Knowledge To Kids

What Is A Snowflake?

2009-09-10T06:30:00.001-07:00

Snow is frozen water vapour. During the process of crystallization, these crystals are carried up and down in the atmosphere by air currents, during which they collect specks of dust or tiny drops of water on it. Gradually, these crystals become larger, so that soon there might be hundreds of crystals gathered around one nucleus.

When such a group becomes large enough, it begins to float down towards the ground and we call it a snowflake. The size of a snowflake depends on the temperature. The colder the temperature, the smaller the size of snowflakes formed. Some snowflakes are more than three centimeters in diameter.

Below Snowflake info from Wikipedia (Read More):-

Snowflakes begin as snow crystals which develop when tiny supercooled cloud droplets (about 10 μm in diameter) freeze. Snowflakes come in a variety of sizes and shapes. Colder environments lead to column-like development of the flakes, while warmer temperatures lead to thin and flat crystal development. Complex shapes emerge as the flake moves through differing temperature and humidity regimes. Types which fall in the form of a ball due to melting and refreezing, rather than a flake, are known as graupel, with ice pellets and snow grains as examples of graupel. Snowflakes are used as a symbol for winter tires, and for the 2002 Winter Olympics.

http://en.wikipedia.org/wiki/Snowflake

A nameless razor fusses.

How Does Iron Rust?

2009-09-10T06:13:00.001-07:00

When water falls on iron, it reacts with the oxygen in the water and forms iron oxide. This is rust. The drop of water turns reddish in colour and the rust is suspended in the water. When the water drop evaporates, the rust remains there and forms a reddish coat on the iron itself.

Once started, rust spreads even in dry air. This is due to the fact helps whatever moisture is available in the air to condense in it. It also attracts the air and holds it. Here, the phrase, Prevention is better than cure is apt because it is easier to prevent rust from starting than to prevent it from spreading once it has started. Iron articles can be prevented from rusting by coating them with a special paint.

Below Iron Rust info from Wikipedia (Read More):-

Rust is a general term for a series of iron oxides, usually red oxides, formed by the reaction of iron and oxygen in the presence of water or air moisture. Several forms of rust are distinguishable visually and by spectroscopy, and form under different circumstances.[1] Rust consists of hydrated iron(III) oxides Fe2O3·nH2O and iron(III) oxide-hydroxide (FeO(OH), Fe(OH)3). Rusting is the common term for corrosion of iron and its alloys, such as steel. Other metals undergo equivalent corrosion, but the resulting oxides are not commonly called rust. Given sufficient time, oxygen, and water, any iron mass eventually converts entirely to rust and disintegrates. The corrosion of aluminium is extremely slow because the resulting aluminium oxide forms a conformal coating, which protects the remaining aluminium. This process is known as passivation.

http://en.wikipedia.org/wiki/Rust

How Does Wind Originate?

2009-09-09T09:01:00.001-07:00

In general, there are two types of winds. Those that are local and those that go long distances over the earth. The winds on the seashores are examples of local winds. During the daytime, the land gets heated, the air above it rises, and cool winds take its place from the sea. At night, the land is cooler than the sea, the hotter air above the sea rises up, and cool winds from the land take its place. Thus, this is a continuous process.

The hottest places on the earth are around the equator. The air above it rises and the place is filled by cold winds coming from the polar regions. The warm air moves to the polar regions and at certain latitudes it gets cooled and comes down.

The winds blowing towards the equator are the trade winds and those blowing towards the poles are called the westerlies.

Below Wind info from Wikipedia (Read More):-

Wind is the flow of air or other gases that compose an atmosphere (including that of the planet Earth). On Earth and within other planetary atmospheres, wind consists of air molecules in motion. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space. Differences in density between two air masses lead to wind. Winds are commonly classified by their spatial scale, their speed, the types of forces that cause them, the geographic regions in which they occur, and their effect. While wind is often a standalone weather phenomenon, it can also occur as part of a storm system, most notably in a cyclone. While winds on Earth can be strong, the strongest winds within a planet in our solar system lie on Neptune and Saturn.

http://en.wikipedia.org/wiki/Wind

What Is An Earthquake?

2009-09-07T07:53:00.001-07:00

In areas of the Earth’s crust there are places where there is a weakness. In these regions, the crust has not settled down firmly, and there is a break in the rocks, known as a fault. Here rock masses rub against each other with great force and friction.

The energy from this rubbing is changed into vibration in the rock and to the surface. This vibration is an earthquake. The earthquake is the strongest right along the line of fault. This part is called the epicenter of the earthquake. If this is near a habitation, it brings about a great loss of life and property. The whole region gets devastated. Japan is the most earthquake-prone region of the world. Next comes the Mediterranean region.

Below Earthquake info from Wikipedia (Read More):-

An earthquake (also known as a tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. Earthquakes are recorded with a seismometer, also known as a seismograph. The moment magnitude of an earthquake is conventionally reported, or the related and mostly obsolete Richter magnitude, with magnitude 3 or lower earthquakes being mostly imperceptible and magnitude 7 causing serious damage over large areas. Intensity of shaking is measured on the modified Mercalli scale.

http://en.wikipedia.org/wiki/Earthquake

What Are Volcanoes?

2009-09-07T07:14:00.001-07:00

The centre of the earth is hot and molten. The temperature rises as we go deeper form the surface. When rocks melt, they expand, creating new mountains. Under them, there would be a space of low pressure. Molten lava fills up this place, building pressure. When the pressure exceeds the strength of the overlying crust of the Earth, it breaks out as a volcanic eruption.

The eruption lasts until the gas is gone and pressures decreases. What comes out is mainly gaseous, but large quantities of molten rock, called lava and solid particles that look like cinders and ash are also thrown out.

Central America, bordering the Pacific Ocean is an area of one of the most active volcanic activity in the world. Nearly two-third of the active ones and a large number of the dormant volcanoes are found in this area.

Volcanoes can cause great loss of life and property if it happens in a place of human dwelling.

Below Volcanoes info from Wikipedia (Read More):-

A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, ash and gases to escape from below the surface. The word volcano is derived from the name of Vulcano island off Sicily which in turn, was named after Vulcan, the Roman god of fire.[1]

Volcanoes are generally found where tectonic plates are diverging or converging. A mid-oceanic ridge, for example the Mid-Atlantic Ridge, has examples of volcanoes caused by divergent tectonic plates pulling apart; the Pacific Ring of Fire has examples of volcanoes caused by convergent tectonic plates coming together. By contrast, volcanoes are usually not created where two tectonic plates slide past one another. Volcanoes can also form where there is stretching and thinning of the Earth's crust (called "non-hotspot intraplate volcanism"), such as in the African Rift Valley, the Wells Gray-Clearwater volcanic field and the Rio Grande Rift in North America and the European Rhine Graben with its Eifel volcanoes.

http://en.wikipedia.org/wiki/Volcanoes

What Is An Iceberg?

2009-09-07T06:57:00.001-07:00

An iceberg is a piece of glacier that has broken off, at the edge, which touches the sea. These huge pieces of ice lie submerged under the surface of the water.

Icebergs vary greatly in size. Smaller ones measuring from 5 to 10 metres across are called growlers. But the most common ones are those which measure over 100 metres. There are some giant icebergs also, which measure as much as 1,000 metres.

An iceberg is only eight-ninths as heavy as sea water, so that one-ninth of it sticks out above sea level and the eight-ninths are below. Some of them can weight as much as 180,000,000 tonnes. Due to the above two facts, they do not drift with the winds. Rather, they follow the ocean currents. When they reach the warmer latitudes, they melt. Those that have not, pose danger to ships.

Below Iceberg info from Wikipedia (Read More):-

An iceberg is a large piece of freshwater ice that has broken off from a snow-formed glacier or ice shelf and is floating in open water.[1] It may subsequently become frozen into pack ice. Alternatively, it may come to rest on the seabed in shallower water, causing ice scour (also known as ice gouging) or becoming an ice island.

http://en.wikipedia.org/wiki/Iceberg

What Are Fossils?

2009-09-07T06:40:00.001-07:00

There are three different kinds of fossils. The first is a part of the actual body of the organism, which has been preserved from decay and which appears just as it was originally.

The second kind is that of the cast or mould of the shape of the plant or animal has been removed.

The third kind is that of the trails of footprints that animals leave behind as they move over the soft mud or clay.

Even the fossils of tiny ants, which lived millions of years ago, can be found perfectly preserved in the amber. When water animals died, their bodies were quickly covered over by mud, which prevented decaying of the shells or skeletons, and hence were well preserved. Some fossils found encased in ice have not only the skeleton but also the flesh and skin well preserved.

Below Fossils info from Wikipedia (Read More):-

Fossils (from Latin fossus, literally "having been dug up") are the preserved remains or traces of animals, plants, and other organisms from the remote past. The totality of fossils, both discovered and undiscovered, and their placement in fossiliferous (fossil-containing) rock formations and sedimentary layers (strata) is known as the fossil record. The study of fossils across geological time, how they were formed, and the evolutionary relationships between taxa (phylogeny) are some of the most important functions of the science of paleontology. Such a preserved specimen is called a "fossil" if it is older than some minimum age, most often the arbitrary date of 10,000 years ago.[1] Hence, fossils range in age from the youngest at the start of the Holocene Epoch to the oldest from the Archaean Eon several billion years old. The observations that certain fossils were associated with certain rock strata led early geologists to recognize a geological timescale in the 19th century. The development of radiometric dating techniques in the early 20th century allowed geologists to determine the numerical or "absolute" age of the various strata and thereby the included fossils.

http://en.wikipedia.org/wiki/Fossils

How Were The Caves Formed?

2009-09-07T06:29:00.001-07:00

Caves are deep hollow places in the rocky sides of hills or cliffs. The larger ones are called caverns. Some caves were formed by the constant beating of the sea waves against the rocks. Some caves appeared under the surface of the earth. These are usually the old courses of underground streams, which have worn away the soft rocks such as limestone.

Still others were formed by the volcanic shifting of surface rocks or by eruption of hot lava. Some caves have openings through their roofs, called sink holes. Some caves have galleries in tiers or rows, one above the other. Then, there are those caves, which are formed in the limestone where water percolates down, carrying bits of lime, which builds into columns called stalagmite.

Below Caves info from Wikipedia (Read More):-

A cave or cavern is a natural underground void large enough for a human to enter. Some people suggest that the term cave should only apply to cavities that have some part that does not receive daylight; however, in popular usage, the term includes smaller spaces like sea caves, rock shelters, and grottos.

Speleology is the science of exploration and study of all aspects of caves and the environment which surrounds the caves. Exploring a cave for recreation or science may be called caving, potholing, or, in Canada and the United States, spelunking (see Caving).

http://en.wikipedia.org/wiki/Caves

How Are Mountains Formed?

2009-09-07T06:21:00.001-07:00

Depending on their 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. Examples of this kind are the Appalachian and the Alps Mountains.

Second, Dome Mountains where the rock layers were forced up by lava coming with great pressure from below the Earth’s surface. Examples of these are the Black Hills of South Dakota.

Third are the Block Mountains, which are formed as a result of breaks or faults in the Earth’s crust. Examples of such are the Sierra Nevada Range of California.

The last are Volcanic Mountains, which are made up of lava, ash and cinders poured out from within the Earth. The examples include Mount Ranier in the United States, and Fujiyama in Japan.

At the same time, Rocky Mountains were formed through all the above processes.

Below Mountains info from Wikipedia (Read More):-

A mountain is a large landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill. The adjective montane is used to describe mountainous areas and things associated with them. The study of mountains is Orology. The 50 tallest mountains in the world are in Asia.

http://en.wikipedia.org/wiki/Mountains

What Are Tidal Waves (Tsunami)?

2009-09-06T02:46:00.001-07:00

Tidal waves are not ordinary waves. They are caused by some disturbances on the ocean floor. They don’t have anything to do with wind and tides. They are known as Tsunami, which is a Japanese word.

Usually, earthquakes on the ocean floor cause these waves. An earthquake on the ocean bottom produces a shock wave that travels through the water, with the same speed as that of sound. During the earthquake, the oceans floor shifts and slides. It is this motion and the shock of the disturbance that produces tidal waves.

In the beginning, they swell or rise just like an ordinary wave. Then the sea level falls for a few minutes, as if it were a low tide. And then, suddenly the great tidal wave comes in and begins at once to move across the sea at a great speed. They are known to have speeds ranging to 700 miles per hour. They can rise up to even more than a hundred feet in the air and can be very disastrous. They wipe out hundreds of villages and bring a great loss of life and property on the coastal regions through which they pass.

Below Tsunami info from Wikipedia (Read More):-

A tsunami (津波?) (pronounced /(t)suːˈnɑːmi/) is a series of water waves (called a tsunami wave train[1]) that is caused when a large volume of a body of water, such as an ocean, is rapidly displaced. The Japanese term is literally translated into "harbor wave."

Earthquakes, volcanic eruptions and other underwater explosions (detonations of nuclear devices at sea), landslides and other mass movements, bolide impacts, and other disturbances above or below water all have the potential to generate a tsunami. Due to the immense volumes of water and energy involved, the effects of tsunamis can be devastating.

http://en.wikipedia.org/wiki/Tsunami

How Are Waves Formed?

2009-09-06T02:32:00.001-07:00

Waves are formed by the wind. The energy in the wind forms waves, which move the energy from one place to another. 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 part still moves on.

This then topples over and thus forms a breaker. The energy that formed the waves loses itself against the shoreline. The fact that there is energy in the waves can be felt if you just stand in the wave. You feel yourself being carried away.

Below Waves info from Wikipedia (Read More):-

A wave is a disturbance that propagates through space and time, usually with transference of energy. A mechanical wave is a wave that propagates or travels through a medium due to the restoring forces it produces upon deformation. There also exist waves capable of traveling through a vacuum, including electromagnetic radiation and probably[1] gravitational radiation. Waves travel and transfer energy from one point to another, often with no permanent displacement of the particles of the medium (that is, with little or no associated mass transport); they consist instead of oscillations or vibrations around almost fixed locations.

http://en.wikipedia.org/wiki/Waves

Is There Life On Mars?

2009-09-06T02:17:00.001-07:00

There is no life on Mars as we know so far. But for many years there was a lot belief that some sort of a life could be found on this planet.

There were a lot of reasons for this belief. One was that it was found that there seemed to be seasonal changes on the surface of the Mars. The life there, or if it is present, it is on some other form, which we have not been able to see.

Below Mars info from Wikipedia (Read More):-

Mars is the fourth planet from the Sun in the Solar System. The planet is named after Mars, the Roman god of war. It is also referred to as the "Red Planet" because of its reddish appearance, due to iron oxide prevalent on its surface.

Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts and polar ice caps of Earth. It is the site of Olympus Mons, the highest known mountain in the Solar System, and of Valles Marineris, the largest canyon. Furthermore, in June 2008 three articles published in Nature presented evidence of an enormous impact crater in Mars's northern hemisphere, 10,600 km long by 8,500 km wide, or roughly four times larger than the largest impact crater yet discovered, the South Pole-Aitken basin.[6][7] In addition to its geographical features, Mars’ rotational period and seasonal cycles are likewise similar to those of Earth.

http://en.wikipedia.org/wiki/Mars

How Are Various Kinds Of Clouds Formed?

2009-09-06T01:50:00.001-07:00

When the warm air, laden with moisture, rises into the sky, it cools down into water vapour. The excess moisture changes into small drops of water or bits of ice and these form clouds.

Since clouds always change their shapes and are formed at different heights and temperatures, no two clouds are alike. The highest clouds are called Noctilucent clouds. They may be made of ice.

Below Clouds info from Wikipedia (Read More):-

A cloud is a visible mass of droplets or frozen crystals suspended in the atmosphere above the surface of the Earth or another planetary body. A cloud is also a visible mass attracted by gravity, such as masses of material in space called interstellar clouds and nebulae. Clouds are studied in the nephology or cloud physics branch of meteorology.

http://en.wikipedia.org/wiki/Clouds

Why Do The Stars Shine?

2009-09-06T00:20:00.001-07:00

The shine of the stars is because of the fact that star is a ball of very hot gas, which shines by its own light. The twinkle of the stars is caused by substances in the air between the star and the Earth.

