English: Serbian-American inventor Nikola Tesla demonstrating wireless power transmission, probably in his New York laboratory in the 1890s. The bulb is a prototype "fluorescent" light he invented consisting of a partially evacuated glass bulb with a single metal electrode. Nearby but not visible there is one of his Tesla coil high voltage oscillators which produces a radio frequency electric field. The electric field ionizes the gas in the bulb, causing it to glow similar to a neon light. Tesla invented a residential wireless lighting system in the 1889s.