ISSN (Online) - 2349-8846 Remembering the Life of Satyendra Nath Bose AMITABHA BHATTACHARYA Amitabha Bhattacharya ([email protected]) is a retired IAS officer. Vol. 54, Issue No. 14, 06 Apr, 2019 1. Much of the information for this article has been obtained from the journal Science and Culture (January–February 2019), Kolkata. Editor-in-chief: Prof S C Roy, Guest editors for this special issue on “How Bose Statistics changed our Understanding of Matter”: Rabin Banerjee and Samit K Ray; and 2. Detailed accounts of 37 scientific papers of Bose are available in S N Bose: The Man and His Work (Part 1), S.N. Bose National Centre for Basic Sciences, Kolkata, 1994. Satyendra Nath Bose would have been 125-years-old on 1 January 2019. During our time as students in the turbulent 1960s in Calcutta, several stories about Satyendra Nath Bose's genius were circulated – some real and some coloured by imagination. We were told that he was among the few early scientists who understood the meaning and importance of Albert Einstein’s theories of relativity; that a teacher in his school awarded him 110 out of 100 in a paper and thought he would one day join the ranks of Karl Friedrich Gauss as a mathematician; that his university records were yet to be broken; that when Niels Bohr, during his lecture at Calcutta, got stuck with a problem, Bose instantly resolved it; and even that some students earned their PhDs based on scraps from his wastepaper basket! As distinct from the other two famous Boses (J C Bose who taught him at Presidency College and Debendra Mohan Bose who was a few years senior), S N Bose was essentially a theoretical, mathematical physicist. The eldest of the seven children of Amodini Bose and ISSN (Online) - 2349-8846 Surendranath Bose (who worked with the railways), Bose was born and educated in Calcutta. As a student, he stood first in Calcutta University. His illustrious classmates included Meghnad Saha who came second in both BSc and MSc examinations. Thereafter, Bose joined the newly established physics department of the university as a research scholar and lecturer (1917), then moved to the new University of Dacca (now Dhaka, in Bangladesh) as a Reader in 1921. Since he had not done a doctorate, Einstein’s recommendation helped him become a professor and head of the department there. He returned to Calcutta University in 1945. Science in Calcutta in the 1920s Eric Weiner in his best-selling book The Geography of Genius: A Search for the World’s Most Creative Places from Ancient Athens to Silicon Valley, writes how “Certain places, at certain times, produced a bumper crop of brilliant minds and good ideas,” and includes Calcutta (1840–1920) in the list of these places. After Bengal’s partition was annulled and when the capital was shifted to Delhi, the 1920s was the last decade perhaps, to have produced a flush of creativity in Calcutta. In the field of science, this period saw the emergence of C V Raman, S N Bose and Meghnad Saha, the likes of which has not happened in the country since then. Many factors must have contributed to such a flourishing environment—the stewardship of the university by Sir Ashutosh Mookerjee, a mathematician himself; the scientific climate having been created by the likes of J C Bose and P C Ray; and the urge for self-expression in a country reeling under colonial rule. Major breakthroughs like Saha’s equation of thermal ionisation (1920), Bose–Einstein (now, Bose) statistics (1924) and Raman effect (1928) have to be seen in this historical context. Bose, Einstein and their Collaborative Efforts Bose co-authored the first English translation of the original papers of Einstein and Hermann Minkowski as the Principle of Relativity (1919–20, with an introduction by P C Mahalanobis) with Saha, and published a few more. He wrote two papers in 1924 while working in Dacca. The most important one was titled “Planck’s Law and the Hypothesis of Light Quanta,” which was not published by the Philosophical Magazine of the Royal Society. But, Bose was so confident that he sent it with a personal, handwritten letter to Albert Einstein. It required the genius and insight of Einstein to appreciate the significance of this work. He translated it into German and sent it for publication in the prestigious journal Zeitschrift für Physik with a note that said, “In my opinion, Bose’s derivation of Planck formula constitutes an important advance. The method used here also yields the quantum theory of the ideal gas as I shall discuss elsewhere in more detail.” (Pais 1982). This became the basis of Bose statistics. In the area of quantum statistics, this “is one of two possible ways in which a collection of (non-interacting) indistinguishable particles may occupy a set of available discrete energy states,” (Encyclopaedia Britannica 