Why did pirates covet maps more than gold? Does Mars sometimes slip into reverse gear? Can trees reveal secrets of the past? There are millions of facts that we know about the world-that the earth is round, that birds migrate and that dinosaurs once roamed the planet. But how do we know what we know? Regaling us with tales of remarkable men and women who didn't rest until they got the answers they sought, Shruthi Rao chronicles the stories behind the discoveries and inventions we take for granted today. This book, in fifty marvellous accounts, tells us of the sense of mystery and wonder that propel scientists to find solutions to the puzzling problems of the world around us.