Three great scientists I encountered

It is the purpose of this essay to describe about my direct experiences with three great scientists C V Raman, S Chandrasekhar and Homi Bhabha
through some interesting events.

C V Raman

The year may be 1955 or 1956. It was announced that C V Raman was going to give a lecture at the Presidency College, Madras. At that time I was a BSc (Hons) student at the Madras Christian College. Our Professor MA Thangaraj asked us all to go and attend Raman's lecture. I think he too went.

Students and professors were listening to Raman's lecture very attentively. Raman talked about his own theory of the specific heat of solids.

Einstein had solved an important puzzle about the specific heats of solids using quantum theory. After that Peter Debye gave a more detailed theory. Einstein had assumed that the atoms or molecules of a solid had one frequency of vibration. In reality, the atoms will have many frequencies. Debye generalized Einstein's theory by assuming that the solid has all frequencies up to a maximum.

Raman did not agree with Debye's theory. Every solid will have certain specific frequencies of vibration depending on its crystal structure. Raman believed that the specific heat must be calculated using only these frequencies. This was called Raman's theory of specific heats.

Raman talked about this theory only. His lecture was wonderful. He fascinated all of us by his explanation of his theory using well-chosen firm words in his ringing voice. He compared his theory with Debye's theory and established the superiority of his theory. His voice rose. "Debye's theory is not worth the paper on which it is written", so saying, he threw the bundle of papers in his hand. The papers flew over our heads and fell into the waste basket in the corner!

It seemed as if an electric shock passed through everybody. All the students received a totally new experience. None of us had heard such a lecture up to that time. All of us felt that this is the way lectures must be delivered. For many days after that, Raman's words were ringing in our ears which had become bored by listening to uninteresting lectures.

Chandrasekhar

Let us now come to the years 1961-63. I was doing my Ph D in Chicago University. Chandrasekhar, who was a Professor there, had already attained great fame. One day from a distance I saw Chandrasekhar emerging from the office of the physics department and I felt that I was lucky to have come to Chicago University.

I learnt that Chandrasekhar was going to give two courses of lectures and I immediately registered in both. General Theory of Relativity (created by Einstein in (1915) and Mathematical Physics were those two courses. For almost a whole year, I listened to these courses and learnt them.

Chandrasekhar lived in Williams Bay, about 60 km north of Chicago. He was working in the Yerkes Observatory there, apart from being a Professor at Chicago. He used to commute between Chicago and Williams Bay. This happened even in the midwinter in freezing cold weather. There is a very interesting fact connected to this, which happened some 10 years before my time in Chicago. Chandrasekhar commuted like this, just to teach two students in Chicago University. Sometime after that, some people asked Chandrasekhar why he worked so hard just for a class of two students. His reply: "My whole class got Nobel Prize later." Those two are TD Lee and CN Yang who got Nobel Prize in 1956.

Nobody in our class got Nobel Prize. But his lectures were so good that they were imprinted into my mind very firmly. I must mention an interesting event however. One day during a lecture, he was writing on the blackboard. An American student interrupted him and referring to an equation on the blackboard said that the negative sign should be changed to a positive sign. Chandrasekhar agreed and changed the sign.
After a few seconds, the same student said that the old sign was correct. Chandrasekhar thought for a few seconds and agreeing to this also, changed the sign again!

Chandrasekhar was considered the greatest mathematical physicist after Lord Raleigh. Even such a great man can make mistakes!

An important point about the subjects that he taught us. Before starting his lectures on General Relativity, he said that he was teaching it, so that he can learn it himself. Before starting his lectures on mathematical physics, he said he is teaching us generalized functions since he wanted to use them on his research on Black Holes. Up to that time his research did not involve General Relativity or Black Holes. Only after the lectures
to us, his famous research on Black Holes came. He said "Black Holes are the most perfect objects in the Universe".

Although I was listening to his lectures for one whole year, I do not remember to have spoken to him. In the physics department of Chicago University, there were many Indian students. He did not have any contact with any of them. The reason was his natural shyness.

So imagine our surprise when three of us (R Ramachandran who was a student like me, A P Balachandran who had already got his Ph D in Madras and was a post-doc at Chicago and myself) got an invitation for lunch at his home!

He specified all the details of the train from Chicago in the letter of invitation. He was waiting for us at Williams Bay station and took us to his home in his car. We stayed there for one whole day. He took us to the Yerkes Observatory, showed us the big telescope there and explained its details.

