How does the weather affect the shapes of our houses?   As you may know, the weather is not the same all over the world. If you live in Britain and visit say, Spain, for your holidays you will know that Spain is generally warmer and drier than Britain. Some parts of the world are so hot and have so little rain that they are called deserts where there may only...

How did man reach the moon?   In 1969 an American, Neil Armstrong, became the first man to set foot on the moon. Getting him there had taken years of work by thousands of people and many millions of dollars. The way the flight was made is shown in the picture. The launching rocket had three ‘stages’. When each stage had used up its fuel it dropped away to lighten the...

How does a rocket defy the force of gravity?   If you jump up as hard as you can you still fall down again very quickly. This is because of the pull of the earth’s gravity. If we want to `jump’ into space we need to push away from the earth so hard that gravity cannot pull us back. To do this we use rockets. A rocket works by shooting hot...

When was the first aeroplane flown? Wilbur and Orville Wright of the USA made the first successful powered flight in 1903. They flew a two-winged ‘biplane with a petrol engine weighing 90 kg (200 lb) that they had built themselves. The first flight lasted twelve seconds and covered 36.5 m (12o ft). Aeroplanes developed quickly. In 1909 Louis Bleriot of France flew across the English Channel. The next year an American,...

How can heavier than air machines fly? For an aeroplane to fly two things were needed: specially shaped wings to give ‘lift’ when they rushed forwards through the air ; and a good enough propeller-engine to drive the plane forward. The wing shape is called an ‘aerofoil’. It is curved so that the air rushes over the top very quickly. This causes the wing to lift. The first heavy machine to...

Must man grow wings in order to fly? There were two ways man might be able to fly. One was to copy the way birds fly. That is he could use a machine which was heavier than air with some kind of wings. However, the heaviest bird is only about 16 kg (35 lb and we weigh much more. The other way was to make a machine lighter than air so...

Birds can fly – why can’t we? Some of man’s oldest legends are about his dream of flying. A Greek myth tells of Daedalus and his son Icarus. They escaped from the island of Crete using wings of wax and feathers. Icarus was supposed to have flown too near the sun. It melted his wings and he fell into the sea and drowned. Many people, seeing birds fly, thought feathers were...

Mongol Empire At its height, the Mongol Empire covered almost the whole of Asia. It ran from the coast of China to the borders of Europe, extend north into Russia and south into Persia. No other empire in history has controlled such huge piece of territory, which amounted to about a fifth of the land surface of the world ! yet it began in a small way and lasted a comparatively...