A lightbulb has been illuminating a firehouse in Livermore, CA continuously for more than 100 years. Known as the Centennial Light, the hand-blown carbon filament lightbulb has only been turned off a handful of times. The bulb is now attached to a generator to minimize future power disruptions. To see for yourself, check out this 24-hour live web feed of the bulb.
As unlikely as it may seem, the Centennial light is not the only lightbulb that has been burning for an improbably long time. The Palace Theater lightbulb in Fort Worth, TX, has been burning almost as long. Theories as to why these lightbulbs could last so long include that these bulbs have a particularly perfect vacuum seal, that the lights have been turned on and off minimally and that the bulbs are powered at low wattage.
In a similarly surprising story, GE found earlier this year that a 100 year old lightbulb that had been a part of a time capsule still emitted light. The lightbulb had been packed in sand for 100 years, but turned on when screwed into a modern light socket.
These old lightbulbs rely on the original incandescent technology developed by scientists in the 1800′s and made practical by Thomas Edison. The filament in these bulbs produces light in an inefficient process when an electric current is applied. When the filament breaks, the bulb no longer produces light. Incandescent lightbulbs are still used today with an average lifetime of 1200 hours. Other lightbulbs used today, like compact fluorescent lightbulbs and LED bulbs produce light by other, more energetically efficient processes and have lifetimes that are 10-50 times longer than an incandescent. Perhaps as these technologies are perfected, we can all have a centennial lightbulb in our homes.