Homi Jehangir Bhabha

"I know quite clearly what I want out of my life. Life and my emotions are the only things
I am conscious of. I love the consciousness of life and I want as much of it as I can get.
But the span of one's life is limited. What comes after death no one knows. Nor do I care. Since, therefore,
I cannot increase the content of life by increasing its duration, I will increase it by increasing its intensity.
Art, music, poetry and everything else that consciousness I do have this one purpose - increasing the
intensity of my consciousness of life".

H.J. Bhabha

Homi Jehangir Bhabha is mostly known as the chief architect of India's nuclear programme. However, his contribution to India's development goes far beyond the sphere of atomic energy. He had established two great research institutions namely the Tata Institute of Fundamental Research (TIFR), and the Atomic Energy Establishment at Trombay (which after Bhabha's death was renamed as the Bhabha Atomic Research Centre (BARC). He played a crucial role in the development of electronics in India. Bhabha was an outstanding scientist and a brilliant engineer. He derived a correct expression for the probability of scattering positrons by electrons, a process now known as Bhabha scattering. His classic paper, jointly with W. Heitler, published in 1937 described how primary cosmic rays from space interact with the upper atmosphere to produce particles observed at the ground level. Bhabha and Heitler explained the cosmic ray shower formation by the cascade production of gamma rays and positive and negative electron pairs. 'In 1938 Bhabha was the first to conclude that observations of the properties of such particles would lead to the straightforward experimental verification of Albert Einstein's theory of relativity'. Bhabha possessed sensitive and trained artistic gifts of the highest order. The environment in which he grew certainly helped him to develop all these fine qualities. He loved music and dancing. He had considerable knowledge of both Indian and western music. He painted and sketched. He designed the settings of dramatic productions. He was an architect of no mean ability. Bhabha was a perfectionist. He was a true lover of trees and did everything under his powers to protect them. In his tribute paid to Bhabha Lord Redcliffe-Maud has aptly described the different facets of Bhabha's personality: "Affectionate and sensitive, elegant and humorous, dynamic and now dead. Homi was one of the very few people I have ever known (Maynard Keynes was another) who enhance life whatever the context of their living. In Homi's case this was because he was fantastically talented but so fastidious about standards that he was never a dilettante. Whatever he set himself to do, he did as a professional- but one who worked for love. He was relentlessly creative, enhancing life because he loved all forms of it. So he became a living proof that scientific excellence can go with excellence in arts and racial differences need be no bar to friendship. When Indian Art was last exhibited in London, the one picture chosen for reproduction on the poster outside Burlington House was one of Homi's. He was as fond of music as he was of pictures, contriving to fly in from India as the first Edinburgh Festival began and, when the question of a late Beethoven quartet was raised in conversation, knowing the opus number. At one UNESCO conference after another he stood out even among the other distinguished members of the Indian delegation, as a world citizen qualified in all three subjects - education, science and culture - as hardly another member of the conference was. He was in fact an obvious choice for the headship of the Organization if he had felt inclined that way. Those qualified must judge how grievous was his death for India and for science and for civilization".

Homi Jehangir Bhabha was born on 30 October 1909 in a wealthy Parsi family of Bombay (recently renamed as Mumbai). Bhabha's family had a long tradition of learning and service in the field of education. His grandfather, also named as Homi Jehangir Bhabha, was the Inspector General of Education in the State of Mysore. Bhabha's father Jehangir Hormusji Bhabha was educated at Oxford and later qualified as a lawyer. His mother Meheren was grand-daughter of Sir Dinshaw Maneckji Petit, widely respected in Bombay for his philanthropic endowments. Hormusji's sister that is Bhabha's paternal aunt Meherbai married Sir Dorab J. Tata (1859-1932) the eldest son of Jamshetji Nusserwanji Tata (1839-1904).

