Fourteen mountain peaks on Earth stand taller than 8,000 meters (26,247 feet). Pictured here is the tallest of these “eight-thousanders” -- Mount Everest, the standard to which all other mountains are compared. The Nepalese name for the mountain is Sagarmatha: “mother of the universe.” When climbers reach the top of Mount Everest, they are perched on softer sedimentary rock formed by the skeletons of creatures that lived in a warm ocean off the northern coast of India tens of millions of years ago. Meanwhile, glaciers have chiseled Mount Everest’s summit into a huge, triangular pyramid, defined by three faces and three ridges that extend to the northeast, southeast, and northwest. The southeastern ridge is the most widely used climbing route. It is the one that Edmund Hillary and Tenzing Norgay followed in May 1953 when they became the first climbers to reach the summit and return safely. Despite its reputation as an extremely dangerous mountain, commercial guiding has done much to ta...