World Famous Scientists

By Rajeev Garg

Written in simple and lucid language, these biographical sketches of great scientists have been put together for ready reference. History of the world is replete with such instances of such men and women who went against all the odds and achieved great heights and changed the shape of the world. In fact, reading about the life-sketch of a scientist and his achievements, has certainly great infotainment value. Besides, the lives of great men and women provide us inspiration to do things differently, and more confidently. For some people these inspirations have more importance than any other motivational factors. When we learn that Edison was a poor boy without any formal schooling or Faraday was an apprentice at a stationery shop we feel greatly motivated and think, 'if they could do it we can do it too!'. We find a new confidence in ourselves. In this respect the importance of these books, specially for children, can hardly be underestimated. Rather they could even be a part of the curriculum-- as at times they can prove so inspiring and motivate a person in such a way, that they could change the entire course of the life of a person. The main aim of this series is to expand the mental horizons of our readers and motivate them to achieve great heights in life. It is certainly a very valuable addition to the literature of popular science. The book can also prove to be an ideal companion during leisure time.

• Language: English
• Publisher: V&S Publishers
• Release date: Apr 1, 2012
• ISBN: 9789381384305

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Galielei Galileo

(Who wonderstruck people from the Leaning Tower of Pisa)

The story of Galileo and Leaning Tower of Pisa is well-known in the history of science. At the age of 23, when he was working as a lecturer in Mathematics in Pisa University, he read in a religious book that if two bodies of different weights are allowed to fall simultaneously from the same height, the heavy body will hit the ground first. In fact, this was a statement made by Aristotle. Galileo was the first man who proved this statement wrong.

Born: February 15, 1564, Pisa (Italy) Died:

January 8, 1642. Arcetri (Italy)

For this he Selected the 180 feet hign Leaning Tower Of Pisa. On the demonstration day, Galileo went up to the seventh floor of Pisa Tower with two metal balls weighing 100 pounds and 1 pound respectively. Thousands of people had turned up to witness his experiment. Among the crowd were many professors and students of Pisa University. Many superstitious spectators had blind faith in Aristotle’s statement given thousands of years earlier. They were freely abusing Galileo.

Galileo put both the balls on one edge of the roof very carefully. Some people among the crowd became curious, but most spectators were whispering with each other that this man would prove to be a fool very soon by his own experiment. Galileo dropped both the balls simultaneously. The people were wonderstruck when the two balls hit the ground at the same time. In this way, many years old superstition was proved wrong scientifically. People may differ about the truth of this story. However, it is true that Galileo could understand many facts about gravitation and that is why he could prove the truth by his experiment.

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 who disproved many old notions by his experiments, although there were no sophisticated instruments available at that time. This Italian scientist right from his childhood was deeply interested in studying nature and science. That is why he could see every natural event with a scientific angle.

When he was 17 years old, one evening he went to Church to pray. It was getting dark and the caretaker was lighting the candles in the candelabra which hung from the roof by a chain. When he left it, it started swinging to and fro. Young Galileo observed it keenly and noticed that the time taken in each swing was the same. There was no watches during those days to measure the timing, but being a medical student he knew that the beat of the human pulse is fairly regular. To prove his observation he counted the number of pulse beats for each swing. He observed that each swing, whether big or small, took the same time. On this basis he made an instrument which is known as pulse meter. Later his son Vinsenji made the wall-clock on this basis. This has developed into today’s pendulum clock.

Galileo fabricated the first telescope. He has written in one of his books that when the news of his telescope reached Venice, the king Sing Aroia called him. The whole court was surprised to see this instrument. Many people went up to the top of the Venice Church and saw the ships nearly 10 times nearer with the help of this instrument.

Galileo throwing the balls from the top of the Pisa Tower.

For about a month his telescope was tested by many people. With this instrument Galileo later explored the universe. With his telescope, he saw the satellites of Jupiter. He also proved that our Milky Way is composed of millions of stars.

