210 items in this section. Displaying page 20 of 21
Why is the Mediterranean Sea Blue?
We know that about seventy one per cent of the earth’s surface is covered with water. The earth’s three main Oceans are the Atlantic, the Pacific and the Indian Ocean. The Atlantic Ocean is a great mass of water that separates Europe and Africa from America. It is shaped like a great hour-glass-with a ‘waist’ where Africa and South America bulge out towards each other. Although in area it is less than half the Pacific, it has many ‘secondary’ seas, such as the Arctic Ocean and the Mediterranean Sea....
What are Truffles?
Every year, between November and March, people in southern France and Italy are busy trampling the woods, sniffing the air and peering under the roots of elm and oak trees looking for truffles. Truffles? Hey, its no trifling matter – there are organisations in France and Italy which let you take part in truffle hunts! Truffles are a rare and delicate type of edible mushrooms that look like little potato nuggets. They grow in open woodlands in regions with a warm and moderate climate, on soil rich in calcium or limestone....
When will the Oceans of the Earth Overflow?
Try this out. Plug the sink and leave the water running. It will lead to a flood in the bathroom and a scolding for letting the water overflow. Since the sink could not hold an unlimited amount of water, it let the water spill out. But even the oceans are enormous bodies of water that get flooded with water from rain, melting ice, and rivers year after year. Will they start overflowing too? If so, when?...
What are Canal Locks?
In some rivers or canals the water is not too deep for large ocean-going ships. In such places large watertight compartments are built that help ships and boats go up or down different levels on rivers or canals. These are called canal locks. In certain areas, man-made canals are constructed to connect two water bodies. These canals are built to help cut down the distance a large ship would otherwise have to take to reach its destination....
What kind of Family Life did the Dinosaurs Have?
In Argentina this year, scientists digging on a site made a fantastic discovery, which made them realise that dinosaurs lived as a large family. The site consisted of many nests with each nest containing as many as 15 to 30 eggs. The eggs belonged to a plant-eating dinosaur called Titanosaurs. It is the biggest nesting site of dinosaurs found so far. The word dinosaur is a Greek word meaning giant reptile. Most reptiles lay eggs in nests but they walk away after the young hatch to fend for themselves....
Why are Some Reptiles Brightly Coloured?
Most animals have skin colour that makes them merge into their surroundings. They become near invisible unless you look very closely. But some reptiles such as the sea-snakes, coral snakes and frogs of Central and South America are brilliantly coloured or have bright bands like deep yellow, orange, pink on their bodies. They are easily visible among the green leaves or brown earth. This is because these animals are poisonous. The colouring is a warning to other animals, especially their natural enemies, to avoid eating them....
Why do Earthquakes Occur?
As a result of upheavals below its surface, the earth shakes now and then. This shaking of the earth is known as an earthquake. Few natural events are as violently destructive as an earthquake. It usually strikes without warning, giving off violent vibrations in the process. These vibrations not only shake the ground but also sometimes crack it open. And then, there is chaos, for earthquakes have been known to wipe out cities and civilisations....
Why do Beavers Build Dams?
Picture a giant rat with a flat tail and webbed feet. That’s what the beaver looks like. There are two kinds of beavers: the American and the European. The European beaver, found in Norway, Poland, Germany and France, lives in burrows. But the American beaver builds a dam across a stream or lake to construct his home or lodge. The lodges are made of huge logs of trees. Why do Beavers Build Dams? [Illustration by Sudheer Nath] The American beaver constructs solid dams and lodges because it has the mind of an expert engineer among all the creatures in the animal kingdom....
What does SOS mean?
Recently, sailors on the nuclear submarine that sank in the Baltic Sea were isolated from rescue workers as their radio set got damaged. Luckily their radio operators knew the Morse code and were able to communicate by knocking on the sides of the ship. There are many explanations for what the words stand for: Save Our Souls; Save Our Ship; Send Our Succour… The meaning of all three is the same – it is a plea for help by someone in distress....
Why are Eggs Oval?
Have you ever climbed a tree and peeked into the nest of a crow or a sparrow? Or looked into that flowerpot where the noisy pigeon decided to lay its eggs? The sight of a mother hen sitting on a bunch of fresh white eggs is great, though most of us see them only when they land on the breakfast table every now and then. Eggs come in different colours. They may be blue, blue-green, yellow, spotted, blotched or white....