My Science School

               Balloon flights have become a popular air sport these days though the number of participants is limited to a few. Balloon festivals are organized every year at different places all over the world as a competitive sport as well as for fun and entertainment. But who made the first balloon flight and when?

               The idea of a balloon flight first occurred in the mind of two Frenchmen when they watched smoke rising up inside a chimney. This led Joseph and Etienne Montgolfier to build the first man-carrying balloon. The balloon made by them was filled with hot air from a fire to provide the lift required for flying. It was the year 1783 when the people of Paris were amazed to see a sheep, a cock and a duck flying in a balloon made by Joseph and Etienne Montgolfier. But strangely the fact remains that though they made the first balloon they could not become the first air travellers. The honour of making the first balloon flight is shared by two brave men, J.P. de Rozier and Marquis d’ Arlandes. This historic flight carrying these two men was made in November, 1783. With this began the era of flying.

               But a balloon flight of this kind depended on wind blowing and the balloon flew in the direction of the wind. To overcome this drawback the first powered flight was made by fitting an engine to a balloon in the year 1852. Henri Gifford of Paris made this airship with a balloon fitted with hydrogen gas for lifting the balloon. A platform was attached below the balloon through wires and a small steam engine was fitted on this platform. The airship could be moved forwards with the help of a propeller run by the engine. This was the fore-runner of the more advanced airships and the later day aeroplanes which were run by electric and petrol engines.

               There are some interesting facts about the recent history of ballooning. A balloon called Miss Champagne rose to a height of 50 feet with 61 passengers on board on 19 Feb 1988.

               The Dutch balloonist Henk Brink made a balloon that reached a height of 328 feet with 50 passengers on board on 17 August 1988 which lasted for 25 minutes. 

               Dr. Subrahmanyan Chandrasekhar was a world famous astrophysicist. He was awarded the Nobel Prize for physics in 1983 for his outstanding researches in the field of astronomy related to the structure and evolution of stars. He shared this prize with an American professor William Fowler. Do you know why he received this honour and what are his contributions to the astrophysics?

               Prof. Chandrasekhar was born on Oct 19th, 1910 in Lahore. He was educated at Presidency College, Madras University. He got his doctorate from Trinity College, Cambridge. From 1933 to 1937 he worked on stellar evolution. His genius is established from the fact that he became a Fellow of Trinity College at a young age of 24. And at the age of 25 he had put forth his theory on dying stars which startled the whole world.

               In 1938 he became an Assistant Professor in Chicago University and in 1953 acquired American citizenship. In the same year he was given the Gold medal of Royal Astronomical Society.

               In 1947 Dr. Chandrasekhar became a Professor in Chicago University and the Morton D. Hull Distinguished Service Professor of Astrology in 1952. His genius is evident from the fact that his book An Introduction to the study of Stellar Structure, published in 1939 is still used as a reference book for students of astrophysics all over the world.

               In 1973 he was made a member of the Swedish Academy that awards the Nobel Prizes. His findings on White Dwarfs are internationally acclaimed. ‘Chandrasekhar Limit’ that deals with the limiting mass of the stars is again an epoch making discovery by him.

               The Mathematical Theory of Black Holes was his most important work, published in 1983. His latest book was Newton’s Principia for the common reader. Prof. Chandrasekhar passed away as an American citizen in the year 1995, within a few weeks of the publication of this book.

 

               Srinivasa Ramanujan was one of the greatest mathematicians India has ever produced. His contributions to the theory of numbers brought him worldwide acclamation. He was born in a poor Brahmin family of south India on 22nd December, 1887. Due to lack of scope, he started his career as a clerk. In his spare time he used to devise mathematical Problems himself and solve them.

               When he was 15 years old he obtained a copy of George Shoobridge Carr’s Synopsis of Elementary Results in Pure and Applied Mathematics. Having verified the results in Carr’s book, Ramanujan went beyond and developed his own theorems. In 1903 he secured a scholarship from the University of Madras. But since he devoted himself fully to mathematics and neglected other studies it was forfeited the following year.

               But undeterred, Ramanujan continued with his work in extreme poverty without employment. He got married in 1909 and began to search for a permanent employment. He obtained a clerical post with the Madras port trust.

               Ramanujan published his first research papers in the journal of the Indian Mathematical Society in the year 1911. His genius slowly gained recognition and in 1913 he began a correspondence with the British mathematician Godfrey H. Hardy that led to a special scholarship from the University of Madras and a grant from Trinity College, Cambridge. In 1914 Ramanujan went to England, where Hardy tutored him privately and collaborated with him in some research.

               Ramanujan’s genius was unrivalled. He worked out the Riemann series, the elliptic integrals, hyper geometric series, and the functional equations of the Zeta function and his theory of divergence series. In England, Ramanujan made further advances, especially in the partition of numbers. His papers were published in English and European journals. In 1918 he became the first Indian to be elected as a Fellow to the Royal Society of London.

