WHY THE LEANING TOWER OF PISA DOES NOT FALL?

LEANING TOWER -

The Leaning Tower of Pisa is one of the most amazing structures in the world. Located in the city of Pisa, Italy, it is visited by hundreds of people every day. Very few people know the reason for its leaning. Made of white marble, this structure has walls 4 meters thick at its base. It has 8 floors and is 54.5 meters high and measure 15.8 meters around the bases. There is a stairway, which leads to the top and has 300 steps. From its top, it is possible to get a breathtaking view of the city and the sea, which is 10 kilometers away.

Now the question arises - what makes this tower lean and why does it not fall?
Plumbline from the top is meters away from the base, i.e. it leans over by 4 meters. If we drop a ball from its top, it would hit the ground 4 meters away from its base.

Originally, it was intended as a bell-tower for the cathedral, which is nearby.  Its construction was started in 1174 A.D. and completed in 1350 A.D. When the construction started nobody thought that it would lean, but it started leaning as soon as the third story was completed. The foundation of the tower was laid in sand and this may explain why it leans. Since the tower started leaning, the plan for its construction was modified and then the tower was completed. Since 1918, yearly measurements have been made. These measurements show that the leaning is increasing. During the last one hundred years, the tower has leaned another 30 centimeters.

But why does it not fall even while leaning?
According to science, anything will remain stable as long as the vertical line drawn from the center of gravity passes through its base. The center of gravity is that point where the whole mass of the body is supposed to be concentrated. Till today the vertical line from the center of gravity has been falling within the base of the tower. That is why it has not fallen. It is believed that when the tower leans further and the line from its center of gravity passes out of its base, it will fall down.

However, by using different new methods and techniques, engineers and technologists are now trying to arrest further leaning of the tower.

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WHEN DID PEOPLE FIRST USE MONEY?

MONEY -

Money has always fascinated man ever since ancient times. Money has come to become the most important thing in the world. Aristotle observed that man is a social being who establishes certain norms and regulations for his social interaction. The man employed money as a mode of exchange to facilitate such social dealings for his economical aspect.

In primitive societies, when people wanted to buy anything, they had to give something else in return for it. For example, if a potter wanted to buy rice from a farmer, he offered him earthenware in exchange for rice. The farmer would accept them because he needed pots. This was called the barter system, which involved goods in exchange for goods.

During those times goods served the purpose of money. But with the development of trade, the barter system could not meet the growing demands of a convenient exchange system for buying and selling. People started using the token or symbolic goods in exchange all over the world. American Indians used beads of shells, Fijians used whale's teeth and North Americans used tobacco in their exchange system. The Roman army men were provided salt for their services. But when was the coin first used as currency?

The precise origin of money in the form of coins is not clearly known. According to the available sources, the earliest coins were minted in about 800 B.C. when Indians who lived in Asia used stamped pieces of metal as a medium of exchange. Some believe that the Chinese used coins even earlier. Coins were preferred because they were easy-to-carry and durable. The early coins were of irregular shape and were stamped with rough designs. The money value of coins depended on the value of the metal that the coins were made of. Coins were mostly made of gold, silver or copper because they were precious and durable metals.

The use of paper currency was known to China as early as in the 9th century but it did not develop in Europe until the 17th century. The governments of different countries favored the use of paper currencies and coins to simplify the monetary dealings. It helped because what mattered was the money value printed or stamped on them and not their real value. This is because the printed value on the currencies denoted their purchasing power as assured by the government. People accept a coin or currency in payment not because they value the coin itself but because they have confidence in the authority that issued it.

As coins are heavy and bulky, larger payments are made in paper money issued by the paper legal authority.

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WHEN DID THE FIRST ALPHABET APPEAR?

ALPHABET -

The origin and development of any language can be traced back to the rudimentary symbols the primitive people used in their verbal interaction. These symbols, when used over a long period, take an established pattern thus giving rise to a new language, But the growth of a language does not stop at oral communication a script for writing is also to be developed. But when did the first alphabet that enabled man to express himself in writing?

