The Big Blue Battery?
As Tesla studied high-frequency electricity, his growing fascination with transmitting energy wirelessly led him to invent the Tesla coil – a transformer capable of producing high-frequency alternating current -- as well as radio [sources: Cheney and Uth; Jonnes; PBS]. When he discovered that the Earth itself might transmit energy, he planned to build stations capable of powering the entire world [source: Jonnes].
Like any world-changing inventor, Tesla was a man of vision, and his career ran most smoothly when he could convey that vision to other pioneers. In 1893, his alternating current beat out Edison's direct current proposal to light the monumental World's Columbian Exposition in Chicago (aka the Chicago World's Fair). Not only did this event mark a turning point in the War of the Currents, it also enabled him to follow his grandest ambitions, including his childhood dream of harnessing the power of Niagara Falls [sources: Cheney and Uth; Jonnes; PBS].
Even after he'd won the Niagara contract, most of his backers remained dubious about whether Tesla's hydroelectric machines would work. The inventor did not. When the switch was thrown at midnight, Nov. 16, 1896, lights turned on in Buffalo, N.Y., 21 miles (34 kilometers) away. Within a few years, the station expanded its reach to New York City, roughly 400 miles (644 kilometers) away [sources: Cheney and Uth; Jonnes; PBS]. Tesla's youthful dream had come true.
Tesla also proposed controlling, or at least catalyzing, weather with electricity. He visualized transmitting power globally and, with it, information -- an early version of a global wireless communications system [sources: Cheney and Uth; PBS]. The scientist told investor J.P. Morgan, "When wireless is fully applied the Earth will be converted into a huge brain, capable of response in every one of its parts" [source: PBS].