​Tesla 

Tesla demonstrating wireless transmission by “electrostatic induction” during an 1891 lecture at Columbia College.  The two metal sheets are connected to a Tesla coil oscillator, which applies high-voltage radio frequency alternating current.  An oscillating electric field between the sheets ionizes the low-pressure gas in the two long Geissler tubes in his hands, causing them to glow, similar to neon tubes.

After 1890 inventor Nikola Tesla experimented with transmitting power by inductive and capacitive coupling using spark-excited radio frequency resonant transformers, now called Tesla coils, which generated high AC voltages.[35][37][105] Early on he attempted to develop a wireless lighting system based on near-field inductive and capacitive coupling[37] and conducted a series of public demonstrations where he lit Geissler tubes and even incandescent light bulbs from across a stage.[37][105][106] He found he could increase the distance at which he could light a lamp by using a receiving LC circuit tuned to resonance with the transmitter’s LC circuit.[36] using resonant inductive coupling.[37][38] Tesla failed to make a commercial product out of his findings[107] but the resonant inductive coupling used is now a familiar technology used throughout electronics and is currently being widely applied to short-range wireless power systems.[37][108]

(left) Experiment in resonant inductive transfer by Tesla at Colorado Springs 1899. The coil is in resonance with Tesla’s magnifying transmitter nearby, powering the light bulb at bottom. (right) Tesla’s unsuccessful Wardenclyffe power station.

Tesla went on to develop a wireless power distribution system that he hoped would be capable of transmit power long distance directly into homes and factories. Early on he seemed to borrow from the ideas of Mahlon Loomis,[109][110] proposing a system composed of balloons to suspend transmitting and receiving electrodes in the air above 30,000 feet (9,100 m) in altitude, where he thought the pressure would allow him to send high voltages (millions of volts) long distances. To further study the conductive nature of low pressure air he set up a test facility at high altitude in Colorado Springs during 1899.[111][112][113] Experiments he conducted there with a large coil operating in the megavolts range, as well as observations he made of the electronic noise of lightning strikes, led him to incorrectly conclude[114][115] that he could use the entire globe of the Earth to conduct electrical energy. The theory included driving alternating current pulses into the Earth at its resonant frequency from a grounded Tesla coil working against an elevated capacitance to make the potential of the Earth oscillate. Tesla thought this would allowing alternating current to be received with a similar capacitive antenna tuned to resonance it at any point on Earth with very little power loss.[116][117][118] His observations also led him to believe a high voltage used in a coil at an elevation of a few hundred feet would “break the air stratum down”, eliminating the need for miles of cable hanging on balloons to create his atmospheric return circuit.[119][120] Tesla would go on the next year to propose a “World Wireless System” that was to broadcast both information and power worldwide[121][122] and attempted in 1901 to construct a large high-voltage wireless power station, now called the Wardenclyffe Tower, at Shoreham, New York. By 1904 investment dried up and the facility was never completed.