Did Thomas Edison really invent the light bulb?

Edison did not invent the first light bulb. The National Park Service, which runs Edison's historic site, says so directly. Inventors had been trying to light the world with electricity for at least fifty years before him. What Edison did was make an incandescent bulb that lasted long enough to be practical, and then build much of the system needed to power it in homes. [1] [2]

The US Department of Energy notes that British inventors showed electric light was possible with the arc lamp, and that the first constant electric light was demonstrated in 1835. Over the following forty years scientists worked on the incandescent lamp, adjusting the filament and the bulb's atmosphere. Those early bulbs had very short lifespans, cost too much to make, or used too much energy. Charles Brush began an arc lighting business in 1877, two years before Edison's breakthroughs with incandescent lighting. [3] [1]

BBC Science Focus names Alessandro Volta, Humphrey Davy, James Bowman Lindsay, Warren de la Rue and William Staite among those who contributed earlier. It describes the light bulb as a cumulative effort. [4]

Edison's team at Menlo Park tested many filament materials. In the fall of 1879 they carbonized a cotton thread, sealed it in an evacuated glass bulb, and it burned at least 13 hours. The Department of Energy gives 14.5 hours. The Park Service says the popular date of October 21 has been disproved by new research. The team later found that bamboo made a better filament, giving lamps a life of up to 1,200 hours, and it stayed standard for about ten years. [2] [3]

Edison's group also worked on a better vacuum pump, the Edison screw socket, dynamos, wiring, fuses, switches and meters. BBC Science Focus says that combining a thin carbon filament with better vacuums made him the first to solve both the scientific and the commercial problems of the bulb. [3] [1] [4]

Joseph Swan, a British chemist, is the person most often credited alongside Edison. BBC Science Focus says he gave public demonstrations of a working incandescent lamp in late 1878 and early 1879. After a UK court battle that sided with Swan's patent over another lamp maker's, the two men worked together under the Ediswan company. The Department of Energy adds that William Sawyer and Albon Man received a US patent for an incandescent lamp, and that there was debate over whether Edison's patents infringed on theirs. [4] [3]

A popular social media claim says Edison stole the bulb from Lewis Latimer. A Reuters fact check rates this misleading. Latimer made a major contribution by devising a longer-lasting carbon filament and filed a patent for manufacturing it in September 1881, but he did not invent the bulb itself. [5]

Smithsonian Magazine adds that in autumn 1878 Edison could not yet keep a bulb lit for more than a few minutes, and that he knew Swan was working on a rival bulb. [6]