from 'Icons from the world of science', by S.Ananthanarayanan - home page

J C Bose - the name of versatility

The invention that had the greatest leverage in the fantastic development of the 20th century, in all spheres, is certainly wireless telegraphy, which made possible ‘instant’ communication across continents. The credit for the invention is generally given to Guglielmo Marconi, but more and more people are now accepting that Jagdish Chandra Bose had publicly demonstrated the basis of the same thing in 1896, a full two years before the Italian! And although Marconi went on to perfect wireless, the research that Bose carried out laid the bases of microwave communication, which is at the heart of more advanced telecommunications developed many years later.

Jagdish Chandra Bose, was born in 1857, just a year before the ‘first war of independence’, the so called ‘sepoy mutiny’, in Myemsingh, a quiet village in the then undivided State of Bengal. His early education was in a village school, in the Bengali language, followed by school and college at St Xavier’s College, at Kolkata. University education in India was still in its infancy, colleges having barely started university courses in the 1860s. When J C Bose took his BA in Physical Sciences, in 1879, he may have been one of the earliest of Indians to be trained in the European tradition. It is remarkable that a few years later, he should forge into the vanguard of research in Physics, make contributions that shaped the world and be elected to as exclusive a body as the Royal Society!

After his BA in Kolkata, Bose went to England, at first to study medicine. But when problems of health prevented him from completing this course, he shifted to physical sciences and took his BA and B Sc from the Cambridge and London Universities in 1884. There are not many records of his career as a student, but one of his professors in Cambridge was the celebrated Sir Raleigh, who had done fundamental theoretical work on the scattering of electromagnetic radiation, like visible light. Bose’s subsequent work suggests that he had imbibed the atmosphere of experiment and discovery that was sweeping the scientific world at the time.

Bose returned to India in 1885, and began work as a professor of Physics at Presidency College, Kolkata. It is a measure of the precision of his thinking that when the college offered him a salary less than that paid to his European colleagues, Bose refused the salary entirely and worked gratis for all of three years. His protest was successful and he was finally paid the full salary, with arrears.

At Presidency College, Bose proved to be a gifted and popular teacher, with classes replete with experiments and practical demonstrations. His found Physics itself exciting and to convey this magic to his students he animated his lectures with example and anecdote and stratagems to bring out the unity of basic principles behind natural things. Many of his students went on to make important contributions to the sciences, a notable one being S.N.Bose, the statistical Physicist, after whom a family of elementary, subatomic particles, the Bosons, which follow Bose-Einstein statistics, is named!

What Bose found lacking in Indian colleges and universities at the time was facilities for research. His efforts to develop a facility in Presidency College were stonewalled for many years. But, indomitable of spirit, Bose set up a laboratory with rudimentary equipment in an abandoned bathroom in the Physics department and commenced serious original research!

An area of much interest at the time was the nature of electromagnetic waves. Electric and magnetic phenomena had been studied for a century and it was known that moving electric charges, or currents, had magnetic effects. This is the effect that is used to drive an electric motor, with the help of a current. The opposite, that varying magnetic fields could give rise to currents in conductors, as happens in a dynamo, was also well known. These effects had been refined to an exact mathematical theory, which went on to say that an electric charge that moved to and fro sent out a wave of combined electric and magnetic effects, or an electromagnetic wave. An example of such waves was ordinary visible light, which showed wave-like properties.

Taking off from the theory, Heinrich Hertz had demonstrated that varying electric currents did give rise to a combination of electric and magnetic effects, which moved out as ‘waves’. These waves behaved in all ways like ordinary light, but with a much larger wavelength. The dimensions of the waves of visible light are of a thousandth of a millimeter, while the man-made, Hertz waves had dimensions from centimeters to metres. Hertz waves then got scattered much less than shorter waves and could move ‘around’ small obstacles, much like the waves of the sea are not affected by a post sticking out of the water! This was an exciting phenomenon and there was much interest in applying this effect to convey signals over a distance.

