Showing posts with label JC BOSE. Show all posts
Showing posts with label JC BOSE. Show all posts

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

Monday, July 14, 2014


मारकोनी के आविष्कार के कई वर्ष पूर्व 1855 में आचार्य जगदीशचन्द्र बसु बंगाल के अंग्रेज गवर्नर के सामने अपने आविष्कार का प्रदर्शन कर चुके थे।उन्होंने विद्युत तरंगों से दूसरे कमरे मे घंटी बजाई और बोझ उठवाया और विस्फोट करवाया। आचार्य बसु ने अपने उपकरणों से 5 मिलीली.की तरंग पैदा की जो अब तक मानी गई तरंगों में सबसे छोटी थी। इस प्रकार बेतार के तारों के प्रथम आविश्कारक आचार्य बसु ही थे। बसु ने अपने उपरोक्त आविश्कारों का इंग्लैंड में भी प्रदर्शन किया।इन प्रदर्शनों से अनेक तत्कालीन वैज्ञानिक आष्चर्यचकित हो गये। उपरोक्त प्रयोगों को आधार बनाकर जब नये प्रयोग उन्होंने प्रारम्भ किये तो वे इस निश्कषर् पर पहुंचे कि सभी पदार्थों में जीवन प्रवाहित हो रहा है। अपने प्रयोग…ों द्वारा उन्होंने यह सिध्द कर दिया कि पेड़ पौधों में भी जीवन का स्पंदन है।.
और वनस्पतियों पर शोध करते समय उन्होंने एक ऐसे यंत्र का निर्माण किया जिससे सूक्ष्म तरंगों के प्रवाह से पानी गरम हो गया यह प्रयोग आगे बढाने के लिए धन के आभाव ने इस प्रयोग को वहीं रोक दिया परन्तु कृपया एक बार पुन्ह ध्यान दें कि पानी कैसे गर्म हुआ और फिर सोचें माइक्रोवेव क्या करता है.
लेकिन आचार्य बसु का ध्यान पेटेंट करवाने में समय व्यर्थ ना करने के स्थान पर विज्ञानं की अधिक से अधिक सेवा में था इसका फायदा उठाकर इन पश्च्यात जगत के तकनीकज्ञों ने कलपुर्जे जोड़कर रेडियो और माइक्रोवेव का नाम देकर पेटेंट करवा दिया और खुद को वैज्ञानिक के रूप में विश्व के सामने प्रेषित किया.