Traversing Iceland by foot, Mongolia by horseback, Arabia by camel and the Blue Nile Gorge by raft; Bruce Kirby’s journeys span 80 countries around the world. In his new book “Blue Sky Kingdom,” we follow Kirkby and his family as they hop on a freighter and make a remarkable three-month journey from Canada to the Himalayas. We asked the writer, photographer, and now author what prompted his adventure halfway around the globe.