My Science School

               ‘Genius is one percent inspiration and ninety-nine percent perspiration’. Thomas Alva Edison, the greatest inventor of all times, is the most suitable example of his own saying. This great outstanding US inventor had the credit of making 1001 inventions. Can you imagine a world without electric light, recorded music, cinema etc., which are the contributions of this great genius?

               Edison was born on February 11, 1847 at Milan, Ohio. His father was an incharge of a light house at Lake Huron. Although he could not continue his studies in his school, he was very inquisitive from his boyhood to learn by understanding. When he was only ten years old he set up a laboratory in the basement of his father’s working place. He loved to mix liquids and powders to observe the reactions.

               At the age of 12, he began selling newspapers and candy in trains. As a very keen observer he learnt some preliminary techniques of telegraphy from the Station Master, which led him later to work as a roving telegrapher. During his stint as a supervisor in a Telegraph company he created a stock printer. With the money received from it, he set up a laboratory for carrying out his experiments and research work. In subsequent years he invented phonograph - the machine for recording and reproducing sound. Edison thus had made man’s voice immortal. In 1878, he demonstrated the light bulb - a carbon filament electric bulb. 

               While experimenting on electric lamp, he discovered an important scientific principle known as ‘Edison effect’. This discovery led to the invention of electron valves and the modern electronics industry rests on this principle. In 1882, he set up a power generating station which supplied power to a few residents of New York City. Later he developed the kinetograph which was the first step towards motion picture camera. Cinema houses are here today because of the inventive genius of Edison. His other inventions include the spheres of X-rays, telephone and other electronic items. His inventions made him one of the richest men in America.

This great genius passed away on 18 October, 1931.

 

 

          Galileo, even after 350 years of his death, is still considered as one of the greatest scientists of the world. He was the first man to disprove many old notions about nature and to use modern scientific methods.

          He was born in the town of Pisa, Italy, in 1564. His father was a merchant and taught music in his spare time. Young Galileo was a talented boy, interested in music and painting. He used to make scientific toys in his childhood. He was a keen observer. Galileo studied at the University of Pisa.

          When in an evening he went to chapel to pray, it was getting dark and the caretaker was lighting the candles in candelabra which hung from the roof by a chain. When he released it, it started swinging to and fro. Young Galileo observed it keenly and noticed that with each swing it covered shorter distance. Galileo felt that although the distance of the swing was becoming less and less, yet the time taken in each swing was the same. There was no watch during those days. It was a problem for him to test his idea. Immediately an idea flashed in his mind. He knew that the beat of human pulse is fairly regular. He felt his own pulse and then counted the number of beats for each swing. To his great delight his observation seemed to indicate that his idea was correct. This discovery was used 60 years later in making the pendulum clocks.

          At the age of 23 Galileo became Professor of mathematics at Pisa University. After two years of teaching he was declared the best teacher. During those days he had read in a religious book that if two bodies of different weights are allowed to fall simultaneously from the same height, the heavier body will hit the ground first. He proved this statement to be wrong. From the leaning tower of Pisa he dropped two spheres, one of 100 pounds and the other of 1 pound simultaneously. This great experiment was seen by thousands of people. It was highly surprising to everybody that both the spheres hit the ground at the same time.

          Galileo made the first telescope of the world. He observed many heavenly bodies through it. With his telescope he saw the satellites of Jupiter and studied many stars of the Milky Way.

         Galileo established the validity of the views of Copernicus. Copernicus had said that the earth is not the centre of the universe but it is simply a member of the solar system. Galileo proved for the first time that the sun was the centre of universe and that the earth revolves around the sun. These views of Galileo were published in a book.

          His discoveries offended the leading churchmen because he had disproved many notions cherished by religious people. As a result he was put in prison. By that time he had become quite old. The authorities were willing to pardon him if he accepted that his statements were wrong. He was pressurized; Galileo bowed before the authorities and said, “I am in your hands. God only knows the truth, but I feel earth revolves around the sun”. Later in 1637, Galileo became blind and in January 1642 the great discoverer died.

 

          Albert Einstein, the mathematical physicist famous for his Theory of Relativity, is called the father of modern physics. He was born on March 14, 1879 at Ulm in Germany. When he was only one year old, his family moved to Munich. Einstein spent his boyhood there. He was shy and dreamy in his childhood. Since his mother was fond of playing piano, he also learnt it from her.

