In 1883, Thomas Alva Edison discovered that electrons will flow from one metal conductor to another through a vacuum. Working with this effect, John Fleming developed an electron tube called a diode, and his works has inspired other scientists to create more advanced designs: a triode, a transistor, and finally an integrated circuit. At first, Electronics found its way into communications, from Marconi's wireless telegraph to transistor radios and then television; however, by the end of the 20th century they were virtually everywhere: in microcomputers, medical equipment, cars, household items, farms, offices, traffic lights, spaceships, and in every single niche of human activity.