Nikola Tesla (1856-1943) is best known for his contributions to the design of the modern alternating current electricity supply system. A pioneer in his field, he was always recognized as one of the foremost electrical researchers and inventors. Born in Croatia, he was interested in science at a young age. He was able to attend the techical college in Austria and worked in telephony before moving to the United States where he worked for Thomas Edison. After many disagreements with Edison, he began working on his own founding companies and laboratories. Westinghouse licensed his inventions on alternating current. Tesla is also known for his high-voltage, high-frequency power experiments in New York and Colorado Springs which included inventions and ideas used in the invention of radio communication, for his X-ray experiments, and for his attempt at worldwide wireless transmission. He became a famous scientist as well as a showman. He often announced new inventions and made sometimes wonderful pronouncements without results or proof. Therefore he gained a reputation in popular culture as a "mad scientist".Tesla's work fell into relative obscurity after his death, but since the 1990s, his reputation has experienced a well deserved comeback.