India has had a long legacy of important contributions to science, that we are all immensely proud of. The world may think little of them but names like Dr. C. V. Raman, Ramanujan, Dr. Homi J. Bhabha, and, Satyendra Nath Bose still inspire Indian Researchers. However, you don’t have to look closely at any list of Famous Indian Scientists to notice that something is missing. The Women.
It is difficult to see the stars when the moon is bright, and easy for us to forget the contributions of a lot of people because they were overshadowed by a few. A lot of Indian Women have contributed to the fields of Science without their names listed in the books. Today, I wish to talk about one such person, Bibha Chowdhuri.
Talking about prominent people in science is incomplete without discussing the Nobel Prize and The Royal Society. Nobel Prize is not only about the fame, it is about prestige and legacy of how science evolves and how the future generations perceive it. However, there have been a few missteps along the way. This story is one of them.
Bibha Chowdhuri was born in 1913 in Kolkata, India (British Raj). She was from an educated zamindar (landlord) family with ties to Sir Jagdish Chandra Bose. She was the third eldest child, and had four sisters and a brother. Her mother Urmila Devi was daughter of a Brahmo Samaj Missionary, because of that Bibha and her siblings were all well-educated. Brahmo Samaj is a religious group known for liberal leanings and then radical beliefs like women should be allowed education. It is interesting to note that Neither Bibha nor her siblings ever married. Brahmo Samaj has conflicts with Hinduism and prefer to marry in their own religion. Related difficulties in finding matches could be a contributing factor. However, it is important to consider that almost 14% of women scientists never marry. According to most accounts, she led a very simple life, focusing more on her research and books during her youth. In her later years she had good relationships with a lot of prominent scientists of her time.
She attended Bethune School in Kolkata, which is one of the oldest girls’ schools in Asia. It was established by John Elliot Drinkwater Bethune, the first female college in India is also named after him. She attained B.Sc. degree with Honors in Physics from Scottish Church College in Kolkata. Alumni of this college include the likes of Swami Vivekananda and Netaji Subhas Chandra Bose. Not much is known about her early life.
She completed her MSc in Physics from University of Calcutta in 1936(at 23 years old), being only woman in her batch. She took a deep dive into her research immediately after that. Bibha was related to Dr. Debendra Mohan Bose (Dr. Bose) from her mother’s side. Dr. Bose was nephew of famous physicist Jagadish Chandra Bose, and the future Director of Bose Institute of Kolkata. She approached Dr. Bose, requesting to join his research group studying subatomic particles. Dr. Bose was reluctant despite the family connection, he did not think he had projects suitable to be assigned to a woman. Dr. Bose was later convinced and allowed her to join. When Dr. Bose moved from University of Calcutta to Bose Institute, she moved with him (among his other fellows) and continued her research. She worked at the Bose Institute from 1938 till 1942 or 1945 (speculated). During this period, she published three consecutive papers in Nature in collaboration with Dr. Bose.
The field of particle physics has always been limited by the technology of its time. Back when she was doing her research into high energy particles, no particle accelerators were available. The only source of such particles for research was cosmic rays. She did extensive research using cloud chambers. It is an instrument which keeps chemicals like ethanol in vapor state allowing you to observe particles going through the chamber via disturbance lines caused. Think of those jet trails from flights. You can figure out a lot based on the path a particle takes in such the chamber. Such trails are very temporary, one can only observe a trail for a few seconds at most, not enough to do any calculations. She and Dr. Bose utilized photographic plates to develop a method to study high energy particles. They (or their staff) took several batches of half-tone plates to two mountains in now West Bengal and exposed to Cosmic Rays. They had one setup at Sandakphu (12000 ft.) and another in Pharijong (15000 ft).
She studied the developed plates under a microscope and compared them to control samples exposed to known particles. She observed two new particles and calculated their average mass. She had discovered pi-masons, or pions and mu-mesons or muons. These particles had been predicted to exist but there hadn’t been clear experimental confirmation. She also calculated the mass of these particles as approximately 221 times and 278 times the mass of an electron. Her and DM Bose published this in various journals including ‘Nature’.
