User:MubinMumtaz

WHAT A KNOWLEDGE !

Joseph Lister (1827-1912) This British Surgeon discovered that infections during surgery were caused by germs. He made use of carbolic acid to kill the germs. This had a dramatic effect and the number of deaths during surgery fell rapidly. Substances such as carbolic acid, that kill or prevent the growth of germs, are called antiseptics.

The ocean-dwelling blue whale is much bigger than an elephant. It is the largest living animal in the world: forty meters in length with a weight equal to about thirty adult elephants.

The plant with the biggest flowers is Rafflesia. Its flowers grow to have a diameter of about 1 meter. The flowers give off the smell of rotting meat to attract pollinating flies.

Snakes have special organ called Jacobson's organ of its mouth. The snake continuously flicks its tongue to pick up chemicals form the air. It then presses its tongue into the Jacobson's organ. Special cells in the tongue detect the smell.

The Sahara desert in Africa was formed because the Romans captured the lions for pleasure. This reduced the lion population, and caused an increase in the population of herbivores. The herbivores ate up all the plants and grass and the area became the largest desert in the world.

Some liquids such as water or milk flow easily. However, others such as honey or tar flow very slowly. They are said to be viscous liquids.

The Greek philosopher Aristotle who lived in 4th century BC believed that all matter was made up of just four elements arranged in different proportions. They were fire, air, water and earth.

Some substances, when mixed do not form solutions suspensions. They form colloids. Blood, boiled starch, aerosols and smoke are examples of colloids. When a bright source of light is shone through a colloid e.g. boiled starch, the colloid appears very bright, yet it passes through filter paper without leaving any residue. Colloid particles are smaller in size compared to those of suspensions.

Atomic clocks are the most accurate. Time measurements in atomic clocks are based on vibrations of atoms. These vibrations are very regular and atomic clocks are accurate to one second in 3000 years.

Tyres of ordinary cars have grooves in increase friction with the road, so that the car does not skid on the roads. However, tyres of racing cars are smooth to reduce friction so that the can go faster. Such tyres are called slicks.

Water is sometimes lifted from a river to irrigate a field, with a device called an Archimedes's screw. Each time the screw turns, it lifts the water a little bit higher up inside a tube. This device was invented by Archimedes nearly 2200 years ago to pump out water from a large ship.

Archimedes (212 BC.-287 BC.) was a great scientist and mathematician. He was born in Sicily and completes his study in Alexandria. He was the true originator of the lever as machine. His contribution in geometry and mechanics made him famous. He designed various kinds of levers and built cranes that could even lifts ships. His knowledge of lever, pulley, wheels and axles helped the Greek army in its war against the Romans and then he was killed by the Roman army.

Sound travels faster in water than in air. It also loses its energy much more slowly. Therefore, sound can travel much greater distances in water than in air. Whales and dolphins can use sound to communicate even when they are hundreds of kilometers away from each other.

Our eyes are best at receiving green light, the most common color in nature.

Charles Augustin Coulomb (1736-1806). The unit of measuring amount of charge is called "Coulomb" and is named after this French physicist. Coulomb made sensitive instruments to measure the force between electric charges. He also worked on friction and magnetism.

The deepest ocean trench is in the Mariana Trench in the pacific ocean near Guam, it is 11, 033 meters or 36,198 feet deep.

PVC which is a plastic is the short form of Poly Vinyl Chloride.

Oxygen, Sulphur dioxide and Hydrogen was discovered by priestly.

The only liquid metal is mercury.

The most reactive metal is "Na"(Sodium).

The most common solvent in nature is water.

Pythagoras is known as the father of Algebra.

Harbi-Al-Himyari who is the teacher of Jabir Ibn Hayyan, is considered the father of Chemistry.

antoin-laurent de lavoisier is considered the father of modern chemistry.

Technically Isaac Newton would be more likely to deserve the name father of physics.

