210 items in this section. Displaying page 5 of 21
Why do Some People snore More than Others?
If you ever slept in a room with an uncle or an aunt who snores, you would know how annoying it can be. The person causing all the noise sleeps like a log, while the room partner spends the night tossing and turning; waking up bleary-eyed the next morning. Did you know that snoring is a common ailment all over the world? Believe it or not, but on an average one in every four adults snores, says the website sleepquest....
Why does Cola Fizz?
Switch on the television and you are bound to see some cola advertisements. Aamir Khan, a Bollywood hero, pops open a cola and the bubbly drink fizzes to the top. Have you ever wondered what causes the countless teeny bubbles in all these soft drinks? Soft drinks are carbonated, i.e. carbon dioxide gas is dissolved in the liquid. This gas gives the drink its sparkle and tangy taste, and prevents it from spoiling (the gas reduces bacterial growth)....
Which Mammal lays Eggs?
Mammals are creatures who give birth to their young ones as opposed to other animals who lay eggs. Birds, reptiles and insects lay eggs. But as with every other rule, this one has exceptions* too. An exceptional exception The duck-billed platypus of Australia walks out of fresh waters to build its nest on the ground. But it has retained its love of water and returns to streams and ponds to eat crayfish, snails, and shrimp. The most remarkable feature in the platypus is that although it is a mammal, it lays eggs!...
What is Water Harvesting?
Come summer and the entire nation seems to have just one word on its lips – water. Year 2000 saw one of the worst summers recorded in the history of India. The drought in the state of Gujarat and Rajasthan was the worst in decades. Fresh water, they say is a scarce resource. Is it? During the monsoons every year, we allow huge amounts of fresh water to run off our roads and pavements into the drains where it mixes with the sewage and heads straight for the rivers where we dump waste....
How do Satellites Stay Up?
Satellites orbit the earth because of the force of gravity. To understand why this happens and why the satellite does not get pulled in and fall, we have to understand what forces do. A force will change the motion of an object; it might speed it up, slow it down or change its direction. For example, if you are running and someone pushes you from behind, you speed up (the force is in the direction of your motion)....
How does a Submarine Work?
Jules Verne in his science fiction, 20,000 Leagues under the Sea, mentions a ship, Nautilus, which could dive beneath the waves and surface again when it wanted to. Even before submarines were thought about, Verne had created the blueprint of this technological marvel. Not only did he describe the machine, but he also explained, in great detail, how it worked. In fact, today’s submarines use exactly the same technology as Verne’s Nautilus did! How does a Submarine Work?...
What is Cotton Candy?
It’s sticky, it’s messy and it’s just the thing to eat at a fair. Children or adults, most people do not consider a mela or fair complete without the giant-wheel and the fluffy cotton candy wrapped around a stick. Or budhiya ke baal (old woman’s hair), as it is popularly known in parts of northern India. And do you know what it is made of? Well, next time, don’t gobble up the whole of the candy....
Why does water stay cool in earthen clay pots?
Have you ever had a drink of cool refreshing water from a ‘matka’ or earthen clay pot placed outside? Surprisingly enough, the pots are exposed to blazing sunlight, yet the water within stays so cool. How is that possible? This is because of a physical process known as evaporation. When a liquid changes to a gaseous (or vapour) state without boiling, it is known as evaporation. A matka is made of mud and has many minute pores (extremely small holes)....
Why can’t the Sun melt Snow?
There are some things in nature that have a great capacity to toss back or reflect a great deal of the sun’s light that falls on them. One of them is snow. Newly formed snow reflects about 90 per cent of the sunlight that falls upon it. This means that the sun is powerless to melt clean snow. And when snow does melt, it is not because of the sunlight. Snow does not melt on a spring day because of the sun’s heat....
Why's the Sun Red during Sunrise and Sunset?
As day breaks, a reddish-white ball of light that we call the sun, rises. This red haze gives way to a golden-white sheen as the day advances and reappears when the sun sets in the evening. Does the sun really change colours, or does it only seem so? The explanation lies in-between. Light from the sun consists of three kinds of radiation – ultra-violet rays, visible light and infra-red rays. Unlike visible light, ultra-violet rays and infra-red rays cannot be seen....