Science & Mathematics Questions & Answers

Nowhere-it simply changes into other substances. That is what burning does to everything. The moment you put a match to the wick, you start a change in the candle by turning the solid wax into a liquid. The liquid wax rises to the wick by an irresistible process called capillarity, the simplex example of which is the way blotting paper …

Cowrie shells are widely distributed and possibly the favourites among shell collectors because of their polished enamel-like surfaces and their beautiful colored patterns. The cowrie appears in all the warmer seas of the globe. But the great cowries, the tiger cowrie and the orange cowrie are natives of tropical regions. They crawl slowly, browsing on weeds, and are shy creatures …

If you have a pair of jeans, you will know that what they are made of is a cloth called denim; but do you know where the word comes from? At first, it was used to describe a serge cloth made in Nimes, France – the original name was ‘serge de Nimes’. Gradually, these last two names were shortened and …

We know that the Earth’s crust and the top part of the mantle are split into rigid sections, called plates, which are up to 70-100 km (43-62 miles) thick. Beneath the plates, temperatures are high and the rocks are semi-molten. Currents in the molten material are moving the plates about. Plates are moving apart along the ocean ridges. When they …

Spacecraft cannot carry large supplies of fuel and these aren’t any filling station in space. Instead, many have large panels of solar cells. These capture sunlight and turn it into electricity. The sun always shines in space, so there is always electricity to power the spacecraft. Some space probes travel to the outer planets far from the Sun. There the …

The first sound you hear, the one which says ‘lub’ is caused by the rapid closure of the valve between the auricles and the ventricles (auriculo-ventricular valves). This sound, rather like a door closing, is accompanied by a dull murmur, caused by the contraction of the ventricular muscles. The second sound is caused by the closing of the arterial valves. …

The simple answer is either they are stored in your memory or you forget them. But this question makes us ask a great number of other question. What is the difference between day-dreaming and the dreams we have when we are asleep? Can dreams foretell the future? How long do they really last? Do we have dreams in color or …

Every night the chimpanzee spends five minutes making its bed for the night. It bends two or three leafy branches together to make a platform quite high up in the trees. It curls up on its side with legs drawn up and soon falls asleep.

Butterflies, and moths as well for that matter, are very particular about laying their eggs. Most butterflies leave them on only one sort of plant because this is the plant that the newly hatched larvae, called caterpillars, will feed on. So the female butterfly will spend some time finding the correct plant (the foodplant) before laying her eggs. You might …

The sponge with which some people regularly soap themselves in the bath is really the skeleton of a particular type of natural sponge. Bath sponges are supported by a framework of a resilient, elastic material called ‘spongin’, and it is this that makes up the bathroom sponge. Bath sponges are found in warm shallow seas, and in various part of …