Andrew Robinson marvels afresh at the self-taught mathematical genius in a new biopic.

The Man Who Knew Infinity

Written and directed by Matthew Brown. Edward R. Pressman Films/Animus Films: 2016.

The story of the Indian mathematician Srinivasa Ramanujan (1887–1920) is improbable. Self-taught, he made many seminal discoveries in number theory and power series — most famously concerning the partition of numbers into a sum of smaller integers — that continue to fascinate mathematicians and intrigue physicists studying black holes and quantum gravity. In The Man Who Knew Infinity, director Matthew Brown dramatizes the purest of mathematics for a general audience, and explores the strange personal life of Ramanujan, who died at 32, at the height of his powers, probably from tuberculosis. Based on the compelling biography of the same name by Robert Kanigel (Scribner, 1991), the film took more than ten years to create. It is worth the wait. Dev Patel stars as Srinivasa Ramanujan in The Man Who Knew Infinity. Credit: Warner Bros. Pictures

Ramanujan's career was 'made' by British mathematician G. H. Hardy, a fellow of Trinity College, Cambridge. In 1913, while working as an accounts clerk in what is now Chennai, Ramanujan sent Hardy startling, entirely unproven, theorems out of the blue. “They must be true,” wrote Hardy, “because, if they were not true, no one would have the imagination to invent them.” Hardy lured Ramanujan to Cambridge, even though foreign travel was considered an offence against Hindu caste purity. They collaborated intensively throughout the First World War. Ramanujan had no university degree, but in 1918, Hardy ensured that he was elected a fellow of the Royal Society — the first Indian to receive the honour after it was restricted to scientists — and of Trinity College. They encountered considerable opposition, some of it racially motivated.

Hardy's relationship with Ramanujan holds the film together. Convincing performances by Jeremy Irons as Hardy and Dev Patel as Ramanujan were carefully refined by the film's Japanese–American mathematics adviser, Ken Ono, whose academic career has been dedicated to exploring Ramanujan's theorems. Irons and Patel animate both the consuming passion for mathematics shared by the two, and their astonishing lack of personal intimacy; Hardy, for instance, had only a faint idea of Ramanujan's growing depression, which led to a suicide attempt on the London Underground. Irons, however brilliant, is a generation older than Hardy was in 1914, and Patel is taller and nattier than the more corpulent Ramanujan, who was ill at ease in Western dress.

Much of the action — and mathematics — takes place in the handsome precincts of Trinity College, which opened its doors to a feature film for the first time. In Hardy's room and the quadrangles, Ramanujan persistently resists Hardy's demands for proofs of his tantalizing theorems. An excited Ramanujan infuriates a lecturer by failing to take notes and then quickly chalking a correct formula: a very special integral due to Carl Friedrich Gauss, which Ramanujan knew through a method of his own devising. And in an evocative scene in Trinity's Wren Library, the famously atheistic Hardy tells his Indian protégé that the greatest honour “is to have a legacy at Wren once we are gone. In this very library are the Epistles of St Paul, the poems of Milton, Morgan's Bible and, in my estimation as a man of numbers, the pièce de résistance, Newton's Principia Mathematica.” Ramanujan's 'lost notebook' — which contains important mathematical discoveries made in India in 1919–20 and was neglected until 1976 — is, fittingly, in the Wren Library.

Scenes in India are no less ravishing. We see Ramanujan in flowing Indian clothes with Brahminical caste marks, chalking endless equations on the floors of a highly decorated Hindu temple. His dominating mother Komalatammal and wife Janaki provide a glimpse of domestic life. Indian and British colonial figures come and go (with a cameo by Ramanujan admirer Stephen Fry). But the film struggles to shed light on the origins of Ramanujan's prodigious gift. Biographers have had the same problem with Gauss and many other mathematicians. As India's great film director Satyajit Ray put it: “This whole business of creation, of the ideas that come in a flash, cannot be explained by science.”

Hardy, too, was dazzled and puzzled. On a 0–100 scale of natural mathematical ability, he gave himself a score of 25 and Trinity colleague John Littlewood (a fellow supporter of Ramanujan) 30, compared with 80 for influential mathematician David Hilbert and 100 for Ramanujan. “The limitations of his knowledge were as startling as its profundity,” Hardy wrote after Ramanujan's death. “All his results, new or old, right or wrong, had been arrived at by a process of mingled argument, intuition and induction, of which he was entirely unable to give any coherent account.”

Ramanujan has inspired many. Christopher Sykes's pioneering UK television documentary, Letters from an Indian Clerk, was screened in 1987. The play A Disappearing Number, devised by Théâtre de Complicité, was produced in Britain in 2007 (see Nature 449, 25–26; 2007). A biographical novel by David Leavitt, The Indian Clerk (Bloomsbury), was published in 2007.

Now, the film has spawned an intriguing, moving autobiography by Ono, My Search for Ramanujan (Springer, 2016), written with science writer Amir Aczel, who died before publication. Ono interweaves Ramanujan's life and work with his own fight to become a mathematician — including a suicide attempt — in the shadow of his distinguished mathematician father, Takashi Ono. After years of estrangement, the Onos realized that they were united by admiration and affection for the university drop-out Ramanujan. Here is yet another example of how this enigmatic Indian's unique achievements continue to reverberate nearly a century after his death.

Author information Affiliations Andrew Robinson is the author of Genius and Satyajit Ray: The Inner Eye. Andrew Robinson Authors Andrew Robinson View author publications You can also search for this author in PubMed Google Scholar Corresponding author Correspondence to Andrew Robinson.

Rights and permissions Reprints and Permissions

About this article Cite this article Robinson, A. Film: In search of Ramanujan. Nature 531, 576–577 (2016). https://doi.org/10.1038/531576a Download citation Published: 30 March 2016

Issue Date: 31 March 2016

DOI : https://doi.org/10.1038/531576a