In fact, shooting stars are not stars at all. We call them meteors, and scientists believe that they are broken fragments of comets, which still move about in space when the comet itself does so no longer. We see them when they enter out atmosphere because they leave a trail of light behind them, caused by the friction of air …

Seed crystals are tiny single crystals made to dissolve in a solution (or melt) from which larger crystals are drawn either by precipitation, centrifuging or drawing up from a melt. Seeds have the same chemical composition and crystalline structure as that of the larger crystal. Large crystals are grown on a preferred geometer (normally the most densely packed) plane of …

It is an emergency shutdown of a nuclear reactor by inserting a large number of negative reactions into the system. It is derived from the WWII usage of the term ‘Safety control rod axe man’ which referred to emergency situations wherein a rope was cut to stop the operations urgently and to limit the damages arising out of continuance of …

A scale model is a representation or copy of an object that is larger or smaller in size. Its size is proportionate to the original size of the object that it represents. The proportion is often shown in some ratio eg 1:10, which means one inch of scale model is equivalent to 10 inches of original object. Very often, the …

When winds blow from the sea up high coastal mountain ranges, they shed much of their moisture as rain or snow. However, when they blow down the leeward (sheltered) slopes of the range, they get warmer and pick up moisture, so the leeward side of the range is dry. It is said to be in a rain shadow area.

Ordinary railway lines usually look as though they are laid on level ground. In reality most stretches of railway track have a slight gradient, so that during a journey of any reasonable length, a train will be running up and down a number of very gradual slopes. However, there is definite limit to the degree of steepness a train can …

The world race is often wrongly used. For example, the Jews are not a race, but a religious and cultural group, who, in racial terms, are exactly the same as the Nazis who persecuted them. Many scholars say that there is only one race-the human race. However, the human family can be divided into several groups according to such features …

Quadrillion is 1,000 trillion. It has a value in which 1 is followed by 15 zeros in Short Scale countries such as UK and USA. In Long Scale countries like some European nations, quadrillion is 1 followed by 24 zeros.

A supernova leaves behind a tiny object termed a neutron star, far smaller than the Earth. It is the core of the star that exploded. The protons and electrons of its atoms have been squashed together by the force of the supernova, to from the atomic particles known as neutrons. A neutron star is unimaginably dense. It contains the mass …

A prime number is one that cannot be split up by division. Think of 11. Twice six is 12, three fours are 12. But the only number you can divide 11 by is one, and when you have done that you still have 11 left. Prime numbers lie at the very roots of arithmetic, and have always fascinated those concerned …