THE life of the imagination is difficult to capture, let alone to contain, onscreen. For that reason, movies about such original thinkers as famous writers and artists — or, as in The Man Who Knew Infinity, the pioneering mathematician Srinivasa Ramanujan — suffer from an inherent difficulty. How do you show, in ways that are at least vaguely cinematic, the stroke of genius?

Dev Patel plays Ramanujan, a self-taught mathematical prodigy from India who died tragically at age 32 after doing groundbreaking work at Cambridge University in the early years of the 20th century. For simplicity’s sake, the film focuses on only one aspect of Ramanujan’s work: his pioneering exploration of number theory, particularly as related to partitions.

The number 4, for instance, can be expressed as the sum of five — and only five — “partitions” of whole numbers: 1+1+1+1; 1+1+2; 1+3; 2+2; and 4. As a number grows larger, approaching infinity, could there be a formula, Ramanujan wondered, that would calculate the number of its partitions?

He thought he had found one. All he had to do was prove it to a sceptical, Anglo-centric academic community.

This is maths at its purest — maths for maths’ sake — and it’s heady, if hardly cinematic, stuff. We watch Ramanujan shuffle back and forth between his digs at Cambridge and the office of his mentor, Professor G.H. Hardy (Jeremy Irons), who suspects his protégé is right but not rigorous. Hardy pushes him to be more diligent in his proofs. Ramanujan, meanwhile, equates his grasp of number theory to a religious experience — to a glimpse of God, in short — as something that comes to him intuitively rather than through cold, hard calculation.

“Every single positive integer is one of his friends,” Hardy’s colleague Littlewood (Toby Jones) aptly observes after Ramanujan notices that the number of his taxi, 1729, happens to be “the smallest number expressible as the sum of two cubes in two different ways”. (Such anomalies have today come to be called “taxicab numbers” after Ramanujan.)

Of course, our hero is also quite ill with tuberculosis through all of this, so the movie benefits from the poignancy of a brilliant life about to be extinguished. Other sad sub-themes — anti-Indian racism, Ramanujan’s pining for his wife back in Madras — add little to the film except clichéd sentimentality.

Based on Robert Kanigel’s well-received 1991 biography of Ramanujan, The Man Who Knew Infinity tells a great story. It’s just that it’s a little too by-the-book to make anything other than a so-so movie.

By arrangement with The Washington Post

Published in Dawn, May 8th, 2016