What’s a Map?
A map is something that shows the whole or a part of some area. Maps are often flat, but globes are maps that show the whole earth. There are many types of maps. Maps can also show what's out in space, or what is inside a space as small as a cell in our bodies. In their simplest form, maps show how things relate to each other in a space. People have been making maps for thousands of years. People who make Maps are called Cartographers.
Orientation of maps
The term orientation refers to the relationship between directions on a map and compass directions. Most Maps are drawn with North on the Top.
Types of Maps.
Maps of the world or large areas are often either 'political' or 'physical'. The purpose of the political map is to show territorial borders; the purpose of the physical is to show features of geography such as mountains, soil type or land use. Maps can be thematic too, to show rainfall for example.
An atlas is a collection of maps, typically of Earth or a region of Earth,
Location on Earth
The earth is effectively a sphere, so how do we describe where a point is on its surface?
The most common way to locate points on the surface of the Earth is by standard, geographic coordinates called latitude and longitude. These coordinates values are measured in degrees, minutes and seconds.
Latitude, and the Equator
We can imagine the Earth as a sphere, with an axis around which it spins. The ends of the axis are the North and South Poles. The Equator is a line around the earth, an equal distance from both poles. The Equator is also the latitude line given the value of 0 degrees.
A line connecting all the points with the same latitude value is called a line of latitude. lines of latitude are parallel to the Equator, and they are sometimes also referred to as parallels. Parallels are equally spaced. There are 90 degrees of latitude going north from the Equator, and the North Pole is at 90 degrees N. There are 90 degrees to the south of the Equator, and the South Pole is at 90 degrees S.
Longitudes, and the Prime Meridian
Lines of longitude, called meridians, run perpendicular to lines of latitude, and all pass through both poles. Each longitude line is part of a great circle. There is no obvious 0-degree point for longitude, as there is for latitude. Throughout history many different starting points have been used to measure longitude. By international agreement, the meridian line through Greenwich, England, is currently given the value of 0 degrees of longitude; this meridian is referred to as the Prime Meridian. Longitude values indicate the distance between the Prime Meridian and points east or west of it on the surface of the Earth.
Do You Know?
All places on the same meridian would experience noon (or any other time of th day) at the same time. When we want to say the time is 10:00 in the morning, we say 10:00 am. What does am (and pm) stand for?? am means ante-meridian (before noon) and pm means post-meridian (after noon).
Location of DELHI, INDIA 28 40 N 77 14 E
Tuesday, September 8, 2009
Wednesday, September 2, 2009
Tuesday, August 11, 2009
Animal Homes
Animals live in a variety of different kinds of homes from holes in the ground, to caves, nests and trees. Some animals use natural habitat for their homes. Other animals build their own home. Some animals even live in other animal's homes. Let’s explore where some animals make their home.
ROCK CAVES
Many animals like the protection and shelter of rock caves for homes. A cave can provide shelter from the sun on hot days. It can also provide shelter from the wind and cold. Some caves can even provide protection from larger predators. Tigers are the largest member of the cat family. There are many types of tigers mostly living in southern continents such as Asia. They like to live in mountainous regions where caves provide shelter from the heat. Some bears, like the brown bear, like to live in mountainous areas where caves provide a good shelter. Many sea animals also like to live in caves. Animals such as the crab and sea urchin bury themselves among the rocks. The morey eel likes to live in small holes or crevices in a coral reef. They hide in these holes, and quickly emerge to grab a passing fish for food. Bats are the only mammals that can fly. Bats sleep during the day, and come out at night in search of food. Bats use echolocation, the ability to listen to sounds bouncing off objects, to help guide them in the dark and to find food. Many bats live in caves where they are sheltered from light during the day. They hang upside down hooking their feet into cracks in the roof of a cave or in a hollow tree.
Many animals like the protection and shelter of rock caves for homes. A cave can provide shelter from the sun on hot days. It can also provide shelter from the wind and cold. Some caves can even provide protection from larger predators. Tigers are the largest member of the cat family. There are many types of tigers mostly living in southern continents such as Asia. They like to live in mountainous regions where caves provide shelter from the heat. Some bears, like the brown bear, like to live in mountainous areas where caves provide a good shelter. Many sea animals also like to live in caves. Animals such as the crab and sea urchin bury themselves among the rocks. The morey eel likes to live in small holes or crevices in a coral reef. They hide in these holes, and quickly emerge to grab a passing fish for food. Bats are the only mammals that can fly. Bats sleep during the day, and come out at night in search of food. Bats use echolocation, the ability to listen to sounds bouncing off objects, to help guide them in the dark and to find food. Many bats live in caves where they are sheltered from light during the day. They hang upside down hooking their feet into cracks in the roof of a cave or in a hollow tree.
