Category Science

               The inconsequential number zero was a major invention which has had a tremendous impact on the history of mankind because it made the development of higher mathematics possible. Without the invention of zero higher mathematics would not have been developed to its present status.

               Although it is not known with certainty who invented it, yet there is no controversy about the claim that it was invented in India around 2nd-3rd century A.D. Right from the beginning of civilization, man has tried many different methods to write numbers. For this purpose, Greeks used letters of their alphabet and Egyptians, appropriate pictures. Romans used a complicated system. They used ‘X’ to represent 10, ‘C’ to mark 100 and ‘M’ for 1000. For 1 they used ‘I’, for 5 ‘V’, for 50 ‘L’ and for 500 ‘D’. They represented 4 by ‘IV’. If they had to write 1648, they wrote ‘MDCXLVIll’. This was indeed a complicated method.

               However long before the birth of Christ, the Hindus in India had invented a far better number system but without zero.

               Later zero was invented. Unlike many ancient systems, today we have a zero to represent nothing. It was introduced in the modern role by Hindu mathematicians. It was brought to Europe about the year 900 A.D. by the Arab traders, and is called the Hindu-Arabic System. In this system, all numbers are written within the nine digits – 1, 2, 3, 4, .5, 6, 7, 8, 9 and the zero (sunya). Here each figure has a value according to the place in which it is written. The Romans didn’t have a zero in their system.

               Zero has some peculiar properties. When it is added or subtracted from any number, the result remains the same. When any number is multiplied by zero, it becomes zero. It is the only number which can be divided by any other number, but it cannot divide any other number. The expression 0/0 is neither meaningless nor meaningful. In fact, it is indeterminate. Zero is similar to all other natural numbers.

               In a nutshell, zero is a number smaller than any finite positive number, but larger than any finite negative number. Division by zero is an undefined operation. It may be regarded as the identity element for addition in the field of real numbers.

               The invention of zero became the turning point in the development of culture and civilization – without which progress of modern science, industry and commerce was inconceivable.

            A hospital is an institution devoted to the care and treatment of sick people. Do you know when and how did hospitals come into being?

            The history of hospitals began in Babylonia, Greece and India. These early hospitals were temples. Very little medicines were given to patients. Hospitals existed in Ceylon (Sri Lanka) in 437 B.C. and were established in India somewhat earlier during the time of Buddha. Eighteen hospitals built by Emperor Ashoka in 3rd century B.C. are said to have some characteristics similar to modern hospitals.

            The advent of Christianity gave impetus to the establishment of hospitals. Their growth accelerated during the crusades which began by the end of the 11th century.

            Three persons – Florence Nightingale, Louis Pasteur, and Lord Lister contributed most to the growth of hospitals in modern times. Florence Nightingale known as the ‘Lady with the Lamp’ was a great reformer of hospital conditions and re-organizer of nurses training programmes.

            Louis Pasteur contributed a lot in germ theory and Lord Lister put his research in practice. Developments in anaesthesia made it possible to perform major and more difficult operations.

            The first hospital in North America was built in Mexico City in 1524 by Cortez. The French established a hospital in Canada in 1639 at Quebec City.

            During the 20th century, outstanding contributions have been made by scientists in the field of medicine and surgery. As a result, the number of hospitals has greatly increased. Today we have private hospitals, military hospitals, general hospitals and also specialized hospitals for mental diseases, tuberculosis, heart diseases, cancer and eye disorders etc.

            The largest hospital in the world is the District Medical Centre in Chicago, Illinois, U.S.A. It covers 478 acres and includes five hospitals, with a total of 5600 beds. At present China has the greatest number of hospitals — 61929 in 1989.

An elevator or a lift is a car that moves in a vertical shaft carrying passengers or freight from one floor to another in a multi-storeyed building. Most modern elevators are propelled by electric motors with the help of a counterweight through a system of cables and pulleys. Do you know who invented the elevator?

Elevator was not invented by one man or in a single day. Its development is a result of combined efforts made by several people.

The practice of lifting loads by mechanical means during building construction goes back to Roman times. The Roman architect-engineer Vitruvius Pollio in the 1st century B.C. had described lifting platforms that used pulleys and capstans, operated by humans, animals or water power. In 1800 A.D. steam power came to be used to operate such devices in England. In the early 19th century, a hydraulic lift was introduced. These lifts were used only to hoist freights because they were most unreliable.

In 1853, Elisha Graves Otis introduced a safety device and gave birth to the first passenger elevator. This was put into service in the Haughwout Department Store in New York City in 1857. It was powered by steam. It climbed five floors in less than a minute. Improved versions of the steam – driven elevators came into use in the next three decades, but the most significant progress was made after 1889. In 1894, push button operations were introduced. After that many design improvements were made.

