottom.
    On March 16, 1926, Goddard flight-tested his first liquid-fuel rocket. He thought stable flight could be obtained by mounting the rocket ahead of the fuel tank, with the tank shielded from the flame by a metal cone and the lines for fuel and oxygen pulling it behind the rocket: the design worked, but did not produce the hoped-for stability. The rocket burned about 20 seconds before reaching sufficient thrust (or sufficiently lightening the fuel tank) for taking off. During that time it melted part of the nozzle, while the camera with which Mrs. Esther Goddard was trying to record the flight ran out of film, so that no photographic record of that flight remains. Then it took off to a height of 41 feet, leveled off and later hit the ground, all within 2. 5 seconds, averaging about 60 mph.
    Goddard's concept seemed validated, but he was still far from a practical design. Unfortunately, he worked in isolation, without the engineering resources of a major institution. In the years that followed he continued developing his rockets--controlling their motion by gyroscopes, steering them with small vanes thrust into their exhaust jet, and building larger and faster rockets. These were tested in test stands on the ground and sometimes also in free flight, mostly at a rocket lab he established in Roswell, New Mexico.
But the actual realization of his dream fell to others who enjoyed military or national support. Goddard, unfortunately, never lived to see the age of spaceflight. He died of cancer on August 10, 1945, in Baltimore.

Wednesday, February 15, 2012

Brief history of India for ready reference/


Kingdoms

The end of the Vedic Age (1500 BC-600 BC) was followed by the rise of small kingdoms and republics in the northern parts of India and especially in the Gangetic plains of Bihar.

Maurya Dynasty

The Mauryan Empire was the first major empire in the history of India and ruled the land from 322 BC to 185 BC. Important rulers of this dynasty were Chandragupta Maurya, Bindusara, and King Ashoka. Bindusara was succeeded by his son Ashoka, the most famous of the Mauryan Kings who reign from- 273 - 232 B.C. He extended the boundaries of his empire considerably - stretching from Kashmir and Peshawar in the North and Northwest to Mysore in the South and Orissa in the East - but his fame rests not so much on military conquests as on his celebrated renunciation of war. After witnessing the carnage at the battle field of Kalinga (269 B.C.) in Orissa, Ashoka resolved to dedicate himself to Dhamma - or righteousness. The war of Kalinga was the turning point in the life of Ashoka to the extent that he shunned all forms of violence and became a strict vegetarian.

As Ashoka became a devout Buddhist, he began to spread the teachings of Buddha by issuing edicts. These edicts were sent to different parts of the empire, where they were engraved on rocks or pillars, for the common people to see and read them. These edicts were written in different scripts. Most of them were in Brahmi, which was common in most parts of the empire. The language was generally Prakrit (ancient language), as it was spoken by the common people, whereas Sanskrit was spoken by educated upper caste people.

The great Mauryan Empire did not last long after the death of Ashoka and ended in 185 BC. Weak kings on one hand and the unmanageability of a vast empire on the other caused the rapid decline of the Mauryas.

Shunga Dynasty

Ashoka died around 232 B.C. and the empire began to disintegrate under weak successors. Pushyamitra Shunga, a Brahmin general usurped the throne after slaying the last Maurya king and presided over a loosely federal polity. In subsequent centuries India suffered a series of invasions, and in the absence of a strong central authority, often fell under the spell of foreign rulers - Indo Bactrians, the Sakas and others.

The Golden Age

Satavahana Empire
The fall of the Mauryan empire and the confusion caused due to it gave birth to a new dynasty called Satavahanas, also called as Andhra dynasty. Satavahanas is one of the most celebrated dynasties of ancient India. Satavahanas ruled over large area of modern western and southern India. King Simuka, belonging to the Satavahana family in present day Andhra Pradesh founded the Satavahana dynasty after defeating the Mauryan rule in the Deccan. Satavahana kings ruled much of Deccan plateau from 50 B.C to 250 A.D. But it was his son or nephew Satakarni I who made Satavahanas as most formidable power of western and southern India. 

There were twenty-nine rulers of this dynasty according to Matsya Purana. The kings of this dynasty were great patrons of art and architecture. Buddhism flourished throughout the period and the rulers were also devoted to Vedic ritualism. They constructed several Buddhist Stupas, Viharas and Chaityas. 

