The World’s Longest Burning Lightbulb

December 21, 2022

This is one persistent lightbulb. The world’s longest-lasting lightbulb has been burning in a Livermore, California, fire station since 1901. That’s over 120 years that the bulb has been in operation with over 1,000,000 hours of use.

The discovery of the age of the lightbulb, known as the Centennial Light, was made in 1972 by a newspaper reporter who checked the records and interviewed people who knew about it. He found that the bulb at the time had been burning for 71 years. The story turned the Livermore fire station into a mini tourist attraction.

In 1976, The bulb made a two-mile move from the old Livermore Fire Department headquarters to a new home in Station № 6 with a full police escort. Electricians had carefully cut the cord and then rewired it at the new station. The bulb was out for 22 minutes before springing back to life when it was turned on once again. It lit up at its original 60 Watts for a few hours but then dimmed to what it was formerly through the years at 4 Watts.

The bulb has been off at other various times in its history. It was turned off in 1937 for a week when the firehouse was being renovated, and it was out for nine and a half hours in 2013 when a backup system failed in keeping it lit.

This particular bulb was invented by Adolphe Chaillet and made by the Shelby Electric Company. It is a 60 Watt, hand-blown lightbulb, with a carbon filament. It cost 40 cents in 1901.

There is no answer to why the bulb has burned so long, even though many have researched it. One idea believed for its longevity is because the filament is eight times thicker than a modern bulb. Another idea says that since the filament doesn’t burn as hot as a modern and thinner tungsten filament, the integrity of the filament has stayed intact. No one really knows for sure.

Sources: Los Angeles Times, Centennial (1), Centennial (2)

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Daniel Ganninger - The writer, editor, and chief lackey of Knowledge Stew, the author of the Knowledge Stew line of trivia books, and editor of Fact World and the Knowledge Stew sister site on Medium, our ad-free subscription sites (you can find out how to join below). I hope you find things here to annoy those around you with your new found knowledge.

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