Correspondent Scott Pelley takes a look at Aaron Alexis, who hunted employees in a U.S. Naval office in 2013, and how he was granted a U.S. government security clearance. Correspondent Lesley Stahl visits the Large Hadron Collider, a machine hundreds of feet beneath Switzerland and France, that smashes subatomic particles together. And correspondent Charlie Rose reports on "Hamilton", a Broadway musical about the life and times of founding father Alexander Hamilton and his contemporaries.