It was hence in this area of the properties of Hertzian waves that Bose worked in that makeshift laboratory. He set up electrical equipment to generate alternating currents and ‘sparks’ of electricity, which would give off electromagnetic waves. While Hertz had used generators about a metre high, Bose used much smaller equipment, less than a centimeter across, to work with smaller, ‘centimetre’ waves.

Along with these generators of waves, Bose developed ways to detect the waves at a distance, when the waves would be much weaker. One kind of detector was loops or coiled wires, like antennas. This is suitable for detecting electromagnetic waves with long wavelength. But for the smaller waves with which Bose was working, he developed cavities and resonators, with the appropriate dimensions. And finally, to detect the waves, which were rapidly alternating, as a current that flowed in a single direction, he developed a device known as the junction detectors. These were sharp iron points pressing upon an iron contact, and they worked as detectors because these junctions could act like one-way gates for electric current.

A wave of electromagnetic radiation consists of electric and magnetic effects that are rapidly rising to a maximum in one direction, falling to zero and then rising to a maximum in the other direction. When such a wave resonates in a cavity, it sets up weak currents which alternate in direction in the same way. But when the wave impinges on the junction detector, which is connected to a power supply, it allows current to pass during one half of the alternating cycle, but not during the other, opposite half. The result is that a current, which is many times stronger than the wave received, flows through the junction, in one direction only, and the current can then be measured by an instrument!

Point detectors

During those years, J C Bose also developed detectors using galena crystals. These crystals are like the junctions, just described, except that the components involved are at the atomic level, in the structure of the crystal. The use of these crystals, in fact, was like the transistor technology that was developed many years later. In the words of Sir Neville Mott, Nobel Laureate in 1977 for his own contributions to solid-state electronics, "J.C. Bose was at least 60 years ahead of his time.”

Using this equipment, J C Bose conducted research on the properties of electromagnetic waves in the half centimetre region and the effectiveness of metallic tubes to conduct such waves, functioning as ‘wave guides’. This work, in fact was a very important contribution of J C Bose to the world of communications.

In the course of his researches, Bose developed an effective scheme for transmission and reception of millimeter electromagnetic waves. In 1895, Bose demonstrated to an excited audience of the Asiatic Society, at Calcutta, the wireless transmission of radio waves over a distance of 75 feet, through masonry, to ring a bell and to explode gunpowder! In 1896, after another such demonstration, the Daily Chronicle of England reported, "The inventor (J.C. Bose) has transmitted signals to a distance of nearly a mile and herein lies the first and obvious and exceedingly valuable application of this new theoretical marvel."

These distances were nearly the limit to which millimeter waves could be used. Transmission over longer distances required waves of longer wavelength, a development initiated by A.S. Popov in Russia and given a practical shape by Marconi in 1898. But the point is that although the commercial and practical success was of Marconi, the engineer, from the standpoint of a scientist, it was J.C. Bose who had developed and demonstrated this technology. In fact, a vital component of the arrangement was the device that receives the wireless signal, known as the coherer. It is now recognized that the design of the coherer used by Marconi for celebrated demonstration of 1897 was none but what was devised by Bose.

It is not that Bose had not recognized the commercial value of his discovery. He had immediately sent details of his work to Lord Raleigh and Lord Kelvin, in England and they had recognized the worth of their former student and colleague’s breakthrough. Bose also went on lecture tours in Europe and USA in 1896-97 and 1901-02. But at no time did he make any secret of the design of the coherer, which he felt anyone was free to use and exploit if he so wished. In a letter to Rabindranath Tagore, he said, "...the proprietor of a reputed telegraph company...came himself with a Patent form in hand...He proposed to take half of the profit and finance the business in the bargain. This multi-millionaire came to me a begging. My friend, I wish you could see that terrible attachment for gain in this country, that all engaging lucre, that lust for money and more money. Once caught in that trap there would have been no way out for me."

