210 items in this section. Displaying page 4 of 21
What is Pluto – a Star or a Comet?
Which is the planet farthest from the sun? Pluto, of course. But, some recent findings suggest that Pluto is not a planet at all. It seems Pluto could actually be a comet, reports the National Geographic website – www.nationalgeographic.com Basically, it is Pluto’s small size that has got it into trouble. It has a diameter of approximately 1,420 miles or 2,280 kilometers. This makes it six times smaller than Earth. This fact irked scientists who always suspected that something so small could never belong to the hallowed club of planets....
Which Galaxy is Visible to the Eye?
The sun we see everyday is just one of the thousands of stars we see at night. Such a huge collection of stars is called a galaxy. And the stars we see belong to a galaxy called the Milky Way. There are millions of galaxies in the sky, most of whom are hidden from our view. However, there are some galaxies which can be seen with the naked eye. The most famous and the brightest of these is the M31 or the Andromeda galaxy....
Why do Cats Always Land on Their Feet?
When someone falls from the fourth or fifth floor, and survives, we call it a miracle. When a cat falls from that height, we watch astonished as it lands on all fours, pauses, then straighten up and walks away looking just a little fazed. What would you call this, a miracle or God’s grace? Any guesses why cats survive while humans don’t? Well, it all has to do with the in-built ability of a cat to adjust its position during a sudden fall, its light weight and lithe muscular body....
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....
What is Ham Radio?
Consider this, your state has been hit by a cyclone with wind speeds measuring 300 kilometres per hour. All modern means of communication – telephone, cellphone, wireless sets – lie dead as the cyclone has destroyed all connecting stations and links. This is what happened during the Orissa cyclone. All communication links broke down as dish antennas, radio stations, telephone lines, satellite links were destroyed. There was no way people could contact the outside world. This was when a bunch of amateurs, students and radio enthusiasts got together to set up something called an amateur radio or ham radio station....
What is a Volcano?
What is nature’s most powerful, most destructive, most dangerous form? Some would say an earthquake, others a cyclone. However, these phenomenon are relatively smaller and less destructive in scale compared to the fury of a volcano. Fourteen miles southeast of Naples in Italy, lie the remains of an ancient town called Pompeii. The city flourished under the shadows of the towering Mount Vesuvius. In 79 AD, the volcano erupted, destroying the cities of Pompeii, Herculaneum, Stabiae and Torre Annunziata....
What is Cloning?
Which is the most famous sheep in the world? A sheep called Dolly. But why is Dolly famous? That is because unlike other sheep’s, Dolly was not born in the usual manner. She is actually a carbon copy of her mother, like an identical twin. This means that she is the twin sister of her mother who is older by six years and she does not have a father! What is Cloning? [Illustration by Shinod AP] Scientists at the Roslin Institute in Edinburgh, UK, made history on 27th February 1997, when they successfully cloned a sheep....
How Does Satellite TV Work?
Nine ‘o’ clock. It’s time for your favourite serial on television. Have you ever wondered how the same serial can be viewed by millions of people across the world? This is possible because of satellite television technology. It uses man-made or artificial satellites to send your favourite serial to your television set. But why do we need satellites for this purpose? How Does Satellite TV Work? The earth is round To understand this, we have to first take a look at the shape of our earth....
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?...
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....