Albert Einstein would be more likely to be called the father of astrophysics.

solar energy Radiation from the Sun that can produce heat, generate electricity, or cause chemical reactions. Solar collectors collect solar radiation and transfer it as heat to a carrier fluid. It can then be used for heating. Solar cells convert solar radiation directly into electricity by means of the photovoltaic effect. Solar energy is inexhaustible and nonpolluting, but converting solar radiation to electricity is not yet commercially competitive, because of the high cost of producing large-scale solar cell arrays and the inherent inefficiency in converting light to electricity. The energy transmitted from the Sun. The upper atmosphere of Earth receives about 1.5 × 1021 watt-hours (thermal) of solar radiation annually. This vast amount of energy is more than 23,000 times that used by the human population of this planet, but it is only about one two-billionth of the Sun's massive outpouring—about 3.9 × 1020 MW. See also Sun The power density of solar radiation measured just outside Earth's atmosphere and over the entire solar spectrum is called the solar constant. According to the World Meteorological Organization, the most reliable (1981) value for the solar constant is 1370 ± 6 W/m2. See also Solar constant. Solar radiation is attenuated before reaching Earth's surface by an atmosphere that removes or alters part of the incident energy by reflection, scattering, and absorption. In particular, nearly all ultraviolet radiation and certain wavelengths in the infrared region are removed. However, the solar radiation striking Earth's surface each year is still more than 10,000 times the world's energy use. Radiation scattered by striking gas molecules, water vapor, or dust particles is known as diffuse radiation. Clouds are a particularly important scattering and reflecting agent, capable of reducing direct radiation by as much as 80 to 90%. The radiation arriving at the ground directly from the Sun is called direct or beam radiation. Global radiation is all solar radiation incident on the surface, including direct and diffuse. See also Solar radiation. Solar research and technology development aim at finding the most efficient ways of capturing low-density solar energy and developing systems to convert captured energy to useful purposes. Also of significant potential as power sources are the indirect forms of solar energy: wind, biomass, hydropower, and the tropical ocean surfaces. With the exception of hydropower, these energy resources remain largely untapped. See also Energy sources. Five major technologies using solar energy are being developed. (1) The heat content of solar radiation is used to provide moderate-temperature heat for space comfort conditioning of buildings, moderate- and high-temperature heat for industrial processes, and high-temperature heat for generating electricity. (2) Photovoltaics convert solar energy directly into electricity. (3) Biomass technologies exploit the chemical energy produced through photosynthesis (a reaction energized by solar radiation) to produce energy-rich fuels and chemicals and to provide direct heat for many uses. (4) Wind energy systems generate mechanical energy, primarily for conversion to electric power. (5) Finally, a number of ocean energy applications are being pursued; the most advanced is ocean thermal energy conversion, which uses temperature differences between warm ocean surface water and cooler deep water to produce electricity. See also Biomass; Photovoltaic cell; Wind. Solar energy can be converted to useful work or heat by using a collector to absorb solar radiation, allowing much of the Sun's radiant energy to be converted to heat. This heat can be used directly in residential, industrial, and agricultural operations; converted to mechanical or electrical power; or applied in chemical reactions for production of fuels and chemicals. A solar energy system is normally designed to be able to deliver useful heat for 6 to 10 h a day, depending on the season and weather. Storage capacity in the solar thermal system is one way to increase a plant's operating capacity. There are four primary ways to store solar thermal energy: (1) sensible-heat-storage systems, which store thermal energy in materials with good heat-retention qualities; (2) latent-heat-storage systems, which store solar thermal energy in the latent heat of fusion or vaporization of certain materials undergoing a change of phase; (3) chemical energy storage, which uses reversible reactions (for example, the dissociation-association reaction of sulfuric acid and water); and (4) electrical or mechanical storage, particularly through the use of storage batteries (electrical) or compressed air (mechanical). See also Energy storage. Photovoltaic systems convert light energy directly to electrical energy. Using one of the most versatile solar technologies, photovoltaic systems can, because of their modularity, be designed for power needs ranging from milliwatts to megawatts. They can be used to provide power for applications as small as a wristwatch to as large as an entire community. They can be used in centralized systems, such as a generator in a power plant, or in dispersed applications, such as in remote areas not readily accessible to utility grid lines. Biomass energy is solar energy stored in plant and animal matter. Through photosynthesis in plants, energy from the Sun transforms simple elements from air, water, and soil into complex carbohydrates. These carbohydrates can be used directly as fuel (for example, burning wood) or processed into liquids and gases (for example, ethanol or methane). Biomass is a renewable energy resource because it can be harvested periodically and converted to fuel. See also Carbohydrate; Photosynthesis. Wind is a source of energy derived primarily from unequal heating of Earth's surface by the Sun. Energy from the wind has been used for centuries to propel ships, to grind grain, and to lift water. Wind turbines extract energy from the wind to perform mechanical work or to generate electricity. Ocean thermal energy conversion uses the temperature difference between surface water heated by the Sun and deep cold water pumped from depths of 2000 to 3000 ft (600 to 900 m). This temperature difference makes it possible to produce electricity from the heat engine concept. Since the ocean acts as an enormous solar energy storage facility with little fluctuation of temperature over time, ocean thermal energy conversion, unlike most other renewable energy technologies, can provide electricity 24 h a day.