Bhabha attended the Cathedral and John Connon Schools in Bombay. After passing Senior Cambridge Examination at the age of 15 Bhabha entered the Elphinstone College in Bombay and later the Royal Institute of Science, also in Bombay. In 1927 Bhabha joined the Gonville and Caius College in Cambridge, the same college where his uncle Sir Dorab J. Tata had studied and who made a donation of twenty-five thousand pounds to the college in 1920. He took the Mechanical Sciences Tripos in 1930. It may be noted here that both his father and his uncle Sir Dorab J. Tata wanted Bhabha to become an engineer with the view that ultimately he would join the Tata Iron and Steel Company at Jamshedpur. At Cambridge Bhabha's interests gradually shifted to theoretical physics. In 1928 Bhabha in a letter to his father wrote: "I seriously say to you that business or job as an engineer is not the thing for me. It is totally foreign to my nature and radically opposed to my temperament and opinions. Physics is my line. I know I shall do great things here. For, each man can do best and excel in only that thing of which he is passionately fond, in which he believes, as I do, that he has the ability to do it, that he is in fact born and destined to do it... I am burning with a desire to do physics. I will and must do it sometime. It is my only ambition. I have no desire to be a `successful' man or the head of a big firm. There are intelligent people who like that and let them do it... It is no use saying to Beethoven `You must be a scientist for it is great thing ' when he did not care two hoots for science; or to Socrates `Be an engineer; it is work of intelligent man'. It is not in the nature of things. I therefore earnestly implore you to let me do physics." For doing physics he wanted to do the Mathematics Tripos. Bhabha's father had to yield to his son's firm determination. But he put a condition. He told Homi that in case he could complete the Mechanical Tripos successfully he would allow him to stay in Cambridge to take up the Mathematics Tripos. So when Bhabha passed the Mechanical Tripos with first class his father allowed his son to fulfill his wishes. Thus two years later Bhabha passed the Mathematics Tripos again with first class. Bhabha was taught by Paul Adrien Maurice Dirac (1902-84), who was Lucasian Professor of Mathematics (1932-69) at Cambridge and awarded the Nobel Prize in Physics in 1933 with Erwin Schrodinger (1887-1961) for their work in quantum theory. Bhabha joined the Cavendish Laboratory, from where he obtained his Ph.D. in theoretical physics. During 1932 to 1934 he held the Rouse Ball Traveling Studentship in mathematics. He also held Salomons Studentship in Engineering during 1931-1932. He traveled in Europe and worked with Wolfgang Pauli (1900-58) in Zurich and Enrico Fermi (1901-54) in Rome. His first research paper published in 1933 won him the Isaac Newton Studentship in 1934, which he held for three years and mostly worked in Cambridge except for a short period when he worked with Niels Henrik David Bohr (1885-1962) at Copenhagen. When Bhabha was at Cavendish Laboratory many sensational discoveries were made. In 1932 James Chadwick (1891-1974) demonstrated the existence of the neutron, John Douglas Cockroft (1897-1967) and Ernest Thomas Sinton Walton (1903-95) produced the transmutation or artificial disintegration of light elements by bombarding high speed protons and Patrick Maynard Stuart Blackett (1897-1974) and Giuseppe Paolo Stanislao Occhialini (1907-) demonstrated by cloud-chamber photographs the production of electron pairs and showers by Gamma radiations.

At Cambridge Bhabha's work centered around cosmic rays. It may be noted here that the existence of penetrating radiations coming from outer space was detected towards the close of the 19th century by Charles Thomson Rees Wilson (1869-1959) in simple experiments on electroscopes. Robert Andrews Millikan (1868-1963), the US physicist and Nobel Prize winner, gave the name of cosmic rays to these radiations consisting of highly energetic charged particles. The radiations reaching the top of the atmosphere from outer space are referred, to as primary cosmic rays. They consist of various types of nuclei but prominently of protons. Primary cosmic rays produced secondaries by interaction with the atmosphere.

As mentioned earlier Bhabha jointly with W.Heitler explained the cosmic-ray shower formation in a paper published in 1937. Before this the mechanism responsible for shower formation was the subject of much speculation.

The important contributions made by Bhabha while working at Cambridge have been summarised by G. Venkataraman (in his book, Bhabha and His Magnificent Obsessions, Universities Press, Hyderabad, 1994) as :

The explanation of relativistic exchange scattering (Bhabha Scattering).

