1 Clinical Psychologist: Doctorate Degree in Psychology (4 to 7 years of graduate school) 2  Industrial-Organizational Psychologist: Master's Degree (2 to 3 years of graduate school)  Forensic Psychologist: Master's Degree (2 to 3 years of graduate school); a doctoral degree is recommended.
Submarine Propulsion Systems. During World War II, most American submarines were powered by diesel-electric systems. This was a departure from earlier submarine power systems, which were direct drive types, little changed from the earliest boats. In this direct-drive power system, the diesel engine is directly connected to the propeller shaft.
Correspondent Scott Pelley takes a rare look inside the deadliest weapon ever built. It's a voyage on the Trident nuclear ballistic missile submarine. It's a doomsday machine, built to strike back if the United States is ever reduced to ashes in a nuclear holocaust. The Tridents have been on patrol for about 20 years. But while they've been sailing under the sea, the world above has changed.