Thursday, September 10, 2009

What Is A Snowflake?


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 (

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.

A nameless razor fusses.

How Does Iron Rust?

Iron Rust

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 (

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.

Wednesday, September 9, 2009

How Does Wind Originate?


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 (

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.

Monday, September 7, 2009

What Is An Earthquake?


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 (

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.

What Are Volcanoes?


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 (

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.

What Is An Iceberg?


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 (

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.

What Are Fossils?


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 (

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.

How Were The Caves Formed?


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 (

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).

How Are Mountains Formed?


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 (

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.

Sunday, September 6, 2009

What Are Tidal Waves (Tsunami)?

Tidal Waves

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 (

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.

How Are Waves Formed?


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 (

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.

Is There Life On Mars?


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 (

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.

How Are Various Kinds Of Clouds Formed?


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 (

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.

Why Do The Stars Shine?

Stars Shine

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 (

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.

Saturday, September 5, 2009

Which Is The Brightest Star In The Sky?


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 (

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.

What Is The Milky Way?

Milky Way

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 (

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.

How Do We Define A Constellation?


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 (

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).

Why Is The Sunset Red?


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 (

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.

Why Does The Sun Shine?

Sun Shine

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 (

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.

What Things Are Known About The Universe?


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 (

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.

Your Ad Here