Some Animals Live in the Ground Many animals dig burrows in the ground for a home and shelter. A burrow in the ground can provide shelter from the sun on hot days. It can also provide shelter from the wind and cold. A burrow can even provide protection from larger predators. Small rodents like the gopher, ground squirrel, mole, and rabbit dig burrows in the ground, or under logs and rocks, to provide shelter. Many of these animals, like the gopher, create very extensive underground burrow systems. They connect together many entrance and exit holes with tunnels, allowing them to travel underground. Other animals including the earthworm and ants also live in the ground. The earthworm's long, slender body helps it move through moist soil. The earthworm eats and digests the soil as it moves through it. The main food of an earthworm is decomposing plants and leaves. An Earthworm is very beneficial to us as it makes the soil fertile and its’ underground passages allow rain and air to go deep in the soil.
Some Animals Live in Trees.
Many animals live in trees as a safe place away from predators on the ground. It is probably not surprising that some animals, such as birds, live in trees. Other animals that live in trees are less common than birds. Although you don't see a snake in a tree very often, some snakes live in trees. Animals often make homes in old hollowed out trees. The tree provides both shelter and protection from other animals and predators. The tree is home to many rodents such as the squirrel. The squirrel lives in many areas of the world. It is easily recognized by its bushy tail. Although some squirrels live in burrows underground, the tree squirrel makes its home in trees. Squirrels are great tree climbers. They can make leaps of 10 to 15 feet from branch to branch. In addition to being a safe place away from predators, the squirrel can collect nuts, berries and fruit for food, and store them in the
tree. Owls are large birds of prey who are best known for their hooting calls. Most owls prefer to live in wooded areas, although some owls will find a home in old church steeples or old buildings. Monkeys and chimpanzees are mammals which along with humans are port of the primate family. They have the ability to use tools, such as sticks, to help them catch bugs or to crack open nuts for food. They build their nests from branches and vines in trees. Some snakes, such as the Green Mamba of Africa, live in trees. In trees they can catch lizards, bird's eggs and small rodents for food. Nests are built by birds and other animals, as a home for themselves and especially for their eggs. Most nests are bowl-shaped and built in tree branches, on the ground, or even in buildings. They are made of twigs, leaves, and grass held together with mud or saliva.
Some Animals Live in Hives. The honeybee and bumblebee are very social insects. They live and work in large colonies, and build large nests or hives. These hives are the home for many bees. Inside the hive, the bees build a honeycomb-shaped frame with multiple cells. The cells of the honeycomb are used to store food, such as honey and pollen, or to hold eggs, larvae and pupae. Bees live in colonies, often with several hundred bees sharing the same hive or nest. The hive is usually built in the ground, in trees, or even buildings.
Worker bees collect pollen and nectar from flowers which are used to create wax to build the hive. The queen bee creates the wax in her abdomen, which she uses to build chambers or cells where she lays her eggs. The hexagonal honeycomb is one of the most sturdy and economical structures in the world.
Some Animals Live in Barns. Many domestic animals live on farms. Their home is usually a barn or some form of pen. Most animals raised on farms are used to provide milk or food, but some of them like the horse, can also be used to help with farm work. Come explore some animals that live on a farm, and that live in a barn.
Some Animals live in Webs. A spider's web is very easy to recognize. In addition to be home, the web helps the spider catch food and protect it from some predators. Spiders have the ability to produce silk from an organ in th
eir abdomen called the spinneret. The spider's web has many purposes in addition to being a place to live.
Spiders use their web to trap insects for food. Once an insect is caught, they may also use their web to tie up their victim. Spiders also lay a line of silk as they move around. They anchor the line to a surface, and use the line just like a mountain climber uses their safety rope.
Some Animals Live in Trees.
Many animals live in trees as a safe place away from predators on the ground. It is probably not surprising that some animals, such as birds, live in trees. Other animals that live in trees are less common than birds. Although you don't see a snake in a tree very often, some snakes live in trees. Animals often make homes in old hollowed out trees. The tree provides both shelter and protection from other animals and predators. The tree is home to many rodents such as the squirrel. The squirrel lives in many areas of the world. It is easily recognized by its bushy tail. Although some squirrels live in burrows underground, the tree squirrel makes its home in trees. Squirrels are great tree climbers. They can make leaps of 10 to 15 feet from branch to branch. In addition to being a safe place away from predators, the squirrel can collect nuts, berries and fruit for food, and store them in the
tree. Owls are large birds of prey who are best known for their hooting calls. Most owls prefer to live in wooded areas, although some owls will find a home in old church steeples or old buildings. Monkeys and chimpanzees are mammals which along with humans are port of the primate family. They have the ability to use tools, such as sticks, to help them catch bugs or to crack open nuts for food. They build their nests from branches and vines in trees. Some snakes, such as the Green Mamba of Africa, live in trees. In trees they can catch lizards, bird's eggs and small rodents for food. Nests are built by birds and other animals, as a home for themselves and especially for their eggs. Most nests are bowl-shaped and built in tree branches, on the ground, or even in buildings. They are made of twigs, leaves, and grass held together with mud or saliva.Some Animals Live in Hives. The honeybee and bumblebee are very social insects. They live and work in large colonies, and build large nests or hives. These hives are the home for many bees. Inside the hive, the bees build a honeycomb-shaped frame with multiple cells. The cells of the honeycomb are used to store food, such as honey and pollen, or to hold eggs, larvae and pupae. Bees live in colonies, often with several hundred bees sharing the same hive or nest. The hive is usually built in the ground, in trees, or even buildings.