          Right from the beginning, Einstein showed a keen interest in scientific instruments. He was very sharp in mathematics, but just mediocre in other subjects. When he was fifteen, his family moved to Italy. From there he was sent to the Zurich University of Switzerland. Here his genius began to flower. He turned to be an extraordinary scholar of physics and mathematics.

          He completed his education in the year 1900. He wanted to become a teacher, but could not get a teaching job of his choice. Finally he joined the Swiss Patent Office at Berne as a clerk. He married a young Yugoslav science student, Mileva Marec. The couple had two sons.

 

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          Radium is one of the few metallic elements that constantly emit invisible radiations. Such elements are called radioactive elements and the radiations they emit are called ‘radioactive’ rays. There are three types of radioactive rays - alpha, beta and gamma rays. Radium, due to the emission of the radioactive rays, disintegrates and finally gets converted into lead. Half of this radioactive element gets converted into lead in 1622 years. This is called the ‘half life’ of radium. In the next 1622 years, half of the remaining substance decays into lead. This process continues indefinitely. The radioactive rays are so powerful that they can pass through different kinds of substances including the human body. These rays are very useful in the treatment of cancer. Do you know who discovered radium?

          Radium was discovered in 1898 by a French married couple, Pierre Curie and Marie Curie. The story of its discovery is very interesting.

          In 1896 Henri Becquerel discovered the phenomenon of radioactivity. He found that the uranium emits a kind of invisible radiations which are more powerful than even the X-rays. In 1898 Pierre Curie and Madam Curie, found that thorium also emits similar radiations. They thought that pitchblende, which is the ore of uranium, must contain some other radioactive substance too. They started refining pitchblende in order to obtain the new radioactive element. They had to work in a tin-shed because they could not afford a proper laboratory on account of limited means. Without caring for rains and storms, they worked day and night. Finally, they succeeded in extracting 100 milligrams of radium from several tons of pitchblende. They found that this new element was much more powerful than uranium.

          Pure radium is white in colour. It is quite heavy and thousands of times costlier than gold. The quantity of pure radium available in the world is very small. Radioactive rays are very harmful to the body. If handled carelessly its radioactive rays can cause bad radiation burns. There are 16 isotopes of radium. The most common is radium 226. It is used in medicine to destroy cancer growths.

 

          Enrico Fermi was a great Italian-American theoretical physicist. He was one of the chief architects of the nuclear physics. He was awarded the Nobel Prize for Physics in 1938 for his outstanding discovery of neutron-induced nuclear reactions.

          Fermi was born in Rome on 29th September 1901. He was a brilliant student and obtained his doctorate in Physics from the University of Pisa at the age of 21. His research was on X-rays.

          In 1926 Fermi became a full time Professor of theoretical physics at the University of Rome. In 1929, he was elected a member of the Italian Academy. In 1934 he succeeded in making a fundamental discovery in the field of physics. This was the result of 10 years of arduous research. He discovered that when elements are bombarded with slow neutrons, the material becomes radioactive and begins to emit radiation. In this process the element changes into a different material. For example, iron, when made artificially radioactive by neutron bombardment, turned into manganese. In this way Fermi found about 80 new artificial nuclei. 

           About this time, Italy, under Mussolini, was in the grip of a Fascist government. This affected Fermi directly because his wife was a Jew. So he wanted to leave Italy. Fortunately at this time (in 1938) he was named for Nobel Prize. He was given permission to go to Sweden to receive the award. Fermi left Italy with his family never to return. After receiving the award, he went to U.S. and became a citizen of United States. Subsequently he became Professor for Nuclear Studies at Columbia University.

            In 1942, during World War II, Fermi built the first atomic reactor in an empty Squash court in Chicago. Here he set off the first man-made nuclear chain reaction. Later he helped to develop the atom bomb.

 

          The invention of wheel has proved to be one of the biggest blessings for the mankind. It is used in almost all modes of transportation: trains, buses, trucks, cars, aeroplanes, scooters, cycles, rickshaws, bullock carts, etc. It has become very easy to cover long distances in a short time, thanks to the wheel.

          Before the invention of wheel, man himself carried the load. Later on, he started taming the animals like oxen, donkeys, horses and camels and used them for carrying their load. Gradually man started carrying load by dragging wood planks with the help of animals. Stone Age people may have learned to roll loads along on logs. The oldest known wheels looked like slices cut across a log with a hole in centre. Each solid disc was made of tree parts. After this invention, two wheels were joined by an axle and the axle was fastened to a platform of wood. This was the first crude cart of the world. In this cart both the wheels and the axle used to move.

