The world's oldest functioning light bulb is 110 years old and still burning.
110 years ago, a competitor of Thomas Edison named Adolphe Chailet was making light bulbs to compete with Edison. Somehow, even though his light bulbs were nearly indestructible and said to never burn out (then again perhaps because of these properties; no recurring purchases if they never burn out), they never caught on. Nonetheless, at least one of Chailet's "Shelby" light bulbs is still burning, 110 years later.
Located at Fire Station 6 in Livermore, California, this Superbulb has survived several moves, many earthquakes, and even varying voltage (it went from 110 to 120 volts); it seems indestructible! The world's oldest still-burning light bulb is not an anomaly of its kind; even when it was built back in 1900, the Shelby-style light bulb was remarkable. During a series of challenges, Chailet's bulb proved to have the strongest filament, surviving increasing voltage levels while competitor light bulbs burned out. Not only did it survive, but it harnessed the voltage and just kept getting brighter!
Known to many as the Centennial Light, this light bulb burns all day and night. In its nearly 110 years of operation, it has been off for a grand total of only one week, during station renovations in 1937. It may not have the creativity or brightness of light bulbs today, but it has impossible durability.
Although I don't know the engineering behind the bulb or why it is so resilient, I can say that part of the reason it has operated for so long is precisely because it has been turned on and off so infrequently. It's the start-up phase that does damage to the filament; have you ever seen an incandescent light bulb fail during operation? If you have, you're in the minority, as the vast majority of incandescent light bulb failures occur on startup due to the voltage and electricity surge therein. In any case, an incandescent light bulb operating for over 100 years is incredible.
