Percival Lowell, an American astronomer, thought he saw canals criss-crossing the deserts of Mars, when he observed the planet though his telescope early this century. He believed that these canals were built by a Martian civilization to bring water for irrigation from the planet’s polar caps. However, space probes have shown that the canals were simply optical illusions, and that …
Read More »Are bats really blind?
Bats are not blind. Like many animals, they are born blind, but gain eyesight from the time they are seven to nine days old. Bats are night creatures. They come out only at night to hunt. Although they can see reasonably well they have no special eyesight possessed by other night creatures like the cats and owls. Instead, bats fly …
Read More »Are all snakes dangerous?
It depends what you mean by dangerous! Certainly, not all snakes are poisonous, and of those which are, only a very small number are dangerous to people. But in the same way that people could be said to be a danger to the things they eat, snakes are dangerous to their prey. Most snakes kill their prey- rats, mice and …
Read More »Are all deserts hot?
The definition of a deserts is a place where the lack of moisture makes it impossible for anything but a few special life forms to grow. This applies not only to hot places, like the Sahara and the Gobi deserts, but also to very cold places too. Because all or most of the moisture there is turned to ice, almost …
Read More »Anyone for the shuttle?
When the first manned satellites went into space in the early 1960s, many people felt that the wildest dreams of science fiction writers were coming true. It was only about 50 years earlier that the first aeroplanes had flown. What amazing progress had been made in half a century! But in the next 20 years events moved still faster In …
Read More »Amazing facts about animals
Amazing facts about animals — A captive, great brown bear of Alaska, a close relative of the fabled grizzly bear, weigh about 650 kilograms! The female Emperor penguin comes to the land, lays one egg on bare ice, then immediately returns to the ocean. The male keeps the egg warm for two months until it hatches, by rolling it onto …
Read More »Accidental discovery
During World War I a metallurgist called Harry Brearley tried mixing chromium with steel to make a stranger gun barrel. It didn’t work. The barrel shattered. But the metal pieces he threw away outside stayed bright and didn’t rust. Quite by accident, the secret of making stainless steel had been discovered.
Read More »Why is the Adam’s apple called so?
Another name for the larynx is the voice box, and it’s in the throat. The larynx is what gives you your voice, whether you’re talking, laughing, whispering, singing, or screaming! You can find your larynx by touching the front of your throat and humming. When the larynx grows larger during puberty, it sticks out at the front of the throat. …
Read More »Why do you have hair?
All mammals have some hair, and man is also mammal. In some mammals, hair covers the whole body, but in man, it grows only in certain parts. Your hair has two main purposes: to provide warmth, and to protect your skin and body openings. While the hair on adult’s body is not as thick as on an animal’s body, it …
Read More »Why do you catch a cold?
The most contagious disease in the world is the common cold. Colds are actually infections of the mucous membranes of your nose and throat, but sometimes they spread to your air passages and lungs. The germs or viruses, that cause these infections and make you cough or sneeze, travel through the outside air inside tiny droplets of moisture. Doctors believe …
Read More »