Science & Mathematics Questions & Answers

In 1934, people in the city of Boston in the north-eastern USA watched in amazement as clouds of choking yellow dust passed over them on their way to the Atlantic Ocean. The dust had come from the Great Plains in the American Midwest. These plains are generally treeless, because the average yearly rainfall is less than 500mm (20 in) and …

Most people have dark eyes, usually brown. These people usually have dark hair. People with blue eyes tend to have fair hair.

Whirlpools are a threat to small boats. The whirlpools between Sicily and mainland Italy, named Scylla and Charybdis, were once thought to be the lairs of sea monsters that swallowed ships. Whirlpools are often caused when strong currents are confined between rocks or when two currents meet.

Tidal waves, or tsunami, as scientists call them, are very often the result of earthquakes on the bottom of the ocean. The sea bed shifts and slides like an earthquake on land, causing a great shock wave. Ships that are in the area of the quake fell this shock wave as if they had just struck a rock. Sometimes the …

These are caused by calcium collecting under the nails.

We know how great sheets of ice extended over many areas of the Earth’s surface at certain times during geologic history called Ice Ages. The water which made up these icy masses came from seas so that the sea-level fell, but at the same time the weight of the ice pressed down upon the Earth and when the ice retreated …

Major floods can occur in several different ways. For example, in 1840, an earthquake caused a landslide in the Himalayas, damming the upper course of the River Indus, so that a lake soon formed. The lake was 64 km (40 miles) long and over 300 m (984 ft) deep, and when this natural dam broke, flood water swept down the …

It you walk down a street in any town or city, you will see lots of people with different coloured skin: white, black, yellow and coffee colours all appear. But why do people have different coloured skin? The reason is that in your skin you have substances which, under certain conditions and with the correct chemical processes, make colour – …

To understand this, we should first realize that our skin is in two layers. There is the outer layer and the inner one which carries nerves and blood-vessels. Beneath the skin is a loose layer of tissue which contains fibres that run in all directions. A few of these fibres are attached to the under-surface of the skin so that, …

A Wave snakes are long red tubes that help convert the motion of waves into electricity and form part of a commercial wave power station. It was developed by a British company and took 10 years to create. Currently, the pilot wave-power project has been launched off the coast of a Portuguese town called Agucadoura, and aims to power 1,000 …