Homi Jehangir Bhabha Visionary Scientist and Institution Builder M.V.N. Murthy, The Institute of Mathematical Sciences, Chennai The year 2009 marks the birth centenary of Homi Jehangir Bhabha--a physicist, an artist, a visionary and an institution builder par excellence. Bhabha's eventful life came to an abrupt end when he died in an air crash near Mont Blanc mountains in the Alps in 1966. He left behind a legacy of lasting contribution to Indian science and Institutions which continues to this day and remains an inspiration for others to follow. Early years Bhabha was born in Bombay, now known as Mumbai, on October 30 1909, into a wealthy Parsi family which was also directly linked to many other families instrumental in establishing industries and educational institutions in colonial India. He had his early education in Bombay's Cathedral School and later entered Elphinstone College. As his father wished, Bhabha first obtained a degree in Mechanical Engineering from Cambridge University but his passion lay elsewhere. Cambridge University in England, in the early thirties, was a great place for an young man like Bhabha since it was home to many great scientists of that time. The discoverer of the atomic nucleus, Ernest Rutherford, was there as also Paul Dirac, one of the founders of modern quantum mechanics. It was no surprise therefore that Bhabha got interested in mathematics and theoretical Physics. He therefore wrote to his father "...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. ...It is no use saying to Beethoven 'You must be a scientist for it is a great thing' when he did not care two hoots for science; or to Socrates 'Be an engineer; it is the work of an intelligent man'. It is not in the nature of things. I therefore earnestly implore you to let me do physics." Fortunately for Bhabha, his father understood his son's situation and allowed him to pursue his passion. He first studied under the guidance of Paul Dirac, the Lucasian Professor of Mathematics (a position occupied by Isaac Newton in the 18th century) and completed his Ph.D with R.H. Fowler (who also guided the renowned astrophysicist, S. Chandrasekar from India) in 1935. During this time he also interacted with renowned physicists Wolfgang Pauli in Zurich, Enrico Fermi in Rome and Niels Bohr in Copenhagen. Bhabha returned to India in 1939 intending to go back to Europe and take up a position. But that did not happen, fortunately. Turning point Any war amongst peoples and countries is terrible, especially the World War II which resulted in enormous destruction and death of people. However, in Bhabha's case the war intervened in a different way, he could not go back to Europe which he intended to do after a brief holiday in India. He decided to stay back and the decision was a turning point not only for Bhabha but also for the advancement of Science and Technology in India after Independence. Nobel Laureate C.V.Raman offered Bhabha a position in the Indian Institute of Science which Bhabha accepted. He gathered a group of students to work with him in the area of theoretical physics. Simultaneously he also started experimental work in Cosmic Ray physics which is rather unusual for a trained theoretical physicist. Rather unusual was also Bhabha's vision about the development of Science and Technology in India. He realised the importance of setting up an Institution devoted to the pursuit of fundamental research in the emerging areas of nuclear science, cosmic rays etc, as also in such deeply formal and theoretical fields such as mathematics. With financial support from the Dorab Tata Trust and the Maharashtra government, he set up the Tata Institute of Fundamental Research (TIFR) in June 1945. TIFR was inaugurated at IISc in Bangalore before moving to Bombay. In a rather short period of time Bhabha gathered a team of young and enthusiastic scientists. The Institute was also visited by such leading scientists as Paul Dirac, Hans Bethe, Niels Bohr, and Wolfgang Pauli, to name a few, who interacted with the young students that Bhabha had collected. It was Bhabha's vision that TIFR should become the fountainhead of basic research in India which indeed it has become. Not only that, as Bhabha himself later said, TIFR was also the `cradle of the Atomic Energy Programme' of the country. Bhabha also encouraged research in astronomy, space science, computer science and biology in TIFR. It is not surprising that in each of these fields, new and dedicated Institutions have emerged, testifying to the vision of Bhabha. TIFR therefore was not just the cradle of the atomic energy programme but incubated many more institutions in line with Bhabha's vision. Very early on, Bhabha initiated the atomic energy research programme in India. This lead to the formation of the Atomic Energy Establishment in Bombay. After Bhabha's death in 1966, this was renamed as the Bhabha Atomic Research centre (BARC). It was Bhabha's vision that everything that was needed for the programme should be developed in the country itself--the idea of self-reliance which found a willing ally in the then Prime Minister Jawaharlal Nehru. He started the famous Atomic Energy Establishment training school with a view to create a scientific human resource when he realised that the most important resource for any success is people. Many eminent scientists have come out of the training school contributing not only to the atomic energy programme, but also to several diverse fields in the country. It is no wonder therefore that Bhabha is known as the "Father of India's Atomic Energy Programme". He was also the first president of the United Nations conference on the peaceful uses of atomic energy, held in Geneva in 1955. He advocated international control of nuclear energy and the outlawing of atomic bombs by all countries. His vision was to use nuclear energy for alleviating poverty and misery of people. Bhabha was a multi-faceted personality. Not only was he a scientist, institution builder, skilled administrator and reformer of education system, he was also an artist of repute interested in finer aspects of life. His sketches of famous scientists are also well known. ---------------------------------------------------------------------- BOX Bhabha's scientific contributions Bhabha was interested in cosmic rays, a name given by Millikan, from the beginning of his research career. Cosmic rays are energetic particles arriving from the depths of space that impinge on Earth's atmosphere, producing cascades of particles, or showers, not necessarily found in the original cosmic rays. About 90 percent of all the incoming cosmic ray particles are protons or hydrogen nuclei, almost 10 percent are helium nuclei (alpha particles), and slightly under 1 percent are heavier elements and electrons. The very first work by Bhabha was concerned with the absorption and production of further showers of particles by cosmic rays. Later Bhabha in collaboration with Walter Heitler formulated what is called the "cascade theory of the electron". In this a very high energy electron passing through matter produces photons (another name for light) which in turn produce pairs of electrons and anti-electrons; the process continues with production of more photons, hence the name cascade, until all the available energy is utilised. Bhabha continued to have a lifelong interest in cosmic ray research and was instrumental in building a deep underground laboratory in Kolar Gold Fields apart from initiating surface-based and high-altitude balloon experiments for measuring the cosmic ray composition and energies at various depths in the atmosphere and even under the earth. Bhabha was the first to calculate the probability (and cross-section) for electron scattering on an anti-electron (positron). This process is now called Bhabha scattering in his honour. Though less known, Bhabha was also the first to propose the existence of muon, a heavier version of the electron, to explain the penetrating component of the cosmic ray-induced secondary particles in the atmosphere. Photo: Einstein, Albert; Yukawa, Hideki; Wheeler, John Archibald; Bhabha, Homi Jehangir