The decline and fall of the Satavahana Empire left the Andhra country in a political chaos. Local rulers as well as invaders tried to carve out small kingdoms for themselves and to establish many dynasties. During the period from AD 180 to AD 624 Ikshvakus, Vishnukundins, Vakatakas, Pallavas, Anandagotras, Kalingas and others ruled over the Andhra area with their small kingdoms.

Kushan Empire (ca. 2nd century b.c.-3rd century a.d.)

The post-Mauryan period from 185 BC to AD 300 saw the emergence of a number of kingdoms all over the Indian subcontinent. Some of these states were small, while others like that of the Kushans were large. This period witnessed a spurt in migrations into India, rise in foreign trade, and development of art. In short, the time scale between 1st century BC and 3rd century AD was a period of flux. 

The Kushans originated from the Turkistan region of China. They moved towards Afghanistan in the 1st century AD and after displacing the Indo-Greeks, the Parthians and the Sakas, they established themselves in Taxila and Peshawar. The name Kushan derives from the Chinese term Guishang, used in historical writings to describe one branch of the Yuezhi-a loose confederation of Indo-European people who had been living in northwestern China until they were driven west by another group.

A number of foreigners came to India in successive waves of migrations between 200 BC and AD 100. These people settled down in different parts of India. They brought with them their own distinct cultural flavor, which, after mixing with the local cultures, enriched the cultural ethos of India. The foreigners who came into India were the Bactrian Greeks (also called the 'Indo-Greeks'), the Parthians, the Sakas, and the Kushans. With the exception of the Greeks, all others came from Central Asia. Under the rule of the Kushans, northwest India and adjoining regions participated both in seagoing trade and in commerce along the Silk Road to China.

The rule of Kanishka, the third Kushan emperor who flourished from the late first to the early/mid-second century A.D., was administered from two capitals: Purushapura (now Peshawar) near the Khyber Pass, and Mathura in northern India. Under Kanishka's rule, at the height of the dynasty, Kushan controlled a large territory ranging from the Aral Sea through areas that include present-day Uzbekistan, Afghanistan, and Pakistan into northern India as far east as Benares and as far south as Sanchi.

Gupta Dynasty

Gupta dynasty was ruled from around 320 to 600 CE and covered most of Northern India. It was one of the largest political and military empires in the world. The time of the Gupta Dynasty is referred to as Golden Age of India. It signaled the emergance of a leader, a Magadha ruler, Chandragupta I. Chandragupta successfully combated the foreign invasion and laid foundation of the great Gupta dynasty, the emperors of which ruled for the next 300 years, bringing the most prosperous era in Indian history. Srigupta I (270-290 AD) who was perhaps a petty ruler of Magadha (modern Bihar) established Gupta dynasty with Patliputra or Patna as its capital.

Samudragupta was perhaps the greatest king of Gupta dynasty. He ruled from around 335 to 380 AD. But the most detailed and authentic record of his reign is preserved in the rock pillar of the Allahabad, composed by Harisena.

Samudragupta's son, Chandragupta II tried to be better than his father, and most historians agree he was certainly successful. Vikramaditya is THE LEGENDARY emperor of India. During his reign India was at the prosperity and luxuriousness, so he also took a title of 'Vikramaditya'. Vikramaditya's reign was perhaps the most prosperous and progressive reign in the entire Indian history.
Vikramaditya was succeeded by his able son Kumargupta I. He maintained his hold over the vast empire of his forebears, which covered most of India except southern four states of India. He ruled from 415-455 AD. He performed the Ashwamegha Yagna and proclaimed himself to be Chakrawarti, king of all kings. During his reign the Gupta Empire was at its zenith.

After Kumargupta I, Skandagupta has succeeded the Gupta Dynasty. When Skandagupta took over the Gupta Empire, he had faced formidable enemies, the Huns. He successfully repelled their early invasions and proved to be able king and administrator in time of crisis. In spite of heroic efforts of SkandaGupta, Gupta empire did not survive long the shock it received from invasion of the Huns and internal uprising of Pushyamitras.

