Professor NB Chakrabarti (NBC) taught me electromagnetic theory during my college days at the Institute of Radiophysics and Electronics (INRAPHEL), Calcutta University. He was then already acclaimed for his research contribution in the area of communication engineering. NBC used to believe that all the students attending his class in electromagnetic theory had already known the subject and read “Stratton”. For a mediocre student like me, it was somewhat difficult to follow both NBC and Stratton. My classmates Samir (S.K. Lahiri, an internationally acclaimed scientist in the area of solid state physics and microelectronics) and Pradip (P.K. Saha, an internationally acclaimed scientist in the area of microwave engineering) helped me to follow the lectures of NBC.
Once NBC asked Rakesh da (Professor Rakesh Ganguli, who was a very popular and good teacher) of IIT-Kharagpur to take the audio recordings of the lectures of a short-term course, which NBC was conducting as its convener. I was attending the course as a student participant. Rakesh da, who was very popular for his jokes, told that he would take the recordings of the lectures of all the resource persons of the course except those delivered by NBC since none of the participants would follow them. Rakesh da jokingly told that he would not like to keep an evidence of NBC’s bad teaching. At this, NBC asked me to know if he was a bad teacher in the class. Rakesh da again jokingly told that I would disclose the truth provided NBC immediately gave me the permission to submit my PhD thesis without adding to it any further work.
The teaching of NBC in the area of electromagnetic theory had a spell to create in me an interest in the subject that motivated me to do my research in the area of applied electromagnetics. I dedicated one of the books authored by me in the subject to our ‘Sir’ NBC with a foreword written by Suhas da (Professor S.C. Dutta Roy, the world famous digital signal processing man)¾a great admirer of NBC to whom NBC was Nirmal da). After obtaining my M. Tech degree I joined INRAPHEL as a PhD research scholar in the area of radio astronomy under the mentorship of Professor Mrinal Kanti Das Gupta (MKDG). However, shortly I left INRAPHEL to join DRDO-DLRL and then left DRDO-DLRL to join IIT-Kharagpur as a PhD research scholar under the tutelage of NBC. Interestingly, you can shuffle the letters of ‘Mrinal’ to get ‘Nirmal’, the first names of MKDG and NBC being Mrinal and Nirmal, respectively. Thus, I discovered the anagrams in the names of my two mentors.
I was taught by NBC to think ab initio. I remember he taught me as to how to solve a differential equation in my investigation into harmonic generation and intermodulation distortion in a vacuum electron device. Samir seeing my approach told me that NBC taught me how one can solve a differential equation by using Laplace transform. In fact, NBC did not ask me to go through a text book and learn ‘mathematics’ that would have perhaps scared a student like me who was weak in mathematics, showing how much kind-hearted he was with his students!
It is well known that NBC loves his doctoral student Apurba Kumar Dutta (AKD), who later on became Professor at INRAPHEL. On one Sunday (holiday) AKD was supposed to carry out some experiments at E & ECE Department while he was in IIT-Kharagpur. Finding AKD absent in the Department on the day, NBC went to his hostel to find AKD playing a game of cards with his friends. NBC immediately replaced AKD in the game and asked him to rush to the Department to complete his work. That was his spirit to motivate his students.
In a different incident, on one Sunday NBC could not find me in the Department (E & ECE) at IIT-Kharagpur. Someone gave him the hint that an M. Tech student Hari Mohan Gupta (HMG) knew where I had been. In fact, without letting NBC know I went to my home at Jamshedpur around 150 km off from Kharagpur. We had a pet dog, which was so big that none of the not-very-strong lady members of our family were able to ‘tackle’ it. My brother, who was then the only male member who could tackle the dog, had to leave Jamshedpur for Kolkata for a day to appear for an interview for a job. So, I went home at Jamshedpur, unfortunately without informing NBC. Under ‘pressure’ HMG told him that I went to Jamshedpur. NBC became angry that I did not get importance to my research and preferred to attend a dog. In fact, he became so disappointed that he stopped talking with me. We used to communicate with each other through either Samir or our ‘Boudi’ (elder brother’s wife in Bengali), NBC’s wife, for a long period. At that point of time I had to leave IIT-Kharagpur to take a teaching job at RIT (now NIT)-Jamshedpur without writing my doctoral thesis. I used to visit IIT-Kharagpur quite often then from Jamshedpur for consulting the library of the Institute. Seeing me there in E & ECE Department of the Institute NBC would know from Samir if I had informed Boudi of my visit so that Boudi could arrange my launch. While remaining in this ‘non-talking’ term with me for a long time, he left for Loughborough, UK to take up a visiting assignment. However, I published a couple of papers in a journal in his absence from the country to make him pardon me and come out of those ‘non-talking’ terms after his return from UK. Soon after his return to the country, he, along with Boudi and their two daughters Shampa and Pampa, visited our home at Jamshedpur, and we all went to BIT-Meshra and stayed with Siya Ram (Sharma), Sir’s student who was a lecturer at BIT-Meshra, in his home there for sightseeing around Ranchi; my wife Moni and my elder son Bilku also accompanied us.
In one of my visits to IIT-Delhi, HMG (whom I already mentioned above), who was then Professor at IIT-Delhi, claimed that NBC loved him more than he did me. The reason he gave was that he was the only student who is the recipient of a physical slap from NBC for initially not disclosing that I went home to take care of a pet dog at the cost of my research work. He said that it was because of NBC’s affectionate teaching and that ‘slap’ he became a teacher par excellence in the area of communication engineering.
Boudi took me to an astrologer (Mr. Amaresh Bhattacharya) to know my fate without the knowledge of Sir. She was worried that my completing the thesis work had been getting delayed due to my illness.
Once Samir sent me an SOS to immediately rush to Kharagpur from my home at Jamshedpur. NBC had a technical question which he thinks Samir, who was an area expert related to the question, would not be able to answer. Sir said that I would get up in one early morning and get the answer without bothering that I was not an area expert as Samir was. At the suggestion of Samir, I went to Kharagpur from Jamshedpur and listened to Sir’s question. Obviously, as Samir had predicted, I could not make out a fig the Sir’s question. However, thereafter NBC forgot the question and did not ask Samir nor me anymore that question.
Sir was unhappy that I authored a book on technical writing. He asked me to focus on my research and not spend my time in writing books like “How to fly a kite”.
I thought I would work in the area of communication engineering for my doctoral research under the tutelage of NBC. However, NBC saw in my hand the book ‘Plasma Physics’ by S. Chandrasekhar when I had met him at IIT-Kharagpur to probe into the possibility of doing research there with him. So, NBC allotted me the area of my doctoral research: ‘nonlinear effects in double-beam and beam-plasma amplifiers’, which was different from the area of communication engineering which I thought I would work a degree for. Being a genius it was possible for NBC to mentor his students in diverse areas. In fact, that is how being a D. Sc in communication engineering he established with the all-out assistance and leading role played by Samir, the ‘Microelectronics Centre’ at IIT-Kharagpur. It reminds us that JC Bose (JCB) was a physicist, microwave engineer, and botanist, all in a single person. Thus, seeing the work of the great scientists like JCB and NBC, I recall William Cecil Dampier: “There is only one nature – the division into science and engineering is a human imposition, not a natural one. Indeed, the division is a human failure; it reflects our limited capacity to comprehend the whole.”