The unsteady air bends the light from the star and then it appears to twinkle. Our Sun is also a star and is neither very big nor very bright. But still, the other stars look smaller than it, because they are so distant from the Earth. By studying the differences on the spectra of the stars, the astronomers are able to know about the colour, the temperature and even the chemical composition of the stars.

Below Stars Shine info from Wikipedia (Read More):-

For most of its life, a star shines due to thermonuclear fusion in its core releasing energy that traverses the star's interior and then radiates into outer space. Almost all elements heavier than hydrogen and helium were created by fusion processes in stars. Astronomers can determine the mass, age, chemical composition and many other properties of a star by observing its spectrum, luminosity and motion through space. The total mass of a star is the principal determinant in its evolution and eventual fate. Other characteristics of a star are determined by its evolutionary history, including the diameter, rotation, movement and temperature. A plot of the temperature of many stars against their luminosities, known as a Hertzsprung-Russell diagram (H–R diagram), allows the age and evolutionary state of a star to be determined.

http://en.wikipedia.org/wiki/Stars

Which Is The Brightest Star In The Sky?

2009-09-05T10:34:00.001-07:00

The ancient Greek astronomers divided stars according to their brightness. Till the invention of the telescope, the division was only of six classes or magnitudes. Stars of the first magnitude were the brightest, and those of the sixth were the faintest.

Since the invention of the telescope, the division has gone to more than twenty. There are about 22 stars of the first magnitude, that is, the brightest stars. The brightest star of all is Sirius, which has a magnitude of –1.6, making it over 1,000 times brighter than the faintest star we can see with the naked eye. The numbers of stars increase as we go down in magnitude. There are about 1,000,000,000 stars of the 20th magnitude.

Below Sirius info from Wikipedia (Read More):-

Sirius is the brightest star in the night sky with a visual apparent magnitude of −1.46, almost twice as bright as Canopus, the next brightest star. The name Sirius is derived from the Ancient Greek Σείριος.[19] The star has the Bayer designation α Canis Majoris (α CMa, or Alpha Canis Majoris). What the naked eye perceives as a single star is actually a binary star system, consisting of a white main sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, termed Sirius B.

http://en.wikipedia.org/wiki/Sirius

What Is The Milky Way?

2009-09-05T10:23:00.001-07:00

Milky Way is the name of our galaxy, in which our Sun is only one small star, among some 3,000,000,000 stars. This galaxy is flat like a watch, and we are in the inner part. When we look up into the sky, we see a long stretch of stars, which seems like a band of jewels. These are the stars in our galaxy. In the ancient times, it was believed that it was some heavenly path or something like that.

The light from the Sun takes around 8 minutes to reach the Earth. And the light from the centre of our galaxy takes around 27,000 years to reach us. This can give us a rough idea about the bigness of the galaxy. All the stars in our galaxy are revolving around a centre. And our position in the galaxy takes around 200,000,000 years to make one revolution.

Below Milky Way info from Wikipedia (Read More):-

The Milky Way, or simply the Galaxy, is the galaxy in which the Solar System is located. It is a barred spiral galaxy that is part of the Local Group of galaxies. It is one of billions of galaxies in the observable universe.

Its name is a translation of the Latin Via Lactea, in turn translated from the Greek Γαλαξίας (Galaxias), referring to the pale band of light formed by the galactic plane as seen from Earth (see etymology of galaxy). Some sources hold that, strictly speaking, the term Milky Way should refer exclusively to the band of light that the galaxy forms in the night sky, while the galaxy should receive the full name Milky Way Galaxy, or alternatively the Galaxy.[7][8][9] However, it is unclear how widespread this convention is, and the term Milky Way is routinely used in either context.

http://en.wikipedia.org/wiki/Milky_way

How Do We Define A Constellation?

2009-09-05T09:35:00.001-07:00

A constellation is a group of stars, which seem to be forming different figures, letters, etc. at night. This term has come from the Latin words con, which means together, and Stella, which means star. The ancient Babylonians, the Greeks and the Romans gave the names of their kings, queens, heroes and animals to these constellations.

Some of the later found constellations were given the names of scientific instruments such as the Sextant, the Compass and the Microscope. Today, the astronomers recognize 88 constellations in the sky. It is not easy to make out in the sky the figures that suggested the early names. For example, Aquilla is the eagle, Canis Major and Canis Minor are the big and little dogs, but the constellations do not look like these figures.

All the constellations cannot be seen from one place or at the same period of the year. At different places and in different seasons we can see different constellations.

Below Constellation info from Wikipedia (Read More):-

In modern astronomy, constellation refers to an area of the celestial sphere, defined by exact boundaries. The term "constellation" can also be used loosely to refer to just the more prominent visible stars that seem to form a pattern in that area.

In colloquial usage, a constellation is what astronomers call an asterism: a group of celestial bodies (usually stars) that appear to form a pattern in the sky or appear visibly related to each other. Examples are Orion (which appears like a human figure with a belt, often referred to as "The Hunter"), Leo (which contains bright stars that outline the form of a lion), Scorpius (which can seem reminiscent of a scorpion), and Crux (a cross).

http://en.wikipedia.org/wiki/Constellation

Why Is The Sunset Red?

2009-09-05T09:01:00.001-07:00

It is the scattering of sunlight by the atmosphere that is the reason behind redness of sunsets and the blue colour of the sky. Sunlight, which appears as white, is actually a mixture of seven colours.

As sunlight passes through the atmosphere, the dust, clouds, it gets scattered on the way. Only red light, which is of a longer wavelength, survives this and so the setting sun is seen as a lovely red.

Below Sunset info from Wikipedia (Read More):-

Sunset is the daily disappearance of the sun below the horizon as a result of the Earth's rotation. The atmospheric conditions created by the setting of the sun, occurring before and after it disappears below the horizon, are also commonly referred to as "sunset".

In astronomy the time of sunset is defined as the moment the trailing edge of the sun's disk disappears below the horizon in the west. Due to refraction of light in the atmosphere, the ray path of the setting sun is highly distorted near the horizon making the apparent astronomical sunset occur when the sun’s disk is already about one diameter below the horizon. Sunset should not be confused with dusk, which is the moment at which darkness falls, when the sun is about eighteen degrees below the horizon. The period between the astronomical sunset and dusk is called twilight.

http://en.wikipedia.org/wiki/Sunset

Why Does The Sun Shine?

2009-09-05T08:45:00.001-07:00

Though the Sun is just a star, it appears much bigger than other stars. This is because the Sun is very much near to us, as compared to the stars, which are very, very far away when compared to our distance to the Sun. Earlier it believed that the Sun was a globe, which was burning. Now it is known that what is taking place in the Sun is nuclear reaction, that is the same action that takes place in a hydrogen bomb.

What takes place there is the conversion of matter directly into energy. A bit of matter can create a lot of energy if it is fully converted. For example, about 25g of matter can produce enough energy to melt around a million tones of rocks. And it has been calculated that just one per cent of the Sun’s mass would provide enough energy to keep it going for more than a hundred million years.

Below Sun Shine info from Wikipedia (Read More):-

Sunlight, in the broad sense, is the total spectrum of the electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the atmosphere, and the solar radiation is obvious as daylight when the Sun is above the horizon. Near the poles in summer, the days are longer and the nights are shorter or non-existent. In the winter at the poles the nights are longer and for some periods of time, sunlight may not occur at all. When the direct radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and heat. Radiant heat directly produced by the radiation of the sun is different from the increase in atmospheric temperature due to the radiative heating of the atmosphere by the sun's radiation. Sunlight may be recorded using a sunshine recorder, pyranometer or pyrheliometer. Sunlight takes about 8.3 minutes to reach the Earth. The World Meteorological Organization defines sunshine as direct irradiance from the Sun measured on the ground of at least 120 watts per square metre.

http://en.wikipedia.org/wiki/Sun_shine

What Things Are Known About The Universe?

2009-09-05T08:15:00.001-07:00

The Earth is a planet that goes round the Sun. There are other planets, their satellites, asteroids and comets that go round the Sun. All of them together are known as the Solar System. But our Sun is only one among the millions of stars that are revolving round a common centre. This group of stars is called a galaxy.

Actually there are millions of galaxies. Many of the stars are bigger and brighter than our Sun. Some of them may even have a planetary system like our solar system. Our galaxy, which is called the Milky Way, has a diameter of about 100,000 Light Years. One light year is the distance light can travel in a year, which is about 6,000,000,000,000 miles. So the diameter is 100,000 times this distance. And it has been seen that all galaxies are fast moving away from each other; in other words, the universe is expanding.

Below Universe info from Wikipedia (Read More):-

The Universe comprises everything that physically exists: the entirety of space and time, all forms of matter, energy and momentum, and the physical laws and constants that govern them. However, the term Universe may be used in slightly different contextual senses, denoting such concepts as the cosmos, the world or Nature.

Current interpretations of astronomical observations indicate that the age of the Universe is 13.73 (± 0.12) billion years,[1] and that the diameter of the observable Universe is at least 93 billion light years, or 8.80 × 1026 metres.

http://en.wikipedia.org/wiki/Universe

Why Car Racing Has Become A Popular Adventure Sport?

2009-08-26T08:46:00.001-07:00

Now a days, car racing or Formula One is one of the most exciting sport and the drivers participating in it are amongst the highest paid sport personalities in the world. Formula One, Grand Prix, the most popular form of modern era car racing began in 1950s, but the roots of Formula One is far earlier, including such pre world war II legends as Italian Tazio Nuvolari and the great German teams, Auto Union and Mercedes Benz.

The first road races are believed to take place in France, in the 1890s. In the beginning the cars were upright and heavy, road were tarred sand or wood, and races were too long.

A 1200 km road race from Paris to Bordeaux race in 1899, at a speed of 19.9 mph is regarded as the 1st proper motor race. Over the years, German technology of car making companies such as Auto Union and Mercedes Benz started arranging car racing.

Below Car Racing info from Wikipedia (Read More):-

Auto racing (also known as automobile racing, motor racing or car racing) is a motorsport involving racing cars. It is one of the world's most watched television sports.

Sports car racing is a form of circuit auto racing with automobiles that have two seats and enclosed wheels. They may be purpose-built or related to road-going sports cars.

A kind of hybrid between the purism of open-wheelers and the familiarity of touring car racing, this racing is often associated with the annual Le Mans 24 Hours endurance race. First run in 1923, it is one of the oldest motor races still in existence. Other classic but now defunct sports car races include the Italian classics the Targa Florio (1906 - 1977) and Mille Miglia (1927-1957), and the Mexican Carrera Panamericana. Most top class sports car races emphasise endurance (races are typically anywhere from 2.5 to 24 hours in length), reliability and strategy over pure speed. Longer races usually involve complex pit strategy and regular driver changes - sports car racing is seen more as a team sport than a gladiatorial individual sport and team managers like John Wyer, Tom Walkinshaw, driver-turned-constructor Henri Pescarolo, Peter Sauber and Reinhold Joest have become almost as famous as many of their drivers.

http://en.wikipedia.org/wiki/Car_racing

xa4p8y2s6n

Why Do People Love To Go For Trekking?

2009-08-26T08:26:00.001-07:00

Trekking is a method of taking a break from the daily routine through some good hard work. Trekking can be a wonderful and, at the same time, an exhausting experience. To go trekking, it requires some stamina and the spirit of adventure along with a light bag containing some food, a water bottle and a camera.

A typical trekking day starts easily at 6 in the morning. There is always a trekking guide who instructs his group about the direction to follow and precautions to be taken. The trekkers get to see beautiful landscape on their way. By the end of the day the trekkers are completely exhausted, but not at all stressed.

Below Trekking info from Wikipedia (Read More):-

The word trek has entered the English language as one of few words derived from Afrikaans. It means a long, hard journey, and is derived from the Dutch trekken (meaning to pull or haul).

Hiking is an outdoor activity which consists of walking in natural environments, often on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking have been confirmed in studies.[1] The word hiking is understood in all English-speaking countries, but there are differences in usage.

http://en.wikipedia.org/wiki/Trekking

Why Elvis Presley Is Considered To Be Immortal?

2009-08-26T08:11:00.001-07:00

The king of Rock-n-Roll, Elvis Presley was born in 1935. He rose from poverty to fame in 1950s. Elvis Presley was hugely popular with the girls wherever he performed.

Elvis Presley had a unique sound and style. He toured all over the United States to perform in various concerts. During 1960s he acted in a number of movies.

Elvis Presley gave up acting in 1969 and concentrated entirely on his music. His style of singing had a lot of variety.

Elvis Presley performed at around 1000 concerts and had sold over 1 billion music album across the world. He won over 100 gold 1 platinum awards for his albums in the U.S and is by far the most popular musician. That is how he had attained the status of ‘Immortal’.

Below Elvis Presley info from Wikipedia (Read More):-

Elvis Aaron Presley a [1][4] (January 8, 1935 – August 16, 1977) was an American singer and actor. A cultural icon, he is commonly known simply as Elvis and is also sometimes referred to as The King of Rock 'n' Roll or The King.

Presley began his career in 1954 as one of the first performers of rockabilly, an uptempo fusion of country and rhythm and blues with a strong back beat. His novel versions of existing songs, mixing "black" and "white" sounds, made him popular—and controversial[5][6][7]—as did his uninhibited stage and television performances. Presley had a versatile voice[8] and he had unusually wide success encompassing many genres, including rock and roll, gospel, blues, country, ballads and pop. To date, he has been inducted into four music halls of fame.

In the 1960s, Presley made the majority of his 31 movies, most of which were poorly reviewed but financially successful musicals.[9] In 1968, he returned to live performances in a television special,[10] which led to a string of successful tours across the U.S., notably in Las Vegas, for the remainder of his career. In 1973, Presley staged the first global live concert via satellite (Aloha from Hawaii), reaching at least one billion viewers live and an additional 500 million on delay,[11][12] and it remains the most watched broadcast by an individual entertainer in television history.

http://en.wikipedia.org/wiki/Elvis_presley

Why Do People Believed In Witches?

2009-08-26T08:02:00.001-07:00

A witch is considered to be a person having a great power and authority and this power is utilized or harming others. Usually a witch is a woman who rides about at night on a broomstick.

During earlier times people lived in ignorance and superstition thus the witch craft firmly rooted itself on the hearts of people.

Around 17th century both Roman and Catholics protestant began a witch hunt, in England professional witch finders were appointed to find these witches and hundreds of people were accused of witch craft. A male witch is known as wizard or warlock.

During early Christian times witches used to sell their souls to devil, a pagan God in return they used to get supernatural powers. Men cannot understand certain phenomena. Thus due to ignorance they believed in witch craft.

Below Witches info from Wikipedia (Read More):-

A witch (from Old English wicce f. / wicca m., also compare hag) is a practitioner of witchcraft.

Witchcraft, in various historical, anthropological, religious and mythological contexts, is the use of certain kinds of supernatural or magical powers. Witchcraft can refer to the use of such powers in order to inflict harm or damage upon members of a community or their property. Other uses of the term distinguish between bad witchcraft and good witchcraft, the latter involving the use of these powers to heal someone from bad witchcraft. The concept of witchcraft is normally treated as a cultural ideology, a means of explaining human misfortune by blaming it either on a supernatural entity or a known person in the community.

http://en.wikipedia.org/wiki/Witches

Why Do Ostrich Eat Stones?

2009-08-26T07:49:00.001-07:00

The ostrich is a strange bird. It eats stones because it is a greedy bird. It’s main food consists of plant, seeds and berries but in order to digest these, ostrich eats stones.

The ostrich is found mainly in Africa and is the biggest bird in the world. It weighs nearly 130kg. Since it has small wings it cannot fly, these wings only help to maintain the balance when it is running.

Ostrich has scanty hair on its heard and neck. The ostrich lays the largest eggs. Each egg measures 15 to 18 cms in length and 12 to 15 cm in diameter. It is considered to be the fastest running bird in the world.

It can travel 80 kms per hour and run approximately 1 km at a stretch.

Below Ostrich info from Wikipedia (Read More):-

The Ostrich, Struthio camelus, is a large flightless bird native to Africa (and formerly the Middle East). It is the only living species of its family, Struthionidae and its genus, Struthio. Ostriches share the order Struthioniformes with the Emu, kiwis, and other ratites. It is distinctive in its appearance, with a long neck and legs and the ability to run at maximum speeds of about 45mph (72km/h, the top land speed of any bird).[3] The Ostrich is the largest living species of bird and lays the largest egg of any bird.

