Nikola Tesla (1856-1943) was a Serbian-American engineer and inventor, known for his work on alternating current and electricity. After working in telephony and electrical engineering, Tesla immigrated to the US, and worked with Thomas Edison. Later, the two men separated on bad terms. Tesla was part of what was called 'the war of currents,' when Edison and his Direct Current (DC) were battling Westinghouse's Alternating Current (AC) for the conquest of electric distribution in the United States. Tesla was facing Edison again on this occasion. Reputed to be some kind of mad scientist, Tesla has worked on many fields, including Radio, X-Rays and direct-energy weapons.