• The theory of production of electron and positron showers in cosmic rays (Bhabha-Heitler theory).
• Speculation about the Yukawa particle related to which was his suggestion of the name meson.
• Prediction of relativistic time dilatation effects in the decay of the meson.

About the importance of Bhabha's research work Cecil Frank Powell (1903-1969) who was awarded the 1950 Nobel Prize for physics wrote: "Homi Bhabha made decisive contributions to our understanding of how they (the showers) developed in terms of electromagnetic processes. He was also well-known at this time for his attempts to account for those elementary particles then known to exist by a method using group theory. He was thus a very early exponent of those methods used many years later for a similar purpose by Gell-Mann and others. My friend, Leopold Infeld says that he was a distinguished and elegant theorist and his papers were always written in the best of taste".

It was Bhabha who suggested the name 'meson' now used for a class of elementary particles. When Carl David Anderson (1905-91) discovered a new particle in the cosmic radiation with a mass between that of electron and the proton he named it 'mesoton' which was subsequently changed by him to mesotron presumably at the advice of Millikan. Bhabha in a short note to Nature (February 1939) proposed the name 'meson'. In this note he wrote: "The name 'mesotron' has been suggested by Anderson and Neddermeyer for the new particle found in cosmic radiation with a mass intermediate between that of the electron and the proton. It is felt that the 'tr' in this word is redundant, since it does not belong to the Greek root 'meso' for middle; the 'tr' in neutron and electron belong, of course, to the roots "neutr" and "electra".... It would therefore be more logical and also shorter to call the new particle a meson instead of a mesotron." Anderson's particle (mu-meson) was first thought to be the particle predicted by Hideki Yukawa (1907-81) that was thought to carry the strong nuclear force and hold the nucleus together. However, later when it was found that its interaction with nucleons was so infrequent it became doubtful whether it could perform the role described by Yukawa, that is to act as nuclear 'glue'. This was finally resolved when in 1947 C.F. Powell discovered a particle again in cosmic radiation with a mass of 264 times that of the electron (pi-meson or pion). Pion interacted very strongly with nucleons and thus filled precisely Yukawa's predicted role. Mu-meson or muon is the decay product of pi-meson.

In 1939 when the Second World War broke out, Bhabha was in India. He came for a short holiday. However, the war changed his plan. Most of the scientists in England had to take part in war activities and there was no scope for doing basic research. So Bhabha had to abandon his plan to return to England to resume his research work at Cambridge. It may be recalled here that Prasanta Chandra Mahalanobis (1893-1972) who after completing the Physics Tripos made arrangement to work under C.T.R. Wilson, the inventor of the cloud chamber, at the Cavendish Laboratory came back to India for a short vacation. He also could not go back because the First World War broke out. In 1940 Bhabha joined the Indian Institute of Science at Bangalore where a Readership in Theoretical Physics was specially created for him. Chandrasekhara Venkata Raman (1888-1970) was then the Director of the Institute. Bhabha was made a Professor in 1944. Vikram Sarabhai (1919-71) also spent a short period at the Institute when Bhabha was there. At the Indian Institute of Science Bhabha guided research on cosmic rays. He organised a group of young researchers in experimental and theoretical aspects of cosmic ray research. After spending a few years in India Bhabha was no longer interested in going back to England. Perhaps this was because of his growing sense of responsibility towards his motherland. Gradually he became convinced that it was his duty to build up research groups in the frontier of scientific knowledge. On April 20, 1944, Bhabha in a letter to Subrahmanyan Chandrasekhar (1910-95) wrote: "...I have recently come to the view that provided proper appreciation and financial support are forthcoming, 'it was one's duty to stay in one's country and build up schools comparable with those that other countries are fortunate in possessing."