The diet of the Ostrich mainly consists of plant matter, though it also eats insects. It lives in nomadic groups which contain between five and fifty birds. When threatened, the Ostrich will either hide itself by lying flat against the ground, or will run away. If cornered, it can attack with a kick from its powerful legs. Mating patterns differ by geographical region, but territorial males fight for a harem of two to seven females.

The Ostrich is farmed around the world, particularly for its feathers, which are decorative and are also used for feather dusters. Its skin is used for leather and its meat marketed commercially.

http://en.wikipedia.org/wiki/Ostrich

Why Do People Dance?

2009-08-26T07:39:00.001-07:00

People dance to celebrate man occasions like the birth of a baby, wedding, festivals, clubbing etc. There are different types of dance like tribal dance, folk dance, disco, ball dance, etc.

In Europe, people celebrate the beginning of summer season by dancing round the maypole.

This type of dance is done for fun where every one can join and have fun. During the 17th century the folk dances become quite popular. By 19th century ballroom dance got popularity which is still quite popular.

There is another type of dance performed exclusively for the audience which is known as ballet. It is a way by which people narrate a drama without words. It is similar to operas.

Below Dance info from Wikipedia (Read More):-

Dance (from French danser, perhaps from Frankish) is a sport and art form that generally refers to movement of the body, usually rhythmic and to music,[1] used as a form of expression, social interaction or presented in a spiritual or performance setting.

Dance may also to regarded as a form of nonverbal communication between humans, and is also performed by other animals (bee dance, patterns of behaviour such as a mating dance). Gymnastics, figure skating and synchronized swimming are sports dance disciplines, while martial arts kata are often compared to dances. Motion in inanimate objects may also be described as dances (the leaves danced in the wind), and certain musical forms or genres.

Definitions of what constitutes dance are dependent on social, cultural, aesthetic, artistic and moral constraints and range from functional movement (such as folk dance) to virtuoso techniques such as ballet. Dance can be participatory, social or performed for an audience. It can also be ceremonial, competitive or erotic. Dance movements may be without significance in themselves, such as in ballet or European folk dance, or have a gestural vocabulary/symbolic system as in many Asian dances. Dance can embody or express ideas, emotions or tell a story.

Dancing has evolved many styles. Breakdancing and Krumping are related to the hip hop culture. African dance is interpretive. Ballet, Ballroom, Waltz, and Tango are classical styles of dance while Square and the Electric Slide are forms of step dances.

http://en.wikipedia.org/wiki/Dance

Why Do We Wear Shoes?

2009-08-26T07:30:00.001-07:00

Footwear has a history that goes back many thousand years, and has long been an article of prestige. The earliest shoe is believed to have been made from grass held to foot with thongs, probably to protect the feet while walking on a rough surface.

In ancient times civilizations such as Egyptians, Chinese and Vikings used to wear shoes. There are many references of shoes in many folk tales and fairy tales. The type of shoes worn depended on the climate. In Warmer climate sandal is more popular.

Though, the requirement of fashion neglects the comfort factor. Specialized footwear for specific purpose of shoes has improved; people wear shoes to suit both comfort and fashion requirements.

Below Shoes info from Wikipedia (Read More):-

A shoe is an item of footwear evolved at first to protect the human foot and later, additionally, as an item of decoration in itself. The foot contains more bones than any other single part of the body, and has evolved over hundreds of thousands of years in relation to vastly varied terrain and climatic conditions. Together with the proprioceptive system, it is what makes possible balance and ambulation.

The majority of people did not wear shoes until recent years; shoes were not worn by most of the world's population—largely because they could not afford them. Only with the advent of mass production, making available for the first time the cheap flip-flop-type sandal, for example, has shoe-wearing become predominant.

http://en.wikipedia.org/wiki/Shoes

Why Do We Celebrate Easter?

2009-08-26T07:04:00.001-07:00

Easter is a ‘Christian Holiday’ and prior to 325 A.D it was not celebrated on fixed day. Rather, it was variously celebrated on different days of the week, including Friday, Saturday and Sunday. Easter celebrates the Resurrection of Jesus Christ on the third day of his crucifixion.

The origin of Easter dates back to the beginning of Christianity. Previously Easter was known as the Sunday of Pascha. The question of the date of Easter was solved in 325 A.D by the council of Nicaea. The council decided that Easter should fall on Sunday following the first full moon after vernal equinox. March 21 was made out to be the perfect date for spring equinox. Till then, the same date has been followed, to celebrate Easter.

Below Easter info from Wikipedia (Read More):-

Easter (Greek: Πάσχα, Pascha) is the most important annual religious feast in the Christian liturgical year.[1] According to Christian scripture, Jesus was resurrected from the dead on the third day from his crucifixion. Christians celebrate this resurrection on Easter Day or Easter Sunday[2] (also Resurrection Day or Resurrection Sunday), two days after Good Friday and three days after Maundy Thursday. The chronology of his death and resurrection is variously interpreted to be between 26 and 36 AD. Easter also refers to the season of the church year called Eastertide or the Easter Season. Traditionally the Easter Season lasted for the forty days from Easter Day until Ascension Day but now officially lasts for the fifty days until Pentecost. The first week of the Easter Season is known as Easter Week or the Octave of Easter. Easter also marks the end of Lent, a season of fasting, prayer, and penance.

Easter is linked to the Jewish Passover not only for much of its symbolism but also for its position in the calendar.

Relatively newer elements such as the Easter Bunny and Easter egg hunts have become part of the holiday's modern celebrations, and those aspects are often celebrated by many Christians and non-Christians alike. There are also some Christian denominations who do not celebrate Easter.

http://en.wikipedia.org/wiki/Easter

Why Do We Celebrate Mother’s Day?

2009-08-25T08:11:00.001-07:00

In the U.S Mother’s Day is celebrated on 2nd Sunday of May. It was first observed in Philadelphia in 1907. In England there was an annual observance called ‘The Mothering Sunday’. In the U.S in 1908 Ana Jarvis began a campaign to establish a national Mother’s Day.

She persuaded her mother’s church in Grafton, West Virginia to celebrate Mother’s Day on the death anniversary of her mother. Constant efforts were taken to get the 2nd Sunday of May recognized as official Mother’s Day.

Many other countries celebrate their own Mother’s Day at different times of the year.

Below Mother’s Day info from Wikipedia (Read More):-

The modern Mother's Day holiday was created by Anna Jarvis in Grafton, West Virginia, as a day to honor mothers and motherhood; especially within the context of families, and family relationships.[1] It is now celebrated on various days in many parts of the world, some of which have a much older tradition than the modern holiday (e.g. dating to the 16th century in the UK). Father's Day is a corresponding holiday honoring fathers.

The holiday eventually became so commercialized that many, including its founder, Anna Jarvis, considered it a "Hallmark Holiday", i.e. one with an overwhelming commercial purpose. Anna ended up opposing the holiday she had helped to create.[

http://en.wikipedia.org/wiki/Mother%27s_day

Why Chimpanzee Are Considered To Be A Special Type Of Monkeys?

2009-08-25T06:21:00.001-07:00

Since chimpanzee is the most intelligent of all the monkeys, they are considered to be a special type of monkeys.

They belong to the highest order of mammals known as primates. They have no tail. They have thirteen paris of ribs. When they grow old their hair becomes grey and the skin turns dusky. They are mostly found in Central African forests.

Chimpanzee can easily be captured and kept in zoos. Chimpanzee are very emotional and have a language by which they communicate with each other.

Below Chimpanzee info from Wikipedia (Read More):-

Chimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan where the Congo River forms the boundary between the native habitat of the two species:[2]

* Common Chimpanzee, Pan troglodytes: the better known chimpanzee lives primarily in West and Central Africa.
* Bonobo, Pan paniscus: also known as the "Pygmy Chimpanzee or Bonzi Chimpanzee", this species is found in the forests of the Democratic Republic of the Congo.

Chimpanzees are members of the Hominidae family, along with gorillas, humans, and orangutans. Chimpanzee are thought to have split from human evolution about 6 million years ago and thus the two chimpanzee species are the closest living relatives to humans, all being members of the Hominini tribe (along with extinct species of Hominina subtribe). Chimpanzees are the only known members of the Panina subtribe. The two Pan species split only about one million years ago.

http://en.wikipedia.org/wiki/Chimpanzee

Why Did Dinosaurs Become Extinct?

2009-08-25T06:03:00.001-07:00

Dinosaurs were considered to be the biggest of all the animals ever came on earth. Though they were huge still, they didn’t develop a good brain. They didn’t know how to survive and save themselves from their enemies. Some scientists even believe that they disappeared due to climate changes, even the swamps dried up and they couldn’t live on vegetation since most of these dinosaurs were vegetation.

Their food supply also disappeared. The earth started having seasons which were not fit for dinosaurs survival. So, dinosaurs could not survive.

Below Dinosaurs info from Wikipedia (Read More):-

Dinosaurs (Greek: δεινόσαυρος, deinosauros) were the dominant vertebrate animals of terrestrial ecosystems for over 160 million years, from the late Triassic period (about 230 million years ago) until the end of the Cretaceous period (65 million years ago), when most of them became extinct in the Cretaceous–Tertiary extinction event. The 10000 living species of birds may be classified as dinosaurs.

The term "dinosaur" was coined in 1842 by Sir Richard Owen and derives from Greek δεινός (deinos) "terrible, powerful, wondrous" + σαῦρος (sauros) "lizard". It is sometimes used informally to describe other prehistoric reptiles, such as the pelycosaur Dimetrodon, the winged pterosaurs, and the aquatic ichthyosaurs, plesiosaurs and mosasaurs, although none of these animals were dinosaurs. Through the first half of the 20th century, most of the scientific community believed dinosaurs to have been slow, unintelligent cold-blooded animals. Most research conducted since the 1970s, however, has supported the view that dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction. The resulting transformation in the scientific understanding of dinosaurs has gradually filtered into popular consciousness.

http://en.wikipedia.org/wiki/Dinosaur

Why Do Carnivores Animals Like Salt?

2009-08-25T05:46:00.001-07:00

Since land animals have descended from the creatures living in the sea their body fluid is still the same as before, moving to the land. As they cannot obtain salt from plants or land so they require more salt. It’s the herbivores like giraffe and mouflon etc. need more salt for the plants do not contain much salt as they are drained away by the rain water.

Carnivores animals get the salt from the body fluid of their prey. Their tongues get sore; for healing salt is rubbed on their tongues.

Below Carnivores Animals info from Wikipedia (Read More):-

A carnivore (pronounced /ˈkɑrnɪvɔər/), meaning 'meat eater' (Latin carne meaning 'flesh' and vorare meaning 'to devour'), is an animal that derives its energy and nutrient requirements from a diet consisting mainly or exclusively of vertebrate and/or invertebrate animal tissue, whether through predation or scavenging.[1][2] Animals that depend solely on animal flesh for their nutrient requirements are considered obligate carnivores while those that also consume non-animal food are considered facultative carnivores.[2] Omnivores too consume both animal and non-animal food, and apart from the more general definition, there is no clearly defined ratio of plant to animal material that would distinguish a facultative carnivore from an omnivore, or an omnivore from a facultative herbivore, for that matter.[3] A carnivore that sits at the top of the foodchain is an apex predator.

http://en.wikipedia.org/wiki/Carnivores

Why Was Robin Hood Considered To Be An Important Character In Literature?

2009-08-25T05:29:00.001-07:00

Robin Hood was a balled character, who was invented to express the poor peasants resentment and their needs.

Though stealing is considered to be wrong still Robin Hood is admired as a hero because he used to steal from the rich and give it to the poor and needy.

It is believed that he lived during the 12th century. Because of his good deed he was made a hero as he would neither let any woman get hurt nor took riches from the poor. He was considered to be a great sports person and archer. Robin Hood loved nature.

Below Robin Hood info from Wikipedia (Read More):-

Robin Hood is a hero in English folklore, a highly-skilled archer and outlaw. In particular, he is known for "stealing from the rich and giving to the poor" assisted by a group of outlaws known as his "Merry Men".[1] Robin and many of his men wore Lincoln green clothes.[2]

There are many songs and stories about him, starting in medieval times, and continuing through more modern literature, films and television series. In the earliest sources Robin Hood is a commoner, but he was often later portrayed as an aristocrat, wrongfully dispossessed of his lands and made into an outlaw.

http://en.wikipedia.org/wiki/Robin_hood

Why Do People Collect Stamps?

2009-08-25T05:20:00.001-07:00

Stamp collection is considered to be a hobby. Millions of people all over the world collect stamps. For this purpose General Post Office has been set up to help people to collect stamps. Strange stamps are considered to be valuable as they are scarce.

During 1861, the South African post office was running short of stamps; so, a local firm was ordered to print a few stamps. The local firm, by mistake printed one penny Blue instead of Red and Four penny Red in place of Blue. So, these stamps were considered to be rare. People collect such rare stamps for the posterity to see and know its history.

Below Stamp Collecting info from Wikipedia (Read More):-

Stamp collecting is the collecting of postage stamps and related objects, such as covers (envelopes or packages with stamps on them). It is one of the world's most popular hobbies, with estimates of the number of collectors ranging up to 20 million in the United States alone.

Collecting is not the same as philately, which is the study of stamps. A philatelist often does, but need not, collect the objects of study, nor is it necessary to closely study what one collects. Many casual collectors enjoy accumulating stamps without worrying about the tiny details. The creation of a large or comprehensive collection, however, may require some philatelic knowledge.

Stamp collectors are an important source of revenue for some small countries who create limited runs of elaborate stamps designed mainly to be bought by stamp collectors. The stamps produced by these countries far exceed the postal needs of the countries.[citation needed]

Some collectors have taken to philatelic investment.

http://en.wikipedia.org/wiki/Stamp_collecting

Why Are The Rhinos (Rhinoceros) Endangered?

2009-08-24T08:13:00.001-07:00

Some animal species have become extinct because they were less successful than other species, which gradually replaced them. But the number of rhinoceros has reduce due to hunting.

Poaching or illegal hunting has reduced drastically the number of black rhinos. Most of them are surviving and are conserved in national parks and wildlife sanctuaries.

The rhino is hunted specially for its horn. The rhino horn can grow up to 62 inches and fetches a good price when sold, thus making the animal endangered.

Below Rhinoceros info from Wikipedia (Read More):-

Rhinoceros (pronounced /raɪˈnɒsərəs/), often colloquially abbreviated rhino, is a name used to group five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia. Three of the five species—the Javan, Sumatran and Black Rhinoceros—are critically endangered. The Indian is endangered, with fewer than 2,700 individuals remaining in the wild. The White is registered as "vulnerable", with approximately 17,500 remaining in the wild, as reported by the International Rhino Foundation.[1][2] The Rhinoceros Beetle is named as such due to its horns, which simulate rhino's horns.

http://en.wikipedia.org/wiki/Rhinoceros

Why Do Giraffes Have Long Necks?

2009-08-24T08:03:00.001-07:00

The Giraffe is the tallest among all living animals. The strange shape has made the giraffe perfectly suitable to obtain its food.

A giraffe eats only the leaves of the plants, so its height enables it to reach the leaves on trees which grow in tropical lands where there is less grass. A giraffe’s tongue is often a foot and half long which it can use skillfully to pick the smallest leaves from the thorny plants without being pricked.

It also has a long upper lip, which helps it to wrench off many leaves at a time. If the giraffe wants to drink water from the ground, it adopts a peculiar style of spreading its legs far apart, so that it can reach down easily.

Below Giraffes info from Wikipedia (Read More):-

The giraffe (Giraffa camelopardalis) is an African even-toed ungulate mammal, the tallest of all land-living animal species, and the largest ruminant. It is covered in large, irregular patches of yellow to black fur separated by white, off-white, or dark yellowish brown background. The average mass for an adult male giraffe is 1,191 kilograms (2,630 lb) while the average mass for an adult female is 828 kilograms (1,830 lb).[3][4] It is approximately 4.3 metres (14 ft) to 5.2 metres (17 ft) tall, although the tallest male recorded stood almost 6 metres (20 ft).

http://en.wikipedia.org/wiki/Giraffes

Why Did Australia Recruit The Army To Destroy Emu?