Once the problems of safety, speed and height were overcome, attention was turned to convenience and economy. Soon more sophisticated elevators came to cater to the need of tall buildings. Their speeds were increased to 365 m per minute. Automatic operations were also introduced by the 1950s, eliminating the need of operators.

Continue reading “When was the elevator invented?”

               Hippocrates, a Greek physician, is known as ‘the father of medicine’. He was born on the island of Cos where he later founded the first school of medicine. He lived between 460 BC to 377 BC. Modern medical students make a promise to be ethical in their work which is known as the Hippocratic Oath.

               Doctors at the Hippocratic School of medicine were taught that diseases were the result of improper functioning of parts of the body, rather than of possession by demons as was believed superstitiously in those days. But Hippocrates and his followers did not know about the structure of the human body. They believed that diseases were caused by the imbalance of four vital fluids — blood, bile, phlegm and black bile. Hippocrates also pointed out that malaria and certain other diseases were associated with particular localities or climate conditions. 

               Hippocrates and other members of the school have written more than 50 books on medicine. Some of the descriptions of diseases in these books are very clear and accurate. In his writings, some of which may in fact be by other members of his circle, is found the important theory which tells that every disease is related to the natural law just like everything else and therefore should be carefully observed and treated accordingly. But this theory is not wholly accepted in modern medical science. However, no other medical books as scientific as these were written until modern times. 

            Sir C.V. Raman was one of the greatest scientists of India who was awarded the Nobel Prize in 1930 for his outstanding discovery in Physics. It was named after him and is known as ‘The Raman Effect’.

            Chandrasekhar Venkata Raman was born on 7th November, 1888 at Tiruchirappally in Tamil Nadu. Raman was a very brilliant student right from his childhood. After passing his matriculation at the age of 12, he was admitted to the Presidency College, Madras. From there he passed his B.Sc. in 1904 and M.Sc. in Physics in 1907 with the first position in the University. While he was a student in the Presidency College, he modified Melde’s theory on sound.

            In 1907 after passing a civil service competitive examination, he became the Deputy Accountant General in Calcutta. In 1915, he met Sir Ashutosh Mukherjee, the Secretary of the Indian Science Association. Raman joined this Association as a member, and started his research work. In the year 1917, he resigned from his post and became the Professor of Physics at Calcutta University. 

            During a sea voyage to Europe in 1921, he observed with wonder, the brilliant blue colour of the Mediterranean, and later the blue colour of glaciers. After returning to India, he experimented on the diffusion of sunlight during its passage through water, transparent blocks of ice and other materials. He then explained the reason for the blue colour of the ocean. His studies on scattering of light led him to the discovery of ‘Raman Effect’ in 1928. ‘Rama Effect’ describes the change in the frequency of light passing through transparent mediums. He used monochromatic light from a mercury arc and the spectroscope to study the nature of diffused radiations emerging from the material under examination. For this discovery, he was awarded the Nobel Prize in 1930.

            In 1933, he became the Director of the Indian Institute of Science, Bangalore. He held this post for 10 years. In 1934, he sponsored the foundation of the Indian Academy of Sciences, of which he became President. In 1943, the Raman Research Institute was set up by him. Then he conducted research work for the rest of his life. He died on 21st November, 1970 at Bangalore.

            Milking machine is a device used for milking the cows. The first milking machine was patented by an American engineer I.O. Colvin in 1860. It had four rubber teat cups which were connected to a vacuum chamber attached to the side of a pail. The chamber was similar in appearance to a bellows and a vacuum was created by pumping the handle after the cow’s teats had been placed in the rubber cups. It was gradually realized that continuous suction caused pain to the cow and often caused internal bleeding which contaminated the milk.

            In 1889 William Marchland of Kilmarnock, Scotland patented an elaborate suction milking machine. It also had some problems. Its improved version was produced by Dr. Alexander Shields of Glasgow in 1895. This model was very costly for the farmers. This was further improved in the early 20th century by several firms in Scotland.

            The modern carousel milking machine consists of a large slow-moving platform, powered by an electric motor, with places for several cows. As the cows approach the platform, they are placed at their own feeders and a milking machine is attached to each cow. The milk produced is collected in glass containers.

            Since the late 1960s the animal feeding methods in milking parlours have advanced dramatically. Many of the parlours are computerized and some include electronic sensors which pickup signals from small transmitters fixed around each cow’s neck and which reveal the animal’s feeding requirements. Automatic dispensers then provide the requisite ration.