FOR centuries, sailors used sextants to plot their location on the trackless sea, lining up stars in the sky to find their own place on Earth. Peter Hogan is a sailor, too — a midshipman at the U.S. Naval Academy in Annapolis, surrounded by some of the most advanced geolocation technology ever devised. But even though GPS can pinpoint Hogan and his shipmates on the most remote oceans on the planet, the Navy is once again teaching them the ancient art of celestial navigation.