          Later, a sophisticated version of wheel was developed. Wheels were made in ancient Mesopotamia (modern Iraq) between 3,500 BC to 3,000 BC. The picture of a cart wheel appears on some clay tablets from Mesopotamia dating 3,500 BC. About 2500 BC wheel was in use in Indus valley also.

         The next improvement in the use of wheel was fastening the axle to the vehicle and letting the wheels spin freely. The first wheeled vehicles were bullock carts, war- chariots and four-wheeled carts of the gods. Gradually the spoke wheel was invented in Asia about 2000 BC. This reduced the weight of the wheel considerably.

          With the passage of time, numerous improvements have been made in the design of wheels. Today, we have the rims and spokes of the wheels made of iron. Rubber tyres and tubes are put around them. To make tyres durable, nylon fabrics are used in rubber solution. Rubber tyres are so designed that these can have firm grips over the road surface to avoid skidding. Now wheel has become lighter, more efficient and long lasting. The invention of an unknown genius carried us a long way along the path of technology and civilization. 

          Archimedes, the “Father of experimental science”, was an ancient Greek physicist and mathematician. He was born at Syracuse in Sicily in the year 287 B.C. and educated in Alexandria. His teacher was a disciple of Euclid. The principles of science discovered by him are still taught to students. The famous “Archimedes’ Principle” tells us that if we weigh an object in air and then weigh it again when submerged in a liquid, it will apparently lose weight equal to the weight of the liquid it displaces.

          The story of discovery of the famous Archimedes’ Principle is very interesting. Once King Heron of Syracuse gave him a crown made of gold. He suspected that it was alloyed with silver. He asked Archimedes to test its purity without damaging it. It was absolutely a new problem for him. Interestingly he found its solution one day in a very peculiar manner. When he entered his bathtub, he found that his body displaced some water, and the water level in the tub rose. He then jumped out and ran down the street, naked, shouting “Eureka! Eureka!” (“I have found it! I have found it!”). He filled a vessel with water and dipped the crown in it. The water displaced by it was measured. Again he filled the vessel with water and dipped an equal mass of pure gold in it. The water displaced was again collected and measured. The amount of water displaced in the two observations was different. From this experiment he estimated the impurity in the gold crown. On the basis of this discovery he gave the method of finding out the relative density of different substances. 

          Archimedes also gave the laws of flotation of bodies and the principle of lever. He, for the first time, calculated the value of pi. In addition to these, he discovered the use of levers and pulleys and how to pump water uphill using Archimedean screw. The system is still used to irrigate fields in Egypt. He also designed war machines.

          Romans captured Syracuse in 212 B.C. At that time Archimedes had become quite old. One day while he was drawing some geometrical figure on the sand, one of the Roman soldiers asked him to accompany him. And when he refused, the soldier pulled out his sword and killed him. He was cremated with great honours. 

          Sir Isaac Newton is considered as one of the greatest scientists and mathematicians of all time. He was born on the Christmas morning of 1642 at Woolsthorpe in Lincolnshire. It was also the year in which the famous scientist Galileo died.

          At the age of twelve Newton was sent to school. When he was eighteen, he went to Trinity College at the Cambridge University. There he showed his brilliance in mathematics. In 1669 he became Professor of mathematics in the same college.

          Newton was very fond of making mechanical toys in his childhood. It is said that one day while sitting in a garden, he saw an apple falling to the ground. He began to wonder: “Why did the apple fall towards the ground? Why did not it go towards the sky?” Such questions puzzled him. He worked on this problem and finally gave his famous ‘Law of Universal Gravitation’. According to this law, everybody in this universe attracts every other body with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. He established the fact that the earth attracts all objects towards its centre. That is why anything thrown upwards falls back to the earth.

          Great scientist as he was, he solved many mysteries of the nature. He showed that the sunlight which appears white is in reality made up of seven colours. He could split these seven colours with the help of a prism. He also showed that the mixture of these seven colours produces white light. He also built the first reflecting telescope. His work on light and colour was published in 1704 in a book called Optics. He did monumental work in the field of mathematics. He gave the famous Laws of motion. He invented calculus. Newton’s discoveries were published in his book called Principia. It is one of the most important books of science ever published. On account of these researches Newton is called the ‘Father of Physics’.

          In 1689 Newton was elected as a member of parliament. In 1703 he was elected President of the Royal Society and was re-elected as president every year until his death. When he was 85 years old, he went to London to preside over a meeting of the Royal Society. But on his return he fell ill and he died on March 20, 1727.