What is perpetual motion? Scientists once believed that they could create a perpetual motion machine which could continue working even if energy is not supplied to it. But this is not possible. Even in the most efficient machine, energy is lost as heat. This ensures...
Why is the number 13 believed to be unlucky? It is just another superstition but some people take it seriously. Many hotels don’t have a 13th floor and most people take care not to have 13 persons at a dinner table. Perhaps it has something...
What was a vomitorium? The Romans loved feasts. Some of their dishes included oysters, stuffed dormice, roast peacock and boiled ostrich. Some of the rich Romans were gluttons who believed in stuffing themselves as much as they could. In order to eat more they forced...
When did dentistry begin? Dentistry was practised in ancient times. In Greece around 2,500 years ago, there were tooth extractions by dentists but they were mostly loose teeth. It was in the Middle Ages that cavities began to be filled. Fillings were made of wax...
When did puppet shows originate? Puppet theatres existed in India and Egypt thousands of years ago. The first puppets were probably made in these countries. Marionettes are puppets manipulated using strings and they were popular in Italy. Java, Thailand and Greece had shadow plays made...
What is rabies? Rabies is a disease that is caused by a virus which can infect all warm-blooded animals. Usually it is transmitted from dogs to man. The disease affects the spinal cord and brain. It is also called hydrophobia because the victim seems to...
Why do giraffes have very long necks? The giraffe’s long neck is probably the result of many years of adapting to its environment. The giraffe feeds on the leaves and twigs of tall trees like the acacia. Its long neck helps it to feed easily....
Do buildings have skeletons? In the 1880s, architects began using skeletons of steel and concrete columns to support the roof, walls and floors of tall buildings. Outer walls were fixed to this framework. This helped to construct tall skyscrapers which adorn the skyline of many...
What was the first advertisement? The oldest advertisement or publicity that is known to man is an ancient Egyptian papyrus. It is almost 5,000 years old. The message is in the form of hieroglyphs or picture writing. It advertises a reward for finding a slave...
How big were the babies of dinosaurs? A Dinosaur babies are very small when they are newly hatched. A baby Protoceratops could easily be held in one’s hand. The fossil of a baby Troodon which was found was only 7 cm long. Which means that...
