Archarya Sir Jagadish Chandra Bose is one of the leading luminaries of Indian Science.
Incidences from the life of this extrememly talented individual highlight his exemplary value system, his humility and his grit and determination. For example, when he was faced with discrimation he declined his salary and continued to work for 3 years, his research conducted in trying circumstances with meagre resources, or his disinclination of filing patents for his inventions.
However in this small article we only aim to highlight 2 of his inspiring efforts.
Radio research and wireless signalling – including use of semi-conductor
Sir Bose’s research in microwave waves allowed him to generate waves in the millimetre level (about 5 mm wavelength).
The first remarkable aspect of Bose’s follow up microwave research was that he reduced the waves to the millimetre level (about 5 mm wavelength). He realised the disadvantages of long waves for studying their light-like properties.
During a demonstration at Town Hall of Kolkata in the 1890s, Bose ignited gunpowder and rang a bell at a distance using millimetre range wavelength microwaves.
He used waveguides, horn antennas, dielectric lenses, various polarisers and even semiconductors at frequencies as high as 60 GHz. Which is quite mind-boggling, given the time and circumstances.
A diagram of microwave spectrometer apparatus built by Indian scientist Jagadish Chandra Bose in his pioneering experiments with microwaves from his 1897 paper is available here: http://en.wikipedia.org/wiki/File:Jagadish_Chandra_Bose_microwave_apparatus.png
He wrote – “The invisible light can easily pass through brick walls, buildings etc. Therefore, messages can be transmitted by means of it without the mediation of wires.”
Sir J.C.Bose was thus also a pioneer in the use of semiconductors.
Point-contact microwave detector rectifiers made of lead sulfide were used by Jagadish Chandra Bose in 1904; the cat’s-whisker detector using natural galena or other materials became a common device in the development of radio.
IEEE (Institute of Electrical and Electronics Engineers) named him one of the fathers of radio science. And his experimental work in millimetre-band radio was recognised as an IEEE Milestone in Electrical and Computer Engineering, the first such recognition of a discovery in India.
Work with Plants
Sir J.C.Bose was a self confessed nature lover. I dont know since when plants have been regarded as living beings – but it seems that during Sir Bose’s time they were not regarded as living. Sir Bose invented the crescograph. A very marvellous, delicate, precisely calibrated instrument to measure plant responses to various stimuli.
Stimuli that Sir Bose experimented with included temperature, chemicals, gases and electricity.
The crescograph used clockwork gears to magnify the movements of plants upto 10000 times on a glass screen. Thus he was able to record life-like responses (attributed to animals) in plants as well. For example, quivering by the plant when in distress / injured.
Sir Bose recorded his findings in numerous publications:
Response in the Living and Non-living, 1902
Plant response as a means of physiological investigation, 1906
Comparative Electro-physiology: A Physico-physiological Study, 1907
Researches on Irritability of Plants, 1913
Physiology of the Ascent of Sap, 1923
The physiology of photosynthesis, 1924
The Nervous Mechanisms of Plants, 1926
Plant Autographs and Their Revelations, 1927
Growth and tropic movements of plants, 1928
Motor mechanism of plants, 1928
Several of these can still be purchased online.
Wikipedia pages for Jagadish Chandra Bose, Crescograph, Semiconductor
Bose Institute Kolkata
Plant response as a means of physiological investigation, 1906 (Book)