               In 1917 Ramanujan got tuberculosis and so he returned to India. He died at Chelput in Madras on 26th April, 1920. 

               In the study of elementary Geometry we all are familiar with the concept of “Pythagorean Theorem”. This tells us that for any right angled triangle, the square of the longest side of the triangle (hypotenuse) is equal to the sum of the squares of the lengths of the other two sides.

               But do you know who invented this famous formula that still is the basic concept of the geometrical studies on triangles? He was Pythagorus, the Greek philosopher, mathematician and astronomer. Pythagorus was born during 500 B.C. in Samas, Greece, near the present city Metaponto in Italy. He migrated to South Italy during 532 B.C. to escape the tyrannical rules those prevailed there.

               But his inquisitive and probing mind always thrived him to share his ideas and thinkings among the people. These desires ultimately led him to establish an Academy at Carton — presently known as Crotona to achieve his goals. His teachings on ethics, politics and brotherhood had a great effect over the people there. His thoughts and ideas were flourished throughout most parts of Italy and Greece. But all these eventually died out towards the end of 4th century B.C., largely because of opposition from some quarters for some reason or other. But apart from his philosophical thinkings, his contribution is also credited with the mathematical concepts of the functional significance of numbers. He, in fact contributed to the development of mathematics and geometry in addition to his ideas on Western philosophy. It is an established fact that his ideas greatly influenced the thinking of Plato and Aristotle.

               In the scientific world, his theories on geometry, mathematics, astronomy, sound behaviours etc. were gratefully acknowledged. The famous astronomer, Copernicus for instance, described Pythagorus as a fore-runner of the suggestions put forward by him that earth and other planets rotate in orbit around the Sun.

               During 493, B.C. Pythagorus died at the age of 83.

 

               From the primitive age man has always known and feared earthquakes. We know about the large scale devastations they caused. Do you know who first invented a device for registering and detecting the intensity the earthquakes?

               He was Chang Heng of China. In 132 A.D. the device for registering seismic activity was invented by him. The device had a number of metal balls around the rim of an urn. It was arranged in such a way that an earth tremor would disturb a central column, operating a mechanism that dropped one of its ball into a metal holder causing a noise. The direction of the earthquake could be worked out by seeing the balls that fell and that did not.

               From this primitive device the modern sensitive seismographs evolved and a science has grown up with them known as the seismology or study of earthquakes. The Greek word Seimos means “a shaking”.

               Within the past hundred years there have been many advances in the design of the device called “Seismographer”. Seismographers give a record of movement and waves of the earth’s crust at their location. There is now seismic recording equipment fixed in every country — making continuous recordings. A heavy inert weight is suspended in the equipment by a spring and attached to this is a fixed pen that is in contact with paper on a rotating drum. During earthquake the instrument’s frame and the drum move, causing the pen to record a zigzag line on the paper. The pen does not move.

                These lines indicated the intensity and location of the earthquake. In modern observatories, at least two or three seismographers are installed. Each one is meant for monitoring the horizontal and vertical movements of earthquakes to measure and locate the exact centre of earthquake. It has not possible yet to design a seismograph to measure faithfully the movement of earth’s crust in every direction at once in response to seismic waves. However, it seems possible that earthquakes may soon be within man’s control to some extent. 

               An atom is made up of three types of elementary particles called electrons, protons and neutrons. The neutrons and protons constitute the nucleus of the atom while the electrons revolve around the nucleus in different orbits. Neutron is a subatomic particle that does not have any electric charge. Protons and electrons however carry equal positive and negative charges respectively but neutron has no such charge. The mass of the neutron is slightly greater than that of the proton. Do you know who discovered the neutrons?

               Neutron was discovered by a British Physicist named Sir James Chadwick. In the early 1900s, scientists were aware that an atom contained electrically charged particles called electrons and protons. Scientists believed that there must be uncharged particles also in an atom. In 1932, Chadwick showed that the radiation from the element beryllium, caused by the bombardment of alpha particles is actually a stream of electrically neutral particles. He called these particles neutrons. He also studied some other properties of these particles. Neutrons directly emitted from atomic nuclei are termed as fast neutron.

               Chadwick also explained the existence of isotopes. An isotope of an element has the same number of protons but different number of neutrons. It has, therefore, a different atomic weight. In 1935, Chadwick was awarded Nobel Prize for physics. Chadwick did pioneering work in the field of nuclear chain reactions. He played an important role in the development of the first atomic bomb during World War II.

               From the studies carried out on neutrons it has been found out that a free neutron which is outside a nucleus is unstable. On an average, a neutron decays in 12 minutes. This length of time is called half life of the neutron. Inside the nucleus, the neutrons are usually stable. When they decay inside the nucleus, that substance becomes radioactive. Beams of neutrons have high penetrating power and therefore they have high damaging effect on living tissues. Because of this, scientists working in nuclear establishments have to wear protective shields as a protection against harmful radiations.