DANGER FROM ABOVE
What is EMP? When a nuclear device detonates at a very high altitude it releases energy in the form of gamma rays, which collide with air molecules to produce certain electrons. These electrons then interact with the Earth's magnetic field to produce an intense electromagnetic pulse that flashes down to the Earth's surface at the speed of light. The pulse interacts with metallic conductors, such as aircraft, ships, and power and communications lines, damaging voltage and currents in unprotected electronic components. One blast at a 250-mile altitude, according to Gary L. Smith, director of The Johns Hopkins University's Applied Physics Laboratory, could produce an EMP that would blanket the entire continental United States. EMP is not sensed by persons and does not harm the human body.