I saw the Ramanujan Movie and I loved it. “The Man Who Knew Infinity,” came out a few weeks ago, starring Dev Patel as Srinivasa Ramanujan and Jeremy Irons as G.H. Hardy, it was a beautifully told story of what Hardy would later call, “the one romantic incident in my life.” The story is a truly captivating one, and the mathematics in play — partition functions, mock modular forms, and Ramanujan’s famous identities — fall secondary to the relationship between the two main characters.
As a mathematician, I tend to watch mathematical movies with one eye shut for fear of the gross misrepresentations that will befall my field and my fellow practitioners. I felt like this movie did a splendid job. It was light on the details, but gave just enough information on the partition function so that a lay audience could grasp the problem. But more importantly, thanks in large part to the consulting work of Ken Ono, the scenes were they were actually doing math felt so real to me. The way they worked together, the way they talked to each other and interacted, and even the montages of Ramanujan working alone in his room felt so familiar. And I’m so glad that for once a math movie decided to forgo that strange mathematician-writing-equations-on-a-piece-of-glass trop. Ramanujan used pen and chalk. Just like in real life.
Ramanujan, who never had any formal training in mathematics, arrived at Trinity with a notebook full of equations and identities without a single proof. To him, the proofs were trivial, since everything just seemed obvious to him. To Hardy, the results might as well not exist if they couldn’t be substantiated with proof. In one scene, Hardy lays into Ramanujan, telling him that they cannot proceed unless he begins to formalize rigorous proofs of his ideas. Ramanujan balks. I loved this scene, because this exact struggle happens on a smaller scale in my proof writing classes all the time. A student makes (what to him is) an obvious claim and I say, “prove it.” Then he said, “but it’s obvious.” And I say, “tell me why.” And he gets so mad. Eventually the student understands what I mean, but usually not without a mini revolt. I love to imagine that for at least a few moments Hardy and Ramanujan felt the same strains of the teaching-student dynamic that we all do.
As a side note, it was absolutely thrilling to sit in a movie theater full of people who all came out to see this movie about one of my favorite people. I know, it’s not about me. But wow, if I didn’t just want to tap the people in front of me on the shoulder and ask, “Isn’t Ramanujan just the greatest. Which identity do you love the most??”