Homi Jehangir Bhabha, FRS (30 October 1909 – 24 January 1966) was an Indian nuclear physicist, founding director, and professor of physics at the Tata Institute of Fundamental Research (TIFR).[2] Colloquially known as “Father of the Indian nuclear programme“,[3] Bhabha was also the founding director of the Atomic Energy Establishment, Trombay (AEET) which is now named the Bhabha Atomic Research Centre in his honour. TIFR and AEET were the cornerstone of Indian development of nuclear weapons which Bhabha also supervised as director.[3]
Homi Bhabha was awarded the Adams Prize (1942) and Padma Bhushan (1954). He was also nominated for the Nobel Prize for Physics in 1951 and 1953–1956.[4]
Early life and education[edit]
Homi Jehangir Bhabha was born into a prominent wealthy Parsi family, through which he was related to businessmen Dinshaw Maneckji Petit.[5] He was born on 30 October 1909. His father was Jehangir Hormusji Bhabha, a well known Parsi lawyer and his mother was Meheren.[6] He received his early studies at Bombay’s Cathedral and John Connon School and entered Elphinstone College at age 15 after passing his Senior Cambridge Examination with Honours.
He then attended the Royal Institute of Science in 1927 before joining Caius College of Cambridge University. This was due to the insistence of his father and his uncle Dorabji, who planned for Bhabha to obtain a degree in mechanical engineering from Cambridge and then return to India, where he would join the Tata Steel or Tata Steel Mills in Jamshedpur as a metallurgist.
Further studies[edit]
Bhabha’s father understood his son’s predicament, and he along with his wife agreed to finance his studies in mathematics provided that he obtain first class on his Mechanical Sciences Tripos exam. Bhabha sat the Tripos exam in June 1930 and passed with first class honours. Meanwhile, he worked at the Cavendish Laboratory while working towards his PhD degree in theoretical physics. At the time, the laboratory was the centre of a number of scientific breakthroughs. James Chadwick had discovered the neutron, John Cockcroft and Ernest Walton transmuted lithium with high-energy protons, and Patrick Blackett and Giuseppe Occhialini used cloud chambers to demonstrate the production of electron pairs and showers by gamma radiation. During the 1931–1932 academic year, Bhabha was awarded the Salomons Studentship in Engineering. In 1932, he obtained his first-class on his Mathematical Tripos and was awarded the Rouse Ball travelling studentship in mathematics. During this time, nuclear physics was attracting the greatest minds and it was one of the most significant emerging fields as compared to theoretical physics, the opposition towards theoretical physics attacked the field because it was lenient towards theories rather than proving natural phenomenon through experiments. Conducting experiments on particles which also released the enormous amounts of radiation, it was a lifelong passion of Bhabha, and his leading-edge research and experiments brought great laurels to Indian physicists who particularly switched their fields to the nuclear physics, one of the most notable being Piara Singh Gill.
Work in nuclear physics[edit]
In January 1933, Bhabha received his doctorate in nuclear physics after publishing his first scientific paper, “The Absorption of Cosmic radiation“. In the paper, Bhabha offered an explanation of the absorption features and electron shower production in cosmic rays. The paper helped him win the Isaac Newton Studentship in 1934, which he held for the next three years. The following year, he completed his doctoral studies in theoretical physics under Ralph H. Fowler. During his studentship, he split his time working at Cambridge and with Niels Bohr in Copenhagen. In 1935, Bhabha published a paper in the Proceedings of the Royal Society, Series A, in which he performed the first calculation to determine the cross section of electron-positron scattering. Electron-positron scattering was later named Bhabha scattering, in honour of his contributions in the field.
In 1936, with Walter Heitler, he co-authored a paper, “The Passage of Fast Electrons and the Theory of Cosmic Showers”[7] in the Proceedings of the Royal Society, Series A, in which they used their theory to describe how primary cosmic rays from outer space interact with the upper atmosphere to produce particles observed at the ground level. Bhabha and Heitler then made numerical estimates of the number of electrons in the cascade process at different altitudes for different electron initiation energies. The calculations agreed with the experimental observations of cosmic ray showers made by Bruno Rossi and Pierre Victor Auger a few years before. Bhabha later concluded that observations of the properties of such particles would lead to the straightforward experimental verification of Albert Einstein‘s theory of relativity. In 1937, Bhabha was awarded the Senior Studentship of the 1851 exhibition, which helped him continue his work at Cambridge until the outbreak of World War II in 1939.