Worker bees collect pollen and nectar from flowers which are used to create wax to build the hive. The queen bee creates the wax in her abdomen, which she uses to build chambers or cells where she lays her eggs. The hexagonal honeycomb is one of the most sturdy and economical structures in the world.
Some Animals Live in Barns. Many domestic animals live on farms. Their home is usually a barn or some form of pen. Most animals raised on farms are used to provide milk or food, but some of them like the horse, can also be used to help with farm work. Come explore some animals that live on a farm, and that live in a barn.
Some Animals live in Webs. A spider's web is very easy to recognize. In addition to be home, the web helps the spider catch food and protect it from some predators. Spiders have the ability to produce silk from an organ in th
eir abdomen called the spinneret. The spider's web has many purposes in addition to being a place to live.Spiders use their web to trap insects for food. Once an insect is caught, they may also use their web to tie up their victim. Spiders also lay a line of silk as they move around. They anchor the line to a surface, and use the line just like a mountain climber uses their safety rope.
Some Animals Live in Water. About two-thirds of the Earth is covered with water. This is home for many of the Earth's creatures. Many different kinds of animals live in water. A wide variety of fish live in the sea. Many types of fish live in fresh water like rivers and lakes. Other types of fish live in the salt water of the oceans and seas. The water is not only the fishes' home, but it also provides them with the food and oxygen they need to live. Although whales and dolphins live in water, they are mammals. They cannot breathe under water. They must come to the surface to breathe air. They breathe through a blowhole, or nostrils, on the top of their head. Babies are born under water, but must be pushed to the surface by the mother so the baby can take a breath.
The circulatory and respiratory systems have adapted to living in water. Whales and dolphins can dive deep in the water on a single breath.
Some Animals Live in Houses as Pets.
The circulatory and respiratory systems have adapted to living in water. Whales and dolphins can dive deep in the water on a single breath.
Some Animals Live in Houses as Pets.
The Beaver
The most prolific civil engineer and Architect among animals is the Beaver!!
Beavers are famously busy, and they turn their talents to reengineering the landscape as few other animals can. When sites are available, beavers burrow in the banks of rivers and lakes. But they also transform less suitable habitats by building dams. Felling and gnawing trees with their strong teeth and powerful jaws, they create massive log, branch, and mud structures to block streams and turn fields and forests into the large ponds that beavers love.
Domelike beaver homes, called lodges, are also constructed of branches and mud. They are often strategically located in the middle of ponds and can only be reached by underwater entrances. These dwellings are home to extended families of monogamous parents, young kits, and the yearlings born the previous spring.
Beavers are among the largest of rodents. They are herbivores and prefer to eat leaves, bark, twigs, roots, and aquatic plants.
These animals are active all winter, swimming and foraging in their ponds even when a layer of ice covers the surface.
Suggested viewing: How does a spider spins its’ web at http://animals.howstuffworks.com/arachnids/spider5.htm
How does a beaver work at:
http://www.youtube.com/watch?v=Na2HYq11yuM
Beavers are famously busy, and they turn their talents to reengineering the landscape as few other animals can. When sites are available, beavers burrow in the banks of rivers and lakes. But they also transform less suitable habitats by building dams. Felling and gnawing trees with their strong teeth and powerful jaws, they create massive log, branch, and mud structures to block streams and turn fields and forests into the large ponds that beavers love.
Domelike beaver homes, called lodges, are also constructed of branches and mud. They are often strategically located in the middle of ponds and can only be reached by underwater entrances. These dwellings are home to extended families of monogamous parents, young kits, and the yearlings born the previous spring.
Beavers are among the largest of rodents. They are herbivores and prefer to eat leaves, bark, twigs, roots, and aquatic plants.
These animals are active all winter, swimming and foraging in their ponds even when a layer of ice covers the surface.
Suggested viewing: How does a spider spins its’ web at http://animals.howstuffworks.com/arachnids/spider5.htm
How does a beaver work at:
http://www.youtube.com/watch?v=Na2HYq11yuM
Thursday, August 6, 2009
Great Rivers
Anatomy of a river
Rivers are the lifelines of our civilizations. A river usually stars from a glacier atop a mountain. Many streams join together to make a river. Smaller rivers, called Tributaries, join the main river. The sides of a river are called River banks. A river Bed is the soil under the river. Drainage Basin is the area whose rain water is collected by the river. A good way to understand what a drainage basin is to think of the area as a shallow dish, or saucer. Whenever rain falls and lands anywhere in the river basin it all runs into the lowest place in the pan, which is the river. Floodplains are the plains around the river which are flooded during rainy seasons.
Rivers usually meet the sea, at a place called the Mouth. They deposit huge amounts of eroded soils there, forming Deltas. Erosion also creates River gorges and canyons.
Great River – The Amazon.
Amazon is the greatest river in the world by a number of measures. It carries the largest amount of water – At places it is so wide that it is called the River Sea, The Amazon is the second longest river in the world. It begins as hundreds of tiny little streams high in the Andes Mountains. It is joined by over two hundred tributaries which flow into the main river. The Amazon carries more water than any of the world's rivers. Each second, between 34 and 121 million litres of water are carried into the Atlantic Ocean. This is because rain falls on more than 200 days every year.
