Few inventors contributed more to advances in science and engineering in the early 20th century than Nikola Tesla. As one of the Fathers of Electricity, Tesla did groundbreaking work on alternating current (AC) power system, electromagnetism, hydroelectric power, radio, and radar to name a few. Many of his inventions (Tesla obtained some 300 patents in his lifetime) became the stuff we take for granted today: when we flip a switch to turn on the light, we owe a lot of that electrical magic to Tesla.
As fate would have it, Tesla, one of the world’s greatest inventors, died penniless and in obscurity. Even today, many people mistakenly attribute many of his inventions to others (Edison, for example, is in the name of many power companies in the United States – ironically, they use the AC system devised by Tesla rather than the more inefficient direct current or DC system espoused by Thomas Edison; Tesla also invented the fundamentals of radio transmissions before Gugliegmo Marconi).
Today, there’s quite a bit of resurgence in Tesla’s popularity, which is helped in part by his mystique as a "mad scientist." Amongst his more outlandish ideas, Tesla worked on death rays to knock out enemy airplanes out of the skies, pocket-sized resonance machine that could topple buildings, ways to send electricity through the upper atmosphere, force-fields to protect cities, and so on.
Read the story of Tesla's life and inventions, along with plenty of photographs, in an excerpt from the book Tesla: Master of Lightning by Margaret Cheney and Robert Uth. Link