Srinivasa Ramanujan

Srinivasa Ramanujan was born in 1887 in Erode, Tamil Nadu, and grew up in Kumbakonam, where his father was a clerk in a cloth shop. At 15 he borrowed a book that listed some 5,000 mathematical results with almost no proofs, and set about proving them himself. It was a strange way to learn, and it shaped him: for the rest of his life he produced results by intuition and struggled to explain how.

He won a scholarship to college and lost it within a year because he failed everything except mathematics. A second college went the same way. For years he lived in poverty, filling notebooks and sometimes going without food, until in 1912 he found a job as a clerk at the Madras Port Trust. His employers noticed what he was doing in the margins.

In January 1913 he wrote to G. H. Hardy at Cambridge, enclosing nine pages of theorems. Hardy, at first, suspected a fraud. Then he decided the results had to be true, because no one could have had the imagination to invent them. He arranged for Ramanujan to come to England in 1914.

The five years in Cambridge were the most productive of his life and very hard. He was a strict vegetarian in wartime, cooking for himself, cold and often ill. In 1918 he was elected a Fellow of the Royal Society, one of the youngest ever. The following year, seriously ill, he sailed home. He died in April 1920, aged 32. A notebook of his last work, found in 1976, is still yielding new mathematics.