Those of you who are familiar with Arthur C. Clarke's 1955 novel Earthlight may recognize a new weapon from DARPA dubbed the Magneto Hydrodynamic Explosive Munition (MAHEM). In the novel, a commander unleashes "The Stiletto"—a weapon consisting of a jet of molten metal hurled through space by an electro-magnet. The MAHEM concept works in much the same way, using a magnetic field to propel a chunk of molten metal that will morph into an aerodynamic slug in flight.
Other weapons, like the High-Explosive Anti-Tank (HEAT) round have utilized similar technology for years using an explosive charge instead of a magnetic field as the propellant. According to DARPA "MAHEM could be packaged into a missile, projectile or other platform and delivered close to target for final engagement and kill"—and it would undoubtedly whup some serious ass. Whether the 53 year old idea actually comes to fruition remains to be seen. [DARPA via NewScientist]