Amazon is so big because it is situated right on the equator, where it rains almost every day. Its’ drainage basin covers the entire northern half of the continent of South America. On its course to the sea, the Amazon flows through the biggest rainforest in the world. More then a third of all species in the world live in the Amazon. It is home to a great number of Parrots, toucans, jaguars, monkeys, fish, snakes and insects.
Boto – or the River Dolphin, the deadly Piranha and the huge Anaconda all share Amazon as their home.
Great River – The Amazon.
Amazon is the greatest river in the world by a number of measures. It carries the largest amount of water – At places it is so wide that it is called the River Sea, The Amazon is the second longest river in the world. It begins as hundreds of tiny little streams high in the Andes Mountains. It is joined by over two hundred tributaries which flow into the main river. The Amazon carries more water than any of the world's rivers. Each second, between 34 and 121 million litres of water are carried into the Atlantic Ocean. This is because rain falls on more than 200 days every year.
Amazon is so big because it is situated right on the equator, where it rains almost every day. Its’ drainage basin covers the entire northern half of the continent of South America. On its course to the sea, the Amazon flows through the biggest rainforest in the world. More then a third of all species in the world live in the Amazon. It is home to a great number of Parrots, toucans, jaguars, monkeys, fish, snakes and insects.
Boto – or the River Dolphin, the deadly Piranha and the huge Anaconda all share Amazon as their home.
Our Great River- the Ganges.
The Ganges is the main river system in India. Its source is found 3000 metres high in the Himalayas, the world's highest mountains. The Ganges gets its water from the snow melting in the spring and summer months. The course of the Ganges takes it across northern India before it finally reaches its mouth in the Bay of Bengal. The mouth of the Ganges is a delta (it is the World's largest delta).
The Ganges has two main tributaries: the Jumna and the Brahmaputra. The Jumna is 1358 kilometres in length and joins the Ganges at the city of Allahabad. The Brahmaputra is 2900 kilometres long and joins the Ganges in its delta.
The Ganges is the main river system in India. Its source is found 3000 metres high in the Himalayas, the world's highest mountains. The Ganges gets its water from the snow melting in the spring and summer months. The course of the Ganges takes it across northern India before it finally reaches its mouth in the Bay of Bengal. The mouth of the Ganges is a delta (it is the World's largest delta).
The Ganges has two main tributaries: the Jumna and the Brahmaputra. The Jumna is 1358 kilometres in length and joins the Ganges at the city of Allahabad. The Brahmaputra is 2900 kilometres long and joins the Ganges in its delta.
Tuesday, July 28, 2009
Exploring our Solar System
OUR SUN
The Sun is the closest star to Earth and is the center of our solar system. A giant, spinning ball of very hot gas, the Sun is fueled by nuclear fusion reactions. The light from the Sun heats our world and makes life possible. The Sun is also an active star that displays sunspots, solar flares, etc.. These phenomena impact our near-Earth space environment and determine our "space weather." Someday, the hydrogen in the Sun will run out. A long time from now. Our star will puff up. It will eat some planets. Even the Earth! Eventually our Sun will end up as a white dwarf.
The highly rarefied area around the sun, called the corona, extends millions of kilometers into space but is visible only during a total solar eclipse (left). Temperatures in the corona are over 1,000,000 K.
What goes around the Sun:
The first thing to notice is that the solar system is mostly empty space. The planets are very small compared to the space between them. Even the dots on the diagrams above are too big to be in proper scale with respect to the sizes of the orbits.
The orbits of the planets are ellipses with the Sun at one focus, though all except Mercury are very nearly circular.
Mercury, Venus, Earth and Mars are all Rocky planets, inner planets and small planets
Jupiter, Saturn, Uranus and Neptune are gas , outer, giant planets.
The asteroid belt between Mars and Jupiter forms the boundary between the inner solar system and the outer solar system.
Mercury
Very tiny planet, only slightly bigger than Earth’s moon, has a very elliptical orbit. Has no moons.
Venus
It is the brightest object in the sky except for the Sun and the Moon. Venus is sometimes regarded as Earth's sister planet. Venus is only slightly smaller than Earth and their densities and chemical compositions are similar. But it is radically different from Earth. It may be the least hospitable place for life in the solar system.
The pressure of Venus' atmosphere at the surface is very high, composed mostly of carbon dioxide. This dense atmosphere raises Venus' surface temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is actually hotter than Mercury's despite being nearly twice as far from the Sun.
Earth
Earth, our home planet, is a beautiful blue and white ball when seen from space. The third planet from the Sun, it is the largest of the inner planets. Earth is the only planet known to support life and to have liquid water at the surface.
Mars
Mars, Earth's outer neighbor, is the fourth planet from the Sun. Mars' bright appearance and reddish color stand out in the night sky. Impressive surface features such as enormous volcanoes and valleys are frequently obscured by huge dust storms. The planet probably got this name due to its red color; Mars is sometimes referred to as the Red Planet. Olympus Mons: the largest mountain in the Solar System rising 24 km (78,000 ft.) above the surrounding plain. Early telescopic observations revealed that Mars has permanent ice caps at both poles.