2009-08-24T07:51:00.001-07:00

Emu is the second largest bird in the world after the ostrich in Australia. It is 1.8 meters in height. They can travel 1,000 km in one year.

They are considered to be nomads or wandering species, who move from one place to another.

They cause heavy destruction to the crops in the field.

Thus, in the year 1932, the state of Western Australia took the help of an army machine gun and destroyed them. Each time they fired, these birds got scattered and soon after a month, the so called ‘The Emu War’ was abandoned.

The Emu info from Wikipedia (Read More):-

The Emu (pronounced /ˈiːmjuː/[4][5]), Dromaius novaehollandiae, is the largest bird native to Australia and the only extant member of the genus Dromaius. It is also the second-largest extant bird in the world by height, after its ratite relative, the ostrich. The soft-feathered, brown, flightless bird reach up to 2 metres (6.6 ft) in height. The Emu is common over most of mainland Australia, although it avoids heavily populated areas, dense forest, and arid areas.[2] Emus can travel great distances at a fast, economical trot and, if necessary, can sprint at 50 km/h (31 mph) for some distance at a time.[2] They are opportunistically nomadic and may travel long distances to find food; they feed on a variety of plants and insects.

http://en.wikipedia.org/wiki/Emu

Why Do Birds Have Excellent Vision?

2009-08-24T07:35:00.001-07:00

All birds have a dominant sense of vision. In most of them, the eyes are placed so far to the side of the head that they have monocular vision, that is each eye can scan a separate area. This is an essential feature shared by all hunting creatures who depend on their vision to beware of possible danger.

Birds of prey and owls have eyes set more to the front of the head, giving a more binocular vision to judge distances. Birds also have a third eyelid, which moves sideways across the cornea and keeps it moist without interrupting their vision.

Below Birds Vision info from Wikipedia (Read More):-

Vision is the most important sense for birds, since good eyesight is essential for safe flight, and this group has a number of adaptations which give visual acuity superior to that of other vertebrate groups; a pigeon has been described as "two eyes with wings".[1] The avian eye resembles that of a reptile, but has a better-positioned lens, a feature shared with mammals. Birds have the largest eyes relative to their size within the animal kingdom, and movement is consequently limited within the eye's bony socket.[1] In addition to the two eyelids usually found in vertebrates, it is protected by a third transparent movable membrane. The eye's internal anatomy is similar to that of other vertebrates, but has a structure, the pecten oculi, unique to birds.

http://en.wikipedia.org/wiki/Bird_vision

Why Do Birds Sing?

2009-08-24T07:12:00.001-07:00

The song of birds is one of the loveliest gifts of nature. When birds sing, they are, in fact, communicating with each other. Of course, they sometimes sing as expressions of joy.

When wild birds migrate at night, they cry out. These cries keep the birds together and help the lost ones to return to the flock.

Birds don’t learn to sing, it is an inborn instinct. Some birds do learn the songs of other birds. For example, a parrot can imitate the sound which it hears.

Below Birds info from Wikipedia (Read More):-

Birds (class Aves) are winged, bipedal, endothermic (warm-blooded), vertebrate animals that lay eggs. There are around 10,000 living species, making them the most numerous tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the 5 cm (2 in) Bee Hummingbird to the 3 m (10 ft) Ostrich. The fossil record indicates that birds evolved from theropod dinosaurs during the Jurassic period, around 150–200 Ma (million years ago), and the earliest known bird is the Late Jurassic Archaeopteryx, c 155–150 Ma. Most paleontologists regard birds as the only clade of dinosaurs that survived the Cretaceous–Tertiary extinction event approximately 65.5 Ma.

Many species undertake long distance annual migrations, and many more perform shorter irregular movements. Birds are social; they communicate using visual signals and through calls and songs, and participate in social behaviours including cooperative breeding and hunting, flocking, and mobbing of predators. The vast majority of bird species are socially monogamous, usually for one breeding season at a time, sometimes for years, but rarely for life. Other species have breeding systems that are polygynous ("many females") or, rarely, polyandrous ("many males"). Eggs are usually laid in a nest and incubated by the parents. Most birds have an extended period of parental care after hatching.

http://en.wikipedia.org/wiki/Birds

Why Does The Peacock Raise Its Feathers?

2009-08-24T05:58:00.001-07:00

The display of peacock’s tail feather is one of the most spectacular sights. Greeks and Romans considered the peacock as a sacred bird. The male peacock displays its gorgeous plumage for its female, the peahen.

A peacock is 7 to 8 feet long, out of which the tail is of 3 to 4 feet. At regular intervals, there are ‘eyes’, which change colour. The longer tail, is raised and held up by the stiff quills of the shorter, true tail.

Below Peacock info from Wikipedia (Read More):-

The term peafowl can refer to the two species of bird in the genus Pavo of the pheasant family, Phasianidae. The African Congo Peafowl is placed in its own genus Afropavo. Peafowl are best known for the male's extravagant tail feathers, which it displays as part of courtship. The male is called a peacock, the female a peahen[1], though it is common to hear the female also referred to as a "peacock."

The two species are:

* Indian Peafowl, Pavo cristatus is a resident breeder in the Indian subcontinent. The peacock is designated as the national bird of India.

* Green Peafowl, Pavo muticus breeds from Burma east to Java. The IUCN lists the Green Peafowl as vulnerable to extinction due to hunting and a reduction in extent and quality of habitat.

http://en.wikipedia.org/wiki/Peacock

Why Can’t The Fish Survive Out Of Water?

2009-08-24T05:48:00.001-07:00

Fishes are adapted in such a way that they can breathe underwater. They have gills on each side of their head. These gills carry tiny blood vessels.

The fish gulp in water though their mouths and pass it out through the gills. The gills extract oxygen from the water and pass it into the fish’s blood. Thus, the fish gills have the same function as the lungs but they cannot work without water and, hence, fish cannot survive outside water.

Below Fish info from Wikipedia (Read More):-

A fish is any aquatic vertebrate animal that is typically ectothermic (or cold-blooded), covered with scales, and equipped with two sets of paired fins and several unpaired fins. Fish are abundant in the sea and in fresh water, with species being known from mountain streams (e.g., char and gudgeon) as well as in the deepest depths of the ocean (e.g., gulpers and anglerfish).

Food prepared from fish is also called fish, and it is an important food source for humans. They are harvested either from wild fisheries (see fishing) or farmed in much the same way as cattle or chickens (see aquaculture). They are also exploited by recreational fishers and fishkeepers, and are exhibited in public aquaria. Fish have had a role in many cultures through the ages, ranging from deities and religious symbols to the subjects of books and popular movies.

http://en.wikipedia.org/wiki/Fish

Why Are The Coral Reefs Protected?

2009-08-24T05:40:00.001-07:00

Coral Reefs are the marine form of rain forests. They provide shelter to thousands of species of fish and invertebrates, all living in a complex balance, which make the reef system an extremely stable environment as long as man does not intervene.

Marine biologists spend a lot of time studying the reef and make valuable discoveries. Coral reefs always face the threats of extinction. Thus, people must be educated and made aware of these reefs throughout the world.

Below Coral Reefs info from Wikipedia (Read More):-

Coral reefs are aragonite structures produced by living organisms, found in marine waters containing few nutrients. In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an exoskeleton of calcium carbonate. The accumulation of skeletal material, broken and piled up by wave action and bioeroders, produces a calcareous formation that supports the living corals and a great variety of other animal and plant life.

Coral reefs most commonly live in tropical waters, but deep water and cold water corals exist on a much smaller scale.

Globally, coral reefs are under threat from climate change, ocean acidification, overuse of reef resources, and harmful land-use practices. High nutrient levels such as those found in runoff from agricultural areas can harm reefs by encouraging excess algae growth.

http://en.wikipedia.org/wiki/Coral_Reefs

Why Do Bats Fly Only At Night?

2009-08-24T05:27:00.001-07:00

Bats are small winged creatures and doesn’t need sunlight. They swoop at night between houses and plants with surprising speed, catching the inserts.

They avoid all kinds of obstacles by quick deliberate movements. A sixth sense guides them at night and helps them to ‘see’ the dangers and avoid them in time. This sixth sense works like our modern radar. As the bat flies, it emits a series of very shrill sounds.

When some obstacle gets in its way, these ultrasonic sounds are bounced back within fraction of a second. the bat hears, recognizes, calculates and keeps the obstacle away with a flap of it’s wings.

Below Bats info from Wikipedia (Read More):-

Bats are mammals in the order Chiroptera (pronounced /kaɪˈrɒptərə/). The forelimbs of bats are developed as wings, making them the only mammals naturally capable of flight (opposed to other mammals, such as flying squirrels, gliding possums and colugos, that glide only for a distance). Bats do not flap arms like birds, instead they flap spread out hands where their fingers[2] are very long and covered with a thin membrane or patagium. Chiroptera comes from two Greek words cheir (χειρ) "hand" and pteron (πτερον) "wing."

http://en.wikipedia.org/wiki/Bats

Why Does The Chameleon Often Change Its Colour?

2009-08-24T05:06:00.001-07:00

A close relative of the lizard, chameleons are found in the whole of Africa and in some parts of Asia. It can grow up to a length of 60 cms. The most striking thing about the chameleon is the speed with which it can change its colour from white to yellow, to black, to green or to brown.

These changes occur due to the change of light and temperature of its surroundings and the condition of the animal. The chameleon does not need to camouflage because when it is hunting, it is able to deceive its prey by remaining perfectly still on a branch for hours.

It very easily catches its prey over long distances because of its sticky tongue, which can dart out up to 10 cms. Its large prominent eyes can turn 180° and each eye can move independently making it an expert hunter.

Below Chameleon info from Wikipedia (Read More):-

The family Chamaeleonidae are a distinctive and highly specialized clade of lizards. They are distinguished by their parrot-like zygodactylous feet, their separately mobile and stereoscopic eyes, their very long, highly modified, and rapidly extrudable tongues, their swaying gait, and the possession by many of a prehensile tail, crests or horns on their distinctively shaped heads, and the ability of some to change color. Uniquely adapted for climbing and visual hunting, the approximately 160 species of chameleon range from Africa, Madagascar, Spain and Portugal, across south Asia, to Sri Lanka, have been introduced to Hawaii and California, and are found in warm habitats that vary from rain forest to desert conditions.

http://en.wikipedia.org/wiki/Chameleon

Why Do The Salmons Go Upstream To Spawn?

2009-08-24T04:47:00.001-07:00

The instinct that takes the Salmon on the long trip upstream is the fact that they go to a sort of headquarters of a stream to Spawn. This helps a new Salmon to be born and grow.

When the Salmons enter fresh water, they are in better condition, but as soon as they reach the fresh water, they stop feeding.

They often search for an exact place to deposit their eggs. The young Salmons remain in fresh water for about an year and then descend from the streams and enter the salt water. Hence, the cycle begins all over again.

Below Salmon info from Wikipedia (Read More):-

Salmon is the common name for several species of fish of the family Salmonidae. Several other fish in the family are called trout; the difference is often attributed to the migratory life of the salmon as compared to the residential behaviour of trout, a distinction that holds true for the Salmo genus. Salmon live in both the Atlantic (one migratory species Salmo salar) and Pacific Oceans, as well as the Great Lakes (approximately a dozen species of the genus Oncorhynchus).

Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, there are rare species that can only survive in fresh water habitats. Folklore has it that the fish return to the exact spot where they were born to spawn; tracking studies have shown this to be true but the nature of how this memory works has long been debated.

http://en.wikipedia.org/wiki/Salmon

Why Do We Find A Lot Of Snails Usually After Rain?

2009-08-23T05:35:00.001-07:00

After a shower of rain, many snails come out among the grass and bushes.

They can be seen moving slowly among the wet vegetation. Snails need a great deal of moisture for their active life and that is why they come out after rain, but retire to their shells and bury themselves in the ground during periods of drought.

In winters, they hibernate after sealing the opening of the shell with a plug of sticky material, which keeps them away from the cold. As snails need a good amount of moisture, they also come out early in the morning when there are dew drops on the ground.

Below Snails info from Wikipedia (Read More):-

The word snail is a common name for almost all members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word snail is used in a general sense, it includes sea snails, land snails and freshwater snails.

Snails lacking a shell or having only a very small one are usually called slugs. Snails that have a broadly conical shell that is not coiled or appears not to be coiled are usually known as limpets.

Snails can be found in a wide range of environments from ditches, deserts, and the abyssal depths of the sea. Although most people are familiar with terrestrial snails, land snails are in the minority. Marine snails have much greater diversity and a greater biomass. The great majority of snail species are marine. Numerous kinds can be found in fresh water and even brackish water. Many snails are herbivorous, though a few land species and many marine species are omnivores or predatory carnivores.

http://en.wikipedia.org/wiki/Snails

Why Are Some Frogs Poisonous?

2009-08-22T20:53:00.001-07:00

All frogs are not poisonous, but some of them have a kind of venom, which they use when they are attacked by predators.

The common toad exudes poison through its skin if it is attacked. Cave toads contain a drug that can cause hallucinations if these are eaten.

The skin of some frogs and toads contains poisons, which are among the most powerful known to the humans.

Below Frogs info from Wikipedia (Read More):-

Many frogs contain mild toxins that make them unpalatable to potential predators. For example, all toads have large poison glands—the parotoid glands—located behind the eyes on the top of the head. Some frogs, such as some poison dart frogs, are especially toxic. The chemical makeup of toxins in frogs varies from irritants to hallucinogens, convulsants, nerve poisons, and vasoconstrictors. Many predators of frogs have adapted to tolerate high levels of these poisons. Others, including humans, may be severely affected.

Some frogs obtain poisons from the ants and other arthropods they eat;[8] others, such as the Australian Corroboree Frogs (Pseudophryne corroboree and Pseudophryne pengilleyi), can manufacture an alkaloid not derived from their diet.[9] Some native people of South America extract poison from the poison dart frogs and apply it to their darts for hunting,[10] although few species are toxic enough to be used for this purpose. It was previously a misconception the poison was placed on arrows rather than darts. The common name of these frogs was thus changed from "poison arrow frog" to "poison dart frog" in the early 1980s. Poisonous frogs tend to advertise their toxicity with bright colours, an adaptive strategy known as aposematism. There are at least two non-poisonous species of frogs in tropical America (Eleutherodactylus gaigei and Lithodytes lineatus) that mimic the colouration of dart poison frogs' coloration for self-protection (Batesian mimicry).

http://en.wikipedia.org/wiki/Frogs

Why Do Some Insects Have Bright Colours?

2009-08-22T20:43:00.001-07:00

Insects try to protect themselves from their enemies in many different ways. Some insects like wasps and ants have powerful stings or shower poisonous fluid on the enemies.

The housefly doesn’t sting, but since its colour resembles a wasp or a bee, its enemies are wary of it. Stick insects use camouflage. They look like the leaves and twigs among which they feed. The bright colours of some insects warn their enemies that they may be poisonous.

Below Stick Insects info from Wikipedia (Read More):-

The Phasmatodea (sometimes called Phasmida) are an order of insects, whose members are variously known as stick insects (in Europe and Australasia), walking sticks or stick-bugs (in the United States), phasmids, ghost insects and leaf insects (generally the family Phylliidae). The ordinal name is derived from the Greek "phasma" meaning an apparition or phantom, and refers to the resemblance of many species to sticks or leaves. Their natural camouflage can make them extremely difficult to spot.

http://en.wikipedia.org/wiki/Stick_insects

Why Is The Ladybird Useful To Gardeners or Farmers?

2009-08-22T20:23:00.001-07:00

Beatles are among the most harmful insects, but one exception in this family is the charming ladybird with seven spots and bright red wing-case.

It is shaped like an egg which has been cut in half length wise. Ladybird is very fond of aphid or greenfly, which attacks roses and is thus a great friend of gardeners and farmers.

Even the eggs of ladybird are deposited on plants so that when the tiny lady birds hatch out, they will feed on the greenfly. The life cycle of lady birds are only just over a month, hence in once season, several generations of ladybirds are born.

