As global tensions continue to build, science fiction-fueled fears of a devastating electromagnetic pulse attack have begun to surface. Some speculate that North Korea could detonate a high-altitude nuclear weapon in space, setting off an EMP that would knock out electrical systems down below, with catastrophic results. But, experts are not convinced that this is how the scenario would pan out. According to nuclear non-proliferation expert Jeffrey Lewis, tests of such devices in the past were largely anticlimactic, and failed to produce the widespread electrical disruption that's been predicted over the years. The expert points to a test conducted by the US in 1962 known as'Starfish Prime.' EMP, or electromagnetic pulse weapons use missiles equipped with an electromagnetic pulse cannon.