Jupiter
It is the largest planet in the solar system. When approached from afar, its fantastic striped atmosphere gradually reveals intriguing clouds that move around the planet.
Saturn
Saturn, the sixth planet from the Sun, has the most spectacular set of rings in the solar system.
Uranus
Uranus, the seventh planet from the Sun, has its spin axis almost in the plane of its orbit about the Sun. This produces unusual seasons and also causes unique magnetic and electric field structures.
Neptune
Neptune, the eighth and furthest planet from the Sun, is a very cold place. Its bluish color is caused by small amounts of methane gas in its atmosphere.
Moon
The Moon was first visited by the Soviet spacecraft Luna 2 in 1959. It is the only extraterrestrial body to have been visited by humans. The first landing was on July 20, 1969. The gravitational forces between the Earth and the Moon cause some interesting effects. The most obvious is the tides.
Space Exploration:
In 1942 the German V2 was the first rocket to reach 100km from the Earth’s surface (the boundary of space).The rocket was designed by Wernher Von Braun, who later worked with NASA as the creator of the rockets that went to the moon.
In 1947, the first animals were launched into space. Fruit flies were used to study the effects of space travel on animals, and were chosen because they are more similar to humans than you might imagine!The flies travelled with a supply of corn to eat on the flight.
Albert II, was the first monkey in space. He was a Rhesus monkey, a type of monkey that originally comes from Asia. Albert went into space on 14th June, 1949 in a specially adapted American V2 rocket, that flew to a height of 83 miles from earth.
On 4th October 1957, Russia launched the first satellite into space; Sputnik 1, and the space age had properly begun!Sputnik was the first satellite in orbit around the earth. Today there are over 500 working satellites in space. Sputnik means "Satellite" in Russian.
In November 1957, the Russian space dog Laika became the first animal to orbit the earth.Laika travelled in a spacecraft known as Sputnik 2. Laika means "Barker" in Russian, and her mission helped scientists understand whether people could survive in space.
By 1959 Both American and Russian scientists were in a race to get a spacecraft to the Moon; the Russians made it first.Space-probe Luna 2 crash-landed into the moon at a speed that would kill an astronaut if one had been travelling in it! It was ten more years until a human visited the moon's surface.
On 12th April 1961, Russian Cosmonaut Yuri Gagarin became the first man in space. Gagarin's spacecraft, Vostok 1, completed one orbit of the earth, and landed about two hours after launch.Gagarin had to bail out and land using his parachute, because the Vostok 1 was designed to crash land!
In 1963 US President John F. Kennedy promised the world that the US would land men on the moon before 1970. Before they could risk people's lives, NASA sent a robot spaceship to the moon, to make sure they could land without crashing. It was called Surveyor 1, and it made the first soft landing on the Moon on 30th May 1966.
On 20th July 1969, Neil Armstrong, and then Buzz Aldrin took "one small step" and became the first men on the moon. The first words said on the moon were "the Eagle has landed". Their spaceship, Apollo 11 worked perfectly, flying them 250,000 miles to the moon, and bringing them all the way back safely to earth. Buzz was a childhood nickname - his real name was Edwin!
Two days into its journey to the moon, on 13th April 1970, Apollo 13 suffered an explosion caused by a wiring fault. Using only whatever was on board, NASA scientists and the astronauts on board improvised repairs to bring the crippled spaceship home.The mission was a successful failure: although the crew never walked on the moon at least they made it home alive!
In 1973, Russian space probe Mars 2 explored Mars, the fourth planet of the solar system.The probe was made of two parts. One part stayed in orbit for a year, sending pictures of Mars back to earth. The other was to land and explore the surface of Mars, but it was destroyed when its parachute failed to open.
Until 12th April 1981 all spacecraft were designed to be used only once. The Space Shuttle, was designed to be reused for up to 100 visits to space, in an attempt to make space travel less expensive.With five hugely powerful rocket motors, it can fly at more than 17,000 miles per hour. Six have been built.
On January 28th 1986, tragedy struck. Space Shuttle Challenger exploded shortly after launch, because of a fuel system failure. All seven astronauts on board were killed, and all shuttles were grounded for nearly three years.This shocking accident reminded the world of the dangers of space travel, and the incredible bravery of all astronauts.
In 2003, Space shutter Columbia burst into flames on its return journey, and all its’ crew members were killed. On boars was Kalpana Chawla among others.
In 2000 the first permanent crew moved into the International Space Station (ISS), where crews of astronauts have been living ever since. The ISS is a huge space station for research and space exploration that began construction in 1986 and will not be finished until 2010.
On the 28th April 2001 American millionaire Dennis Tito became the first space tourist when he paid around 20 million dollars for a ride in a Russian Soyuz spacecraft.Dennis spent a week in orbit, most of the time visiting the International Space Station. He had to train for 900 hours just to be a passenger!
Why does an astronaut wear a spacesuit?