The earliest people used pictures for writing which we call pictograph. The stone age people used this form in their writing. In pictograph, a particular sign represents an object such as a tree or a bird which in turn communicates a specific meaning or idea. Ideas could be communicated through picture writing in the sense that the picture of a bird might mean flying.

The ancient Egyptians also used picture writing. But this form had its limitations. It required thousands of pictures, which were also called characters, to symbolize a few things. This drawback of pictograph led to the discovery of signs that represented sounds used in verbal communication. These signs representing different sounds were grouped differently to form new words. But when did the sound-signs first appear which we now call alphabet?

About 3500 years ago, the Phoenicians in the eastern Mediterranean, invented the first alphabet. Later the Greeks and Romans developed their own alphabet which were improvements of the Phoenician script. In fact, the word 'alphabet' is derived from two words alpha (a) and beta (b) which were the first two letters in the Greek alphabet. The appearance of the alphabet made it easier to create thousands of words using a few alphabets. For example, there are only 26 letters in English alphabet but just imagine how many words we make out of these 26 letters. Pictograph lacked this advantage since one picture represented only one meaning or idea.

Now, most of the languages in the civilized world have their own alphabet but the number of letters in the alphabet and their pronunciation differ from language to language.

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DOES A BLACK CAT BRING BAD LUCK?

BLACK CAT  -

Have you heard someone telling you that a black cat crossing the road is a bad omen and you should not walk on the road if the cat has just passed by? Do you know why a cat in general and a black cat, in particular, is considered inauspicious?

Superstitions have taken various forms over the centuries but one of the most common superstitions that still prevails is that of the 'black cat'. Many people all over the world regard the site of a black cat as inauspicious.

The thought that a black cat is inauspicious in a mere superstition. This superstition goes back to a belief of thousands of years. The ancient Egyptians worshipped cats. They had a goddess called PASHT whose head resembled that of a cat. They believed that this goddess had nine lives. Whenever a black cat died in Egypt, its dead body was preserved as a mummy (the preserved corpse of a human being or animal). Remains of thousands of black cats have been recovered from a cemetery of Egypt. Killing a cat was then considered an offense, punishable with a death sentence. Thus people had a great fear of the sight of a black cat.

During the middle ages, witches and witch doctors always used the skull of a black cat to prepare mysterious medicines. As a result, people started thinking that a black cat brought bad luck and was a bad omen. People have believed in this superstition for many centuries. The truth is that no cat is inauspicious. The cat is a pet animal being domesticated from past 5,000 years.

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WHY DOESN'T FROZEN FOOD GET SPOILED?

FROZEN FOOD -

Have you ever wondered why we store perishable foodstuff in the freezer compartment of our fridge? It is because frozen food does not decompose for a long time and can be preserved for many months. There is an interesting fact about the discovery of the method of preserving food through low temperatures. In 1798, some explorers from Norway camped at the mouth of the river Lena in Northern Siberia. All of a sudden their dogs started barking aloud. When the explorers came out, they found the dogs digging in the snow. As they dug deeper they found the huge body of a dead mammoth. The flesh was dry. The explorers then hacked off a piece and cooked it. They found that it tasted like fresh meat. The last mammoths had died out about 30,000 years ago. This was a dramatic discovery. It meant that food could be preserved over such long periods. Since then, the man started preserving food at low temperatures.

What keeps food from getting spoiled at low temperatures? Food materials decompose because of the microscopic organisms called bacteria. At normal temperatures, bacteria flourish and multiply very fast and decompose the food. But at low temperatures, especially when the water present in the food material is frozen, the bacteria become inactive and stop growing. And thus, the frozen food can be preserved for a long time.