She could not continue her research due to unavailability of better plates and equipment due to the World War II. Seven years after her discovery, British physicist, Dr. Cecil Frank Powell won the Nobel “for his development of the photographic method of studying nuclear processes and his discoveries regarding mesons made with this method”. In his later written book, Dr. Powell acknowledged Bibha and C M Bose’s work. Powell was later elected a Fellow of the Royal Society (FRS). Dr. Powell’s final calculations for the mass using better plates were 214 and 290 times the mass of an electron.
She moved to Manchester in 1945 to work under her Doctoral advisor Sir Patrick Blackett, another Fellow of the Royal Society. Her research was into extensive air showers. When a high energy cosmic particle collides with a nucleus from earth’s atmosphere, it causes a shower of subatomic particles. She used a device invented by Sir Patrick, a counter controlled cloud chamber for her experiments. Bibha submitted her thesis in early 1949 (at the age of 36) and earned her doctorate degree in 1952 (at the age of 39). The title of ‘First Indian Woman to earn a PhD in Physics’ is toss-up between Bibha and Kamala Sohonie. Kamala Sohonie was a biochemist who was discriminated against by the ‘famous’ Dr. C V Raman. Dr. Bibha’s advisor Sir Blackett went on to win the Nobel Prize in Physics for his work on cosmic rays and invention of the new cloud chamber. Dr. Bibha’s contributions to his observations and discoveries related to strange particles (actual name) are unknown.
Dr. Bibha came back to India after this. Dr Homi J. Bhabha recruited her into Tata Institute of Fundamental Research in 1949, as he was also working in the field of Cosmic Rays at that time. She was the first woman scientist hired by TIFR. Dr. Bibha joined as a research fellow in an Experimental Physics group working on cloud chambers. Dr. Bibha continued her research into extensive air showers using lead plates and cloud chambers. She devised new methods to observe particles and their properties.
Dr. Bibha left TIFR in December 1953 to briefly work at the Bengal Engineering College in Kolkata. She later joined Physical Research Laboratory (PRL) in Ahmedabad at a time when Dr. Vikram Sarabhai was its Director. She was involved in the Kolar Gold Field (KGF) experiments. They used indigenously developed sub-atomic detectors placed 700ft underground which worked in conjunction with the Extensive Air Shower array of TIFR to conduct experiments. She was involved in the setup of the experiment, arranging the site and accommodation for her assistants. She had discussed her plans to set up another experiment at Mount Abu on radio frequency emissions with Dr. Vikram Sarabhai.
After the untimely demise of Dr. Sarabhai, her new experiment was denied permission by PRL. Her contributions to KGF Experiments have since been erased from history. It appears as if she published no papers in the 14 years that she worked there. Papers written during the time by her colleagues at the experiments she helped setup, fail to mention Dr. Bibha’s contributions.
She retired from PRL after this and continued her research into high energy particles. She continued to be a visiting scientist in collaboration with scientists of Saha Institute of Nuclear Physics, University of Calcutta and Indian Association for the Cultivation of Science. She continued to publish her research until her death at 78 in 1991. Last of her papers was published in 1990.
Her collaborators and fellows went on to get national recognition, awards and prestigious positions for the experiments at KGF and TIFR. Dr. Bibha was never granted any prestigious fellowships, or received any major awards in her lifetime or since. Despite working with some of the leading physicists in the world, Dr. Bibha remains an unknown name in field of Subatomic Particles.
We know about her and her works in most parts because of research by Rajinder Singh, and Suprakash C. Roy. Without their efforts we would not know of this untold legend, the star named Dr. Bibha Chowdhuri. Women of our generation can now read about her and take inspiration from her story. While it is better now than in her time, the struggle hasn’t changed much in over a hundred years. To quote her “it is a tragedy that we have so few women physicists today”.
Cover Art by @at_rv (bhairavibala.com)