Science & Mathematics Questions & Answers

Science & Mathematics Questions & Answers

Do blood groups vary according to race?

Experts studying different human populations are very interested in the distribution of blood groups. For example, it has been noted that Amerindians (American Indians) are practically always blood group O. There are very few pure Amerindians with blood group A, and group B is conspicuous by its absence. Asiatics have far more member of group B than Europeans Among Europeans, …

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Did you know that the first submarine was powered by just one man?

The first submarine to go into action was an American vessel called the Turtle. It tried to attack a British warship in 1776, during the American War of Independence. The Turtle was an egg-shaped craft powered by one man, who sat inside and turned two handles connected to screw propellers outside. Manned by Sergeant Ezra Lee, the Turtle’s mission was …

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Did the Romans use flags?

The answer, in the modern use of the world flag, is ‘no’. The world is of Germanic origin and was used in the fifteenth and sixteenth centuries to mean a piece of cloth, or other material, displaying the insignia of a community or armed force, an office, or an individual. They were used originally mainly in warfare, and were signs …

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Cutting without knives and welding without torches-how’s it done?

Surgeons can cut tissues without using knives. They use a laser beam which delivers intense heat to the tissue. The beam cuts effortlessly and with total cleanliness. It also seals blood vessels so that the cut does not bleed. Eye surgery can also be carried out by laser-without cutting open the eye! The retina at the back of the eye …

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Could robots ever perform surgical operations?

It is possible that robots may begin to perform some surgical operations on people. The robot would be directed with great precision by a computer working from pictures of the inside of the patient’s body taken with scanners. The computer would be controlled by human surgeons, who would check the progress of the operation on video screens. Robot surgery could …

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Can you spot the dragon, the unicorn and the giraffe in the sky?

These animals are all represented by star patterns known as constellations. A total of 88 constellations fills the entire sky, and some of them have very odd names. The most famous constellations date back to the ancient Greeks and Romans, but imaginative astronomers have introduced additional ones since then. Among the constellations is a dragon, called Draco, coiled around the …

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Can you ever hurt a robot?

We think of robots as perfect machines that never do anything wrong, let alone get hurt. However, there are some robots whose whole purpose is to get hurt and to say ‘ouch’. These robots are dummy patients for dentists. They have a model human head, and student dentists practise doing fillings and other kinds of dental work on the robot’s …

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Can there be light without heat?

Yes, we can have light without heat. The light from such reactions is called cool light. Many chemical reactions produce both light and heat. A burning candle is such a reaction. It is much less common for a chemical reaction to produce light without heat. Such chemical reactions are called chemiluminescent reactions, the most familiar of which occur in living …

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