Fry uncovers Indian maths genius's role in digital age

Srinavasa Ramanujan, whose ideas underpin the internet revolution, was a poor Indian college dropout who nearly starved to death before he ended up at Cambridge in the early 1900s.

Now acknowledged as a mathematical genius, Ramanujan, who died aged 33, is known as the most esoteric mathematical genius of the 20th century.

His contribution to the digital age is to be finally recognised in film now that the writer and TV presenter Stephen Fry and India's leading writer-director, Dev Benegal, have decided to collaborate on a feature film on his life.

Born in rural India, Ramanujan's life was extraordinary. By 13 he had mastered advanced trigonometry, and by 14 his teachers would stand dumbstruck in admiration at his mathematical prowess. Nicknamed "the man who knew infinity", Ramanujan excelled in number theory and modular functions. He also made significant contributions to the development of partition functions and summation formulas involving constants such as pi.

But as a schoolboy he could not concentrate on other subjects besides maths and flunked his secondary school exams. He was poor and was often pushed to the point of starvation.

Working as a clerk in the port of Madras, he wrote letters to Cambridge mathematicians in 1912 and early 1913. On his third attempt he found a sympathetic G H Hardy, who was keen to help the poor and disadvantaged over the "confident, booming, imperialist bourgeois English".

Initially Hardy thought Ramanujan's 10-page letter, containing more than 100 statements of mathematical theorems, was a prank. He later realised that the "results must be true because, if they were not true, no one would have the imagination to invent them".

Hardy, one of the pre-eminent mathematicians of the day, said that they were so advanced that "not one [theorem] could have been set in the most advanced mathematical examination in the world". Hardy said of the theorems that "many of them defeated me completely; I had never seen anything in the least like them before".

He later recalled of Ramanujan: "I remember once going to see [him] when he was lying ill at Putney. I had ridden in taxi cab number 1729 and remarked that the number seemed to me rather a dull one, and that I hoped it was not an unfavourable omen. 'No,' he replied, 'it is a very interesting number; it is the smallest number expressible as the sum of two cubes in two different ways.'"

Stephen Fry came to learn about Ramanujan and G H Hardy while at Cambridge. The director Dev Benegal's passion to tell this story dates back some 20 years, to when he travelled the entire length of the river Kaveri in a small round boat made of dried palm leaves and came past the towns of Erode and Kumbakonam, where Ramanujan was born and studied. The story has haunted him for years, but never found any interest among the Indian film community. A chance encounter in 2005 led to Fry and Benegal discovering their shared passion.

Benegal told the BBC: "What is amazing is that two people from two completely different backgrounds found a common language in the world of numbers and maths.

"For me, Ramanujan's work and ideas are the DNA of what powers digital technology today. When your automated teller machines divide and arrange your money before coughing it up, they are all using Ramanujan's partition theory."