In “Countdown,” the science journalist Sarah ... from the longbow to the battleship. The nuclear bomb is an exception so far, but who knows? For now, nukes are emphatically present and ...

Although Jeppson is an expert, as Parsons knows, there is nothing quite like arming a nuclear bomb at 5,000 ft. Jeppson works in a space little wider than a foot. Minutes later, his work is ...