Homi Jehangir Bhabha (30 October 1909 – 24 January 1966) was an Indian nuclear theoretical physicist who is widely credited as the "father of the Indian nuclear programme". He was the founding director and professor of physics at the Tata Institute of Fundamental Research (TIFR), as well as the founding director of the Atomic Energy Establishment, Trombay (AEET) which was renamed the Bhabha Atomic Research Centre in his honour. TIFR and AEET served as the cornerstone to the Indian nuclear energy and weapons programme. He was the first chairman of the Indian Atomic Energy Commission (AEC) and secretary of the Department of Atomic Energy (DAE). By supporting space science projects which initially derived their funding from the AEC, he played an important role in the birth of the Indian space programme.
Bhabha was awarded the Adams Prize (1942) and Padma Bhushan (1954), and nominated for the Nobel Prize for Physics in 1951 and 1953–1956. He died in the crash of Air India Flight 101 in 1966, at the age of 56.
Early life
Childhood Homi Jehangir Bhabha was born on 30 October 1909 into a wealthy Parsi family comprising Jehangir Hormusji Bhabha, a well-known lawyer, and Meherbai Framji Panday, granddaughter of Sir Dinshaw Maneckji Petit. He was named Hormusji after his paternal grandfather, Hormusji Bhabha, who was Inspector-General of Education in Mysore. He received his early studies at Mumbai's Cathedral and John Connon School.
Bhabha's upbringing instilled in him an appreciation for music, painting and gardening. He often visited his paternal aunt Meherbai Tata, who owned a Western classical music collection which included the works of Beethoven, Mozart, Haydn and Schubert. Together with his brother and his cousin, it was a ritual for him to listen to records from this collection over the gramophone. Bhabha also received special violin and piano lessons.
His tutor in sketching and painting was the artist Jehangir Lalkala. At seventeen, Bhabha's self-portrait won second place at the prestigious Bombay Art Society's exhibition.
Tending to a terrace garden of exotic plants and cross-bred Bougainvillea and Roses, Hormusji was an expert on trees, plants and flowers. He kept books on gardening in the house's large private library.
Bhabha showed signs of precocity in the sciences. As a child, he spent hours playing with Meccano sets, and was fond of building his own models rather than following the booklets that accompanied the sets. By fifteen, he had studied general relativity.
Bhabha frequently visited the home of his uncle Dorabji Tata, chairman of the conglomerate Tata Group and then one of the wealthiest men in India. There, he was privy to conversations Dorabji had with national leaders of the independence movement, like Mahatma Gandhi and Motilal Nehru, as well as business dealings in industries like steel, heavy chemicals and hydroelectric power which the Tata Group invested in. John Cockcroft remarked that overhearing these conversations should have inspired Bhabha's career as a scientific organizer.Science Reporter, CSIR, October 1996, Commemorative volume— tributes from eminent scientists and colleagues from India and abroad.
University studies in India Though he passed his Senior Cambridge Examination with honours at the age of fifteen, he was too young to join any college abroad. So, he enrolled in Elphinstone College. He then attended the Royal Institute of Science in 1927, where he witnessed a public lecture by Arthur Compton, who would win the Nobel Prize in physics the next year for his 1923 discovery of the Compton effect. Bhabha later said that he first heard of cosmic rays, the subject of his future research, at this lecture.
University studies in Cambridge The following year, he joined Gonville and 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 mills in Jamshedpur as a metallurgist. Within a year of joining Cambridge University, Bhabha wrote to his father: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.Homi Jehangir Bhabha . Vigyanprasar.gov.in. Retrieved on 30 June 2015.Sympathetic to his son's predicament, Bhabha's father agreed to finance his studies in mathematics provided that he obtain first class on his Mechanical Tripos. Bhabha sat the Mechanical Tripos in June 1930 and the Mathematics Tripos two years later, passing both with first-class honours.
Bhabha coxed for his college in boat races and designed the cover of his college magazine the Caian. He also designed the sets for a student performance of Pedro Calderón de la Barca's play Life is a Dream and Mozart's Idomeneo for the Cambridge Musical Society. Encouraged by the English artist and art critic Roger Fry, who praised his sketches, Bhabha seriously considered becoming an artist. However, exposure to work being done at the Cavendish Laboratory at the time motivated Bhabha to focus on theoretical physics. When he registered as a research student in mathematics, he decided to change his name to Homi Jehangir Bhabha, the name he would keep for the rest of his life.