In the early 1940s when Bhabha was working at the Indian Institute of Science, there was no institute in the country which had the necessary facilities for original work in nuclear physics, cosmic rays, high energy physics, and other frontiers of knowledge in physics. This prompted him to send a proposal in March 1944 to the Sir Dorab J. Tata Trust for establishing 'a vigorous school of research in fundamental physics'. In his proposal he wrote : "There is at the moment in India no big school of research in the fundamental problems of physics, both theoretical and experimental. There are, however, scattered all over India competent workers who are not doing as good work as they would do if brought together in one place under proper direction. It is absolutely in the interest of India to have a vigorous school of research in fundamental physics, for such a school forms the spearhead of research not only in less advanced branches of physics but also in problems of immediate practical application in industry. If much of the applied research done in India today is disappointing or of very inferior quality it is entirely due to the absence of sufficient number of outstanding pure research workers who would set the standard of good research and act on the directing boards in an advisory capacity ... Moreover, when nuclear energy has been successfully applied for power production in say a couple of decades from now, India will not have to look abroad for its experts but will find them ready at hand. I do not think that anyone acquainted with scientific development in other countries would deny the need in India for such a school as I propose.

"The subjects on which research and advanced teaching would be done would be theoretical physics, especially on fundamental problems and with special reference to cosmic rays and nuclear physics, and experimental research on cosmic rays. It is neither possible nor desirable to separate nuclear physics from cosmic rays since the two are closely connected theoretically."

The trustees of Sir Dorab J. Tata Trust decided to accept Bhabha's proposal and financial responsibility for starting the Institute in April 1944. Mumbai (then Bombay) was chosen as the location for the prosed Institute as the Government of Bombay showed interest in becoming a joint founder of the proposed institute. The institute, named Tata Institute of Fundamental Research, was inaugurated in 1945 in 540 square metres of hired space in an existing building. In 1948 the Institute was moved into the old buildings of the Royal Yacht club. The present building of the Institute was inaugurated by Pt. Jawaharlal Nehru in January 1962. Nehru had earlier laid its foundation stone in 1954. While inaugurating the building in 1962 Nehru said : "Normally speaking, a delay of eight years in completing this structure seems rather excessive. But coming once in-between and today, going around partly over this building, my original impulse to criticise the delay was considerably modified because it has been a great effort to put this up as it has been done. There have been difficulties and anyhow the result achieved is something very much worthwhile." The Institute received financial support from the Government of India from its second year, through the Council of Scientific and Industrial Research (CSIR) and the Ministry of Natural Research and Scientific Research. Today the main financial support for the Institute comes from the Government of India through the Department of Atomic Energy. It should be emphasised here that no organisational chart for future development was prepared for TIFR. Bhabha picked up the right kind of people first and then gave them opportunities to grow. The same kind of principle that was followed by the Kaiser Wilhelm Society while building the Max Planck Institute in Germany: "The Kaiser Wilhelm Society shall not first build an institute for research and then seek out the suitable man but shall first pick up an outstanding man, and then built and institute for him". In this context the following observations made by Bhabha in his speech at the annual meeting of the National Insitute of Sciences of India (which was leater renamed as Indian National Science Academy) in October 1963 are worth noting. Bhabha said: "I feel that we in India are apt to believe that good scientific institutions can be established by Government decree or order. A scientific institution, be it a laboratory or an academy, has to be grown with great care like a tree. Its growth in terms of quality and achievement can only be accelerated to a very limited extent. This is a field in which a large number of mediocre or second rate workers cannot make up for a few outstanding ones, and the few outstanding ones always take at least 10-15 years to grow.

Too many of our National Laboratories have been established by deciding upon the field in which it was desired to work and by drawing up an organisational chart on the pattern of some corresponding large laboratory abroad. It was then assumed naively, that the posts in the chart could be filled by advertisement, forgetting that workers of the appropriate and high level either do not exist in India, or can only be obtained at the cost of some other institution, which thus becomes weaker of it. Our Universities, weak as they always were, have been further weakened in this matter."