Mrs Lalitha Chandrasekhar cooked delicious South Indian food and served us. After that Chandrasekhar took a little rest while we three played some ball game in his garden. When we went inside, tea and snacks were ready. Chandrasekhar and Lalitha joined us. On that day, there was an important event being broadcast in the TV. Edward Teller, the father of the Hydrogen Bomb, was giving testimony, in front of the Senate Committee. During the testimony, at one point, Teller became so emotional that tears appeared in his eyes! Chandrasekhar talked to us about Tellerand many other scientists.

After that the conversation shifted to other matters. We discussed Indian politics and about Science in India. We could feel how much interested Chandrasekhar was about India. We three were doing research in elementary particle physics. We tried to answer his many questions about this subject and also got to know his views.

We returned to Chicago at night with a feeling of satisfaction that we spent a whole day with a great man.

Later when I was working at Tata Institute of Fundamental Research, Bombay and Institute of Mathematical Sciences, Madras I met Chandrasekhar many times and listened to his lectures.

In the year 1987, the centenary of Srinivasa Ramanujan was celebrated in Madras. Our Institute of Mathematical Sciences along with a few other institutions organized that event. Prime Minister Rajeev Gandhi inaugurated it. Chandrasekhar and many other scientists lectured. The first lecture was by Chandrasekhar and we were eagerly waiting for it. Although no title for his lecture had been announced, since it was in celebration
of Ramanujan, Chandrasekhar was expected to lecture on Ramanujan. The first sentence he uttered: "Ramanujan was certainly a great man, but Newton was a greater man. So I will talk about Newton".

If it had been anybody else, there would have been some opposition. But he got away with it. And the lecture was a great success.

The topic he took up was Newton's famous Principia. He took each of Newton's theorems one by one and gave his own proof for them. Then he compared Newton's original proof with them. He showed how Newton's original proofs were more elegant, although in these 300 years
after Newton, mathematics and physics have made enormous progress and we are at an advantage to use them in the proofs. Later Chandrasekhar's book containing this came out. This was his last book. But we heard all of that from his mouth on that day.

Homi Jahangir Bhabha

Homi Jahangir Bhabha was not only a great scientist but also the architect who laid the foundation for India's growth of science and technology. Tata Institute of Fundamental Research and Bhabha Atomic Research Centre are his creations.

The scientists in the Indian Universities and other science institutions must continue to work there and develop them further. Therefore the scientists and engineers needed for the department of atomic energy must be created by the department itself. This was the motivation for Bhabha's establishing the atomic energy training school in 1957. The scientists and engineers in the department of atomic energy and its other institutions were recruited mostly through the training school. The training school is one of the main reasons for the rapid growth of the department.

I was one of the first batch trainees of the school. On the first day of the school Bhabha gave an inspiring lecture to us. He talked about the future of India and his dream and plans to bring nuclear energy to India. At the end of his lecture during the question time, one of us was bold enough to ask: " At the end of our training period, what kind of job will you give us?". This question gave a little shock to all of us.

But Bhabha answered it without any hesitation:" If you prove yourself, you will get my job, the chief of the atomic energy department". He was not bluffing. Dr Anil Kakodkar who became the chief in the year 2001 was the sixth batch trainee!

After I joined Tata Institute of Fundamental Research in 1958, I could see Bhabha many times. But since his full attention was concentrated on managing the atomic energy department and creating nuclear reactors, he could not devote any time on his basic research. So there was no direct connection between him and research scholars like me. But he never failed to attend the Wednesday Colloquia,(if he was in town). Further, we could see him whenever important scientists came and lectured. All of us eagerly looked forward to the Wednesday Colloquia and the Special Lectures.

In the year 1961 TIFR conducted a Summer School in elementary particle physics. It went on for three weeks in the Indian Institute of Science, Bangalore. Two famous scientists Murray Gell-Mann and Richard Dalitz lectured on the discoveries in elementary particle physics. I have described an important event (connected to the discovery of quarks) that took place in this summer school in another essay.

This summer school was organized by the initiative of Bhabha. Although many years had elapsed since he left elementary particle research, he listened to all the lectures of Gell-Mann and Dalitz and was involved in discussions with him. Our participation in all this was a good experience for all of us.

After that we were all taken to the Kolar Gold mines and shown the cosmic ray research there started by the initiative of Bhabha. In 1965, that research became famous through the first detection of cosmic-ray-produced neutrinos.