Below Ladybirds info from Wikipedia (Read More):-

Coccinellidae is a family of beetles, known variously as ladybirds (British English, Australian English, South African English), ladybugs (North American English) or lady beetles (preferred by some scientists). Lesser-used names include ladyclock, lady cow, and lady fly.[1]

They are small insects, ranging from 1 mm to 10 mm (0.04 to 0.4 inches), and are commonly yellow, orange, or scarlet with small black spots on their wing covers, with black legs, head and antennae. A very large number of species are mostly or entirely black, grey, or brown and may be difficult for non-entomologists to recognize as coccinellids (and, conversely, there are many small beetles that are easily mistaken as such, like tortoise beetles).

http://en.wikipedia.org/wiki/Ladybirds

Why Are The Spiders Not Insects?

2009-08-22T19:59:00.001-07:00

Spiders belong to the class of arachnids like the scorpions and mites. Unlike the insects, they have eight legs, eight eyes and in most cases, no wings and only two, not three, parts to their bodies.

Spiders are found everywhere in every kind of climate. They manufacture a silk with which they spin this web.

At the tip of its abdomen, there are spinning organs having holes. The silk is forced out through these holes, which becomes solid as soon as it comes in contact with air. Spiders are meat eaters, feed on insects and other spiders, which get trapped in their web.

Below Spiders info from Wikipedia (Read More):-

Spiders (order Araneae) are air-breathing chelicerate arthropods that have eight legs, and chelicerae modified into fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms[1]. Spiders are found world-wide on every continent except for Antarctica, and have become established in nearly every ecological niche with the exception of air and sea colonization. As of 2008, approximately 40,000 spider species, and 109 families have been recorded by taxonomists.[2] However, there has been confusion within the scientific community as to how all these genera should be classified, as evidenced by the over 20 different classifications that have been proposed since 1900.

http://en.wikipedia.org/wiki/Spider

Why Are Some Flowers Very Colourful?

2009-08-22T09:31:00.001-07:00

A plant reproduces through its flowers. A Flowers can contain either the male or female organ or both together.

Flowers have brightly coloured petals or sepals. The reason why flowers are so brightly coloured and perfumed is to attract insects.

Insects play a very important part in pollinating them. Some plants also produce a sugary liquid called nectar, which attracts the bees. As insects fly from flower to flower, they help to transfer the pollen to the stigma of the flower, resulting in fertilization.

Below Flowers info from Wikipedia (Read More):-

Plants can not move from one location to another, thus many flowers have evolved to attract animals to transfer pollen between individuals in dispersed populations. Flowers that are insect-pollinated are called entomophilous; literally "insect-loving" in Latin. They can be highly modified along with the pollinating insects by co-evolution. Flowers commonly have glands called nectaries on various parts that attract animals looking for nutritious nectar. Birds and bees have color vision, enabling them to seek out "colorful" flowers. Some flowers have patterns, called nectar guides, that show pollinators where to look for nectar; they may be visible only under ultraviolet light, which is visible to bees and some other insects. Flowers also attract pollinators by scent and some of those scents are pleasant to our sense of smell. Not all flower scents are appealing to humans, a number of flowers are pollinated by insects that are attracted to rotten flesh and have flowers that smell like dead animals, often called Carrion flowers including Rafflesia, the titan arum, and the North American pawpaw (Asimina triloba). Flowers pollinated by night visitors, including bats and moths, are likely to concentrate on scent to attract pollinators and most such flowers are white.

http://en.wikipedia.org/wiki/Flowers

Why Do Plants Produce Seeds?

2009-08-22T09:11:00.001-07:00

Embryo, from which a new plant grows, is is contained in a seed. The seed also contains a food stored to nourish the embryo until it develops roots and leaves.

The seed is enclosed in a tough coat to protect it from drying out. Many seeds are dispersed by the wind.

Other seeds have wings that allow them to glide and get dispersed. Some seeds are dispersed by plants and animals. Water also helps in the dispersal of seeds. All seeds help a new plant of its kind to grow.

Below Seeds info from Wikipedia (Read More):-

A seed (en-us-seed.ogg /ˈsiːd/ (help·info)), referred to as a kernel in some plants, is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant. The formation of the seed completes the process of reproduction in seed plants (started with the development of flowers and pollination), with the embryo developed from the zygote and the seed coat from the integuments of the ovule.

Seeds have been an important development in the reproduction and spread of flowering plants, relative to more primitive plants like mosses, ferns and liverworts, which do not have seeds and use other means to propagate themselves. This can be seen by the success of seed plants (both gymnosperms and angiosperms) in dominating biological niches on land, from forests to grasslands both in hot and cold climates.

http://en.wikipedia.org/wiki/Seeds

Why Do The Flowers Have So Many Varied Shapes?

2009-08-22T09:02:00.001-07:00

The reason that flowers come in so many different shapes and colours is so that they are able to fertilize.

Flowers rely on insects for pollination but it fertilizes only when an insect carries the pollen from the same plant. The shape of the flower ensures that only a certain kind of insect can pollinate it. Flat flowers like sunflower, Roses, etc. are visited by bees, whereas flowers that are tube shaped attract only insects which have long tongues.

Below Flowers info from Wikipedia (Read More):-

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Magnoliophyta, also called angiosperms). The biological function of a flower is to mediate the union of male sperm with female ovum in order to produce seeds. The process begins with pollination, is followed by fertilization, leading to the formation and dispersal of the seeds. For the higher plants, seeds are the next generation, and serve as the primary means by which individuals of a species are dispersed across the landscape. The grouping of flowers on a plant is called the inflorescence.

In addition to serving as the reproductive organs of flowering plants, flowers have long been admired and used by humans, mainly to beautify their environment but also as a source of food.

http://en.wikipedia.org/wiki/Flower

Why Is The Banana Plant Not A Tree?

2009-08-22T08:52:00.001-07:00

The banana is a giant plant, which grows from an underground tem or rhizome, and dies after producing its fruit. What looks like a trunk is in fact made of the superimposed sheaths of the large leaves.

The leaves are very fragile. The fruit initially is a flowering growth on the top of the plant but after pollination, the female flowers develop into bananas. Since each stalk lives only for a year. It has no main root.

Hence the banana is a plant and not a tree. As soon as the fruit attains full maturity, the plant dries up and dies. But, the rhizome develops fresh shoots for growth of new banana plants.

Below Banana info from Wikipedia (Read More):-

Banana is the common name for a type of fruit and also the herbaceous plants of the genus Musa which produce this commonly eaten fruit. They are native to the tropical region of Southeast Asia. Bananas are likely to have been first domesticated in Papua New Guinea.[1] Today, they are cultivated throughout the tropics.[2]

Banana plants are of the family Musaceae. They are cultivated primarily for their fruit, and to a lesser extent for the production of fibre and as ornamental plants. As the banana plants are normally tall and fairly sturdy they are often mistaken for trees, but their main or upright stem is actually a pseudostem. For some species this pseudostem can reach a height of up to 2–8 m, with leaves of up to 3.5 m in length. Each pseudostem can produce a bunch of green bananas which when ripened often turn yellow or sometimes red. A variety was even recently discovered in a rainforest in Asia that turns purple. This then dies and is replaced by another pseudostem.

http://en.wikipedia.org/wiki/Banana_tree

Why Do The Trees Have Bark?

2009-08-22T08:37:00.001-07:00

The outer portion of a woody stem is called ‘bark’. The main function of the bark is to protect the inner, delicate structures. It protects them from drying out and also from injuries. The bark is formed over the years.

Some of the outer portions become dry and die. Some of these dry pieces are shed or broken off as the tree grows larger and larger. In the palm tree, there is no clear separation between the bark and the wood.

Below Bark info from Wikipedia (Read More):-

Bark is the outermost layers of stems and roots of woody plants. Plants with bark include trees, woody vines and shrubs. Bark refers to all the tissues outside of the vascular cambium and is a nontechnical term.[1] It overlays the wood and consists of the inner bark and the outer bark. The inner bark, which in older stems is living tissue, includes the innermost area of the periderm. The outer bark in older stems, includes the dead tissue on the surface of the stems, along with parts of the innermost periderm and all the tissues on the outer side of the periderm. The outer bark on trees is also called the rhytidome. Products used by people that are derived from bark include: spices and other flavorings, tannin, resin, latex, medicines, poisons, various hallucinatory chemicals and cork. Bark has been used to make cloths, canoes, ropes and used as a surface for paintings and map making;[2] A number of plants are also grown for their attractive or interesting bark colorations and surface textures.

http://en.wikipedia.org/wiki/Bark

Why Do Cloves Make The Land Fertile?

2009-08-22T08:24:00.001-07:00

Cloves, a very important plant, are cultivated for animal food. Wherever cloves grow the soil becomes more fertile after a certain time.

The roots of this tiny plant have small nodules containing special bacteria which absorb nitrogen from the air and fix it in the soil. Thus, it makes the soil suitable for cultivation. Cloves can be easily distinguished from other grasses of the meadows.

Below Cloves info from Wikipedia (Read More):-

Cloves (Syzygium aromaticum, syn. Eugenia aromaticum or Eugenia caryophyllata) are the aromatic dried flower buds of a tree in the family Myrtaceae. Cloves are native to Indonesia and India and used as a spice in cuisine all over the world. The English name derives from Latin clavus 'nail' (also origin of French clou 'nail') as the buds vaguely resemble small irregular nails in shape. Cloves are harvested primarily in Indonesia, Madagascar, Zanzibar, Pakistan, and Sri Lanka; it is also grown in India under the name Lavang, called "lavanga" (లవంగ) in Telugu.

Cloves can be used in cooking either whole or in a ground form, but as they are extremely strong, they are used sparingly. The spice is used throughout Europe and Asia and is smoked in a type of cigarettes locally known as kretek in Indonesia. A major brand of kreteks in the United States is Djarum, which sells Djarum Black. Cloves are also an important incense material in Chinese and Japanese culture.

http://en.wikipedia.org/wiki/Clove

Why Do Cacti Have No Leaves?

2009-08-20T08:10:00.001-07:00

A cactus (plural : Cacti) plant is able to exist even in extreme conditions. For this, the plant has certain basic structures and processes. The work that is done by leaves in other plants is done by stems and branches of the Cacti.

Since leaves are absent and Cacti have spine-covered branches and stems, they are able to survive in hot dry regions. The thick skins of the stems and branches with a few pores, prevent the loss of water. The root of cacti are spread out close to the surface of the ground thus it quickly absorb water.

The water is stored in the spongy hollow stems of the cactus. The outer layer of the plant is thick and waxy, therefore prevents the water to escape.

Below Cacti info from Wikipedia (Read More):-

A cactus (plural: cacti') is any member of the plant family Cactaceae, native to the Americas. They are often used as ornamental plants, but some are also crop plants. Cacti are grown for protection of property from wild animals, as well as many other uses. Cacti are part of the plant order Caryophyllales, which also includes members like beets, gypsophila, spinach, amaranth, tumbleweeds, carnations, rhubarb, buckwheat, plumbago, bougainvillea, chickweed and knotgrass.

http://en.wikipedia.org/wiki/Cacti

Why Do Leaves Fall In Autumn Season?

2009-08-20T07:58:00.001-07:00

The sunlight becomes less during autumn season, the veins that carry sap into and out of a leaf slowly closes up. A layer of cells, known as the separation layer, develops at the base of the stem of the leaf. Slowly the leaf is separated from the tissue which is connected to the branch, and it falls.

In early autumn, due to short days and less intensity of sunlight, leaves start the processes of their fall Needles and leaves that fall doesn’t get wasted. They decompose and help the soil with nutrient forming the spongy humus layer of the forest floor which absorb the rainfall. These leaves provide food for numerous organisms found in the soil and is quite important to the ecosystem of forest.

Below Autumn Leaves info from Wikipedia (Read More):-

Autumn leaf color is a phenomenon that affects the normally green leaves of many deciduous trees and shrubs by which they take on, during a few weeks in the autumn season, one or many colors that range from red to yellow. The phenomenon is commonly called fall colors and autumn colors, while the expression fall foliage usually connotes the viewing of a tree or forest whose leaves have undergone the change. In some areas in the United States and Canada, "leaf peeping" tourism between the beginning of color changes and the onset of leaf fall, or scheduled in hope of coinciding with that period, is a major contribution to economic activity.

http://en.wikipedia.org/wiki/Autumn_leaf_color

Why Is The Seaweed Of So Many Colours?

2009-08-17T06:41:00.001-07:00

Each ocean has its own distinct varieties of seaweed. The green seaweeds are found in the shallowest parts of the sea. The brown and red varieties of seaweed grow at deeper levels. The coloured pigments of the seaweed enable them to use the sunlight. In the temperate zone the most common seaweed is the brown algae.

Along the Atlantic and Pacific coasts grows, the Kelp, another form of seaweed. Seaweeds act as fertilizers and are also a source of iodine. It is also a primary source of food for the ocean life.

Below Seaweed info from Wikipedia (Read More):-

Seaweed is a loose colloquial term encompassing macroscopic, multicellular, benthic marine algae.[1] The term includes some members of the red, brown and green algae. Seaweeds can also be classified by use (as food, medicine, fertilizer, industrial, etc.).

A seaweed may belong to one of several groups of multicellular algae: the red algae, green algae, and brown algae. As these three groups are not thought to have a common multicellular ancestor, the seaweeds are a paraphyletic group. In addition, some tuft-forming bluegreen algae (Cyanobacteria) are sometimes considered as seaweeds — "seaweed" is a colloquial term and lacks a formal definition.

http://en.wikipedia.org/wiki/Seaweed

Why Do We Remember Charles Darwin?

2009-08-17T06:22:00.001-07:00

The English scientist Charles Darwin is remembered for his ideas for evolution, which he developed after years of study and voyage of exploration.

During these explorations, he discovered that many small islands had population of unique creatures.

Darwin was able to prove how these creatures differed from their close relatives elsewhere. For example, he found a unique range of animal life in the Galapagos Islands.

Charles Darwin is remembered of his famous book ‘Origin of Species’.

Below Charles Darwin info from Wikipedia (Read More):-

Charles Robert Darwin FRS (12 February 1809 – 19 April 1882) was an English naturalist[I] who realised and presented compelling evidence that all species of life have evolved over time from common ancestors,[1][2] through the process he called natural selection. The fact that evolution occurs became accepted by the scientific community and much of the general public in his lifetime,[3] but it was not until the emergence of the modern evolutionary synthesis from the 1930s to the 1950s that a broad consensus developed that natural selection is the basic mechanism of evolution.[4] In modified form, Darwin’s scientific discovery is the unifying theory of the life sciences, explaining the diversity of life.

http://en.wikipedia.org/wiki/Charles_Darwin

Why Are Fungi Not Green In Colour?

2009-08-15T07:27:00.001-07:00

For the preparation of food, most plants make use of a special substance called chlorophyll through which water and mineral salts are absorbed from the soil, CO2 from the air and are changed into starches, needed for the plant’s growth.

This chlorophyll gives the plants their green colour. Some plants like fungi do not have chlorophyll and are to grow in the dark. Fungi grow in caves and underground places.

These plants (i.e. fungi) depend on organic substances produced by other plants. Most of the fungi do not have chlorophyll and hence are not green in colour.

Below Fungi info from Wikipedia (Read More):-

A fungus (pronounced /ˈfʌŋɡəs/) is any member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. The Fungi (pronounced /ˈfʌndʒaɪ/ or /ˈfʌŋɡaɪ/) are classified as a kingdom that is separate from plants and animals. One major difference is that fungal cells have cell walls that contain chitin, unlike the cell walls of plants, which contain cellulose. These and other differences show that the fungi form a single group of related organisms, named the Eumycota (true fungi or Eumycetes), that share a common ancestor (a monophyletic group). This fungal group is distinct from the structurally similar slime molds (myxomycetes) and water molds (oomycetes). The discipline of biology devoted to the study of fungi is known as mycology, which is often regarded as a branch of botany, even though genetic studies have shown that fungi are more closely related to animals than to plants. Fungi reproduce via spores, which are often produced on specialized structures or in fruiting bodies, such as the head of a mushroom.

http://en.wikipedia.org/wiki/Fungi

Why Do Plants Have Roots?