The Classical Age

Harsha's Empire
Harsha or Harshavardhana was an Indian emperor who ruled Northern India for over forty years. He was the son of Prabhakar Vardhan and younger brother of Rajyavardhan, a king of Thanesar. He ruled from 590-647 AD. Harshavardhana made efforts at empire building in the second half of the seventh century. He belonged to the Pushabhukti family, who ruled in Thaneshwar, north of Delhi. Harsha was perhaps one of the greatest conquerors of Indian history, and unlike all of his conquering predecessors, he was a brilliant administrator. He was also a great patron of culture.

His reign is comparatively well documented by his court poet, Bana, who composed an account of his rise to power, Harshacharita. The Chinese Buddhist pilgrim, Hieun Tsang, who visited India during his reign, also left a lengthy account of his travels. Hieun Tsang noticed that at the time of Harsha, Buddhism was not as popular in all parts of India as he had thought it would be. But in eastern India, it was still popular. Nalanda University was still a famous center of Buddhism. He also recorded the existence of a rigid caste system.

The most significant achievements of this period, however, were in religion, education, mathematics, art, and Sanskrit literature and drama. Soon after Harsha's death, apparently without any heirs, his empire died with him. After Harsha Vardhana North and north west part of India was mostly controlled by Pratihara Kings while Central India and part of South was mostly under Rashtrakutas dynasty (753-973 AD ) Pala Kings (750-1161 AD) ruled the Eastern part of India (present Bengal and Bihar).

The Chalukyas, Pallavas, and Pandyas

After Satvahan, the next great empire in the Deccan was the Chalukya Empire. Pulakesin I, first ruler of the Chalukya dynasty. Pulakesin II was the greatest ruler of the Chalukya dynasty. The Chalukyas built their kingdom on the ruins of the Vakatakas, who in turn had built theirs on the remains of the Satavahanas. They established their capital at Vatapi (modern Badami). The Chalukyas were sworn enemies of the Pallavas and rose to power in Karnataka. The first great ruler of the Chalukya dynasty was Pulakesin I. The kingdom was further extended by his sons Kirtivarman and Mangalesa by waging many successful wars against the neighbours including Mauryans of the Konkans. They were overthrown by a chief named Dantidurga who laid the foundation of the next great empire of Karnataka and Maharashtra, that of Rashtrakutas.

Pallavas established a capital at Kanchipuram (Tamil Nadu state) and came to hold sway in the south. Sivaskandhavarman who ruled in the first part of the fourth century CE was an independent ruler. He established his capital at Kanchi which continued as Pallava capital for centuries. Huen Tsang the Chinese monk-scholar, who visited Kanchi in 642 CE, writes that the Pallava country was more than thousand miles in area and calls it Dravidanadu. They were defeated by the Guptas in about 360 AD but continued to rule until the Cholas finally conquered their lands. Later, in the 9th century, the Pallava themselves were definitely conquered by the Chola from Tanjore and became their vassals. 

Pandyas were the longest ruling dynasty of Indian history. They ruled the southern most part of India and the capital of the Pandya kings was Madurai (Tamil Nadu). First Indian Ambassador from Pandya Dynasty is sent to Rome in 26 BC. After defeating the kalabhras the Pandya rulers ruled between 550 AD to 950 AD. They were called as first Pandyas. After the fall of the great pallavas and the cholas once again the Pandyas ruled the Tamil country from 1190 AD to 1310 AD. The first Pandyan Empire continued till the beginning of the Tenth Century A.D. The Cholas defeated the Pandyan ruler, Rajasimha II. Later, Veerapandya (A.D. 946-966), the last ruler of the first Pandyan Empire had been defeated and killed by Adhithya Chola. It was the end of the first Pandyan Empire.

Chola Empire

The Cholas are the earliest and the most ancient among the South Indian royal houses. The artifacts of the period found in South India mention Mahabharata as well as Ashokan edicts. They conquered Ceylon (Sri Lanka), Srivijaya, Malaya, and the Maldives islands. They had powerful navy and their marine trade and commerce extended to far east. Their art and architecture have their impact in Sumatra and Java islands of Indonesia, and in many parts of Malaysia.

The two greatest Chola kings were Rajaraja I (reigned 985-1014) who invaded Northern Cyprus and his son Rajendra Cholavarma who reigned from 1014-1044. During their reigns, Chola military expeditions were sent to the Ganges valley and the Malay archipelago, and magnificent temples were built at Tanjore. The revenue of the Cholas came from 'tax on land' and 'tax on trade'. Trade was carried on with west Asia, China and Southeast Asia. The high volume of trade led to the rapid development of towns from the 11th century onwards.

