Who Invented the Light Bulb?
Orbiting high above the Earth, the Hubble Space Telescope has been one of the most successful space missions in history. The spacecraft has returned hundreds of thousands of images of some of the most distant and spectacular objects in the Universe and rewritten our understanding of the cosmos.
The success of the Hubble can be attributed to thousands of people who built, launched, operated, and repaired the orbiting observatory over the past two decades. But, there has been another secret to the telescope’s success over the years that gets very little attention: tungsten light bulbs.
The bulbs are aboard Hubble to help astronomers calibrate the spacecraft’s instrument. In the same way that astronomers test their ground-base telescopes with light bulbs, so it is done with the multi-billion dollar space observatory.
It’s a good bet that few imagined the light bulb flying high above Earth when it was created back in the 19th century. Those who invented the light bulb were simply looking for alternatives to oil lamps and candles that had been used for thousands of years.
Thomas Edison and British inventor Joseph Swan can both lay claim to having invented practical light bulbs that were commercially viable. However, they were building on the work of nearly two dozen inventors who came before them.
British inventor Humphry Davy invented an early light bulb in 1802. Davy’s incandescent light was neither especially bright nor long lasting, but it did kick off decades of experimentation in the United States, Western Europe, and Russia. However, none of the light bulbs proved to be commercially viable for nearly 80 years.
In the 1870s, Edison in America and Swan in Britain began parallel light bulb development efforts. Edison filed a patent application for an "improvement in electric lights" on Oct. 14, 1878. The patent was for an incandescent light that used carbon filament.
During the same period, Swan was developing a method for preventing the blackening process that rendered many early light bulbs ineffective. He also invented a better carbon filament that required far less current and lasted far longer than other materials. Swan received patents for both inventions in 1880.
Both Edison and Swan formed companies to produce light bulbs in mass quantities. Swan’s house was the first in the world to use light bulbs. In 1881, the Savoy Theatre in London became the first public building in the world to be lit entirely by electricity. In Britain, the two inventors merged their companies into the Edison and Swan United Electric Company, also known as Ediswan.
Since that time, many improvements have been made in light bulbs. The tungsten bulbs that are used on the Hubble Space Telescope were invented in 1904 by Hungarian Sándor Just and Croatian Franjo Hanaman. The tungsten filament outlasted all other types, which is important when you’re operating on a space telescope that goes years without maintenance.