NOW A MAJOR MOTION PICTURE STARRING JEREMY IRONS AND DEV PATEL! A moving and enlightening look at the unbelievable true story of how gifted prodigy Ramanujan stunned the scholars of Cambridge University and revolutionized mathematics. In 1913, a young unschooled Indian clerk wrote a letter to G H Hardy, begging the preeminent English mathematician's opinion on several ideas he had about numbers. Realizing the letter was the work of a genius, Hardy arranged for Srinivasa Ramanujan to come to England. Thus began one of the most improbable and productive collaborations ever chronicled. With a passion for rich and evocative detail, Robert Kanigel takes us from the temples and slums of Madras to the courts and chapels of Cambridge University, where the devout Hindu Ramanujan, "the Prince of Intuition," tested his brilliant theories alongside the sophisticated and eccentric Hardy, "the Apostle of Proof." In time, Ramanujan's creative intensity took its toll: he died at the age of thirty-two, but left behind a magical and inspired legacy that is still being plumbed for its secrets today. Robert Kanigel is the author of The Man Who Knew Infinity , Eyes on the Street , The One Best Way , Hearing Homer’s Song , and six other nonfiction books—in biography, history, history of science, and memoir. He has been a finalist for the National Book Critics Circle Award and the Los Angeles Times Book Prize, and a recipient of a National Endowment for the Humanities Public Scholar award as well as a Guggenheim fellowship. He spent earlier lives as a mechanical engineer, a professor of science writing at MIT, and a freelance writer of magazine articles, essays, and reviews. An avid cyclist and amateur mosaicist, he lives in Baltimore. The Man Who Knew Infinity CHAPTER ONE In the Temple’s Coolness [1887 to 1903] 1. DAKSHIN GANGE He heard it all his life—the slow, measured thwap . . . thwap . . . thwap . . . of wet clothes being pounded clean on rocks jutting up from the waters of the Cauvery River. Born almost within sight of the river, Ramanujan heard it even as an infant. Growing up, he heard it as he fetched water from the Cauvery, or bathed in it, or played on its sandy banks after school. Later, back in India after years abroad, fevered, sick, and close to death, he would hear that rhythmic slapping sound once more. The Cauvery was a familiar, recurring constant of Ramanujan’s life. At some places along its length, palm trees, their trunks heavy with fruit, leaned over the river at rakish angles. At others, leafy trees formed a canopy of green over it, their gnarled, knotted roots snaking along the riverbank. During the monsoon, its waters might rise ten, fifteen, twenty feet, sometimes drowning cattle allowed to graze too long beside it. Come the dry season, the torrent became a memory, the riverbanks wide sandy beaches, and the Cauvery itself but a feeble trickle tracing the deepest channels of the riverbed. But always it was there. Drawing its waters from the Coorg Mountains five hundred miles to the west, branching and rebranching across the peninsula, its flow channeled by dams and canals some of which went back fifteen hundred years, the Cauvery painted the surrounding countryside an intense, unforgettable green. And that single fact, more than any other, made Ramanujan’s world what it was. Kumbakonam, his hometown, flanked by the Cauvery and one of its tributaries, lay in the heartland of staunchly traditional South India, 160 miles south of Madras, in the district then known as Tanjore. Half the district’s thirty-seven hundred square miles, an area the size of the state of Delaware, was watered directly by the river, which fell gently, three feet per mile, to the sea, spreading its rich alluvial soil across the delta. The Cauvery conferred almost unalloyed blessing. Even back in 1853, when it flooded, covering the delta with water and causing immense damage, few lives were lost. More typically, the great river made the surrounding land immune to year-to-year variation in the monsoon, upon whose caprices most of the rest of India hung. In 1877, in the wake of two straight years of failed monsoons, South India had been visited by drought, leaving thousands dead. But Tanjore District, nourished by the unfailing Cauvery, had been scarcely touched; indeed, the rise in grain prices accompanying the famine had brought the delta unprecedented prosperity. No wonder that the Cauvery, like the Ganges a thousand miles north, was one of India’s sacred rivers. India’s legendary puranas told of a mortal known as Kavera-muni who adopted one of Brahma’s daughters. In filial devotion to him, she turned herself into a river whose water would purify from all sin. Even the holy Ganges, it was said, periodically joined the Cauvery through some hidden underground link, so as to purge itself of pollution borne of sinners bathing in its waters. Dakshin Gange, the Cauvery was called—the Ganges of the