The Centennial Light bulb is the world’s longest-burning light bulb, according to Guinness World Records. It has been continuously illuminated since 1901 at a fire station in Livermore, California.
The bulb, a 60-watt incandescent lamp made by the Shelby Electric Company, has been burning for over 120 years as of 2025. It casts a weak orange glow and has outlived multiple webcams set up to livestream its burning.
In 2015, the bulb was celebrated for over 1 million hours of service. An engineer predicted in 2021 that if it continues to use 4 watts or less, it could last for another century.
The long lifespan of the Centennial Light is attributed to its carbon filament design, which is kept in a vacuum and doesn’t wear out as easily as the more common tungsten filament. Incandescent bulbs today typically last only a few thousand hours, as they are regularly turned on and off, causing rapid expansion and contraction of the filament.
Even modern LED bulbs, which can last up to 100,000 hours, are unlikely to match the longevity of the Centennial Light anytime soon. This historic bulb continues to defy the normal lifespan of commercial light bulbs.
Source: ScienceAlert
