Charged Particle Beams
A charged particle beam (CPB) is a directed-energy weapon that fires pulses of charged particles to heat and potentially explode a target. Theoretically, such a weapon could reach a target almost instantly and at enormous range, delivering lethal doses of energy in seconds or less. However, the technical challenges involved in building a beam like this -- especially one capable of firing in the atmosphere -- remain daunting [source: Roberds].
Amid the gathering clouds of World War II, Tesla announced that he had conceived a new "peace beam" weapon capable of ending war forever. He saw his device, which we now know as a charged particle beam, as a kind of "Chinese wall," an anti-war device that would safeguard national borders. The papers took a different view: "TESLA, AT 78, BARES NEW 'DEATH BEAM'" blared The New York Times' front page on July 11, 1934.
CPBs were made famous by Reagan's Strategic Defense Initiative, or Star Wars, program, but the U.S. Defense Advanced Research Projects Agency (DARPA) was investigating them as early as 1958 [source: Roberds].