What makes us laugh?
We laugh when we are amused or happy. Actually, laughter is an expression of many feelings. And only human beings are capable of expressing their feelings like this.
Experts are still working on some questions about laughter, such as, what makes people laugh, and what is the function or purpose of laughter. Whatever the explanation, one thing everyone knows is that laughter is good for our health. It is good for our lungs; it is also good for our minds.
According to one theory, laughter has a great social value.
We laugh usually as members of a group. Laughter is used by social groups as a
way of commenting on the behaviour of people and making them conform to our
standards.
Watching a funny play or a humorous film with your classmates can give you more pleasure than seeing it alone in an empty room. Telling jokes and listening to them is a source of amusement to make everyone laugh and enliven the atmosphere.
What you should never forget is to see that your laughter must not hurt or insult the other person. Instead, develop a sense of humour and learn to laugh at yourself.
What are your vocal cords?
Vocal cords are the organs inside your throat area that help you speak, sing or produce any other voice. These cords are made of elastic fibres which can vibrate like the strings of musical instruments. When a column of air from inside you strikes your vocal cords, they begin to vibrate. These vibrations produce sound waves.
What we call deep tones, are produced when the vocal cords are slack and vibrate only about 70 to 90 times per second. The high-pitched sounds are produced when the cords are tense and are vibrating at a very high frequency, about a thousand times per second.
The general pitch of a voice depends on the length of the vocal cords. Children have short vocal cords, so they produce short waves and the sound produced has a high pitch.
What are your vocal cords?
It is amazing but true that no two people in the entire world can have exactly the same fingerprints. Even twin brothers or two very similar-looking persons cannot have the same fingerprints. This fact is very useful in solving mysteries detecting crimes and catching thieves.
The human skin consists of two layers of tissues. The inner layer is thick and is called ‘corium’. The outer layer is a thin membrane and is called the ‘epidermis’.
In cold-blooded animals, these two layers of the skin fit smoothly one upon the other. There are no ‘ridges’ or grooves to make patterns. But in human beings, there are ‘ridges’ that form certain patterns and these patterns are different in every different person.
Sir Edward Henry, an Englishman, first developed the system of classifying fingerprints by carefully studying different patterns made by the fingerprints of different persons. Even today, the same basic system of classifying fingerprints prints issued everywhere.
The ridges on human fingers can be divided into these basic patterns, central pocket loops, double loops, arches, tented arches, whorls and accidentals.
By counting the ridges between fixed points in the pattern, each of the ten fingers can be classified into a definite group. The chances that two people will have the same pattern on just one finger are one in twenty-four million!
Why do some people have curly hair?
Hair can have many different colours, textures and thicknesses for different people. Some people have straight and silky hair; some have coarse and thick hair. The rate at which a person’s hair grows is also different from another.
Our hair gets nourishment from its root where it is attached to our scalp. At the root of the hair, some cells contain pigment. These cells multiply and go upward with the growing shafts of hair.
The cells die, but the pigment granules remain with the hair.
The colour of the hair depends on the colour of these pigment granules. If the
pigment granules contain black color the hair will look black. If it has a reddish shade the hair will look red.
The horny substance, in which the pigment is buried, is yellow. The final colour of the hair is a mixture of these two.
If you cut across a shaft of hair and see it under the microscope, its structure will show a definite shape: round, oval, flat or elliptical. The texture and shape of hair depend largely upon this. Round-shaped hair produces straight hair, while the oval ones produce wavy and curly hair. Elliptical or kidney-shaped hair will produce short and curly (also called ‘woolly’) hair.
Why are some people left-handed?
You must have seen people who eat, write or play tennis with their left hand. But more people on the earth are right-handed. Less than one person in six is left-handed.
Our brain is a complicated organ. The right half of the brain controls the left side of the body, and the left side controls the right side of the body. In most people, the left side of the brain is better developed, so the right hand is more efficient and stronger than the left one.
No one knows for sure why it happens, but sometimes in some people the right side of the brain is better developed. And this makes their left hand work better.
According to some experts, the reason may go back to ancient days or even the days of the caveman. When people fought, a right-handed person would fight with a weapon in his right hand and use his left hand to shield his body.
The left-handed person would shield himself with the right hand while using the left hand for fighting. The person who shielded his body on the left side protected his heart because the heart lies on the left side.
So many fighters had better chances of survival. The left-handed fighters would be wounded around their heart and die. So that more right-handed persons lived on earth.
Tags
science