The first step towards organising research in atomic energy was the creation of a Board of Research on Atomic Energy that was constituted as a part of CSIR with Bhabha as its Chairman. While proposing to create a Department of Scientific and Industrial Research (DSIR) as a full-fledged department of Government Shanti Swarup Bhatnagar (1884-1955) proposed that the Board of Research on Atomic Energy be shifted to the newly proposed Department. However, Bhabha had his own ideas. He felt that the atomic energy programme should be kept outside this new department. On April 26, 1948 Bhabha sent a note entitled 'Organisation of Atomic Research in India' to the then Prime Minister of India, Jawaharlal Nehru. In this note Bhabha wrote: "The development of atomic energy should be entrusted to a very small and high powered body composed of say, three people with executive power, and answerable directly to the Prime Minister without any intervening link. For brevity, this body may be referred as the Atomic Energy Commission". Bhabha emphasised that the proposed Atomic Energy Commission should have "its own secretariat independent of the secretariat of any other ministry or department of the government, including the envisaged Department of Scientific and Industrial Research". He also suggested that once the Commission was appointed the existing Board of Research on Atomic Energy should be abolished. The Government of India accepted Bhabha's proposal within a few months after its submission and with the promulgation of the Indian Atomic Energy Act 1948, the Atomic Energy Commission was formed in August 1948 with the following charter:

1. "To take such steps as may be necessary from time to time to project the interests of the country in connection with Atomic Energy by exercise of the powers conferred on the Government of India by the provisions of the Atomic Energy Act.
   
   
2. To survey the territories of the Indian Dominion for the location of useful minerals in connection with Atomic Energy; and
   
   
3. To promote research in their own laboratories and to subsidise such research in existing institutions and universities. Special steps will be taken to increase teaching and research facilities in nuclear physics in the Indian universities." The first Atomic Energy commission had three members with Bhabha as its Chairman. The other members were Shanti Swarup Bhatnagar and Kariamanikkam Srinivasa Krishnan (1898-1961).

The first three things that Bhabha felt necessary for putting India's nuclear programme on a sound footing were:

• The survey of natural resources, particularly materials of interest to atomic energy programme such as uranium, thorium, beryllium, graphite etc. To achieve this a special unit, Rare Minerals Division was created at Delhi with the help of Darashaw Nosherwan Wadia (1883-1969).
  
  
• Development of strong research schools in basic sciences particularly physics, chemistry and biology by providing facilities to and training up high quality research scientists.
  
  
• Development of a programme for instrumentation particularly in electronics. A unit called Electronics Production Unit was started in TIFR, which later formed the nucleus of the large corporation known as Electronics Corporation of India Limited (ECIL) at Hyderabad.

When Bhabha realised that technology development for the atomic energy programme could no longer be carried out within TIFR he decided to build a new laboratory entirely devoted to this purpose. He managed to acquire 1200 acres of land at Trombay, near Bombay for this purpose. Thus the Atomic Energy Establishment started functioning in 1954. The same year the Department of Atomic Energy (DAE) was also established.

Bhabha was elected a Fellow of the Royal Society in 1941. In 1943 he was awarded the Adams Prize by the Cambridge University for his work on cosmic rays, and in 1948 the Hopkins prize of the Cambridge Philosophical Society. In 1963 he was elected Foreign Associate of the U.S. National Academy of Sciences, and Honorary Life Member of the New York Academy of Sciences. In 1964 he was made Foreign Corresponding Academician of the Royal Academy of Sciences, Madrid. From 1960 until 1963 he was President of the International Union of Pure and Applied Physics. He was president of the historic International Conference of the Peaceful uses of atomic energy held, under U.N. auspices, at Geneva in August, 1955. Bhabha was President of the National Institute of Sciences of India in 1963 and President of the Indian Science Congress Association in 1951. He was awarded the title of Padma Bhushan by the Government of India in 1954.

Bhabha was killed in an air-crash near the famous Mont Blanc peak of the Alps on January 24, 1966, while he was on his way to Vienna to attend a meeting of the Scientific Advisory Committee of the International Atomic Energy Agency. At the time of his death, Bhabha was Director and Professor of Theoretical Physics of the Tata Insitute of Fundamental Research, Secretary to the Government of India in the Department of Atomic Energy, ex-officio Chairman of the Indian Atomic Energy Commission, and Director of the Atomic Energy Establishment at Trombay. We would like to conclude the sketchy and perhaps incoherent account of Bhabha's life and work by quoting J R D Tata on Bhabha: "Scientist, engineer, master-builder and administrator, steeped in humanities, in art and music, Homi was a truly complete man".