Small Home Gazette, Winter 2023
Centennial Light Shines On
Since transitioning from incandescent to LED light bulbs throughout my bungalow, I have been feeling pretty smug. After all, LEDs are rated to last 15,000 to 20,000 hours, instead of the 1,000 or so offered by incandescent bulbs.
But then I ran across this: an incandescent bulb that has been burning almost continuously for well over a century—more than one million hours. And it is still going strong.
The Centennial Light, in action.
Behold the Centennial Light, located in Fire Station 6 in Livermore, California. It was first screwed into a socket in a Livermore firehouse in 1901. Because it has always lived in fire stations, it has burned 24 hours a day. It has been moved a couple of times, and survived occasional, brief power outages. But for all but a tiny fraction of its long life, it has been aglow. It glowed through WWI; through the bungalow era; through another world war; during the moon landing; and it lived to see scientists announce the nuclear fusion breakthrough this year. Talk about staying power.
Its long life is well documented—so much so that it qualified for listing in the Guinness Book of World Records; was featured in the TV program “On the Road With Charles Kuralt”; and was recognized by Ripley’s Believe-It-or-Not. Speaking of believe-it-or-not, the bulb has also been officially lauded, in writing, by President George W. Bush, Senator Barbara Boxer, and Congresswoman Ellen Tauscher. It was also featured in the award-winning 2010 film, The Light Bulb Conspiracy: The Untold Story of Planned Obsolescence.
At one time, you could purchase a replica of the Centennial Light. But they are no longer manufactured, and they probably would not have lasted a century anyway.
Why, you may ask, has this bulb lasted so long? Many have asked that question, including physicist Martin Kytka. You can read Kytka’s highly technical 2021 article, full of algebraic equations and mathematical tables, online. Or you can skip to this sentence in the paper’s last paragraph: “The reason it (the bulb’s filament) did not break is probably due to the strength and thickness of carbon fiber matrix…” In other words, the bulb was manufactured with a filament made not of short-lived tungsten, but of tough carbon fiber. The Centennial Light is still a marvel, however, as virtually all other carbon fiber bulbs have long since expired.
Would you like to see the Centennial Light? Visit centennialbulb.org for the Livermore fire station’s address and visiting hours. You can also watch a live video feed of the bulb online. Be forewarned: It is not very dynamic.