2009-08-15T07:15:00.001-07:00

A plant needs roots for anchoring itself to the ground and to absorb mineral salts and water from the soil. Most plants have their roots growing in the soil.

Roots regularly elongate at their tips and come in contact with new portions of the soil. Roots can be of two kinds, some plants have large, bulky roots called tap roots; some plants like grasses have fibrous roots. Fibrous roots protect soil from erosion.

There are some plants whose roots do not grow in the soil. Some tropical orchids that grow on trees have spongy roots.

Below Plant’s Root info from Wikipedia (Read More):-

In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial (growing above the ground) or aerating (growing up above the ground or especially above water). Furthermore, a stem normally occurring below ground is not exceptional either (see rhizome). So, it is better to define root as a part of a plant body that bears no leaves, and therefore also lacks nodes. There are also important internal structural differences between stems and roots. The first root that comes from a plant is called the radicle. The two major functions of roots are 1) absorption of water and inorganic nutrients and 2) anchoring of the plant body to the ground. In response to the concentration of nutrients, roots also synthesise cytokinin, which acts as a signal as to how fast the shoots can grow. Roots often function in storage of food and nutrients. The roots of most vascular plant species enter into symbiosis with certain fungi to form mycorrhizas, and a large range of other organisms including bacteria also closely associate with roots.

http://en.wikipedia.org/wiki/Plant_root

Why Are Latin Names Given To All Living Things?

2009-08-15T07:03:00.001-07:00

Most plants and animals have popular names varying from place to place.

So, such a name was required to be given that could be easily recognized everywhere.

Hence, Latin names were used for the scientific names of the living things. Carl Linnaeus was the man who established the modem scientific method of naming plants and animals.

The scientific names has two parts – the generic name, describing the group to which the living thing belongs and the specific name for that living thing only.

Below Carl Linnaeus info from Wikipedia (Read More):-

Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as sv-Carl_von_Linné.ogg Carl von Linné (help·info), May 23 [O.S. May 12] 1707 – January 10, 1778) was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology.

Linnaeus was born in the countryside of Småland, in southern Sweden. His father was the first in his ancestry to adopt a permanent last name; prior to that, ancestors had used the patronymic naming system of Scandinavian countries. His father adopted the Latin-form name Linnaeus after a giant linden tree on the family homestead. Linnaeus got most of his higher education at Uppsala University and began giving lectures of botany there in 1730. He lived abroad between 1735–1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands. He then returned to Sweden where he became professor of botany at Uppsala. In the 1740s, he was sent on several journeys through Sweden to find and classify plants and animals. In the 1750s and 60s, he continued to collect and classify animals, plants, and minerals, and published several volumes. At the time of his death, he was widely renowned throughout Europe as one of the most acclaimed scientists of the time.

http://en.wikipedia.org/wiki/Carl_Linnaeus

Why Do Nuclear Reactors Need Continuous Monitoring?

2009-08-14T09:15:00.001-07:00

The nuclear reactors are continuously monitored because when energy is released from an atom, deadly rays of radiation also come out. This radiation is very harmful when it enters the body.

This is because when too much radiation passes through living cells, it damages the cells or weakness the body’s defences against disease.

A typical nuclear power station produces a lot of waste each year, which is poured into steel tanks and then buried in concrete.

Below Nuclear Power info from Wikipedia (Read More):-

Nuclear power is any nuclear technology designed to extract usable energy from atomic nuclei via controlled nuclear reactions. The only method in use today produces power via nuclear fission, though other methods might one day include nuclear fusion and radioactive decay (see below). All utility-scale reactors[1] heat water to produce steam, which is then converted into mechanical work for the purpose of generating electricity or propulsion. In 2007, 14% of the world's electricity came from nuclear power. Also, more than 150 nuclear-powered naval vessels have been built, and a few radioisotope rockets have been produced.

http://en.wikipedia.org/wiki/Nuclear_power

Why Is Helicopter Not A Modern Discover?

2009-08-14T09:02:00.001-07:00

Leonardo Do Vinci, the famous artist, drew his plans for a helicopter hundreds of years before man actually made it.

Today’s helicopters are lifted into the air by their rotating propellers. These work like narrow wings, generating lift as they spin rapidly through air. It climbs by increasing the angle of the rotor blades. It moves forward by increasing the angle of the blade moving back on every rotation, so that it pushes against the air.

Below Helicopter info from Wikipedia (Read More):-

A helicopter is an aircraft that is lifted and propelled by one or more horizontal rotors, each rotor consisting of two or more rotor blades. Helicopters are classified as rotorcraft or rotary-wing aircraft to distinguish them from fixed-wing aircraft because the helicopter achieves lift with the rotor blades which rotate around a mast. The word 'helicopter' is adapted from the French hélicoptère, coined by Gustave de Ponton d'Amecourt in 1861, which originates from the Greek helix/helik- (ἕλικ-) = "spiral" or "turning" and pteron (πτερόν) = "wing".

The primary advantage of a helicopter is from the rotor which provides lift without the aircraft needing to move forward, allowing the helicopter to take off and land vertically without a runway. For this reason, helicopters are often used in congested or isolated areas where fixed-wing aircraft cannot take off or land. The lift from the rotor also allows the helicopter to hover in one area more efficiently than other forms of vertical takeoff and landing aircraft, allowing it to accomplish tasks that fixed-wing aircraft cannot perform.

http://en.wikipedia.org/wiki/Helicopter

Why Do We Remember Wright Brothers?

2009-08-14T08:57:00.001-07:00

People had been flying in small airships when Wright Brothers were the first ones to invent a practical aeroplane that could be flown under full control. They took the first flight in 1903 at Kitly Hawk in the United States.

The Wright biplane looked like a huge box kite, with a home-made engine that drove two propellers by means of chains. This was a successful quite unlike the earlier steam-powered aeroplane flown in 1890 by Clement Adler in France.

Below Wright Brothers info from Wikipedia (Read More):-

The Wright brothers, Orville (August 19, 1871 – January 30, 1948) and Wilbur (April 16, 1867 – May 30, 1912), were two Americans who are generally credited[1][2][3] with inventing and building the world's first successful airplane and making the first controlled, powered and sustained heavier-than-air human flight, on December 17, 1903. They are also officially credited worldwide through the Fédération Aéronautique Internationale, the standard-setting and record-keeping body for aeronautics and astronautics, as "the first sustained and controlled heavier-than-air powered flight." In the two years afterward, the brothers developed their flying machine into the first practical fixed-wing aircraft. Although not the first to build and fly experimental aircraft, the Wright brothers were the first to invent aircraft controls that made fixed-wing flight possible.

http://en.wikipedia.org/wiki/Wright_brothers

Why Has Steel Become An Important Material?

2009-08-14T08:46:00.001-07:00

Iron has a lot of carbon in it, which makes it crack very easily. If some carbon is removed, iron becomes very strong steel.

This steel is used to make tiny paper clips to skyscrapers. Steel is recyclable and can be used over and over again. Steel has become an important material, as it is the key ingredient for making cars, screws, nails, nuts and bolts, it is also used for making huge cranes and for all the construction purposes. Steel girders form the skeleton of new buildings.

Below Steel info from Wikipedia (Read More):-

Steel is an alloy consisting mostly of iron, with a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most cost-effective alloying material for iron, but various other alloying elements are used such as manganese, chromium, vanadium, and tungsten.[1] Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another. Varying the amount of alloying elements and form of their presence in the steel (solute elements, precipitated phase) controls qualities such as the hardness, ductility, and tensile strength of the resulting steel. Steel with increased carbon content can be made harder and stronger than iron, but is also more brittle.

http://en.wikipedia.org/wiki/Steel

Why Are Wind Tunnels Used?

2009-08-14T08:24:00.001-07:00

All aeroplanes are subjected to strong air pressures through the air where they move. The wings of aeroplanes have to support very high pressures during the flight, as they move though the air.

The wind tunnels have been built to reproduce the natural conditions of flight. These wind tunnels are fitted with special devices, which control the velocity, temperature and pressure of the currents of air that blows through them. These special structures have been designed to move efficiently at high speeds. Thus, the use of wind tunnels is indispensable for aircrafts.

Below Wind Tunnel info from Wikipedia (Read More):-

A wind tunnel is a research tool used in aerodynamic research. It is used to study the effects of air moving past solid objects.

Wind tunnels were first proposed as a means of studying vehicles (primarily airplanes) in free flight. The wind tunnel was envisioned as a means of reversing the usual paradigm: instead of the air's standing still and the aircraft moving at speed through it, the same effect would be obtained if the aircraft stood still and the air moved at speed past it. In that way a stationary observer could study the aircraft in action, and could measure the aerodynamic forces being imposed on the aircraft.

http://en.wikipedia.org/wiki/Wind_tunnel

Why Aerodynamic Shape Is Important For Vehicles?

2009-08-14T08:20:00.001-07:00

Anything, which moves in a gas or liquid, has its movement controlled by its shape. The slender shape of a body, which is intended to move at high speed through the air in termed aerodynamic, offering minimum resistance to the air.

Inspired by birds, man invented aerodynamic motor car in 1899 and, then, gradually came the aeroplanes, aerodynamic in shape, making transportation easy at high speed.

Below Aerodynamics info from Wikipedia (Read More):-

Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with the difference being that gas dynamics applies to all gases. Understanding the motion of air (often called a flow field) around an object enables the calculation of forces and moments acting on the object. Typical properties calculated for a flow field include velocity, pressure, density and temperature as a function of position and time. By defining a control volume around the flow field, equations for the conservation of mass, momentum, and energy can be defined and used to solve for the properties. The use of aerodynamics through mathematical analysis, empirical approximation and wind tunnel experimentation form the scientific basis for heavier-than-air flight.

http://en.wikipedia.org/wiki/Aerodynamics

Why Are Blast Furnaces Used?

2009-08-14T08:04:00.001-07:00

Iron is the most widely used metal. It is very cheap and strong, so is used to support huge building and bridges.

Through the process of smelting, which is known as reduction reaction, iron is extracted from iron ore.This process of smelting takes place in a blast furnace. The blast furnace gets its name from the hot air that is blasted into it. Here iron ore, limestone and coke (a type of carbon) are heated together and hot air is blasted into the furnace.

The carbon present in coke reacts with oxygen and forms carbon monoxide. This, in turn, takes oxygen from iron ore, leaving behind iron mixed with carbon. The temperature in a furnace reaches up to 2000°C.

Below Blast Furnaces info from Wikipedia (Read More):-

A blast furnace is a type of metallurgical furnace used for smelting to produce metals, generally iron.

In a blast furnace, fuel and ore are continuously supplied through the top of the furnace, while air (sometimes with oxygen enrichment) is blown into the bottom of the chamber, so that the chemical reactions take place throughout the furnace as the material moves downward. The end products are usually molten metal and slag phases tapped from the bottom, and flue gases exiting from the top of the furnace.

http://en.wikipedia.org/wiki/Blast_furnace

Why Do We Need Oil And Fossil Fuels?

2009-08-14T07:56:00.001-07:00

Fossil fuels, oil, coal and natural gas were formed millions of years ago, when prehistoric plants and animals died. Their decaying bodies were pressed under layers of rock and earth, and were fossilized.

The modern life, which we lead would be impossible without fossil fuels. These fuels supply heat and energy to our homes, industry and electricity.

These fossil fuels are processed to produce many other useful material like plastics, dyes and bitumen. To find out oil, test drilling is done over specific area as told by geologists.

Below Fossil Fuels info from Wikipedia (Read More):-

Fossil fuels or mineral fuels are fuels formed by natural resources such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years.[1] These fuels contain high percentage of carbon and hydrocarbons.

Fossil fuels range from volatile materials with low carbon:hydrogen ratios like methane, to liquid petroleum to nonvolatile materials composed of almost pure carbon, like anthracite coal. Methane can be found in hydrocarbon fields, alone, associated with oil, or in the form of methane clathrates. It is generally accepted that they formed from the fossilized remains of dead plants and animals[2] by exposure to heat and pressure in the Earth's crust over hundreds of millions of years.[3] This biogenic theory was first introduced by Georg Agricola in 1556 and later by Mikhail Lomonosov in the 18th century.

http://en.wikipedia.org/wiki/Fossil_fuel

Why Is It Difficult To Explore The Depths Of The Sea?

2009-08-14T07:50:00.001-07:00

Man has always been fascinated to explore the unknown, like the sea depths. Man has not met with a lot of success in this field.

The weight and pressure of water has been the greatest obstacle. As a body sinks deeper, the more it is crushed by pressure and ultimately, it becomes too huge and unbearable.

Thus, scientists are trying to build hulls, which can withstand greater pressure. Also, these bodies used for exploration have a very limited area for movement, limiting their actions.

Below Depths Of The Sea info from Wikipedia (Read More):-

Deep-sea exploration is the investigation of physical, chemical, and biological conditions on the sea bed, for scientific or commercial purposes. Deep-sea exploration is a relatively recent human activity, the depths of the sea are still a largely unexplored part of the planet earth.

Deep-sea exploration began when French scientist Pierre Simon de Laplace calculated the average depth of the Atlantic ocean, by observing tidal motions registered on Brazilian and African coasts. He determined this depth to be 13,000 ft (4,000 m). Deep-sea lifeforms were discovered in 1864 when Norwegian researchers sampled a stalked crinoid at a depth of 3,109 m (10,200 ft). More important discoveries have been made since 1870, the British Government sent out the Challenger expedition (a ship called the H.M.S. Challenger) in 1872 which discovered 715 new genera and 4,417 new species of marine organisms over the space of 4 years.

http://en.wikipedia.org/wiki/Deep-sea_exploration

Why Do We Sometimes See Rainbow In The Sky?

2009-08-14T07:43:00.001-07:00

Sunlight has the enormous speed of 300,000 km/second, covering particular wavelengths and is the sum of seven different colours.

Rainbow in the sky is a wonderful spectrum of colours. Water drops suspended in the air on which sun’s rays fall act as prisms, which break up the white light into its component colours. Thus, we frequently see a rainbow after heavy rain and storm.

Below Rainbow info from Wikipedia (Read More):-

A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere. They take the form of a multicoloured arc, with red on the outer part of the arch and violet on the inner section of the arch.

A rainbow spans a continuous spectrum of colours; the discrete bands are an artefact of human colour vision. The most commonly cited and remembered sequence, in English, is Newton's sevenfold red, orange, yellow, green, blue, indigo and violet (popularly memorized by mnemonics like Roy G. Biv). Rainbows can be caused by other forms of water than rain, including mist, spray, and dew.

http://en.wikipedia.org/wiki/Rainbow

Why Do Oil Rigs Sometimes Catch Fire?

2009-08-14T07:38:00.001-07:00

Mostly oil is found buried beneath the seabed. Oil rigs are hug floating devices that are anchored to the seabed while wells are drilled into the oil bearing rocks.

These rigs contain the drilling machinery and a helicopter pad for receiving supplies. When the oil is extracted from the rock, it contains a large amount of gas, which has to be burnt off at the surface. The gas, coming out of the oil well is in great force and can get ignited resulting in fire.

Fire fighters are used to put off the fire by using explosion. This explosion uses the surrounding oxygen in putting the fire out.

Below Oil Rigs info from Wikipedia (Read More):-

An offshore platform, often referred to as an oil platform or an oil rig, is a large structure used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the platform may be fixed to the ocean floor, may consist of an artificial island, or may float.

Most offshore platforms are located on the continental shelf, though with advances in technology and increasing crude oil prices, drilling and production in deeper waters has become both feasible and economically viable. A typical platform may have around thirty wellheads located on the platform and directional drilling allows reservoirs to be accessed at both different depths and at remote positions up to 5 miles (8 kilometers) from the platform.

http://en.wikipedia.org/wiki/Oil_rigs

Why Do We Need Numbers?

2009-08-12T08:56:00.001-07:00

Numbers describe the amount of things. Numbers can be expressed in words, by hand gestures or writing, using symbols or numberals.

Numbers can describe the number of objects, their positions amidst a lot of objects like 5th, 17th, etc.

Numbers also describe how many units of something there are, for example, how many kilograms (weight) or metre (length). Numbers are a convenient way of describing ideas and quantities.

Below Number info from Wikipedia (Read More):-

A number is a concept used to describe and assess quantity.

