PERSONAL NEWS Yash Pal (1926–2017) In the evening hours of Monday, 24 July Yash was born in the small town of perhaps even more importantly, Nirmal 2017 Professor Yash Pal the educator Jhang, on the eastern banks of the Sharma who was a fellow student. Nir- and scientist passed away. Nirmal, who Chenab River in Punjab on 26 November mal was a courageous and brilliant has known him for 75 years, and was his 1926, to a prosperous family with highly young girl, with a sparkling good hu- constant companion and wife for 64 ethical and cultural values. His father mour that lights up her face even today. years, and their two sons, Anil and Rahul Ram Pyare Lal Bhutani was a Gazetted Yash was captivated; they became good are deeply saddened by this loss and my Officer in the Central Government under friends. The year was 1943. heart goes out to them. Millions of per- the British rule, a well-respected posi- At that time World War II was raging sons, scientists, administrators, people in tion, and his mother Lakshmi Devi was a in Europe and Africa in the West, and in the villages of India, students, children highly intelligent and generous lady. Burma and Rangoon in the East, and the and indeed the widest spectrum of people Yash was the eldest of five siblings, with civil disobedience movement demanding we can think of are touched by his de- a sister Swarn, and three brothers, Om independence for India from British rule mise. Such was the life of Yash Pal, and Prakash, Rajinder Kumar and Sunil, who was gathering strength. Amidst all this, such was his personality that everyone Yash completed the Intermediate stage individually felt a personal bond with (F.Sc.), and imbibed the patriotic spirit, him. He was a man of fine aesthetic sen- and assimilated ideas of egalitarianism sibilities and egalitarian principles. and ahimsa advocated by leaders like Words cannot assuage the sorrows of this Mahatma Gandhi and Pandit Jawaharlal loss; only time will work its alchemy to Nehru. He read Nehru’s autobiography convert our pathos into fond memories, Towards Freedom (written in the Almora and a celebration of his wonderful and prison), Tolstoy and Thoreau. From extraordinary life. ‘He is gone, but his Lyallpur, Yash moved to Punjab Univer- values and wisdom will remain to guide sity, Lahore to enroll in B Sc (Physics us,’ said Shyam Narayan Tandon, his honors), and in the few years’ time he student and long-standing associate1. took to graduate and then enroll in the During his many splendored career master’s programme, the divisive feel- Yash Pal made pioneering contributions ings of hatred among different communi- to particle physics, to observational and ties, and the feverish demands for a theoretical study of astrophysics and division of India on religious lines had cosmic rays, to cosmology, to building of were all well educated, and have served vitiated the atmosphere. In June 1947, scientific and educational institutions, to the country admirably in various capaci- for his summer vacation Yash went to the national space programme, including ties. His primary education was in the New Delhi where his father had been to the application of space technology to city of Quetta in Balochistan where his transferred from Jabalpur. At midnight, remote sensing and to reaching out to father had been posted. Fortunately he as the fifteenth day in August com- every nook and corner of India to spread and his family survived the terrible 1935 menced Nehru proclaimed the independ- general education on subjects like health earthquake, which claimed more than ence of India from the ramparts of the and hygiene, animal husbandry and agri- 60,000 lives. This disrupted his studies Red-fort: ‘…at the midnight hour – when culture, to the popularization of science, for almost a year during which the city the whole world is asleep, India is to bring about inter-departmental coop- was rebuilt, allowing him to return to awake…’ There were celebrations all eration, and to infuse a self-confidence Quetta to complete his primary and sec- over India, but India had been partitioned into one and all of us that we can solve ondary school education. His father was into two countries, India with a wide dis- our problems, technological, societal transferred to Jabalpur on the banks of tribution of ethnicity and religions, and or political by our own efforts2–5. He the River Narmada, in the Central Prov- Pakistan with predominantly Muslims. contributed, in no small way, to bind us inces, and his education continued there. Riots had broken out and refugees of mi- together as a nation, poor or rich, villag- A silverlining in all this interrupted edu- nority population were pouring into In- ers or city dwellers, educated or other- cation was that he came under the influ- dia, which was not prepared