The Man Who Knew Infinity

Out Now On-Demand

Great knowledge comes from the humblest of origins.

Dev Patel (The Best Exotic Marigold Hotel) is Srinivasa Ramanujan in this historical biopic, the mathematical genius who grew up in a poor region of India and gained admittance to Cambridge University during the First World War. Jeremy Irons plays his professor and mentor G.H. Hardy. Co-stars Toby Jones and Stephen Fry.


Directed by

Written by

  • Matt Brown
  • (based on the biography by Robert Kanigel)

Drama, True Story & Biography, Historical


Rating: PG


If you can recall the frustration of getting the right answers in a school maths tests but being marked down for not explaining how you got there, you’ll relate to this film, for it’s essentially Show Your Working: The Movie. Sure, it’s not an eye-grabbing title (especially for those with mathlexia), but it does succinctly describe the main challenge faced by real-life mathematic genius Srinivasa Ramanujan (Dev Patel) and collaborating Cambridge University professor G.H. Hardy (Jeremy Irons).

The film is appropriately by-the-numbers, for the true story probably doesn’t lend itself to Oscar-worthy grandeur. The humble Ramanujan’s love for mathematical formations is at odds with Hardy’s love for barely anything. Hardy needs to teach Ramanujan how to provide proof to his astonishing discoveries if they are to be published, but doesn’t relate to Ramanujan’s affinity for, well, infinity. So when Hardy delivers cold criticism, it hits Ramanujan emotionally, and Patel and Irons work that intriguing dynamic wonderfully.

It’s a pleasant depiction of a mightily significant partnership in the field of mathematics (Ramanujan’s discoveries are vital to today’s understandings of the universe). It’s a shame some areas of the film feel disingenuous, like how every moment of racism skips subtlety and dials it straight up to 100. There’s also an exchange where Hardy suggests he’s not expected to speak Tamil, to where Ramanujan replies “Yet you expect me to speak English.” It’s a good burn, though it also draws attention to the film's depiction of everyone in India speaking English anyway.

Time Out New York


Polite, earnest stuff, but it never quite adds up to much.

Empire (UK)


Well intentioned and played, this shows flashes of what could have been, but is ultimately let down by its timidity towards the maths...

Telegraph (UK)


Irons’s Hardy steals this film away from its ostensible hero, in part because pulling the shutters down makes him that much harder to know.

Hollywood Reporter


Highly engaging performances by Dev Patel in the lead role and Jeremy Irons as his curmudgeonly mentor gradually warm up the Cambridge story...

Variety (USA)


The arguments between Ramanujan and Hardy form easily the most absorbing aspect of The Man Who Knew Infinity...

Guardian (UK)


At the end, it looks like a treacly, albeit high-minded Sunday afternoon drama serial.

Sydney Morning Herald


Predictable but poignant.

New York Times


Mr. Irons handily hits the emotional beats, as does Mr. Patel, as Ramanujan confronts incipient tuberculosis. (Christina Kuntz)


Touching, yes, and also informative, but it doesn't really add up to much in the end.

A sliver of Indian culture meets British culture thru maths

Reasonably interesting movie on an Indian man who saw numbers and their meanings in his mind and wanted to tell the world, but was hemmed in by need to prove it, compounded by British culture at war time. I feel it probably didn't portray how huge the gaps actually were between the poor genius Ramanujan and the British arrogance and cultural barriers, tho I guess that wasn't the intention of the movie.

Recommend it

If you enjoyed The Theory of Everything, you will probably enjoy this. Masterful performance from Jeremy Irons.