Number may also refer to:

    * Number (game), a number-guessing computer game
    * Number (magazine), a Japanese sports magazine
    * Number (manga), a manga by Tsubaki Kawori
    * Number (music), a self-contained piece of music
    * Grammatical number, a morphological grammatical category indicating the quantity of referents
    * Preferred number, a number that fits a standard guideline for choosing exact product dimensions within industrial design constraints
    * Telephone number, often referred to as simply a number
    * Number sign, a name for the symbol #

http://en.wikipedia.org/wiki/Numbers

Why Does The Lightning Flash?

2009-08-12T08:23:00.001-07:00

As the atmosphere heats and cools, it expands and contracts causing changes in pressure and air movement. Water droplets inside clouds have a positive electrical charge at the top of the cloud and a negative charge at the bottom.

When the negative charges come near enough to attract a positive charge from another cloud or the Earth, electrical energy is released, forming a flash of light. There is often a loud bang called thunder, along with lightning.

Thunder is caused when the air is heated to a tremendous temperature and gives out explosive noise when it expands suddenly. As light travels faster, we see the lightening flash before we hear the thunder.

Below Lightning Info from Wikipedia (Read More):-

Lightning is an atmospheric discharge of electricity accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms.[1] In the atmospheric electrical discharge, a leader of a bolt of lightning can travel at speeds of 60,000 m/s (130,000 mph), and can reach temperatures approaching 30,000 °C (54,000 °F), hot enough to fuse silica sand into glass channels known as fulgurites which are normally hollow and can extend some distance into the ground.[2][3] There are some 16 million lightning storms in the world every year.[4]

http://en.wikipedia.org/wiki/Lightning

Why Do The Ship’s Navigators Depend On Microwaves?

2009-08-11T08:33:00.001-07:00

Microwaves are a kind of radiation. They can easily pass though things that would block ordinary radio waves like rains and fog. Microwaves can also be focused and sent in a narrow beam, which helps in transmitting radio waves over long distances.

These microwaves are used by ships for navigation purposes. All ships have a radar screen, which uses microwave radiation to detect distant objects. The microwaves scan round in a circle and the echoes sent back produce an image on the screen, and it used for the Ship’s Navigators.

Below Navigator Info from Wikipedia (Read More):-

A navigator is the person on board a ship or aircraft responsible for its navigation. The navigator's primary responsibility is to be aware of ship or aircraft position at all times. Responsibilities include planning the journey, advising the Captain or aircraft Commander of estimated timing to destinations while en route, and ensuring hazards are avoided. The navigator is in charge of maintaining the aircraft or ship's nautical charts, nautical publications, and navigational equipment, and generally has responsibility for meteorological equipment and communications.

http://en.wikipedia.org/wiki/Navigator

Why Are Solar Panels Kept On The Roof Top?

2009-08-11T08:28:00.001-07:00

Man is always searching for new sources of energy. The sun gives out vast amounts of energy, of which only a tiny fraction reaches the Earth. If only this small part of energy is used, it would meet the world’s need of power.

Solar panels are used to harness the sun’s power. These panels are attached to the roof tops of houses to absorb the sun’s energy, used for heating domestic water supplies. In 1969, at Odeillo in France, the first solar power station was built. These power stations use solar power to generate energy and the solar panels are used to collect as much energy from the sun as possible.

Below Solar Panel info from Wikipedia (Read More):-

A photovoltaic module or photovoltaic panel is a packaged interconnected assembly of photovoltaic cells, also known as solar cells. The photovoltaic module, known more commonly as the solar panel, is then used as a component in a larger photovoltaic system to offer electricity for commercial and residential applications.

http://en.wikipedia.org/wiki/Photovoltaic_module

Why Is Electricity Transmitted At High Tension?

2009-08-11T08:21:00.001-07:00

The use of electricity has reached enormous proportions. With it, the need to transport electricity over great distances, has also risen.

This was not possible through direct current, which meant loss of power on the way.

Thus, alternating current was introduced, which could be transported over distances at the desired high voltages. This transportation of electricity uses large amount of electricity over thin wires and thus electricity is transmitted at high tension.

Below Electricity High Tension info from Wikipedia (Read More):-

Electric power transmission is the bulk transfer of electrical energy, a process in the delivery of electricity to consumers. A power transmission network typically connects power plants to multiple substations near a populated area. The wiring from substations to customers is referred to as electricity distribution, following the historic business model separating the wholesale electricity transmission business from distributors who deliver the electricity to the homes.[1] Electric power transmission allows distant energy sources (such as hydroelectric power plants) to be connected to consumers in population centers, and may allow exploitation of low-grade fuel resources such as coal that would otherwise be too costly to transport to generating facilities.

http://en.wikipedia.org/wiki/Electric_power_transmission

Why Transmission Of Intercontinental Television Is Possible?

2009-08-11T08:17:00.001-07:00

Television waves travel is straight lines and cannot be reflected from the ionosphere as the radio waves.

So, transmission of television programmes on intercontinental basis could be possible only when artificial satellites were placed in a stationary orbit around the Earth. These satellites receive and retransmit television signals.

Below Television Network info from Wikipedia (Read More):-

A television network is a distribution network for television content whereby a central operation provides programming for many television stations. Until the mid-1980s, television programming in most countries of the world was dominated by a small number of broadcast networks. Many early television networks (e.g. the BBC, NBC or CBS) evolved from earlier radio networks.

In countries where most networks broadcast identical, centrally originated content to all their stations and where most individual transmitters therefore operate only as large "repeater stations", the terms television network, television channel and television station have become interchangeable in everyday language, with only professionals in TV-related occupations continuing to make a difference between them. Within the industry, a tiering is sometimes created among groups of networks based on whether their programming is simultaneously originated from a central point, and whether the network master control has the technical and administrative capability to take over the programming of their affiliates in real-time when it deems this necessary—the most common example being breaking national news events.

http://en.wikipedia.org/wiki/Television_network

Why Is Litmus Paper Used In Chemistry?

2009-08-11T08:13:00.001-07:00

Litmus paper is one of the quickest ways to test a liquid for its acidity or basisity. Dyes called indicators show very quickly if the water is acidic or alkaline. Litmus is one such dye. Litmus paper turns red if the solution is acidic and it turns blue if the solution is alkaline.

Some vegetables like red cabbage and beetroot have this dye and they change colour during cooking. If the tap water is hard or alkaline, the vegetables will acquire a deep purplish blue colour.

Below Litmus Paper info from Wikipedia (Read More):-

Litmus is a water-soluble mixture of different dyes extracted from lichens, especially Roccella tinctoria. The mixture has CAS number 1393-92-6. It is often absorbed onto filter paper. The resulting piece of paper or solution with water becomes a pH indicator (one of the oldest), used to test materials for acidity. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic (i.e. alkaline) conditions,the color change occurring over the pH range 4.5-8.3 (at 25°C). Neutral litmus paper is purple in colour.[1] The mixture contains 10 to 15 different dyes (erythrolitmin (or erythrolein), azolitmin, spaniolitmin, leucoorcein and leucazolitmin). Pure azolitmin does show nearly the same effect as litmus.

http://en.wikipedia.org/wiki/Litmus_paper

Why Are So Many Pylons Erected?

2009-08-11T08:07:00.001-07:00

Electricity is moving energy that travels from place to place. For example, it can take energy of the burning coal as electricity in your home. Electricity is so extensively required by us in our daily lives that ways had to be found to let this energy travel.

Giant masts called pylons have been erected all over the country, which are connected by powerful electrical cables. Energy travels down these cables at about 250,000 kilometers in a second, almost at the speed of light.

Below Pylons info from Wikipedia (Read More):-

An electricity pylon or transmission tower (also known as Ironmen in Australia and hydro tower in Canada) is a tall, usually steel lattice structure used to support overhead electricity conductors for electric power transmission.

Three-phase electric power systems are used for high and extra-high voltage AC transmission lines (50 kV and above). The towers must be designed to carry three (or multiples of three) conductors. The towers are usually steel lattices or trusses (wooden structures are used in Germany and Scandinavia in some cases) and the insulators are either glass or porcelain discs or composite Insulators using Silicone Rubber or EPDM rubber material assembled in strings or long rod whose length is dependent on the line voltage and environmental conditions. One or two earth conductors (or "ground conductors") for lightning protection are often mounted at the top of each tower.

http://en.wikipedia.org/wiki/Electricity_pylon

Why Are Wind Turbines A Source Of Power?

2009-08-11T08:04:00.001-07:00

When oil, gas and coal are exhausted, man will need other sources of energy to fuel the cars and light the houses. Since electrical power production results in pollution, man has developed wind turbines. Huge windmills situated in exposed and windy areas are a common sight in parts of the country.

Strong, steady winds can turn the windmill blades. As the blades spin, they turn a shaft that generates electricity. The places where we have large group of wind turbines, are called wind farms. These windmills can power generators, which would then produce electricity in many homes.

Below Wind Turbines info from Wikipedia (Read More):-

A wind turbine is a rotating machine which converts the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill. If the mechanical energy is then converted to electricity, the machine is called a wind generator, wind power unit (WPU), or wind energy converter (WEC).

This article discusses electric power generation machinery. The windmill article discusses machines used for grain-grinding, water pumping, etc. The article on wind power describes turbine placement, economics and public concerns. The wind energy section of that article describes the distribution of wind energy over time, and how that affects wind-turbine design.

http://en.wikipedia.org/wiki/Wind_turbines

Why Are Circuit Boards Used?

2009-08-11T07:59:00.001-07:00

All modern electrical devices require a huge number of connections to join together all the small components for their efficient working.

Earlier, these connections were made by wires that had to be soldered together. The wires have now been replaced by the printed circuit board, which is effectively a picture of the wiring that works equally well. The image is photographed onto a special board covered by a thin copper layer.

Chemicals are used to dissolve the copper and it leaves behind a thin film of metal bands to which all the components can be attached. These circuit boards are very light, compact and cheaper.

Below Circuit Boards info from Wikipedia (Read More):-

A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, or traces, etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board (PWB) or etched wiring board. A PCB populated with electronic components is a printed circuit assembly (PCA), also known as a printed circuit board assembly (PCBA).

PCBs are rugged, inexpensive, and can be highly reliable. They require much more layout effort and higher initial cost than either wire-wrapped or point-to-point constructed circuits, but are much cheaper and faster for high-volume production. Much of the electronics industry's PCB design, assembly, and quality control needs are set by standards that are published by the IPC organization.

http://en.wikipedia.org/wiki/Printed_circuit_board

Why Do Scientists Wear Protective Clothing?

2009-08-11T07:55:00.001-07:00

Scientists study about many things including germs and bacteria that carry diseases. As many of these could be very dangerous if touched or even breathed in, it is essential for the scientists to wear protective clothing like masks, gloves, body and head protection. Scientists sometimes handle radioactive material, exposure to which can be fatal.

For these purposes, scientists use robots. But if human hand is needed, scientists wear protective clothing to protect themselves.

Below Protective Clothing info from Wikipedia (Read More):-

Personal protective equipment (PPE) refers to protective clothing, helmets, goggles, or other garment designed to protect the wearer's body or clothing from injury by blunt impacts, electrical hazards, heat, chemicals, and infection, for job-related occupational safety and health purposes, and in sports, martial arts, combat, etc. body armor is combat-specialized protective gear. In British legislation the term PPE does not cover items such as armour. The terms "protective gear" and "protective clothing" are in many cases interchangeable; "protective clothing" is applied to traditional categories of clothing, and "gear" is a more general term and preferably means uniquely protective categories, such as pads, guards, shields, masks, etc.

PPE can also be used to protect the working environment from pesticide application, pollution or infection from the worker (for example in a microchip factory). The protection may be important in both ways, as with the use of disposable gloves by surgeons and dentists.

http://en.wikipedia.org/wiki/Protective_clothing

Why Are Crystals Formed?

2009-08-11T07:51:00.001-07:00

Crystals are formed from dissolved substances or when molten substances cool slowly. As the solutions evaporate and the materials cool, their atoms come closer, forming a crystal.

The crystal gradually grows as the process continues. Some crystals grow into beautiful shapes with bright colours. In these crystals, atoms are arranged in regular patterns.

Below Crystals info from Wikipedia (Read More):-

A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification.

The word crystal is derived from the ancient Greek word κρ?σταλλο? (krustallos), which had the same meaning, but according to the ancient understanding of crystal. At root it means anything congealed by freezing, such as ice.[1] The word once referred particularly to quartz, or "rock crystal".

Most metals encountered in everyday life are polycrystals. Crystals are often symmetrically intergrown to form crystal twins.

http://en.wikipedia.org/wiki/Crystals

Why Have The Optical Fibres Proved Useful?

2009-08-11T07:47:00.001-07:00

An optical fibre is made up of fine strands of glass, along which pulses of light can travel. Light travels at a faster speed than electricity and it is, therefore, used in optical cables to carry communications for long distances without electrical interference.

This light travels along tiny glass fibres usually packed into huge bundles capable of carrying thousands of messages at a time. When we talk on the telephone, our voice is turned into laser light signals and sent through thin fibre glass tubes called optical fibres. Only one of these optical fibres can carry up to 150,000 different conversations.

Optical fibres are also used for ornate lighting.

Below Optical Fibres info from Wikipedia (Read More):-

An optical fiber (or fibre) is a glass or plastic fiber that carries light along its length. Fiber optics is the overlap of applied science and engineering concerned with the design and application of optical fibers. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communications. Fibers are used instead of metal wires because signals travel along them with less loss, and they are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so they can be used to carry images, thus allowing viewing in tight spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers.

http://en.wikipedia.org/wiki/Optical_fiber

Why Are Balloons Used For Astronomical Research?

2009-08-11T04:18:00.001-07:00

A few years ago, special balloons (called Aerobot) were used to carry limited astronomical instruments up to the higher strata of atmosphere.

There are made of a waterproof outer covering containing hydrogen or helium. As both these gases are lighter than air, the balloons tend to rise to great heights up to 40,000 mts.

The instruments carried up by these balloons Aerobot help to collect a great deal of information. Hence, these balloons Aerobot today have become indispensable research instruments.

Below Balloon Aerobot info from Wikipedia (Read More):-

An aerobot is an aerial robot, usually used in the context of an unmanned space probe or unmanned aerial vehicle.

While work has been done since the 1960s on robot "rovers" to explore the Moon and other worlds in the Solar system, such machines have limitations. They tend to be expensive and have limited range, and due to the communications time lags over interplanetary distances, they have to be smart enough to navigate without disabling themselves.

For planets with atmospheres of any substance, however, there is an alternative: an autonomous flying robot, or "aerobot" [1][2] Most aerobot concepts are based on aerostats, primarily balloons, but occasionally airships. Flying above obstructions in the winds, a balloon could explore large regions of a planet in great detail for relatively low cost. Airplanes for planetary exploration have also been proposed.

http://en.wikipedia.org/wiki/Aerobot

Why Are Microscopes Used By Scientists?

2009-08-11T04:15:00.001-07:00

The word microscope is made from two Greek words, micros or ‘small’ and ‘scope’ or ‘watcher’. So, it means that through microscopes, small objects can be observed.

This instrument is used to see tiny things, which are invisible to the naked eye. Today, microscope is important to man in almost every industry.

A Dutchman named Antomi Van Leiuwenhock (1632-1723) discovered the ground glass lenses with which he examined the world around him. In 1670s, he made the first crude microscope using a tiny lens.

Today, microscopes are indispensable for scientific studies and research, and are also used for medical purposes.

Below Microscope info from Wikipedia (Read More):-

A microscope (from the Greek: μικρός, mikrós, "small" and σκοπεῖν, skopeîn, "to look" or "see") is an instrument for viewing objects that are too small to be seen by the naked or unaided eye. The science of investigating small objects using such an instrument is called microscopy. The term microscopic means minute or very small, not visible with the eye unless aided by a microscope. Anton Van Leeuwenhoek's new, improved microscope allowed people to see things no human had ever seen before.

http://en.wikipedia.org/wiki/Microscope

Why Do We Study Quantum Physics?

2009-08-11T04:09:00.001-07:00

Quantum physics helps us to understand how energy is used or released by atoms. Negatively charged electronics circle around the positively charged nucleus of the atom.

