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JC Bose a Hindu pioneer of radio waves
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Jagadish Chandra (J.C) Bose was a pioneer in the investigation of radio and microwave optics and the article details his experiments and research works. His contribution in the field of plant physiology was discussed in the last article.
It was believed that British physicist James Clerk Maxwell predicted mathematically the existence of electromagnetic waves of diverse wavelengths, but he died in 1879 before his predictions were experimentally verified. British physicists Oliver Lodge demonstrated the existence of Maxwell’s waves in 1887-88 and German physicist Heinrich Hertz showed experimentally the existence of electromagnetic waves in free space in the year 1888. Lodge pursued Hertz work after his death and published a book based on Hertz work. The book caught Bose’s attention in India while he was working in Presidency College, India.
Bose followed up the microwave research, in which he reduced the waves to the millimeter level (about 5 mm wavelength) since he realized the disadvantages of long waves for studying their light-like properties. In November 1894, in a public demonstration in Kolkata (India) Bose ignited gunpowder and a rang a bell at a distance using millimeter range wavelength microwaves. His demonstration was witnessed by Lieutenant Governor Sir William Mackenzie. Bose concluded from his demonstration that since invisible light can easily pass through brick walls and buildings, hence messages can be transmitted by means of it without the mediation of waves. Similar experiments were performed by Popov in Russia who also hoped in his journal that distant signaling is possible with radio waves.
In May 1897, Marconi conducted his wireless signaling experiment on Salisbury Plain. It appeared that Bose’s demonstration of remote wireless signaling had a priority over Marconi as he was the first to use a semiconductor junction to detect radio waves and he also invented various now commonplace microwave components. In 1954, Pearson and Brattain gave priority to Bose for the use of semiconducting crystal as a radio waves detector and since the research work at millimeter wavelengths were almost non existence for nearly 50 years.
In his demonstration Bose had used wave guides, horn antennas, dielectric lenses, various polarizer and even semiconductors at frequencies as high as 60 Hertz. In fact Neville Francis Mott a Nobel Laureate in 1977 in the field of solid state electronics remarked that JC Bose was at least 60 years ahead of his time. But Bose was never in the favor of patenting and suggested others to use his research work, however due to his peer pressure he did file for a patent for one of his inventions. In 1897, Bose reported on his microwave experiments in Royal Institution in London where he speculated the existence of electromagnetic radiation from the sun and suggested that either the solar or terrestrial atmosphere might be responsible for the lack of success in detecting such radiation.
Bose was from a poor Hindu family but his interest in the fields of radio and microwaves enabled him to survive thorough various odds. During Bose’s time India was under British colonial rule and the British Government was not conducive to research attempts. Hence Bose spent his hard earned money for making experimental equipments. Bose’s contribution in the remote wireless signaling was commendable as he was the first to use a semiconductor junction to detect radio waves but he is rarely given the deserved recognition in India and abroad. Most of his equipments are now commonplace microwave components and Bose was much ahead of his time.
For more info http://www.tuc.nrao.edu/~demerson/bose/bose.html
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