54 items in this section. Displaying page 4 of 6
Why is the Ball-point Pen Called So?
Writing is one of the most important inventions. Humans first used brushes for writing, then thick reeds were used. Feathers were used in medieval Europe for writing. In the mid-19 century, metallic pens and nibs were widely used, while the fountain pen was produced in 1884 by the American, LE Waterman. However, these pens had a lot of problems. The ink would spill and blot very frequently and writing was cumbersome. The first ball-point pen was invented by an Hungarian journalist, Ladislo Biro, in 1938....
Everything is made of something
How do you make tea? Simple, put a teaspoon of tea into a boiling cup of water. Strain the water, pour some milk and sugar to taste and the tea is ready! Interestingly, everything that we prepare has a recipe and is made up of simpler ingredients. For example, what is sugar made of? It is made of sugar molecules, which in turn, are made up of atoms. The atom is the building block of all substances....
What were the Voyager Missions?
Imagine a journey that takes you a billion kilometres away from earth, to the edge of the solar system, from where you can look back over your shoulder and see our sun as just another star in the sky. We are not talking about a science fiction movie but the Voyager space mission. On August 20, 1977, the Voyager 2 spacecraft was launched. Close on its heels, the Voyager 1 was launched on September 5, 1977....
How Will our Sun Die?
Everything that is born must die. Not only living beings, but inanimate objects like stars too. The birth of a star The universe has massive clouds of hydrogen floating around. Sometimes, these clouds come together and form very dense and huge balls of hydrogen gas. As the clouds come close, their temperature increases. This is called a proto-star (original star). The increase in temperature triggers off nuclear reactions at the core of the star. Nuclear reactions inside the star occur when the nucleus of two hydrogen atoms fuse to produce a helium atom....
All Human History is Just 10 Seconds Old!
Look at the dial of a clock. Imagine that the 12 hours showing on the dial are equal to earth’s history of four-and-a-half billion years. Now, this is how the earth’s evolution happened… We know very little about what happened in the first three hours of the earth’s existence. The first signs of life appeared in the form of bacteria when the earth was four hours old. Then came the first vertebrates (animals with skeletons). They were born when the earth was 10 hours and 35 minutes old....
Why does a Cricket Ball Swing?
How many times have all of us heard that the former captain of the Indian cricket team, Kapil Dev, was one of the greatest out-swing bowlers of all times. Indeed! He took more than 430 wickets in Test cricket. But, do you know how a cricket ball swings? The term ‘swing’ refers to the movement of the cricket ball in the air after it leaves the bowler’s hand, which takes the ball away from or towards the batsman....
What is a Kangaroo Rat?
It looks like a small kangaroo for its hind legs are longer than its fore legs. And it uses its tail to balance itself. In fact, unlike other rats it does not run on all four legs but jumps around from bush to bush in search of food – like a kangaroo. And that’s why it is called the kangaroo rat. It has another unique feature. Unlike most animals, the kangaroo rat does not need to drink water....
Little Blue Daisies
Little Blue Daisies [Illustration by Shinod AP] Little blue daisies in my flowerbed First came the ladybird red red red Fly away ladybird said the daisy blue Poor little ladybird flew flew flew Then came the grasshopper green green green He hid in the leaves not to be seen Hop away grasshopper, said the daisy blue Poor little grasshopper Went hop, hop hop Third came the bumblebee black black black...
What is Geothermal Energy?
In winter, all of us warm water in the geysers in the bathroom for bathing. Nature too has geysers which throw up a huge amount of hot water and steam. The ‘Old Faithful’, as one of the geysers in the Yellow Stone National Park in the United States of America is called, spews out boiling water at intervals of 33 to 120 minutes. Old Faithful, as one of the geysers in the Yellow Stone National Park in the USA is called, spews out boiling water at intervals of 33 to 120 minutes Why do natural geysers spew hot water?...
How can We Use Water to run Cars?
Huge amounts of polluting gases are being released into the earth’s atmosphere by the large scale burning of fossil fuels or natural fuels found under the earth. These gases are the main culprits behind the phenomenon of global warming and other climatic changes. In order to find cleaner fuels, scientists around the world are trying to find a fuel or source of energy which produces little or no pollution on being burnt. Quite amazingly, a new technology points out that water can be used to generate electricity....