THE EDGE OF PHYSICS tells the story of our quest to understand the universe, as seen through the eyes of a traveller. It's a journey to the ends of the Earth —Lake Baikal in Siberia, the Atacama Desert in the Chilean Andes, an abandoned mine in North America, Mauna Kea in Hawaii, the subterranean lair of the Large Hadron Collider near Geneva, the barren Karoo in South Africa, the frozen frontier of Antarctica and the Hanle Valley in the Indian Himalayas —in search of the telescopes, detectors and experiments that promise to shed light on the most pressing questions in physics and cosmology today.