Keeping Climbers Alive with Physics

Tommy Caldwell (second from left) and Kevin Jorgeson (fourth from left) celebrating their climb of Dawn Wall yesterday afternoon. Credit: Peter Stevens via flickr Yesterday afternoon in Yosemite National Park, rock climbers Tommy Caldwell and Kevin Jorgeson made history by completing the first free ascent of Dawn Wall, reputed to be the hardest climb in the world. Caldwell and Jorgeson owe their success to their remarkable perseverance, strength, technique, and also to three key bits of physics...