Nowadays, several techniques are being employed to preserve food materials. Among the important ones are the cold storage and freezing of foodstuffs. For the cold storage, many factors are to be kept in the mind. The type of food, the storage temperature and the amount of moisture in the storage room have to be taken into consideration. Cold storage temperatures range from 1Deg.C to 10 Deg.C. Freezing, however, is accomplished with dry ice (solid carbon dioxide), liquid air or nitrogen. Although freezing does not destroy the nutritive value of foods, some vitamins may be lost.

Domestic refrigerators are now widely used for food preservation. But, in a refrigerator, we can't preserve food for a long period. By using low-temperature techniques, great quantities of ice cream, frozen meat, fish, fruit, and vegetables are imported and exported throughout the world every year.

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WHAT IS THE BLACK MAGIC OF WITCH DOCTORS?

BLACK MAGIC -

In the recent times, witches and magic have become very popular due to the books of Harry Potter
. The phenomenon of magic and witch doctors is a very old one. In primitive societies, people had little control over supernatural forces, diseases, or natural calamities, etc. due to limited knowledge and lack of a scientific temper. They were afraid of natural elements because they could not control them. Occultism and mysticism dominated their lives due to ignorance.

The gradual development of science empowered men to deal with events and occurrences that were beyond their control earlier. In the primitive era, people were made to believe in them to resolve their problems. These practices gave rise to a class of people known as witch doctors, black magicians, tantriks, etc. who claimed to have mystical powers to control and influence the supernatural forces. Even today are found in certain primitive societies and villages. Among the practitioners of mysticism, the witch doctor was considered to be an important community member in a tribe. He was able to predict the weather, spot out a thief or a killer. He could treat illness by his magical powers and communicate with the dead.

Witch doctors were supposedly armed with black magic. He used it to frighten people with his power and make them follow his wishes. If he wished he could bring a curse on others, could make the crops fail, cause illness to children, or make people die. He used a variety of methods to curse people to death. Sometimes he made a small figure of the man and stuck pins in it or wound the rope around it. At times, he would get some man's hair or nail cuttings and bury them. As they decayed, the man died a slow death. People believed that he could extract blood and organs with his supernatural powers.

Witch doctors often used herbs and plants for curing illness and purifying water for curing the infection. Sometimes he would sprinkle water on a magic stone. He would chant magical songs, prayers, and dance in a weird manner to impress people. He would even dress up in bright-colored clothes and wear masks or paint his face. Some witch doctors wore hides of the animals. He hypnotized people to make them believe that he was responsible for their good luck. However, most witch doctors are quacks, they have no real power. Unfortunately, many innocent people are still victimized because of their belief in witchcraft.

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WHY DO WE DREAM?

DREAM - 

We spend about one-third of our life in sleep. Sleep is essential for the good health of both mind and body. Sleep is a state of unconscious rest. Even the conscious part of the mind is totally at rest, the subconscious part of the mind continuous working and produces dreams.

About five times during the night, we change from periods of deep sleep to periods of light sleep. And as morning approaches, the periods of light sleep become longer. We dream during the periods of light sleep. In the dream, we make rapid eye movements and some body movements. If we wake up while we are dreaming, we can often remember the dream. No one really knows why we have dreams. But they appear to be an important part of sleep. Scientists have proved that almost everyone dreams three to five times during an 8-hour sleep. Those who claim that they do not dream, in fact, do not remember what they dreamt.

Most dreams are based on events that happened during the day. Others involve fearful sights you might have seen when you were young. In other dreams, wishes you have had for a long time are also fulfilled. Some psychologists contend that during this activity, the brain 'clears its registers' to prepare for the next day's conscious activities. During this period, the pattern of brain waves also changes. It is sometimes recorded for scientific observations. Its recording is called electroencephalogram.

According to some people, their problems have been solved during dreams. Kekule, a great chemist, gave the structure of benzene molecule after having a dream. He was very puzzled about the structure and one night in his dream, he saw a snake biting its tail while in whirling motion. That gave him the idea about the molecular structure of benzene. Some people believe that dreams can foretell the future. So far, scientists have not been able to fully explain this phenomenon.