Space is a very challenging place to explore. There is no air in space, so there is nothing to breathe. It is very cold, unless the sun is shining onto you - and then, without air to protect you, the rays of the sun would soon burn you!To survive in space you need a suit that protects your body from the heat and cold, and surrounds you with air to breathe. Space suits are pressurised, meaning they are full of air to support your body, which is why they look puffed up. A space suit is like a tiny spaceship for one. It is a very complicated machine, with air conditioning, heating, air to breathe and water to drink. It even has a built in toilet!Some space suits attach to a rocket powered backpack, which allows the astronaut wearing it to fly around in space.
The Sun is the closest star to Earth and is the center of our solar system. A giant, spinning ball of very hot gas, the Sun is fueled by nuclear fusion reactions. The light from the Sun heats our world and makes life possible. The Sun is also an active star that displays sunspots, solar flares, etc.. These phenomena impact our near-Earth space environment and determine our "space weather." Someday, the hydrogen in the Sun will run out. A long time from now. Our star will puff up. It will eat some planets. Even the Earth! Eventually our Sun will end up as a white dwarf.
The highly rarefied area around the sun, called the corona, extends millions of kilometers into space but is visible only during a total solar eclipse (left). Temperatures in the corona are over 1,000,000 K.
What goes around the Sun:
The first thing to notice is that the solar system is mostly empty space. The planets are very small compared to the space between them. Even the dots on the diagrams above are too big to be in proper scale with respect to the sizes of the orbits.
The orbits of the planets are ellipses with the Sun at one focus, though all except Mercury are very nearly circular.
Mercury, Venus, Earth and Mars are all Rocky planets, inner planets and small planets
Jupiter, Saturn, Uranus and Neptune are gas , outer, giant planets.
The asteroid belt between Mars and Jupiter forms the boundary between the inner solar system and the outer solar system.
Mercury
Very tiny planet, only slightly bigger than Earth’s moon, has a very elliptical orbit. Has no moons.
Venus
It is the brightest object in the sky except for the Sun and the Moon. Venus is sometimes regarded as Earth's sister planet. Venus is only slightly smaller than Earth and their densities and chemical compositions are similar. But it is radically different from Earth. It may be the least hospitable place for life in the solar system.
The pressure of Venus' atmosphere at the surface is very high, composed mostly of carbon dioxide. This dense atmosphere raises Venus' surface temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is actually hotter than Mercury's despite being nearly twice as far from the Sun.
Earth
Earth, our home planet, is a beautiful blue and white ball when seen from space. The third planet from the Sun, it is the largest of the inner planets. Earth is the only planet known to support life and to have liquid water at the surface.
Mars
Mars, Earth's outer neighbor, is the fourth planet from the Sun. Mars' bright appearance and reddish color stand out in the night sky. Impressive surface features such as enormous volcanoes and valleys are frequently obscured by huge dust storms. The planet probably got this name due to its red color; Mars is sometimes referred to as the Red Planet. Olympus Mons: the largest mountain in the Solar System rising 24 km (78,000 ft.) above the surrounding plain. Early telescopic observations revealed that Mars has permanent ice caps at both poles.
Jupiter
It is the largest planet in the solar system. When approached from afar, its fantastic striped atmosphere gradually reveals intriguing clouds that move around the planet.
Saturn
Saturn, the sixth planet from the Sun, has the most spectacular set of rings in the solar system.
Uranus
Uranus, the seventh planet from the Sun, has its spin axis almost in the plane of its orbit about the Sun. This produces unusual seasons and also causes unique magnetic and electric field structures.
Neptune
Neptune, the eighth and furthest planet from the Sun, is a very cold place. Its bluish color is caused by small amounts of methane gas in its atmosphere.
Moon
The Moon was first visited by the Soviet spacecraft Luna 2 in 1959. It is the only extraterrestrial body to have been visited by humans. The first landing was on July 20, 1969. The gravitational forces between the Earth and the Moon cause some interesting effects. The most obvious is the tides.
Space Exploration:
In 1942 the German V2 was the first rocket to reach 100km from the Earth’s surface (the boundary of space).The rocket was designed by Wernher Von Braun, who later worked with NASA as the creator of the rockets that went to the moon.
In 1947, the first animals were launched into space. Fruit flies were used to study the effects of space travel on animals, and were chosen because they are more similar to humans than you might imagine!The flies travelled with a supply of corn to eat on the flight.
Albert II, was the first monkey in space. He was a Rhesus monkey, a type of monkey that originally comes from Asia. Albert went into space on 14th June, 1949 in a specially adapted American V2 rocket, that flew to a height of 83 miles from earth.
On 4th October 1957, Russia launched the first satellite into space; Sputnik 1, and the space age had properly begun!Sputnik was the first satellite in orbit around the earth. Today there are over 500 working satellites in space. Sputnik means "Satellite" in Russian.
In November 1957, the Russian space dog Laika became the first animal to orbit the earth.Laika travelled in a spacecraft known as Sputnik 2. Laika means "Barker" in Russian, and her mission helped scientists understand whether people could survive in space.
By 1959 Both American and Russian scientists were in a race to get a spacecraft to the Moon; the Russians made it first.Space-probe Luna 2 crash-landed into the moon at a speed that would kill an astronaut if one had been travelling in it! It was ten more years until a human visited the moon's surface.
