On What Date Was the Light Bulb Invented?

date-light-bulb-invented Credit: Tim Robberts/The Image Bank/Getty Images

According to the US Department of Energy, Thomas Edison and his team had produced a functional incandescent light bulb by October 1879. Before this, British inventors had been experimenting with arc lamps. The first "constant electrical light" was invented in 1835, after which inventors continued to make small improvements until Edison's commercial breakthrough.

The history of the electric light begins in 1802 with Humphry Davy and his arc lamp. This was simply a battery wired to a piece of carbon, which fluoresced brightly for a short period. In the following decades, many others experimented with light bulb designs, beginning with British scientist Warren de la Rue. He invented the first enclosed electric light, which was a platinum filament in a vacuum tube.

Edison is famous because he and his team produced the first commercially viable light bulb. They first filed a patent on October 14, 1878. Most improvements to light bulbs during that period and since have focused on the material used for the filament and the combination of gases within the bulb. Today, incandescent bulbs are losing support in favor of more energy efficient options, such as compact fluorescent bulbs and LEDs.