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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....
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)....
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....
Why are Zebras Striped?
As a child I was always full of questions. I remember asking my parents why zebras were striped or why did giraffes have such a long neck. Most of the time the answers were elusive and I used to be very irritated. I could never get the right answer to satisfy my curiosity. I now realize why my parents could not give me a concrete answer. You see I happened to be in the same dilemma when my three-year-old daughter asked me the same question!...
Why do Humans Sweat?
It is an annual ritual in most Indian homes. With the onset of summer it is time to bring the rusty, rickety old coolers down from the terrace and get them repaired. The reason is obvious – it is difficult to live through the hot, sweaty Indian summer without an air cooler. But did you know that the human body has its own cooler as well? Think of the times you have travelled in a car....
Why does Milk spill over when it Boils?
How many times have you seen milk boil and spill over, and wondered why this happens? To answer this question we have to know a little more about the composition of milk. Milk and its composition Unlike water, milk is not a simple liquid. It is a colloid and contains many substances in suspended form. These substances are mainly protein, sugar and fat. When milk is heated slowly, the proteins and fat get separated. Since they are lighter than the milk they collect on the surface in the form of a layer called cream....
Why do We Cup Our Hands When We Shout?
“Go on Sanjay, go on,” we shouted. It was the annual sports meet in our school and the 100 metres sprint was on. The White House runner Deepak was giving our Blue House sprinter, Sanjay, tough competition. As the sprinters neared the finishing line, and the shouts turned into screams, I noticed something remarkable. Everyone had cupped their hands around their mouths while shouting. The gesture caught my attention. I had seen that kind of a hand movement in plays and folk dances....