Some dreams are pleasant, while others called 'nightmares' are related to our suppressed emotions, fears, desires, and needs.

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WHY IS HARD TO WALK UPHILL THAN DOWNHILL?

 UPHILL THAN DOWNHILL -

Generally while climbing up the stairs of a building, a person gets more easily exhausted, than while coming down. To lift heavy articles, greater effort is required. It is harder to walk uphill than downhill. Have you ever wondered why?

We know that our Earth attracts everything towards its center. This is known as the force of gravity of the Earth. It is the force of gravity that holds us on the surface of Earth. When we move away from the Earth's surface, we have to put in extra energy to overcome the force of gravity.

So while going uphill, our muscles have to do more work to lift the weight of our body against the gravity of the Earth. For this, the heart has to pump more blood to the cells. As a result, our lungs have to do more work to pump out the carbon dioxide from the heart, and to replace it with oxygen. Here, for a steep climb, we breathe at a faster pace. If we climb a mountain by two different paths one more steep, and the other less we would feel greater fatigue in the case of the steeper one.

In comparison to the energy required for walking on a horizontal plane, the total value of the extra energy needed for climbing is the weight of the body multiplied by the total height to be climbed. When we walk down a hill, very little energy is required because the body is carried down the slope due to the Earth's gravitational pull. This is why our muscles do less work, and we do not feel tired while walking down a hill.

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WHY DO HOT THINGS BURN US?

THINGS BURN -

An object is said to be hot if its temperature is more than our body temperature. If we touch such an object, heat flows from it to our body and we sense the difference in temperature. In case the object is hotter, it causes pain and may even burn our skin. Similarly, an object is said to be cold if its temperature is lower than our body temperature. When we touch it, heat flows from our body to the object.

We know that our body is made up of molecules., and these molecules are made up of atoms. At normal body temperature, these atoms are in motion or vibrating. The atoms vibrate slowly when cold but faster when hot. When we touch a hot substance with a fingertip, the fast-moving atoms of that hot substance accelerate the motion of the atoms of our fingertip. The molecules at the fingertip suddenly start to vibrate faster, causing pain and a burning sensation. It is the breaking up of the molecules that cause the burning sensation. To repair the damaged cells, blood circulation becomes faster in the affected area, and it is for this reason that the affected part becomes red.

When the temperature of the object touching the body very high, a large number of cells and nerves begin to break up. The hit of the substance dehydrates the cells of the skin and they disintegrate. This is called burning.

Sometimes, very hot substances destroy fats and bones. This causes deeper wounds in the body. The scars caused by such burning are removed by grafting the skin taken from other parts of the body. Burns are classified into four degrees. In first-degree burns, only the superficial layers of the skin become red. In second-degree burns, deeper layers are damaged and blisters are formed. In third- degree burns, all the layers of the skin are destroyed. In fourth-degree burns, not only the skin but also the tissues beneath it are damaged.

Burns are caused not only by heat but also by chemicals, acids, X-rays and radioactive rays.

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WHY DO WOMEN HAVE A SWEET VOICE?

SWEET VOICE -

You may have noticed that the voice of women is generally sweeter than that of men. Even boys have a feminine voice till the age of eleven or twelve years. But later it starts becoming deeper. the voice of girls, however, does not change much with age.

Normally, the age between eleven to thirteen years is known as the puberty age. During this period, some of our glands produce sex hormones. These hormones bring many changes in the bodies of boys and girls. In boys, they are responsible for the growth and appearance of the hair under arms, auxiliary hair, pubic hair and facial hair. The voice of the boys starts becoming deeper. Their bodies produce a hormone called 'testosterone' which is mainly responsible for changing the length and thickness of the vocal cords. This also affects the larynx. As a result, a man's larynx becomes larger than that of a woman. men have vocal cords longer than those in women. Due to this, the frequency or pitch of man's voice becomes lower than woman's and hence the male voice becomes deeper than that of a female.

