Incandescent light bulb
Electric light producing illumination by Joule heating a filament.
The incandescent light bulb, also known as an incandescent lamp or incandescent light globe, is an electric light that produces illumination by Joule heating a filament until it glows. It became widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting, due to its low manufacturing costs and ability to work on either alternating current or direct current. However, incandescent bulbs are much less efficient than other types of electric lighting, converting less than 5% of consumed energy into visible light, which has led to a decline in market share and government bans aimed at reducing energy consumption.
- field
- Electric lighting
- known_for
- First practical electric light source for widespread use
- key_inventors
- Joseph Swan, Thomas Edison, and others including Henry Woodward and Mathew Evans
Lore & Background
Historians Robert Friedel and Paul Israel list inventors of incandescent lamps prior to Joseph Swan and Thomas Edison of General Electric. They conclude that Edison's version was the first practical implementation, able to outstrip the others because of a combination of four factors: an effective incandescent material; a vacuum higher than other implementations; a high resistance that made power distribution from a centralized source economically viable; and the development of the associated components required for a large-scale lighting system. Historian Thomas Hughes has attributed Edison's business success to his development of an entire, integrated system of electric lighting, noting that the lamp was a small component in his system and no more critical than the Edison Jumbo generator, the Edison main and feeder, and the parallel-distribution system. Over the first three-quarters of the 19th century, many experimenters worked with various combinations of platinum or iridium wires, carbon rods, and evacuated or semi-evacuated enclosures.
Reader's Guide
The incandescent light bulb's significance lies in its role as the first practical electric light source for widespread use, enabling the electrification of homes, businesses, and public spaces. Its development involved numerous inventors over the 19th century, with Joseph Swan and Thomas Edison emerging as key figures. Edison's success is attributed not just to the bulb itself but to his creation of an entire integrated system of electric lighting, including generators, distribution lines, and parallel circuits. The bulb's low manufacturing costs and compatibility with both AC and DC power made it ubiquitous for over a century. However, its low efficiency—less than 5% of energy converted to visible light—led to a decline in market share compared to compact fluorescent and LED bulbs, accelerated by government bans aimed at reducing energy consumption. These bans have been controversial in some cases. The legacy of the incandescent bulb is thus one of transformative technology that eventually gave way to more efficient alternatives.
Did You Know?
- Less than 5% of the energy consumed by an incandescent bulb is converted into visible light; the rest is released as heat.
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