Nikola Tesla (10 July 1856 - 7 January 1943) was an inventor, physicist, mechanical engineer, and electrical engineer. Born a Serbian, he was later granted American citizenship. Tesla is responsible for many revolutionary advances in the discipline of electricity and magnetism in the late 19th and early 20th century, and is credited as having pioneered modern electrical engineering, with which he helped usher in the Second Industrial Revolution.
Aside from his work on electromagnetism and engineering, Tesla is said to have contributed in varying degrees to the establishment of robotics, remote control, radar and computer science, and to the expansion of ballistics, nuclear physics, and theoretical physics. He is also credited as being the inventor of the radio, having successfully demonstrated wireless communication in 1893. Contemporary biographers of Tesla have deemed him "the man who invented the twentieth century" and "the patron saint of modern electricity."
While Tesla's fame rivaled that of any other inventor or scientist in history or popular culture at its peak, his eccentric personality and unbelievable and sometimes bizarre claims about possible scientific and technological developments led to his downfall. He was eventually ostracized and regarded as a "mad scientist" by the mainstream scientific community. Never having secured his finances, Tesla died impoverished at the age of 86.