To Trinity and beyond! On the set of The Man Who Knew Infinity

Image for To Trinity and beyond! On the set of The Man Who Knew Infinity

Dev Patel is having a tough time in Cambridge. Yesterday The Man Who Knew Infinity required him to fall into the River Cam in front of a throng of gawping tourists for a scene that won’t even make the final cut. Now he’s been stung by a rogue Trinity College wasp. He rubs his arm gingerly. The timing couldn’t have been much worse. “I was just in the middle of meeting the actress who’s playing my wife for the first time,” he confides with a grin. “I’m trying to be all suave and Sean Connery-esque and it freaked the shit out of me!”

Upstaged by an insect maybe, but the puppyish Patel doesn’t let it dampen his mood for long. He’s the star of the show after all, playing a man who, as the title promises, knows an awful lot about an awful lot. His character, Srinivasa Ramanujan, travels from Madras in 1914 to this austere seat of learning to hone his uncanny but raw maths skills. Revered by mathematicians to this day but still a mostly unheralded figure, Ramanujan will soon be a big-screen maths whizz to rival A Beautiful Mind’s Jonathan Nash and Stephen Hawking in The Theory Of Everything (filmed at nearby St John’s College). Good Will Punting, you could call it.

It's a kind of bromance. Ramanujan and Hardy are chalk and cheese but they’re tied together.

Today, the movie’s central mystery – how he came by all this mathematical genius – is unfolding in Trinity Great Court. As with most film sets, it’s unfolding fairly serenely. Across the quad’s immaculately manicured lawn sits Jeremy Irons, Patel's co-star and Ramanujan’s doughty, demanding mentor G. H. Hardy in the story. He downs his New York Times crossword and, employing a suitably period-looking contraption, rolls himself a cigarette. “Terrible, terrible,” he shudders at an enquiry over his own maths skills. “I struggle with long division and Pi has always eluded me.” Empire, C in GCSE maths fresh in the mind, nods in sympathy.

Dev-Patel-Jeremy-IronsGown, baby, gown: Dev Patel and Jeremy Irons patrol Trinity College.

Fortunately, help has been at hand. While some movies have historical consultants, some have military advisors - don’t tell Patel but The Swarm even had a bee advisor - The Man Who Knew Infinity has its own maths teacher. “We had one of the world’s leading mathematicians for a couple of weeks,” Irons recalls, “and I was able to bend his ear, so I sort of know what I’m saying”. But what of those complex equations Hardy will no-doubt be required to scrawl on blackboards? “Cheat, cheat, cheat,” he grins. “We’re going to have someone read to me through an earpiece.”

Whatever I got in GCSE maths, it had a minus at the end of it.

Numbers might not run in the family for Irons, the son of a chartered accountant, but then this isn’t a film that requires prior knowledge of partitions or quadratic forms. Instead, the focus falls on the odd-couple relationship between Hardy and his young Indian pupil. It's a surrogate father-son dynamic in which the stern, austere Hardy and the instinctive, homesick Ramanujan clash, make up and clash again against the backdrop of Great War-era Cambridge.

“It's a kind of bromance,” says Patel, now relocated to the actors' green room in a shady corner of the quad. He relates it to The King’s Speech. “I don’t want to compare but it’s like that Geoffrey Rush and Colin Firth thing: they’re chalk and cheese but they’re tied together.” The script’s appeal was personal for the Slumdog star. “I really related to the fish-out-water story. The adversity he had to go through to achieve greatness is quite inspiring, really.”

The-Man-Who-Knew-InfinityDev Patel chews the fat with writer/director Matt Brown.

Here at Trinity, the Indian wizard remains an inspiration. Patel was humbled to see a plaque commemorating his character on the college wall. It might explain why this film succeeded where Chariots Of Fire (among others) fell short, and persuaded Trinity to open its doors to a film crew. “We lucked out,” he says. “I think they’re just proud of Ramanujan and his legacy, and Jeremy’s involvement too."

So if Irons is a maths duffer, how does Patel shape up? “I’m one step further on the dumb scale,” he laughs, sheepishly confessing that his dad is also an accountant. “That just made my GCSE result even more embarrassing,” he laughs. “Whatever I got in it, it had a minus at the end of it.”

The Man Who Knew Infinity is in cinemas on April 8. Read Empire’s review here.