During this period, several regional languages branched off from Sanskrit. Marathi evolved from the local Prakrit, while Tamil, Telugu and Kannada stemmed from a Dravidian root, but owed much to Sanskrit. More important than the kings and their conquests is the cultural and artistic record of those times. The temple was the cultural and social center, where people used to gather.

Pratiharas - Palas - Rashtrakutas

The Pratiharas are believed to be the clan of Rajputs. The greatest ruler of the Pratihara dynasty was Mihir Bhoja. He recovered Kanauj (Kanyakubja) by 836, and it remained the capital of the Pratiharas for almost a century. The Pratihara dynasty started well under the ruler Nagabhatta-I. Though initially he had hiccups with the Rashtrakutas, he was able to leave behind a strong State comprising Malwa, parts of Rajputana and Gujarat. His successor Nagabhatta-II (805 - 839 AD) showed his military capabilities by checking out Muslim advancement and the victory over Andhra, Vidharbha, Vatsa, Sindhu and Kalinga. Towards the end of 10th century, the prestige of the Pratiharas came to and end with the humiliating submission of Rajyapala to Mahmood in 1018 AD. The successors of Pratiharas like Trilochanapala, Yasapala continued reigning for another century.

The Pala empire was founded in 730 AD. They ruled over parts of Bengal and Bihar. Dharmapala (780-812 AD) was one of the greatest kings of the Pala dynasty. He did much to restore the greatness of Pataliputra. The Nalanda University was revived under their rule. The Palas had close trade contacts and cultural links with South-East Asia.

Dantidurga laid the foundation of Rashtrakuta Empire. The Rashtrakuta's empire was the most powerful of the time. They ruled from Lattaluru (Latur), and later shifted the capital to Manyaketa (Malkhed).

The Rajputs


The Rajput who held the stage of feudal rulers before the coming of the Muslims, were a brave and chivalrous race. The name rajputs was originally taken from Raj-Putra i.e. prince or literally "king's son". In actual fact although they were Kshatriyas in the Hindu caste hierarchy, they seem to have genetically descended from the Shakas and Hunas who had invaded north India during the Gupta period and had subsequently settled down in North India and due to their war-like attitudes and been absorbed as Kshatriyas into Hindu society. Prithviraj Chouhan, Maharana Pratap was great rajput kings. According to a mythical narration, the Rajputs originated from the sacrificial fire performed by Vashistha and other saints near the Nakhi Lake on Mount Abu with a view to containing the growing strength of demons.

Vijayanagar Empire


After the departure of Muhammad bin Tughlak from the Deccan, Harihara declared independence. He and his brother Bukka I under the guidance of famous Hindu saint and the head of Sringeri Math, Vidyaranyasvami, who is also identified with the distinguished jurist Madhav Mantri, established the mighty Hindu Kingdom of Vijaynagar (the City of Victory) in 1336 AD. Vijaynagar illuminated the landscape of Deccan History for 229 years (1336-1565 AD). By 1347 AD, Malerajya and Palasige of the Goa Kadambas were incorporated into the Vijaynagar Empire. Goa formed a strategically and commercially important province on the western border of the Vijaynagar Empire.

The Islamic Sultanates

The Mughal emperors were from Afghanistan, northwest of India. Their family came from somewhere else, and they spoke Turkish and Persian, not Indian languages. Even so, they stayed in India and built their power there.

Delhi Sultanate

During the last quarter of the twelfth century, Muhammad of Ghor invaded the Indo-Gangetic plain, conquering in succession Ghazni, Multan, Sindh, Lahore, and Delhi. Qutb-ud-din Aybak, one of his generals proclaimed himself Sultan of Delhi. In the 13th century, Shams ud din Iltumish (1211 - 1236), a former slave-warrior, established a Turkic kingdom in Delhi, which enabled future sultans to push in every direction; within the next 100 years, the Delhi Sultanate extended its way east to Bengal and south to the Deccan, while the sultanate itself experienced repeated threats from the northwest and internal revolts from displeased, independent-minded nobles. The sultanate was in constant flux as five dynasties rose and fell: the Slave dynasty (1206-90), Khalji dynasty (1290-1320), Tughlaq dynasty (1320-1413), Sayyid dynasty (1414-51), and Lodi dynasty (1451-1526).

