Sarbadhikari
	KNOW-HOW
	Curiosity never killed the cat

HOW DID @ COME TO BE USED IN E-MAIL ADDRESSES?
Since medieval times businessmen have used the @ symbol as an abbreviation for 'at' e.g. lemons @ 10 pence each. This is why it was included on typewriters and subsequently on computer keyboards. In 1972 American software engineer Ray Tomlinson devised the first e-mail programme. He needed a symbol to separate the user name from the machine details. This character had to be one that would never be found in someone's name - and so he chose the @ sign.

WHAT WILL THE PRESENT DECADE BE CALLED?
Having left the Nineties, which decade are we living in?
It's up to the public to decide. There is no official body to make a declaration. Some of the suggestions made are, 'the Noughties', 'the Oh-Ohs', t'he MMs', 'the Zeros' and the 
'20 Hundreds'.

WHY IS THE MOUTH COLD AFTER EATING MINTS?
The taste-buds in our mouth are sensitive to various temperatures as well as taste. Menthol, the essential oil in mint, deadens the hot receptors in the mouth over the cold receptors. The signals from the hot receptors to the brain are reduced and those from the cold receptors stand out. The brain interprets these signals as a cold sensation.
The opposite effect is obtained by red chilli which imparts a feeling of extreme heat by blocking out the cold receptors.                                         (From The Telegraph, Calcutta, 25-Sep-00)

WHY DOES FOAM OCCURS IN SEAS & RIVERS?
The salts and minerals that are found in the sea and river water are responsible for the formation of foam. Sea water is known to contain a high proportion of salt such as sodium chloride and minerals like magnesium and its compounds. During the day the water gets heated up. This increase in the temperature of sea water facilitates the reaction between salts and magnesium compounds and leads to the formation of compounds such as magnesium chloride.
This chemical reaction produces a large amount of heat. The resultant gaseous vapour is insoluble in water and forms a white foamy substance, which floats on the water surface.
        In rivers foam occurs somewhat differently. It is caused by an aquatic bacterium, Rhodopterus sellagi. These bacteria, found in abundance in rivers, have special types of cells, which secrete a magnesium containing pigment called sellagin. Sellagin is whitish in color and in contact with water forms foam. 
                                              - Malabika Mazumdar (Know-How, The Telegraph, Calcutta)

WHY DOES GLASS BREAK SO EASILY?
Theoretically the strength of glass is very high. This is drastically reduced in practice due to the presence of impurities like dust, metal particles and surface irregularities produced during manufacturing.
    At ordinary temperature, the internal state of glass with its random molecular orientation resembles a fluid. Externally glass displays the rigidity and hardness of a solid. Hence glass is often described as a super-cooled fluid.