They stay in the same orbit, each having its own level of energy. When, more energy is added, for example, when the atom is heated or when light shines on it, the electron jumps out to another orbit, absorbing the extra energy and drops back this energy in the form of heat or light when its returns back in it’s original orbit. This tiny packet of energy, which every atom possesses is called a ‘Quantum’.

Below Quantum info from Wikipedia (Read More):-

In physics, a quantum (plural: quanta) is an indivisible entity of a quantity that has the same units as the Planck constant and is related to both energy and momentum of elementary particles of matter (called fermions) and of photons and other bosons. The word comes from the Latin "quantus", for "how much." Behind this, one finds the fundamental notion that a physical property may be "quantized", referred to as "quantization". This means that the magnitude can take on only certain discrete numerical values, rather than any value, at least within a range. There is a related term of quantum number.

http://en.wikipedia.org/wiki/Quantum

List Of ‘Why’ Questions

2009-08-11T03:57:00.001-07:00

Why is the Pole Star so important?

Why Sky The Blue In Colour?

Why Do Maps Show North At The Top?

Why Do Days And Nights Occur?

Why Do Some Plants Survive Even In The Desert?

Why Don’t All Clouds Bring Rainfall?

Why Terracing Is Helpful For Farmers?

Why Do Houses In The Mountains Have Steep Roofs?

Why Do Seasons Occur?

Why Do Coasts Have Mild Climate?

Why Do Winds Occur?

Why Is It Foggy In Winter?

Why Does Lightning Occur During Thunderstorms?

Why Do Tides Occur?

Why Do Cyclones Occur?

Why Some Island Are Ring Shaped?

Why Does The Arctic Sea Have Icebergs?

Why Are Waves Formed In The Sea?

Why Do Volcanoes Erupt?

Why Do Seas Never Dry Up?

Why Are Lakes Of Different Size And Shapes?

Why Do We See Shooting Stars At Night?

Why Do Hot Springs Occur In Some Areas?

Why Do Eclipses Occur?

Why Do Tornadoes Occur?

Why Are There Many Extinct Volcanoes?

Why Are Dams Built?

Why Sea Beaches Are Sandy?

Why Do We Remember Gerardus Mercator?

Why Is The Sea Water Salty?

Why Is Snow White In Colour?

Why Are Water Falls Formed?

Why Can Man Walk On Two Legs?

Why Is The Human Hand Adapted To All Types Of Works?

Why Is The Brain The Most Important Part Of Our Body?

Why Is It Important To Protect The Back Of The Neck?

Why Do We Have A Skeleton?

Why Is Our Blood Red In Colour?

Why Do Arteries And Veins Differ?

Why Are X-Rays Taken?

Why Is Water Essential For Our Body?

Why Are Cells Considered Important?

Why Are Vitamins Essential For Our Body?

Why Does Our Heart Beat?

Why We Are Able To Hear Sounds?

Why Do We Get Allergies?

Why Is Exercise Useful For Us?

Why Do Some People Suffer From Asthma?

Why Are Viruses And Bacteria Different?

Why Do The Cells Have Chromosomes?

Why Do The Muscles Pain After Exercise?

Why Is The Skin Important For Our Body?

Why Are Carbohydrates Necessary For Our Body?

Why Do We Have High Temperature When We Are Ill?

Why Do We Take Antibiotics?

Why Don’t The Women Have Beards?

Why Do We All Perspire?

Why Do We Dream?

Why Do We Resemble Our Parents?

Why Do We Wake Up From Sleep?

Why Do We Feel Thirsty?

Why Is Touch An Important Sense That We Possess?

Why Do We Feel Hungry?

Why Are Some People Left Handed?

Why Do Some Of Us Wear Glasses?

Why Can We See Different Colours?

Why Is Vaccination Necessary Against Some Diseases?

Why Are Atoms Present Everywhere?

Why Do We Study Quantum Physics?

Why Are Microscopes Used By Scientists?

Why Are Balloons Used For Astronomical Research?

Why Have The Optical Fibres Proved Useful?

Why Are Crystals Formed?

Why Do Scientists Wear Protective Clothing?

Why Are Circuit Boards Used?

Why Are Wind Turbines A Source Of Power?

Why Are So Many Pylons Erected?

Why Is Litmus Paper Used In Chemistry?

Why Transmission Of Intercontinental Television Is Possible?

Why Is Electricity Transmitted At High Tension?

Why Are Solar Panels Kept On The Roof Top?

Why Do The Ship’s Navigators Depend On Microwaves?

Why Does The Lightning Flash?

Why Do We Need Numbers?

Why Are Atoms Present Everywhere?

2009-08-10T08:46:00.001-07:00

Atoms are tiny particles that comprise the whole universe. These tiny atoms have enormous amount of energy. Atoms are the tiniest particles into which a substance can be divided without changing into something else.

Atoms actually consist of open spaces in which tiny particles orbit move around the nucleus. These particles travel so fast that they look like solid. The smallest particle of a substance contain about one million billion atoms and these can be seen individually under very powerful electron microscopes.

Below Atoms info from Wikipedia (Read More):-

The atom is a basic unit of matter consisting of a dense, central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons (except in the case of hydrogen-1, which is the only stable nuclide with no neutron). The electrons of an atom are bound to the nucleus by the electromagnetic force. Likewise, a group of atoms can remain bound to each other, forming a molecule. An atom containing an equal number of protons and electrons is electrically neutral, otherwise it has a positive or negative charge and is an ion. An atom is classified according to the number of protons and neutrons in its nucleus: the number of protons determines the chemical element, and the number of neutrons determine the isotope of the element.

http://en.wikipedia.org/wiki/Atoms

Why Is Vaccination Necessary Against Some Diseases?

2009-08-10T08:28:00.001-07:00

In order to keep our body healthy and efficient, we should take certain prescribed vaccinations. The human body is constantly under attack by foreign bodies called Antigens.

Our body reacts spontaneously towards these attacks by producing antibodies. These wage a furious war on the antigens to neutralize them. In case of natural immunization, many times, antigens can prevail over antibodies.

In the last two centuries, a lot of vaccines have been developed for a number of diseases. The vaccinations artificially produce antibodies in our body, by way of injecting antigens in the body.

Vaccinations are done against diseases like diphtheria, typhoid, measles, small pox, etc.

Below Vaccination info from Wikipedia (Read More):-

Vaccination is the administration of antigenic material (the vaccine) to produce immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by a pathogen. Vaccination is generally considered to be the most effective and cost-effective method of preventing infectious diseases. The material administrated can either be live but weakened forms of pathogens (bacteria or viruses), killed or inactivated forms of these pathogens, or purified material such as proteins. Smallpox was the first disease people tried to prevent by purposely inoculating themselves with other types of infections; smallpox inoculation was started in China or India before 200 BC.[1] In 1718, Lady Mary Wortley Montague reported that the Turks had a habit of deliberately inoculating themselves with fluid taken from mild cases of smallpox, and that she had inoculated her own children.[2] Before 1796 when British physician Edward Jenner tested the possibility of using the cowpox vaccine as an immunisation for smallpox in humans for the first time, at least six people had done the same several years earlier: a person whose identity is unknown, England, (about 1771), Mrs. Sevel, Germany (about 1772), Mr. Jensen, Germany (about 1770), Benjamin Jesty, England, in 1774, Mrs. Rendall, England (about 1782) and Peter Plett, Germany, in 1791.

http://en.wikipedia.org/wiki/Vaccinations

Why Can We See Different Colours?

2009-08-10T08:17:00.001-07:00

The retina of our eye is packed with a layer of tiny cells called rods and cones. These cells contain coloured substances that react when light falls on them, triggering a nerve impulse.

Rods are slim cells, which can help in black and white vision. Cone cells give us colour vision. They contain different light sensitive substances that respond to either red, yellow-green or blue-violet light.

Thus, cone cells give us the coloured picture of the object we see. The cone cells only work in bright light making it difficult to see and distinguish colours in a dim light.

Below Cone Cells info from Wikipedia (Read More):-

Cone cells, or cones, are photoreceptor cells in the retina of the eye that function best in relatively bright light. The cone cells gradually become sparser towards the periphery of the retina.

A commonly cited figure of six million in the human eye was found by Osterberg[1] in 1935. Oyster's textbook (1999) cites work by Curcio et al. (1990) indicating an average closer to 4.5 million cone cells and 90 million rod cells in the human retina.[citation needed]

Cones are less sensitive to light than the rod cells in the retina (which support vision at low light levels), but allow the perception of color. They are also able to perceive finer detail and more rapid changes in images, because their response times to stimuli are faster than those of rods.[2] Because humans usually have three kinds of cones with different photopsins, which have different response curves and thus respond to variation in color in different ways, they have trichromatic vision. Being color blind can change this, and there have been reports of people with four or more types of cones, giving them tetrachromatic vision.

http://en.wikipedia.org/wiki/Cone_cells

Why Do Some Of Us Wear Glasses?

2009-08-10T08:13:00.001-07:00

If our eye is not exactly of the correct shape, or the lens cannot focus properly, a clear image is not formed on the retina. Then, we need to wear glasses to correct our vision.

For a short sighted person, a distant object appears blurred because the image is formed in front of the retina.

But, in case of a long sighted person, the image is formed behind the retina, when he is trying to see a nearby object making it appear blur.

As people get older, the lenses of their eyes grow harder and cannot change their shape to change focus. Hence, glasses are required to have a correct vision.

Below Glasses info from Wikipedia (Read More):-

Glasses (also called eyeglasses or spectacles) are frames bearing lenses worn in front of the eyes, normally for vision correction, eye protection, or for protection from UV rays.

Modern glasses are typically supported by pads on the bridge of the nose and by temples placed over the ears. Historical types include the pince-nez, monocle, lorgnette, and scissors-glasses.

Eyeglass lenses are commonly made from plastic, including CR-39 and polycarbonate. These materials reduce the danger of breakage and weigh less than glass lenses. Some plastics also have more advantageous optical properties than glass, such as better transmission of visible light and greater absorption of ultraviolet light.[1] Some plastics have a greater index of refraction than most types of glass; this is useful in the making of corrective lenses shaped to correct various vision abnormalities such as myopia, allowing thinner lenses for a given prescription. Newer plastic lenses, called izon, can also correct for the higher order aberrations that naturally occur in the surface of our eye.[citation needed] These lenses create sharper vision for the people who have problems with sight and help with the halos, starbursts, and comet-tails often associated with night time driving glare.[citation needed] Wavefront guided LASIK surgery also corrects for the higher order aberrations.

http://en.wikipedia.org/wiki/Glasses

Why Are Some People Left Handed?

2009-08-10T08:09:00.001-07:00

Our brain has right half and a left half, which function in differently. It is believed that in most cases, the left half of the brain is predominant over the right half.

This helps the right half of the body to work more skillfully. We read, write, speak and work with the left half of our brain. It makes most of us right handed too.

But in the case of left handed people, its just the opposite. The right half of the brain is predominant and the person works best with the left side of his body, making him left handed.

Below Left Handed info from Wikipedia (Read More):-

In 1998, a study suggested that approximately 7 to 10 percent of the adult population was left-handed, and that left-handedness is more common in males than females.[2] Left-handedness, in comparison to the general population, also appears to occur more frequently in both identical and fraternal twins,[3][4] and several groups of individuals with neurological disorders (such as people with epilepsy,[5] Down Syndrome,[6] autism,[7] mental retardation[8] and dyslexia). Statistically, the identical twin of a left-handed person has a 76 percent chance of being left-handed, identifying the causes as partly genetic and partly environmental.

http://en.wikipedia.org/wiki/Left-handedness

Why Do We Feel Hungry?

2009-08-10T08:06:00.001-07:00

Hunger has nothing to do with an empty stomach, as is the common belief. Hunger begins when certain nutritive materials are missing in the blood.

When blood vessels do not have these materials, a message is sent to the ‘hunger centre’ of the brain which, works like a brake on the stomach and intestine. When there is lack of food, the hunger centre makes the stomach and intestine work more actively. Thus, we often her our stomach rumbling. When we are hungry, our body demands nourishment.

A very calm person can live longer without food than an excited person, because protein stored up in his body is used slowly.

Below Hunger info from Wikipedia (Read More):-

Hunger is a feeling experienced when one has a desire to eat. Satiety is the absence of hunger. The often unpleasant feeling of hunger originates in the hypothalamus and is released through receptors in the liver. Although an average nourished individual can survive weeks without food intake,[1] the sensation of hunger typically begins after a couple of hours without eating and is generally considered quite uncomfortable. The sensation of hunger can often be alleviated and even mitigated entirely with the consumption of food. Hunger is also the most commonly used term to describe the social condition of people who frequently experience, or live with the threat of experiencing, the physical sensation of hunger.

http://en.wikipedia.org/wiki/Hungry

Why Is Touch An Important Sense That We Possess?

2009-08-10T08:02:00.001-07:00

Our skin continuously passes a lot of information to our brain. It monitors touch, pain, temperature and other factors that tell the brain exactly, how our body is being affected by the environment.

Without this information, we would injure ourselves continuously or accidentally.

Below Touch info from Wikipedia (Read More):-

Touch refers to one of the sensations processed by the somatosensory system, and may refer to:

    * Haptic perception, the ability to recognize objects through touch
    * Haptic communication, the study of human touching behaviour
    * Haptic technology, technology that interfaces to the user via the sense of touch

The somatosensory system is a diverse sensory system comprising the receptors and processing centres to produce the sensory modalities such as touch, temperature, proprioception (body position), and nociception (pain). The sensory receptors cover the skin and epithelia, skeletal muscles, bones and joints, internal organs, and the cardiovascular system. While touch is considered one of the five traditional senses, the impression of touch is formed from several modalities; In medicine, the colloquial term touch is usually replaced with somatic senses to better reflect the variety of mechanisms involved.

http://en.wikipedia.org/wiki/Touch

Why Do We Feel Thirsty?

2009-08-10T07:44:00.001-07:00

If we do not get anything to drink for about three weeks, we will die. When we feel thirsty, our body tells us to replenish its liquid supply. Thirst occurs by a change in the salt content of our blood.

There is a certain normal amount of salt and water present in our blood. When the balance changes by having more salt in blood, we feel thirsty.

In our brain, there is a part called ‘Thirst Centre’ which responds to the amount of salt in our blood. Whenever, there is a change in the balance, it sends messages to the back of the throat, which then travel to the brain, making us feel thirsty.

Below Thirsty info from Wikipedia (Read More):-

Thirst is the craving for fluids, resulting in the basic instinct of animals to drink. It is an essential mechanism involved in fluid balance. It arises from a lack of fluids and/or an increase in the concentration of certain osmolites such as salt. If the water volume of the body falls below a certain threshold, or the osmolite concentration becomes too high, the brain signals thirst.

Continuous dehydration can cause myriad problems, but is most often associated with neurological problems such as seizures, and renal problems.

Excessive thirst, known as polydipsia, along with excessive urination, known as polyuria, may be an indication of diabetes.

http://en.wikipedia.org/wiki/Thirsty

Why Do We Wake Up From Sleep?

2009-08-10T07:40:00.001-07:00

Picture from eHow: How to Wake up Early to Bike to Work (http://www.ehow.com/how_2192302_wake-up-early-bike-work.html)

Sometimes, we can’t resist from sleeping while at other times, we just can’t seem to sleep. What actually wakes us up is also difficult for the scientists to explain.

When we do different types of activities, we use up a lot of energy. So, the brain and the body need rest, which is provided by sleep.

The most probable reason is that while we are asleep, our body feels hungry, cold, damp, experience fear, etc. These emotions stimulate our brain and we wake up.

Below Sleep info from Wikipedia (Read More):-

Sleep is a naturally recurring state of relatively suspended sensory and motor activity in animals, characterized by total or partial unconsciousness and the nearly complete inactivity of voluntary muscles. It is distinguished from quiet wakefulness by a decreased ability to react to stimuli, and it is more easily reversible than hibernation or coma. It is observed in all mammals, including humans, all birds, and many reptiles, amphibians, and fish. In humans, other mammals, and a substantial majority of other animals that have been studied (such as some species of fish, birds, ants, and fruit flies), regular sleep is essential for survival.

http://en.wikipedia.org/wiki/Waking_up