1997) at thermodynamic equilibrium. The mathematical derivation by Bose was original, based on ISSN (Online) - 2349-8846 the concept of the “indistinguishability” of photons—the light quanta. Einstein translated Bose’s second paper also and got it published, but with a note of dissent. However, the noted physicist ECG Sudarshan (1994) wrote that “In these two papers done before the birth of quantum mechanics as we know today, Bose laid the foundations of a quantum theory of the electromagnetic field.” Bose’s third paper, sent to Einstein in 1925, remains unpublished and, sadly, it is untraceable. Particles following Bose statistics came to be known as bosons, as named by Paul Dirac (and particles following the other Fermi–Dirac statistics are known as fermions). Einstein developed Bose’s concept further, and extended it to monatomic ideal gases, and predicted what is known as the Bose–Einstein Condensation (BEC). BEC, a state of matter of a gas of bosons, diluted and cooled to near absolute zero temperature, is related to superfluidity and superconductivity. In an article titled “Bose- Einstein Condensation—SN Bose’s Legacy Lives On,” Wolfgang Ketterle of the Massachusetts Institute of Technology—one of the three winners of the Nobel Prize in 2001 for their experimental work on the subject—wrote that BEC “has changed the face of atomic physics. It is for atoms or matter waves what the laser is for photons: a macroscopically occupied quantum state. It was regarded as an elusive goal until it was discovered in 1995. Although BEC was immediately viewed as a major accomplishment, its impact has far exceeded expectations. Now more than 20 years later, there is no question that the field remains exciting. And maybe the best is yet to come.” (Ketterle 2019) During 1924–26, Bose visited Berlin and Paris for research work and interacted with Einstein and other leading physicists. Herman Mark of the Institute of Physics, Berlin remembered how, “… almost everything was done in German … Bose gave one of those seminars … That was based on his ideas about non-classical statistics of a system particularly of low temperature characteristics— and Nernst was sitting there, Einstein was there … and everyone interested in low temperature and statistics—and Planck was also there … Then Einstein said, ‘well I think this is one of the most worthwhile works of the last few years.’ He talked about it and asked a few questions and Bose answered the questions and then Nernst asked a few questions… In other words, it was a very sensational event on that day” (Mark 1974). According to Abraham Pais (1982), physicist and definitive biographer of Einstein, “The paper by Bose is the fourth and last of the revolutionary papers of the old quantum theory, the other three being by Planck, Einstein and Bohr.” Thus, Bose is rightly regarded as the originator of quantum statistics and an important figure behind quantum mechanics and quantum field theory. In the early 1950s, Bose also contributed a few important papers to unified field theory. ISSN (Online) - 2349-8846 Bose, the Nobel Prize and After Despite his pioneering contribution, Bose was not awarded a Nobel Prize. He was nominated a few times and leading scientists had felt that Bose had deserved one. Rajinder Singh (2017), physicist and historian of science, in the article, “The Ultimate Facts - SN Bose and the Missed Physics Nobel Prize,” records that the Nobel Committee asked its expert Oskar Klein in 1956 to evaluate his work. Taking note of Bose’s nomination for his work on quantum statistics and for his contribution to Einstein’s unified field theory later, Klein appreciated the former contribution as important but “not so distinguished as the work of other physicists” who won the prize. Furthermore, he commented about the latter that it “would even fit less to spirit for the Physics Nobel Prize,” since “It is on the mathematical contribution to Einstein’s long-standing attempt for a universal field theory—whose physical meaning as well as the whole Einsteinian program in any case, is still quite obscure.” As rightly observed by Singh, Bose’s case was not nominated in time and that the Nobel Committee had not been particularly in favour of theoretical physics. No wonder Einstein did not receive the prize, even for his most important work: the theory of relativity. Much later, Stephen Hawking also did not. Bose, however, never regretted the fact that he did not receive the Nobel Prize and was always content with the recognition that came his way. He was elected a Fellow of the Royal Society, and was awarded the Padma Vibhushan and was made a National Professor. He also presided over the Indian Science Congress, and after retirement from Calcutta University, served as the Vice-Chancellor for Visva-Bharati, Santiniketan.