Most elements in the actinide series were created artificially; only thorium and uranium are found in nature. Segments in this program include Exploring the Actinide Series (properties of the actinides); Uranium: Stealth Boomer (the use of uranium to power nuclear weapons and reactors); Americium: Smoke Signals (why americium is used in smoke detectors); Californium: Cancer Killer (why californium holds great promise in the field of cancer treatment); and The Bomb: End of Innocence (the development of the atomic bomb). A Discovery Channel Production. (55 minutes)