POSTAL CODES FOR KARACHI: Airport 72500 Baldia Town 75760 Board of Secondary Education 75150 Cantt 75530 City GPO 7100 Clifton 75600 COD 75250 Darul-uloom 75180 Defence Society 75500 Export Processing Zone 75150 Federal B Area 75950 Gulshan-e-Iqbal 75300 Habib Bank 75650 Hotel Metropole 75520 Jinnah Post Graduate Medical Center 75510 Karachi GPO 74200 Karachi University 75270 Keemari 75620 Korangi Creek 75190 Korangi GPO 74900 Landhi Colony 75160 Liaqatabad 75900 Liyari 75660 Malir Cantt 75070 Malir City 75050 Manghopir 75890 Manora 75640 MariPur(CE) 75780 Maripur(FA) 75750 Mehmoodabad 75460 Model Colony 75100 Murad Memon Goth 75040 National Cement Industry (DALMIA) 75260 Nazimabad GPO 74700 New Karachi 75850 New Town GPO 74800 North Nazimabad GPO 74600 Orange Town 75800 P.C.S.I.R 75280 P.E.C.H.S 75100 Pakistan Machine Tool Factory 75760 Pakistan Naval Armament Depot 75790 Pakistan Steel Mills 75800 Pakistan Steel Mills Town Ship 75200 Port Muhammad Bin Qasim 75020 Quaidabad 75120 Rafa-e-Aam Society 75210 S.I.T.E 75700 Saddar GPO 74100 Shah Faisal Colony 75230 Shahra-e-Faisal 75350 Sher Shah Colony 75730 Sindh Governor House 75580 Nishter Road 74550

How do the color blind know if a stoplight is red or green? Traffic lights are stacked in a standardized order, with red on top, green on the bottom, and amber, when it exists, in the middle. This way, even someone who is color blind will be able to tell what color is lit by the illuminated signal's placement on the stack. Sometimes, the lights are horizontal; in this case, red is usually to the right, green to the left. Amber is still in the middle. When traffic signals were first developed, they looked more like semaphores, placed in the middle of an intersection, with an arm that raised or lowered, directing the flow of traffic. Garrett Morgan, born on this date in 1877, came up with the idea of adding a third position to the semaphore, signaling drivers that it would soon be time to stop. The addition of this signal gave drivers time to adjust to the change, thereby saving lives and damage to their vehicles.

Why is Mars red?

The planet Mars looks red because of the large quantity of iron oxide, or rust, on the orb's surface. Mars and Earth are the third and fourth planets in distance from the Sun. Their days are pretty equal in length (Mars has a solar day of 24 hours and 39 minutes), but because Mars is so much farther from the Sun, a Mars year is almost twice as long as an Earth year (687 days). Mars has two moons, which are named Phobos and Deimos for the Greek mythology characters who were battle companions to their father, Ares (known to the Romans as Mars). Dozens of spacecraft have been sent to Mars for research purposes. One of the most successful of these missions was the Viking Program. The Viking 1 landed on this date in 1976, taking the first color pictures of the red planet.

