 Which theory didn't they rule out for how Superior went missing?
Radio messages stated simply that Superior had seceded from Earth. The state police converged on the former site of Superior from several directions. Communicating by radiophone across the vast pit, they confirmed that the town undoubtedly was missing. A National Guard officer volunteered to take a jeep down into the pit, having found a spot that seemed navigable. The Pentagon and the Atomic Energy Commission denied that they had been conducting secret experiments. The object loomed out of a cloudbank at twelve thousand feet and Studley changed course to avoid it. A few minutes later he had relayed a message from Superior, formerly of Ohio, addressed to whom it might concern: It said that Superior had seceded from Earth. One other radio message came from Superior, now airborne, on that first day.
 magnetized levitation
 secret government experiments  explosives  factory explosion  magnetized levitation