Though this hormone is not produced in the girls, yet a slight change occurs mainly due to the further growth of their throat, mouth, nose, and upper jaw.

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WHO IS BRIGHTER : GIRLS OR BOYS?

BRIGHTER -

There is a difference of opinion on this question. People have various explanations; some say that girls are brighter than boys while others have the opposite view. Scientists have yet to establish a logical scale by which it can be established that one sex is smarter than the other. Here are some facts, which provide some insight into this question.

The average brain weight of males is slightly more than that of females, and also the average body weight of men is more, therefore, in both sexes, brain weight percentage to the total body weight remains the same. The difference in brain size is not of much significance.

Various tests conducted on groups of girls and boys produced the same results. In tests, dealing with skills, the average score for girls was better. In tests pertaining to technical and mechanical ability, boys fared better. But these figures are not very important because these may not be a good measure of peoples' abilities. besides, this is only an average data on certain tests, one sex may score more than the other but the results are almost same in other tests.

Girls and boys are treated differently right from their childhood. Girls are usually given dolls to play with, while boys get electrical and mechanical toys. Therefore, girls are generally less technical than boys. But now things are changing. Today girls and boys are working together in various technical and non-technical fields, and their capabilities are almost equal. It is, basically, the kind of upbringing and training that decides the ability rather gender considerations. At present we have no scientific evidence by which it can be proved which sex is brighter. Neither sex has a monopoly on any special mental ability. It would be incorrect to judge brightness on gender grounds.

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HOW DID DIFFERENT SUPERSTITIONS BEGIN?

SUPERSTITIONS -

Superstitions have played a unique role in the human life right from the beginning of civilization. Even today, we may find many people who are superstitious about different things. Do you know how different superstitions began?

Ancient man could not explain various natural phenomena like thunder, lightning, and climatic changes. He knew little about the sun, moon, comets, and meteors. So he formulated his own theories about these phenomena, thus leading to the first kind of superstitious beliefs.

A superstition is usually born out of fear, which is contrary to reason and cannot be proved by experience. For instance, a comet was a mysterious phenomenon and was considered unlucky - a sign of imminent plague or war. People also believed that if one looked at the moon for a long time, he would get 'Moonstruck'. In fact, the word 'lunatic' has been derived from the Latin word 'Luna' which means moon. Similarly, farmers used to think that growing moon encouraged the growth of crops.

Superstitions were also built up around animals. In Egypt, cats were worshipped as sacred animals. In Europe, it is thought very lucky to have a black cat walk across one's path. In North America, the reverse is true. In India, a black cat crossing your path is considered as a sign of bad luck. The hooting of an owl is a sign of approaching death, and so on.

Over the centuries, superstitions about 'lucky' and 'unlucky' numbers also developed. For example, 13 is considered to be an unlucky number throughout the world.

Ancient people in Scandinavian countries believed that thunder and lightning were caused when their god 'Thor' threw His hammer at His enemies.

Sneezing is considered a bad omen. When someone sneezes, people often say 'God bless you'. With the advance in science, man has come to understand more about the world around him. But somehow the old beliefs continue to have their hold on people.

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HOW DID THE PRACTICE OF SHAKING HANDS BEGIN?

SHAKING HANDS -

People shake hands more frequently today than they did a few hundred years ago. In ancient times, the hand was considered as a symbol of power and strength. Primitive man used it to kill animals or fight against his enemies. The extended hands were taken to be a gesture of goodwill and friendship by ancient people.

The practice of shaking hands probably originated in ancient Greece. Greeks prayed before their gods with raised hands - a gesture of devotional acts in honor of the deity.

Nowadays, the handshake has become the most accepted form of greetings and occurs in the most varied cultural areas of the world with a few exceptions The Japanese, for instance, normally do not shake hands; they bow and the degree of bending is related to the amount of respect due to the person being greeted. In India, the traditional form of greeting is namaste with folded hands. In the Middle East, people exchange greetings by kissing gently on each other's extended hands.

