The World’s Oldest Lightbulb: 125 Years and 1 Wild Conspiracy Theory

The world’s oldest lightbulb has been burning since 1901. That’s not a typo. It still glows today, inside a fire station in Livermore, California. People call it the Centennial Bulb. And for decades, conspiracy theorists have used it as “proof” that big companies deliberately make products break faster. The real story is stranger, and a lot more interesting.

Quick Facts

• The bulb was made in 1901 by Ohio’s Shelby Electric Company
• It has burned for more than one million hours
• It’s rated as a 60-watt bulb but only draws about four watts
• A real industry group, the Phoebus Cartel, did set a 1,000-hour lifespan standard in 1925

What Is the Centennial Bulb?

The Centennial Bulb hangs from a ceiling in Livermore, California. It’s been glowing, almost without interruption, for 125 years. Earlier this summer, people even gathered to sing it “Happy Birthday.” It’s a strange kind of celebrity. But its fame comes with baggage.

For years, people have pointed to this bulb as evidence of a cover-up. The claim goes like this: companies could easily make lightbulbs that last forever. They just choose not to. Instead, they build products to fail, so you keep buying more. This idea even has a name: planned obsolescence.

Why Don’t Modern Bulbs Last This Long?

To understand the real answer, you need a little physics. Old-style incandescent bulbs work by heating a thin metal filament until it glows. That filament is usually tungsten. Heat determines brightness. It also determines color.

To produce bright, white light, tungsten needs to hit roughly 5,700°C. That’s close to the surface temperature of the sun. There’s a problem, though. Tungsten melts at around 3,422°C, far below that ideal glowing point. So every bulb ever made has had to settle for less brightness than “perfect.”

Here’s the real catch. The hotter a filament burns, the brighter it shines. But heat also breaks it down faster. Atoms evaporate off a hot filament, thinning it out over time. Eventually, it snaps. This means every incandescent bulb faces the same tradeoff: burn bright and die fast, or burn dim and last long.

The Phoebus Cartel: Real Conspiracy, Real Limits

Here’s where the conspiracy theory has a grain of truth. In 1925, a group of major lightbulb makers, including Philips and General Electric, formed something called the Phoebus Cartel. It was real. It did fix prices. And it did set a shared industry standard: bulbs should last around 1,000 hours.

The cartel fell apart around 1939, as World War II reshaped global industry. But that 1,000-hour benchmark stuck around for decades. To conspiracy theorists, this looks like smoking-gun proof. A secret group agreeing to make products worse, on purpose, forever.

But that’s not quite what happened.

So Why Has the World’s Oldest Lightbulb Survived?

The real explanation is almost anticlimactic. According to research from independent researchers who’ve studied the bulb’s design, the Centennial Bulb was likely a manufacturing accident. Someone at Shelby Electric Company appears to have built a handmade filament with unusually high resistance.

That accident changed everything. The bulb draws only about four watts of power, despite being labeled 60 watts. And even at four watts, it’s dimmer than a normal four-watt bulb would be, because it runs so inefficiently. In plain terms: it barely produces any light at all. That’s exactly why it’s lasted so long. A dim, weak glow puts far less stress on a filament than a bright one does.

In other words, the Centennial Bulb isn’t proof that companies could make every bulb last forever. It’s proof of the opposite. Making a bulb last this long means making it nearly useless as a light source.

What This Means for “Planned Obsolescence”

None of this means companies never cut corners. Plenty of industries genuinely have used shortsighted, wasteful manufacturing choices over the decades. But the classic lightbulb story doesn’t hold up as a clean example.

Standardizing a 1,000-hour lifespan wasn’t purely about greed. It also gave consumers something valuable: predictable brightness, at a predictable cost, for a predictable price. A world full of dim, barely-visible “eternal” bulbs wouldn’t have actually served anyone well.

Eventually, the entire debate became moot anyway. Incandescent bulbs got replaced by fluorescent and LED lighting, which last longer, cost less to run, and don’t force the same brightness-versus-lifespan tradeoff. Technology moved past the argument entirely.

If you’re curious how tiny engineering tradeoffs like this show up elsewhere in daily life, our explainer on how rockets balance power against efficiency covers a very similar kind of engineering compromise, just at a much larger scale.

Frequently Asked Questions

What is the world’s oldest lightbulb?
It’s the Centennial Bulb, made in 1901 by Ohio’s Shelby Electric Company. It still glows today inside Fire Station #6 in Livermore, California.

How is the world’s oldest lightbulb still working?
It likely has an unusually high-resistance filament, possibly a manufacturing accident. That makes it draw very little power and glow extremely dim, which puts much less stress on the filament than a normal bulb experiences.

Is planned obsolescence real?
Some industries have genuinely used it. But the classic lightbulb example is more complicated than it first appears. The 1925 Phoebus Cartel did set a 1,000-hour lifespan standard, but that decision balanced brightness, cost, and lifespan rather than existing purely to force people to keep buying.

Why don’t all lightbulbs last as long as the Centennial Bulb?
Because a bulb that lasts that long has to run extremely dim. Brighter bulbs burn their filaments faster. No incandescent bulb can be both very bright and extremely long-lasting at the same time.

Final Thoughts

The world’s oldest lightbulb isn’t hiding some grand corporate secret. It’s a quirky manufacturing accident that happened to be too dim to ever burn out. Sometimes the real explanation is less dramatic than the myth. But it’s still a pretty remarkable story.

Source: Popular Science, “The world’s oldest lightbulb has been shining for 125 years”