and had to wise. Accordingly, talking about Yash ence of a great teacher, Pawar, who scramble to house them and feed them. Pal’s SITE experiment that ‘blossomed adopted the Socratic method in his teach- Yash was in the thick of it as a volunteer. into a full scale television facility con- ing instead of conventional lectures, and There was no question of his going back necting millions of villages of India’, introduced Yash Pal to self-study of to Lahore to complete his studies for the N. R. Narayana Murthy of Infosys Tech- various subjects. He matriculated with a Master’s degree; that was impossible. nologies says that SITE together with Secondary School Certificate in 1942. During this period he befriended many CDOT pioneered by Sam Pitroda have Fearing further such disruptions, the artists, students and intellectuals, and his transformed the lives of Indians like family decided to send Yash away to his friendship with Nirmal continued through never before, and have given us vibrant aunt’s house and continue his education those troubled times. With enterprise and TV media, and efficient communication in Lyallpur, better known today as Fais- help from great educators like D. S. systems on par with the best in the alabad. And this was where he met his Kothari, Yash and his friends continued world6. closest friend Mohindra Chadha, and their studies in makeshift classrooms. It 804 CURRENT SCIENCE, VOL. 113, NO. 4, 25 AUGUST 2017 PERSONAL NEWS is from such a crucible that Yash Pal Yash and Nirmal arrived at Rossi’s lab muon flavors generated by the decay of emerged with sterling character and where they were warmly welcomed by secondary cosmic-ray pions and kaons, dedicated to a life in science and service fellow research workers, Hale Bradt, followed by a prescription of how to de- to his fellowmen. Elihu Boldt, David Caldwell, George tect them in deep underground experi- In order to fulfill the requirement for Clark, Gaurang Yodh and Stanislaw Ol- ments21 are as relevant for the ongoing the Master’s degree he had to conduct bert, besides Bruno Rossi and Herb experiments even today, as they were for independent research, and write a disser- Bridge. Yash Pal continued his research the TIFR effort in the mines of Kolar by tation. Fortunately, he was able to secure studying the properties and decay charac- B. V. Sreekantan, M. G. K. Menon and a position as a research assistant at the teristics of neutral and charged K- others in the 1960s. A major effort for already famous Tata Institute of Funda- mesons, and of heavier particles called the studies of cosmic-ray neutrinos sub- mental Research, Bombay, founded by hyperons, which are produced in associa- sequently launched by the Japanese Homi Bhabha in 1945. When Yash Pal tion with K-mesons, now using energetic group, led to the discovery of neutrino joined the institute in 1949, he became particles generated in manmade particle oscillations, and the award of the Nobel close friends with another precocious accelerators. Nirmal took up a technical Prize for M. Koshiba. Such instances in- student, Devendra Lal, who was bub- position at MIT. The title and a brief dicate that he focused his research efforts bling with energy and impish humour. summary of Yash Pal’s doctoral thesis8 always on important questions, espe- The visit of Bernard Peters on a visit to submitted to MIT is given in Box 1. This cially on those whose solutions were not the institute in 1950, gave a fillip to their effort carried out with several members only possible but also imminent. The research: They floated a stack of photo- of Rossi’s group led to the publication of study of the cut-off in the cosmic ray graphic emulsion pellicles to altitudes of several important papers9–14. It may not spectrum induced by their interactions ~30,000 feet suspended from latex bal- be out of place here to note that in 1959, with a hypothetical neutrino background loons filled with hydrogen gas, to record Segre and Chamberlain were awarded the in the universe20 foreshadowed the cut- cosmic ray particles and their interac- Nobel Prize for the discovery of the anti- off in the cosmic-ray spectrum predicted tions. By that time such methods of re- proton, and in 1964, Christenson, Cronin, by Greisen, Zatsepin and Kuzmin owing search were well established by Cecil F. Fitch and Turlay in their continued study to their interactions with the 2.7 K uni- Powell of Bristol University, who had of the decay neutral K-mesons made versal microwave background. Once the discovered the ‘ meson’, the Yukawa the Nobel prize-winning discovery of the discovery of the background became particle responsible for the binding force violation of the combined symmetry of known in India, his group calculated the among protons and neutrons inside an parity and charge conjugation.