However, with the passage of time and the influx of Western culture, these forms of greetings are not a rule everywhere although these traditions are still in existence among a large number of people in different regions.

A handshake can reveal one's hidden personality. A firm but smooth grip is considered the best handshake. It sends a message of warmth and friendliness. Handshaking usually accompanies all acts like an introduction, farewell, gratitude and congratulation. It is customary to shake every individual hand when formally joining or departing from groups.

The record number of hands shaken by a public figure at an official function was 8513 by president Theodore Roosevelt of U.S.A. at a New Year's day function on January 1, 1907. However, Scottkillon of Canada holds a handshaking record with over 25000 visitors in just 8 hours at the Exhibition of Expo-92 in Seville.

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HOW DID VARIOUS RELIGIONS ORIGINATE

RELIGIONS -

You must have heard of many religions co-existing in the world today. But have you ever wondered how the major religions originated? It is difficult to say which religion was the first to originate. However, the story of their origin is very interesting. From the beginning of civilization, the man has been worshiping many powers in the hope that they could protect him from different threats in day-to-day life. The man has also been worshipping things which he feared. For this purpose, he selected some powerful or ideal objects for worshipping. A particular spiritual power or ideal was first called a 'sect' and later on 'religion'. Now, the question is: how did the various major religions of the world originate?

Hinduism is not a codified religion and its origin cannot be attributed to any one person or deity. It is basically a way of life coming down from the original Aryan settles in the Indus valley. Buddhism started around 2500 years ago as a result of Gautam Buddha's teachings.

The principal religions in the world today are Hinduism, Buddhism, Confucianism, Taoism, Shinto, Islam, Judaism and Christianity. There are more than 3000 million followers of these major religions. They constitute three-fourths of the world's total population. The approximate number of followers of the different religions is as follows: Christianity 1000 million; Hinduism 520 million; Buddhism 230 million; Confucianism 275 million; Taoism 30 million; Taoism 30 million; Islam 520 million; Judaism 15 million.

The followers of the Chinese philosopher Confucius founded Confucianism. The Tao religion originated from the book Tao Te Ching, written by Lao-tzu in the 6th century B.C. The Shinto religion is the ancient religion of Japan. Similarly, Prophet Mohammed started the Muslim religion (Islam). Likewise, different prophets started in other religions.

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WHY DO PEOPLE GET MARRIED

MARRIAGE -

Marriage is the legally & culturally sanctioned union of a man and women. The basis of marriage varies considerably in different societies.
Why do people get married and how do marriages take place in different customs?

In most marriage ceremonies, customs or contracts involve a set of rights & duties such as care and protection. The couple promise to love and care for each other as long as they live. They formally accept each other as husband and wife and often exchange rings and garlands as symbols of their vows. It is also expected that children born of such union will continue the respective family line.

There are, generally, two types of marriage - civil marriage & arranged marriage. In most countries, people can choose either civil or religious marriage ceremony. In the Indian subcontinent, the ceremony may be held at the house of bride to be solemnized by a priest or holy man. In Western countries as well as in some other parts of the world including India, the ceremony often takes place in Churches, Gurudwaras or Temples.

It is also a tradition in some societies, particularly in Asian regions, for the bride to bring a dowry for her own wealth for groom's family. The ill-effects of such a practice can cause a great deal of tension where mutual understanding does not always work between the families of bride and groom.

In India, marriages are arranged generally by the bride and groom's parents, or through the marriage bureaus and marriage negotiators. With the advent of modern trends, the number of civil marriages is also rising. These trends have provided better legal status for women within marriage. In Western countries, registration of marriage is obligatory.

Weddings are a time of great celebration & festivity. Guests bring gifts for bride & groom and wish them a happy conjugal life. The bride & groom wear beautiful dresses that are specially made or purchased. The bride is also adorned with glittering ornaments.

marriages are made in heaven

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