J C Bose at the Royal Institution, London, 1897

But going beyond the spectacular transmission and detection of radio signals, for the credit of whose discoveries some may find reason to squabble, J.C. Bose’s work in that last decade of the 19th century greatly advanced the understanding of short electromagnetic waves and the use of metallic cavities and tubes for their transmission, and horns and curved surfaces to guide them. Decades later, when the conventional wireless technology itself disclosed its limitation, these principles became relevant in the development of microwave communication, radar, digital signals over cables and optical fibre technology.

While the commercial value of what he had discovered was getting taken over by trade and industry, Bose trained his attention on the academic issue of the millimeter waves itself. During his presentation of his experiments before the Royal Institution, in 1897, he had already started proposing that millimeter waves should be getting generated by the sun and speculating on the reasons for our not receiving any of them! Perhaps there were components in either the solar or the earth’s atmosphere that were responsible, he suggested. The concepts, again, were precocious and prophetic, for microwave radiation from the sun was discovered in 1942 and in 1944, it was found that water vapour strongly absorbs radiation in the 1.2 mm range.

A deep interest of Bose, ever since his BA in Kolkata was the science of botany, the study of plants. During the early 1900s, he used the expertise that he had developed in making precise and minute measurements and his knowledge of electromagnetic waves to investigate the effect of these waves on plant growth.

Using the same sophisticated methods of investigating the inanimate and invisible properties of light and radio waves, Bose studied the reaction of plant forms to radiation, temperature, trauma (injury), sounds and all physical conditions, generally. Researchers in biology are usually hampered by not being specialists in the instruments they use, even microscopes. The result is that the content of research is limited by the training of the researcher and these aspects of plant behavior are not examined, by default. But in the case of Bose, we have an expert in instrumentation entering the field of botany, with the added credentials of a trained botanist.

The outcome was a formidable catalogue of data and also the birth of the field of plant biophysics. The work was widely acclaimed and greatly influenced the course of research in the life sciences. At that time, the world of medicine and psychiatry was seriously examining the physiological or purely chemical-electric origin of emotions. The work of Bose raised the opposite question, that if plants underwent similar chemical-electrical changes when exposed to stimuli, could it not be held that they experienced emotions?

The assertion may today appear to be facetious and not strictly scientific. But the question raised is in fact totally scientific, in not discarding an idea without objective examination of the facts. Whether or not we agree that the ‘irritability’ of plants, a subject studied by Bose, corresponds to the annoyance that we feel when exposed to noise, there is no gainsaying Bose’s painstaking measurement of changes in electrical and chemical activity in the cells of plants under all kinds of environmental pollution!

All through the early part of the 20th century, J C Bose traveled widely and lectured about his findings and conjectures in varied forums. And everywhere, he was received as a remarkable man of science from India. In 1917 he was knighted by the British Crown and in 1920, he was elected Fellow of the Royal Society. He retired from Presidency College in 1915, but was appointed Professor Emeritus and the Government awarded him a pension of Rs 1,500 a month, a formidable purse for the times!

Apart from his versatile scientific ability, J C Bose was also aesthete and man of the arts. He was a good friend of Rabindranath Tagore and was president of the Bengali Sahitya Parishad, the Bengali Literature Society. He had literary friends further afield too and was on intimate terms with the English playwright, George Bernard Shaw, the French writer Romain Rolland, sister Nivedita, and many personalities of the early 20th century. The walls of the Bose Institute, which he founded were hung with old masters and decorated with valuable frescos.

When he retired from Presidency College, for two years, Bose dedicated himself to building for India what he had always considered crucial for scientific progress - a well-endowed facility for research in the sciences. In 1917, J C Bose founded the Bose Institute, in Kolkata, with the purpose of investigating fully, as he recorded, "the many and ever opening problems of the nascent science which includes both life and non-life". Bose was the Director of this institute up to 1937, when he died. The Institute is now one of the leading establishments in India and is marked by the variety of fields where work is done. It has departments in Physics, Chemistry, Botany, Microbiology, Biochemistry and Biophysics, Molecular Cellular Genetics, Animal Physiology, Environmental Sciences, Immunotechnology. In 1988, a Bioinformatics Centre was added, with work on Genetic Engineering, Biocrystallography, Biocomputing and Molecular Modeling.