There’s a light that never goes out… well, almost never.
Since the invention of commercial light bulbs in the late 19th century, one bulb has outshone all others. In 2025, it could enter its 124th year of working life.
Exactly when the 60-watt bulb was manufactured and the year it was first turned on are a bit unclear, but according to Guinness World Records, the so-called Centennial Light is the longest-burning light bulb in the world.
It currently casts a weak orange glow in a California fire station, like a lucky ‘nightlight’ that has rarely been turned off in all its years of life.
The ongoing illumination is a testament to the strength and longevity of the world’s first commercial light bulbs, and for many years now, it has burned on a live online cam for all to see. According to a 2016 New Yorker piece, the bulb has outlived three modern webcams.
In 2015, the Livermore Firefighters Foundation celebrated the Centennial Light for over a million hours of service.
In 2021, an engineer by the name of Martin Kykta, president of MAK Electro-Optics, studied the Centennial bulb’s anatomy and predicted that if it continues to emanate 4 watts or less, it could last for another century.
The persistent source of light was made famous in the 1970s when a newspaper investigation for the Herald News threw it in the ring for the world’s longest-burning bulb.
According to local accounts, the light bulb was first donated to a firehouse in Livermore, California in 1901, and while it changed locations a few times over the decades, the bulb is still with the local fire department.
The 1972 news report claims the bulb was ‘lighted’ in 1902, but the official Guinness World Record states it has been burning since 1901.
It was only ever turned off when necessary or by accident.
“It was left on 24 hours a day to break up the darkness so the volunteers could find their way,” the Livermore fire chief told reporter Mike Dunstan for the 1972 Herald News article.
“It was never turned off, except for about a week when President Roosevelt’s WPA people remodeled the fire house back in the ’30’s and a few times when we had power failures.”
Today, incandescent bulbs are notorious for their short lives, but in part, that is because they are regularly turned on and off, which exposes the tungsten wire inside to rapid expansion and contraction.
The Centennial bulb was made by a company called Shelby and it contains a carbon filament that doesn’t wear out as easily as tungsten. Even still, tungsten came to be the favorite for light bulbs in the 20th century, as it could tolerate exposure to oxygen better than carbon.
The Shelby light bulb is hand-blown, and its thick carbon wire is kept safely in a vacuum, where it maintains a steady low-watt gleam.
No one yet knows if LED bulbs can outperform the Shelby bulb, but today, the average LED light is said to last up to 50,000 hours, which is nearly six years. Even if they last up to 100,000 hours (which some suspect they might), that’s just over a decade of light.
It’ll take a lot more than that to compete with the Centennial bulb.