Early research in nuclear physics Bhabha worked at the Cavendish Laboratory while working towards his PhD degree in theoretical physics supervised by Ralph Fowler. At the time, the laboratory was the centre of several breakthroughs in experimental physics. James Chadwick had discovered the neutron, John Cockcroft and Ernest Walton had transmuted lithium with high-energy protons, Francis Aston had discovered chemical isotopes, and Patrick Blackett and Giuseppe Occhialini had used cloud chambers to demonstrate the production of electron pairs and showers by gamma radiation.
In 1931, Bhabha held the Salomons studentship in engineering. In 1932, on a Rouse Ball travelling studentship, he visited Copenhagen, Zurich and Utrecht. Niels Bohr's institute at Copenhagen was a major hub of theoretical physics research. At Zurich, Bhabha wrote his first paper in July 1933 with Wolfgang Pauli, which was published in the Zeitschrift fur physik in October 1933. During his studentship, Bhabha also visited Hans Kramers, who was then a professor conducting theoretical research in the interaction of electromagnetic waves with matter at Utrecht University. In 1933, Bhabha was selected for the Isaac Newton scholarship, which he held for the next three years and used to fund his time working with Enrico Fermi at the Institute of Physics in Rome. The same year, Bhabha published his first paper on the role of electron showers in absorbing gamma radiation.
The discovery of the positron in 1932 and the formulation of Dirac's hole theory to explain its properties had catalysed the creation of the field of high-energy physics. Bhabha chose to make this field the focus of his career, publishing over fifty papers on the topic during his lifetime. He played a key role in the early development of quantum electrodynamics.
Bhabha received his doctorate in nuclear physics in 1935 for his thesis titled "On cosmic radiation and the creation and annihilation of positrons and electrons".
In 1935, Bhabha published a paper in the Proceedings of the Royal Society in which he first calculated the cross-section of electron-positron scattering. Electron-positron scattering was later named Bhabha scattering after him.
In 1937, with Walter Heitler, he co-authored a paper, "The passage of fast electrons and the theory of cosmic showers" 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 and Heitler postulated that the penetrating component of cosmic radiation comprised "heavy electrons", most of which "must have masses nearer to hundred times the electron mass". The paper was announced in a letter in Nature.
The same year, Seth Neddermeyer and Carl David Anderson, among others, also reached similar conclusions in independently published papers in Physical Review. Before pions were discovered, observers often confused muons with mesons. When Bhabha's collaborator Heitler made him aware of Hideki Yukawa's 1935 paper on the theory of the meson, Bhabha realized that this particle was the postulated "heavy electron". In a 1939 note to Nature, Bhabha argued the particle should be christened the "meson" in line with the word's Greek etymology, not "mesotron" as Anderson had proposed. Bhabha later concluded that observations of the properties of the meson would lead to the straightforward experimental verification of the time dilation phenomenon predicted by Albert Einstein's theory of relativity.
So far, Bhabha's work had been supported by the Senior Studentship of the 1851 exhibition, which he had received for three years, starting in 1936, while continuing to be based in Gonville and Caius College. In 1939, Bhabha was awarded a Royal Society grant to work in P. M. S. Blackett's laboratory in Manchester. However, when World War II broke out, Bhabha found himself unable to return to England to take up the assignment.
Career
Indian Institute of Science Bhabha had returned to India for his annual vacation before the start of World War II in September 1939. War prompted him to remain in India, where he accepted a post of reader in physics at the Indian Institute of Science in Bengaluru headed by Nobel laureate C.V. Raman. In 1940, the Sir Dorabji Tata Trust supported his experimental cosmic ray physics research with a grant.
Bhabha was made a Fellow of the Royal Society in 1941, and the following year he became the first Indian to receive the Adams Prize. Soon after receiving the Adams Prize, Bhabha was also made a Fellow of the Indian Academy of Sciences and President of the Physics section of the Indian Sciences Congress. While introducing him at the 1941 Annual Meeting of the Indian Academy of Sciences, C.V. Raman described the 32-year-old Bhabha as "the modern equivalent of Leonardo da Vinci". On 20 January 1942, Bhabha formally accepted professorship and leadership of the Cosmic Ray Research Unit.