What would you do if all the lights went out and they never came back on? That is a question that the new NBC series “Revolution” asks, but most people have no idea that a similar thing could happen in real life at any moment. A single gigantic electromagnetic pulse over the central United States could potentially fry most of the electronics from coast to coast if it was powerful enough. This could occur in a couple of different ways. If a powerful nuclear weapon was exploded at a high enough altitude, it could produce an electromagnetic pulse powerful enough to knock out electronics all over the…