On 12th April 1961, Russian Cosmonaut Yuri Gagarin became the first man in space. Gagarin's spacecraft, Vostok 1, completed one orbit of the earth, and landed about two hours after launch.Gagarin had to bail out and land using his parachute, because the Vostok 1 was designed to crash land!
In 1963 US President John F. Kennedy promised the world that the US would land men on the moon before 1970. Before they could risk people's lives, NASA sent a robot spaceship to the moon, to make sure they could land without crashing. It was called Surveyor 1, and it made the first soft landing on the Moon on 30th May 1966.
On 20th July 1969, Neil Armstrong, and then Buzz Aldrin took "one small step" and became the first men on the moon. The first words said on the moon were "the Eagle has landed". Their spaceship, Apollo 11 worked perfectly, flying them 250,000 miles to the moon, and bringing them all the way back safely to earth. Buzz was a childhood nickname - his real name was Edwin!
Two days into its journey to the moon, on 13th April 1970, Apollo 13 suffered an explosion caused by a wiring fault. Using only whatever was on board, NASA scientists and the astronauts on board improvised repairs to bring the crippled spaceship home.The mission was a successful failure: although the crew never walked on the moon at least they made it home alive!
In 1973, Russian space probe Mars 2 explored Mars, the fourth planet of the solar system.The probe was made of two parts. One part stayed in orbit for a year, sending pictures of Mars back to earth. The other was to land and explore the surface of Mars, but it was destroyed when its parachute failed to open.
Until 12th April 1981 all spacecraft were designed to be used only once. The Space Shuttle, was designed to be reused for up to 100 visits to space, in an attempt to make space travel less expensive.With five hugely powerful rocket motors, it can fly at more than 17,000 miles per hour. Six have been built.
On January 28th 1986, tragedy struck. Space Shuttle Challenger exploded shortly after launch, because of a fuel system failure. All seven astronauts on board were killed, and all shuttles were grounded for nearly three years.This shocking accident reminded the world of the dangers of space travel, and the incredible bravery of all astronauts.
In 2003, Space shutter Columbia burst into flames on its return journey, and all its’ crew members were killed. On boars was Kalpana Chawla among others.
In 2000 the first permanent crew moved into the International Space Station (ISS), where crews of astronauts have been living ever since. The ISS is a huge space station for research and space exploration that began construction in 1986 and will not be finished until 2010.
On the 28th April 2001 American millionaire Dennis Tito became the first space tourist when he paid around 20 million dollars for a ride in a Russian Soyuz spacecraft.Dennis spent a week in orbit, most of the time visiting the International Space Station. He had to train for 900 hours just to be a passenger!
Why does an astronaut wear a spacesuit?
Space is a very challenging place to explore. There is no air in space, so there is nothing to breathe. It is very cold, unless the sun is shining onto you - and then, without air to protect you, the rays of the sun would soon burn you!To survive in space you need a suit that protects your body from the heat and cold, and surrounds you with air to breathe. Space suits are pressurised, meaning they are full of air to support your body, which is why they look puffed up. A space suit is like a tiny spaceship for one. It is a very complicated machine, with air conditioning, heating, air to breathe and water to drink. It even has a built in toilet!Some space suits attach to a rocket powered backpack, which allows the astronaut wearing it to fly around in space.
Tuesday, July 21, 2009
II Ramayana II
Ramayana, the greatest epic of all times, was written by Maharishi Valmiki over 2000 years ago.
Ramayana tells us the Story of Lord Rama, who came on the Earth as an incarnation of Vishnu. He was born as the son of king Dashratha and Queen Kaushalya. He was the eldest among his brothers- Bharat, Lashman and Shatrughan. He married the daughter of king Janak- Sita and was living happily in Ayodhyaya. It was then when his stepmother, Queen Kaikayi asked Dashrath to make Bharat the king and banish Rama in the forest for 14 years. Rama, being an obedient son, agreed.
His loving wife , Sita and loyal brother , Lakshman followed hin in the jungle. They lived there peacefully untill one day Suparnakha, sister of the demon king Ravana spotted them. She instantly liked the handsome Rama, and approached him. Rama rejected her. Furious, she charged towards Sita, where in Lakshman cut off her nose.
Agitated, Suparnakha went to her brother Ravana, and told him of Sita's extraordinary beauty and the brother's atrocities on her. Ravana kidnapped Sita and brought her to Lanka.
Rama and Lakshman enlisted the help of the monkey king, Sugriva and his general, Hanuman to trace Sita. Hanuman was able to locate Sita in Lanka. Soon, Rama and his monkey army invaded Lanka.
A fierce battle raged. Ravana was helped by his able son, Indrajit and mostrous brother , Kumbhkaran. His another brother Vibhishana , was good at heart, and so he changed sides to be with Rama. In the end , Rama won the battle and rescued Sita.
Rama and Sita were noble rulers of their land and ruled wisely.
We celebrate Dasahara on the day of Rama's victory over Ravana and Diwali on the day Rama returned back to Ayodhyaya.