The Mughal Empire


 The first Battle of Panipat gave a deathblow to the Lodhi Empire and marked the end of the Delhi Sultanate's rule in India. It led to the establishment of the Mughal Empire in India. Babar defeated Lodi at Panipat, not far from Delhi, and so came to establish the Mughal Empire in India. Babar ruled until 1530, and was succeeded by his son Humayun, who gave the empire its first distinctive features. But it is Humayun's son, Akbar the Great, who is conventionally described as the glory of the empire. Akbar reigned from 1556 to 1605, and extended his empire as far to the west as Afghanistan, and as far south as the Godavari river. Akbar was succeeded by his son Salim, who took the title of Jahangir. In his reign (1605-1627), Jahangir consolidated the gains made by his father. The Mughal Empire survived until 1857, but its rulers were, after 1803, pensioners of the East India Company. The last emperor, the senile Bahadur Shah Zafar, was put on trial for allegedly leading the rebels of the 1857 mutiny and for fomenting sedition.

The Maratha Confederacy

The Maratha Kingdom was founded by Shivaji in 1674. The tiny Maratha kingdom, established by Chattrapati Shivaji was expanded by the Peshwas, who were the Brahmin Prime Ministers. The real credit for expanding the Maratha kingdom goes to Bajirao Peshwa I (1721-1740). The Peshwas subsequently ruled the Maratha Kingdom as defacto rulers. The Maratha Kingdom come end with the defeat of Maratha's by an Afghan army at the Third Battle of Panipat in 1761.

The Kingdom of Mysore

Mysore is correlated to the ruling of the Wodeyar dynasty, Hyder Ali and Tipu Sultan though several prominent South Indian dynasties have ruled this place. The traditional founding of the Wodeyar dynasty took place in 1399 with Yaduraya. Since then, 24 rulers have succeeded in the dynasty, the last being Jayachamaraja Wodeyar. Till the year 1610, when Srirangapatna was acquired, Mysore was the center of Wodeyar administration. It became the capital of the Kingdom of Mysore after the death of Tippu Sultan at the end of the Anglo-Mysore Wars in 1799.

The Punjab - Sikh Empire

The Sikhs established their empire in the Punjab after the death of the Mughal Emperor Aurangzeb Alamgir in 1707. Charat Singh, who was the head of one of Sikh Clans, established his stronghold in Gujranwala in 1763. Maharaja Ranjit Singh was the most powerful of all the Sikh Rulers and ruled over for complete 40 years. Ranjit Singh was also known as "The Lion of the Punjab," he died of paralysis on the 27th of June 1839. After his death the Sikh Empire was divided into small principalities looked after by several Sikh Jagirdars.

Company Rule & The British Raj

The company first established a toehold in India in 1612, when the Mughal emperor Jahangir granted them the right to establish a trading post (called a factory by the company) in Surat. Later in the century, the British East India Company opened permanent trading stations at Madras, Bombay, and Calcutta, each under the protection of native rulers. A settlement at Calcutta was established in 1690, again with the permission of the Mughal Empire. The company vied with the Portuguese and rival Dutch, French, and Danish companies. The French set up base along with the British in the 17th century. They occupied large parts of southern India. The British Empire in India - A multiplicity of motives underlay the British penetration into India: commerce, security, and a purported moral uplift of the people. The "expansive force" of private and company trade eventually led to the conquest or annexation of territories in which spices, cotton, and opium were produced.

The Independence Movement

The feeling of nationalism had started growing in the minds of Indians as early as the middle of the nineteenth century but it grew more with the formation of the Indian national Congress in 1885. Though the Congress started on a moderate platform but with the passage of time and apathetic attitude of the British government, the national movement began to shape well. The first of a series of national movements was the Non-cooperation movement (1920-1922AD). It was followed by the civil disobedience movement, after a lull. The struggle for independence continued in the 1930s but the real momentum came with the Second World War. The Congress, under the leadership of Gandhi began to prepare for the "Quit India Movement" in 1942. With the pace of developments all over the world (after the Second World War), the British came to realize that it was not possible to rule India any more and they decided to quit.