UNITED KINGDOM A country of western Europe comprising England, Scotland, Wales, and Northern Ireland. Beginning with the kingdom of England, it was created by three acts of union: with Wales (1536), Scotland (1707), and Ireland (1800). At the height of its power in the 19th century it ruled an empire that spanned the globe. London is the capital and the largest city. Population: 60,800,000.

PAKISTAN

Country, southern Asia. Area: 307,374 sq mi (796,096 sq km). Population (2005 est.): 153,960,000. Capital: Islamabad. The population is a complex mix of indigenous peoples who have been affected by successive waves of migrations of Aryans, Persians, Greeks, Pashtuns, Mughals, and Arabs. Languages: Urdu (official), Punjabi, Pashto, Sindhi, Balochi. Religions: Islam (official; predominantly Sunni); also Christianity, Hinduism. Currency: Pakistani rupee. Pakistan may be divided into four regions: the northern mountains, the Balochistan Plateau, the Indus Plain, and the desert areas. The Himalayan and Trans-Himalayan ranges form the great mountain areas of the northernmost part of the country; some of the highest peaks are K2 and Nanga Parbat. The country has a developing mixed economy based largely on agriculture, light industries, and services. Remittances from Pakistanis working abroad are a major source of foreign exchange. Pakistan is a federal republic with two legislative houses; its chief of state is the president, and its head of government is the prime minister. The area has been inhabited since the 3rd millennium BCE. From the 3rd century BCE to the 2nd century CE, it was part of the Mauryan and Kushan kingdoms. The first Muslim conquests were in the 8th century CE. The British East India Co. subdued the reigning Mughal dynasty in 1757. During the period of British colonial rule, what is now (Muslim) Pakistan was part of (Hindu) India. The new state of Pakistan came into existence in 1947 by act of the British Parliament. The Kashmir region remained a disputed territory between Pakistan and India, with tensions resulting in military clashes and full-scale war in 1965. Civil war between East and West Pakistan in 1971 resulted in independence for Bangladesh (formerly East Pakistan) in 1972. Many Afghan refugees migrated to Pakistan during the Soviet-Afghan war in the 1980s and remained there during the Taliban and post-Taliban periods. Pakistan elected Benazir Bhutto, the first woman to head a modern Islamic state, in 1988. She and her party were ousted in 1990, but she returned to power in 1993 – 97. Conditions became volatile during that period. Border flare-ups with India continued, and Pakistan conducted tests of nuclear weapons. Political conditions worsened, and the army carried out a coup in 1999.

Population:	176,242,949 (July 2009 est.) Religions:	Muslim 95% (Sunni 75%, Shia 20%), other (includes Christian and Hindu) 5% Languages:	Punjabi 48%, Sindhi 12%, Siraiki (a Punjabi variant) 10%, Pashtu 8%, Urdu (official) 8%, Balochi 3%, Hindko 2%, Brahui 1%, English (official; lingua franca of Pakistani elite and most government ministries), Burushaski and other 8% National Symbols of Pakistan[41] Flag	Flag of Pakistan Emblem	Faith, Unity, Discipline Anthem	Qaumi Tarana Animal	Markhor Bird	Chukar Flower	Jasmine Tree	Cedrus deodara Juice	Sugarcane juice Sport	Field hockey Dress	Shalwar Kameez

INDIA A country of southern Asia covering most of the Indian subcontinent. Aryans from the northwest invaded c. 1500 BC, pushing Dravidian and other peoples to the south. Most of India was unified by the emperor Asoka in the 3rd century BC. It experienced a golden age in the 4th and 5th centuries AD before being invaded c. 1000 by Muslims and later by the Mongol conqueror Baber, who established the Mogul empire (1526-1857). Various European powers established trading posts in the 16th and 17th centuries, with the British assuming authority over India in 1857. In the 20th century, India gained its independence from Great Britain (1947) following a campaign of civil disobedience led by the pacifist Mohandas Gandhi. Its concomitant partition into the separate countries of India and Pakistan resulted in a tumultuous migration of Muslims to Pakistan and Hindus and Sikhs to India in which approximately one million people died. New Delhi is the capital and Mumbai (Bombay) the largest city. Population: 1,130,000,000. Insert non-formatted text here  Insert non-formatted text here