EMP

An electromagnetic pulse generator (EMP) is an anti-electronics weapon that mimics the intense EM radiation emitted by a nuclear explosion. The resulting EM field couples with nearby electronics systems, producing massive, damaging electrical currents. An old EMP device was being transported to Caprica from the Galactica on Colonial Heavy 798 (later Colonial One), presumably to place in a planetside museum or school as a historical artifact (Mini-Series). As the destruction of the ship by a Cylon raid seems imminent, Lee Adama activates the weapon, giving the appearance that the Colonial One had been destroyed by a nuclear blast. This attempt appears to be successful, as the Cylons cut off the assault and Galactica's radar confirms the ship as destroyed. The Colonial One's electronic systems seem to be fully functional, however (The actual science behind this particular EMP is never actually explained, much like the mysterious artifical gravity).