A factory for inventions
In 1876 he built a laboratory at Menlo Park, where a team of technicians systematically tried out thousands of solutions. Edison thus invented not just individual devices, but also the way companies do research and development today.
Sound, light and current
In 1877 he unveiled the phonograph, the first device that could both record and play back sound. His carbon microphone improved the telephone. In 1879 he demonstrated a light bulb with a carbon filament that could stay lit for many hours, and in 1882 he opened the Pearl Street power plant in New York, which supplied homes and offices.
The first films
With his collaborator William Dickson he developed the kinetograph movie camera and the kinetoscope viewer. Out of these grew film, and later television.
The dispute with Tesla
Edison backed direct current, and lost. Alternating current, championed by Nikola Tesla and George Westinghouse, could be transmitted over long distances and became the standard. Edison's companies were later merged to form General Electric.