One of the great myths in the history of scientific innovation is that the man who invented the light bulb was Thomas Edison. However, this is simply not true. Although Edison did register a patent in 1879 for improvements to existing technologies, the story of the light bulb’s development actually began about 70 years prior to Edison’s patent.
The idea for the light bulb was originally conceived by Humphrey Davy in 1806. Although his invention was far from practical, he provided the impetus for the modern light bulb when he publicly demonstrated a crude device called the arc lamp. Davy’s lamp worked by creating an intense electric spark between two charcoal rods, which were connected to a battery he invented. The light produced by Davy’s lamp was extremely bright – similar to the light from a welding torch. Needless to say, Davy’s arc lamp provided much more light than was practical for use in homes, and the degree of power needed to illuminate the lamp drained the battery quickly.
The Development of the Light Bulb
Although Davy’s lamp was impractical for personal home use, it eventually found a number of useful applications as electric generators were developed to sustain the lamp. The electric arc lamps became valuable for lighting streets, lighthouses, and public meeting places where significant light sources were needed.
Throughout the 19th century, several inventors sought ways to harness light in smaller packages. British inventor Frederick DeMoleyns came up with the idea of enclosing the light source in a glass casing (i.e., a “bulb”). DeMoleyns’ invention isolated the burners – made of carbon and platinum – from the oxygen in the atmosphere, allowing the burners to last much longer without catching fire. An American inventor, J.W. Starr, further developed this technique and received a patent of his own in 1845.
In 1860, a British scientist named Joseph Swan also recognized the potential to improve incandescent lighting. He received a patent for a light bulb that used a carbon filament. However, even Swan’s much-improved version of the existing technologies was impractical. The carbon filament burned out too quickly, and these early light bulbs lacked the longevity we rely on today.
Edison and his team continued to improve the light bulb by searching for more effective materials to use in the filaments, ones that also had high electrical resistance – an essential feature to prevent the burning materials from getting too hot. The goal was to find a balance: a material hot enough to produce light, but not so hot that it would burn out too quickly. After extensive experimentation, Edison and his staff finally settled on carbonized bamboo as the filament material, and this became the innovation that set the standard for practical light bulbs.
So, while Edison did not exactly invent the light bulb, he perfected it in such a way that it could be used on a massive scale. The invention of the light bulb was truly the result of collaborative efforts by multiple scientists over many years.
