Unless you literally live under a rock, you probably see one of these every day - the simple light bulb. So commonplace. So unassuming. But did you know that the light bulb actually has a fascinating history that dates back to the late 19th century? While Thomas Edison is often credited with its invention, there were actually a ton of inventors that contributed to its development (We actually wrote a blog about it).  

In 1879, Edison created a practical incandescent light bulb that lasted about 13.5 hours, but this was just the beginning. For instance, other inventors’ early bulbs used carbon filaments and could last around 40 hours, while others improved on this by developing a synthetic filament that lasted up to 500 hours. This collaborative spirit of innovation ultimately led to the widespread use of electric lighting in homes and businesses. 

Modern Technology of Light Bulbs 

Fast forward to today, and there are more types of light bulbs available on the market than I can count—the most common being incandescent, fluorescent, LED (light-emitting diode), and halogen bulbs. Fluorescent bulbs are more energy-efficient and last longer than incandescent ones, typically around 7,000 to 15,000 hours. However, the real game-changer has been LED technology, which can last anywhere from 15,000 to 50,000 hours or more.  

Now that sounds like a long time but it’s really only about 5 years. I mean, that’s still far better than where we started with bulbs burning for just short of 2 days, but don’t you think we can do better than that?  

Well, it turns out we can, and we did. 

The Centennial Bulb  

The Centennial Light Bulb is an incandescent bulb and the oldest light bulb still burning today. Incandescent bulbs generate light by running electricity through a filament until it gets so hot that it glows. The filament of the Centennial Light Bulb is about eight times thicker than bulbs of our time, as was standard for old incandescent bulbs. More pointedly, the filament is a semiconductor, a hybrid conductor-insulator substance used extensively in modern computers. The hotter it gets, the better it conducts electricity. 

The bulb was manufactured in Shelby, Ohio, by the Shelby Electric Company in the late 1890s. In 1901, Shelby’s owner, Dennis Bernal donated the bulb to his hometown’s fire department in Livermore, California, where it’s been ever since.  

The Centennial Bulb, as this light has come to be known, is the longest-lasting light bulb of all time. It has been burning continuously since 1901, (excluding a short interval in 1976 when the bulb was disconnected from electricity for 22 minutes while the fire station was being moved to a different location).  

Though today the bulb has dimmed from the 30-watt output of its beginnings to a comparatively meager four watts (about the output of an average night light), it still continues to burn — more than 123 years and 1 million hours of use later. With such a huge accomplishment, the Centennial Bulb was recognized as “the most durable light” by the Guinness Book of World Records in 1972 and is now listed as the “longest burning light bulb.” 

How is This Possible? 

The extraordinary thing about the Centennial Bulb is that it’s actually quite ordinary. Researchers haven’t been able to nail down the specifics of the design because it’s hard to examine while it’s illuminated, and no one is daring enough to unscrew the thing, but it’s thought to be a pretty generic design, similar to other bulbs made by the Shelby Electric Company back in the day.  

While part of its crazy long life might come from some special design features, it actually isn’t that weird for bulbs from way back in the day to last even longer than the ones we use today. That’s because this light bulb was manufactured before the life span of light bulbs was artificially set by lighting companies in the 1920s, as many now claim. 

We went into more detail about the planned obsolescence of lighting and other modern tech in an earlier blog (that you can read here), but the gist of this claim comes from a time when big names like Philips, Osram, and General Electric got together in Sweden to create the Phoebus Cartel. This cartel took massive control over the lighting industry and jacked up the prices of the traditional incandescent light bulb. At the same time, they slashed the life expectancy of those bulbs from 2,500 hours to just 1,000 hours, which pretty much tripled their profits.    

But the Centennial Bulb is a completely different story, free from those restrictions. With its own special regulated low voltage supply, the bulb is able to push past where many bulbs typically burn out. Running continuously also helps maintain a long life, as the thermal shock when a light is switched on accounts for most of the wear and tear on a filament lamp. 

LED’s have since changed the obsolescence issue, as companies like Sunco are developing bulbs that can last 35,000-50,000 hours. And while this is quite the feat, it’s nothing compared to the Centennial Bulb.

Will This Bulb Live Forever? 

Short answer? Probably not. But one thing is for sure—it’s lasted longer than any other bulb in the world. Using only 4 watts definitely contributes to its long life, and researchers expect this little light to shine for maybe 100 more years.  

“The light bulb isn’t burning out, but the webcams are,” one firefighter in the Livermore fire house joked. “We keep needing to change the damn things, but never the bulb.”  

You can keep up with the Centennial Bulb by checking in on its livestream here.