Galileo established the validity of the views of Copernicus. Copernicus had said that the sun is the centre of the universe, not the earth. Galileo also said that earth is not the centre of the universe, but like other planets it also revolves round the sun. When in 1616, he proved for the first time that the sun was the centre of the universe, and the earth revolves around the sun, he was summoned before the officials of the Church and was warned to stop this propaganda. Due to this binding he did not give any public speech till 1630.

After that Galileo published his famous book Dialogues Concerning the Two Principal Systems of the World. In this book, Galileo expressed his views freely. This was an offence in the opinion of Church officials, and as a result the 70-year old scientist was summoned before the court once again. The authorities were willing to pardon him if he accepted that his statements were wrong.

It is said that after acute pressurisation Galileo rose to admit his folly and discard his scientific beliefs. But his conscience rebelled and he was overcome with repentance. He looked towards the ground and said in a broken voice: It is the earth which moves around the sun. For this defiance the aged scientist was put in prison. In 1637, Galileo became blind, and in January 1642 he passed away.

Evangelista Torricelli

(The Inventor of Barometer)

Torricelli’s name is usually associated with the invention of the barometer but, in fact, he designed many other things also.

At Florence in Italy, there is a museum devoted to the history of science. Among the exhibits is a telescopic lens which, to the casual observer, appears to be a well-developed lens a little over four inches in diameter. Even an optician will be surprised to know of the precision with which it is made. It is accurate to within a ten thousandth Of a millimeter; and WC Will be far more surprised when we learn that it was made in 1646. Its maker was Evangelista Torricelli. It was made at the time when no modern precision instruments were available. From this fact we can imagine the amazing degree of accuracy which Torricelli possessed.

Birth: October 15. 1608, Faenza (Italy)

Died: October 25 1647- Florence (itaiy)

Most of us know Torricelli as the inventor of barometer, but only few are aware of the interesting story behind this invention.

According to this story, Grand Duke of Tuscany got a well dug in the courtyard of his palace. The surface of water was about 40 feet below the courtyard level. In order to bring the water upto ground level, a hand-pump was installed with its pipe dipping in the well water. The pump handle was operated repeatedly, but the water did not rise in the pipe more than the height of 33 feet.

Initially it was thought that there was some defect in the pump. But on careful examination the pump was found to be in quite order. This incident was reported to the Duke but he also could not understand why the pump was unable to bring water to the ground level. In these days Galileo was the Mathematician to the Grand Duke. So the problem was referred to him. Galileo at that time was old and practically blind, so he asked his desciple Torricelli to look into it.

Torricelli was aware that a heavier liquid cannot be raised to the same height as a lighter liquid. He selected mercury for his experiment which is more than thirteen-and-a-half times heavier than watcr.,He calculated that if the measure of 33 feet is divided by 13.5, the equivalent height to which mercury might rise would be about 30 inches. Therefore, the use of mercury, he thought, would reduce the length of the experimental glass tube to only one yard.

To carry out the experiment, Torricelli took a glass tube of about 1 yard length with its one end closed. He filled it with mercury, closed the open end with his thumb and immersed it in a dish full of mercury so that the open end remained dipped in mercury. When he removed his thumb from the open end from below the mercury level, the mercury in the tube came down slightly and stood at a column length of about 30 inches. The upper part of the tube became empty. This empty column was named as ‘Torricelli’s vacuum.’ This experiment proved that water by hand-pump cannot be lifted to more than the height of 30 inches x 13.5, that is, about 33 feet and the apparatus used in this experiment later became the basis of evolving the barometer.

Torricelli’s barometer was taken to the peak of a mountain where the height of the mercury column was found to fall down. This proved that as we go above the surface of the. earth, atmospheric pressure decreases. On the basis of this experiment Pascal proved the statement of Galileo that air has weight. Today the barometer has become an essential instrument for weather men.

This great Italian scientist designed several types of telescopes, microscopes and made optical instruments with an almost incredible degree of precision. He was not only an experimental scientist but also a good mathematician. He discovered the fundamental formula for