Wednesday, January 21, 2015

Jagdish Chandra Bose -Unsung Hero of Radio wave

wpe2.jpg (15535 bytes)Achievements of Sir J. C. Bose in the field of communication
(In a Nutshell)
  • Sir J. C. Bose invented the Mercury Coherer (together with the telephone receiver) used by Guglielmo Marconi to receive the radio signal in his first transatlantic radio communication over a distance of 2000 miles from Poldhu, UK to Newfoundland, St. Johns in December 1901. Guglielmo Marconi was celebrated worldwide for this achievement, but the fact that the receiver was invented by Bose was totally concealed. Read Bose's original paper on the receiver device.
  • In 1895, Sir J. C. Bose gave his first public demonstration of electromagnetic waves, using them to ring a bell remotely and to explode some gunpowder. He sent an electromagnetic wave across 75 feet passing through walls and body of the Chairman, Lieutenant Governor of Bengal. (I am in process of ascertaining how this experiment is placed in context of works by other scientists towards demonstrating remote transmission of EM waves).
  • Sir J. C. Bose holds the first patent worldwide to invent a solid-state diode detector to detect EM waves. The detector was built using a galena crystal. Have a look at Bose's patent and wait for an interesting article on the same soon.
  • Sir J. C. Bose was a pioneer in the field of microwave devices. His contribution remains distinguished in the field and was acknowledged by the likes of Lord Kelvin, Lord Rayleigh, etc. Read what people thought about J. C. Bose. Refer to [1,2] to study the work of J. C. Bose in the field of microwave.

Jagadish Chandra Bose: The Real Inventor of Marconi's Wireless Receiver
In the year 1998, Dr. Probir K. Bondyopadhyay found out that it was actually Sir J. C. Bose who invented Marconi's Italian Navy Autocoherer. He explained the sequence of events in great detail in his paper, "Sir J. C. Bose's Diode Detector Received Marconi's First Transatlantic Wireless Signal Of December 1901 (The "Italian Navy Coherer" Scandal Revisited)." [ 3, Proc. IEEE, Vol. 86, No. 1, January 1998.]

Read a complete article covering the technical details of Marconi's experiment, the receiving device (coherer) and the chronology of events that took place when the first transatlantic wave was successfully transmitted. The article clearly proves that Sir J. C. Bose was the inventor of the Mercury Autocoherer.

The article goes into technical details and background to enable a person with no knowledge of history of radio communication to understand the contribution of Sir J. C. Bose clearly. You will definitely enjoy the concepts and devices used at a time when modulation was not known and diode had not been invented!

A short version of the complete article now published in Ancient Wireless Association Journal is available here.
(Citation: V. Aggarwal, "Jagadish Chandra Bose: The Real Inventor of Marconi’s Wireless Detector", The Ancient Wireless Association Journal, July 2006, Vol. 47/#3, pp. 50-54)
popoff2.gif (20467 bytes)Experiments with a Replica of the Bose Detector- K. L. Groenhaug

The autocoherer invented by Bose was nearly a solid state diode, which was actually invented some 50 years after the autocoherer was invented. Groenhaug built a replica of a Bose detector and compared its characteristics with that of a diode. Have a look at this interesting paper. Groenhaug also plans to study the performance of Bose's galena detector and I eagerly wait for the results of his study.
Did Popov invent radio: It is so claimed and believed by some, that Popov, a Russian scientist was the first to transmit information over wireless. Where does he fit in the history of radio communication?
1. Darrel T. Emerson, “The Work of Jagadis Chandra Bose: 100 Years of Millimeter-Wave Research,” IEEE Transactions on Microwave Theory and Techniques, Vol. 45, No. 12, pp. 2267-2273, Dec. 1997
2. T. K. Sarkar, D. L. Sengupta, “An Appreciation of J. C. Bose’s Pioneering Work in Millimeter Wave”, IEEE Antenna and Propagation Magazine, Vol. 39, No. 5, Oct. 1997
3. Probir K. Bondyopadhyay, "Sir J. C. Bose's Diode Detector Received Marconi's First Transatlantic Wireless Signal Of December 1901 (The "Italian Navy Coherer" Scandal Revisited)," Proc. IEEE, Vol. 86, No. 1, January 1998

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