By now you should be aware that in the bowels of the Earth all is not still. On the contrary, it is very active. One obvious example the the Earth’s internal working is the activity of volcanoes. There are many famous instances of a volcano erupting and spewing white hot, molten rock from it mouth; if you have been to …
Read More »Why does a magnet attract iron?
Magnets attract iron due to the influence of their magnetic field upon the iron. Before a piece of iron enters the magnetic field of a magnet, the polarization of the iron’s atoms is random. When exposed to the magnetic field, the atoms begin to align their electrons with the flow of the magnetic field, which makes the iron magnetized as …
Read More »Why does a hair-cut not hurt?
All our senses are controlled by our nerves, which carry their messages to the brain. Therefore, any part of us that has nerves also has a sense of feeling. We might fall and cut ourselves, or have a tooth that aches. We are made well aware of pain because the damaged parts contain nerves. Our hair, however, does not contain …
Read More »Why does a falling object have no weight?
Every body on this earth is attracted by the gravitational pull of the earth. A freely falling object has weight W=mg, where W-weight, m-mass of the object and g-acceleration produced due to the earth’s gravity. An object kept in a lift which falls freely, weighs zero on the weighing machine, but its actual weight is still mg. This happens because …
Read More »Why does a bull react violently to the colour red?
It is the movement of the cloth that makes the bull react violently as like most mammals, the bull too is colour blind and cannot be affected by the colour of the cloth. When a matador moves a cloth (irrespective of the colour) in front of the bull, it perceives the movement as a threat and is angered, and as …
Read More »Why do we use fingertips to touch and feel things?
There are many special nerve endings in our fingertips that let us touch and feel things-even very small things. As good as our fingertips are at feeling things, they are not the best touchers and feelers in our body. Can you guess what part of your body is the best “toucher” and “feeler”? It’s the tip of your tongue!
Read More »Why do we turn white when frightened?
We turn white when we are frightened because the blood in our cheeks in diverted to do a more urgent job. At the same time our hearts begin to beat much faster, and we breathe more quickly. When we sit still, our hearts beat at about 70 or 80 times a minute, pumping the blood through our bodies. The blood …
Read More »Why do we sleep?
Some scientist consider that sleep is an instinct, a basic need for the body and mind to relax and to escape from the responses needed while awake. We become tired in body and mind if we do not sleep, and scientists have proved that when we do sleep the electrical activity of the brain slows down, although it may be …
Read More »Why do we See a Face on the Moon?
When people say that they see a man’s face on the Moon, they are actually seeing the uneven surface on the Moon. There are deep holes, called craters, and hills on the Moon’s surface. There is no man on the Moon. That the Moon is much smaller than the stars and even the earth. In fact, four moons put together …
Read More »Why do we need water?
Very simply because our bodies are about two thirds water. The human body contains about eleven gallons of water, and as we get rid of our body water by sweating and other means, we must replace it. The water in our bodies is not the same as ordinary drinking water, of course. There are many chemicals in it, which the …
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