Category Great Scientist

          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.

          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.