In the March of 1947 Lord Mountbatten came to India and recommended a partition of Punjab and Bengal in the face of civil war. Gandhi was very opposed to the idea of partition and urged Mountbatten to offer Jinnah leadership of a united India instead of the creation of a separate Muslim state. But this arrangement was not acceptable to many nationalist leaders, including Nehru. In July Britain's Parliament passed the Indian Independence Act. According to it August 14 and 15 were set for partition of India. Thus came into existence two independent entities- Indian and Pakistan.
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First Ever.


Sir Roger Bannister

Sir Roger Bannister in 2009
Personal information
Born23 March 1929 (age 82)
Harrow, England
Height6'2" (187 cm)
Weight154 lbs (70 kg)
Sport
SportRunning
Event(s)800m,1500m,1 mile.

Sir Roger Gilbert Bannister, CBE (born 23 March 1929) is an English former athlete best known for running the first mile in less than 4 minutes. Bannister became a distinguished neurologist and Master of Pembroke College, Oxford, before retiring in 2001.






















Sergey Bubka

Sergey Bubka in 2007
Personal information
Birth nameСергій Назарович Бубка
NationalityUkrainian
Born4 December 1963 (age 48)
VoroshilovgradUSSR (nowLuhanskUkraine)
Websitehttp://www.sergeybubka.com/
Sport
SportPole vault



Serhiy Nazarovych Bubka (UkrainianСергі́й Наза́рович Бу́бкаRussianСерге́й Наза́рович Бу́бка, Sergey Nazarovich Bubka; born 4 December 1963) is a retired Ukrainian pole vaulter. Repeatedly voted the world's best athlete,[1][2] he represented the Soviet Union until its collapse in 1991.
Bubka won 6 consecutive IAAF World Championships, an Olympics gold and broke the world record for men's pole vaulting 35 times[3] (17 outdoor and 18 indoor records). He was the first to clear 6.0 metres and the only (as of March 2011) to clear 6.10 metres (20 ft).[4][5]
































Nadia Comăneci
Personal information
Full nameNadia Elena Comăneci
Country represented Romania
BornNovember 12, 1961(age 50)
Onești
DisciplineWomen's artistic gymnastics
GymNational Training Center
Former coach(es)Béla KárolyiMarta Károlyi
ChoreographerGeza Pozar
Eponymous skillsComăneci salto (uneven bars)
Retired1981


Nadia Elena Comăneci (Romanian pronunciation: [ˈnadi.a koməˈnet͡ʃʲ]; born November 12, 1961) is a Romanian gymnast, winner of three Olympic gold medals at the 1976 Summer Olympics in MontrealQuebecCanada, and the first female gymnast ever to be awarded a perfect score of 10 in an Olympic gymnastic event. She is also the winner of two gold medals at the 1980 Summer Olympics. She is one of the best-known gymnasts in the world.[1][2][3] In 2000 Comăneci was named as one of the athletes of the century by the Laureus World Sports 








































Javier Sotomayor

Sotomayor in 2009
Personal information
Nationality Cuban
Born13 October 1967 (age 44)
LimonarMatanzasCuba
Height1.95 m (6 ft 5 in)
Weight82 kg (180 lb)
Sport
SportTrack and field
Event(s)High jump

Javier Sotomayor Sanabria (born 1967) is a Cuban former track and field athlete who specialized in the high jump and is the current world record holder.[1] The 1992 Olympic champion, he was the dominant high jumper of the 1990s; he is the only person ever to have cleared 8 feet (2.44 meters). He is widely regarded as the best high jumper of all time. Cuban boycotts of the Olympics in 1984 and 1988 and an injury in 1996 cost him chances at additional Olympic medals, but he returned to win the silver medal at the 2000 Olympics in Sydney. Sotomayor retired in 2001, pre-empting a lifetime ban for his second positive doping test (first for cocaine, then for anabolic steroids).




























Edward Jenner..did the first vaccination 
Louis Pasteur

Louis Pasteur photographed by Pierre Lamy Petit
BornDecember 27, 1822
Dole, JuraFranche-Comté, France
DiedSeptember 28, 1895 (aged 72)
Marnes-la-CoquetteHauts-de-Seine, France
NationalityFrench
FieldsChemistry
Microbiology
InstitutionsDijon Lycée
University of Strasbourg
Université Lille Nord de France
École Normale Supérieure
Alma materÉcole Normale Supérieure
Notable studentsCharles Friedel[1]
Signature