Tuesday, July 14, 2009
Marvels of Medicine
All of us fall sick sometimes. Medicines cure us and get us back on our feet quickly. But there are many different systems of medicines prevelant in the world today:
Allopathy : also known as the Modern medicine.
Ayurveda : The classic Indian approach to the art of healing.
Homeopathy : propagated by a German Dr. Samuel Hahnemann
Modern Medicine:
Hippocrates is known as the father of medicine. He was the first to suggest that diseases are not divine interventions but natural problems, curable by nature itself.
Steps of a treatment:
When we fall sick, a doctor can cure us. First he needs to ascertain the disease. This is called Diagnosis. He may take help of some tests to accurately diagnose the disease.
Then he will prescribe some medicines in a Prescription.
We must always follow the doctors’ advice.
At times, doctors need to operate on a patient. This is called Surgery
What makes us sick?.
Diseases can be caused due to many reasons. Microorganisms like bacteria and Virus are the main culprits. Some diseases like malaria spread through mosquitoes. Some, like Typhoid are spread by eating dirty food and water. Infectious diseases are diseases that spread from one person to another.
The best way to stay healthy is to eat a balanced diet, personal hygiene and regular exercise. Remember, Prevention is better than cure.
Important types of medicines.
Vaccine: is given to improve the body’s immunity to a particular disease.
Antiseptic: is a substance that is applied to a living tissue or skin to reduce the possibility of infection.
Antibiotic: are substances that kill or inhibit the growth of bacteria. Antibiotics are given to a patient if he has bacterial infection. One must always complete the full course of an antibiotic medicine.
First Aid:
The immediate care given to someone in emergency is called First Aid.
Always keep a first aid box ready in home. A typical First Aid box will contain
1. Bandaid 2. AntiSeptic 3. Cotton wool and bandage 4.Ointment 5. Scissors 6. Common medicines.
Ayurveda, which means "science of life" in Sanskrit, is based on the premise that everything in the universe, including the human body, is comprised of five basic elements: earth, wind, fire, water and space
Ayurveda prescribes natural remedies to cure the diseases. Yoga plays a big part in ancient Indian system of healthcare.
Charaka was a prominent Rishi and the first important physician of India. His book, Charak Samhita, is an important source of Ayurvedic remedies.
Sushruta was an important surgeon of ancient India and his book Sushruta Samhita is an important document on early surgery .
Homeopathy: Homeopathy is a form of alternative medicine , first expounded by german Dr. Samuel Hahnemann. He put forth the idea of “like destroys like” , and created this branch of medicine. Homeopathy is characterised by highly diluted doses of medicine given typically in sugar balls.
Other alternate forms as acupuncture, Siddha medicine etc. also exist throughout the world.
Allopathy : also known as the Modern medicine.
Ayurveda : The classic Indian approach to the art of healing.
Homeopathy : propagated by a German Dr. Samuel Hahnemann
Modern Medicine:
Hippocrates is known as the father of medicine. He was the first to suggest that diseases are not divine interventions but natural problems, curable by nature itself.
Steps of a treatment:
When we fall sick, a doctor can cure us. First he needs to ascertain the disease. This is called Diagnosis. He may take help of some tests to accurately diagnose the disease.
Then he will prescribe some medicines in a Prescription.
We must always follow the doctors’ advice.
At times, doctors need to operate on a patient. This is called Surgery
What makes us sick?.
Diseases can be caused due to many reasons. Microorganisms like bacteria and Virus are the main culprits. Some diseases like malaria spread through mosquitoes. Some, like Typhoid are spread by eating dirty food and water. Infectious diseases are diseases that spread from one person to another.
The best way to stay healthy is to eat a balanced diet, personal hygiene and regular exercise. Remember, Prevention is better than cure.
Important types of medicines.
Vaccine: is given to improve the body’s immunity to a particular disease.
Antiseptic: is a substance that is applied to a living tissue or skin to reduce the possibility of infection.
Antibiotic: are substances that kill or inhibit the growth of bacteria. Antibiotics are given to a patient if he has bacterial infection. One must always complete the full course of an antibiotic medicine.
First Aid:
The immediate care given to someone in emergency is called First Aid.
Always keep a first aid box ready in home. A typical First Aid box will contain
1. Bandaid 2. AntiSeptic 3. Cotton wool and bandage 4.Ointment 5. Scissors 6. Common medicines.
Ayurveda, which means "science of life" in Sanskrit, is based on the premise that everything in the universe, including the human body, is comprised of five basic elements: earth, wind, fire, water and space
Ayurveda prescribes natural remedies to cure the diseases. Yoga plays a big part in ancient Indian system of healthcare.
Charaka was a prominent Rishi and the first important physician of India. His book, Charak Samhita, is an important source of Ayurvedic remedies.
Sushruta was an important surgeon of ancient India and his book Sushruta Samhita is an important document on early surgery .
Homeopathy: Homeopathy is a form of alternative medicine , first expounded by german Dr. Samuel Hahnemann. He put forth the idea of “like destroys like” , and created this branch of medicine. Homeopathy is characterised by highly diluted doses of medicine given typically in sugar balls.
Other alternate forms as acupuncture, Siddha medicine etc. also exist throughout the world.
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