The USS  Johnston - photo courtesy of Caladan Oceanic This week, in "science is cool," the main section of a ship that sunk 77 years ago during the Battle of Leyte Gulf in World War II has been discovered off of the Philippine coast. Resting over 4 miles beneath the surface, the USS  Johnston  is the deepest shipwreck ever to be investigated. The 376-foot long  Fletcher- class destroyer was discovered in the Philippine Trench near Samar Island at a depth of 21,...