Review of the Movie on the Mathemaɵcal Genius Ramanujan
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Asia Pacific Mathematics Newsletter ZĞǀŝĞǁŽĨƚŚĞDŽǀŝĞŽŶƚŚĞ DĂƚŚĞŵĂƟĐĂů'ĞŶŝƵƐZĂŵĂŶƵũĂŶ Krishnaswami Alladi The Man Who Knew Infinity Directed by Matt Brown Produced by Edward R. Pressman Film, Xeitgeist Entertainment Group, Animus Films, American Entertainment Investors, Kreo Films FZ Distributed by Warner Bros (UK), IFC Films (USA), 108 minutes, 2015 Jeremy Irons as G H Hardy, Dev Patel as Ramanujan The Man Who Knew Infinity is a film (referred Ramanujan fell ill in England and returned to as INFINITY from here on) about the remark- India in 1919. He died shortly thereafter in April able life story and pathbreaking work of Srini- 1920 at the young age of 32. But the vast number vasa Ramanujan, a self taught genius from of deep results spanning the fields of analysis, India, who communicated bewildering mathe- number theory and modular forms that he proved matical formulae in two letters in 1913 to the in his brief life, place him among the greatest esteemed G H Hardy of Cambridge University, mathematicians in history. The film concludes England, a towering figure in the mathematical with Hardy receiving the news about Ramanu- domains of analysis and number theory. The leg- jan’s demise in India and his emotional address to end is that the Hindu Goddess Namagiri came in the Royal Society when he describes Ramanujan’s Ramanujan’s dreams and gave him these formu- work as profoundly original. lae. Realising that Ramanujan was a genius on par The film does introduce dramatisation for with Euler and Jacobi, Hardy invited Ramanujan effect, thereby deviating from the true story to Cambridge where Ramanujan did pioneering in certain places, but the overall depiction of work by himself and with Hardy. The asymptotic Ramanujan’s life will move the audience to tears. series for the partition function they jointly ob- Ramanujan’s life story is so fascinating and in- tained [12] is a crowning achievement of their col- triguing, that dramatisation is really not needed laboration. The film is based on a book by Robert to get audiences excited. There is a good deal of Kanigel [13] under the same title — a book which mathematical discussion in the movie but in a gives a complete and accurate account of Ra- way that the audience will be inspired and not manujan’s life. Starting briefly with Ramanujan’s be put off by it. life and initial discoveries in India, the film deals First I will briefly describe Ramanujan’s life mostly with his life in England — his interactions and work so that my comments on the movie can with Hardy who wants “proofs” for the incredible be better understood. mathematical claims of Ramanujan, the resistance by some British mathematicians to recognise the Srinivasa Ramanujan (1887–1920) significance of Ramanujan’s work, Ramanujan’s insight in obtaining the asymptotic series for the Ramanujan was born on December 22, 1887, in his partition function, the difficulties he experienced maternal grandfather’s hometown Erode, in the in England during the tumultous period of World state of Tamil Nadu, in South India. But he grew War I, and the effort made by Hardy to get up in the nearby town of Kumbakonam where Ramanujan elected Fellow of the Royal Society his parents lived. Ramanujan and his family were (FRS) and Fellow of Trinity College (in that order), orthodox Iyengars — a subsect of the Brahmin which finally bore fruit after the first unsuccessful caste of the Hindu religion. Ramanujan’s father attempt of election to a Fellowship of Trinity. was an accountant to a cloth merchant and so December 2016, Volume 6 No 2 29 Asia Pacific Mathematics Newsletter his family was poor. His mother Komalatammal role in resolving this problem! One story is that was a strong willed woman. Ramanujan’s family Ramanujan’s mother had a dream in which she had a special veneration for Goddess Namagiri saw Ramanujan seated in an assembly of “white of the Temple of Namakkal near Kumbakonam. men” and being honoured, and the Goddess of Komalatammal was childless for many years, and Namakkal ordering her not to stand in the way so the family prayed to Namagiri to bless her with of her son’s recognition!! Was this a premoni- children, and shortly thereafter Ramanujan was tion of Ramanujan’s election to Fellowship of the born as her first child. Royal Society? In any case, when Komalatammal Ramanujan showed his unusual mathematical got up in the morning, she gave him permission talents early. As a boy, he would wake up in to sail to England. the middle of the night and write down math- Ramanujan was in England only for five years ematical formulae on a piece of slate that he kept (1914–1919), but in this brief period (i) he got a next to his bed, and would record these later in number of theorems he had discovered in India Notebooks that he maintained (photostat copies published in prestigious journals, (ii) made sev- of these Notebooks were later published [21]). eral new and fundamental discoveries by himself The legend is that the Goddess Namagiri would in England, and (iii) collaborated with Hardy come in his dreams and give him these formulae on two major projects, one of which being the which were startling even to professional mathe- asymptotic series for the partition function by the maticians. Ramanujan did not provide any proofs powerful circle method that they introduced for of his formulae in these Notebooks. the first time. But conditions in wartime England Although Ramanujan did well in school, ow- were tough, and especially difficult of Ramanujan ing to his excessive preoccupation with mathe- who as a strict vegetarian could not easily find matics, he did poorly in other subjects. So he food to suit his needs, and who did not know how dropped out of college and therefore did not to protect himself from the cold in the winters. possess a Bachelors degree. Unable to find indi- Consequently he often fell ill and was in and viduals in India who could evaluate his work, out of hospitals frequently. In spite of all this, Ramanujan wrote two letters to G H Hardy of his mathematical creativity and profundity were Cambridge University giving several samples of unbelievably high. So original were his contribu- spectacular formulae he had discovered, but with- tions, that Hardy felt he deserved to be elected out any hint of proofs or reasoning to justify Fellow of Trinity College and Fellow of the Royal such formulae. Hardy in consultation with his Society (FRS). But Hardy feared that owing to distinguished colleague J E Littlewood came to Ramanujan’s rapid decline in health, he will not the conclusion that Ramanujan was a true genius live long. Thus there was a real urgency in recog- ranking among the greatest mathematicians in nising Ramanujan for his outstanding contribu- history, and for sheer manipulative ability was tions. So he made a stupendous effort to suc- rivalled only by Euler and Jacobi. These formulae cessfully convince his distinguished colleagues to spanned several important domains in the realms confer these honours on Ramanujan, overcoming of number theory and analysis. Several formulae the initial resistance to the Fellowship of Trinity in the letters were profoundly original, but there proposal. Ramanujan returned to India in 1919 a were some that were well known, and others that very sick man. Just prior to that, Hardy wrote to were incorrect as stated. Hardy felt that Ramanu- Francis Dewsbury, Registrar of the University of jan’s time should not be wasted in rediscovery of Madras, saying that “he will return with a sci- past work owing to lack of formal training. So entific standing and reputation such as no Indian he invited Ramanujan to Cambridge so that his has enjoyed before” ([10], p. 200). Ramanujan died untutored genius could be given a proper sense in Madras in April 1920, but even in his last of direction. few months, he made pathbreaking discoveries, The orthodox Brahmins believed that it was and wrote one last letter to Hardy outlining his a sin to cross the oceans, and so even though discovery of the mock theta functions of orders 3, Ramanujan was willing to go to England, his 5, and 7. These are now considered to be among mother would not give him permission. The Ramanujan’s deepest contributions. Goddess of Namakkal seems to have played a In the final months of his life in Madras, India, 30 December 2016, Volume 6 No 2 Asia Pacific Mathematics Newsletter Ramanujan used to ask his wife Janaki Ammal (v) Elliptic and theta functions for loose sheets of paper to write down his new (vi) Modular forms and automorphic functions found results. After Ramanujan’s death, his wife (vii) Special functions and definite integrals (who did not even have a school education) had (viii) Continued fractions the good sense to collect these loose sheets and (ix) Diophantine equations deliver them to the University of Madras from (x) Irrationality and transcendence where they were sent to Hardy. Eventually these (xi) Fourier analysis sheets came to the possession of G N Watson (xii) Lie algebras in Birmingham, the world’s premier authority in (xiii) Statistical mechanics and conformal field the field of special functions. Watson analysed theory in physics the results on mock theta functions of order 3 in (xiv) Computer science and computer algebra Ramanujan’s last letter to Hardy, and presented This list is not complete and is definitely grow- his findings as his Retiring Presidential Address ing. The Ramanujan Journal launched in 1997 to the London Mathematical Society. But there by Kluwer and now published by Springer, is was much more on these loose sheets than what devoted to all areas of mathematics influenced was summarised by Ramanujan in his letter.