As a result of Tasman’s discoveries, Australia, Tasmania and New Zealand were thought to be part of one enormous continental island. It was shown on maps of the time as Terra Australis Cognita (or Southern Known Land) separated from another to the south shown as Terra Australis Incognita (or Unknown). Captain Cook, however, proved that the former was not one …

Suppose that today is February 13, 2053. The day of the week is a Thursday. One week (seven days) from today, on February 20, 2053, it will be Thursday again. After two weeks (fourteen days), it will be Thursday once more. We need to figure out how many weeks and days will have passed after a year. 2053 is not …

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.

तालाब किनारे राेती थी, कल बिटिया इक बैरागन की, जब जालम कागा ले भागा, बिन पूछे टिकिया साबुन की। ये बाल भी लतपत साबुन में, पाेशाक भीतन पर नाजक सी, था अब्र में सूरज भी पिनहां, आैर तेज हवा थी फागुन की। आंचल भी उसका उड़ता था, आैर हवा के संग लहराता था, इक हाथ में दामन थामा था, इक …

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 …